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}.
5820 The @code{#:package} parameter can be passed to specify a package name, which
5821 is useful when a package contains multiple packages and you want to build
5822 only one of them. This is equivalent to passing the @code{-p} argument to
5826 @defvr {Scheme Variable} go-build-system
5827 This variable is exported by @code{(guix build-system go)}. It
5828 implements a build procedure for Go packages using the standard
5829 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
5830 Go build mechanisms}.
5832 The user is expected to provide a value for the key @code{#:import-path}
5833 and, in some cases, @code{#:unpack-path}. The
5834 @url{https://golang.org/doc/code.html#ImportPaths, import path}
5835 corresponds to the file system path expected by the package's build
5836 scripts and any referring packages, and provides a unique way to
5837 refer to a Go package. It is typically based on a combination of the
5838 package source code's remote URI and file system hierarchy structure. In
5839 some cases, you will need to unpack the package's source code to a
5840 different directory structure than the one indicated by the import path,
5841 and @code{#:unpack-path} should be used in such cases.
5843 Packages that provide Go libraries should install their source code into
5844 the built output. The key @code{#:install-source?}, which defaults to
5845 @code{#t}, controls whether or not the source code is installed. It can
5846 be set to @code{#f} for packages that only provide executable files.
5849 @defvr {Scheme Variable} glib-or-gtk-build-system
5850 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
5851 is intended for use with packages making use of GLib or GTK+.
5853 This build system adds the following two phases to the ones defined by
5854 @var{gnu-build-system}:
5857 @item glib-or-gtk-wrap
5858 The phase @code{glib-or-gtk-wrap} ensures that programs in
5859 @file{bin/} are able to find GLib ``schemas'' and
5860 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
5861 modules}. This is achieved by wrapping the programs in launch scripts
5862 that appropriately set the @code{XDG_DATA_DIRS} and @code{GTK_PATH}
5863 environment variables.
5865 It is possible to exclude specific package outputs from that wrapping
5866 process by listing their names in the
5867 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
5868 when an output is known not to contain any GLib or GTK+ binaries, and
5869 where wrapping would gratuitously add a dependency of that output on
5872 @item glib-or-gtk-compile-schemas
5873 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
5874 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
5875 GSettings schemas} of GLib are compiled. Compilation is performed by the
5876 @command{glib-compile-schemas} program. It is provided by the package
5877 @code{glib:bin} which is automatically imported by the build system.
5878 The @code{glib} package providing @command{glib-compile-schemas} can be
5879 specified with the @code{#:glib} parameter.
5882 Both phases are executed after the @code{install} phase.
5885 @defvr {Scheme Variable} guile-build-system
5886 This build system is for Guile packages that consist exclusively of Scheme
5887 code and that are so lean that they don't even have a makefile, let alone a
5888 @file{configure} script. It compiles Scheme code using @command{guild
5889 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
5890 installs the @file{.scm} and @file{.go} files in the right place. It also
5891 installs documentation.
5893 This build system supports cross-compilation by using the @code{--target}
5894 option of @command{guild compile}.
5896 Packages built with @code{guile-build-system} must provide a Guile package in
5897 their @code{native-inputs} field.
5900 @defvr {Scheme Variable} minify-build-system
5901 This variable is exported by @code{(guix build-system minify)}. It
5902 implements a minification procedure for simple JavaScript packages.
5904 It adds @code{uglify-js} to the set of inputs and uses it to compress
5905 all JavaScript files in the @file{src} directory. A different minifier
5906 package can be specified with the @code{#:uglify-js} parameter, but it
5907 is expected that the package writes the minified code to the standard
5910 When the input JavaScript files are not all located in the @file{src}
5911 directory, the parameter @code{#:javascript-files} can be used to
5912 specify a list of file names to feed to the minifier.
5915 @defvr {Scheme Variable} ocaml-build-system
5916 This variable is exported by @code{(guix build-system ocaml)}. It implements
5917 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
5918 of choosing the correct set of commands to run for each package. OCaml
5919 packages can expect many different commands to be run. This build system will
5922 When the package has a @file{setup.ml} file present at the top-level, it will
5923 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
5924 @code{ocaml setup.ml -install}. The build system will assume that this file
5925 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
5926 care of setting the prefix and enabling tests if they are not disabled. You
5927 can pass configure and build flags with the @code{#:configure-flags} and
5928 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
5929 set of flags used to enable tests. The @code{#:use-make?} key can be used to
5930 bypass this system in the build and install phases.
5932 When the package has a @file{configure} file, it is assumed that it is a
5933 hand-made configure script that requires a different argument format than
5934 in the @code{gnu-build-system}. You can add more flags with the
5935 @code{#:configure-flags} key.
5937 When the package has a @file{Makefile} file (or @code{#:use-make?} is
5938 @code{#t}), it will be used and more flags can be passed to the build and
5939 install phases with the @code{#:make-flags} key.
5941 Finally, some packages do not have these files and use a somewhat standard
5942 location for its build system. In that case, the build system will run
5943 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
5944 providing the path to the required findlib module. Additional flags can
5945 be passed via the @code{#:build-flags} key. Install is taken care of by
5946 @command{opam-installer}. In this case, the @code{opam} package must
5947 be added to the @code{native-inputs} field of the package definition.
5949 Note that most OCaml packages assume they will be installed in the same
5950 directory as OCaml, which is not what we want in guix. In particular, they
5951 will install @file{.so} files in their module's directory, which is usually
5952 fine because it is in the OCaml compiler directory. In guix though, these
5953 libraries cannot be found and we use @code{CAML_LD_LIBRARY_PATH}. This
5954 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
5955 @file{.so} libraries should be installed.
5958 @defvr {Scheme Variable} python-build-system
5959 This variable is exported by @code{(guix build-system python)}. It
5960 implements the more or less standard build procedure used by Python
5961 packages, which consists in running @code{python setup.py build} and
5962 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
5964 For packages that install stand-alone Python programs under @code{bin/},
5965 it takes care of wrapping these programs so that their @code{PYTHONPATH}
5966 environment variable points to all the Python libraries they depend on.
5968 Which Python package is used to perform the build can be specified with
5969 the @code{#:python} parameter. This is a useful way to force a package
5970 to be built for a specific version of the Python interpreter, which
5971 might be necessary if the package is only compatible with a single
5972 interpreter version.
5974 By default guix calls @code{setup.py} under control of
5975 @code{setuptools}, much like @command{pip} does. Some packages are not
5976 compatible with setuptools (and pip), thus you can disable this by
5977 setting the @code{#:use-setuptools} parameter to @code{#f}.
5980 @defvr {Scheme Variable} perl-build-system
5981 This variable is exported by @code{(guix build-system perl)}. It
5982 implements the standard build procedure for Perl packages, which either
5983 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
5984 followed by @code{Build} and @code{Build install}; or in running
5985 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
5986 @code{make} and @code{make install}, depending on which of
5987 @code{Build.PL} or @code{Makefile.PL} is present in the package
5988 distribution. Preference is given to the former if both @code{Build.PL}
5989 and @code{Makefile.PL} exist in the package distribution. This
5990 preference can be reversed by specifying @code{#t} for the
5991 @code{#:make-maker?} parameter.
5993 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
5994 passes flags specified by the @code{#:make-maker-flags} or
5995 @code{#:module-build-flags} parameter, respectively.
5997 Which Perl package is used can be specified with @code{#:perl}.
6000 @defvr {Scheme Variable} r-build-system
6001 This variable is exported by @code{(guix build-system r)}. It
6002 implements the build procedure used by @uref{http://r-project.org, R}
6003 packages, which essentially is little more than running @code{R CMD
6004 INSTALL --library=/gnu/store/@dots{}} in an environment where
6005 @code{R_LIBS_SITE} contains the paths to all R package inputs. Tests
6006 are run after installation using the R function
6007 @code{tools::testInstalledPackage}.
6010 @defvr {Scheme Variable} rakudo-build-system
6011 This variable is exported by @code{(guix build-system rakudo)} It
6012 implements the build procedure used by @uref{https://rakudo.org/,
6013 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
6014 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
6015 installs the binaries, library files and the resources, as well as wrap
6016 the files under the @code{bin/} directory. Tests can be skipped by
6017 passing @code{#f} to the @code{tests?} parameter.
6019 Which rakudo package is used can be specified with @code{rakudo}.
6020 Which perl6-tap-harness package used for the tests can be specified with
6021 @code{#:prove6} or removed by passing @code{#f} to the
6022 @code{with-prove6?} parameter.
6023 Which perl6-zef package used for tests and installing can be specified
6024 with @code{#:zef} or removed by passing @code{#f} to the
6025 @code{with-zef?} parameter.
6028 @defvr {Scheme Variable} texlive-build-system
6029 This variable is exported by @code{(guix build-system texlive)}. It is
6030 used to build TeX packages in batch mode with a specified engine. The
6031 build system sets the @code{TEXINPUTS} variable to find all TeX source
6032 files in the inputs.
6034 By default it runs @code{luatex} on all files ending on @code{ins}. A
6035 different engine and format can be specified with the
6036 @code{#:tex-format} argument. Different build targets can be specified
6037 with the @code{#:build-targets} argument, which expects a list of file
6038 names. The build system adds only @code{texlive-bin} and
6039 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
6040 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
6041 and @code{#:texlive-latex-base}, respectively.
6043 The @code{#:tex-directory} parameter tells the build system where to
6044 install the built files under the texmf tree.
6047 @defvr {Scheme Variable} ruby-build-system
6048 This variable is exported by @code{(guix build-system ruby)}. It
6049 implements the RubyGems build procedure used by Ruby packages, which
6050 involves running @code{gem build} followed by @code{gem install}.
6052 The @code{source} field of a package that uses this build system
6053 typically references a gem archive, since this is the format that Ruby
6054 developers use when releasing their software. The build system unpacks
6055 the gem archive, potentially patches the source, runs the test suite,
6056 repackages the gem, and installs it. Additionally, directories and
6057 tarballs may be referenced to allow building unreleased gems from Git or
6058 a traditional source release tarball.
6060 Which Ruby package is used can be specified with the @code{#:ruby}
6061 parameter. A list of additional flags to be passed to the @command{gem}
6062 command can be specified with the @code{#:gem-flags} parameter.
6065 @defvr {Scheme Variable} waf-build-system
6066 This variable is exported by @code{(guix build-system waf)}. It
6067 implements a build procedure around the @code{waf} script. The common
6068 phases---@code{configure}, @code{build}, and @code{install}---are
6069 implemented by passing their names as arguments to the @code{waf}
6072 The @code{waf} script is executed by the Python interpreter. Which
6073 Python package is used to run the script can be specified with the
6074 @code{#:python} parameter.
6077 @defvr {Scheme Variable} scons-build-system
6078 This variable is exported by @code{(guix build-system scons)}. It
6079 implements the build procedure used by the SCons software construction
6080 tool. This build system runs @code{scons} to build the package,
6081 @code{scons test} to run tests, and then @code{scons install} to install
6084 Additional flags to be passed to @code{scons} can be specified with the
6085 @code{#:scons-flags} parameter. The version of Python used to run SCons
6086 can be specified by selecting the appropriate SCons package with the
6087 @code{#:scons} parameter.
6090 @defvr {Scheme Variable} haskell-build-system
6091 This variable is exported by @code{(guix build-system haskell)}. It
6092 implements the Cabal build procedure used by Haskell packages, which
6093 involves running @code{runhaskell Setup.hs configure
6094 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
6095 Instead of installing the package by running @code{runhaskell Setup.hs
6096 install}, to avoid trying to register libraries in the read-only
6097 compiler store directory, the build system uses @code{runhaskell
6098 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
6099 addition, the build system generates the package documentation by
6100 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
6101 is passed. Optional Haddock parameters can be passed with the help of
6102 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
6103 not found, the build system looks for @code{Setup.lhs} instead.
6105 Which Haskell compiler is used can be specified with the @code{#:haskell}
6106 parameter which defaults to @code{ghc}.
6109 @defvr {Scheme Variable} dub-build-system
6110 This variable is exported by @code{(guix build-system dub)}. It
6111 implements the Dub build procedure used by D packages, which
6112 involves running @code{dub build} and @code{dub run}.
6113 Installation is done by copying the files manually.
6115 Which D compiler is used can be specified with the @code{#:ldc}
6116 parameter which defaults to @code{ldc}.
6119 @defvr {Scheme Variable} emacs-build-system
6120 This variable is exported by @code{(guix build-system emacs)}. It
6121 implements an installation procedure similar to the packaging system
6122 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
6124 It first creates the @code{@var{package}-autoloads.el} file, then it
6125 byte compiles all Emacs Lisp files. Differently from the Emacs
6126 packaging system, the Info documentation files are moved to the standard
6127 documentation directory and the @file{dir} file is deleted. Each
6128 package is installed in its own directory under
6129 @file{share/emacs/site-lisp/guix.d}.
6132 @defvr {Scheme Variable} font-build-system
6133 This variable is exported by @code{(guix build-system font)}. It
6134 implements an installation procedure for font packages where upstream
6135 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
6136 need to be copied into place. It copies font files to standard
6137 locations in the output directory.
6140 @defvr {Scheme Variable} meson-build-system
6141 This variable is exported by @code{(guix build-system meson)}. It
6142 implements the build procedure for packages that use
6143 @url{http://mesonbuild.com, Meson} as their build system.
6145 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
6146 of inputs, and they can be changed with the parameters @code{#:meson}
6147 and @code{#:ninja} if needed. The default Meson is
6148 @code{meson-for-build}, which is special because it doesn't clear the
6149 @code{RUNPATH} of binaries and libraries when they are installed.
6151 This build system is an extension of @var{gnu-build-system}, but with the
6152 following phases changed to some specific for Meson:
6157 The phase runs @code{meson} with the flags specified in
6158 @code{#:configure-flags}. The flag @code{--build-type} is always set to
6159 @code{plain} unless something else is specified in @code{#:build-type}.
6162 The phase runs @code{ninja} to build the package in parallel by default, but
6163 this can be changed with @code{#:parallel-build?}.
6166 The phase runs @code{ninja} with the target specified in @code{#:test-target},
6167 which is @code{"test"} by default.
6170 The phase runs @code{ninja install} and can not be changed.
6173 Apart from that, the build system also adds the following phases:
6178 This phase ensures that all binaries can find the libraries they need.
6179 It searches for required libraries in subdirectories of the package being
6180 built, and adds those to @code{RUNPATH} where needed. It also removes
6181 references to libraries left over from the build phase by
6182 @code{meson-for-build}, such as test dependencies, that aren't actually
6183 required for the program to run.
6185 @item glib-or-gtk-wrap
6186 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6187 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6189 @item glib-or-gtk-compile-schemas
6190 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6191 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6195 Lastly, for packages that do not need anything as sophisticated, a
6196 ``trivial'' build system is provided. It is trivial in the sense that
6197 it provides basically no support: it does not pull any implicit inputs,
6198 and does not have a notion of build phases.
6200 @defvr {Scheme Variable} trivial-build-system
6201 This variable is exported by @code{(guix build-system trivial)}.
6203 This build system requires a @code{#:builder} argument. This argument
6204 must be a Scheme expression that builds the package output(s)---as
6205 with @code{build-expression->derivation} (@pxref{Derivations,
6206 @code{build-expression->derivation}}).
6216 Conceptually, the @dfn{store} is the place where derivations that have
6217 been built successfully are stored---by default, @file{/gnu/store}.
6218 Sub-directories in the store are referred to as @dfn{store items} or
6219 sometimes @dfn{store paths}. The store has an associated database that
6220 contains information such as the store paths referred to by each store
6221 path, and the list of @emph{valid} store items---results of successful
6222 builds. This database resides in @file{@var{localstatedir}/guix/db},
6223 where @var{localstatedir} is the state directory specified @i{via}
6224 @option{--localstatedir} at configure time, usually @file{/var}.
6226 The store is @emph{always} accessed by the daemon on behalf of its clients
6227 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
6228 connect to the daemon over a Unix-domain socket, send requests to it,
6229 and read the result---these are remote procedure calls, or RPCs.
6232 Users must @emph{never} modify files under @file{/gnu/store} directly.
6233 This would lead to inconsistencies and break the immutability
6234 assumptions of Guix's functional model (@pxref{Introduction}).
6236 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
6237 how to check the integrity of the store and attempt recovery from
6238 accidental modifications.
6241 The @code{(guix store)} module provides procedures to connect to the
6242 daemon, and to perform RPCs. These are described below. By default,
6243 @code{open-connection}, and thus all the @command{guix} commands,
6244 connect to the local daemon or to the URI specified by the
6245 @code{GUIX_DAEMON_SOCKET} environment variable.
6247 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
6248 When set, the value of this variable should be a file name or a URI
6249 designating the daemon endpoint. When it is a file name, it denotes a
6250 Unix-domain socket to connect to. In addition to file names, the
6251 supported URI schemes are:
6256 These are for Unix-domain sockets.
6257 @code{file:///var/guix/daemon-socket/socket} is equivalent to
6258 @file{/var/guix/daemon-socket/socket}.
6261 @cindex daemon, remote access
6262 @cindex remote access to the daemon
6263 @cindex daemon, cluster setup
6264 @cindex clusters, daemon setup
6265 These URIs denote connections over TCP/IP, without encryption nor
6266 authentication of the remote host. The URI must specify the host name
6267 and optionally a port number (by default port 44146 is used):
6270 guix://master.guix.example.org:1234
6273 This setup is suitable on local networks, such as clusters, where only
6274 trusted nodes may connect to the build daemon at
6275 @code{master.guix.example.org}.
6277 The @code{--listen} option of @command{guix-daemon} can be used to
6278 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
6282 @cindex SSH access to build daemons
6283 These URIs allow you to connect to a remote daemon over
6284 SSH@footnote{This feature requires Guile-SSH (@pxref{Requirements}).}.
6285 A typical URL might look like this:
6288 ssh://charlie@@guix.example.org:22
6291 As for @command{guix copy}, the usual OpenSSH client configuration files
6292 are honored (@pxref{Invoking guix copy}).
6295 Additional URI schemes may be supported in the future.
6297 @c XXX: Remove this note when the protocol incurs fewer round trips
6298 @c and when (guix derivations) no longer relies on file system access.
6300 The ability to connect to remote build daemons is considered
6301 experimental as of @value{VERSION}. Please get in touch with us to
6302 share any problems or suggestions you may have (@pxref{Contributing}).
6306 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
6307 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
6308 @var{reserve-space?} is true, instruct it to reserve a little bit of
6309 extra space on the file system so that the garbage collector can still
6310 operate should the disk become full. Return a server object.
6312 @var{file} defaults to @var{%default-socket-path}, which is the normal
6313 location given the options that were passed to @command{configure}.
6316 @deffn {Scheme Procedure} close-connection @var{server}
6317 Close the connection to @var{server}.
6320 @defvr {Scheme Variable} current-build-output-port
6321 This variable is bound to a SRFI-39 parameter, which refers to the port
6322 where build and error logs sent by the daemon should be written.
6325 Procedures that make RPCs all take a server object as their first
6328 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
6329 @cindex invalid store items
6330 Return @code{#t} when @var{path} designates a valid store item and
6331 @code{#f} otherwise (an invalid item may exist on disk but still be
6332 invalid, for instance because it is the result of an aborted or failed
6335 A @code{&store-protocol-error} condition is raised if @var{path} is not
6336 prefixed by the store directory (@file{/gnu/store}).
6339 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
6340 Add @var{text} under file @var{name} in the store, and return its store
6341 path. @var{references} is the list of store paths referred to by the
6342 resulting store path.
6345 @deffn {Scheme Procedure} build-derivations @var{server} @var{derivations}
6346 Build @var{derivations} (a list of @code{<derivation>} objects or
6347 derivation paths), and return when the worker is done building them.
6348 Return @code{#t} on success.
6351 Note that the @code{(guix monads)} module provides a monad as well as
6352 monadic versions of the above procedures, with the goal of making it
6353 more convenient to work with code that accesses the store (@pxref{The
6357 @i{This section is currently incomplete.}
6360 @section Derivations
6363 Low-level build actions and the environment in which they are performed
6364 are represented by @dfn{derivations}. A derivation contains the
6365 following pieces of information:
6369 The outputs of the derivation---derivations produce at least one file or
6370 directory in the store, but may produce more.
6373 @cindex build-time dependencies
6374 @cindex dependencies, build-time
6375 The inputs of the derivations---i.e., its build-time dependencies---which may
6376 be other derivations or plain files in the store (patches, build scripts,
6380 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
6383 The file name of a build script in the store, along with the arguments
6387 A list of environment variables to be defined.
6391 @cindex derivation path
6392 Derivations allow clients of the daemon to communicate build actions to
6393 the store. They exist in two forms: as an in-memory representation,
6394 both on the client- and daemon-side, and as files in the store whose
6395 name end in @code{.drv}---these files are referred to as @dfn{derivation
6396 paths}. Derivations paths can be passed to the @code{build-derivations}
6397 procedure to perform the build actions they prescribe (@pxref{The
6400 @cindex fixed-output derivations
6401 Operations such as file downloads and version-control checkouts for
6402 which the expected content hash is known in advance are modeled as
6403 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
6404 of a fixed-output derivation are independent of its inputs---e.g., a
6405 source code download produces the same result regardless of the download
6406 method and tools being used.
6409 @cindex run-time dependencies
6410 @cindex dependencies, run-time
6411 The outputs of derivations---i.e., the build results---have a set of
6412 @dfn{references}, as reported by the @code{references} RPC or the
6413 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
6414 are the set of run-time dependencies of the build results. References are a
6415 subset of the inputs of the derivation; this subset is automatically computed
6416 by the build daemon by scanning all the files in the outputs.
6418 The @code{(guix derivations)} module provides a representation of
6419 derivations as Scheme objects, along with procedures to create and
6420 otherwise manipulate derivations. The lowest-level primitive to create
6421 a derivation is the @code{derivation} procedure:
6423 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
6424 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
6425 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
6426 [#:system (%current-system)] [#:references-graphs #f] @
6427 [#:allowed-references #f] [#:disallowed-references #f] @
6428 [#:leaked-env-vars #f] [#:local-build? #f] @
6429 [#:substitutable? #t] [#:properties '()]
6430 Build a derivation with the given arguments, and return the resulting
6431 @code{<derivation>} object.
6433 When @var{hash} and @var{hash-algo} are given, a
6434 @dfn{fixed-output derivation} is created---i.e., one whose result is
6435 known in advance, such as a file download. If, in addition,
6436 @var{recursive?} is true, then that fixed output may be an executable
6437 file or a directory and @var{hash} must be the hash of an archive
6438 containing this output.
6440 When @var{references-graphs} is true, it must be a list of file
6441 name/store path pairs. In that case, the reference graph of each store
6442 path is exported in the build environment in the corresponding file, in
6443 a simple text format.
6445 When @var{allowed-references} is true, it must be a list of store items
6446 or outputs that the derivation's output may refer to. Likewise,
6447 @var{disallowed-references}, if true, must be a list of things the
6448 outputs may @emph{not} refer to.
6450 When @var{leaked-env-vars} is true, it must be a list of strings
6451 denoting environment variables that are allowed to ``leak'' from the
6452 daemon's environment to the build environment. This is only applicable
6453 to fixed-output derivations---i.e., when @var{hash} is true. The main
6454 use is to allow variables such as @code{http_proxy} to be passed to
6455 derivations that download files.
6457 When @var{local-build?} is true, declare that the derivation is not a
6458 good candidate for offloading and should rather be built locally
6459 (@pxref{Daemon Offload Setup}). This is the case for small derivations
6460 where the costs of data transfers would outweigh the benefits.
6462 When @var{substitutable?} is false, declare that substitutes of the
6463 derivation's output should not be used (@pxref{Substitutes}). This is
6464 useful, for instance, when building packages that capture details of the
6465 host CPU instruction set.
6467 @var{properties} must be an association list describing ``properties'' of the
6468 derivation. It is kept as-is, uninterpreted, in the derivation.
6472 Here's an example with a shell script as its builder, assuming
6473 @var{store} is an open connection to the daemon, and @var{bash} points
6474 to a Bash executable in the store:
6477 (use-modules (guix utils)
6481 (let ((builder ; add the Bash script to the store
6482 (add-text-to-store store "my-builder.sh"
6483 "echo hello world > $out\n" '())))
6484 (derivation store "foo"
6485 bash `("-e" ,builder)
6486 #:inputs `((,bash) (,builder))
6487 #:env-vars '(("HOME" . "/homeless"))))
6488 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
6491 As can be guessed, this primitive is cumbersome to use directly. A
6492 better approach is to write build scripts in Scheme, of course! The
6493 best course of action for that is to write the build code as a
6494 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
6495 information, @pxref{G-Expressions}.
6497 Once upon a time, @code{gexp->derivation} did not exist and constructing
6498 derivations with build code written in Scheme was achieved with
6499 @code{build-expression->derivation}, documented below. This procedure
6500 is now deprecated in favor of the much nicer @code{gexp->derivation}.
6502 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
6503 @var{name} @var{exp} @
6504 [#:system (%current-system)] [#:inputs '()] @
6505 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
6506 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
6507 [#:references-graphs #f] [#:allowed-references #f] @
6508 [#:disallowed-references #f] @
6509 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
6510 Return a derivation that executes Scheme expression @var{exp} as a
6511 builder for derivation @var{name}. @var{inputs} must be a list of
6512 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
6513 @code{"out"} is assumed. @var{modules} is a list of names of Guile
6514 modules from the current search path to be copied in the store,
6515 compiled, and made available in the load path during the execution of
6516 @var{exp}---e.g., @code{((guix build utils) (guix build
6517 gnu-build-system))}.
6519 @var{exp} is evaluated in an environment where @code{%outputs} is bound
6520 to a list of output/path pairs, and where @code{%build-inputs} is bound
6521 to a list of string/output-path pairs made from @var{inputs}.
6522 Optionally, @var{env-vars} is a list of string pairs specifying the name
6523 and value of environment variables visible to the builder. The builder
6524 terminates by passing the result of @var{exp} to @code{exit}; thus, when
6525 @var{exp} returns @code{#f}, the build is considered to have failed.
6527 @var{exp} is built using @var{guile-for-build} (a derivation). When
6528 @var{guile-for-build} is omitted or is @code{#f}, the value of the
6529 @code{%guile-for-build} fluid is used instead.
6531 See the @code{derivation} procedure for the meaning of
6532 @var{references-graphs}, @var{allowed-references},
6533 @var{disallowed-references}, @var{local-build?}, and
6534 @var{substitutable?}.
6538 Here's an example of a single-output derivation that creates a directory
6539 containing one file:
6542 (let ((builder '(let ((out (assoc-ref %outputs "out")))
6543 (mkdir out) ; create /gnu/store/@dots{}-goo
6544 (call-with-output-file (string-append out "/test")
6546 (display '(hello guix) p))))))
6547 (build-expression->derivation store "goo" builder))
6549 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
6553 @node The Store Monad
6554 @section The Store Monad
6558 The procedures that operate on the store described in the previous
6559 sections all take an open connection to the build daemon as their first
6560 argument. Although the underlying model is functional, they either have
6561 side effects or depend on the current state of the store.
6563 The former is inconvenient: the connection to the build daemon has to be
6564 carried around in all those functions, making it impossible to compose
6565 functions that do not take that parameter with functions that do. The
6566 latter can be problematic: since store operations have side effects
6567 and/or depend on external state, they have to be properly sequenced.
6569 @cindex monadic values
6570 @cindex monadic functions
6571 This is where the @code{(guix monads)} module comes in. This module
6572 provides a framework for working with @dfn{monads}, and a particularly
6573 useful monad for our uses, the @dfn{store monad}. Monads are a
6574 construct that allows two things: associating ``context'' with values
6575 (in our case, the context is the store), and building sequences of
6576 computations (here computations include accesses to the store). Values
6577 in a monad---values that carry this additional context---are called
6578 @dfn{monadic values}; procedures that return such values are called
6579 @dfn{monadic procedures}.
6581 Consider this ``normal'' procedure:
6584 (define (sh-symlink store)
6585 ;; Return a derivation that symlinks the 'bash' executable.
6586 (let* ((drv (package-derivation store bash))
6587 (out (derivation->output-path drv))
6588 (sh (string-append out "/bin/bash")))
6589 (build-expression->derivation store "sh"
6590 `(symlink ,sh %output))))
6593 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
6594 as a monadic function:
6597 (define (sh-symlink)
6598 ;; Same, but return a monadic value.
6599 (mlet %store-monad ((drv (package->derivation bash)))
6600 (gexp->derivation "sh"
6601 #~(symlink (string-append #$drv "/bin/bash")
6605 There are several things to note in the second version: the @code{store}
6606 parameter is now implicit and is ``threaded'' in the calls to the
6607 @code{package->derivation} and @code{gexp->derivation} monadic
6608 procedures, and the monadic value returned by @code{package->derivation}
6609 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
6611 As it turns out, the call to @code{package->derivation} can even be
6612 omitted since it will take place implicitly, as we will see later
6613 (@pxref{G-Expressions}):
6616 (define (sh-symlink)
6617 (gexp->derivation "sh"
6618 #~(symlink (string-append #$bash "/bin/bash")
6623 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
6624 @c for the funny quote.
6625 Calling the monadic @code{sh-symlink} has no effect. As someone once
6626 said, ``you exit a monad like you exit a building on fire: by running''.
6627 So, to exit the monad and get the desired effect, one must use
6628 @code{run-with-store}:
6631 (run-with-store (open-connection) (sh-symlink))
6632 @result{} /gnu/store/...-sh-symlink
6635 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
6636 new ``meta-commands'' to make it easier to deal with monadic procedures:
6637 @code{run-in-store}, and @code{enter-store-monad}. The former is used
6638 to ``run'' a single monadic value through the store:
6641 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
6642 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
6645 The latter enters a recursive REPL, where all the return values are
6646 automatically run through the store:
6649 scheme@@(guile-user)> ,enter-store-monad
6650 store-monad@@(guile-user) [1]> (package->derivation hello)
6651 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
6652 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
6653 $3 = "/gnu/store/@dots{}-foo"
6654 store-monad@@(guile-user) [1]> ,q
6655 scheme@@(guile-user)>
6659 Note that non-monadic values cannot be returned in the
6660 @code{store-monad} REPL.
6662 The main syntactic forms to deal with monads in general are provided by
6663 the @code{(guix monads)} module and are described below.
6665 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
6666 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
6670 @deffn {Scheme Syntax} return @var{val}
6671 Return a monadic value that encapsulates @var{val}.
6674 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
6675 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
6676 procedures @var{mproc}@dots{}@footnote{This operation is commonly
6677 referred to as ``bind'', but that name denotes an unrelated procedure in
6678 Guile. Thus we use this somewhat cryptic symbol inherited from the
6679 Haskell language.}. There can be one @var{mproc} or several of them, as
6684 (with-monad %state-monad
6686 (lambda (x) (return (+ 1 x)))
6687 (lambda (x) (return (* 2 x)))))
6691 @result{} some-state
6695 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
6697 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
6699 Bind the variables @var{var} to the monadic values @var{mval} in
6700 @var{body}, which is a sequence of expressions. As with the bind
6701 operator, this can be thought of as ``unpacking'' the raw, non-monadic
6702 value ``contained'' in @var{mval} and making @var{var} refer to that
6703 raw, non-monadic value within the scope of the @var{body}. The form
6704 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
6705 @var{val}, as per @code{let}. The binding operations occur in sequence
6706 from left to right. The last expression of @var{body} must be a monadic
6707 expression, and its result will become the result of the @code{mlet} or
6708 @code{mlet*} when run in the @var{monad}.
6710 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
6711 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
6714 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
6715 Bind @var{mexp} and the following monadic expressions in sequence,
6716 returning the result of the last expression. Every expression in the
6717 sequence must be a monadic expression.
6719 This is akin to @code{mlet}, except that the return values of the
6720 monadic expressions are ignored. In that sense, it is analogous to
6721 @code{begin}, but applied to monadic expressions.
6724 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
6725 When @var{condition} is true, evaluate the sequence of monadic
6726 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
6727 @var{condition} is false, return @code{*unspecified*} in the current
6728 monad. Every expression in the sequence must be a monadic expression.
6731 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
6732 When @var{condition} is false, evaluate the sequence of monadic
6733 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
6734 @var{condition} is true, return @code{*unspecified*} in the current
6735 monad. Every expression in the sequence must be a monadic expression.
6739 The @code{(guix monads)} module provides the @dfn{state monad}, which
6740 allows an additional value---the state---to be @emph{threaded} through
6741 monadic procedure calls.
6743 @defvr {Scheme Variable} %state-monad
6744 The state monad. Procedures in the state monad can access and change
6745 the state that is threaded.
6747 Consider the example below. The @code{square} procedure returns a value
6748 in the state monad. It returns the square of its argument, but also
6749 increments the current state value:
6753 (mlet %state-monad ((count (current-state)))
6754 (mbegin %state-monad
6755 (set-current-state (+ 1 count))
6758 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
6763 When ``run'' through @var{%state-monad}, we obtain that additional state
6764 value, which is the number of @code{square} calls.
6767 @deffn {Monadic Procedure} current-state
6768 Return the current state as a monadic value.
6771 @deffn {Monadic Procedure} set-current-state @var{value}
6772 Set the current state to @var{value} and return the previous state as a
6776 @deffn {Monadic Procedure} state-push @var{value}
6777 Push @var{value} to the current state, which is assumed to be a list,
6778 and return the previous state as a monadic value.
6781 @deffn {Monadic Procedure} state-pop
6782 Pop a value from the current state and return it as a monadic value.
6783 The state is assumed to be a list.
6786 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
6787 Run monadic value @var{mval} starting with @var{state} as the initial
6788 state. Return two values: the resulting value, and the resulting state.
6791 The main interface to the store monad, provided by the @code{(guix
6792 store)} module, is as follows.
6794 @defvr {Scheme Variable} %store-monad
6795 The store monad---an alias for @var{%state-monad}.
6797 Values in the store monad encapsulate accesses to the store. When its
6798 effect is needed, a value of the store monad must be ``evaluated'' by
6799 passing it to the @code{run-with-store} procedure (see below.)
6802 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
6803 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
6804 open store connection.
6807 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
6808 Return as a monadic value the absolute file name in the store of the file
6809 containing @var{text}, a string. @var{references} is a list of store items that the
6810 resulting text file refers to; it defaults to the empty list.
6813 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
6814 Return as a monadic value the absolute file name in the store of the file
6815 containing @var{data}, a bytevector. @var{references} is a list of store
6816 items that the resulting binary file refers to; it defaults to the empty list.
6819 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
6820 [#:recursive? #t] [#:select? (const #t)]
6821 Return the name of @var{file} once interned in the store. Use
6822 @var{name} as its store name, or the basename of @var{file} if
6823 @var{name} is omitted.
6825 When @var{recursive?} is true, the contents of @var{file} are added
6826 recursively; if @var{file} designates a flat file and @var{recursive?}
6827 is true, its contents are added, and its permission bits are kept.
6829 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
6830 @var{stat})} for each directory entry, where @var{file} is the entry's
6831 absolute file name and @var{stat} is the result of @code{lstat}; exclude
6832 entries for which @var{select?} does not return true.
6834 The example below adds a file to the store, under two different names:
6837 (run-with-store (open-connection)
6838 (mlet %store-monad ((a (interned-file "README"))
6839 (b (interned-file "README" "LEGU-MIN")))
6840 (return (list a b))))
6842 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
6847 The @code{(guix packages)} module exports the following package-related
6850 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
6851 [#:system (%current-system)] [#:target #f] @
6854 value in the absolute file name of @var{file} within the @var{output}
6855 directory of @var{package}. When @var{file} is omitted, return the name
6856 of the @var{output} directory of @var{package}. When @var{target} is
6857 true, use it as a cross-compilation target triplet.
6860 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
6861 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
6862 @var{target} [@var{system}]
6863 Monadic version of @code{package-derivation} and
6864 @code{package-cross-derivation} (@pxref{Defining Packages}).
6869 @section G-Expressions
6871 @cindex G-expression
6872 @cindex build code quoting
6873 So we have ``derivations'', which represent a sequence of build actions
6874 to be performed to produce an item in the store (@pxref{Derivations}).
6875 These build actions are performed when asking the daemon to actually
6876 build the derivations; they are run by the daemon in a container
6877 (@pxref{Invoking guix-daemon}).
6879 @cindex strata of code
6880 It should come as no surprise that we like to write these build actions
6881 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
6882 code@footnote{The term @dfn{stratum} in this context was coined by
6883 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
6884 Kiselyov, who has written insightful
6885 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
6886 on this topic}, refers to this kind of code generation as
6887 @dfn{staging}.}: the ``host code''---code that defines packages, talks
6888 to the daemon, etc.---and the ``build code''---code that actually
6889 performs build actions, such as making directories, invoking
6890 @command{make}, etc.
6892 To describe a derivation and its build actions, one typically needs to
6893 embed build code inside host code. It boils down to manipulating build
6894 code as data, and the homoiconicity of Scheme---code has a direct
6895 representation as data---comes in handy for that. But we need more than
6896 the normal @code{quasiquote} mechanism in Scheme to construct build
6899 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
6900 S-expressions adapted to build expressions. G-expressions, or
6901 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
6902 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
6903 @code{#$}, and @code{#$@@}), which are comparable to
6904 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
6905 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
6906 GNU Guile Reference Manual}). However, there are major differences:
6910 Gexps are meant to be written to a file and run or manipulated by other
6914 When a high-level object such as a package or derivation is unquoted
6915 inside a gexp, the result is as if its output file name had been
6919 Gexps carry information about the packages or derivations they refer to,
6920 and these dependencies are automatically added as inputs to the build
6921 processes that use them.
6924 @cindex lowering, of high-level objects in gexps
6925 This mechanism is not limited to package and derivation
6926 objects: @dfn{compilers} able to ``lower'' other high-level objects to
6927 derivations or files in the store can be defined,
6928 such that these objects can also be inserted
6929 into gexps. For example, a useful type of high-level objects that can be
6930 inserted in a gexp is ``file-like objects'', which make it easy to
6931 add files to the store and to refer to them in
6932 derivations and such (see @code{local-file} and @code{plain-file}
6935 To illustrate the idea, here is an example of a gexp:
6942 (symlink (string-append #$coreutils "/bin/ls")
6946 This gexp can be passed to @code{gexp->derivation}; we obtain a
6947 derivation that builds a directory containing exactly one symlink to
6948 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
6951 (gexp->derivation "the-thing" build-exp)
6954 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
6955 substituted to the reference to the @var{coreutils} package in the
6956 actual build code, and @var{coreutils} is automatically made an input to
6957 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
6958 output)}) is replaced by a string containing the directory name of the
6959 output of the derivation.
6961 @cindex cross compilation
6962 In a cross-compilation context, it is useful to distinguish between
6963 references to the @emph{native} build of a package---that can run on the
6964 host---versus references to cross builds of a package. To that end, the
6965 @code{#+} plays the same role as @code{#$}, but is a reference to a
6966 native package build:
6969 (gexp->derivation "vi"
6972 (system* (string-append #+coreutils "/bin/ln")
6974 (string-append #$emacs "/bin/emacs")
6975 (string-append #$output "/bin/vi")))
6976 #:target "mips64el-linux-gnu")
6980 In the example above, the native build of @var{coreutils} is used, so
6981 that @command{ln} can actually run on the host; but then the
6982 cross-compiled build of @var{emacs} is referenced.
6984 @cindex imported modules, for gexps
6985 @findex with-imported-modules
6986 Another gexp feature is @dfn{imported modules}: sometimes you want to be
6987 able to use certain Guile modules from the ``host environment'' in the
6988 gexp, so those modules should be imported in the ``build environment''.
6989 The @code{with-imported-modules} form allows you to express that:
6992 (let ((build (with-imported-modules '((guix build utils))
6994 (use-modules (guix build utils))
6995 (mkdir-p (string-append #$output "/bin"))))))
6996 (gexp->derivation "empty-dir"
6999 (display "success!\n")
7004 In this example, the @code{(guix build utils)} module is automatically
7005 pulled into the isolated build environment of our gexp, such that
7006 @code{(use-modules (guix build utils))} works as expected.
7008 @cindex module closure
7009 @findex source-module-closure
7010 Usually you want the @emph{closure} of the module to be imported---i.e.,
7011 the module itself and all the modules it depends on---rather than just
7012 the module; failing to do that, attempts to use the module will fail
7013 because of missing dependent modules. The @code{source-module-closure}
7014 procedure computes the closure of a module by looking at its source file
7015 headers, which comes in handy in this case:
7018 (use-modules (guix modules)) ;for 'source-module-closure'
7020 (with-imported-modules (source-module-closure
7021 '((guix build utils)
7023 (gexp->derivation "something-with-vms"
7025 (use-modules (guix build utils)
7030 @cindex extensions, for gexps
7031 @findex with-extensions
7032 In the same vein, sometimes you want to import not just pure-Scheme
7033 modules, but also ``extensions'' such as Guile bindings to C libraries
7034 or other ``full-blown'' packages. Say you need the @code{guile-json}
7035 package available on the build side, here's how you would do it:
7038 (use-modules (gnu packages guile)) ;for 'guile-json'
7040 (with-extensions (list guile-json)
7041 (gexp->derivation "something-with-json"
7043 (use-modules (json))
7047 The syntactic form to construct gexps is summarized below.
7049 @deffn {Scheme Syntax} #~@var{exp}
7050 @deffnx {Scheme Syntax} (gexp @var{exp})
7051 Return a G-expression containing @var{exp}. @var{exp} may contain one
7052 or more of the following forms:
7056 @itemx (ungexp @var{obj})
7057 Introduce a reference to @var{obj}. @var{obj} may have one of the
7058 supported types, for example a package or a
7059 derivation, in which case the @code{ungexp} form is replaced by its
7060 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
7062 If @var{obj} is a list, it is traversed and references to supported
7063 objects are substituted similarly.
7065 If @var{obj} is another gexp, its contents are inserted and its
7066 dependencies are added to those of the containing gexp.
7068 If @var{obj} is another kind of object, it is inserted as is.
7070 @item #$@var{obj}:@var{output}
7071 @itemx (ungexp @var{obj} @var{output})
7072 This is like the form above, but referring explicitly to the
7073 @var{output} of @var{obj}---this is useful when @var{obj} produces
7074 multiple outputs (@pxref{Packages with Multiple Outputs}).
7077 @itemx #+@var{obj}:output
7078 @itemx (ungexp-native @var{obj})
7079 @itemx (ungexp-native @var{obj} @var{output})
7080 Same as @code{ungexp}, but produces a reference to the @emph{native}
7081 build of @var{obj} when used in a cross compilation context.
7083 @item #$output[:@var{output}]
7084 @itemx (ungexp output [@var{output}])
7085 Insert a reference to derivation output @var{output}, or to the main
7086 output when @var{output} is omitted.
7088 This only makes sense for gexps passed to @code{gexp->derivation}.
7091 @itemx (ungexp-splicing @var{lst})
7092 Like the above, but splices the contents of @var{lst} inside the
7096 @itemx (ungexp-native-splicing @var{lst})
7097 Like the above, but refers to native builds of the objects listed in
7102 G-expressions created by @code{gexp} or @code{#~} are run-time objects
7103 of the @code{gexp?} type (see below.)
7106 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
7107 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
7108 in their execution environment.
7110 Each item in @var{modules} can be the name of a module, such as
7111 @code{(guix build utils)}, or it can be a module name, followed by an
7112 arrow, followed by a file-like object:
7115 `((guix build utils)
7117 ((guix config) => ,(scheme-file "config.scm"
7118 #~(define-module @dots{}))))
7122 In the example above, the first two modules are taken from the search
7123 path, and the last one is created from the given file-like object.
7125 This form has @emph{lexical} scope: it has an effect on the gexps
7126 directly defined in @var{body}@dots{}, but not on those defined, say, in
7127 procedures called from @var{body}@dots{}.
7130 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
7131 Mark the gexps defined in @var{body}@dots{} as requiring
7132 @var{extensions} in their build and execution environment.
7133 @var{extensions} is typically a list of package objects such as those
7134 defined in the @code{(gnu packages guile)} module.
7136 Concretely, the packages listed in @var{extensions} are added to the
7137 load path while compiling imported modules in @var{body}@dots{}; they
7138 are also added to the load path of the gexp returned by
7142 @deffn {Scheme Procedure} gexp? @var{obj}
7143 Return @code{#t} if @var{obj} is a G-expression.
7146 G-expressions are meant to be written to disk, either as code building
7147 some derivation, or as plain files in the store. The monadic procedures
7148 below allow you to do that (@pxref{The Store Monad}, for more
7149 information about monads.)
7151 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
7152 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
7153 [#:hash #f] [#:hash-algo #f] @
7154 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7155 [#:module-path @var{%load-path}] @
7156 [#:effective-version "2.2"] @
7157 [#:references-graphs #f] [#:allowed-references #f] @
7158 [#:disallowed-references #f] @
7159 [#:leaked-env-vars #f] @
7160 [#:script-name (string-append @var{name} "-builder")] @
7161 [#:deprecation-warnings #f] @
7162 [#:local-build? #f] [#:substitutable? #t] @
7163 [#:properties '()] [#:guile-for-build #f]
7164 Return a derivation @var{name} that runs @var{exp} (a gexp) with
7165 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
7166 stored in a file called @var{script-name}. When @var{target} is true,
7167 it is used as the cross-compilation target triplet for packages referred
7170 @var{modules} is deprecated in favor of @code{with-imported-modules}.
7172 make @var{modules} available in the evaluation context of @var{exp};
7173 @var{modules} is a list of names of Guile modules searched in
7174 @var{module-path} to be copied in the store, compiled, and made available in
7175 the load path during the execution of @var{exp}---e.g., @code{((guix
7176 build utils) (guix build gnu-build-system))}.
7178 @var{effective-version} determines the string to use when adding extensions of
7179 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
7181 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
7184 When @var{references-graphs} is true, it must be a list of tuples of one of the
7188 (@var{file-name} @var{package})
7189 (@var{file-name} @var{package} @var{output})
7190 (@var{file-name} @var{derivation})
7191 (@var{file-name} @var{derivation} @var{output})
7192 (@var{file-name} @var{store-item})
7195 The right-hand-side of each element of @var{references-graphs} is automatically made
7196 an input of the build process of @var{exp}. In the build environment, each
7197 @var{file-name} contains the reference graph of the corresponding item, in a simple
7200 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
7201 In the latter case, the list denotes store items that the result is allowed to
7202 refer to. Any reference to another store item will lead to a build error.
7203 Similarly for @var{disallowed-references}, which can list items that must not be
7204 referenced by the outputs.
7206 @var{deprecation-warnings} determines whether to show deprecation warnings while
7207 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
7209 The other arguments are as for @code{derivation} (@pxref{Derivations}).
7212 @cindex file-like objects
7213 The @code{local-file}, @code{plain-file}, @code{computed-file},
7214 @code{program-file}, and @code{scheme-file} procedures below return
7215 @dfn{file-like objects}. That is, when unquoted in a G-expression,
7216 these objects lead to a file in the store. Consider this G-expression:
7219 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
7220 #$(local-file "/tmp/my-nscd.conf"))
7223 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
7224 to the store. Once expanded, for instance @i{via}
7225 @code{gexp->derivation}, the G-expression refers to that copy under
7226 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
7227 does not have any effect on what the G-expression does.
7228 @code{plain-file} can be used similarly; it differs in that the file
7229 content is directly passed as a string.
7231 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
7232 [#:recursive? #f] [#:select? (const #t)]
7233 Return an object representing local file @var{file} to add to the store; this
7234 object can be used in a gexp. If @var{file} is a relative file name, it is looked
7235 up relative to the source file where this form appears. @var{file} will be added to
7236 the store under @var{name}--by default the base name of @var{file}.
7238 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
7239 designates a flat file and @var{recursive?} is true, its contents are added, and its
7240 permission bits are kept.
7242 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7243 @var{stat})} for each directory entry, where @var{file} is the entry's
7244 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7245 entries for which @var{select?} does not return true.
7247 This is the declarative counterpart of the @code{interned-file} monadic
7248 procedure (@pxref{The Store Monad, @code{interned-file}}).
7251 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
7252 Return an object representing a text file called @var{name} with the given
7253 @var{content} (a string or a bytevector) to be added to the store.
7255 This is the declarative counterpart of @code{text-file}.
7258 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
7259 [#:options '(#:local-build? #t)]
7260 Return an object representing the store item @var{name}, a file or
7261 directory computed by @var{gexp}. @var{options}
7262 is a list of additional arguments to pass to @code{gexp->derivation}.
7264 This is the declarative counterpart of @code{gexp->derivation}.
7267 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
7268 [#:guile (default-guile)] [#:module-path %load-path]
7269 Return an executable script @var{name} that runs @var{exp} using
7270 @var{guile}, with @var{exp}'s imported modules in its search path.
7271 Look up @var{exp}'s modules in @var{module-path}.
7273 The example below builds a script that simply invokes the @command{ls}
7277 (use-modules (guix gexp) (gnu packages base))
7279 (gexp->script "list-files"
7280 #~(execl #$(file-append coreutils "/bin/ls")
7284 When ``running'' it through the store (@pxref{The Store Monad,
7285 @code{run-with-store}}), we obtain a derivation that produces an
7286 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
7289 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
7291 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
7295 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
7296 [#:guile #f] [#:module-path %load-path]
7297 Return an object representing the executable store item @var{name} that
7298 runs @var{gexp}. @var{guile} is the Guile package used to execute that
7299 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
7301 This is the declarative counterpart of @code{gexp->script}.
7304 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
7305 [#:set-load-path? #t] [#:module-path %load-path] @
7307 [#:guile (default-guile)]
7308 Return a derivation that builds a file @var{name} containing @var{exp}.
7309 When @var{splice?} is true, @var{exp} is considered to be a list of
7310 expressions that will be spliced in the resulting file.
7312 When @var{set-load-path?} is true, emit code in the resulting file to
7313 set @code{%load-path} and @code{%load-compiled-path} to honor
7314 @var{exp}'s imported modules. Look up @var{exp}'s modules in
7317 The resulting file holds references to all the dependencies of @var{exp}
7318 or a subset thereof.
7321 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} [#:splice? #f]
7322 Return an object representing the Scheme file @var{name} that contains
7325 This is the declarative counterpart of @code{gexp->file}.
7328 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
7329 Return as a monadic value a derivation that builds a text file
7330 containing all of @var{text}. @var{text} may list, in addition to
7331 strings, objects of any type that can be used in a gexp: packages,
7332 derivations, local file objects, etc. The resulting store file holds
7333 references to all these.
7335 This variant should be preferred over @code{text-file} anytime the file
7336 to create will reference items from the store. This is typically the
7337 case when building a configuration file that embeds store file names,
7341 (define (profile.sh)
7342 ;; Return the name of a shell script in the store that
7343 ;; initializes the 'PATH' environment variable.
7344 (text-file* "profile.sh"
7345 "export PATH=" coreutils "/bin:"
7346 grep "/bin:" sed "/bin\n"))
7349 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
7350 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
7351 preventing them from being garbage-collected during its lifetime.
7354 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
7355 Return an object representing store file @var{name} containing
7356 @var{text}. @var{text} is a sequence of strings and file-like objects,
7360 (mixed-text-file "profile"
7361 "export PATH=" coreutils "/bin:" grep "/bin")
7364 This is the declarative counterpart of @code{text-file*}.
7367 @deffn {Scheme Procedure} file-union @var{name} @var{files}
7368 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
7369 Each item in @var{files} must be a two-element list where the first element is the
7370 file name to use in the new directory, and the second element is a gexp
7371 denoting the target file. Here's an example:
7375 `(("hosts" ,(plain-file "hosts"
7376 "127.0.0.1 localhost"))
7377 ("bashrc" ,(plain-file "bashrc"
7378 "alias ls='ls --color=auto'"))))
7381 This yields an @code{etc} directory containing these two files.
7384 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
7385 Return a directory that is the union of @var{things}, where @var{things} is a list of
7386 file-like objects denoting directories. For example:
7389 (directory-union "guile+emacs" (list guile emacs))
7392 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
7395 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
7396 Return a file-like object that expands to the concatenation of @var{obj}
7397 and @var{suffix}, where @var{obj} is a lowerable object and each
7398 @var{suffix} is a string.
7400 As an example, consider this gexp:
7403 (gexp->script "run-uname"
7404 #~(system* #$(file-append coreutils
7408 The same effect could be achieved with:
7411 (gexp->script "run-uname"
7412 #~(system* (string-append #$coreutils
7416 There is one difference though: in the @code{file-append} case, the
7417 resulting script contains the absolute file name as a string, whereas in
7418 the second case, the resulting script contains a @code{(string-append
7419 @dots{})} expression to construct the file name @emph{at run time}.
7423 Of course, in addition to gexps embedded in ``host'' code, there are
7424 also modules containing build tools. To make it clear that they are
7425 meant to be used in the build stratum, these modules are kept in the
7426 @code{(guix build @dots{})} name space.
7428 @cindex lowering, of high-level objects in gexps
7429 Internally, high-level objects are @dfn{lowered}, using their compiler,
7430 to either derivations or store items. For instance, lowering a package
7431 yields a derivation, and lowering a @code{plain-file} yields a store
7432 item. This is achieved using the @code{lower-object} monadic procedure.
7434 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
7436 Return as a value in @var{%store-monad} the derivation or store item
7437 corresponding to @var{obj} for @var{system}, cross-compiling for
7438 @var{target} if @var{target} is true. @var{obj} must be an object that
7439 has an associated gexp compiler, such as a @code{<package>}.
7442 @node Invoking guix repl
7443 @section Invoking @command{guix repl}
7445 @cindex REPL, read-eval-print loop
7446 The @command{guix repl} command spawns a Guile @dfn{read-eval-print loop}
7447 (REPL) for interactive programming (@pxref{Using Guile Interactively,,, guile,
7448 GNU Guile Reference Manual}). Compared to just launching the @command{guile}
7449 command, @command{guix repl} guarantees that all the Guix modules and all its
7450 dependencies are available in the search path. You can use it this way:
7454 scheme@@(guile-user)> ,use (gnu packages base)
7455 scheme@@(guile-user)> coreutils
7456 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
7460 In addition, @command{guix repl} implements a simple machine-readable REPL
7461 protocol for use by @code{(guix inferior)}, a facility to interact with
7462 @dfn{inferiors}, separate processes running a potentially different revision
7465 The available options are as follows:
7468 @item --type=@var{type}
7469 @itemx -t @var{type}
7470 Start a REPL of the given @var{TYPE}, which can be one of the following:
7474 This is default, and it spawns a standard full-featured Guile REPL.
7476 Spawn a REPL that uses the machine-readable protocol. This is the protocol
7477 that the @code{(guix inferior)} module speaks.
7480 @item --listen=@var{endpoint}
7481 By default, @command{guix repl} reads from standard input and writes to
7482 standard output. When this option is passed, it will instead listen for
7483 connections on @var{endpoint}. Here are examples of valid options:
7486 @item --listen=tcp:37146
7487 Accept connections on localhost on port 37146.
7489 @item --listen=unix:/tmp/socket
7490 Accept connections on the Unix-domain socket @file{/tmp/socket}.
7494 @c *********************************************************************
7498 This section describes Guix command-line utilities. Some of them are
7499 primarily targeted at developers and users who write new package
7500 definitions, while others are more generally useful. They complement
7501 the Scheme programming interface of Guix in a convenient way.
7504 * Invoking guix build:: Building packages from the command line.
7505 * Invoking guix edit:: Editing package definitions.
7506 * Invoking guix download:: Downloading a file and printing its hash.
7507 * Invoking guix hash:: Computing the cryptographic hash of a file.
7508 * Invoking guix import:: Importing package definitions.
7509 * Invoking guix refresh:: Updating package definitions.
7510 * Invoking guix lint:: Finding errors in package definitions.
7511 * Invoking guix size:: Profiling disk usage.
7512 * Invoking guix graph:: Visualizing the graph of packages.
7513 * Invoking guix publish:: Sharing substitutes.
7514 * Invoking guix challenge:: Challenging substitute servers.
7515 * Invoking guix copy:: Copying to and from a remote store.
7516 * Invoking guix container:: Process isolation.
7517 * Invoking guix weather:: Assessing substitute availability.
7518 * Invoking guix processes:: Listing client processes.
7521 @node Invoking guix build
7522 @section Invoking @command{guix build}
7524 @cindex package building
7525 @cindex @command{guix build}
7526 The @command{guix build} command builds packages or derivations and
7527 their dependencies, and prints the resulting store paths. Note that it
7528 does not modify the user's profile---this is the job of the
7529 @command{guix package} command (@pxref{Invoking guix package}). Thus,
7530 it is mainly useful for distribution developers.
7532 The general syntax is:
7535 guix build @var{options} @var{package-or-derivation}@dots{}
7538 As an example, the following command builds the latest versions of Emacs
7539 and of Guile, displays their build logs, and finally displays the
7540 resulting directories:
7543 guix build emacs guile
7546 Similarly, the following command builds all the available packages:
7549 guix build --quiet --keep-going \
7550 `guix package -A | cut -f1,2 --output-delimiter=@@`
7553 @var{package-or-derivation} may be either the name of a package found in
7554 the software distribution such as @code{coreutils} or
7555 @code{coreutils@@8.20}, or a derivation such as
7556 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
7557 package with the corresponding name (and optionally version) is searched
7558 for among the GNU distribution modules (@pxref{Package Modules}).
7560 Alternatively, the @code{--expression} option may be used to specify a
7561 Scheme expression that evaluates to a package; this is useful when
7562 disambiguating among several same-named packages or package variants is
7565 There may be zero or more @var{options}. The available options are
7566 described in the subsections below.
7569 * Common Build Options:: Build options for most commands.
7570 * Package Transformation Options:: Creating variants of packages.
7571 * Additional Build Options:: Options specific to 'guix build'.
7572 * Debugging Build Failures:: Real life packaging experience.
7575 @node Common Build Options
7576 @subsection Common Build Options
7578 A number of options that control the build process are common to
7579 @command{guix build} and other commands that can spawn builds, such as
7580 @command{guix package} or @command{guix archive}. These are the
7585 @item --load-path=@var{directory}
7586 @itemx -L @var{directory}
7587 Add @var{directory} to the front of the package module search path
7588 (@pxref{Package Modules}).
7590 This allows users to define their own packages and make them visible to
7591 the command-line tools.
7595 Keep the build tree of failed builds. Thus, if a build fails, its build
7596 tree is kept under @file{/tmp}, in a directory whose name is shown at
7597 the end of the build log. This is useful when debugging build issues.
7598 @xref{Debugging Build Failures}, for tips and tricks on how to debug
7601 This option has no effect when connecting to a remote daemon with a
7602 @code{guix://} URI (@pxref{The Store, the @code{GUIX_DAEMON_SOCKET}
7607 Keep going when some of the derivations fail to build; return only once
7608 all the builds have either completed or failed.
7610 The default behavior is to stop as soon as one of the specified
7611 derivations has failed.
7615 Do not build the derivations.
7617 @anchor{fallback-option}
7619 When substituting a pre-built binary fails, fall back to building
7620 packages locally (@pxref{Substitution Failure}).
7622 @item --substitute-urls=@var{urls}
7623 @anchor{client-substitute-urls}
7624 Consider @var{urls} the whitespace-separated list of substitute source
7625 URLs, overriding the default list of URLs of @command{guix-daemon}
7626 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
7628 This means that substitutes may be downloaded from @var{urls}, provided
7629 they are signed by a key authorized by the system administrator
7630 (@pxref{Substitutes}).
7632 When @var{urls} is the empty string, substitutes are effectively
7635 @item --no-substitutes
7636 Do not use substitutes for build products. That is, always build things
7637 locally instead of allowing downloads of pre-built binaries
7638 (@pxref{Substitutes}).
7641 Do not ``graft'' packages. In practice, this means that package updates
7642 available as grafts are not applied. @xref{Security Updates}, for more
7643 information on grafts.
7645 @item --rounds=@var{n}
7646 Build each derivation @var{n} times in a row, and raise an error if
7647 consecutive build results are not bit-for-bit identical.
7649 This is a useful way to detect non-deterministic builds processes.
7650 Non-deterministic build processes are a problem because they make it
7651 practically impossible for users to @emph{verify} whether third-party
7652 binaries are genuine. @xref{Invoking guix challenge}, for more.
7654 Note that, currently, the differing build results are not kept around,
7655 so you will have to manually investigate in case of an error---e.g., by
7656 stashing one of the build results with @code{guix archive --export}
7657 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
7660 @item --no-build-hook
7661 Do not attempt to offload builds @i{via} the ``build hook'' of the daemon
7662 (@pxref{Daemon Offload Setup}). That is, always build things locally
7663 instead of offloading builds to remote machines.
7665 @item --max-silent-time=@var{seconds}
7666 When the build or substitution process remains silent for more than
7667 @var{seconds}, terminate it and report a build failure.
7669 By default, the daemon's setting is honored (@pxref{Invoking
7670 guix-daemon, @code{--max-silent-time}}).
7672 @item --timeout=@var{seconds}
7673 Likewise, when the build or substitution process lasts for more than
7674 @var{seconds}, terminate it and report a build failure.
7676 By default, the daemon's setting is honored (@pxref{Invoking
7677 guix-daemon, @code{--timeout}}).
7679 @c Note: This option is actually not part of %standard-build-options but
7680 @c most programs honor it.
7681 @cindex verbosity, of the command-line tools
7682 @cindex build logs, verbosity
7683 @item -v @var{level}
7684 @itemx --verbosity=@var{level}
7685 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
7686 output is produced, 1 is for quiet output, and 2 shows all the build log
7687 output on standard error.
7689 @item --cores=@var{n}
7691 Allow the use of up to @var{n} CPU cores for the build. The special
7692 value @code{0} means to use as many CPU cores as available.
7694 @item --max-jobs=@var{n}
7696 Allow at most @var{n} build jobs in parallel. @xref{Invoking
7697 guix-daemon, @code{--max-jobs}}, for details about this option and the
7698 equivalent @command{guix-daemon} option.
7700 @item --debug=@var{level}
7701 Produce debugging output coming from the build daemon. @var{level} must be an
7702 integer between 0 and 5; higher means more verbose output. Setting a level of
7703 4 or more may be helpful when debugging setup issues with the build daemon.
7707 Behind the scenes, @command{guix build} is essentially an interface to
7708 the @code{package-derivation} procedure of the @code{(guix packages)}
7709 module, and to the @code{build-derivations} procedure of the @code{(guix
7710 derivations)} module.
7712 In addition to options explicitly passed on the command line,
7713 @command{guix build} and other @command{guix} commands that support
7714 building honor the @code{GUIX_BUILD_OPTIONS} environment variable.
7716 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
7717 Users can define this variable to a list of command line options that
7718 will automatically be used by @command{guix build} and other
7719 @command{guix} commands that can perform builds, as in the example
7723 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
7726 These options are parsed independently, and the result is appended to
7727 the parsed command-line options.
7731 @node Package Transformation Options
7732 @subsection Package Transformation Options
7734 @cindex package variants
7735 Another set of command-line options supported by @command{guix build}
7736 and also @command{guix package} are @dfn{package transformation
7737 options}. These are options that make it possible to define @dfn{package
7738 variants}---for instance, packages built from different source code.
7739 This is a convenient way to create customized packages on the fly
7740 without having to type in the definitions of package variants
7741 (@pxref{Defining Packages}).
7745 @item --with-source=@var{source}
7746 @itemx --with-source=@var{package}=@var{source}
7747 @itemx --with-source=@var{package}@@@var{version}=@var{source}
7748 Use @var{source} as the source of @var{package}, and @var{version} as
7750 @var{source} must be a file name or a URL, as for @command{guix
7751 download} (@pxref{Invoking guix download}).
7753 When @var{package} is omitted,
7754 it is taken to be the package name specified on the
7755 command line that matches the base of @var{source}---e.g.,
7756 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
7757 package is @code{guile}.
7759 Likewise, when @var{version} is omitted, the version string is inferred from
7760 @var{source}; in the previous example, it is @code{2.0.10}.
7762 This option allows users to try out versions of packages other than the
7763 one provided by the distribution. The example below downloads
7764 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
7765 the @code{ed} package:
7768 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
7771 As a developer, @code{--with-source} makes it easy to test release
7775 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
7778 @dots{} or to build from a checkout in a pristine environment:
7781 $ git clone git://git.sv.gnu.org/guix.git
7782 $ guix build guix --with-source=guix@@1.0=./guix
7785 @item --with-input=@var{package}=@var{replacement}
7786 Replace dependency on @var{package} by a dependency on
7787 @var{replacement}. @var{package} must be a package name, and
7788 @var{replacement} must be a package specification such as @code{guile}
7789 or @code{guile@@1.8}.
7791 For instance, the following command builds Guix, but replaces its
7792 dependency on the current stable version of Guile with a dependency on
7793 the legacy version of Guile, @code{guile@@2.0}:
7796 guix build --with-input=guile=guile@@2.0 guix
7799 This is a recursive, deep replacement. So in this example, both
7800 @code{guix} and its dependency @code{guile-json} (which also depends on
7801 @code{guile}) get rebuilt against @code{guile@@2.0}.
7803 This is implemented using the @code{package-input-rewriting} Scheme
7804 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
7806 @item --with-graft=@var{package}=@var{replacement}
7807 This is similar to @code{--with-input} but with an important difference:
7808 instead of rebuilding the whole dependency chain, @var{replacement} is
7809 built and then @dfn{grafted} onto the binaries that were initially
7810 referring to @var{package}. @xref{Security Updates}, for more
7811 information on grafts.
7813 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
7814 and all its dependencies, replacing references to the version of GnuTLS
7815 they currently refer to:
7818 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
7821 This has the advantage of being much faster than rebuilding everything.
7822 But there is a caveat: it works if and only if @var{package} and
7823 @var{replacement} are strictly compatible---for example, if they provide
7824 a library, the application binary interface (ABI) of those libraries
7825 must be compatible. If @var{replacement} is somehow incompatible with
7826 @var{package}, then the resulting package may be unusable. Use with
7829 @item --with-git-url=@var{package}=@var{url}
7830 @cindex Git, using the latest commit
7831 @cindex latest commit, building
7832 Build @var{package} from the latest commit of the @code{master} branch of the
7833 Git repository at @var{url}. Git sub-modules of the repository are fetched,
7836 For example, the following command builds the NumPy Python library against the
7837 latest commit of the master branch of Python itself:
7840 guix build python-numpy \
7841 --with-git-url=python=https://github.com/python/cpython
7844 This option can also be combined with @code{--with-branch} or
7845 @code{--with-commit} (see below).
7847 @cindex continuous integration
7848 Obviously, since it uses the latest commit of the given branch, the result of
7849 such a command varies over time. Nevertheless it is a convenient way to
7850 rebuild entire software stacks against the latest commit of one or more
7851 packages. This is particularly useful in the context of continuous
7854 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
7855 consecutive accesses to the same repository. You may want to clean it up once
7856 in a while to save disk space.
7858 @item --with-branch=@var{package}=@var{branch}
7859 Build @var{package} from the latest commit of @var{branch}. If the
7860 @code{source} field of @var{package} is an origin with the @code{git-fetch}
7861 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
7862 repository URL is taken from that @code{source}. Otherwise you have to use
7863 @code{--with-git-url} to specify the URL of the Git repository.
7865 For instance, the following command builds @code{guile-sqlite3} from the
7866 latest commit of its @code{master} branch, and then builds @code{guix} (which
7867 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
7868 specific @code{guile-sqlite3} build:
7871 guix build --with-branch=guile-sqlite3=master cuirass
7874 @item --with-commit=@var{package}=@var{commit}
7875 This is similar to @code{--with-branch}, except that it builds from
7876 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
7877 Git commit SHA1 identifier.
7880 @node Additional Build Options
7881 @subsection Additional Build Options
7883 The command-line options presented below are specific to @command{guix
7890 Build quietly, without displaying the build log; this is equivalent to
7891 @code{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
7892 (or similar) and can always be retrieved using the @option{--log-file} option.
7894 @item --file=@var{file}
7895 @itemx -f @var{file}
7896 Build the package, derivation, or other file-like object that the code within
7897 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
7899 As an example, @var{file} might contain a package definition like this
7900 (@pxref{Defining Packages}):
7903 @verbatiminclude package-hello.scm
7906 @item --expression=@var{expr}
7907 @itemx -e @var{expr}
7908 Build the package or derivation @var{expr} evaluates to.
7910 For example, @var{expr} may be @code{(@@ (gnu packages guile)
7911 guile-1.8)}, which unambiguously designates this specific variant of
7912 version 1.8 of Guile.
7914 Alternatively, @var{expr} may be a G-expression, in which case it is used
7915 as a build program passed to @code{gexp->derivation}
7916 (@pxref{G-Expressions}).
7918 Lastly, @var{expr} may refer to a zero-argument monadic procedure
7919 (@pxref{The Store Monad}). The procedure must return a derivation as a
7920 monadic value, which is then passed through @code{run-with-store}.
7924 Build the source derivations of the packages, rather than the packages
7927 For instance, @code{guix build -S gcc} returns something like
7928 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
7931 The returned source tarball is the result of applying any patches and
7932 code snippets specified in the package @code{origin} (@pxref{Defining
7936 Fetch and return the source of @var{package-or-derivation} and all their
7937 dependencies, recursively. This is a handy way to obtain a local copy
7938 of all the source code needed to build @var{packages}, allowing you to
7939 eventually build them even without network access. It is an extension
7940 of the @code{--source} option and can accept one of the following
7941 optional argument values:
7945 This value causes the @code{--sources} option to behave in the same way
7946 as the @code{--source} option.
7949 Build the source derivations of all packages, including any source that
7950 might be listed as @code{inputs}. This is the default value.
7953 $ guix build --sources tzdata
7954 The following derivations will be built:
7955 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
7956 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
7960 Build the source derivations of all packages, as well of all transitive
7961 inputs to the packages. This can be used e.g.@: to
7962 prefetch package source for later offline building.
7965 $ guix build --sources=transitive tzdata
7966 The following derivations will be built:
7967 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
7968 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
7969 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
7970 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
7971 /gnu/store/@dots{}-make-4.1.tar.xz.drv
7972 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
7978 @item --system=@var{system}
7979 @itemx -s @var{system}
7980 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
7981 the system type of the build host.
7984 The @code{--system} flag is for @emph{native} compilation and must not
7985 be confused with cross-compilation. See @code{--target} below for
7986 information on cross-compilation.
7989 An example use of this is on Linux-based systems, which can emulate
7990 different personalities. For instance, passing
7991 @code{--system=i686-linux} on an @code{x86_64-linux} system or
7992 @code{--system=armhf-linux} on an @code{aarch64-linux} system allows you
7993 to build packages in a complete 32-bit environment.
7996 Building for an @code{armhf-linux} system is unconditionally enabled on
7997 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
7998 allow for this functionality, notably the ThunderX.
8001 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
8002 is enabled (@pxref{Virtualization Services,
8003 @code{qemu-binfmt-service-type}}), you can build for any system for
8004 which a QEMU @code{binfmt_misc} handler is installed.
8006 Builds for a system other than that of the machine you are using can
8007 also be offloaded to a remote machine of the right architecture.
8008 @xref{Daemon Offload Setup}, for more information on offloading.
8010 @item --target=@var{triplet}
8011 @cindex cross-compilation
8012 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
8013 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
8014 configuration triplets,, autoconf, Autoconf}).
8016 @anchor{build-check}
8018 @cindex determinism, checking
8019 @cindex reproducibility, checking
8020 Rebuild @var{package-or-derivation}, which are already available in the
8021 store, and raise an error if the build results are not bit-for-bit
8024 This mechanism allows you to check whether previously installed
8025 substitutes are genuine (@pxref{Substitutes}), or whether the build result
8026 of a package is deterministic. @xref{Invoking guix challenge}, for more
8027 background information and tools.
8029 When used in conjunction with @option{--keep-failed}, the differing
8030 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
8031 This makes it easy to look for differences between the two results.
8034 @cindex repairing store items
8035 @cindex corruption, recovering from
8036 Attempt to repair the specified store items, if they are corrupt, by
8037 re-downloading or rebuilding them.
8039 This operation is not atomic and thus restricted to @code{root}.
8043 Return the derivation paths, not the output paths, of the given
8046 @item --root=@var{file}
8047 @itemx -r @var{file}
8048 @cindex GC roots, adding
8049 @cindex garbage collector roots, adding
8050 Make @var{file} a symlink to the result, and register it as a garbage
8053 Consequently, the results of this @command{guix build} invocation are
8054 protected from garbage collection until @var{file} is removed. When
8055 that option is omitted, build results are eligible for garbage
8056 collection as soon as the build completes. @xref{Invoking guix gc}, for
8060 @cindex build logs, access
8061 Return the build log file names or URLs for the given
8062 @var{package-or-derivation}, or raise an error if build logs are
8065 This works regardless of how packages or derivations are specified. For
8066 instance, the following invocations are equivalent:
8069 guix build --log-file `guix build -d guile`
8070 guix build --log-file `guix build guile`
8071 guix build --log-file guile
8072 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
8075 If a log is unavailable locally, and unless @code{--no-substitutes} is
8076 passed, the command looks for a corresponding log on one of the
8077 substitute servers (as specified with @code{--substitute-urls}.)
8079 So for instance, imagine you want to see the build log of GDB on MIPS,
8080 but you are actually on an @code{x86_64} machine:
8083 $ guix build --log-file gdb -s mips64el-linux
8084 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
8087 You can freely access a huge library of build logs!
8090 @node Debugging Build Failures
8091 @subsection Debugging Build Failures
8093 @cindex build failures, debugging
8094 When defining a new package (@pxref{Defining Packages}), you will
8095 probably find yourself spending some time debugging and tweaking the
8096 build until it succeeds. To do that, you need to operate the build
8097 commands yourself in an environment as close as possible to the one the
8100 To that end, the first thing to do is to use the @option{--keep-failed}
8101 or @option{-K} option of @command{guix build}, which will keep the
8102 failed build tree in @file{/tmp} or whatever directory you specified as
8103 @code{TMPDIR} (@pxref{Invoking guix build, @code{--keep-failed}}).
8105 From there on, you can @command{cd} to the failed build tree and source
8106 the @file{environment-variables} file, which contains all the
8107 environment variable definitions that were in place when the build
8108 failed. So let's say you're debugging a build failure in package
8109 @code{foo}; a typical session would look like this:
8113 @dots{} @i{build fails}
8114 $ cd /tmp/guix-build-foo.drv-0
8115 $ source ./environment-variables
8119 Now, you can invoke commands as if you were the daemon (almost) and
8120 troubleshoot your build process.
8122 Sometimes it happens that, for example, a package's tests pass when you
8123 run them manually but they fail when the daemon runs them. This can
8124 happen because the daemon runs builds in containers where, unlike in our
8125 environment above, network access is missing, @file{/bin/sh} does not
8126 exist, etc. (@pxref{Build Environment Setup}).
8128 In such cases, you may need to run inspect the build process from within
8129 a container similar to the one the build daemon creates:
8134 $ cd /tmp/guix-build-foo.drv-0
8135 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
8136 [env]# source ./environment-variables
8140 Here, @command{guix environment -C} creates a container and spawns a new
8141 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
8142 strace gdb} part adds the @command{strace} and @command{gdb} commands to
8143 the container, which would may find handy while debugging. The
8144 @option{--no-grafts} option makes sure we get the exact same
8145 environment, with ungrafted packages (@pxref{Security Updates}, for more
8148 To get closer to a container like that used by the build daemon, we can
8149 remove @file{/bin/sh}:
8155 (Don't worry, this is harmless: this is all happening in the throw-away
8156 container created by @command{guix environment}.)
8158 The @command{strace} command is probably not in the search path, but we
8162 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
8165 In this way, not only you will have reproduced the environment variables
8166 the daemon uses, you will also be running the build process in a container
8167 similar to the one the daemon uses.
8170 @node Invoking guix edit
8171 @section Invoking @command{guix edit}
8173 @cindex @command{guix edit}
8174 @cindex package definition, editing
8175 So many packages, so many source files! The @command{guix edit} command
8176 facilitates the life of users and packagers by pointing their editor at
8177 the source file containing the definition of the specified packages.
8181 guix edit gcc@@4.9 vim
8185 launches the program specified in the @code{VISUAL} or in the
8186 @code{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
8189 If you are using a Guix Git checkout (@pxref{Building from Git}), or
8190 have created your own packages on @code{GUIX_PACKAGE_PATH}
8191 (@pxref{Package Modules}), you will be able to edit the package
8192 recipes. In other cases, you will be able to examine the read-only recipes
8193 for packages currently in the store.
8196 @node Invoking guix download
8197 @section Invoking @command{guix download}
8199 @cindex @command{guix download}
8200 @cindex downloading package sources
8201 When writing a package definition, developers typically need to download
8202 a source tarball, compute its SHA256 hash, and write that
8203 hash in the package definition (@pxref{Defining Packages}). The
8204 @command{guix download} tool helps with this task: it downloads a file
8205 from the given URI, adds it to the store, and prints both its file name
8206 in the store and its SHA256 hash.
8208 The fact that the downloaded file is added to the store saves bandwidth:
8209 when the developer eventually tries to build the newly defined package
8210 with @command{guix build}, the source tarball will not have to be
8211 downloaded again because it is already in the store. It is also a
8212 convenient way to temporarily stash files, which may be deleted
8213 eventually (@pxref{Invoking guix gc}).
8215 The @command{guix download} command supports the same URIs as used in
8216 package definitions. In particular, it supports @code{mirror://} URIs.
8217 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
8218 Guile bindings for GnuTLS are available in the user's environment; when
8219 they are not available, an error is raised. @xref{Guile Preparations,
8220 how to install the GnuTLS bindings for Guile,, gnutls-guile,
8221 GnuTLS-Guile}, for more information.
8223 @command{guix download} verifies HTTPS server certificates by loading
8224 the certificates of X.509 authorities from the directory pointed to by
8225 the @code{SSL_CERT_DIR} environment variable (@pxref{X.509
8226 Certificates}), unless @option{--no-check-certificate} is used.
8228 The following options are available:
8231 @item --format=@var{fmt}
8233 Write the hash in the format specified by @var{fmt}. For more
8234 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
8236 @item --no-check-certificate
8237 Do not validate the X.509 certificates of HTTPS servers.
8239 When using this option, you have @emph{absolutely no guarantee} that you
8240 are communicating with the authentic server responsible for the given
8241 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
8243 @item --output=@var{file}
8244 @itemx -o @var{file}
8245 Save the downloaded file to @var{file} instead of adding it to the
8249 @node Invoking guix hash
8250 @section Invoking @command{guix hash}
8252 @cindex @command{guix hash}
8253 The @command{guix hash} command computes the SHA256 hash of a file.
8254 It is primarily a convenience tool for anyone contributing to the
8255 distribution: it computes the cryptographic hash of a file, which can be
8256 used in the definition of a package (@pxref{Defining Packages}).
8258 The general syntax is:
8261 guix hash @var{option} @var{file}
8264 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
8265 hash of data read from standard input. @command{guix hash} has the
8270 @item --format=@var{fmt}
8272 Write the hash in the format specified by @var{fmt}.
8274 Supported formats: @code{nix-base32}, @code{base32}, @code{base16}
8275 (@code{hex} and @code{hexadecimal} can be used as well).
8277 If the @option{--format} option is not specified, @command{guix hash}
8278 will output the hash in @code{nix-base32}. This representation is used
8279 in the definitions of packages.
8283 Compute the hash on @var{file} recursively.
8285 In this case, the hash is computed on an archive containing @var{file},
8286 including its children if it is a directory. Some of the metadata of
8287 @var{file} is part of the archive; for instance, when @var{file} is a
8288 regular file, the hash is different depending on whether @var{file} is
8289 executable or not. Metadata such as time stamps has no impact on the
8290 hash (@pxref{Invoking guix archive}).
8291 @c FIXME: Replace xref above with xref to an ``Archive'' section when
8296 When combined with @option{--recursive}, exclude version control system
8297 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.)
8300 As an example, here is how you would compute the hash of a Git checkout,
8301 which is useful when using the @code{git-fetch} method (@pxref{origin
8305 $ git clone http://example.org/foo.git
8311 @node Invoking guix import
8312 @section Invoking @command{guix import}
8314 @cindex importing packages
8315 @cindex package import
8316 @cindex package conversion
8317 @cindex Invoking @command{guix import}
8318 The @command{guix import} command is useful for people who would like to
8319 add a package to the distribution with as little work as
8320 possible---a legitimate demand. The command knows of a few
8321 repositories from which it can ``import'' package metadata. The result
8322 is a package definition, or a template thereof, in the format we know
8323 (@pxref{Defining Packages}).
8325 The general syntax is:
8328 guix import @var{importer} @var{options}@dots{}
8331 @var{importer} specifies the source from which to import package
8332 metadata, and @var{options} specifies a package identifier and other
8333 options specific to @var{importer}. Currently, the available
8338 Import metadata for the given GNU package. This provides a template
8339 for the latest version of that GNU package, including the hash of its
8340 source tarball, and its canonical synopsis and description.
8342 Additional information such as the package dependencies and its
8343 license needs to be figured out manually.
8345 For example, the following command returns a package definition for
8349 guix import gnu hello
8352 Specific command-line options are:
8355 @item --key-download=@var{policy}
8356 As for @code{guix refresh}, specify the policy to handle missing OpenPGP
8357 keys when verifying the package signature. @xref{Invoking guix
8358 refresh, @code{--key-download}}.
8363 Import metadata from the @uref{https://pypi.python.org/, Python Package
8364 Index}. Information is taken from the JSON-formatted description
8365 available at @code{pypi.python.org} and usually includes all the relevant
8366 information, including package dependencies. For maximum efficiency, it
8367 is recommended to install the @command{unzip} utility, so that the
8368 importer can unzip Python wheels and gather data from them.
8370 The command below imports metadata for the @code{itsdangerous} Python
8374 guix import pypi itsdangerous
8380 Traverse the dependency graph of the given upstream package recursively
8381 and generate package expressions for all those packages that are not yet
8387 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
8388 is taken from the JSON-formatted description available at
8389 @code{rubygems.org} and includes most relevant information, including
8390 runtime dependencies. There are some caveats, however. The metadata
8391 doesn't distinguish between synopses and descriptions, so the same string
8392 is used for both fields. Additionally, the details of non-Ruby
8393 dependencies required to build native extensions is unavailable and left
8394 as an exercise to the packager.
8396 The command below imports metadata for the @code{rails} Ruby package:
8399 guix import gem rails
8405 Traverse the dependency graph of the given upstream package recursively
8406 and generate package expressions for all those packages that are not yet
8412 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
8413 Information is taken from the JSON-formatted metadata provided through
8414 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
8415 relevant information, such as module dependencies. License information
8416 should be checked closely. If Perl is available in the store, then the
8417 @code{corelist} utility will be used to filter core modules out of the
8418 list of dependencies.
8420 The command command below imports metadata for the @code{Acme::Boolean}
8424 guix import cpan Acme::Boolean
8429 @cindex Bioconductor
8430 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
8431 central repository for the @uref{http://r-project.org, GNU@tie{}R
8432 statistical and graphical environment}.
8434 Information is extracted from the @code{DESCRIPTION} file of the package.
8436 The command command below imports metadata for the @code{Cairo}
8440 guix import cran Cairo
8443 When @code{--recursive} is added, the importer will traverse the
8444 dependency graph of the given upstream package recursively and generate
8445 package expressions for all those packages that are not yet in Guix.
8447 When @code{--archive=bioconductor} is added, metadata is imported from
8448 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
8449 packages for for the analysis and comprehension of high-throughput
8450 genomic data in bioinformatics.
8452 Information is extracted from the @code{DESCRIPTION} file of a package
8453 published on the web interface of the Bioconductor SVN repository.
8455 The command below imports metadata for the @code{GenomicRanges}
8459 guix import cran --archive=bioconductor GenomicRanges
8465 Import metadata from @uref{http://www.ctan.org/, CTAN}, the
8466 comprehensive TeX archive network for TeX packages that are part of the
8467 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
8469 Information about the package is obtained through the XML API provided
8470 by CTAN, while the source code is downloaded from the SVN repository of
8471 the Tex Live project. This is done because the CTAN does not keep
8474 The command command below imports metadata for the @code{fontspec}
8478 guix import texlive fontspec
8481 When @code{--archive=DIRECTORY} is added, the source code is downloaded
8482 not from the @file{latex} sub-directory of the @file{texmf-dist/source}
8483 tree in the TeX Live SVN repository, but from the specified sibling
8484 directory under the same root.
8486 The command below imports metadata for the @code{ifxetex} package from
8487 CTAN while fetching the sources from the directory
8488 @file{texmf/source/generic}:
8491 guix import texlive --archive=generic ifxetex
8495 @cindex JSON, import
8496 Import package metadata from a local JSON file. Consider the following
8497 example package definition in JSON format:
8503 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
8504 "build-system": "gnu",
8505 "home-page": "https://www.gnu.org/software/hello/",
8506 "synopsis": "Hello, GNU world: An example GNU package",
8507 "description": "GNU Hello prints a greeting.",
8508 "license": "GPL-3.0+",
8509 "native-inputs": ["gcc@@6"]
8513 The field names are the same as for the @code{<package>} record
8514 (@xref{Defining Packages}). References to other packages are provided
8515 as JSON lists of quoted package specification strings such as
8516 @code{guile} or @code{guile@@2.0}.
8518 The importer also supports a more explicit source definition using the
8519 common fields for @code{<origin>} records:
8525 "method": "url-fetch",
8526 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
8528 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
8535 The command below reads metadata from the JSON file @code{hello.json}
8536 and outputs a package expression:
8539 guix import json hello.json
8543 Import metadata from a local copy of the source of the
8544 @uref{http://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
8545 relies on the @command{nix-instantiate} command of
8546 @uref{http://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
8547 typically written in a mixture of Nix-language and Bash code. This
8548 command only imports the high-level package structure that is written in
8549 the Nix language. It normally includes all the basic fields of a
8552 When importing a GNU package, the synopsis and descriptions are replaced
8553 by their canonical upstream variant.
8555 Usually, you will first need to do:
8558 export NIX_REMOTE=daemon
8562 so that @command{nix-instantiate} does not try to open the Nix database.
8564 As an example, the command below imports the package definition of
8565 LibreOffice (more precisely, it imports the definition of the package
8566 bound to the @code{libreoffice} top-level attribute):
8569 guix import nix ~/path/to/nixpkgs libreoffice
8574 Import metadata from the Haskell community's central package archive
8575 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
8576 Cabal files and includes all the relevant information, including package
8579 Specific command-line options are:
8584 Read a Cabal file from standard input.
8585 @item --no-test-dependencies
8587 Do not include dependencies required only by the test suites.
8588 @item --cabal-environment=@var{alist}
8589 @itemx -e @var{alist}
8590 @var{alist} is a Scheme alist defining the environment in which the
8591 Cabal conditionals are evaluated. The accepted keys are: @code{os},
8592 @code{arch}, @code{impl} and a string representing the name of a flag.
8593 The value associated with a flag has to be either the symbol
8594 @code{true} or @code{false}. The value associated with other keys
8595 has to conform to the Cabal file format definition. The default value
8596 associated with the keys @code{os}, @code{arch} and @code{impl} is
8597 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
8600 Traverse the dependency graph of the given upstream package recursively
8601 and generate package expressions for all those packages that are not yet
8605 The command below imports metadata for the latest version of the
8606 @code{HTTP} Haskell package without including test dependencies and
8607 specifying the value of the flag @samp{network-uri} as @code{false}:
8610 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
8613 A specific package version may optionally be specified by following the
8614 package name by an at-sign and a version number as in the following example:
8617 guix import hackage mtl@@2.1.3.1
8622 The @code{stackage} importer is a wrapper around the @code{hackage} one.
8623 It takes a package name, looks up the package version included in a
8624 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
8625 release and uses the @code{hackage} importer to retrieve its metadata.
8626 Note that it is up to you to select an LTS release compatible with the
8627 GHC compiler used by Guix.
8629 Specific command-line options are:
8632 @item --no-test-dependencies
8634 Do not include dependencies required only by the test suites.
8635 @item --lts-version=@var{version}
8636 @itemx -l @var{version}
8637 @var{version} is the desired LTS release version. If omitted the latest
8641 Traverse the dependency graph of the given upstream package recursively
8642 and generate package expressions for all those packages that are not yet
8646 The command below imports metadata for the @code{HTTP} Haskell package
8647 included in the LTS Stackage release version 7.18:
8650 guix import stackage --lts-version=7.18 HTTP
8655 Import metadata from an Emacs Lisp Package Archive (ELPA) package
8656 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
8658 Specific command-line options are:
8661 @item --archive=@var{repo}
8662 @itemx -a @var{repo}
8663 @var{repo} identifies the archive repository from which to retrieve the
8664 information. Currently the supported repositories and their identifiers
8668 @uref{http://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
8669 identifier. This is the default.
8671 Packages from @code{elpa.gnu.org} are signed with one of the keys
8672 contained in the GnuPG keyring at
8673 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
8674 @code{emacs} package (@pxref{Package Installation, ELPA package
8675 signatures,, emacs, The GNU Emacs Manual}).
8678 @uref{http://stable.melpa.org/packages, MELPA-Stable}, selected by the
8679 @code{melpa-stable} identifier.
8682 @uref{http://melpa.org/packages, MELPA}, selected by the @code{melpa}
8688 Traverse the dependency graph of the given upstream package recursively
8689 and generate package expressions for all those packages that are not yet
8695 Import metadata from the crates.io Rust package repository
8696 @uref{https://crates.io, crates.io}.
8701 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
8702 repository used by the OCaml community.
8705 The structure of the @command{guix import} code is modular. It would be
8706 useful to have more importers for other package formats, and your help
8707 is welcome here (@pxref{Contributing}).
8709 @node Invoking guix refresh
8710 @section Invoking @command{guix refresh}
8712 @cindex @command {guix refresh}
8713 The primary audience of the @command{guix refresh} command is developers
8714 of the GNU software distribution. By default, it reports any packages
8715 provided by the distribution that are outdated compared to the latest
8716 upstream version, like this:
8720 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
8721 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
8724 Alternately, one can specify packages to consider, in which case a
8725 warning is emitted for packages that lack an updater:
8728 $ guix refresh coreutils guile guile-ssh
8729 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
8730 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
8733 @command{guix refresh} browses the upstream repository of each package and determines
8734 the highest version number of the releases therein. The command
8735 knows how to update specific types of packages: GNU packages, ELPA
8736 packages, etc.---see the documentation for @option{--type} below. There
8737 are many packages, though, for which it lacks a method to determine
8738 whether a new upstream release is available. However, the mechanism is
8739 extensible, so feel free to get in touch with us to add a new method!
8744 Consider the packages specified, and all the packages upon which they depend.
8747 $ guix refresh --recursive coreutils
8748 gnu/packages/acl.scm:35:2: warning: no updater for acl
8749 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
8750 gnu/packages/xml.scm:68:2: warning: no updater for expat
8751 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
8757 Sometimes the upstream name differs from the package name used in Guix,
8758 and @command{guix refresh} needs a little help. Most updaters honor the
8759 @code{upstream-name} property in package definitions, which can be used
8763 (define-public network-manager
8765 (name "network-manager")
8767 (properties '((upstream-name . "NetworkManager")))))
8770 When passed @code{--update}, it modifies distribution source files to
8771 update the version numbers and source tarball hashes of those package
8772 recipes (@pxref{Defining Packages}). This is achieved by downloading
8773 each package's latest source tarball and its associated OpenPGP
8774 signature, authenticating the downloaded tarball against its signature
8775 using @command{gpg}, and finally computing its hash. When the public
8776 key used to sign the tarball is missing from the user's keyring, an
8777 attempt is made to automatically retrieve it from a public key server;
8778 when this is successful, the key is added to the user's keyring; otherwise,
8779 @command{guix refresh} reports an error.
8781 The following options are supported:
8785 @item --expression=@var{expr}
8786 @itemx -e @var{expr}
8787 Consider the package @var{expr} evaluates to.
8789 This is useful to precisely refer to a package, as in this example:
8792 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
8795 This command lists the dependents of the ``final'' libc (essentially all
8800 Update distribution source files (package recipes) in place. This is
8801 usually run from a checkout of the Guix source tree (@pxref{Running
8802 Guix Before It Is Installed}):
8805 $ ./pre-inst-env guix refresh -s non-core -u
8808 @xref{Defining Packages}, for more information on package definitions.
8810 @item --select=[@var{subset}]
8811 @itemx -s @var{subset}
8812 Select all the packages in @var{subset}, one of @code{core} or
8815 The @code{core} subset refers to all the packages at the core of the
8816 distribution---i.e., packages that are used to build ``everything
8817 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
8818 changing one of these packages in the distribution entails a rebuild of
8819 all the others. Thus, such updates are an inconvenience to users in
8820 terms of build time or bandwidth used to achieve the upgrade.
8822 The @code{non-core} subset refers to the remaining packages. It is
8823 typically useful in cases where an update of the core packages would be
8826 @item --manifest=@var{file}
8827 @itemx -m @var{file}
8828 Select all the packages from the manifest in @var{file}. This is useful to
8829 check if any packages of the user manifest can be updated.
8831 @item --type=@var{updater}
8832 @itemx -t @var{updater}
8833 Select only packages handled by @var{updater} (may be a comma-separated
8834 list of updaters). Currently, @var{updater} may be one of:
8838 the updater for GNU packages;
8840 the updater for GNOME packages;
8842 the updater for KDE packages;
8844 the updater for X.org packages;
8846 the updater for packages hosted on kernel.org;
8848 the updater for @uref{http://elpa.gnu.org/, ELPA} packages;
8850 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
8852 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
8854 the updater for @uref{http://www.cpan.org/, CPAN} packages;
8856 the updater for @uref{https://pypi.python.org, PyPI} packages.
8858 the updater for @uref{https://rubygems.org, RubyGems} packages.
8860 the updater for @uref{https://github.com, GitHub} packages.
8862 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
8864 the updater for @uref{https://www.stackage.org, Stackage} packages.
8866 the updater for @uref{https://crates.io, Crates} packages.
8868 the updater for @uref{https://launchpad.net, Launchpad} packages.
8871 For instance, the following command only checks for updates of Emacs
8872 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
8875 $ guix refresh --type=elpa,cran
8876 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
8877 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
8882 In addition, @command{guix refresh} can be passed one or more package
8883 names, as in this example:
8886 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
8890 The command above specifically updates the @code{emacs} and
8891 @code{idutils} packages. The @code{--select} option would have no
8892 effect in this case.
8894 When considering whether to upgrade a package, it is sometimes
8895 convenient to know which packages would be affected by the upgrade and
8896 should be checked for compatibility. For this the following option may
8897 be used when passing @command{guix refresh} one or more package names:
8901 @item --list-updaters
8903 List available updaters and exit (see @option{--type} above.)
8905 For each updater, display the fraction of packages it covers; at the
8906 end, display the fraction of packages covered by all these updaters.
8908 @item --list-dependent
8910 List top-level dependent packages that would need to be rebuilt as a
8911 result of upgrading one or more packages.
8913 @xref{Invoking guix graph, the @code{reverse-package} type of
8914 @command{guix graph}}, for information on how to visualize the list of
8915 dependents of a package.
8919 Be aware that the @code{--list-dependent} option only
8920 @emph{approximates} the rebuilds that would be required as a result of
8921 an upgrade. More rebuilds might be required under some circumstances.
8924 $ guix refresh --list-dependent flex
8925 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
8926 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
8929 The command above lists a set of packages that could be built to check
8930 for compatibility with an upgraded @code{flex} package.
8934 @item --list-transitive
8935 List all the packages which one or more packages depend upon.
8938 $ guix refresh --list-transitive flex
8939 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
8940 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{}
8945 The command above lists a set of packages which, when changed, would cause
8946 @code{flex} to be rebuilt.
8948 The following options can be used to customize GnuPG operation:
8952 @item --gpg=@var{command}
8953 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
8954 for in @code{$PATH}.
8956 @item --keyring=@var{file}
8957 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
8958 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
8959 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
8960 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
8961 information on a tool to manipulate keybox files).
8963 When this option is omitted, @command{guix refresh} uses
8964 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
8965 signing keys. OpenPGP signatures are checked against keys from this keyring;
8966 missing keys are downloaded to this keyring as well (see
8967 @option{--key-download} below.)
8969 You can export keys from your default GPG keyring into a keybox file using
8970 commands like this one:
8973 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
8976 Likewise, you can fetch keys to a specific keybox file like this:
8979 gpg --no-default-keyring --keyring mykeyring.kbx \
8980 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
8983 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
8984 Privacy Guard}, for more information on GPG's @option{--keyring} option.
8986 @item --key-download=@var{policy}
8987 Handle missing OpenPGP keys according to @var{policy}, which may be one
8992 Always download missing OpenPGP keys from the key server, and add them
8993 to the user's GnuPG keyring.
8996 Never try to download missing OpenPGP keys. Instead just bail out.
8999 When a package signed with an unknown OpenPGP key is encountered, ask
9000 the user whether to download it or not. This is the default behavior.
9003 @item --key-server=@var{host}
9004 Use @var{host} as the OpenPGP key server when importing a public key.
9008 The @code{github} updater uses the
9009 @uref{https://developer.github.com/v3/, GitHub API} to query for new
9010 releases. When used repeatedly e.g.@: when refreshing all packages,
9011 GitHub will eventually refuse to answer any further API requests. By
9012 default 60 API requests per hour are allowed, and a full refresh on all
9013 GitHub packages in Guix requires more than this. Authentication with
9014 GitHub through the use of an API token alleviates these limits. To use
9015 an API token, set the environment variable @code{GUIX_GITHUB_TOKEN} to a
9016 token procured from @uref{https://github.com/settings/tokens} or
9020 @node Invoking guix lint
9021 @section Invoking @command{guix lint}
9023 @cindex @command{guix lint}
9024 @cindex package, checking for errors
9025 The @command{guix lint} command is meant to help package developers avoid
9026 common errors and use a consistent style. It runs a number of checks on
9027 a given set of packages in order to find common mistakes in their
9028 definitions. Available @dfn{checkers} include (see
9029 @code{--list-checkers} for a complete list):
9034 Validate certain typographical and stylistic rules about package
9035 descriptions and synopses.
9037 @item inputs-should-be-native
9038 Identify inputs that should most likely be native inputs.
9044 @itemx source-file-name
9045 Probe @code{home-page} and @code{source} URLs and report those that are
9046 invalid. Suggest a @code{mirror://} URL when applicable. If the
9047 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
9048 URL. Check that the source file name is meaningful, e.g.@: is not just a
9049 version number or ``git-checkout'', without a declared @code{file-name}
9050 (@pxref{origin Reference}).
9052 @item source-unstable-tarball
9053 Parse the @code{source} URL to determine if a tarball from GitHub is
9054 autogenerated or if it is a release tarball. Unfortunately GitHub's
9055 autogenerated tarballs are sometimes regenerated.
9058 @cindex security vulnerabilities
9059 @cindex CVE, Common Vulnerabilities and Exposures
9060 Report known vulnerabilities found in the Common Vulnerabilities and
9061 Exposures (CVE) databases of the current and past year
9062 @uref{https://nvd.nist.gov/download.cfm#CVE_FEED, published by the US
9065 To view information about a particular vulnerability, visit pages such as:
9069 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
9071 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
9075 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
9076 @code{CVE-2015-7554}.
9078 Package developers can specify in package recipes the
9079 @uref{https://nvd.nist.gov/cpe.cfm,Common Platform Enumeration (CPE)}
9080 name and version of the package when they differ from the name or version
9081 that Guix uses, as in this example:
9087 ;; CPE calls this package "grub2".
9088 (properties '((cpe-name . "grub2")
9089 (cpe-version . "2.3")))
9092 @c See <http://www.openwall.com/lists/oss-security/2017/03/15/3>.
9093 Some entries in the CVE database do not specify which version of a
9094 package they apply to, and would thus ``stick around'' forever. Package
9095 developers who found CVE alerts and verified they can be ignored can
9096 declare them as in this example:
9102 ;; These CVEs no longer apply and can be safely ignored.
9103 (properties `((lint-hidden-cve . ("CVE-2011-0433"
9106 "CVE-2011-5244")))))
9110 Warn about obvious source code formatting issues: trailing white space,
9111 use of tabulations, etc.
9114 The general syntax is:
9117 guix lint @var{options} @var{package}@dots{}
9120 If no package is given on the command line, then all packages are checked.
9121 The @var{options} may be zero or more of the following:
9124 @item --list-checkers
9126 List and describe all the available checkers that will be run on packages
9131 Only enable the checkers specified in a comma-separated list using the
9132 names returned by @code{--list-checkers}.
9136 @node Invoking guix size
9137 @section Invoking @command{guix size}
9140 @cindex package size
9142 @cindex @command{guix size}
9143 The @command{guix size} command helps package developers profile the
9144 disk usage of packages. It is easy to overlook the impact of an
9145 additional dependency added to a package, or the impact of using a
9146 single output for a package that could easily be split (@pxref{Packages
9147 with Multiple Outputs}). Such are the typical issues that
9148 @command{guix size} can highlight.
9150 The command can be passed one or more package specifications
9151 such as @code{gcc@@4.8}
9152 or @code{guile:debug}, or a file name in the store. Consider this
9156 $ guix size coreutils
9157 store item total self
9158 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
9159 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
9160 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
9161 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
9162 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
9163 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
9164 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
9165 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
9170 The store items listed here constitute the @dfn{transitive closure} of
9171 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
9172 would be returned by:
9175 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
9178 Here the output shows three columns next to store items. The first column,
9179 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
9180 the store item---that is, its own size plus the size of all its
9181 dependencies. The next column, labeled ``self'', shows the size of the
9182 item itself. The last column shows the ratio of the size of the item
9183 itself to the space occupied by all the items listed here.
9185 In this example, we see that the closure of Coreutils weighs in at
9186 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
9187 libraries. (That libc and GCC's libraries represent a large fraction of
9188 the closure is not a problem @i{per se} because they are always available
9189 on the system anyway.)
9191 When the package(s) passed to @command{guix size} are available in the
9192 store@footnote{More precisely, @command{guix size} looks for the
9193 @emph{ungrafted} variant of the given package(s), as returned by
9194 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
9195 for information on grafts.}, @command{guix size} queries the daemon to determine its
9196 dependencies, and measures its size in the store, similar to @command{du
9197 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
9200 When the given packages are @emph{not} in the store, @command{guix size}
9201 reports information based on the available substitutes
9202 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
9203 store items that are not even on disk, only available remotely.
9205 You can also specify several package names:
9208 $ guix size coreutils grep sed bash
9209 store item total self
9210 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
9211 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
9212 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
9213 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
9219 In this example we see that the combination of the four packages takes
9220 102.3@tie{}MiB in total, which is much less than the sum of each closure
9221 since they have a lot of dependencies in common.
9223 The available options are:
9227 @item --substitute-urls=@var{urls}
9228 Use substitute information from @var{urls}.
9229 @xref{client-substitute-urls, the same option for @code{guix build}}.
9231 @item --sort=@var{key}
9232 Sort lines according to @var{key}, one of the following options:
9236 the size of each item (the default);
9238 the total size of the item's closure.
9241 @item --map-file=@var{file}
9242 Write a graphical map of disk usage in PNG format to @var{file}.
9244 For the example above, the map looks like this:
9246 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
9247 produced by @command{guix size}}
9249 This option requires that
9250 @uref{http://wingolog.org/software/guile-charting/, Guile-Charting} be
9251 installed and visible in Guile's module search path. When that is not
9252 the case, @command{guix size} fails as it tries to load it.
9254 @item --system=@var{system}
9255 @itemx -s @var{system}
9256 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
9260 @node Invoking guix graph
9261 @section Invoking @command{guix graph}
9264 @cindex @command{guix graph}
9265 @cindex package dependencies
9266 Packages and their dependencies form a @dfn{graph}, specifically a
9267 directed acyclic graph (DAG). It can quickly become difficult to have a
9268 mental model of the package DAG, so the @command{guix graph} command
9269 provides a visual representation of the DAG. By default,
9270 @command{guix graph} emits a DAG representation in the input format of
9271 @uref{http://www.graphviz.org/, Graphviz}, so its output can be passed
9272 directly to the @command{dot} command of Graphviz. It can also emit an
9273 HTML page with embedded JavaScript code to display a ``chord diagram''
9274 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
9275 emit Cypher queries to construct a graph in a graph database supporting
9276 the @uref{http://www.opencypher.org/, openCypher} query language.
9277 The general syntax is:
9280 guix graph @var{options} @var{package}@dots{}
9283 For example, the following command generates a PDF file representing the
9284 package DAG for the GNU@tie{}Core Utilities, showing its build-time
9288 guix graph coreutils | dot -Tpdf > dag.pdf
9291 The output looks like this:
9293 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
9295 Nice little graph, no?
9297 But there is more than one graph! The one above is concise: it is the
9298 graph of package objects, omitting implicit inputs such as GCC, libc,
9299 grep, etc. It is often useful to have such a concise graph, but
9300 sometimes one may want to see more details. @command{guix graph} supports
9301 several types of graphs, allowing you to choose the level of detail:
9305 This is the default type used in the example above. It shows the DAG of
9306 package objects, excluding implicit dependencies. It is concise, but
9307 filters out many details.
9309 @item reverse-package
9310 This shows the @emph{reverse} DAG of packages. For example:
9313 guix graph --type=reverse-package ocaml
9316 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
9317 you are also interested in cases where OCaml is an implicit dependency, see
9318 @code{reverse-bag} below.)
9320 Note that for core packages this can yield huge graphs. If all you want
9321 is to know the number of packages that depend on a given package, use
9322 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
9323 @option{--list-dependent}}).
9326 This is the package DAG, @emph{including} implicit inputs.
9328 For instance, the following command:
9331 guix graph --type=bag-emerged coreutils | dot -Tpdf > dag.pdf
9334 ...@: yields this bigger graph:
9336 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
9338 At the bottom of the graph, we see all the implicit inputs of
9339 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
9341 Now, note that the dependencies of these implicit inputs---that is, the
9342 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
9343 here, for conciseness.
9346 Similar to @code{bag-emerged}, but this time including all the bootstrap
9349 @item bag-with-origins
9350 Similar to @code{bag}, but also showing origins and their dependencies.
9353 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
9354 it also takes implicit dependencies into account. For example:
9357 guix graph -t reverse-bag dune
9361 ...@: yields the graph of all packages that depend on Dune, directly or
9362 indirectly. Since Dune is an @emph{implicit} dependency of many packages
9363 @i{via} @code{dune-build-system}, this shows a large number of packages,
9364 whereas @code{reverse-package} would show very few if any.
9367 This is the most detailed representation: It shows the DAG of
9368 derivations (@pxref{Derivations}) and plain store items. Compared to
9369 the above representation, many additional nodes are visible, including
9370 build scripts, patches, Guile modules, etc.
9372 For this type of graph, it is also possible to pass a @file{.drv} file
9373 name instead of a package name, as in:
9376 guix graph -t derivation `guix system build -d my-config.scm`
9380 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
9381 For example, the following command shows the graph for the package
9382 module that defines the @code{guile} package:
9385 guix graph -t module guile | dot -Tpdf > module-graph.pdf
9389 All the types above correspond to @emph{build-time dependencies}. The
9390 following graph type represents the @emph{run-time dependencies}:
9394 This is the graph of @dfn{references} of a package output, as returned
9395 by @command{guix gc --references} (@pxref{Invoking guix gc}).
9397 If the given package output is not available in the store, @command{guix
9398 graph} attempts to obtain dependency information from substitutes.
9400 Here you can also pass a store file name instead of a package name. For
9401 example, the command below produces the reference graph of your profile
9402 (which can be big!):
9405 guix graph -t references `readlink -f ~/.guix-profile`
9409 This is the graph of the @dfn{referrers} of a store item, as returned by
9410 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
9412 This relies exclusively on local information from your store. For
9413 instance, let us suppose that the current Inkscape is available in 10
9414 profiles on your machine; @command{guix graph -t referrers inkscape}
9415 will show a graph rooted at Inkscape and with those 10 profiles linked
9418 It can help determine what is preventing a store item from being garbage
9423 The available options are the following:
9426 @item --type=@var{type}
9427 @itemx -t @var{type}
9428 Produce a graph output of @var{type}, where @var{type} must be one of
9429 the values listed above.
9432 List the supported graph types.
9434 @item --backend=@var{backend}
9435 @itemx -b @var{backend}
9436 Produce a graph using the selected @var{backend}.
9438 @item --list-backends
9439 List the supported graph backends.
9441 Currently, the available backends are Graphviz and d3.js.
9443 @item --expression=@var{expr}
9444 @itemx -e @var{expr}
9445 Consider the package @var{expr} evaluates to.
9447 This is useful to precisely refer to a package, as in this example:
9450 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
9453 @item --system=@var{system}
9454 @itemx -s @var{system}
9455 Display the graph for @var{system}---e.g., @code{i686-linux}.
9457 The package dependency graph is largely architecture-independent, but there
9458 are some architecture-dependent bits that this option allows you to visualize.
9463 @node Invoking guix publish
9464 @section Invoking @command{guix publish}
9466 @cindex @command{guix publish}
9467 The purpose of @command{guix publish} is to enable users to easily share
9468 their store with others, who can then use it as a substitute server
9469 (@pxref{Substitutes}).
9471 When @command{guix publish} runs, it spawns an HTTP server which allows
9472 anyone with network access to obtain substitutes from it. This means
9473 that any machine running Guix can also act as if it were a build farm,
9474 since the HTTP interface is compatible with Hydra, the software behind
9475 the @code{@value{SUBSTITUTE-SERVER}} build farm.
9477 For security, each substitute is signed, allowing recipients to check
9478 their authenticity and integrity (@pxref{Substitutes}). Because
9479 @command{guix publish} uses the signing key of the system, which is only
9480 readable by the system administrator, it must be started as root; the
9481 @code{--user} option makes it drop root privileges early on.
9483 The signing key pair must be generated before @command{guix publish} is
9484 launched, using @command{guix archive --generate-key} (@pxref{Invoking
9487 The general syntax is:
9490 guix publish @var{options}@dots{}
9493 Running @command{guix publish} without any additional arguments will
9494 spawn an HTTP server on port 8080:
9500 Once a publishing server has been authorized (@pxref{Invoking guix
9501 archive}), the daemon may download substitutes from it:
9504 guix-daemon --substitute-urls=http://example.org:8080
9507 By default, @command{guix publish} compresses archives on the fly as it
9508 serves them. This ``on-the-fly'' mode is convenient in that it requires
9509 no setup and is immediately available. However, when serving lots of
9510 clients, we recommend using the @option{--cache} option, which enables
9511 caching of the archives before they are sent to clients---see below for
9512 details. The @command{guix weather} command provides a handy way to
9513 check what a server provides (@pxref{Invoking guix weather}).
9515 As a bonus, @command{guix publish} also serves as a content-addressed
9516 mirror for source files referenced in @code{origin} records
9517 (@pxref{origin Reference}). For instance, assuming @command{guix
9518 publish} is running on @code{example.org}, the following URL returns the
9519 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
9520 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
9523 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
9526 Obviously, these URLs only work for files that are in the store; in
9527 other cases, they return 404 (``Not Found'').
9529 @cindex build logs, publication
9530 Build logs are available from @code{/log} URLs like:
9533 http://example.org/log/gwspk@dots{}-guile-2.2.3
9537 When @command{guix-daemon} is configured to save compressed build logs,
9538 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
9539 URLs return the compressed log as-is, with an appropriate
9540 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
9541 running @command{guix-daemon} with @code{--log-compression=gzip} since
9542 Web browsers can automatically decompress it, which is not the case with
9545 The following options are available:
9548 @item --port=@var{port}
9549 @itemx -p @var{port}
9550 Listen for HTTP requests on @var{port}.
9552 @item --listen=@var{host}
9553 Listen on the network interface for @var{host}. The default is to
9554 accept connections from any interface.
9556 @item --user=@var{user}
9557 @itemx -u @var{user}
9558 Change privileges to @var{user} as soon as possible---i.e., once the
9559 server socket is open and the signing key has been read.
9561 @item --compression[=@var{level}]
9562 @itemx -C [@var{level}]
9563 Compress data using the given @var{level}. When @var{level} is zero,
9564 disable compression. The range 1 to 9 corresponds to different gzip
9565 compression levels: 1 is the fastest, and 9 is the best (CPU-intensive).
9568 Unless @option{--cache} is used, compression occurs on the fly and
9569 the compressed streams are not
9570 cached. Thus, to reduce load on the machine that runs @command{guix
9571 publish}, it may be a good idea to choose a low compression level, to
9572 run @command{guix publish} behind a caching proxy, or to use
9573 @option{--cache}. Using @option{--cache} has the advantage that it
9574 allows @command{guix publish} to add @code{Content-Length} HTTP header
9577 @item --cache=@var{directory}
9578 @itemx -c @var{directory}
9579 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
9580 and only serve archives that are in cache.
9582 When this option is omitted, archives and meta-data are created
9583 on-the-fly. This can reduce the available bandwidth, especially when
9584 compression is enabled, since this may become CPU-bound. Another
9585 drawback of the default mode is that the length of archives is not known
9586 in advance, so @command{guix publish} does not add a
9587 @code{Content-Length} HTTP header to its responses, which in turn
9588 prevents clients from knowing the amount of data being downloaded.
9590 Conversely, when @option{--cache} is used, the first request for a store
9591 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
9592 background process to @dfn{bake} the archive---computing its
9593 @code{.narinfo} and compressing the archive, if needed. Once the
9594 archive is cached in @var{directory}, subsequent requests succeed and
9595 are served directly from the cache, which guarantees that clients get
9596 the best possible bandwidth.
9598 The ``baking'' process is performed by worker threads. By default, one
9599 thread per CPU core is created, but this can be customized. See
9600 @option{--workers} below.
9602 When @option{--ttl} is used, cached entries are automatically deleted
9603 when they have expired.
9605 @item --workers=@var{N}
9606 When @option{--cache} is used, request the allocation of @var{N} worker
9607 threads to ``bake'' archives.
9609 @item --ttl=@var{ttl}
9610 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
9611 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
9612 days, @code{1m} means 1 month, and so on.
9614 This allows the user's Guix to keep substitute information in cache for
9615 @var{ttl}. However, note that @code{guix publish} does not itself
9616 guarantee that the store items it provides will indeed remain available
9617 for as long as @var{ttl}.
9619 Additionally, when @option{--cache} is used, cached entries that have
9620 not been accessed for @var{ttl} and that no longer have a corresponding
9621 item in the store, may be deleted.
9623 @item --nar-path=@var{path}
9624 Use @var{path} as the prefix for the URLs of ``nar'' files
9625 (@pxref{Invoking guix archive, normalized archives}).
9627 By default, nars are served at a URL such as
9628 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
9629 change the @code{/nar} part to @var{path}.
9631 @item --public-key=@var{file}
9632 @itemx --private-key=@var{file}
9633 Use the specific @var{file}s as the public/private key pair used to sign
9634 the store items being published.
9636 The files must correspond to the same key pair (the private key is used
9637 for signing and the public key is merely advertised in the signature
9638 metadata). They must contain keys in the canonical s-expression format
9639 as produced by @command{guix archive --generate-key} (@pxref{Invoking
9640 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
9641 @file{/etc/guix/signing-key.sec} are used.
9643 @item --repl[=@var{port}]
9644 @itemx -r [@var{port}]
9645 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
9646 Reference Manual}) on @var{port} (37146 by default). This is used
9647 primarily for debugging a running @command{guix publish} server.
9650 Enabling @command{guix publish} on Guix System is a one-liner: just
9651 instantiate a @code{guix-publish-service-type} service in the @code{services} field
9652 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
9653 @code{guix-publish-service-type}}).
9655 If you are instead running Guix on a ``foreign distro'', follow these
9660 If your host distro uses the systemd init system:
9663 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
9664 /etc/systemd/system/
9665 # systemctl start guix-publish && systemctl enable guix-publish
9669 If your host distro uses the Upstart init system:
9672 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
9673 # start guix-publish
9677 Otherwise, proceed similarly with your distro's init system.
9680 @node Invoking guix challenge
9681 @section Invoking @command{guix challenge}
9683 @cindex reproducible builds
9684 @cindex verifiable builds
9685 @cindex @command{guix challenge}
9687 Do the binaries provided by this server really correspond to the source
9688 code it claims to build? Is a package build process deterministic?
9689 These are the questions the @command{guix challenge} command attempts to
9692 The former is obviously an important question: Before using a substitute
9693 server (@pxref{Substitutes}), one had better @emph{verify} that it
9694 provides the right binaries, and thus @emph{challenge} it. The latter
9695 is what enables the former: If package builds are deterministic, then
9696 independent builds of the package should yield the exact same result,
9697 bit for bit; if a server provides a binary different from the one
9698 obtained locally, it may be either corrupt or malicious.
9700 We know that the hash that shows up in @file{/gnu/store} file names is
9701 the hash of all the inputs of the process that built the file or
9702 directory---compilers, libraries, build scripts,
9703 etc. (@pxref{Introduction}). Assuming deterministic build processes,
9704 one store file name should map to exactly one build output.
9705 @command{guix challenge} checks whether there is, indeed, a single
9706 mapping by comparing the build outputs of several independent builds of
9707 any given store item.
9709 The command output looks like this:
9712 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
9713 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
9714 updating list of substitutes from 'https://guix.example.org'... 100.0%
9715 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
9716 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
9717 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
9718 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
9719 /gnu/store/@dots{}-git-2.5.0 contents differ:
9720 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
9721 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
9722 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
9723 /gnu/store/@dots{}-pius-2.1.1 contents differ:
9724 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
9725 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
9726 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
9730 6,406 store items were analyzed:
9731 - 4,749 (74.1%) were identical
9732 - 525 (8.2%) differed
9733 - 1,132 (17.7%) were inconclusive
9737 In this example, @command{guix challenge} first scans the store to
9738 determine the set of locally-built derivations---as opposed to store
9739 items that were downloaded from a substitute server---and then queries
9740 all the substitute servers. It then reports those store items for which
9741 the servers obtained a result different from the local build.
9743 @cindex non-determinism, in package builds
9744 As an example, @code{guix.example.org} always gets a different answer.
9745 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
9746 case of Git. This might indicate that the build process of Git is
9747 non-deterministic, meaning that its output varies as a function of
9748 various things that Guix does not fully control, in spite of building
9749 packages in isolated environments (@pxref{Features}). Most common
9750 sources of non-determinism include the addition of timestamps in build
9751 results, the inclusion of random numbers, and directory listings sorted
9752 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
9755 To find out what is wrong with this Git binary, we can do something along
9756 these lines (@pxref{Invoking guix archive}):
9759 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0 \
9760 | guix archive -x /tmp/git
9761 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
9764 This command shows the difference between the files resulting from the
9765 local build, and the files resulting from the build on
9766 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
9767 diffutils, Comparing and Merging Files}). The @command{diff} command
9768 works great for text files. When binary files differ, a better option
9769 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
9770 visualize differences for all kinds of files.
9772 Once you have done that work, you can tell whether the differences are due
9773 to a non-deterministic build process or to a malicious server. We try
9774 hard to remove sources of non-determinism in packages to make it easier
9775 to verify substitutes, but of course, this is a process that
9776 involves not just Guix, but a large part of the free software community.
9777 In the meantime, @command{guix challenge} is one tool to help address
9780 If you are writing packages for Guix, you are encouraged to check
9781 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
9782 same build result as you did with:
9785 $ guix challenge @var{package}
9789 where @var{package} is a package specification such as
9790 @code{guile@@2.0} or @code{glibc:debug}.
9792 The general syntax is:
9795 guix challenge @var{options} [@var{packages}@dots{}]
9798 When a difference is found between the hash of a locally-built item and
9799 that of a server-provided substitute, or among substitutes provided by
9800 different servers, the command displays it as in the example above and
9801 its exit code is 2 (other non-zero exit codes denote other kinds of
9804 The one option that matters is:
9808 @item --substitute-urls=@var{urls}
9809 Consider @var{urls} the whitespace-separated list of substitute source
9814 Show details about matches (identical contents) in addition to
9815 information about mismatches.
9819 @node Invoking guix copy
9820 @section Invoking @command{guix copy}
9822 @cindex copy, of store items, over SSH
9823 @cindex SSH, copy of store items
9824 @cindex sharing store items across machines
9825 @cindex transferring store items across machines
9826 The @command{guix copy} command copies items from the store of one
9827 machine to that of another machine over a secure shell (SSH)
9828 connection@footnote{This command is available only when Guile-SSH was
9829 found. @xref{Requirements}, for details.}. For example, the following
9830 command copies the @code{coreutils} package, the user's profile, and all
9831 their dependencies over to @var{host}, logged in as @var{user}:
9834 guix copy --to=@var{user}@@@var{host} \
9835 coreutils `readlink -f ~/.guix-profile`
9838 If some of the items to be copied are already present on @var{host},
9839 they are not actually sent.
9841 The command below retrieves @code{libreoffice} and @code{gimp} from
9842 @var{host}, assuming they are available there:
9845 guix copy --from=@var{host} libreoffice gimp
9848 The SSH connection is established using the Guile-SSH client, which is
9849 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
9850 @file{~/.ssh/config}, and uses the SSH agent for authentication.
9852 The key used to sign items that are sent must be accepted by the remote
9853 machine. Likewise, the key used by the remote machine to sign items you
9854 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
9855 own daemon. @xref{Invoking guix archive}, for more information about
9856 store item authentication.
9858 The general syntax is:
9861 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
9864 You must always specify one of the following options:
9867 @item --to=@var{spec}
9868 @itemx --from=@var{spec}
9869 Specify the host to send to or receive from. @var{spec} must be an SSH
9870 spec such as @code{example.org}, @code{charlie@@example.org}, or
9871 @code{charlie@@example.org:2222}.
9874 The @var{items} can be either package names, such as @code{gimp}, or
9875 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
9877 When specifying the name of a package to send, it is first built if
9878 needed, unless @option{--dry-run} was specified. Common build options
9879 are supported (@pxref{Common Build Options}).
9882 @node Invoking guix container
9883 @section Invoking @command{guix container}
9885 @cindex @command{guix container}
9887 As of version @value{VERSION}, this tool is experimental. The interface
9888 is subject to radical change in the future.
9891 The purpose of @command{guix container} is to manipulate processes
9892 running within an isolated environment, commonly known as a
9893 ``container'', typically created by the @command{guix environment}
9894 (@pxref{Invoking guix environment}) and @command{guix system container}
9895 (@pxref{Invoking guix system}) commands.
9897 The general syntax is:
9900 guix container @var{action} @var{options}@dots{}
9903 @var{action} specifies the operation to perform with a container, and
9904 @var{options} specifies the context-specific arguments for the action.
9906 The following actions are available:
9910 Execute a command within the context of a running container.
9915 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
9918 @var{pid} specifies the process ID of the running container.
9919 @var{program} specifies an executable file name within the root file
9920 system of the container. @var{arguments} are the additional options that
9921 will be passed to @var{program}.
9923 The following command launches an interactive login shell inside a
9924 Guix system container, started by @command{guix system container}, and whose
9928 guix container exec 9001 /run/current-system/profile/bin/bash --login
9931 Note that the @var{pid} cannot be the parent process of a container. It
9932 must be PID 1 of the container or one of its child processes.
9936 @node Invoking guix weather
9937 @section Invoking @command{guix weather}
9939 Occasionally you're grumpy because substitutes are lacking and you end
9940 up building packages by yourself (@pxref{Substitutes}). The
9941 @command{guix weather} command reports on substitute availability on the
9942 specified servers so you can have an idea of whether you'll be grumpy
9943 today. It can sometimes be useful info as a user, but it is primarily
9944 useful to people running @command{guix publish} (@pxref{Invoking guix
9947 @cindex statistics, for substitutes
9948 @cindex availability of substitutes
9949 @cindex substitute availability
9950 @cindex weather, substitute availability
9951 Here's a sample run:
9954 $ guix weather --substitute-urls=https://guix.example.org
9955 computing 5,872 package derivations for x86_64-linux...
9956 looking for 6,128 store items on https://guix.example.org..
9957 updating list of substitutes from 'https://guix.example.org'... 100.0%
9958 https://guix.example.org
9959 43.4% substitutes available (2,658 out of 6,128)
9960 7,032.5 MiB of nars (compressed)
9961 19,824.2 MiB on disk (uncompressed)
9962 0.030 seconds per request (182.9 seconds in total)
9963 33.5 requests per second
9965 9.8% (342 out of 3,470) of the missing items are queued
9967 x86_64-linux: 518 (59.7%)
9968 i686-linux: 221 (25.5%)
9969 aarch64-linux: 128 (14.8%)
9970 build rate: 23.41 builds per hour
9971 x86_64-linux: 11.16 builds per hour
9972 i686-linux: 6.03 builds per hour
9973 aarch64-linux: 6.41 builds per hour
9976 @cindex continuous integration, statistics
9977 As you can see, it reports the fraction of all the packages for which
9978 substitutes are available on the server---regardless of whether
9979 substitutes are enabled, and regardless of whether this server's signing
9980 key is authorized. It also reports the size of the compressed archives
9981 (``nars'') provided by the server, the size the corresponding store
9982 items occupy in the store (assuming deduplication is turned off), and
9983 the server's throughput. The second part gives continuous integration
9984 (CI) statistics, if the server supports it. In addition, using the
9985 @option{--coverage} option, @command{guix weather} can list ``important''
9986 package substitutes missing on the server (see below).
9988 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
9989 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
9990 challenge}, it ignores signatures on those substitutes, which is
9991 innocuous since the command only gathers statistics and cannot install
9994 Among other things, it is possible to query specific system types and
9995 specific package sets. The available options are listed below.
9998 @item --substitute-urls=@var{urls}
9999 @var{urls} is the space-separated list of substitute server URLs to
10000 query. When this option is omitted, the default set of substitute
10001 servers is queried.
10003 @item --system=@var{system}
10004 @itemx -s @var{system}
10005 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
10006 option can be repeated, in which case @command{guix weather} will query
10007 substitutes for several system types.
10009 @item --manifest=@var{file}
10010 Instead of querying substitutes for all the packages, only ask for those
10011 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
10012 with the @code{-m} option of @command{guix package} (@pxref{Invoking
10015 @item --coverage[=@var{count}]
10016 @itemx -c [@var{count}]
10017 Report on substitute coverage for packages: list packages with at least
10018 @var{count} dependents (zero by default) for which substitutes are
10019 unavailable. Dependent packages themselves are not listed: if @var{b} depends
10020 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
10021 @var{b} usually lacks substitutes as well. The result looks like this:
10024 $ guix weather --substitute-urls=https://ci.guix.info -c 10
10025 computing 8,983 package derivations for x86_64-linux...
10026 looking for 9,343 store items on https://ci.guix.info...
10027 updating substitutes from 'https://ci.guix.info'... 100.0%
10028 https://ci.guix.info
10029 64.7% substitutes available (6,047 out of 9,343)
10031 2502 packages are missing from 'https://ci.guix.info' for 'x86_64-linux', among which:
10032 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
10033 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
10034 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
10038 What this example shows is that @code{kcoreaddons} and presumably the 58
10039 packages that depend on it have no substitutes at @code{ci.guix.info};
10040 likewise for @code{qgpgme} and the 46 packages that depend on it.
10042 If you are a Guix developer, or if you are taking care of this build farm,
10043 you'll probably want to have a closer look at these packages: they may simply
10047 @node Invoking guix processes
10048 @section Invoking @command{guix processes}
10050 The @command{guix processes} command can be useful to developers and system
10051 administrators, especially on multi-user machines and on build farms: it lists
10052 the current sessions (connections to the daemon), as well as information about
10053 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
10054 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
10055 listed.}. Here's an example of the information it returns:
10058 $ sudo guix processes
10061 ClientCommand: guix environment --ad-hoc python
10065 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
10069 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10070 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
10071 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
10072 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
10073 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
10074 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
10075 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
10078 In this example we see that @command{guix-daemon} has three clients:
10079 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
10080 integration tool; their process identifier (PID) is given by the
10081 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
10082 @command{guix-daemon} sub-process of this particular session.
10084 The @code{LockHeld} fields show which store items are currently locked by this
10085 session, which corresponds to store items being built or substituted (the
10086 @code{LockHeld} field is not displayed when @command{guix processes} is not
10087 running as root.) Last, by looking at the @code{ChildProcess} field, we
10088 understand that these three builds are being offloaded (@pxref{Daemon Offload
10091 The output is in Recutils format so we can use the handy @command{recsel}
10092 command to select sessions of interest (@pxref{Selection Expressions,,,
10093 recutils, GNU recutils manual}). As an example, the command shows the command
10094 line and PID of the client that triggered the build of a Perl package:
10097 $ sudo guix processes | \
10098 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
10100 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10104 @node System Configuration
10105 @chapter System Configuration
10107 @cindex system configuration
10108 The Guix System Distribution supports a consistent whole-system configuration
10109 mechanism. By that we mean that all aspects of the global system
10110 configuration---such as the available system services, timezone and
10111 locale settings, user accounts---are declared in a single place. Such
10112 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
10114 One of the advantages of putting all the system configuration under the
10115 control of Guix is that it supports transactional system upgrades, and
10116 makes it possible to roll back to a previous system instantiation,
10117 should something go wrong with the new one (@pxref{Features}). Another
10118 advantage is that it makes it easy to replicate the exact same configuration
10119 across different machines, or at different points in time, without
10120 having to resort to additional administration tools layered on top of
10121 the own tools of the system.
10122 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
10124 This section describes this mechanism. First we focus on the system
10125 administrator's viewpoint---explaining how the system is configured and
10126 instantiated. Then we show how this mechanism can be extended, for
10127 instance to support new system services.
10130 * Using the Configuration System:: Customizing your GNU system.
10131 * operating-system Reference:: Detail of operating-system declarations.
10132 * File Systems:: Configuring file system mounts.
10133 * Mapped Devices:: Block device extra processing.
10134 * User Accounts:: Specifying user accounts.
10135 * Locales:: Language and cultural convention settings.
10136 * Services:: Specifying system services.
10137 * Setuid Programs:: Programs running with root privileges.
10138 * X.509 Certificates:: Authenticating HTTPS servers.
10139 * Name Service Switch:: Configuring libc's name service switch.
10140 * Initial RAM Disk:: Linux-Libre bootstrapping.
10141 * Bootloader Configuration:: Configuring the boot loader.
10142 * Invoking guix system:: Instantiating a system configuration.
10143 * Running Guix in a VM:: How to run Guix System in a virtual machine.
10144 * Defining Services:: Adding new service definitions.
10147 @node Using the Configuration System
10148 @section Using the Configuration System
10150 The operating system is configured by providing an
10151 @code{operating-system} declaration in a file that can then be passed to
10152 the @command{guix system} command (@pxref{Invoking guix system}). A
10153 simple setup, with the default system services, the default Linux-Libre
10154 kernel, initial RAM disk, and boot loader looks like this:
10156 @findex operating-system
10158 @include os-config-bare-bones.texi
10161 This example should be self-describing. Some of the fields defined
10162 above, such as @code{host-name} and @code{bootloader}, are mandatory.
10163 Others, such as @code{packages} and @code{services}, can be omitted, in
10164 which case they get a default value.
10166 Below we discuss the effect of some of the most important fields
10167 (@pxref{operating-system Reference}, for details about all the available
10168 fields), and how to @dfn{instantiate} the operating system using
10169 @command{guix system}.
10171 @unnumberedsubsec Bootloader
10173 @cindex legacy boot, on Intel machines
10174 @cindex BIOS boot, on Intel machines
10177 The @code{bootloader} field describes the method that will be used to boot
10178 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
10179 mode, as in the example above. However, more recent machines rely instead on
10180 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
10181 the @code{bootloader} field should contain something along these lines:
10184 (bootloader-configuration
10185 (bootloader grub-efi-bootloader)
10186 (target "/boot/efi"))
10189 @xref{Bootloader Configuration}, for more information on the available
10190 configuration options.
10192 @unnumberedsubsec Globally-Visible Packages
10194 @vindex %base-packages
10195 The @code{packages} field lists packages that will be globally visible
10196 on the system, for all user accounts---i.e., in every user's @code{PATH}
10197 environment variable---in addition to the per-user profiles
10198 (@pxref{Invoking guix package}). The @var{%base-packages} variable
10199 provides all the tools one would expect for basic user and administrator
10200 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
10201 the GNU Zile lightweight text editor, @command{find}, @command{grep},
10202 etc. The example above adds GNU@tie{}Screen to those,
10203 taken from the @code{(gnu packages screen)}
10204 module (@pxref{Package Modules}). The
10205 @code{(list package output)} syntax can be used to add a specific output
10209 (use-modules (gnu packages))
10210 (use-modules (gnu packages dns))
10214 (packages (cons (list bind "utils")
10218 @findex specification->package
10219 Referring to packages by variable name, like @code{bind} above, has
10220 the advantage of being unambiguous; it also allows typos and such to be
10221 diagnosed right away as ``unbound variables''. The downside is that one
10222 needs to know which module defines which package, and to augment the
10223 @code{use-package-modules} line accordingly. To avoid that, one can use
10224 the @code{specification->package} procedure of the @code{(gnu packages)}
10225 module, which returns the best package for a given name or name and
10229 (use-modules (gnu packages))
10233 (packages (append (map specification->package
10234 '("tcpdump" "htop" "gnupg@@2.0"))
10238 @unnumberedsubsec System Services
10241 @vindex %base-services
10242 The @code{services} field lists @dfn{system services} to be made
10243 available when the system starts (@pxref{Services}).
10244 The @code{operating-system} declaration above specifies that, in
10245 addition to the basic services, we want the OpenSSH secure shell
10246 daemon listening on port 2222 (@pxref{Networking Services,
10247 @code{openssh-service-type}}). Under the hood,
10248 @code{openssh-service-type} arranges so that @command{sshd} is started with the
10249 right command-line options, possibly with supporting configuration files
10250 generated as needed (@pxref{Defining Services}).
10252 @cindex customization, of services
10253 @findex modify-services
10254 Occasionally, instead of using the base services as is, you will want to
10255 customize them. To do this, use @code{modify-services} (@pxref{Service
10256 Reference, @code{modify-services}}) to modify the list.
10258 For example, suppose you want to modify @code{guix-daemon} and Mingetty
10259 (the console log-in) in the @var{%base-services} list (@pxref{Base
10260 Services, @code{%base-services}}). To do that, you can write the
10261 following in your operating system declaration:
10264 (define %my-services
10265 ;; My very own list of services.
10266 (modify-services %base-services
10267 (guix-service-type config =>
10268 (guix-configuration
10270 (use-substitutes? #f)
10271 (extra-options '("--gc-keep-derivations"))))
10272 (mingetty-service-type config =>
10273 (mingetty-configuration
10274 (inherit config)))))
10278 (services %my-services))
10281 This changes the configuration---i.e., the service parameters---of the
10282 @code{guix-service-type} instance, and that of all the
10283 @code{mingetty-service-type} instances in the @var{%base-services} list.
10284 Observe how this is accomplished: first, we arrange for the original
10285 configuration to be bound to the identifier @code{config} in the
10286 @var{body}, and then we write the @var{body} so that it evaluates to the
10287 desired configuration. In particular, notice how we use @code{inherit}
10288 to create a new configuration which has the same values as the old
10289 configuration, but with a few modifications.
10291 @cindex encrypted disk
10292 The configuration for a typical ``desktop'' usage, with an encrypted
10293 root partition, the X11 display
10294 server, GNOME and Xfce (users can choose which of these desktop
10295 environments to use at the log-in screen by pressing @kbd{F1}), network
10296 management, power management, and more, would look like this:
10299 @include os-config-desktop.texi
10302 A graphical system with a choice of lightweight window managers
10303 instead of full-blown desktop environments would look like this:
10306 @include os-config-lightweight-desktop.texi
10309 This example refers to the @file{/boot/efi} file system by its UUID,
10310 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
10311 as returned by the @command{blkid} command.
10313 @xref{Desktop Services}, for the exact list of services provided by
10314 @var{%desktop-services}. @xref{X.509 Certificates}, for background
10315 information about the @code{nss-certs} package that is used here.
10317 Again, @var{%desktop-services} is just a list of service objects. If
10318 you want to remove services from there, you can do so using the
10319 procedures for list filtering (@pxref{SRFI-1 Filtering and
10320 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
10321 following expression returns a list that contains all the services in
10322 @var{%desktop-services} minus the Avahi service:
10325 (remove (lambda (service)
10326 (eq? (service-kind service) avahi-service-type))
10330 @unnumberedsubsec Instantiating the System
10332 Assuming the @code{operating-system} declaration
10333 is stored in the @file{my-system-config.scm}
10334 file, the @command{guix system reconfigure my-system-config.scm} command
10335 instantiates that configuration, and makes it the default GRUB boot
10336 entry (@pxref{Invoking guix system}).
10338 The normal way to change the system configuration is by updating this
10339 file and re-running @command{guix system reconfigure}. One should never
10340 have to touch files in @file{/etc} or to run commands that modify the
10341 system state such as @command{useradd} or @command{grub-install}. In
10342 fact, you must avoid that since that would not only void your warranty
10343 but also prevent you from rolling back to previous versions of your
10344 system, should you ever need to.
10346 @cindex roll-back, of the operating system
10347 Speaking of roll-back, each time you run @command{guix system
10348 reconfigure}, a new @dfn{generation} of the system is created---without
10349 modifying or deleting previous generations. Old system generations get
10350 an entry in the bootloader boot menu, allowing you to boot them in case
10351 something went wrong with the latest generation. Reassuring, no? The
10352 @command{guix system list-generations} command lists the system
10353 generations available on disk. It is also possible to roll back the
10354 system via the commands @command{guix system roll-back} and
10355 @command{guix system switch-generation}.
10357 Although the @command{guix system reconfigure} command will not modify
10358 previous generations, you must take care when the current generation is not
10359 the latest (e.g., after invoking @command{guix system roll-back}), since
10360 the operation might overwrite a later generation (@pxref{Invoking guix
10363 @unnumberedsubsec The Programming Interface
10365 At the Scheme level, the bulk of an @code{operating-system} declaration
10366 is instantiated with the following monadic procedure (@pxref{The Store
10369 @deffn {Monadic Procedure} operating-system-derivation os
10370 Return a derivation that builds @var{os}, an @code{operating-system}
10371 object (@pxref{Derivations}).
10373 The output of the derivation is a single directory that refers to all
10374 the packages, configuration files, and other supporting files needed to
10375 instantiate @var{os}.
10378 This procedure is provided by the @code{(gnu system)} module. Along
10379 with @code{(gnu services)} (@pxref{Services}), this module contains the
10380 guts of Guix System. Make sure to visit it!
10383 @node operating-system Reference
10384 @section @code{operating-system} Reference
10386 This section summarizes all the options available in
10387 @code{operating-system} declarations (@pxref{Using the Configuration
10390 @deftp {Data Type} operating-system
10391 This is the data type representing an operating system configuration.
10392 By that, we mean all the global system configuration, not per-user
10393 configuration (@pxref{Using the Configuration System}).
10396 @item @code{kernel} (default: @var{linux-libre})
10397 The package object of the operating system kernel to use@footnote{Currently
10398 only the Linux-libre kernel is supported. In the future, it will be
10399 possible to use the GNU@tie{}Hurd.}.
10401 @item @code{kernel-arguments} (default: @code{'()})
10402 List of strings or gexps representing additional arguments to pass on
10403 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
10405 @item @code{bootloader}
10406 The system bootloader configuration object. @xref{Bootloader Configuration}.
10408 @item @code{keyboard-layout} (default: @code{#f})
10409 This field specifies the keyboard layout to use in the console. It can be
10410 either @code{#f}, in which case the default keyboard layout is used (usually
10411 US English), or a @code{<keyboard-layout>} record.
10413 This keyboard layout is in effect as soon as the kernel has booted. For
10414 instance, it is the keyboard layout in effect when you type a passphrase if
10415 your root file system is on a @code{luks-device-mapping} mapped device
10416 (@pxref{Mapped Devices}).
10419 This does @emph{not} specify the keyboard layout used by the bootloader, nor
10420 that used by the graphical display server. @xref{Bootloader Configuration},
10421 for information on how to specify the bootloader's keyboard layout. @xref{X
10422 Window}, for information on how to specify the keyboard layout used by the X
10426 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
10428 @cindex initial RAM disk
10429 The list of Linux kernel modules that need to be available in the
10430 initial RAM disk. @xref{Initial RAM Disk}.
10432 @item @code{initrd} (default: @code{base-initrd})
10433 A procedure that returns an initial RAM disk for the Linux
10434 kernel. This field is provided to support low-level customization and
10435 should rarely be needed for casual use. @xref{Initial RAM Disk}.
10437 @item @code{firmware} (default: @var{%base-firmware})
10439 List of firmware packages loadable by the operating system kernel.
10441 The default includes firmware needed for Atheros- and Broadcom-based
10442 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
10443 respectively). @xref{Hardware Considerations}, for more info on
10444 supported hardware.
10446 @item @code{host-name}
10449 @item @code{hosts-file}
10451 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
10452 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
10453 Reference Manual}). The default is a file with entries for
10454 @code{localhost} and @var{host-name}.
10456 @item @code{mapped-devices} (default: @code{'()})
10457 A list of mapped devices. @xref{Mapped Devices}.
10459 @item @code{file-systems}
10460 A list of file systems. @xref{File Systems}.
10462 @item @code{swap-devices} (default: @code{'()})
10463 @cindex swap devices
10464 A list of strings identifying devices or files to be used for ``swap
10465 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
10466 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
10467 It is possible to specify a swap file in a file system on a mapped
10468 device, provided that the necessary device mapping and file system are
10469 also specified. @xref{Mapped Devices} and @ref{File Systems}.
10471 @item @code{users} (default: @code{%base-user-accounts})
10472 @itemx @code{groups} (default: @var{%base-groups})
10473 List of user accounts and groups. @xref{User Accounts}.
10475 If the @code{users} list lacks a user account with UID@tie{}0, a
10476 ``root'' account with UID@tie{}0 is automatically added.
10478 @item @code{skeletons} (default: @code{(default-skeletons)})
10479 A list target file name/file-like object tuples (@pxref{G-Expressions,
10480 file-like objects}). These are the skeleton files that will be added to
10481 the home directory of newly-created user accounts.
10483 For instance, a valid value may look like this:
10486 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
10487 (".guile" ,(plain-file "guile"
10488 "(use-modules (ice-9 readline))
10489 (activate-readline)")))
10492 @item @code{issue} (default: @var{%default-issue})
10493 A string denoting the contents of the @file{/etc/issue} file, which is
10494 displayed when users log in on a text console.
10496 @item @code{packages} (default: @var{%base-packages})
10497 The set of packages installed in the global profile, which is accessible
10498 at @file{/run/current-system/profile}.
10500 The default set includes core utilities and it is good practice to
10501 install non-core utilities in user profiles (@pxref{Invoking guix
10504 @item @code{timezone}
10505 A timezone identifying string---e.g., @code{"Europe/Paris"}.
10507 You can run the @command{tzselect} command to find out which timezone
10508 string corresponds to your region. Choosing an invalid timezone name
10509 causes @command{guix system} to fail.
10511 @item @code{locale} (default: @code{"en_US.utf8"})
10512 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
10513 Library Reference Manual}). @xref{Locales}, for more information.
10515 @item @code{locale-definitions} (default: @var{%default-locale-definitions})
10516 The list of locale definitions to be compiled and that may be used at
10517 run time. @xref{Locales}.
10519 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
10520 The list of GNU@tie{}libc packages whose locale data and tools are used
10521 to build the locale definitions. @xref{Locales}, for compatibility
10522 considerations that justify this option.
10524 @item @code{name-service-switch} (default: @var{%default-nss})
10525 Configuration of the libc name service switch (NSS)---a
10526 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
10529 @item @code{services} (default: @var{%base-services})
10530 A list of service objects denoting system services. @xref{Services}.
10532 @item @code{pam-services} (default: @code{(base-pam-services)})
10534 @cindex pluggable authentication modules
10535 Linux @dfn{pluggable authentication module} (PAM) services.
10536 @c FIXME: Add xref to PAM services section.
10538 @item @code{setuid-programs} (default: @var{%setuid-programs})
10539 List of string-valued G-expressions denoting setuid programs.
10540 @xref{Setuid Programs}.
10542 @item @code{sudoers-file} (default: @var{%sudoers-specification})
10543 @cindex sudoers file
10544 The contents of the @file{/etc/sudoers} file as a file-like object
10545 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
10547 This file specifies which users can use the @command{sudo} command, what
10548 they are allowed to do, and what privileges they may gain. The default
10549 is that only @code{root} and members of the @code{wheel} group may use
10556 @section File Systems
10558 The list of file systems to be mounted is specified in the
10559 @code{file-systems} field of the operating system declaration
10560 (@pxref{Using the Configuration System}). Each file system is declared
10561 using the @code{file-system} form, like this:
10565 (mount-point "/home")
10566 (device "/dev/sda3")
10570 As usual, some of the fields are mandatory---those shown in the example
10571 above---while others can be omitted. These are described below.
10573 @deftp {Data Type} file-system
10574 Objects of this type represent file systems to be mounted. They
10575 contain the following members:
10579 This is a string specifying the type of the file system---e.g.,
10582 @item @code{mount-point}
10583 This designates the place where the file system is to be mounted.
10585 @item @code{device}
10586 This names the ``source'' of the file system. It can be one of three
10587 things: a file system label, a file system UUID, or the name of a
10588 @file{/dev} node. Labels and UUIDs offer a way to refer to file
10589 systems without having to hard-code their actual device
10590 name@footnote{Note that, while it is tempting to use
10591 @file{/dev/disk/by-uuid} and similar device names to achieve the same
10592 result, this is not recommended: These special device nodes are created
10593 by the udev daemon and may be unavailable at the time the device is
10596 @findex file-system-label
10597 File system labels are created using the @code{file-system-label}
10598 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
10599 plain strings. Here's an example of a file system referred to by its
10600 label, as shown by the @command{e2label} command:
10604 (mount-point "/home")
10606 (device (file-system-label "my-home")))
10610 UUIDs are converted from their string representation (as shown by the
10611 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
10612 @code{uuid} form expects 16-byte UUIDs as defined in
10613 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
10614 form of UUID used by the ext2 family of file systems and others, but it
10615 is different from ``UUIDs'' found in FAT file systems, for instance.},
10620 (mount-point "/home")
10622 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
10625 When the source of a file system is a mapped device (@pxref{Mapped
10626 Devices}), its @code{device} field @emph{must} refer to the mapped
10627 device name---e.g., @file{"/dev/mapper/root-partition"}.
10628 This is required so that
10629 the system knows that mounting the file system depends on having the
10630 corresponding device mapping established.
10632 @item @code{flags} (default: @code{'()})
10633 This is a list of symbols denoting mount flags. Recognized flags
10634 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
10635 access to special files), @code{no-suid} (ignore setuid and setgid
10636 bits), and @code{no-exec} (disallow program execution.)
10638 @item @code{options} (default: @code{#f})
10639 This is either @code{#f}, or a string denoting mount options.
10641 @item @code{mount?} (default: @code{#t})
10642 This value indicates whether to automatically mount the file system when
10643 the system is brought up. When set to @code{#f}, the file system gets
10644 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
10645 is not automatically mounted.
10647 @item @code{needed-for-boot?} (default: @code{#f})
10648 This Boolean value indicates whether the file system is needed when
10649 booting. If that is true, then the file system is mounted when the
10650 initial RAM disk (initrd) is loaded. This is always the case, for
10651 instance, for the root file system.
10653 @item @code{check?} (default: @code{#t})
10654 This Boolean indicates whether the file system needs to be checked for
10655 errors before being mounted.
10657 @item @code{create-mount-point?} (default: @code{#f})
10658 When true, the mount point is created if it does not exist yet.
10660 @item @code{dependencies} (default: @code{'()})
10661 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
10662 representing file systems that must be mounted or mapped devices that
10663 must be opened before (and unmounted or closed after) this one.
10665 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
10666 a dependency of @file{/sys/fs/cgroup/cpu} and
10667 @file{/sys/fs/cgroup/memory}.
10669 Another example is a file system that depends on a mapped device, for
10670 example for an encrypted partition (@pxref{Mapped Devices}).
10674 The @code{(gnu system file-systems)} exports the following useful
10677 @defvr {Scheme Variable} %base-file-systems
10678 These are essential file systems that are required on normal systems,
10679 such as @var{%pseudo-terminal-file-system} and @var{%immutable-store} (see
10680 below.) Operating system declarations should always contain at least
10684 @defvr {Scheme Variable} %pseudo-terminal-file-system
10685 This is the file system to be mounted as @file{/dev/pts}. It supports
10686 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
10687 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
10688 Manual}). Pseudo-terminals are used by terminal emulators such as
10692 @defvr {Scheme Variable} %shared-memory-file-system
10693 This file system is mounted as @file{/dev/shm} and is used to support
10694 memory sharing across processes (@pxref{Memory-mapped I/O,
10695 @code{shm_open},, libc, The GNU C Library Reference Manual}).
10698 @defvr {Scheme Variable} %immutable-store
10699 This file system performs a read-only ``bind mount'' of
10700 @file{/gnu/store}, making it read-only for all the users including
10701 @code{root}. This prevents against accidental modification by software
10702 running as @code{root} or by system administrators.
10704 The daemon itself is still able to write to the store: it remounts it
10705 read-write in its own ``name space.''
10708 @defvr {Scheme Variable} %binary-format-file-system
10709 The @code{binfmt_misc} file system, which allows handling of arbitrary
10710 executable file types to be delegated to user space. This requires the
10711 @code{binfmt.ko} kernel module to be loaded.
10714 @defvr {Scheme Variable} %fuse-control-file-system
10715 The @code{fusectl} file system, which allows unprivileged users to mount
10716 and unmount user-space FUSE file systems. This requires the
10717 @code{fuse.ko} kernel module to be loaded.
10720 @node Mapped Devices
10721 @section Mapped Devices
10723 @cindex device mapping
10724 @cindex mapped devices
10725 The Linux kernel has a notion of @dfn{device mapping}: a block device,
10726 such as a hard disk partition, can be @dfn{mapped} into another device,
10727 usually in @code{/dev/mapper/},
10728 with additional processing over the data that flows through
10729 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
10730 concept of a ``mapped device'' and that of a file system: both boil down
10731 to @emph{translating} input/output operations made on a file to
10732 operations on its backing store. Thus, the Hurd implements mapped
10733 devices, like file systems, using the generic @dfn{translator} mechanism
10734 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
10735 typical example is encryption device mapping: all writes to the mapped
10736 device are encrypted, and all reads are deciphered, transparently.
10737 Guix extends this notion by considering any device or set of devices that
10738 are @dfn{transformed} in some way to create a new device; for instance,
10739 RAID devices are obtained by @dfn{assembling} several other devices, such
10740 as hard disks or partitions, into a new one that behaves as one partition.
10741 Other examples, not yet implemented, are LVM logical volumes.
10743 Mapped devices are declared using the @code{mapped-device} form,
10744 defined as follows; for examples, see below.
10746 @deftp {Data Type} mapped-device
10747 Objects of this type represent device mappings that will be made when
10748 the system boots up.
10752 This is either a string specifying the name of the block device to be mapped,
10753 such as @code{"/dev/sda3"}, or a list of such strings when several devices
10754 need to be assembled for creating a new one.
10757 This string specifies the name of the resulting mapped device. For
10758 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
10759 specifying @code{"my-partition"} leads to the creation of
10760 the @code{"/dev/mapper/my-partition"} device.
10761 For RAID devices of type @code{raid-device-mapping}, the full device name
10762 such as @code{"/dev/md0"} needs to be given.
10765 This must be a @code{mapped-device-kind} object, which specifies how
10766 @var{source} is mapped to @var{target}.
10770 @defvr {Scheme Variable} luks-device-mapping
10771 This defines LUKS block device encryption using the @command{cryptsetup}
10772 command from the package with the same name. It relies on the
10773 @code{dm-crypt} Linux kernel module.
10776 @defvr {Scheme Variable} raid-device-mapping
10777 This defines a RAID device, which is assembled using the @code{mdadm}
10778 command from the package with the same name. It requires a Linux kernel
10779 module for the appropriate RAID level to be loaded, such as @code{raid456}
10780 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
10783 @cindex disk encryption
10785 The following example specifies a mapping from @file{/dev/sda3} to
10786 @file{/dev/mapper/home} using LUKS---the
10787 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
10788 standard mechanism for disk encryption.
10789 The @file{/dev/mapper/home}
10790 device can then be used as the @code{device} of a @code{file-system}
10791 declaration (@pxref{File Systems}).
10795 (source "/dev/sda3")
10797 (type luks-device-mapping))
10800 Alternatively, to become independent of device numbering, one may obtain
10801 the LUKS UUID (@dfn{unique identifier}) of the source device by a
10805 cryptsetup luksUUID /dev/sda3
10808 and use it as follows:
10812 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
10814 (type luks-device-mapping))
10817 @cindex swap encryption
10818 It is also desirable to encrypt swap space, since swap space may contain
10819 sensitive data. One way to accomplish that is to use a swap file in a
10820 file system on a device mapped via LUKS encryption. In this way, the
10821 swap file is encrypted because the entire device is encrypted.
10822 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
10824 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
10825 may be declared as follows:
10829 (source (list "/dev/sda1" "/dev/sdb1"))
10830 (target "/dev/md0")
10831 (type raid-device-mapping))
10834 The @file{/dev/md0} device can then be used as the @code{device} of a
10835 @code{file-system} declaration (@pxref{File Systems}).
10836 Note that the RAID level need not be given; it is chosen during the
10837 initial creation and formatting of the RAID device and is determined
10838 automatically later.
10841 @node User Accounts
10842 @section User Accounts
10846 @cindex user accounts
10847 User accounts and groups are entirely managed through the
10848 @code{operating-system} declaration. They are specified with the
10849 @code{user-account} and @code{user-group} forms:
10855 (supplementary-groups '("wheel" ;allow use of sudo, etc.
10856 "audio" ;sound card
10857 "video" ;video devices such as webcams
10858 "cdrom")) ;the good ol' CD-ROM
10859 (comment "Bob's sister")
10860 (home-directory "/home/alice"))
10863 When booting or upon completion of @command{guix system reconfigure},
10864 the system ensures that only the user accounts and groups specified in
10865 the @code{operating-system} declaration exist, and with the specified
10866 properties. Thus, account or group creations or modifications made by
10867 directly invoking commands such as @command{useradd} are lost upon
10868 reconfiguration or reboot. This ensures that the system remains exactly
10871 @deftp {Data Type} user-account
10872 Objects of this type represent user accounts. The following members may
10877 The name of the user account.
10881 This is the name (a string) or identifier (a number) of the user group
10882 this account belongs to.
10884 @item @code{supplementary-groups} (default: @code{'()})
10885 Optionally, this can be defined as a list of group names that this
10886 account belongs to.
10888 @item @code{uid} (default: @code{#f})
10889 This is the user ID for this account (a number), or @code{#f}. In the
10890 latter case, a number is automatically chosen by the system when the
10891 account is created.
10893 @item @code{comment} (default: @code{""})
10894 A comment about the account, such as the account owner's full name.
10896 @item @code{home-directory}
10897 This is the name of the home directory for the account.
10899 @item @code{create-home-directory?} (default: @code{#t})
10900 Indicates whether the home directory of this account should be created
10901 if it does not exist yet.
10903 @item @code{shell} (default: Bash)
10904 This is a G-expression denoting the file name of a program to be used as
10905 the shell (@pxref{G-Expressions}).
10907 @item @code{system?} (default: @code{#f})
10908 This Boolean value indicates whether the account is a ``system''
10909 account. System accounts are sometimes treated specially; for instance,
10910 graphical login managers do not list them.
10912 @anchor{user-account-password}
10913 @cindex password, for user accounts
10914 @item @code{password} (default: @code{#f})
10915 You would normally leave this field to @code{#f}, initialize user
10916 passwords as @code{root} with the @command{passwd} command, and then let
10917 users change it with @command{passwd}. Passwords set with
10918 @command{passwd} are of course preserved across reboot and
10921 If you @emph{do} want to set an initial password for an account, then
10922 this field must contain the encrypted password, as a string. You can use the
10923 @code{crypt} procedure for this purpose:
10928 (home-directory "/home/charlie")
10931 ;; Specify a SHA-512-hashed initial password.
10932 (password (crypt "InitialPassword!" "$6$abc")))
10936 The hash of this initial password will be available in a file in
10937 @file{/gnu/store}, readable by all the users, so this method must be used with
10941 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
10942 more information on password encryption, and @ref{Encryption,,, guile, GNU
10943 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
10949 User group declarations are even simpler:
10952 (user-group (name "students"))
10955 @deftp {Data Type} user-group
10956 This type is for, well, user groups. There are just a few fields:
10960 The name of the group.
10962 @item @code{id} (default: @code{#f})
10963 The group identifier (a number). If @code{#f}, a new number is
10964 automatically allocated when the group is created.
10966 @item @code{system?} (default: @code{#f})
10967 This Boolean value indicates whether the group is a ``system'' group.
10968 System groups have low numerical IDs.
10970 @item @code{password} (default: @code{#f})
10971 What, user groups can have a password? Well, apparently yes. Unless
10972 @code{#f}, this field specifies the password of the group.
10977 For convenience, a variable lists all the basic user groups one may
10980 @defvr {Scheme Variable} %base-groups
10981 This is the list of basic user groups that users and/or packages expect
10982 to be present on the system. This includes groups such as ``root'',
10983 ``wheel'', and ``users'', as well as groups used to control access to
10984 specific devices such as ``audio'', ``disk'', and ``cdrom''.
10987 @defvr {Scheme Variable} %base-user-accounts
10988 This is the list of basic system accounts that programs may expect to
10989 find on a GNU/Linux system, such as the ``nobody'' account.
10991 Note that the ``root'' account is not included here. It is a
10992 special-case and is automatically added whether or not it is specified.
10999 A @dfn{locale} defines cultural conventions for a particular language
11000 and region of the world (@pxref{Locales,,, libc, The GNU C Library
11001 Reference Manual}). Each locale has a name that typically has the form
11002 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
11003 @code{fr_LU.utf8} designates the locale for the French language, with
11004 cultural conventions from Luxembourg, and using the UTF-8 encoding.
11006 @cindex locale definition
11007 Usually, you will want to specify the default locale for the machine
11008 using the @code{locale} field of the @code{operating-system} declaration
11009 (@pxref{operating-system Reference, @code{locale}}).
11011 The selected locale is automatically added to the @dfn{locale
11012 definitions} known to the system if needed, with its codeset inferred
11013 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
11014 @code{UTF-8} codeset. Additional locale definitions can be specified in
11015 the @code{locale-definitions} slot of @code{operating-system}---this is
11016 useful, for instance, if the codeset could not be inferred from the
11017 locale name. The default set of locale definitions includes some widely
11018 used locales, but not all the available locales, in order to save space.
11020 For instance, to add the North Frisian locale for Germany, the value of
11024 (cons (locale-definition
11025 (name "fy_DE.utf8") (source "fy_DE"))
11026 %default-locale-definitions)
11029 Likewise, to save space, one might want @code{locale-definitions} to
11030 list only the locales that are actually used, as in:
11033 (list (locale-definition
11034 (name "ja_JP.eucjp") (source "ja_JP")
11035 (charset "EUC-JP")))
11039 The compiled locale definitions are available at
11040 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
11041 version, which is the default location where the GNU@tie{}libc provided
11042 by Guix looks for locale data. This can be overridden using the
11043 @code{LOCPATH} environment variable (@pxref{locales-and-locpath,
11044 @code{LOCPATH} and locale packages}).
11046 The @code{locale-definition} form is provided by the @code{(gnu system
11047 locale)} module. Details are given below.
11049 @deftp {Data Type} locale-definition
11050 This is the data type of a locale definition.
11055 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
11056 Reference Manual}, for more information on locale names.
11058 @item @code{source}
11059 The name of the source for that locale. This is typically the
11060 @code{@var{language}_@var{territory}} part of the locale name.
11062 @item @code{charset} (default: @code{"UTF-8"})
11063 The ``character set'' or ``code set'' for that locale,
11064 @uref{http://www.iana.org/assignments/character-sets, as defined by
11070 @defvr {Scheme Variable} %default-locale-definitions
11071 A list of commonly used UTF-8 locales, used as the default
11072 value of the @code{locale-definitions} field of @code{operating-system}
11075 @cindex locale name
11076 @cindex normalized codeset in locale names
11077 These locale definitions use the @dfn{normalized codeset} for the part
11078 that follows the dot in the name (@pxref{Using gettextized software,
11079 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
11080 instance it has @code{uk_UA.utf8} but @emph{not}, say,
11081 @code{uk_UA.UTF-8}.
11084 @subsection Locale Data Compatibility Considerations
11086 @cindex incompatibility, of locale data
11087 @code{operating-system} declarations provide a @code{locale-libcs} field
11088 to specify the GNU@tie{}libc packages that are used to compile locale
11089 declarations (@pxref{operating-system Reference}). ``Why would I
11090 care?'', you may ask. Well, it turns out that the binary format of
11091 locale data is occasionally incompatible from one libc version to
11094 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
11095 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
11096 For instance, a program linked against libc version 2.21 is unable to
11097 read locale data produced with libc 2.22; worse, that program
11098 @emph{aborts} instead of simply ignoring the incompatible locale
11099 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
11100 the incompatible locale data, which is already an improvement.}.
11101 Similarly, a program linked against libc 2.22 can read most, but not
11102 all, of the locale data from libc 2.21 (specifically, @code{LC_COLLATE}
11103 data is incompatible); thus calls to @code{setlocale} may fail, but
11104 programs will not abort.
11106 The ``problem'' with Guix is that users have a lot of freedom: They can
11107 choose whether and when to upgrade software in their profiles, and might
11108 be using a libc version different from the one the system administrator
11109 used to build the system-wide locale data.
11111 Fortunately, unprivileged users can also install their own locale data
11112 and define @var{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
11113 @code{GUIX_LOCPATH} and locale packages}).
11115 Still, it is best if the system-wide locale data at
11116 @file{/run/current-system/locale} is built for all the libc versions
11117 actually in use on the system, so that all the programs can access
11118 it---this is especially crucial on a multi-user system. To do that, the
11119 administrator can specify several libc packages in the
11120 @code{locale-libcs} field of @code{operating-system}:
11123 (use-package-modules base)
11127 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
11130 This example would lead to a system containing locale definitions for
11131 both libc 2.21 and the current version of libc in
11132 @file{/run/current-system/locale}.
11138 @cindex system services
11139 An important part of preparing an @code{operating-system} declaration is
11140 listing @dfn{system services} and their configuration (@pxref{Using the
11141 Configuration System}). System services are typically daemons launched
11142 when the system boots, or other actions needed at that time---e.g.,
11143 configuring network access.
11145 Guix has a broad definition of ``service'' (@pxref{Service
11146 Composition}), but many services are managed by the GNU@tie{}Shepherd
11147 (@pxref{Shepherd Services}). On a running system, the @command{herd}
11148 command allows you to list the available services, show their status,
11149 start and stop them, or do other specific operations (@pxref{Jump
11150 Start,,, shepherd, The GNU Shepherd Manual}). For example:
11156 The above command, run as @code{root}, lists the currently defined
11157 services. The @command{herd doc} command shows a synopsis of the given
11158 service and its associated actions:
11162 Run libc's name service cache daemon (nscd).
11164 # herd doc nscd action invalidate
11165 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
11168 The @command{start}, @command{stop}, and @command{restart} sub-commands
11169 have the effect you would expect. For instance, the commands below stop
11170 the nscd service and restart the Xorg display server:
11174 Service nscd has been stopped.
11175 # herd restart xorg-server
11176 Service xorg-server has been stopped.
11177 Service xorg-server has been started.
11180 The following sections document the available services, starting with
11181 the core services, that may be used in an @code{operating-system}
11185 * Base Services:: Essential system services.
11186 * Scheduled Job Execution:: The mcron service.
11187 * Log Rotation:: The rottlog service.
11188 * Networking Services:: Network setup, SSH daemon, etc.
11189 * X Window:: Graphical display.
11190 * Printing Services:: Local and remote printer support.
11191 * Desktop Services:: D-Bus and desktop services.
11192 * Sound Services:: ALSA and Pulseaudio services.
11193 * Database Services:: SQL databases, key-value stores, etc.
11194 * Mail Services:: IMAP, POP3, SMTP, and all that.
11195 * Messaging Services:: Messaging services.
11196 * Telephony Services:: Telephony services.
11197 * Monitoring Services:: Monitoring services.
11198 * Kerberos Services:: Kerberos services.
11199 * LDAP Services:: LDAP services.
11200 * Web Services:: Web servers.
11201 * Certificate Services:: TLS certificates via Let's Encrypt.
11202 * DNS Services:: DNS daemons.
11203 * VPN Services:: VPN daemons.
11204 * Network File System:: NFS related services.
11205 * Continuous Integration:: The Cuirass service.
11206 * Power Management Services:: Extending battery life.
11207 * Audio Services:: The MPD.
11208 * Virtualization Services:: Virtualization services.
11209 * Version Control Services:: Providing remote access to Git repositories.
11210 * Game Services:: Game servers.
11211 * Miscellaneous Services:: Other services.
11214 @node Base Services
11215 @subsection Base Services
11217 The @code{(gnu services base)} module provides definitions for the basic
11218 services that one expects from the system. The services exported by
11219 this module are listed below.
11221 @defvr {Scheme Variable} %base-services
11222 This variable contains a list of basic services (@pxref{Service Types
11223 and Services}, for more information on service objects) one would
11224 expect from the system: a login service (mingetty) on each tty, syslogd,
11225 the libc name service cache daemon (nscd), the udev device manager, and
11228 This is the default value of the @code{services} field of
11229 @code{operating-system} declarations. Usually, when customizing a
11230 system, you will want to append services to @var{%base-services}, like
11234 (append (list (service avahi-service-type)
11235 (service openssh-service-type))
11240 @defvr {Scheme Variable} special-files-service-type
11241 This is the service that sets up ``special files'' such as
11242 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
11244 The value associated with @code{special-files-service-type} services
11245 must be a list of tuples where the first element is the ``special file''
11246 and the second element is its target. By default it is:
11248 @cindex @file{/bin/sh}
11249 @cindex @file{sh}, in @file{/bin}
11251 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh")))
11254 @cindex @file{/usr/bin/env}
11255 @cindex @file{env}, in @file{/usr/bin}
11256 If you want to add, say, @code{/usr/bin/env} to your system, you can
11260 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh"))
11261 ("/usr/bin/env" ,(file-append @var{coreutils} "/bin/env")))
11264 Since this is part of @code{%base-services}, you can use
11265 @code{modify-services} to customize the set of special files
11266 (@pxref{Service Reference, @code{modify-services}}). But the simple way
11267 to add a special file is @i{via} the @code{extra-special-file} procedure
11271 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
11272 Use @var{target} as the ``special file'' @var{file}.
11274 For example, adding the following lines to the @code{services} field of
11275 your operating system declaration leads to a @file{/usr/bin/env}
11279 (extra-special-file "/usr/bin/env"
11280 (file-append coreutils "/bin/env"))
11284 @deffn {Scheme Procedure} host-name-service @var{name}
11285 Return a service that sets the host name to @var{name}.
11288 @deffn {Scheme Procedure} login-service @var{config}
11289 Return a service to run login according to @var{config}, a
11290 @code{<login-configuration>} object, which specifies the message of the day,
11291 among other things.
11294 @deftp {Data Type} login-configuration
11295 This is the data type representing the configuration of login.
11300 @cindex message of the day
11301 A file-like object containing the ``message of the day''.
11303 @item @code{allow-empty-passwords?} (default: @code{#t})
11304 Allow empty passwords by default so that first-time users can log in when
11305 the 'root' account has just been created.
11310 @deffn {Scheme Procedure} mingetty-service @var{config}
11311 Return a service to run mingetty according to @var{config}, a
11312 @code{<mingetty-configuration>} object, which specifies the tty to run, among
11316 @deftp {Data Type} mingetty-configuration
11317 This is the data type representing the configuration of Mingetty, which
11318 provides the default implementation of virtual console log-in.
11323 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
11325 @item @code{auto-login} (default: @code{#f})
11326 When true, this field must be a string denoting the user name under
11327 which the system automatically logs in. When it is @code{#f}, a
11328 user name and password must be entered to log in.
11330 @item @code{login-program} (default: @code{#f})
11331 This must be either @code{#f}, in which case the default log-in program
11332 is used (@command{login} from the Shadow tool suite), or a gexp denoting
11333 the name of the log-in program.
11335 @item @code{login-pause?} (default: @code{#f})
11336 When set to @code{#t} in conjunction with @var{auto-login}, the user
11337 will have to press a key before the log-in shell is launched.
11339 @item @code{mingetty} (default: @var{mingetty})
11340 The Mingetty package to use.
11345 @deffn {Scheme Procedure} agetty-service @var{config}
11346 Return a service to run agetty according to @var{config}, an
11347 @code{<agetty-configuration>} object, which specifies the tty to run,
11348 among other things.
11351 @deftp {Data Type} agetty-configuration
11352 This is the data type representing the configuration of agetty, which
11353 implements virtual and serial console log-in. See the @code{agetty(8)}
11354 man page for more information.
11359 The name of the console this agetty runs on, as a string---e.g.,
11360 @code{"ttyS0"}. This argument is optional, it will default to
11361 a reasonable default serial port used by the kernel Linux.
11363 For this, if there is a value for an option @code{agetty.tty} in the kernel
11364 command line, agetty will extract the device name of the serial port
11365 from it and use that.
11367 If not and if there is a value for an option @code{console} with a tty in
11368 the Linux command line, agetty will extract the device name of the
11369 serial port from it and use that.
11371 In both cases, agetty will leave the other serial device settings
11372 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
11375 @item @code{baud-rate} (default: @code{#f})
11376 A string containing a comma-separated list of one or more baud rates, in
11379 @item @code{term} (default: @code{#f})
11380 A string containing the value used for the @code{TERM} environment
11383 @item @code{eight-bits?} (default: @code{#f})
11384 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
11387 @item @code{auto-login} (default: @code{#f})
11388 When passed a login name, as a string, the specified user will be logged
11389 in automatically without prompting for their login name or password.
11391 @item @code{no-reset?} (default: @code{#f})
11392 When @code{#t}, don't reset terminal cflags (control modes).
11394 @item @code{host} (default: @code{#f})
11395 This accepts a string containing the "login_host", which will be written
11396 into the @file{/var/run/utmpx} file.
11398 @item @code{remote?} (default: @code{#f})
11399 When set to @code{#t} in conjunction with @var{host}, this will add an
11400 @code{-r} fakehost option to the command line of the login program
11401 specified in @var{login-program}.
11403 @item @code{flow-control?} (default: @code{#f})
11404 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
11406 @item @code{no-issue?} (default: @code{#f})
11407 When set to @code{#t}, the contents of the @file{/etc/issue} file will
11408 not be displayed before presenting the login prompt.
11410 @item @code{init-string} (default: @code{#f})
11411 This accepts a string that will be sent to the tty or modem before
11412 sending anything else. It can be used to initialize a modem.
11414 @item @code{no-clear?} (default: @code{#f})
11415 When set to @code{#t}, agetty will not clear the screen before showing
11418 @item @code{login-program} (default: (file-append shadow "/bin/login"))
11419 This must be either a gexp denoting the name of a log-in program, or
11420 unset, in which case the default value is the @command{login} from the
11423 @item @code{local-line} (default: @code{#f})
11424 Control the CLOCAL line flag. This accepts one of three symbols as
11425 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
11426 the default value chosen by agetty is @code{'auto}.
11428 @item @code{extract-baud?} (default: @code{#f})
11429 When set to @code{#t}, instruct agetty to try to extract the baud rate
11430 from the status messages produced by certain types of modems.
11432 @item @code{skip-login?} (default: @code{#f})
11433 When set to @code{#t}, do not prompt the user for a login name. This
11434 can be used with @var{login-program} field to use non-standard login
11437 @item @code{no-newline?} (default: @code{#f})
11438 When set to @code{#t}, do not print a newline before printing the
11439 @file{/etc/issue} file.
11441 @c Is this dangerous only when used with login-program, or always?
11442 @item @code{login-options} (default: @code{#f})
11443 This option accepts a string containing options that are passed to the
11444 login program. When used with the @var{login-program}, be aware that a
11445 malicious user could try to enter a login name containing embedded
11446 options that could be parsed by the login program.
11448 @item @code{login-pause} (default: @code{#f})
11449 When set to @code{#t}, wait for any key before showing the login prompt.
11450 This can be used in conjunction with @var{auto-login} to save memory by
11451 lazily spawning shells.
11453 @item @code{chroot} (default: @code{#f})
11454 Change root to the specified directory. This option accepts a directory
11457 @item @code{hangup?} (default: @code{#f})
11458 Use the Linux system call @code{vhangup} to do a virtual hangup of the
11459 specified terminal.
11461 @item @code{keep-baud?} (default: @code{#f})
11462 When set to @code{#t}, try to keep the existing baud rate. The baud
11463 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
11466 @item @code{timeout} (default: @code{#f})
11467 When set to an integer value, terminate if no user name could be read
11468 within @var{timeout} seconds.
11470 @item @code{detect-case?} (default: @code{#f})
11471 When set to @code{#t}, turn on support for detecting an uppercase-only
11472 terminal. This setting will detect a login name containing only
11473 uppercase letters as indicating an uppercase-only terminal and turn on
11474 some upper-to-lower case conversions. Note that this will not support
11475 Unicode characters.
11477 @item @code{wait-cr?} (default: @code{#f})
11478 When set to @code{#t}, wait for the user or modem to send a
11479 carriage-return or linefeed character before displaying
11480 @file{/etc/issue} or login prompt. This is typically used with the
11481 @var{init-string} option.
11483 @item @code{no-hints?} (default: @code{#f})
11484 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
11487 @item @code{no-hostname?} (default: @code{#f})
11488 By default, the hostname is printed. When this option is set to
11489 @code{#t}, no hostname will be shown at all.
11491 @item @code{long-hostname?} (default: @code{#f})
11492 By default, the hostname is only printed until the first dot. When this
11493 option is set to @code{#t}, the fully qualified hostname by
11494 @code{gethostname} or @code{getaddrinfo} is shown.
11496 @item @code{erase-characters} (default: @code{#f})
11497 This option accepts a string of additional characters that should be
11498 interpreted as backspace when the user types their login name.
11500 @item @code{kill-characters} (default: @code{#f})
11501 This option accepts a string that should be interpreted to mean "ignore
11502 all previous characters" (also called a "kill" character) when the types
11505 @item @code{chdir} (default: @code{#f})
11506 This option accepts, as a string, a directory path that will be changed
11509 @item @code{delay} (default: @code{#f})
11510 This options accepts, as an integer, the number of seconds to sleep
11511 before opening the tty and displaying the login prompt.
11513 @item @code{nice} (default: @code{#f})
11514 This option accepts, as an integer, the nice value with which to run the
11515 @command{login} program.
11517 @item @code{extra-options} (default: @code{'()})
11518 This option provides an "escape hatch" for the user to provide arbitrary
11519 command-line arguments to @command{agetty} as a list of strings.
11524 @deffn {Scheme Procedure} kmscon-service-type @var{config}
11525 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
11526 according to @var{config}, a @code{<kmscon-configuration>} object, which
11527 specifies the tty to run, among other things.
11530 @deftp {Data Type} kmscon-configuration
11531 This is the data type representing the configuration of Kmscon, which
11532 implements virtual console log-in.
11536 @item @code{virtual-terminal}
11537 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
11539 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
11540 A gexp denoting the name of the log-in program. The default log-in program is
11541 @command{login} from the Shadow tool suite.
11543 @item @code{login-arguments} (default: @code{'("-p")})
11544 A list of arguments to pass to @command{login}.
11546 @item @code{auto-login} (default: @code{#f})
11547 When passed a login name, as a string, the specified user will be logged
11548 in automatically without prompting for their login name or password.
11550 @item @code{hardware-acceleration?} (default: #f)
11551 Whether to use hardware acceleration.
11553 @item @code{kmscon} (default: @var{kmscon})
11554 The Kmscon package to use.
11559 @cindex name service cache daemon
11561 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
11562 [#:name-services '()]
11563 Return a service that runs the libc name service cache daemon (nscd) with the
11564 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
11565 Service Switch}, for an example.
11567 For convenience, the Shepherd service for nscd provides the following actions:
11571 @cindex cache invalidation, nscd
11572 @cindex nscd, cache invalidation
11573 This invalidate the given cache. For instance, running:
11576 herd invalidate nscd hosts
11580 invalidates the host name lookup cache of nscd.
11583 Running @command{herd statistics nscd} displays information about nscd usage
11589 @defvr {Scheme Variable} %nscd-default-configuration
11590 This is the default @code{<nscd-configuration>} value (see below) used
11591 by @code{nscd-service}. It uses the caches defined by
11592 @var{%nscd-default-caches}; see below.
11595 @deftp {Data Type} nscd-configuration
11596 This is the data type representing the name service cache daemon (nscd)
11601 @item @code{name-services} (default: @code{'()})
11602 List of packages denoting @dfn{name services} that must be visible to
11603 the nscd---e.g., @code{(list @var{nss-mdns})}.
11605 @item @code{glibc} (default: @var{glibc})
11606 Package object denoting the GNU C Library providing the @command{nscd}
11609 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
11610 Name of the nscd log file. This is where debugging output goes when
11611 @code{debug-level} is strictly positive.
11613 @item @code{debug-level} (default: @code{0})
11614 Integer denoting the debugging levels. Higher numbers mean that more
11615 debugging output is logged.
11617 @item @code{caches} (default: @var{%nscd-default-caches})
11618 List of @code{<nscd-cache>} objects denoting things to be cached; see
11624 @deftp {Data Type} nscd-cache
11625 Data type representing a cache database of nscd and its parameters.
11629 @item @code{database}
11630 This is a symbol representing the name of the database to be cached.
11631 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
11632 @code{services}, which designate the corresponding NSS database
11633 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
11635 @item @code{positive-time-to-live}
11636 @itemx @code{negative-time-to-live} (default: @code{20})
11637 A number representing the number of seconds during which a positive or
11638 negative lookup result remains in cache.
11640 @item @code{check-files?} (default: @code{#t})
11641 Whether to check for updates of the files corresponding to
11644 For instance, when @var{database} is @code{hosts}, setting this flag
11645 instructs nscd to check for updates in @file{/etc/hosts} and to take
11648 @item @code{persistent?} (default: @code{#t})
11649 Whether the cache should be stored persistently on disk.
11651 @item @code{shared?} (default: @code{#t})
11652 Whether the cache should be shared among users.
11654 @item @code{max-database-size} (default: 32@tie{}MiB)
11655 Maximum size in bytes of the database cache.
11657 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
11658 @c settings, so leave them out.
11663 @defvr {Scheme Variable} %nscd-default-caches
11664 List of @code{<nscd-cache>} objects used by default by
11665 @code{nscd-configuration} (see above).
11667 It enables persistent and aggressive caching of service and host name
11668 lookups. The latter provides better host name lookup performance,
11669 resilience in the face of unreliable name servers, and also better
11670 privacy---often the result of host name lookups is in local cache, so
11671 external name servers do not even need to be queried.
11674 @anchor{syslog-configuration-type}
11677 @deftp {Data Type} syslog-configuration
11678 This data type represents the configuration of the syslog daemon.
11681 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
11682 The syslog daemon to use.
11684 @item @code{config-file} (default: @code{%default-syslog.conf})
11685 The syslog configuration file to use.
11690 @anchor{syslog-service}
11692 @deffn {Scheme Procedure} syslog-service @var{config}
11693 Return a service that runs a syslog daemon according to @var{config}.
11695 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
11696 information on the configuration file syntax.
11699 @defvr {Scheme Variable} guix-service-type
11700 This is the type of the service that runs the build daemon,
11701 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
11702 @code{guix-configuration} record as described below.
11705 @anchor{guix-configuration-type}
11706 @deftp {Data Type} guix-configuration
11707 This data type represents the configuration of the Guix build daemon.
11708 @xref{Invoking guix-daemon}, for more information.
11711 @item @code{guix} (default: @var{guix})
11712 The Guix package to use.
11714 @item @code{build-group} (default: @code{"guixbuild"})
11715 Name of the group for build user accounts.
11717 @item @code{build-accounts} (default: @code{10})
11718 Number of build user accounts to create.
11720 @item @code{authorize-key?} (default: @code{#t})
11721 @cindex substitutes, authorization thereof
11722 Whether to authorize the substitute keys listed in
11723 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
11724 (@pxref{Substitutes}).
11726 @vindex %default-authorized-guix-keys
11727 @item @code{authorized-keys} (default: @var{%default-authorized-guix-keys})
11728 The list of authorized key files for archive imports, as a list of
11729 string-valued gexps (@pxref{Invoking guix archive}). By default, it
11730 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
11732 @item @code{use-substitutes?} (default: @code{#t})
11733 Whether to use substitutes.
11735 @item @code{substitute-urls} (default: @var{%default-substitute-urls})
11736 The list of URLs where to look for substitutes by default.
11738 @item @code{max-silent-time} (default: @code{0})
11739 @itemx @code{timeout} (default: @code{0})
11740 The number of seconds of silence and the number of seconds of activity,
11741 respectively, after which a build process times out. A value of zero
11742 disables the timeout.
11744 @item @code{log-compression} (default: @code{'bzip2})
11745 The type of compression used for build logs---one of @code{gzip},
11746 @code{bzip2}, or @code{none}.
11748 @item @code{extra-options} (default: @code{'()})
11749 List of extra command-line options for @command{guix-daemon}.
11751 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
11752 File where @command{guix-daemon}'s standard output and standard error
11755 @item @code{http-proxy} (default: @code{#f})
11756 The HTTP proxy used for downloading fixed-output derivations and
11759 @item @code{tmpdir} (default: @code{#f})
11760 A directory path where the @command{guix-daemon} will perform builds.
11765 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
11766 Run @var{udev}, which populates the @file{/dev} directory dynamically.
11767 udev rules can be provided as a list of files through the @var{rules}
11768 variable. The procedures @var{udev-rule} and @var{file->udev-rule} from
11769 @code{(gnu services base)} simplify the creation of such rule files.
11772 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
11773 Return a udev-rule file named @var{file-name} containing the rules
11774 defined by the @var{contents} literal.
11776 In the following example, a rule for a USB device is defined to be
11777 stored in the file @file{90-usb-thing.rules}. The rule runs a script
11778 upon detecting a USB device with a given product identifier.
11781 (define %example-udev-rule
11783 "90-usb-thing.rules"
11784 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
11785 "ATTR@{product@}==\"Example\", "
11786 "RUN+=\"/path/to/script\"")))
11789 The @command{herd rules udev} command, as root, returns the name of the
11790 directory containing all the active udev rules.
11793 Here we show how the default @var{udev-service} can be extended with it.
11799 (modify-services %desktop-services
11800 (udev-service-type config =>
11801 (udev-configuration (inherit config)
11802 (rules (append (udev-configuration-rules config)
11803 (list %example-udev-rule))))))))
11806 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
11807 Return a udev file named @var{file-name} containing the rules defined
11808 within @var{file}, a file-like object.
11810 The following example showcases how we can use an existing rule file.
11813 (use-modules (guix download) ;for url-fetch
11814 (guix packages) ;for origin
11817 (define %android-udev-rules
11819 "51-android-udev.rules"
11820 (let ((version "20170910"))
11823 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
11824 "android-udev-rules/" version "/51-android.rules"))
11826 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
11830 Additionally, Guix package definitions can be included in @var{rules} in
11831 order to extend the udev rules with the definitions found under their
11832 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
11833 @var{file->udev-rule} example, we could have used the
11834 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
11835 packages android)} module.
11837 The following example shows how to use the @var{android-udev-rules}
11838 package so that the Android tool @command{adb} can detect devices
11839 without root privileges. It also details how to create the
11840 @code{adbusers} group, which is required for the proper functioning of
11841 the rules defined within the @var{android-udev-rules} package. To
11842 create such a group, we must define it both as part of the
11843 @var{supplementary-groups} of our @var{user-account} declaration, as
11844 well as in the @var{groups} field of the @var{operating-system} record.
11847 (use-modules (gnu packages android) ;for android-udev-rules
11848 (gnu system shadow) ;for user-group
11853 (users (cons (user-acount
11855 (supplementary-groups
11856 '("adbusers" ;for adb
11857 "wheel" "netdev" "audio" "video"))
11860 (groups (cons (user-group (system? #t) (name "adbusers"))
11866 (modify-services %desktop-services
11869 (udev-configuration (inherit config)
11870 (rules (cons android-udev-rules
11871 (udev-configuration-rules config))))))))
11874 @defvr {Scheme Variable} urandom-seed-service-type
11875 Save some entropy in @var{%random-seed-file} to seed @file{/dev/urandom}
11876 when rebooting. It also tries to seed @file{/dev/urandom} from
11877 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
11881 @defvr {Scheme Variable} %random-seed-file
11882 This is the name of the file where some random bytes are saved by
11883 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
11884 It defaults to @file{/var/lib/random-seed}.
11889 @deffn {Scheme Procedure} console-keymap-service @var{files} ...
11890 @cindex keyboard layout
11891 Return a service to load console keymaps from @var{files} using
11892 @command{loadkeys} command. Most likely, you want to load some default
11893 keymap, which can be done like this:
11896 (console-keymap-service "dvorak")
11899 Or, for example, for a Swedish keyboard, you may need to combine
11900 the following keymaps:
11902 (console-keymap-service "se-lat6" "se-fi-lat6")
11905 Also you can specify a full file name (or file names) of your keymap(s).
11906 See @code{man loadkeys} for details.
11912 @defvr {Scheme Variable} gpm-service-type
11913 This is the type of the service that runs GPM, the @dfn{general-purpose
11914 mouse daemon}, which provides mouse support to the Linux console. GPM
11915 allows users to use the mouse in the console, notably to select, copy,
11918 The value for services of this type must be a @code{gpm-configuration}
11919 (see below). This service is not part of @var{%base-services}.
11922 @deftp {Data Type} gpm-configuration
11923 Data type representing the configuration of GPM.
11926 @item @code{options} (default: @code{%default-gpm-options})
11927 Command-line options passed to @command{gpm}. The default set of
11928 options instruct @command{gpm} to listen to mouse events on
11929 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
11932 @item @code{gpm} (default: @code{gpm})
11933 The GPM package to use.
11938 @anchor{guix-publish-service-type}
11939 @deffn {Scheme Variable} guix-publish-service-type
11940 This is the service type for @command{guix publish} (@pxref{Invoking
11941 guix publish}). Its value must be a @code{guix-configuration}
11942 object, as described below.
11944 This assumes that @file{/etc/guix} already contains a signing key pair as
11945 created by @command{guix archive --generate-key} (@pxref{Invoking guix
11946 archive}). If that is not the case, the service will fail to start.
11949 @deftp {Data Type} guix-publish-configuration
11950 Data type representing the configuration of the @code{guix publish}
11954 @item @code{guix} (default: @code{guix})
11955 The Guix package to use.
11957 @item @code{port} (default: @code{80})
11958 The TCP port to listen for connections.
11960 @item @code{host} (default: @code{"localhost"})
11961 The host (and thus, network interface) to listen to. Use
11962 @code{"0.0.0.0"} to listen on all the network interfaces.
11964 @item @code{compression-level} (default: @code{3})
11965 The gzip compression level at which substitutes are compressed. Use
11966 @code{0} to disable compression altogether, and @code{9} to get the best
11967 compression ratio at the expense of increased CPU usage.
11969 @item @code{nar-path} (default: @code{"nar"})
11970 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
11971 publish, @code{--nar-path}}, for details.
11973 @item @code{cache} (default: @code{#f})
11974 When it is @code{#f}, disable caching and instead generate archives on
11975 demand. Otherwise, this should be the name of a directory---e.g.,
11976 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
11977 archives and meta-data ready to be sent. @xref{Invoking guix publish,
11978 @option{--cache}}, for more information on the tradeoffs involved.
11980 @item @code{workers} (default: @code{#f})
11981 When it is an integer, this is the number of worker threads used for
11982 caching; when @code{#f}, the number of processors is used.
11983 @xref{Invoking guix publish, @option{--workers}}, for more information.
11985 @item @code{ttl} (default: @code{#f})
11986 When it is an integer, this denotes the @dfn{time-to-live} in seconds
11987 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
11988 for more information.
11992 @anchor{rngd-service}
11993 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
11994 [#:device "/dev/hwrng"]
11995 Return a service that runs the @command{rngd} program from @var{rng-tools}
11996 to add @var{device} to the kernel's entropy pool. The service will fail if
11997 @var{device} does not exist.
12000 @anchor{pam-limits-service}
12001 @cindex session limits
12006 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
12008 Return a service that installs a configuration file for the
12009 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
12010 @code{pam_limits} module}. The procedure optionally takes a list of
12011 @code{pam-limits-entry} values, which can be used to specify
12012 @code{ulimit} limits and nice priority limits to user sessions.
12014 The following limits definition sets two hard and soft limits for all
12015 login sessions of users in the @code{realtime} group:
12018 (pam-limits-service
12020 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
12021 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
12024 The first entry increases the maximum realtime priority for
12025 non-privileged processes; the second entry lifts any restriction of the
12026 maximum address space that can be locked in memory. These settings are
12027 commonly used for real-time audio systems.
12030 @node Scheduled Job Execution
12031 @subsection Scheduled Job Execution
12035 @cindex scheduling jobs
12036 The @code{(gnu services mcron)} module provides an interface to
12037 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
12038 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
12039 Unix @command{cron} daemon; the main difference is that it is
12040 implemented in Guile Scheme, which provides a lot of flexibility when
12041 specifying the scheduling of jobs and their actions.
12043 The example below defines an operating system that runs the
12044 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
12045 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
12046 well as the @command{mkid} command on behalf of an unprivileged user
12047 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
12048 gexps to introduce job definitions that are passed to mcron
12049 (@pxref{G-Expressions}).
12052 (use-modules (guix) (gnu) (gnu services mcron))
12053 (use-package-modules base idutils)
12055 (define updatedb-job
12056 ;; Run 'updatedb' at 3AM every day. Here we write the
12057 ;; job's action as a Scheme procedure.
12058 #~(job '(next-hour '(3))
12060 (execl (string-append #$findutils "/bin/updatedb")
12062 "--prunepaths=/tmp /var/tmp /gnu/store"))))
12064 (define garbage-collector-job
12065 ;; Collect garbage 5 minutes after midnight every day.
12066 ;; The job's action is a shell command.
12067 #~(job "5 0 * * *" ;Vixie cron syntax
12070 (define idutils-job
12071 ;; Update the index database as user "charlie" at 12:15PM
12072 ;; and 19:15PM. This runs from the user's home directory.
12073 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
12074 (string-append #$idutils "/bin/mkid src")
12079 (services (cons (service mcron-service-type
12080 (mcron-configuration
12081 (jobs (list garbage-collector-job
12087 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
12088 for more information on mcron job specifications. Below is the
12089 reference of the mcron service.
12091 On a running system, you can use the @code{schedule} action of the service to
12092 visualize the mcron jobs that will be executed next:
12095 # herd schedule mcron
12099 The example above lists the next five tasks that will be executed, but you can
12100 also specify the number of tasks to display:
12103 # herd schedule mcron 10
12106 @defvr {Scheme Variable} mcron-service-type
12107 This is the type of the @code{mcron} service, whose value is an
12108 @code{mcron-configuration} object.
12110 This service type can be the target of a service extension that provides
12111 it additional job specifications (@pxref{Service Composition}). In
12112 other words, it is possible to define services that provide additional
12116 @deftp {Data Type} mcron-configuration
12117 Data type representing the configuration of mcron.
12120 @item @code{mcron} (default: @var{mcron})
12121 The mcron package to use.
12124 This is a list of gexps (@pxref{G-Expressions}), where each gexp
12125 corresponds to an mcron job specification (@pxref{Syntax, mcron job
12126 specifications,, mcron, GNU@tie{}mcron}).
12132 @subsection Log Rotation
12135 @cindex log rotation
12137 Log files such as those found in @file{/var/log} tend to grow endlessly,
12138 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
12139 their contents in separate files, possibly compressed. The @code{(gnu
12140 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
12141 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
12143 The example below defines an operating system that provides log rotation
12144 with the default settings, for commonly encountered log files.
12147 (use-modules (guix) (gnu))
12148 (use-service-modules admin mcron)
12149 (use-package-modules base idutils)
12153 (services (cons (service rottlog-service-type)
12157 @defvr {Scheme Variable} rottlog-service-type
12158 This is the type of the Rottlog service, whose value is a
12159 @code{rottlog-configuration} object.
12161 Other services can extend this one with new @code{log-rotation} objects
12162 (see below), thereby augmenting the set of files to be rotated.
12164 This service type can define mcron jobs (@pxref{Scheduled Job
12165 Execution}) to run the rottlog service.
12168 @deftp {Data Type} rottlog-configuration
12169 Data type representing the configuration of rottlog.
12172 @item @code{rottlog} (default: @code{rottlog})
12173 The Rottlog package to use.
12175 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
12176 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
12177 rottlog, GNU Rot[t]log Manual}).
12179 @item @code{rotations} (default: @code{%default-rotations})
12180 A list of @code{log-rotation} objects as defined below.
12183 This is a list of gexps where each gexp corresponds to an mcron job
12184 specification (@pxref{Scheduled Job Execution}).
12188 @deftp {Data Type} log-rotation
12189 Data type representing the rotation of a group of log files.
12191 Taking an example from the Rottlog manual (@pxref{Period Related File
12192 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
12198 (files '("/var/log/apache/*"))
12199 (options '("storedir apache-archives"
12205 The list of fields is as follows:
12208 @item @code{frequency} (default: @code{'weekly})
12209 The log rotation frequency, a symbol.
12212 The list of files or file glob patterns to rotate.
12214 @item @code{options} (default: @code{'()})
12215 The list of rottlog options for this rotation (@pxref{Configuration
12216 parameters,,, rottlog, GNU Rot[t]lg Manual}).
12218 @item @code{post-rotate} (default: @code{#f})
12219 Either @code{#f} or a gexp to execute once the rotation has completed.
12223 @defvr {Scheme Variable} %default-rotations
12224 Specifies weekly rotation of @var{%rotated-files} and
12225 a couple of other files.
12228 @defvr {Scheme Variable} %rotated-files
12229 The list of syslog-controlled files to be rotated. By default it is:
12230 @code{'("/var/log/messages" "/var/log/secure")}.
12233 @node Networking Services
12234 @subsection Networking Services
12236 The @code{(gnu services networking)} module provides services to configure
12237 the network interface.
12239 @cindex DHCP, networking service
12240 @defvr {Scheme Variable} dhcp-client-service-type
12241 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
12242 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
12243 is the DHCP client package to use, @code{isc-dhcp} by default.
12246 @deffn {Scheme Procedure} dhcpd-service-type
12247 This type defines a service that runs a DHCP daemon. To create a
12248 service of this type, you must supply a @code{<dhcpd-configuration>}.
12252 (service dhcpd-service-type
12253 (dhcpd-configuration
12254 (config-file (local-file "my-dhcpd.conf"))
12255 (interfaces '("enp0s25"))))
12259 @deftp {Data Type} dhcpd-configuration
12261 @item @code{package} (default: @code{isc-dhcp})
12262 The package that provides the DHCP daemon. This package is expected to
12263 provide the daemon at @file{sbin/dhcpd} relative to its output
12264 directory. The default package is the
12265 @uref{http://www.isc.org/products/DHCP, ISC's DHCP server}.
12266 @item @code{config-file} (default: @code{#f})
12267 The configuration file to use. This is required. It will be passed to
12268 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
12269 object (@pxref{G-Expressions, file-like objects}). See @code{man
12270 dhcpd.conf} for details on the configuration file syntax.
12271 @item @code{version} (default: @code{"4"})
12272 The DHCP version to use. The ISC DHCP server supports the values ``4'',
12273 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
12274 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
12276 @item @code{run-directory} (default: @code{"/run/dhcpd"})
12277 The run directory to use. At service activation time, this directory
12278 will be created if it does not exist.
12279 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
12280 The PID file to use. This corresponds to the @code{-pf} option of
12281 @code{dhcpd}. See @code{man dhcpd} for details.
12282 @item @code{interfaces} (default: @code{'()})
12283 The names of the network interfaces on which dhcpd should listen for
12284 broadcasts. If this list is not empty, then its elements (which must be
12285 strings) will be appended to the @code{dhcpd} invocation when starting
12286 the daemon. It may not be necessary to explicitly specify any
12287 interfaces here; see @code{man dhcpd} for details.
12291 @defvr {Scheme Variable} static-networking-service-type
12292 This is the type for statically-configured network interfaces.
12293 @c TODO Document <static-networking> data structures.
12296 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
12297 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
12298 [#:requirement @code{'(udev)}]
12299 Return a service that starts @var{interface} with address @var{ip}. If
12300 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
12301 it must be a string specifying the default network gateway. @var{requirement}
12302 can be used to declare a dependency on another service before configuring the
12305 This procedure can be called several times, one for each network
12306 interface of interest. Behind the scenes what it does is extend
12307 @code{static-networking-service-type} with additional network interfaces
12313 (static-networking-service "eno1" "192.168.1.82"
12314 #:gateway "192.168.1.2"
12315 #:name-servers '("192.168.1.2"))
12322 @cindex network management
12323 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
12324 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
12325 management daemon that aims to simplify wired and wireless networking.
12327 This service adds the @var{wicd} package to the global profile, providing
12328 several commands to interact with the daemon and configure networking:
12329 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
12330 and @command{wicd-curses} user interfaces.
12333 @cindex ModemManager
12335 @defvr {Scheme Variable} modem-manager-service-type
12336 This is the service type for the
12337 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
12338 service. The value for this service type is a
12339 @code{modem-manager-configuration} record.
12341 This service is part of @code{%desktop-services} (@pxref{Desktop
12345 @deftp {Data Type} modem-manager-configuration
12346 Data type representing the configuration of ModemManager.
12349 @item @code{modem-manager} (default: @code{modem-manager})
12350 The ModemManager package to use.
12355 @cindex NetworkManager
12357 @defvr {Scheme Variable} network-manager-service-type
12358 This is the service type for the
12359 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
12360 service. The value for this service type is a
12361 @code{network-manager-configuration} record.
12363 This service is part of @code{%desktop-services} (@pxref{Desktop
12367 @deftp {Data Type} network-manager-configuration
12368 Data type representing the configuration of NetworkManager.
12371 @item @code{network-manager} (default: @code{network-manager})
12372 The NetworkManager package to use.
12374 @item @code{dns} (default: @code{"default"})
12375 Processing mode for DNS, which affects how NetworkManager uses the
12376 @code{resolv.conf} configuration file.
12380 NetworkManager will update @code{resolv.conf} to reflect the nameservers
12381 provided by currently active connections.
12384 NetworkManager will run @code{dnsmasq} as a local caching nameserver,
12385 using a "split DNS" configuration if you are connected to a VPN, and
12386 then update @code{resolv.conf} to point to the local nameserver.
12389 NetworkManager will not modify @code{resolv.conf}.
12392 @item @code{vpn-plugins} (default: @code{'()})
12393 This is the list of available plugins for virtual private networks
12394 (VPNs). An example of this is the @code{network-manager-openvpn}
12395 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
12401 @deffn {Scheme Variable} connman-service-type
12402 This is the service type to run @url{https://01.org/connman,Connman},
12403 a network connection manager.
12405 Its value must be an
12406 @code{connman-configuration} record as in this example:
12409 (service connman-service-type
12410 (connman-configuration
12411 (disable-vpn? #t)))
12414 See below for details about @code{connman-configuration}.
12417 @deftp {Data Type} connman-configuration
12418 Data Type representing the configuration of connman.
12421 @item @code{connman} (default: @var{connman})
12422 The connman package to use.
12424 @item @code{disable-vpn?} (default: @code{#f})
12425 When true, disable connman's vpn plugin.
12429 @cindex WPA Supplicant
12430 @defvr {Scheme Variable} wpa-supplicant-service-type
12431 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
12432 supplicant}, an authentication daemon required to authenticate against
12433 encrypted WiFi or ethernet networks.
12436 @deftp {Data Type} wpa-supplicant-configuration
12437 Data type representing the configuration of WPA Supplicant.
12439 It takes the following parameters:
12442 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
12443 The WPA Supplicant package to use.
12445 @item @code{dbus?} (default: @code{#t})
12446 Whether to listen for requests on D-Bus.
12448 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
12449 Where to store the PID file.
12451 @item @code{interface} (default: @code{#f})
12452 If this is set, it must specify the name of a network interface that
12453 WPA supplicant will control.
12455 @item @code{config-file} (default: @code{#f})
12456 Optional configuration file to use.
12458 @item @code{extra-options} (default: @code{'()})
12459 List of additional command-line arguments to pass to the daemon.
12464 @defvr {Scheme Variable} iptables-service-type
12465 This is the service type to set up an iptables configuration. iptables is a
12466 packet filtering framework supported by the Linux kernel. This service
12467 supports configuring iptables for both IPv4 and IPv6. A simple example
12468 configuration rejecting all incoming connections except those to the ssh port
12472 (service iptables-service-type
12473 (iptables-configuration
12474 (ipv4-rules (plain-file "iptables.rules" "*filter
12478 -A INPUT -p tcp --dport 22 -j ACCEPT
12479 -A INPUT -j REJECT --reject-with icmp-port-unreachable
12482 (ipv6-rules (plain-file "ip6tables.rules" "*filter
12486 -A INPUT -p tcp --dport 22 -j ACCEPT
12487 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
12493 @deftp {Data Type} iptables-configuration
12494 The data type representing the configuration of iptables.
12497 @item @code{iptables} (default: @code{iptables})
12498 The iptables package that provides @code{iptables-restore} and
12499 @code{ip6tables-restore}.
12500 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
12501 The iptables rules to use. It will be passed to @code{iptables-restore}.
12502 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
12504 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
12505 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
12506 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
12511 @cindex NTP (Network Time Protocol), service
12512 @cindex real time clock
12513 @defvr {Scheme Variable} ntp-service-type
12514 This is the type of the service running the @uref{http://www.ntp.org,
12515 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
12516 system clock synchronized with that of the specified NTP servers.
12518 The value of this service is an @code{ntpd-configuration} object, as described
12522 @deftp {Data Type} ntp-configuration
12523 This is the data type for the NTP service configuration.
12526 @item @code{servers} (default: @code{%ntp-servers})
12527 This is the list of servers (host names) with which @command{ntpd} will be
12530 @item @code{allow-large-adjustment?} (default: @code{#f})
12531 This determines whether @command{ntpd} is allowed to make an initial
12532 adjustment of more than 1,000 seconds.
12534 @item @code{ntp} (default: @code{ntp})
12535 The NTP package to use.
12539 @defvr {Scheme Variable} %ntp-servers
12540 List of host names used as the default NTP servers. These are servers of the
12541 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
12545 @deffn {Scheme Procedure} openntpd-service-type
12546 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
12547 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
12548 clock synchronized with that of the given servers.
12552 openntpd-service-type
12553 (openntpd-configuration
12554 (listen-on '("127.0.0.1" "::1"))
12555 (sensor '("udcf0 correction 70000"))
12556 (constraint-from '("www.gnu.org"))
12557 (constraints-from '("https://www.google.com/"))
12558 (allow-large-adjustment? #t)))
12563 @deftp {Data Type} openntpd-configuration
12565 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
12566 The openntpd executable to use.
12567 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
12568 A list of local IP addresses or hostnames the ntpd daemon should listen on.
12569 @item @code{query-from} (default: @code{'()})
12570 A list of local IP address the ntpd daemon should use for outgoing queries.
12571 @item @code{sensor} (default: @code{'()})
12572 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
12573 will listen to each sensor that acutally exists and ignore non-existant ones.
12574 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
12576 @item @code{server} (default: @var{%ntp-servers})
12577 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
12578 @item @code{servers} (default: @code{'()})
12579 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
12580 @item @code{constraint-from} (default: @code{'()})
12581 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
12582 This time information is not used for precision but acts as an authenticated
12583 constraint, thereby reducing the impact of unauthenticated NTP
12584 man-in-the-middle attacks.
12585 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
12587 @item @code{constraints-from} (default: @code{'()})
12588 As with constraint from, specify a list of URLs, IP addresses or hostnames of
12589 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
12590 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
12591 @item @code{allow-large-adjustment?} (default: @code{#f})
12592 Determines if @code{ntpd} is allowed to make an initial adjustment of more
12598 @deffn {Scheme variable} inetd-service-type
12599 This service runs the @command{inetd} (@pxref{inetd invocation,,,
12600 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
12601 connections on internet sockets, and lazily starts the specified server
12602 program when a connection is made on one of these sockets.
12604 The value of this service is an @code{inetd-configuration} object. The
12605 following example configures the @command{inetd} daemon to provide the
12606 built-in @command{echo} service, as well as an smtp service which
12607 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
12608 gateway @code{hostname}:
12613 (inetd-configuration
12617 (socket-type 'stream)
12624 (socket-type 'stream)
12628 (program (file-append openssh "/bin/ssh"))
12630 '("ssh" "-qT" "-i" "/path/to/ssh_key"
12631 "-W" "smtp-server:25" "user@@hostname")))))
12634 See below for more details about @code{inetd-configuration}.
12637 @deftp {Data Type} inetd-configuration
12638 Data type representing the configuration of @command{inetd}.
12641 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
12642 The @command{inetd} executable to use.
12644 @item @code{entries} (default: @code{'()})
12645 A list of @command{inetd} service entries. Each entry should be created
12646 by the @code{inetd-entry} constructor.
12650 @deftp {Data Type} inetd-entry
12651 Data type representing an entry in the @command{inetd} configuration.
12652 Each entry corresponds to a socket where @command{inetd} will listen for
12656 @item @code{node} (default: @code{#f})
12657 Optional string, a comma-separated list of local addresses
12658 @command{inetd} should use when listening for this service.
12659 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
12660 description of all options.
12662 A string, the name must correspond to an entry in @code{/etc/services}.
12663 @item @code{socket-type}
12664 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
12666 @item @code{protocol}
12667 A string, must correspond to an entry in @code{/etc/protocols}.
12668 @item @code{wait?} (default: @code{#t})
12669 Whether @command{inetd} should wait for the server to exit before
12670 listening to new service requests.
12672 A string containing the user (and, optionally, group) name of the user
12673 as whom the server should run. The group name can be specified in a
12674 suffix, separated by a colon or period, i.e.@: @code{"user"},
12675 @code{"user:group"} or @code{"user.group"}.
12676 @item @code{program} (default: @code{"internal"})
12677 The server program which will serve the requests, or @code{"internal"}
12678 if @command{inetd} should use a built-in service.
12679 @item @code{arguments} (default: @code{'()})
12680 A list strings or file-like objects, which are the server program's
12681 arguments, starting with the zeroth argument, i.e.@: the name of the
12682 program itself. For @command{inetd}'s internal services, this entry
12683 must be @code{'()} or @code{'("internal")}.
12686 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
12687 detailed discussion of each configuration field.
12691 @defvr {Scheme Variable} tor-service-type
12692 This is the type for a service that runs the @uref{https://torproject.org,
12693 Tor} anonymous networking daemon. The service is configured using a
12694 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
12695 @code{tor} unprivileged user, which is a member of the @code{tor} group.
12699 @deftp {Data Type} tor-configuration
12701 @item @code{tor} (default: @code{tor})
12702 The package that provides the Tor daemon. This package is expected to provide
12703 the daemon at @file{bin/tor} relative to its output directory. The default
12704 package is the @uref{https://www.torproject.org, Tor Project's}
12707 @item @code{config-file} (default: @code{(plain-file "empty" "")})
12708 The configuration file to use. It will be appended to a default configuration
12709 file, and the final configuration file will be passed to @code{tor} via its
12710 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
12711 file-like objects}). See @code{man tor} for details on the configuration file
12714 @item @code{hidden-services} (default: @code{'()})
12715 The list of @code{<hidden-service>} records to use. For any hidden service
12716 you include in this list, appropriate configuration to enable the hidden
12717 service will be automatically added to the default configuration file. You
12718 may conveniently create @code{<hidden-service>} records using the
12719 @code{tor-hidden-service} procedure described below.
12721 @item @code{socks-socket-type} (default: @code{'tcp})
12722 The default socket type that Tor should use for its SOCKS socket. This must
12723 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
12724 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
12725 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
12726 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
12729 If you want to customize the SOCKS socket in more detail, leave
12730 @code{socks-socket-type} at its default value of @code{'tcp} and use
12731 @code{config-file} to override the default by providing your own
12732 @code{SocksPort} option.
12736 @cindex hidden service
12737 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
12738 Define a new Tor @dfn{hidden service} called @var{name} and implementing
12739 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
12742 '((22 "127.0.0.1:22")
12743 (80 "127.0.0.1:8080"))
12746 In this example, port 22 of the hidden service is mapped to local port 22, and
12747 port 80 is mapped to local port 8080.
12749 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
12750 the @file{hostname} file contains the @code{.onion} host name for the hidden
12753 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
12754 project's documentation} for more information.
12757 The @code{(gnu services rsync)} module provides the following services:
12759 You might want an rsync daemon if you have files that you want available
12760 so anyone (or just yourself) can download existing files or upload new
12763 @deffn {Scheme Variable} rsync-service-type
12764 This is the type for the @uref{https://rsync.samba.org, rsync} rsync daemon,
12765 @command{rsync-configuration} record as in this example:
12768 (service rsync-service-type)
12771 See below for details about @code{rsync-configuration}.
12774 @deftp {Data Type} rsync-configuration
12775 Data type representing the configuration for @code{rsync-service}.
12778 @item @code{package} (default: @var{rsync})
12779 @code{rsync} package to use.
12781 @item @code{port-number} (default: @code{873})
12782 TCP port on which @command{rsync} listens for incoming connections. If port
12783 is less than @code{1024} @command{rsync} needs to be started as the
12784 @code{root} user and group.
12786 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
12787 Name of the file where @command{rsync} writes its PID.
12789 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
12790 Name of the file where @command{rsync} writes its lock file.
12792 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
12793 Name of the file where @command{rsync} writes its log file.
12795 @item @code{use-chroot?} (default: @var{#t})
12796 Whether to use chroot for @command{rsync} shared directory.
12798 @item @code{share-path} (default: @file{/srv/rsync})
12799 Location of the @command{rsync} shared directory.
12801 @item @code{share-comment} (default: @code{"Rsync share"})
12802 Comment of the @command{rsync} shared directory.
12804 @item @code{read-only?} (default: @var{#f})
12805 Read-write permissions to shared directory.
12807 @item @code{timeout} (default: @code{300})
12808 I/O timeout in seconds.
12810 @item @code{user} (default: @var{"root"})
12811 Owner of the @code{rsync} process.
12813 @item @code{group} (default: @var{"root"})
12814 Group of the @code{rsync} process.
12816 @item @code{uid} (default: @var{"rsyncd"})
12817 User name or user ID that file transfers to and from that module should take
12818 place as when the daemon was run as @code{root}.
12820 @item @code{gid} (default: @var{"rsyncd"})
12821 Group name or group ID that will be used when accessing the module.
12826 Furthermore, @code{(gnu services ssh)} provides the following services.
12830 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
12831 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
12832 [#:allow-empty-passwords? #f] [#:root-login? #f] @
12833 [#:syslog-output? #t] [#:x11-forwarding? #t] @
12834 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
12835 [#:public-key-authentication? #t] [#:initialize? #t]
12836 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
12837 @var{host-key} must designate a file containing the host key, and readable
12840 When @var{daemonic?} is true, @command{lshd} will detach from the
12841 controlling terminal and log its output to syslogd, unless one sets
12842 @var{syslog-output?} to false. Obviously, it also makes lsh-service
12843 depend on existence of syslogd service. When @var{pid-file?} is true,
12844 @command{lshd} writes its PID to the file called @var{pid-file}.
12846 When @var{initialize?} is true, automatically create the seed and host key
12847 upon service activation if they do not exist yet. This may take long and
12848 require interaction.
12850 When @var{initialize?} is false, it is up to the user to initialize the
12851 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
12852 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
12853 basics,,, lsh, LSH Manual}).
12855 When @var{interfaces} is empty, lshd listens for connections on all the
12856 network interfaces; otherwise, @var{interfaces} must be a list of host names
12859 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
12860 passwords, and @var{root-login?} specifies whether to accept log-ins as
12863 The other options should be self-descriptive.
12868 @deffn {Scheme Variable} openssh-service-type
12869 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
12870 shell daemon, @command{sshd}. Its value must be an
12871 @code{openssh-configuration} record as in this example:
12874 (service openssh-service-type
12875 (openssh-configuration
12876 (x11-forwarding? #t)
12877 (permit-root-login 'without-password)
12879 `(("alice" ,(local-file "alice.pub"))
12880 ("bob" ,(local-file "bob.pub"))))))
12883 See below for details about @code{openssh-configuration}.
12885 This service can be extended with extra authorized keys, as in this
12889 (service-extension openssh-service-type
12890 (const `(("charlie"
12891 ,(local-file "charlie.pub")))))
12895 @deftp {Data Type} openssh-configuration
12896 This is the configuration record for OpenSSH's @command{sshd}.
12899 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
12900 Name of the file where @command{sshd} writes its PID.
12902 @item @code{port-number} (default: @code{22})
12903 TCP port on which @command{sshd} listens for incoming connections.
12905 @item @code{permit-root-login} (default: @code{#f})
12906 This field determines whether and when to allow logins as root. If
12907 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
12908 If it's the symbol @code{'without-password}, then root logins are
12909 permitted but not with password-based authentication.
12911 @item @code{allow-empty-passwords?} (default: @code{#f})
12912 When true, users with empty passwords may log in. When false, they may
12915 @item @code{password-authentication?} (default: @code{#t})
12916 When true, users may log in with their password. When false, they have
12917 other authentication methods.
12919 @item @code{public-key-authentication?} (default: @code{#t})
12920 When true, users may log in using public key authentication. When
12921 false, users have to use other authentication method.
12923 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
12924 This is used only by protocol version 2.
12926 @item @code{x11-forwarding?} (default: @code{#f})
12927 When true, forwarding of X11 graphical client connections is
12928 enabled---in other words, @command{ssh} options @option{-X} and
12929 @option{-Y} will work.
12931 @item @code{allow-agent-forwarding?} (default: @code{#t})
12932 Whether to allow agent forwarding.
12934 @item @code{allow-tcp-forwarding?} (default: @code{#t})
12935 Whether to allow TCP forwarding.
12937 @item @code{gateway-ports?} (default: @code{#f})
12938 Whether to allow gateway ports.
12940 @item @code{challenge-response-authentication?} (default: @code{#f})
12941 Specifies whether challenge response authentication is allowed (e.g.@: via
12944 @item @code{use-pam?} (default: @code{#t})
12945 Enables the Pluggable Authentication Module interface. If set to
12946 @code{#t}, this will enable PAM authentication using
12947 @code{challenge-response-authentication?} and
12948 @code{password-authentication?}, in addition to PAM account and session
12949 module processing for all authentication types.
12951 Because PAM challenge response authentication usually serves an
12952 equivalent role to password authentication, you should disable either
12953 @code{challenge-response-authentication?} or
12954 @code{password-authentication?}.
12956 @item @code{print-last-log?} (default: @code{#t})
12957 Specifies whether @command{sshd} should print the date and time of the
12958 last user login when a user logs in interactively.
12960 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
12961 Configures external subsystems (e.g.@: file transfer daemon).
12963 This is a list of two-element lists, each of which containing the
12964 subsystem name and a command (with optional arguments) to execute upon
12967 The command @command{internal-sftp} implements an in-process SFTP
12968 server. Alternately, one can specify the @command{sftp-server} command:
12970 (service openssh-service-type
12971 (openssh-configuration
12973 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
12976 @item @code{accepted-environment} (default: @code{'()})
12977 List of strings describing which environment variables may be exported.
12979 Each string gets on its own line. See the @code{AcceptEnv} option in
12980 @code{man sshd_config}.
12982 This example allows ssh-clients to export the @code{COLORTERM} variable.
12983 It is set by terminal emulators, which support colors. You can use it in
12984 your shell's ressource file to enable colors for the prompt and commands
12985 if this variable is set.
12988 (service openssh-service-type
12989 (openssh-configuration
12990 (accepted-environment '("COLORTERM"))))
12993 @item @code{authorized-keys} (default: @code{'()})
12994 @cindex authorized keys, SSH
12995 @cindex SSH authorized keys
12996 This is the list of authorized keys. Each element of the list is a user
12997 name followed by one or more file-like objects that represent SSH public
13001 (openssh-configuration
13003 `(("rekado" ,(local-file "rekado.pub"))
13004 ("chris" ,(local-file "chris.pub"))
13005 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
13009 registers the specified public keys for user accounts @code{rekado},
13010 @code{chris}, and @code{root}.
13012 Additional authorized keys can be specified @i{via}
13013 @code{service-extension}.
13015 Note that this does @emph{not} interfere with the use of
13016 @file{~/.ssh/authorized_keys}.
13018 @item @code{log-level} (default: @code{'info})
13019 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
13020 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
13021 page for @file{sshd_config} for the full list of level names.
13023 @item @code{extra-content} (default: @code{""})
13024 This field can be used to append arbitrary text to the configuration file. It
13025 is especially useful for elaborate configurations that cannot be expressed
13026 otherwise. This configuration, for example, would generally disable root
13027 logins, but permit them from one specific IP address:
13030 (openssh-configuration
13032 Match Address 192.168.0.1
13033 PermitRootLogin yes"))
13039 @deffn {Scheme Procedure} dropbear-service [@var{config}]
13040 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
13041 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
13044 For example, to specify a Dropbear service listening on port 1234, add
13045 this call to the operating system's @code{services} field:
13048 (dropbear-service (dropbear-configuration
13049 (port-number 1234)))
13053 @deftp {Data Type} dropbear-configuration
13054 This data type represents the configuration of a Dropbear SSH daemon.
13057 @item @code{dropbear} (default: @var{dropbear})
13058 The Dropbear package to use.
13060 @item @code{port-number} (default: 22)
13061 The TCP port where the daemon waits for incoming connections.
13063 @item @code{syslog-output?} (default: @code{#t})
13064 Whether to enable syslog output.
13066 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
13067 File name of the daemon's PID file.
13069 @item @code{root-login?} (default: @code{#f})
13070 Whether to allow @code{root} logins.
13072 @item @code{allow-empty-passwords?} (default: @code{#f})
13073 Whether to allow empty passwords.
13075 @item @code{password-authentication?} (default: @code{#t})
13076 Whether to enable password-based authentication.
13080 @defvr {Scheme Variable} %facebook-host-aliases
13081 This variable contains a string for use in @file{/etc/hosts}
13082 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
13083 line contains a entry that maps a known server name of the Facebook
13084 on-line service---e.g., @code{www.facebook.com}---to the local
13085 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
13087 This variable is typically used in the @code{hosts-file} field of an
13088 @code{operating-system} declaration (@pxref{operating-system Reference,
13089 @file{/etc/hosts}}):
13092 (use-modules (gnu) (guix))
13095 (host-name "mymachine")
13098 ;; Create a /etc/hosts file with aliases for "localhost"
13099 ;; and "mymachine", as well as for Facebook servers.
13100 (plain-file "hosts"
13101 (string-append (local-host-aliases host-name)
13102 %facebook-host-aliases))))
13105 This mechanism can prevent programs running locally, such as Web
13106 browsers, from accessing Facebook.
13109 The @code{(gnu services avahi)} provides the following definition.
13111 @defvr {Scheme Variable} avahi-service-type
13112 This is the service that runs @command{avahi-daemon}, a system-wide
13113 mDNS/DNS-SD responder that allows for service discovery and
13114 ``zero-configuration'' host name lookups (see @uref{http://avahi.org/}).
13115 Its value must be a @code{zero-configuration} record---see below.
13117 This service extends the name service cache daemon (nscd) so that it can
13118 resolve @code{.local} host names using
13119 @uref{http://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
13120 Service Switch}, for information on host name resolution.
13122 Additionally, add the @var{avahi} package to the system profile so that
13123 commands such as @command{avahi-browse} are directly usable.
13126 @deftp {Data Type} avahi-configuration
13127 Data type representation the configuration for Avahi.
13131 @item @code{host-name} (default: @code{#f})
13132 If different from @code{#f}, use that as the host name to
13133 publish for this machine; otherwise, use the machine's actual host name.
13135 @item @code{publish?} (default: @code{#t})
13136 When true, allow host names and services to be published (broadcast) over the
13139 @item @code{publish-workstation?} (default: @code{#t})
13140 When true, @command{avahi-daemon} publishes the machine's host name and IP
13141 address via mDNS on the local network. To view the host names published on
13142 your local network, you can run:
13145 avahi-browse _workstation._tcp
13148 @item @code{wide-area?} (default: @code{#f})
13149 When true, DNS-SD over unicast DNS is enabled.
13151 @item @code{ipv4?} (default: @code{#t})
13152 @itemx @code{ipv6?} (default: @code{#t})
13153 These fields determine whether to use IPv4/IPv6 sockets.
13155 @item @code{domains-to-browse} (default: @code{'()})
13156 This is a list of domains to browse.
13160 @deffn {Scheme Variable} openvswitch-service-type
13161 This is the type of the @uref{http://www.openvswitch.org, Open vSwitch}
13162 service, whose value should be an @code{openvswitch-configuration}
13166 @deftp {Data Type} openvswitch-configuration
13167 Data type representing the configuration of Open vSwitch, a multilayer
13168 virtual switch which is designed to enable massive network automation
13169 through programmatic extension.
13172 @item @code{package} (default: @var{openvswitch})
13173 Package object of the Open vSwitch.
13179 @subsection X Window
13182 @cindex X Window System
13183 @cindex login manager
13184 Support for the X Window graphical display system---specifically
13185 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
13186 there is no @code{xorg-service} procedure. Instead, the X server is
13187 started by the @dfn{login manager}, by default SLiM.
13189 @cindex window manager
13190 To use X11, you must install at least one @dfn{window manager}---for
13191 example the @code{windowmaker} or @code{openbox} packages---preferably
13192 by adding it to the @code{packages} field of your operating system
13193 definition (@pxref{operating-system Reference, system-wide packages}).
13195 @defvr {Scheme Variable} slim-service-type
13196 This is the type for the SLiM graphical login manager for X11.
13198 @cindex session types (X11)
13199 @cindex X11 session types
13200 SLiM looks for @dfn{session types} described by the @file{.desktop} files in
13201 @file{/run/current-system/profile/share/xsessions} and allows users to
13202 choose a session from the log-in screen using @kbd{F1}. Packages such
13203 as @code{xfce}, @code{sawfish}, and @code{ratpoison} provide
13204 @file{.desktop} files; adding them to the system-wide set of packages
13205 automatically makes them available at the log-in screen.
13207 In addition, @file{~/.xsession} files are honored. When available,
13208 @file{~/.xsession} must be an executable that starts a window manager
13209 and/or other X clients.
13212 @deftp {Data Type} slim-configuration
13213 Data type representing the configuration of @code{slim-service-type}.
13216 @item @code{allow-empty-passwords?} (default: @code{#t})
13217 Whether to allow logins with empty passwords.
13219 @item @code{auto-login?} (default: @code{#f})
13220 @itemx @code{default-user} (default: @code{""})
13221 When @code{auto-login?} is false, SLiM presents a log-in screen.
13223 When @code{auto-login?} is true, SLiM logs in directly as
13224 @code{default-user}.
13226 @item @code{theme} (default: @code{%default-slim-theme})
13227 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
13228 The graphical theme to use and its name.
13230 @item @code{auto-login-session} (default: @code{#f})
13231 If true, this must be the name of the executable to start as the default
13232 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
13234 If false, a session described by one of the available @file{.desktop}
13235 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
13239 You must install at least one window manager in the system profile or in
13240 your user profile. Failing to do that, if @code{auto-login-session} is
13241 false, you will be unable to log in.
13244 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
13245 Configuration of the Xorg graphical server.
13247 @item @code{xauth} (default: @code{xauth})
13248 The XAuth package to use.
13250 @item @code{shepherd} (default: @code{shepherd})
13251 The Shepherd package used when invoking @command{halt} and
13254 @item @code{sessreg} (default: @code{sessreg})
13255 The sessreg package used in order to register the session.
13257 @item @code{slim} (default: @code{slim})
13258 The SLiM package to use.
13262 @defvr {Scheme Variable} %default-theme
13263 @defvrx {Scheme Variable} %default-theme-name
13264 The default SLiM theme and its name.
13268 @deftp {Data Type} sddm-configuration
13269 This is the data type representing the sddm service configuration.
13272 @item @code{display-server} (default: "x11")
13273 Select display server to use for the greeter. Valid values are "x11"
13276 @item @code{numlock} (default: "on")
13277 Valid values are "on", "off" or "none".
13279 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
13280 Command to run when halting.
13282 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
13283 Command to run when rebooting.
13285 @item @code{theme} (default "maldives")
13286 Theme to use. Default themes provided by SDDM are "elarun" or "maldives".
13288 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
13289 Directory to look for themes.
13291 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
13292 Directory to look for faces.
13294 @item @code{default-path} (default "/run/current-system/profile/bin")
13295 Default PATH to use.
13297 @item @code{minimum-uid} (default 1000)
13298 Minimum UID to display in SDDM.
13300 @item @code{maximum-uid} (default 2000)
13301 Maximum UID to display in SDDM
13303 @item @code{remember-last-user?} (default #t)
13304 Remember last user.
13306 @item @code{remember-last-session?} (default #t)
13307 Remember last session.
13309 @item @code{hide-users} (default "")
13310 Usernames to hide from SDDM greeter.
13312 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
13313 Users with shells listed will be hidden from the SDDM greeter.
13315 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
13316 Script to run before starting a wayland session.
13318 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
13319 Directory to look for desktop files starting wayland sessions.
13321 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
13322 Configuration of the Xorg graphical server.
13324 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
13327 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
13330 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
13331 Script to run after starting xorg-server.
13333 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
13334 Script to run before stopping xorg-server.
13336 @item @code{xsession-command} (default: @code{xinitrc})
13337 Script to run before starting a X session.
13339 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
13340 Directory to look for desktop files starting X sessions.
13342 @item @code{minimum-vt} (default: 7)
13345 @item @code{auto-login-user} (default "")
13346 User to use for auto-login.
13348 @item @code{auto-login-session} (default "")
13349 Desktop file to use for auto-login.
13351 @item @code{relogin?} (default #f)
13352 Relogin after logout.
13357 @cindex login manager
13359 @deffn {Scheme Procedure} sddm-service config
13360 Return a service that spawns the SDDM graphical login manager for config of
13361 type @code{<sddm-configuration>}.
13364 (sddm-service (sddm-configuration
13365 (auto-login-user "Alice")
13366 (auto-login-session "xfce.desktop")))
13370 @cindex Xorg, configuration
13371 @deftp {Data Type} xorg-configuration
13372 This data type represents the configuration of the Xorg graphical display
13373 server. Note that there is not Xorg service; instead, the X server is started
13374 by a ``display manager'' such as GDM, SDDM, and SLiM. Thus, the configuration
13375 of these display managers aggregates an @code{xorg-configuration} record.
13378 @item @code{modules} (default: @code{%default-xorg-modules})
13379 This is a list of @dfn{module packages} loaded by the Xorg
13380 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
13382 @item @code{fonts} (default: @code{%default-xorg-fonts})
13383 This is a list of font directories to add to the server's @dfn{font path}.
13385 @item @code{drivers} (default: @code{'()})
13386 This must be either the empty list, in which case Xorg chooses a graphics
13387 driver automatically, or a list of driver names that will be tried in this
13388 order---e.g., @code{("modesetting" "vesa")}.
13390 @item @code{resolutions} (default: @code{'()})
13391 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
13392 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
13395 @cindex keyboard layout, for Xorg
13396 @cindex keymap, for Xorg
13397 @item @code{keyboard-layout} (default: @code{#f})
13398 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
13399 English (``qwerty'') for a 105-key PC keyboard.
13401 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
13402 layout in use when Xorg is running.
13404 @item @code{extra-config} (default: @code{'()})
13405 This is a list of strings or objects appended to the configuration file. It
13406 is used to pass extra text to be added verbatim to the configuration file.
13408 @item @code{server} (default: @code{xorg-server})
13409 This is the package providing the Xorg server.
13411 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
13412 This is the list of command-line arguments to pass to the X server. The
13413 default is @code{-nolisten tcp}.
13417 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
13418 Return a @code{startx} script in which the modules, fonts, etc. specified
13419 in @var{config}, are available. The result should be used in place of
13422 Usually the X server is started by a login manager.
13426 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
13427 Add @var{package}, a package for a screen locker or screen saver whose
13428 command is @var{program}, to the set of setuid programs and add a PAM entry
13429 for it. For example:
13432 (screen-locker-service xlockmore "xlock")
13435 makes the good ol' XlockMore usable.
13439 @node Printing Services
13440 @subsection Printing Services
13442 @cindex printer support with CUPS
13443 The @code{(gnu services cups)} module provides a Guix service definition
13444 for the CUPS printing service. To add printer support to a Guix
13445 system, add a @code{cups-service} to the operating system definition:
13447 @deffn {Scheme Variable} cups-service-type
13448 The service type for the CUPS print server. Its value should be a valid
13449 CUPS configuration (see below). To use the default settings, simply
13452 (service cups-service-type)
13456 The CUPS configuration controls the basic things about your CUPS
13457 installation: what interfaces it listens on, what to do if a print job
13458 fails, how much logging to do, and so on. To actually add a printer,
13459 you have to visit the @url{http://localhost:631} URL, or use a tool such
13460 as GNOME's printer configuration services. By default, configuring a
13461 CUPS service will generate a self-signed certificate if needed, for
13462 secure connections to the print server.
13464 Suppose you want to enable the Web interface of CUPS and also add
13465 support for Epson printers @i{via} the @code{escpr} package and for HP
13466 printers @i{via} the @code{hplip-minimal} package. You can do that directly,
13467 like this (you need to use the @code{(gnu packages cups)} module):
13470 (service cups-service-type
13471 (cups-configuration
13472 (web-interface? #t)
13474 (list cups-filters escpr hplip-minimal))))
13477 Note: If you wish to use the Qt5 based GUI which comes with the hplip
13478 package then it is suggested that you install the @code{hplip} package,
13479 either in your OS configuration file or as your user.
13481 The available configuration parameters follow. Each parameter
13482 definition is preceded by its type; for example, @samp{string-list foo}
13483 indicates that the @code{foo} parameter should be specified as a list of
13484 strings. There is also a way to specify the configuration as a string,
13485 if you have an old @code{cupsd.conf} file that you want to port over
13486 from some other system; see the end for more details.
13488 @c The following documentation was initially generated by
13489 @c (generate-documentation) in (gnu services cups). Manually maintained
13490 @c documentation is better, so we shouldn't hesitate to edit below as
13491 @c needed. However if the change you want to make to this documentation
13492 @c can be done in an automated way, it's probably easier to change
13493 @c (generate-documentation) than to make it below and have to deal with
13494 @c the churn as CUPS updates.
13497 Available @code{cups-configuration} fields are:
13499 @deftypevr {@code{cups-configuration} parameter} package cups
13503 @deftypevr {@code{cups-configuration} parameter} package-list extensions
13504 Drivers and other extensions to the CUPS package.
13507 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
13508 Configuration of where to write logs, what directories to use for print
13509 spools, and related privileged configuration parameters.
13511 Available @code{files-configuration} fields are:
13513 @deftypevr {@code{files-configuration} parameter} log-location access-log
13514 Defines the access log filename. Specifying a blank filename disables
13515 access log generation. The value @code{stderr} causes log entries to be
13516 sent to the standard error file when the scheduler is running in the
13517 foreground, or to the system log daemon when run in the background. The
13518 value @code{syslog} causes log entries to be sent to the system log
13519 daemon. The server name may be included in filenames using the string
13520 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
13522 Defaults to @samp{"/var/log/cups/access_log"}.
13525 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
13526 Where CUPS should cache data.
13528 Defaults to @samp{"/var/cache/cups"}.
13531 @deftypevr {@code{files-configuration} parameter} string config-file-perm
13532 Specifies the permissions for all configuration files that the scheduler
13535 Note that the permissions for the printers.conf file are currently
13536 masked to only allow access from the scheduler user (typically root).
13537 This is done because printer device URIs sometimes contain sensitive
13538 authentication information that should not be generally known on the
13539 system. There is no way to disable this security feature.
13541 Defaults to @samp{"0640"}.
13544 @deftypevr {@code{files-configuration} parameter} log-location error-log
13545 Defines the error log filename. Specifying a blank filename disables
13546 access log generation. The value @code{stderr} causes log entries to be
13547 sent to the standard error file when the scheduler is running in the
13548 foreground, or to the system log daemon when run in the background. The
13549 value @code{syslog} causes log entries to be sent to the system log
13550 daemon. The server name may be included in filenames using the string
13551 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
13553 Defaults to @samp{"/var/log/cups/error_log"}.
13556 @deftypevr {@code{files-configuration} parameter} string fatal-errors
13557 Specifies which errors are fatal, causing the scheduler to exit. The
13562 No errors are fatal.
13565 All of the errors below are fatal.
13568 Browsing initialization errors are fatal, for example failed connections
13569 to the DNS-SD daemon.
13572 Configuration file syntax errors are fatal.
13575 Listen or Port errors are fatal, except for IPv6 failures on the
13576 loopback or @code{any} addresses.
13579 Log file creation or write errors are fatal.
13582 Bad startup file permissions are fatal, for example shared TLS
13583 certificate and key files with world-read permissions.
13586 Defaults to @samp{"all -browse"}.
13589 @deftypevr {@code{files-configuration} parameter} boolean file-device?
13590 Specifies whether the file pseudo-device can be used for new printer
13591 queues. The URI @uref{file:///dev/null} is always allowed.
13593 Defaults to @samp{#f}.
13596 @deftypevr {@code{files-configuration} parameter} string group
13597 Specifies the group name or ID that will be used when executing external
13600 Defaults to @samp{"lp"}.
13603 @deftypevr {@code{files-configuration} parameter} string log-file-perm
13604 Specifies the permissions for all log files that the scheduler writes.
13606 Defaults to @samp{"0644"}.
13609 @deftypevr {@code{files-configuration} parameter} log-location page-log
13610 Defines the page log filename. Specifying a blank filename disables
13611 access log generation. The value @code{stderr} causes log entries to be
13612 sent to the standard error file when the scheduler is running in the
13613 foreground, or to the system log daemon when run in the background. The
13614 value @code{syslog} causes log entries to be sent to the system log
13615 daemon. The server name may be included in filenames using the string
13616 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
13618 Defaults to @samp{"/var/log/cups/page_log"}.
13621 @deftypevr {@code{files-configuration} parameter} string remote-root
13622 Specifies the username that is associated with unauthenticated accesses
13623 by clients claiming to be the root user. The default is @code{remroot}.
13625 Defaults to @samp{"remroot"}.
13628 @deftypevr {@code{files-configuration} parameter} file-name request-root
13629 Specifies the directory that contains print jobs and other HTTP request
13632 Defaults to @samp{"/var/spool/cups"}.
13635 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
13636 Specifies the level of security sandboxing that is applied to print
13637 filters, backends, and other child processes of the scheduler; either
13638 @code{relaxed} or @code{strict}. This directive is currently only
13639 used/supported on macOS.
13641 Defaults to @samp{strict}.
13644 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
13645 Specifies the location of TLS certificates and private keys. CUPS will
13646 look for public and private keys in this directory: a @code{.crt} files
13647 for PEM-encoded certificates and corresponding @code{.key} files for
13648 PEM-encoded private keys.
13650 Defaults to @samp{"/etc/cups/ssl"}.
13653 @deftypevr {@code{files-configuration} parameter} file-name server-root
13654 Specifies the directory containing the server configuration files.
13656 Defaults to @samp{"/etc/cups"}.
13659 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
13660 Specifies whether the scheduler calls fsync(2) after writing
13661 configuration or state files.
13663 Defaults to @samp{#f}.
13666 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
13667 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
13670 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
13671 Specifies the directory where temporary files are stored.
13673 Defaults to @samp{"/var/spool/cups/tmp"}.
13676 @deftypevr {@code{files-configuration} parameter} string user
13677 Specifies the user name or ID that is used when running external
13680 Defaults to @samp{"lp"}.
13684 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
13685 Specifies the logging level for the AccessLog file. The @code{config}
13686 level logs when printers and classes are added, deleted, or modified and
13687 when configuration files are accessed or updated. The @code{actions}
13688 level logs when print jobs are submitted, held, released, modified, or
13689 canceled, and any of the conditions for @code{config}. The @code{all}
13690 level logs all requests.
13692 Defaults to @samp{actions}.
13695 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
13696 Specifies whether to purge job history data automatically when it is no
13697 longer required for quotas.
13699 Defaults to @samp{#f}.
13702 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
13703 Specifies which protocols to use for local printer sharing.
13705 Defaults to @samp{dnssd}.
13708 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
13709 Specifies whether the CUPS web interface is advertised.
13711 Defaults to @samp{#f}.
13714 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
13715 Specifies whether shared printers are advertised.
13717 Defaults to @samp{#f}.
13720 @deftypevr {@code{cups-configuration} parameter} string classification
13721 Specifies the security classification of the server. Any valid banner
13722 name can be used, including "classified", "confidential", "secret",
13723 "topsecret", and "unclassified", or the banner can be omitted to disable
13724 secure printing functions.
13726 Defaults to @samp{""}.
13729 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
13730 Specifies whether users may override the classification (cover page) of
13731 individual print jobs using the @code{job-sheets} option.
13733 Defaults to @samp{#f}.
13736 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
13737 Specifies the default type of authentication to use.
13739 Defaults to @samp{Basic}.
13742 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
13743 Specifies whether encryption will be used for authenticated requests.
13745 Defaults to @samp{Required}.
13748 @deftypevr {@code{cups-configuration} parameter} string default-language
13749 Specifies the default language to use for text and web content.
13751 Defaults to @samp{"en"}.
13754 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
13755 Specifies the default paper size for new print queues. @samp{"Auto"}
13756 uses a locale-specific default, while @samp{"None"} specifies there is
13757 no default paper size. Specific size names are typically
13758 @samp{"Letter"} or @samp{"A4"}.
13760 Defaults to @samp{"Auto"}.
13763 @deftypevr {@code{cups-configuration} parameter} string default-policy
13764 Specifies the default access policy to use.
13766 Defaults to @samp{"default"}.
13769 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
13770 Specifies whether local printers are shared by default.
13772 Defaults to @samp{#t}.
13775 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
13776 Specifies the delay for updating of configuration and state files, in
13777 seconds. A value of 0 causes the update to happen as soon as possible,
13778 typically within a few milliseconds.
13780 Defaults to @samp{30}.
13783 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
13784 Specifies what to do when an error occurs. Possible values are
13785 @code{abort-job}, which will discard the failed print job;
13786 @code{retry-job}, which will retry the job at a later time;
13787 @code{retry-this-job}, which retries the failed job immediately; and
13788 @code{stop-printer}, which stops the printer.
13790 Defaults to @samp{stop-printer}.
13793 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
13794 Specifies the maximum cost of filters that are run concurrently, which
13795 can be used to minimize disk, memory, and CPU resource problems. A
13796 limit of 0 disables filter limiting. An average print to a
13797 non-PostScript printer needs a filter limit of about 200. A PostScript
13798 printer needs about half that (100). Setting the limit below these
13799 thresholds will effectively limit the scheduler to printing a single job
13802 Defaults to @samp{0}.
13805 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
13806 Specifies the scheduling priority of filters that are run to print a
13807 job. The nice value ranges from 0, the highest priority, to 19, the
13810 Defaults to @samp{0}.
13813 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
13814 Specifies whether to do reverse lookups on connecting clients. The
13815 @code{double} setting causes @code{cupsd} to verify that the hostname
13816 resolved from the address matches one of the addresses returned for that
13817 hostname. Double lookups also prevent clients with unregistered
13818 addresses from connecting to your server. Only set this option to
13819 @code{#t} or @code{double} if absolutely required.
13821 Defaults to @samp{#f}.
13824 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
13825 Specifies the number of seconds to wait before killing the filters and
13826 backend associated with a canceled or held job.
13828 Defaults to @samp{30}.
13831 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
13832 Specifies the interval between retries of jobs in seconds. This is
13833 typically used for fax queues but can also be used with normal print
13834 queues whose error policy is @code{retry-job} or
13835 @code{retry-current-job}.
13837 Defaults to @samp{30}.
13840 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
13841 Specifies the number of retries that are done for jobs. This is
13842 typically used for fax queues but can also be used with normal print
13843 queues whose error policy is @code{retry-job} or
13844 @code{retry-current-job}.
13846 Defaults to @samp{5}.
13849 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
13850 Specifies whether to support HTTP keep-alive connections.
13852 Defaults to @samp{#t}.
13855 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
13856 Specifies how long an idle client connection remains open, in seconds.
13858 Defaults to @samp{30}.
13861 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
13862 Specifies the maximum size of print files, IPP requests, and HTML form
13863 data. A limit of 0 disables the limit check.
13865 Defaults to @samp{0}.
13868 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
13869 Listens on the specified interfaces for connections. Valid values are
13870 of the form @var{address}:@var{port}, where @var{address} is either an
13871 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
13872 indicate all addresses. Values can also be file names of local UNIX
13873 domain sockets. The Listen directive is similar to the Port directive
13874 but allows you to restrict access to specific interfaces or networks.
13877 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
13878 Specifies the number of pending connections that will be allowed. This
13879 normally only affects very busy servers that have reached the MaxClients
13880 limit, but can also be triggered by large numbers of simultaneous
13881 connections. When the limit is reached, the operating system will
13882 refuse additional connections until the scheduler can accept the pending
13885 Defaults to @samp{128}.
13888 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
13889 Specifies a set of additional access controls.
13891 Available @code{location-access-controls} fields are:
13893 @deftypevr {@code{location-access-controls} parameter} file-name path
13894 Specifies the URI path to which the access control applies.
13897 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
13898 Access controls for all access to this path, in the same format as the
13899 @code{access-controls} of @code{operation-access-control}.
13901 Defaults to @samp{()}.
13904 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
13905 Access controls for method-specific access to this path.
13907 Defaults to @samp{()}.
13909 Available @code{method-access-controls} fields are:
13911 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
13912 If @code{#t}, apply access controls to all methods except the listed
13913 methods. Otherwise apply to only the listed methods.
13915 Defaults to @samp{#f}.
13918 @deftypevr {@code{method-access-controls} parameter} method-list methods
13919 Methods to which this access control applies.
13921 Defaults to @samp{()}.
13924 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
13925 Access control directives, as a list of strings. Each string should be
13926 one directive, such as "Order allow,deny".
13928 Defaults to @samp{()}.
13933 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
13934 Specifies the number of debugging messages that are retained for logging
13935 if an error occurs in a print job. Debug messages are logged regardless
13936 of the LogLevel setting.
13938 Defaults to @samp{100}.
13941 @deftypevr {@code{cups-configuration} parameter} log-level log-level
13942 Specifies the level of logging for the ErrorLog file. The value
13943 @code{none} stops all logging while @code{debug2} logs everything.
13945 Defaults to @samp{info}.
13948 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
13949 Specifies the format of the date and time in the log files. The value
13950 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
13952 Defaults to @samp{standard}.
13955 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
13956 Specifies the maximum number of simultaneous clients that are allowed by
13959 Defaults to @samp{100}.
13962 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
13963 Specifies the maximum number of simultaneous clients that are allowed
13964 from a single address.
13966 Defaults to @samp{100}.
13969 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
13970 Specifies the maximum number of copies that a user can print of each
13973 Defaults to @samp{9999}.
13976 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
13977 Specifies the maximum time a job may remain in the @code{indefinite}
13978 hold state before it is canceled. A value of 0 disables cancellation of
13981 Defaults to @samp{0}.
13984 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
13985 Specifies the maximum number of simultaneous jobs that are allowed. Set
13986 to 0 to allow an unlimited number of jobs.
13988 Defaults to @samp{500}.
13991 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
13992 Specifies the maximum number of simultaneous jobs that are allowed per
13993 printer. A value of 0 allows up to MaxJobs jobs per printer.
13995 Defaults to @samp{0}.
13998 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
13999 Specifies the maximum number of simultaneous jobs that are allowed per
14000 user. A value of 0 allows up to MaxJobs jobs per user.
14002 Defaults to @samp{0}.
14005 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
14006 Specifies the maximum time a job may take to print before it is
14007 canceled, in seconds. Set to 0 to disable cancellation of "stuck" jobs.
14009 Defaults to @samp{10800}.
14012 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
14013 Specifies the maximum size of the log files before they are rotated, in
14014 bytes. The value 0 disables log rotation.
14016 Defaults to @samp{1048576}.
14019 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
14020 Specifies the maximum amount of time to allow between files in a
14021 multiple file print job, in seconds.
14023 Defaults to @samp{300}.
14026 @deftypevr {@code{cups-configuration} parameter} string page-log-format
14027 Specifies the format of PageLog lines. Sequences beginning with percent
14028 (@samp{%}) characters are replaced with the corresponding information,
14029 while all other characters are copied literally. The following percent
14030 sequences are recognized:
14034 insert a single percent character
14037 insert the value of the specified IPP attribute
14040 insert the number of copies for the current page
14043 insert the current page number
14046 insert the current date and time in common log format
14052 insert the printer name
14055 insert the username
14058 A value of the empty string disables page logging. The string @code{%p
14059 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
14060 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
14063 Defaults to @samp{""}.
14066 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
14067 Passes the specified environment variable(s) to child processes; a list
14070 Defaults to @samp{()}.
14073 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
14074 Specifies named access control policies.
14076 Available @code{policy-configuration} fields are:
14078 @deftypevr {@code{policy-configuration} parameter} string name
14079 Name of the policy.
14082 @deftypevr {@code{policy-configuration} parameter} string job-private-access
14083 Specifies an access list for a job's private values. @code{@@ACL} maps
14084 to the printer's requesting-user-name-allowed or
14085 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
14086 owner. @code{@@SYSTEM} maps to the groups listed for the
14087 @code{system-group} field of the @code{files-config} configuration,
14088 which is reified into the @code{cups-files.conf(5)} file. Other
14089 possible elements of the access list include specific user names, and
14090 @code{@@@var{group}} to indicate members of a specific group. The
14091 access list may also be simply @code{all} or @code{default}.
14093 Defaults to @samp{"@@OWNER @@SYSTEM"}.
14096 @deftypevr {@code{policy-configuration} parameter} string job-private-values
14097 Specifies the list of job values to make private, or @code{all},
14098 @code{default}, or @code{none}.
14100 Defaults to @samp{"job-name job-originating-host-name
14101 job-originating-user-name phone"}.
14104 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
14105 Specifies an access list for a subscription's private values.
14106 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
14107 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
14108 owner. @code{@@SYSTEM} maps to the groups listed for the
14109 @code{system-group} field of the @code{files-config} configuration,
14110 which is reified into the @code{cups-files.conf(5)} file. Other
14111 possible elements of the access list include specific user names, and
14112 @code{@@@var{group}} to indicate members of a specific group. The
14113 access list may also be simply @code{all} or @code{default}.
14115 Defaults to @samp{"@@OWNER @@SYSTEM"}.
14118 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
14119 Specifies the list of job values to make private, or @code{all},
14120 @code{default}, or @code{none}.
14122 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
14123 notify-subscriber-user-name notify-user-data"}.
14126 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
14127 Access control by IPP operation.
14129 Defaults to @samp{()}.
14133 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
14134 Specifies whether job files (documents) are preserved after a job is
14135 printed. If a numeric value is specified, job files are preserved for
14136 the indicated number of seconds after printing. Otherwise a boolean
14137 value applies indefinitely.
14139 Defaults to @samp{86400}.
14142 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
14143 Specifies whether the job history is preserved after a job is printed.
14144 If a numeric value is specified, the job history is preserved for the
14145 indicated number of seconds after printing. If @code{#t}, the job
14146 history is preserved until the MaxJobs limit is reached.
14148 Defaults to @samp{#t}.
14151 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
14152 Specifies the amount of time to wait for job completion before
14153 restarting the scheduler.
14155 Defaults to @samp{30}.
14158 @deftypevr {@code{cups-configuration} parameter} string rip-cache
14159 Specifies the maximum amount of memory to use when converting documents
14160 into bitmaps for a printer.
14162 Defaults to @samp{"128m"}.
14165 @deftypevr {@code{cups-configuration} parameter} string server-admin
14166 Specifies the email address of the server administrator.
14168 Defaults to @samp{"root@@localhost.localdomain"}.
14171 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
14172 The ServerAlias directive is used for HTTP Host header validation when
14173 clients connect to the scheduler from external interfaces. Using the
14174 special name @code{*} can expose your system to known browser-based DNS
14175 rebinding attacks, even when accessing sites through a firewall. If the
14176 auto-discovery of alternate names does not work, we recommend listing
14177 each alternate name with a ServerAlias directive instead of using
14180 Defaults to @samp{*}.
14183 @deftypevr {@code{cups-configuration} parameter} string server-name
14184 Specifies the fully-qualified host name of the server.
14186 Defaults to @samp{"localhost"}.
14189 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
14190 Specifies what information is included in the Server header of HTTP
14191 responses. @code{None} disables the Server header. @code{ProductOnly}
14192 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
14193 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
14194 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
14195 the output of the @code{uname} command. @code{Full} reports @code{CUPS
14196 2.0.0 (@var{uname}) IPP/2.0}.
14198 Defaults to @samp{Minimal}.
14201 @deftypevr {@code{cups-configuration} parameter} string set-env
14202 Set the specified environment variable to be passed to child processes.
14204 Defaults to @samp{"variable value"}.
14207 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
14208 Listens on the specified interfaces for encrypted connections. Valid
14209 values are of the form @var{address}:@var{port}, where @var{address} is
14210 either an IPv6 address enclosed in brackets, an IPv4 address, or
14211 @code{*} to indicate all addresses.
14213 Defaults to @samp{()}.
14216 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
14217 Sets encryption options. By default, CUPS only supports encryption
14218 using TLS v1.0 or higher using known secure cipher suites. The
14219 @code{AllowRC4} option enables the 128-bit RC4 cipher suites, which are
14220 required for some older clients that do not implement newer ones. The
14221 @code{AllowSSL3} option enables SSL v3.0, which is required for some
14222 older clients that do not support TLS v1.0.
14224 Defaults to @samp{()}.
14227 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
14228 Specifies whether the scheduler requires clients to strictly adhere to
14229 the IPP specifications.
14231 Defaults to @samp{#f}.
14234 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
14235 Specifies the HTTP request timeout, in seconds.
14237 Defaults to @samp{300}.
14241 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
14242 Specifies whether the web interface is enabled.
14244 Defaults to @samp{#f}.
14247 At this point you're probably thinking ``oh dear, Guix manual, I like
14248 you but you can stop already with the configuration options''. Indeed.
14249 However, one more point: it could be that you have an existing
14250 @code{cupsd.conf} that you want to use. In that case, you can pass an
14251 @code{opaque-cups-configuration} as the configuration of a
14252 @code{cups-service-type}.
14254 Available @code{opaque-cups-configuration} fields are:
14256 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
14260 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
14261 The contents of the @code{cupsd.conf}, as a string.
14264 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
14265 The contents of the @code{cups-files.conf} file, as a string.
14268 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
14269 strings of the same name, you could instantiate a CUPS service like
14273 (service cups-service-type
14274 (opaque-cups-configuration
14275 (cupsd.conf cupsd.conf)
14276 (cups-files.conf cups-files.conf)))
14280 @node Desktop Services
14281 @subsection Desktop Services
14283 The @code{(gnu services desktop)} module provides services that are
14284 usually useful in the context of a ``desktop'' setup---that is, on a
14285 machine running a graphical display server, possibly with graphical user
14286 interfaces, etc. It also defines services that provide specific desktop
14287 environments like GNOME, XFCE or MATE.
14289 To simplify things, the module defines a variable containing the set of
14290 services that users typically expect on a machine with a graphical
14291 environment and networking:
14293 @defvr {Scheme Variable} %desktop-services
14294 This is a list of services that builds upon @var{%base-services} and
14295 adds or adjusts services for a typical ``desktop'' setup.
14297 In particular, it adds a graphical login manager (@pxref{X Window,
14298 @code{slim-service}}), screen lockers, a network management tool
14299 (@pxref{Networking Services, @code{network-manager-service-type}}), energy and color
14300 management services, the @code{elogind} login and seat manager, the
14301 Polkit privilege service, the GeoClue location service, the
14302 AccountsService daemon that allows authorized users change system
14303 passwords, an NTP client (@pxref{Networking Services}), the Avahi
14304 daemon, and has the name service switch service configured to be able to
14305 use @code{nss-mdns} (@pxref{Name Service Switch, mDNS}).
14308 The @var{%desktop-services} variable can be used as the @code{services}
14309 field of an @code{operating-system} declaration (@pxref{operating-system
14310 Reference, @code{services}}).
14312 Additionally, the @code{gnome-desktop-service},
14313 @code{xfce-desktop-service}, @code{mate-desktop-service-type} and
14314 @code{enlightenment-desktop-service-type} procedures can add GNOME, XFCE, MATE
14315 and/or Enlightenment to a system. To ``add GNOME'' means that system-level
14316 services like the backlight adjustment helpers and the power management
14317 utilities are added to the system, extending @code{polkit} and @code{dbus}
14318 appropriately, allowing GNOME to operate with elevated privileges on a
14319 limited number of special-purpose system interfaces. Additionally,
14320 adding a service made by @code{gnome-desktop-service} adds the GNOME
14321 metapackage to the system profile. Likewise, adding the XFCE service
14322 not only adds the @code{xfce} metapackage to the system profile, but it
14323 also gives the Thunar file manager the ability to open a ``root-mode''
14324 file management window, if the user authenticates using the
14325 administrator's password via the standard polkit graphical interface.
14326 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
14327 appropriately, allowing MATE to operate with elevated privileges on a
14328 limited number of special-purpose system interfaces. Additionally,
14329 adding a service of type @code{mate-desktop-service-type} adds the MATE
14330 metapackage to the system profile. ``Adding Enlightenment'' means that
14331 @code{dbus} is extended appropriately, and several of Enlightenment's binaries
14332 are set as setuid, allowing Enlightenment's screen locker and other
14333 functionality to work as expetected.
14335 The desktop environments in Guix use the Xorg display server by
14336 default. If you'd like to use the newer display server protocol
14337 called Wayland, you need to use the @code{sddm-service} instead of the
14338 @code{slim-service} for the graphical login manager. You should then
14339 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
14340 also try starting GNOME on Wayland manually from a TTY with the
14341 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
14342 gnome-session``. Currently only GNOME has support for Wayland.
14344 @deffn {Scheme Procedure} gnome-desktop-service
14345 Return a service that adds the @code{gnome} package to the system
14346 profile, and extends polkit with the actions from
14347 @code{gnome-settings-daemon}.
14350 @deffn {Scheme Procedure} xfce-desktop-service
14351 Return a service that adds the @code{xfce} package to the system profile,
14352 and extends polkit with the ability for @code{thunar} to manipulate the
14353 file system as root from within a user session, after the user has
14354 authenticated with the administrator's password.
14357 @deffn {Scheme Variable} mate-desktop-service-type
14358 This is the type of the service that runs the @uref{https://mate-desktop.org/,
14359 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
14360 object (see below.)
14362 This service adds the @code{mate} package to the system
14363 profile, and extends polkit with the actions from
14364 @code{mate-settings-daemon}.
14367 @deftp {Data Type} mate-desktop-configuration
14368 Configuration record for the MATE desktop environment.
14371 @item @code{mate} (default @code{mate})
14372 The MATE package to use.
14376 @deffn {Scheme Variable} enlightenment-desktop-service-type
14377 Return a service that adds the @code{enlightenment} package to the system
14378 profile, and extends dbus with actions from @code{efl}.
14381 @deftp {Data Type} enlightenment-desktop-service-configuration
14383 @item @code{enlightenment} (default @code{enlightenment})
14384 The enlightenment package to use.
14388 Because the GNOME, XFCE and MATE desktop services pull in so many packages,
14389 the default @code{%desktop-services} variable doesn't include any of
14390 them by default. To add GNOME, XFCE or MATE, just @code{cons} them onto
14391 @code{%desktop-services} in the @code{services} field of your
14392 @code{operating-system}:
14395 (use-modules (gnu))
14396 (use-service-modules desktop)
14399 ;; cons* adds items to the list given as its last argument.
14400 (services (cons* (gnome-desktop-service)
14401 (xfce-desktop-service)
14402 %desktop-services))
14406 These desktop environments will then be available as options in the
14407 graphical login window.
14409 The actual service definitions included in @code{%desktop-services} and
14410 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
14411 are described below.
14413 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
14414 Return a service that runs the ``system bus'', using @var{dbus}, with
14415 support for @var{services}.
14417 @uref{http://dbus.freedesktop.org/, D-Bus} is an inter-process communication
14418 facility. Its system bus is used to allow system services to communicate
14419 and to be notified of system-wide events.
14421 @var{services} must be a list of packages that provide an
14422 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
14423 and policy files. For example, to allow avahi-daemon to use the system bus,
14424 @var{services} must be equal to @code{(list avahi)}.
14427 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
14428 Return a service that runs the @code{elogind} login and
14429 seat management daemon. @uref{https://github.com/elogind/elogind,
14430 Elogind} exposes a D-Bus interface that can be used to know which users
14431 are logged in, know what kind of sessions they have open, suspend the
14432 system, inhibit system suspend, reboot the system, and other tasks.
14434 Elogind handles most system-level power events for a computer, for
14435 example suspending the system when a lid is closed, or shutting it down
14436 when the power button is pressed.
14438 The @var{config} keyword argument specifies the configuration for
14439 elogind, and should be the result of an @code{(elogind-configuration
14440 (@var{parameter} @var{value})...)} invocation. Available parameters and
14441 their default values are:
14444 @item kill-user-processes?
14446 @item kill-only-users
14448 @item kill-exclude-users
14450 @item inhibit-delay-max-seconds
14452 @item handle-power-key
14454 @item handle-suspend-key
14456 @item handle-hibernate-key
14458 @item handle-lid-switch
14460 @item handle-lid-switch-docked
14462 @item power-key-ignore-inhibited?
14464 @item suspend-key-ignore-inhibited?
14466 @item hibernate-key-ignore-inhibited?
14468 @item lid-switch-ignore-inhibited?
14470 @item holdoff-timeout-seconds
14474 @item idle-action-seconds
14476 @item runtime-directory-size-percent
14478 @item runtime-directory-size
14482 @item suspend-state
14483 @code{("mem" "standby" "freeze")}
14486 @item hibernate-state
14488 @item hibernate-mode
14489 @code{("platform" "shutdown")}
14490 @item hybrid-sleep-state
14492 @item hybrid-sleep-mode
14493 @code{("suspend" "platform" "shutdown")}
14497 @deffn {Scheme Procedure} accountsservice-service @
14498 [#:accountsservice @var{accountsservice}]
14499 Return a service that runs AccountsService, a system service that can
14500 list available accounts, change their passwords, and so on.
14501 AccountsService integrates with PolicyKit to enable unprivileged users
14502 to acquire the capability to modify their system configuration.
14503 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
14504 accountsservice web site} for more information.
14506 The @var{accountsservice} keyword argument is the @code{accountsservice}
14507 package to expose as a service.
14510 @deffn {Scheme Procedure} polkit-service @
14511 [#:polkit @var{polkit}]
14512 Return a service that runs the
14513 @uref{http://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
14514 management service}, which allows system administrators to grant access to
14515 privileged operations in a structured way. By querying the Polkit service, a
14516 privileged system component can know when it should grant additional
14517 capabilities to ordinary users. For example, an ordinary user can be granted
14518 the capability to suspend the system if the user is logged in locally.
14521 @defvr {Scheme Variable} upower-service-type
14522 Service that runs @uref{http://upower.freedesktop.org/, @command{upowerd}}, a
14523 system-wide monitor for power consumption and battery levels, with the given
14524 configuration settings.
14526 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
14527 notably used by GNOME.
14530 @deftp {Data Type} upower-configuration
14531 Data type representation the configuration for UPower.
14535 @item @code{upower} (default: @var{upower})
14536 Package to use for @code{upower}.
14538 @item @code{watts-up-pro?} (default: @code{#f})
14539 Enable the Watts Up Pro device.
14541 @item @code{poll-batteries?} (default: @code{#t})
14542 Enable polling the kernel for battery level changes.
14544 @item @code{ignore-lid?} (default: @code{#f})
14545 Ignore the lid state, this can be useful if it's incorrect on a device.
14547 @item @code{use-percentage-for-policy?} (default: @code{#f})
14548 Whether battery percentage based policy should be used. The default is to use
14549 the time left, change to @code{#t} to use the percentage.
14551 @item @code{percentage-low} (default: @code{10})
14552 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
14553 at which the battery is considered low.
14555 @item @code{percentage-critical} (default: @code{3})
14556 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
14557 at which the battery is considered critical.
14559 @item @code{percentage-action} (default: @code{2})
14560 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
14561 at which action will be taken.
14563 @item @code{time-low} (default: @code{1200})
14564 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
14565 seconds at which the battery is considered low.
14567 @item @code{time-critical} (default: @code{300})
14568 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
14569 seconds at which the battery is considered critical.
14571 @item @code{time-action} (default: @code{120})
14572 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
14573 seconds at which action will be taken.
14575 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
14576 The action taken when @code{percentage-action} or @code{time-action} is
14577 reached (depending on the configuration of @code{use-percentage-for-policy?}).
14579 Possible values are:
14589 @code{'hybrid-sleep}.
14595 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
14596 Return a service for @uref{http://udisks.freedesktop.org/docs/latest/,
14597 UDisks}, a @dfn{disk management} daemon that provides user interfaces with
14598 notifications and ways to mount/unmount disks. Programs that talk to UDisks
14599 include the @command{udisksctl} command, part of UDisks, and GNOME Disks.
14602 @deffn {Scheme Procedure} colord-service [#:colord @var{colord}]
14603 Return a service that runs @command{colord}, a system service with a D-Bus
14604 interface to manage the color profiles of input and output devices such as
14605 screens and scanners. It is notably used by the GNOME Color Manager graphical
14606 tool. See @uref{http://www.freedesktop.org/software/colord/, the colord web
14607 site} for more information.
14610 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
14611 Return a configuration allowing an application to access GeoClue
14612 location data. @var{name} is the Desktop ID of the application, without
14613 the @code{.desktop} part. If @var{allowed?} is true, the application
14614 will have access to location information by default. The boolean
14615 @var{system?} value indicates whether an application is a system component
14616 or not. Finally @var{users} is a list of UIDs of all users for which
14617 this application is allowed location info access. An empty users list
14618 means that all users are allowed.
14621 @defvr {Scheme Variable} %standard-geoclue-applications
14622 The standard list of well-known GeoClue application configurations,
14623 granting authority to the GNOME date-and-time utility to ask for the
14624 current location in order to set the time zone, and allowing the
14625 IceCat and Epiphany web browsers to request location information.
14626 IceCat and Epiphany both query the user before allowing a web page to
14627 know the user's location.
14630 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
14631 [#:whitelist '()] @
14632 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
14633 [#:submit-data? #f]
14634 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
14635 [#:submission-nick "geoclue"] @
14636 [#:applications %standard-geoclue-applications]
14637 Return a service that runs the GeoClue location service. This service
14638 provides a D-Bus interface to allow applications to request access to a
14639 user's physical location, and optionally to add information to online
14640 location databases. See
14641 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
14642 web site} for more information.
14645 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
14646 [@w{#:auto-enable? #f}]
14647 Return a service that runs the @command{bluetoothd} daemon, which
14648 manages all the Bluetooth devices and provides a number of D-Bus
14649 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
14650 powered automatically at boot, which can be useful when using a
14651 bluetooth keyboard or mouse.
14653 Users need to be in the @code{lp} group to access the D-Bus service.
14656 @node Sound Services
14657 @subsection Sound Services
14659 @cindex sound support
14661 @cindex PulseAudio, sound support
14663 The @code{(gnu services sound)} module provides a service to configure the
14664 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
14665 preferred ALSA output driver.
14667 @deffn {Scheme Variable} alsa-service-type
14668 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
14669 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
14670 configuration file. The value for this type is a @command{alsa-configuration}
14671 record as in this example:
14674 (service alsa-service-type)
14677 See below for details about @code{alsa-configuration}.
14680 @deftp {Data Type} alsa-configuration
14681 Data type representing the configuration for @code{alsa-service}.
14684 @item @code{alsa-plugins} (default: @var{alsa-plugins})
14685 @code{alsa-plugins} package to use.
14687 @item @code{pulseaudio?} (default: @var{#t})
14688 Whether ALSA applications should transparently be made to use the
14689 @uref{http://www.pulseaudio.org/, PulseAudio} sound server.
14691 Using PulseAudio allows you to run several sound-producing applications
14692 at the same time and to individual control them @i{via}
14693 @command{pavucontrol}, among other things.
14695 @item @code{extra-options} (default: @var{""})
14696 String to append to the @file{/etc/asound.conf} file.
14701 Individual users who want to override the system configuration of ALSA can do
14702 it with the @file{~/.asoundrc} file:
14705 # In guix, we have to specify the absolute path for plugins.
14707 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
14710 # Routing ALSA to jack:
14711 # <http://jackaudio.org/faq/routing_alsa.html>.
14715 0 system:playback_1
14716 1 system:playback_2
14733 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
14737 @node Database Services
14738 @subsection Database Services
14742 The @code{(gnu services databases)} module provides the following services.
14744 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
14745 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
14746 [#:port 5432] [#:locale ``en_US.utf8''] [#:extension-packages '()]
14747 Return a service that runs @var{postgresql}, the PostgreSQL database
14750 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
14751 creates a database cluster with @var{locale} as the default
14752 locale, stored in @var{data-directory}. It then listens on @var{port}.
14754 @cindex postgresql extension-packages
14755 Additional extensions are loaded from packages listed in
14756 @var{extension-packages}. Extensions are available at runtime. For instance,
14757 to create a geographic database using the @code{postgis} extension, a user can
14758 configure the postgresql-service as in this example:
14762 (use-package-modules databases geo)
14766 ;; postgresql is required to run `psql' but postgis is not required for
14767 ;; proper operation.
14768 (packages (cons* postgresql %base-packages))
14771 (postgresql-service #:extension-packages (list postgis))
14775 Then the extension becomes visible and you can initialise an empty geographic
14776 database in this way:
14780 > create database postgistest;
14781 > \connect postgistest;
14782 > create extension postgis;
14783 > create extension postgis_topology;
14786 There is no need to add this field for contrib extensions such as hstore or
14787 dblink as they are already loadable by postgresql. This field is only
14788 required to add extensions provided by other packages.
14791 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
14792 Return a service that runs @command{mysqld}, the MySQL or MariaDB
14795 The optional @var{config} argument specifies the configuration for
14796 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
14799 @deftp {Data Type} mysql-configuration
14800 Data type representing the configuration of @var{mysql-service}.
14803 @item @code{mysql} (default: @var{mariadb})
14804 Package object of the MySQL database server, can be either @var{mariadb}
14807 For MySQL, a temporary root password will be displayed at activation time.
14808 For MariaDB, the root password is empty.
14810 @item @code{port} (default: @code{3306})
14811 TCP port on which the database server listens for incoming connections.
14815 @defvr {Scheme Variable} memcached-service-type
14816 This is the service type for the @uref{https://memcached.org/,
14817 Memcached} service, which provides a distributed in memory cache. The
14818 value for the service type is a @code{memcached-configuration} object.
14822 (service memcached-service-type)
14825 @deftp {Data Type} memcached-configuration
14826 Data type representing the configuration of memcached.
14829 @item @code{memcached} (default: @code{memcached})
14830 The Memcached package to use.
14832 @item @code{interfaces} (default: @code{'("0.0.0.0")})
14833 Network interfaces on which to listen.
14835 @item @code{tcp-port} (default: @code{11211})
14836 Port on which to accept connections on,
14838 @item @code{udp-port} (default: @code{11211})
14839 Port on which to accept UDP connections on, a value of 0 will disable
14840 listening on a UDP socket.
14842 @item @code{additional-options} (default: @code{'()})
14843 Additional command line options to pass to @code{memcached}.
14847 @defvr {Scheme Variable} mongodb-service-type
14848 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
14849 The value for the service type is a @code{mongodb-configuration} object.
14853 (service mongodb-service-type)
14856 @deftp {Data Type} mongodb-configuration
14857 Data type representing the configuration of mongodb.
14860 @item @code{mongodb} (default: @code{mongodb})
14861 The MongoDB package to use.
14863 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
14864 The configuration file for MongoDB.
14866 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
14867 This value is used to create the directory, so that it exists and is
14868 owned by the mongodb user. It should match the data-directory which
14869 MongoDB is configured to use through the configuration file.
14873 @defvr {Scheme Variable} redis-service-type
14874 This is the service type for the @uref{https://redis.io/, Redis}
14875 key/value store, whose value is a @code{redis-configuration} object.
14878 @deftp {Data Type} redis-configuration
14879 Data type representing the configuration of redis.
14882 @item @code{redis} (default: @code{redis})
14883 The Redis package to use.
14885 @item @code{bind} (default: @code{"127.0.0.1"})
14886 Network interface on which to listen.
14888 @item @code{port} (default: @code{6379})
14889 Port on which to accept connections on, a value of 0 will disable
14890 listening on a TCP socket.
14892 @item @code{working-directory} (default: @code{"/var/lib/redis"})
14893 Directory in which to store the database and related files.
14897 @node Mail Services
14898 @subsection Mail Services
14902 The @code{(gnu services mail)} module provides Guix service definitions
14903 for email services: IMAP, POP3, and LMTP servers, as well as mail
14904 transport agents (MTAs). Lots of acronyms! These services are detailed
14905 in the subsections below.
14907 @subsubheading Dovecot Service
14909 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
14910 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
14913 By default, Dovecot does not need much configuration; the default
14914 configuration object created by @code{(dovecot-configuration)} will
14915 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
14916 certificate will be generated for TLS-protected connections, though
14917 Dovecot will also listen on cleartext ports by default. There are a
14918 number of options, though, which mail administrators might need to change,
14919 and as is the case with other services, Guix allows the system
14920 administrator to specify these parameters via a uniform Scheme interface.
14922 For example, to specify that mail is located at @code{maildir~/.mail},
14923 one would instantiate the Dovecot service like this:
14926 (dovecot-service #:config
14927 (dovecot-configuration
14928 (mail-location "maildir:~/.mail")))
14931 The available configuration parameters follow. Each parameter
14932 definition is preceded by its type; for example, @samp{string-list foo}
14933 indicates that the @code{foo} parameter should be specified as a list of
14934 strings. There is also a way to specify the configuration as a string,
14935 if you have an old @code{dovecot.conf} file that you want to port over
14936 from some other system; see the end for more details.
14938 @c The following documentation was initially generated by
14939 @c (generate-documentation) in (gnu services mail). Manually maintained
14940 @c documentation is better, so we shouldn't hesitate to edit below as
14941 @c needed. However if the change you want to make to this documentation
14942 @c can be done in an automated way, it's probably easier to change
14943 @c (generate-documentation) than to make it below and have to deal with
14944 @c the churn as dovecot updates.
14946 Available @code{dovecot-configuration} fields are:
14948 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
14949 The dovecot package.
14952 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
14953 A list of IPs or hosts where to listen for connections. @samp{*}
14954 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
14955 interfaces. If you want to specify non-default ports or anything more
14956 complex, customize the address and port fields of the
14957 @samp{inet-listener} of the specific services you are interested in.
14960 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
14961 List of protocols we want to serve. Available protocols include
14962 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
14964 Available @code{protocol-configuration} fields are:
14966 @deftypevr {@code{protocol-configuration} parameter} string name
14967 The name of the protocol.
14970 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
14971 UNIX socket path to the master authentication server to find users.
14972 This is used by imap (for shared users) and lda.
14973 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
14976 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
14977 Space separated list of plugins to load.
14980 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
14981 Maximum number of IMAP connections allowed for a user from each IP
14982 address. NOTE: The username is compared case-sensitively.
14983 Defaults to @samp{10}.
14988 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
14989 List of services to enable. Available services include @samp{imap},
14990 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
14993 Available @code{service-configuration} fields are:
14995 @deftypevr {@code{service-configuration} parameter} string kind
14996 The service kind. Valid values include @code{director},
14997 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
14998 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
14999 @code{tcpwrap}, @code{quota-warning}, or anything else.
15002 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
15003 Listeners for the service. A listener is either a
15004 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
15005 an @code{inet-listener-configuration}.
15006 Defaults to @samp{()}.
15008 Available @code{unix-listener-configuration} fields are:
15010 @deftypevr {@code{unix-listener-configuration} parameter} string path
15011 Path to the file, relative to @code{base-dir} field. This is also used as
15015 @deftypevr {@code{unix-listener-configuration} parameter} string mode
15016 The access mode for the socket.
15017 Defaults to @samp{"0600"}.
15020 @deftypevr {@code{unix-listener-configuration} parameter} string user
15021 The user to own the socket.
15022 Defaults to @samp{""}.
15025 @deftypevr {@code{unix-listener-configuration} parameter} string group
15026 The group to own the socket.
15027 Defaults to @samp{""}.
15031 Available @code{fifo-listener-configuration} fields are:
15033 @deftypevr {@code{fifo-listener-configuration} parameter} string path
15034 Path to the file, relative to @code{base-dir} field. This is also used as
15038 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
15039 The access mode for the socket.
15040 Defaults to @samp{"0600"}.
15043 @deftypevr {@code{fifo-listener-configuration} parameter} string user
15044 The user to own the socket.
15045 Defaults to @samp{""}.
15048 @deftypevr {@code{fifo-listener-configuration} parameter} string group
15049 The group to own the socket.
15050 Defaults to @samp{""}.
15054 Available @code{inet-listener-configuration} fields are:
15056 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
15057 The protocol to listen for.
15060 @deftypevr {@code{inet-listener-configuration} parameter} string address
15061 The address on which to listen, or empty for all addresses.
15062 Defaults to @samp{""}.
15065 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
15066 The port on which to listen.
15069 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
15070 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
15072 Defaults to @samp{#t}.
15077 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
15078 Maximum number of simultaneous client connections per process. Once
15079 this number of connections is received, the next incoming connection
15080 will prompt Dovecot to spawn another process. If set to 0,
15081 @code{default-client-limit} is used instead.
15083 Defaults to @samp{0}.
15087 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
15088 Number of connections to handle before starting a new process.
15089 Typically the only useful values are 0 (unlimited) or 1. 1 is more
15090 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
15091 Defaults to @samp{1}.
15095 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
15096 Maximum number of processes that can exist for this service. If set to
15097 0, @code{default-process-limit} is used instead.
15099 Defaults to @samp{0}.
15103 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
15104 Number of processes to always keep waiting for more connections.
15105 Defaults to @samp{0}.
15108 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
15109 If you set @samp{service-count 0}, you probably need to grow
15111 Defaults to @samp{256000000}.
15116 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
15117 Dict configuration, as created by the @code{dict-configuration}
15120 Available @code{dict-configuration} fields are:
15122 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
15123 A list of key-value pairs that this dict should hold.
15124 Defaults to @samp{()}.
15129 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
15130 A list of passdb configurations, each one created by the
15131 @code{passdb-configuration} constructor.
15133 Available @code{passdb-configuration} fields are:
15135 @deftypevr {@code{passdb-configuration} parameter} string driver
15136 The driver that the passdb should use. Valid values include
15137 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
15139 Defaults to @samp{"pam"}.
15142 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
15143 Space separated list of arguments to the passdb driver.
15144 Defaults to @samp{""}.
15149 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
15150 List of userdb configurations, each one created by the
15151 @code{userdb-configuration} constructor.
15153 Available @code{userdb-configuration} fields are:
15155 @deftypevr {@code{userdb-configuration} parameter} string driver
15156 The driver that the userdb should use. Valid values include
15157 @samp{passwd} and @samp{static}.
15158 Defaults to @samp{"passwd"}.
15161 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
15162 Space separated list of arguments to the userdb driver.
15163 Defaults to @samp{""}.
15166 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
15167 Override fields from passwd.
15168 Defaults to @samp{()}.
15173 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
15174 Plug-in configuration, created by the @code{plugin-configuration}
15178 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
15179 List of namespaces. Each item in the list is created by the
15180 @code{namespace-configuration} constructor.
15182 Available @code{namespace-configuration} fields are:
15184 @deftypevr {@code{namespace-configuration} parameter} string name
15185 Name for this namespace.
15188 @deftypevr {@code{namespace-configuration} parameter} string type
15189 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
15190 Defaults to @samp{"private"}.
15193 @deftypevr {@code{namespace-configuration} parameter} string separator
15194 Hierarchy separator to use. You should use the same separator for
15195 all namespaces or some clients get confused. @samp{/} is usually a good
15196 one. The default however depends on the underlying mail storage
15198 Defaults to @samp{""}.
15201 @deftypevr {@code{namespace-configuration} parameter} string prefix
15202 Prefix required to access this namespace. This needs to be
15203 different for all namespaces. For example @samp{Public/}.
15204 Defaults to @samp{""}.
15207 @deftypevr {@code{namespace-configuration} parameter} string location
15208 Physical location of the mailbox. This is in the same format as
15209 mail_location, which is also the default for it.
15210 Defaults to @samp{""}.
15213 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
15214 There can be only one INBOX, and this setting defines which
15216 Defaults to @samp{#f}.
15219 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
15220 If namespace is hidden, it's not advertised to clients via NAMESPACE
15221 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
15222 useful when converting from another server with different namespaces
15223 which you want to deprecate but still keep working. For example you can
15224 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
15226 Defaults to @samp{#f}.
15229 @deftypevr {@code{namespace-configuration} parameter} boolean list?
15230 Show the mailboxes under this namespace with the LIST command. This
15231 makes the namespace visible for clients that do not support the NAMESPACE
15232 extension. The special @code{children} value lists child mailboxes, but
15233 hides the namespace prefix.
15234 Defaults to @samp{#t}.
15237 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
15238 Namespace handles its own subscriptions. If set to @code{#f}, the
15239 parent namespace handles them. The empty prefix should always have this
15241 Defaults to @samp{#t}.
15244 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
15245 List of predefined mailboxes in this namespace.
15246 Defaults to @samp{()}.
15248 Available @code{mailbox-configuration} fields are:
15250 @deftypevr {@code{mailbox-configuration} parameter} string name
15251 Name for this mailbox.
15254 @deftypevr {@code{mailbox-configuration} parameter} string auto
15255 @samp{create} will automatically create this mailbox.
15256 @samp{subscribe} will both create and subscribe to the mailbox.
15257 Defaults to @samp{"no"}.
15260 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
15261 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
15262 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
15263 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
15264 Defaults to @samp{()}.
15271 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
15272 Base directory where to store runtime data.
15273 Defaults to @samp{"/var/run/dovecot/"}.
15276 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
15277 Greeting message for clients.
15278 Defaults to @samp{"Dovecot ready."}.
15281 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
15282 List of trusted network ranges. Connections from these IPs are
15283 allowed to override their IP addresses and ports (for logging and for
15284 authentication checks). @samp{disable-plaintext-auth} is also ignored
15285 for these networks. Typically you would specify your IMAP proxy servers
15287 Defaults to @samp{()}.
15290 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
15291 List of login access check sockets (e.g.@: tcpwrap).
15292 Defaults to @samp{()}.
15295 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
15296 Show more verbose process titles (in ps). Currently shows user name
15297 and IP address. Useful for seeing who is actually using the IMAP
15298 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
15300 Defaults to @samp{#f}.
15303 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
15304 Should all processes be killed when Dovecot master process shuts down.
15305 Setting this to @code{#f} means that Dovecot can be upgraded without
15306 forcing existing client connections to close (although that could also
15307 be a problem if the upgrade is e.g.@: due to a security fix).
15308 Defaults to @samp{#t}.
15311 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
15312 If non-zero, run mail commands via this many connections to doveadm
15313 server, instead of running them directly in the same process.
15314 Defaults to @samp{0}.
15317 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
15318 UNIX socket or host:port used for connecting to doveadm server.
15319 Defaults to @samp{"doveadm-server"}.
15322 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
15323 List of environment variables that are preserved on Dovecot startup
15324 and passed down to all of its child processes. You can also give
15325 key=value pairs to always set specific settings.
15328 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
15329 Disable LOGIN command and all other plaintext authentications unless
15330 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
15331 matches the local IP (i.e.@: you're connecting from the same computer),
15332 the connection is considered secure and plaintext authentication is
15333 allowed. See also ssl=required setting.
15334 Defaults to @samp{#t}.
15337 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
15338 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
15339 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
15340 for caching to be used.
15341 Defaults to @samp{0}.
15344 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
15345 Time to live for cached data. After TTL expires the cached record
15346 is no longer used, *except* if the main database lookup returns internal
15347 failure. We also try to handle password changes automatically: If
15348 user's previous authentication was successful, but this one wasn't, the
15349 cache isn't used. For now this works only with plaintext
15351 Defaults to @samp{"1 hour"}.
15354 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
15355 TTL for negative hits (user not found, password mismatch).
15356 0 disables caching them completely.
15357 Defaults to @samp{"1 hour"}.
15360 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
15361 List of realms for SASL authentication mechanisms that need them.
15362 You can leave it empty if you don't want to support multiple realms.
15363 Many clients simply use the first one listed here, so keep the default
15365 Defaults to @samp{()}.
15368 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
15369 Default realm/domain to use if none was specified. This is used for
15370 both SASL realms and appending @@domain to username in plaintext
15372 Defaults to @samp{""}.
15375 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
15376 List of allowed characters in username. If the user-given username
15377 contains a character not listed in here, the login automatically fails.
15378 This is just an extra check to make sure user can't exploit any
15379 potential quote escaping vulnerabilities with SQL/LDAP databases. If
15380 you want to allow all characters, set this value to empty.
15381 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
15384 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
15385 Username character translations before it's looked up from
15386 databases. The value contains series of from -> to characters. For
15387 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
15388 translated to @samp{@@}.
15389 Defaults to @samp{""}.
15392 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
15393 Username formatting before it's looked up from databases. You can
15394 use the standard variables here, e.g.@: %Lu would lowercase the username,
15395 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
15396 change the @samp{@@} into @samp{-AT-}. This translation is done after
15397 @samp{auth-username-translation} changes.
15398 Defaults to @samp{"%Lu"}.
15401 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
15402 If you want to allow master users to log in by specifying the master
15403 username within the normal username string (i.e.@: not using SASL
15404 mechanism's support for it), you can specify the separator character
15405 here. The format is then <username><separator><master username>.
15406 UW-IMAP uses @samp{*} as the separator, so that could be a good
15408 Defaults to @samp{""}.
15411 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
15412 Username to use for users logging in with ANONYMOUS SASL
15414 Defaults to @samp{"anonymous"}.
15417 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
15418 Maximum number of dovecot-auth worker processes. They're used to
15419 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
15420 They're automatically created and destroyed as needed.
15421 Defaults to @samp{30}.
15424 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
15425 Host name to use in GSSAPI principal names. The default is to use
15426 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
15427 allow all keytab entries.
15428 Defaults to @samp{""}.
15431 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
15432 Kerberos keytab to use for the GSSAPI mechanism. Will use the
15433 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
15434 need to change the auth service to run as root to be able to read this
15436 Defaults to @samp{""}.
15439 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
15440 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
15441 and @samp{ntlm-auth} helper.
15442 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
15443 Defaults to @samp{#f}.
15446 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
15447 Path for Samba's @samp{ntlm-auth} helper binary.
15448 Defaults to @samp{"/usr/bin/ntlm_auth"}.
15451 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
15452 Time to delay before replying to failed authentications.
15453 Defaults to @samp{"2 secs"}.
15456 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
15457 Require a valid SSL client certificate or the authentication
15459 Defaults to @samp{#f}.
15462 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
15463 Take the username from client's SSL certificate, using
15464 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
15466 Defaults to @samp{#f}.
15469 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
15470 List of wanted authentication mechanisms. Supported mechanisms are:
15471 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
15472 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
15473 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
15474 @samp{disable-plaintext-auth} setting.
15477 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
15478 List of IPs or hostnames to all director servers, including ourself.
15479 Ports can be specified as ip:port. The default port is the same as what
15480 director service's @samp{inet-listener} is using.
15481 Defaults to @samp{()}.
15484 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
15485 List of IPs or hostnames to all backend mail servers. Ranges are
15486 allowed too, like 10.0.0.10-10.0.0.30.
15487 Defaults to @samp{()}.
15490 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
15491 How long to redirect users to a specific server after it no longer
15492 has any connections.
15493 Defaults to @samp{"15 min"}.
15496 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
15497 How the username is translated before being hashed. Useful values
15498 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
15499 are shared within domain.
15500 Defaults to @samp{"%Lu"}.
15503 @deftypevr {@code{dovecot-configuration} parameter} string log-path
15504 Log file to use for error messages. @samp{syslog} logs to syslog,
15505 @samp{/dev/stderr} logs to stderr.
15506 Defaults to @samp{"syslog"}.
15509 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
15510 Log file to use for informational messages. Defaults to
15512 Defaults to @samp{""}.
15515 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
15516 Log file to use for debug messages. Defaults to
15517 @samp{info-log-path}.
15518 Defaults to @samp{""}.
15521 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
15522 Syslog facility to use if you're logging to syslog. Usually if you
15523 don't want to use @samp{mail}, you'll use local0..local7. Also other
15524 standard facilities are supported.
15525 Defaults to @samp{"mail"}.
15528 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
15529 Log unsuccessful authentication attempts and the reasons why they
15531 Defaults to @samp{#f}.
15534 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose-passwords?
15535 In case of password mismatches, log the attempted password. Valid
15536 values are no, plain and sha1. sha1 can be useful for detecting brute
15537 force password attempts vs. user simply trying the same password over
15538 and over again. You can also truncate the value to n chars by appending
15539 ":n" (e.g.@: sha1:6).
15540 Defaults to @samp{#f}.
15543 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
15544 Even more verbose logging for debugging purposes. Shows for example
15546 Defaults to @samp{#f}.
15549 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
15550 In case of password mismatches, log the passwords and used scheme so
15551 the problem can be debugged. Enabling this also enables
15553 Defaults to @samp{#f}.
15556 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
15557 Enable mail process debugging. This can help you figure out why
15558 Dovecot isn't finding your mails.
15559 Defaults to @samp{#f}.
15562 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
15563 Show protocol level SSL errors.
15564 Defaults to @samp{#f}.
15567 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
15568 Prefix for each line written to log file. % codes are in
15569 strftime(3) format.
15570 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
15573 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
15574 List of elements we want to log. The elements which have a
15575 non-empty variable value are joined together to form a comma-separated
15579 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
15580 Login log format. %s contains @samp{login-log-format-elements}
15581 string, %$ contains the data we want to log.
15582 Defaults to @samp{"%$: %s"}.
15585 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
15586 Log prefix for mail processes. See doc/wiki/Variables.txt for list
15587 of possible variables you can use.
15588 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
15591 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
15592 Format to use for logging mail deliveries. You can use variables:
15595 Delivery status message (e.g.@: @samp{saved to INBOX})
15607 Defaults to @samp{"msgid=%m: %$"}.
15610 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
15611 Location for users' mailboxes. The default is empty, which means
15612 that Dovecot tries to find the mailboxes automatically. This won't work
15613 if the user doesn't yet have any mail, so you should explicitly tell
15614 Dovecot the full location.
15616 If you're using mbox, giving a path to the INBOX
15617 file (e.g.@: /var/mail/%u) isn't enough. You'll also need to tell Dovecot
15618 where the other mailboxes are kept. This is called the "root mail
15619 directory", and it must be the first path given in the
15620 @samp{mail-location} setting.
15622 There are a few special variables you can use, eg.:
15628 user part in user@@domain, same as %u if there's no domain
15630 domain part in user@@domain, empty if there's no domain
15635 See doc/wiki/Variables.txt for full list. Some examples:
15637 @item maildir:~/Maildir
15638 @item mbox:~/mail:INBOX=/var/mail/%u
15639 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
15641 Defaults to @samp{""}.
15644 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
15645 System user and group used to access mails. If you use multiple,
15646 userdb can override these by returning uid or gid fields. You can use
15647 either numbers or names. <doc/wiki/UserIds.txt>.
15648 Defaults to @samp{""}.
15651 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
15653 Defaults to @samp{""}.
15656 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
15657 Group to enable temporarily for privileged operations. Currently
15658 this is used only with INBOX when either its initial creation or
15659 dotlocking fails. Typically this is set to "mail" to give access to
15661 Defaults to @samp{""}.
15664 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
15665 Grant access to these supplementary groups for mail processes.
15666 Typically these are used to set up access to shared mailboxes. Note
15667 that it may be dangerous to set these if users can create
15668 symlinks (e.g.@: if "mail" group is set here, ln -s /var/mail ~/mail/var
15669 could allow a user to delete others' mailboxes, or ln -s
15670 /secret/shared/box ~/mail/mybox would allow reading it).
15671 Defaults to @samp{""}.
15674 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
15675 Allow full file system access to clients. There's no access checks
15676 other than what the operating system does for the active UID/GID. It
15677 works with both maildir and mboxes, allowing you to prefix mailboxes
15678 names with e.g.@: /path/ or ~user/.
15679 Defaults to @samp{#f}.
15682 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
15683 Don't use mmap() at all. This is required if you store indexes to
15684 shared file systems (NFS or clustered file system).
15685 Defaults to @samp{#f}.
15688 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
15689 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
15690 supports @samp{O_EXCL} since version 3, so this should be safe to use
15691 nowadays by default.
15692 Defaults to @samp{#t}.
15695 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
15696 When to use fsync() or fdatasync() calls:
15699 Whenever necessary to avoid losing important data
15701 Useful with e.g.@: NFS when write()s are delayed
15703 Never use it (best performance, but crashes can lose data).
15705 Defaults to @samp{"optimized"}.
15708 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
15709 Mail storage exists in NFS. Set this to yes to make Dovecot flush
15710 NFS caches whenever needed. If you're using only a single mail server
15712 Defaults to @samp{#f}.
15715 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
15716 Mail index files also exist in NFS. Setting this to yes requires
15717 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
15718 Defaults to @samp{#f}.
15721 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
15722 Locking method for index files. Alternatives are fcntl, flock and
15723 dotlock. Dotlocking uses some tricks which may create more disk I/O
15724 than other locking methods. NFS users: flock doesn't work, remember to
15725 change @samp{mmap-disable}.
15726 Defaults to @samp{"fcntl"}.
15729 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
15730 Directory in which LDA/LMTP temporarily stores incoming mails >128
15732 Defaults to @samp{"/tmp"}.
15735 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
15736 Valid UID range for users. This is mostly to make sure that users can't
15737 log in as daemons or other system users. Note that denying root logins is
15738 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
15740 Defaults to @samp{500}.
15743 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
15745 Defaults to @samp{0}.
15748 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
15749 Valid GID range for users. Users having non-valid GID as primary group ID
15750 aren't allowed to log in. If user belongs to supplementary groups with
15751 non-valid GIDs, those groups are not set.
15752 Defaults to @samp{1}.
15755 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
15757 Defaults to @samp{0}.
15760 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
15761 Maximum allowed length for mail keyword name. It's only forced when
15762 trying to create new keywords.
15763 Defaults to @samp{50}.
15766 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
15767 List of directories under which chrooting is allowed for mail
15768 processes (i.e.@: /var/mail will allow chrooting to /var/mail/foo/bar
15769 too). This setting doesn't affect @samp{login-chroot}
15770 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
15771 "/./" in home dirs are ignored. WARNING: Never add directories here
15772 which local users can modify, that may lead to root exploit. Usually
15773 this should be done only if you don't allow shell access for users.
15774 <doc/wiki/Chrooting.txt>.
15775 Defaults to @samp{()}.
15778 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
15779 Default chroot directory for mail processes. This can be overridden
15780 for specific users in user database by giving /./ in user's home
15781 directory (e.g.@: /home/./user chroots into /home). Note that usually
15782 there is no real need to do chrooting, Dovecot doesn't allow users to
15783 access files outside their mail directory anyway. If your home
15784 directories are prefixed with the chroot directory, append "/."@: to
15785 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
15786 Defaults to @samp{""}.
15789 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
15790 UNIX socket path to master authentication server to find users.
15791 This is used by imap (for shared users) and lda.
15792 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
15795 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
15796 Directory where to look up mail plugins.
15797 Defaults to @samp{"/usr/lib/dovecot"}.
15800 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
15801 List of plugins to load for all services. Plugins specific to IMAP,
15802 LDA, etc.@: are added to this list in their own .conf files.
15803 Defaults to @samp{()}.
15806 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
15807 The minimum number of mails in a mailbox before updates are done to
15808 cache file. This allows optimizing Dovecot's behavior to do less disk
15809 writes at the cost of more disk reads.
15810 Defaults to @samp{0}.
15813 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
15814 When IDLE command is running, mailbox is checked once in a while to
15815 see if there are any new mails or other changes. This setting defines
15816 the minimum time to wait between those checks. Dovecot can also use
15817 dnotify, inotify and kqueue to find out immediately when changes
15819 Defaults to @samp{"30 secs"}.
15822 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
15823 Save mails with CR+LF instead of plain LF. This makes sending those
15824 mails take less CPU, especially with sendfile() syscall with Linux and
15825 FreeBSD. But it also creates a bit more disk I/O which may just make it
15826 slower. Also note that if other software reads the mboxes/maildirs,
15827 they may handle the extra CRs wrong and cause problems.
15828 Defaults to @samp{#f}.
15831 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
15832 By default LIST command returns all entries in maildir beginning
15833 with a dot. Enabling this option makes Dovecot return only entries
15834 which are directories. This is done by stat()ing each entry, so it
15835 causes more disk I/O.
15836 (For systems setting struct @samp{dirent->d_type} this check is free
15837 and it's done always regardless of this setting).
15838 Defaults to @samp{#f}.
15841 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
15842 When copying a message, do it with hard links whenever possible.
15843 This makes the performance much better, and it's unlikely to have any
15845 Defaults to @samp{#t}.
15848 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
15849 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
15850 directory only when its mtime changes unexpectedly or when we can't find
15851 the mail otherwise.
15852 Defaults to @samp{#f}.
15855 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
15856 Which locking methods to use for locking mbox. There are four
15861 Create <mailbox>.lock file. This is the oldest and most NFS-safe
15862 solution. If you want to use /var/mail/ like directory, the users will
15863 need write access to that directory.
15865 Same as dotlock, but if it fails because of permissions or because there
15866 isn't enough disk space, just skip it.
15868 Use this if possible. Works with NFS too if lockd is used.
15870 May not exist in all systems. Doesn't work with NFS.
15872 May not exist in all systems. Doesn't work with NFS.
15875 You can use multiple locking methods; if you do the order they're declared
15876 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
15877 locking methods as well. Some operating systems don't allow using some of
15878 them simultaneously.
15881 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
15885 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
15886 Maximum time to wait for lock (all of them) before aborting.
15887 Defaults to @samp{"5 mins"}.
15890 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
15891 If dotlock exists but the mailbox isn't modified in any way,
15892 override the lock file after this much time.
15893 Defaults to @samp{"2 mins"}.
15896 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
15897 When mbox changes unexpectedly we have to fully read it to find out
15898 what changed. If the mbox is large this can take a long time. Since
15899 the change is usually just a newly appended mail, it'd be faster to
15900 simply read the new mails. If this setting is enabled, Dovecot does
15901 this but still safely fallbacks to re-reading the whole mbox file
15902 whenever something in mbox isn't how it's expected to be. The only real
15903 downside to this setting is that if some other MUA changes message
15904 flags, Dovecot doesn't notice it immediately. Note that a full sync is
15905 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
15906 Defaults to @samp{#t}.
15909 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
15910 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
15911 EXAMINE, EXPUNGE or CHECK commands. If this is set,
15912 @samp{mbox-dirty-syncs} is ignored.
15913 Defaults to @samp{#f}.
15916 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
15917 Delay writing mbox headers until doing a full write sync (EXPUNGE
15918 and CHECK commands and when closing the mailbox). This is especially
15919 useful for POP3 where clients often delete all mails. The downside is
15920 that our changes aren't immediately visible to other MUAs.
15921 Defaults to @samp{#t}.
15924 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
15925 If mbox size is smaller than this (e.g.@: 100k), don't write index
15926 files. If an index file already exists it's still read, just not
15928 Defaults to @samp{0}.
15931 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
15932 Maximum dbox file size until it's rotated.
15933 Defaults to @samp{10000000}.
15936 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
15937 Maximum dbox file age until it's rotated. Typically in days. Day
15938 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
15940 Defaults to @samp{"1d"}.
15943 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
15944 When creating new mdbox files, immediately preallocate their size to
15945 @samp{mdbox-rotate-size}. This setting currently works only in Linux
15946 with some file systems (ext4, xfs).
15947 Defaults to @samp{#f}.
15950 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
15951 sdbox and mdbox support saving mail attachments to external files,
15952 which also allows single instance storage for them. Other backends
15953 don't support this for now.
15955 WARNING: This feature hasn't been tested much yet. Use at your own risk.
15957 Directory root where to store mail attachments. Disabled, if empty.
15958 Defaults to @samp{""}.
15961 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
15962 Attachments smaller than this aren't saved externally. It's also
15963 possible to write a plugin to disable saving specific attachments
15965 Defaults to @samp{128000}.
15968 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
15969 File system backend to use for saving attachments:
15972 No SiS done by Dovecot (but this might help FS's own deduplication)
15974 SiS with immediate byte-by-byte comparison during saving
15975 @item sis-queue posix
15976 SiS with delayed comparison and deduplication.
15978 Defaults to @samp{"sis posix"}.
15981 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
15982 Hash format to use in attachment filenames. You can add any text and
15983 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
15984 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
15985 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
15986 Defaults to @samp{"%@{sha1@}"}.
15989 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
15991 Defaults to @samp{100}.
15994 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
15996 Defaults to @samp{1000}.
15999 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
16000 Default VSZ (virtual memory size) limit for service processes.
16001 This is mainly intended to catch and kill processes that leak memory
16002 before they eat up everything.
16003 Defaults to @samp{256000000}.
16006 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
16007 Login user is internally used by login processes. This is the most
16008 untrusted user in Dovecot system. It shouldn't have access to anything
16010 Defaults to @samp{"dovenull"}.
16013 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
16014 Internal user is used by unprivileged processes. It should be
16015 separate from login user, so that login processes can't disturb other
16017 Defaults to @samp{"dovecot"}.
16020 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
16021 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
16022 Defaults to @samp{"required"}.
16025 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
16026 PEM encoded X.509 SSL/TLS certificate (public key).
16027 Defaults to @samp{"</etc/dovecot/default.pem"}.
16030 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
16031 PEM encoded SSL/TLS private key. The key is opened before
16032 dropping root privileges, so keep the key file unreadable by anyone but
16034 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
16037 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
16038 If key file is password protected, give the password here.
16039 Alternatively give it when starting dovecot with -p parameter. Since
16040 this file is often world-readable, you may want to place this setting
16041 instead to a different.
16042 Defaults to @samp{""}.
16045 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
16046 PEM encoded trusted certificate authority. Set this only if you
16047 intend to use @samp{ssl-verify-client-cert? #t}. The file should
16048 contain the CA certificate(s) followed by the matching
16049 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
16050 Defaults to @samp{""}.
16053 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
16054 Require that CRL check succeeds for client certificates.
16055 Defaults to @samp{#t}.
16058 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
16059 Request client to send a certificate. If you also want to require
16060 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
16061 Defaults to @samp{#f}.
16064 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
16065 Which field from certificate to use for username. commonName and
16066 x500UniqueIdentifier are the usual choices. You'll also need to set
16067 @samp{auth-ssl-username-from-cert? #t}.
16068 Defaults to @samp{"commonName"}.
16071 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
16072 Minimum SSL protocol version to accept.
16073 Defaults to @samp{"TLSv1"}.
16076 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
16077 SSL ciphers to use.
16078 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
16081 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
16082 SSL crypto device to use, for valid values run "openssl engine".
16083 Defaults to @samp{""}.
16086 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
16087 Address to use when sending rejection mails.
16088 %d expands to recipient domain.
16089 Defaults to @samp{"postmaster@@%d"}.
16092 @deftypevr {@code{dovecot-configuration} parameter} string hostname
16093 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
16094 and in LMTP replies. Default is the system's real hostname@@domain.
16095 Defaults to @samp{""}.
16098 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
16099 If user is over quota, return with temporary failure instead of
16101 Defaults to @samp{#f}.
16104 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
16105 Binary to use for sending mails.
16106 Defaults to @samp{"/usr/sbin/sendmail"}.
16109 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
16110 If non-empty, send mails via this SMTP host[:port] instead of
16112 Defaults to @samp{""}.
16115 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
16116 Subject: header to use for rejection mails. You can use the same
16117 variables as for @samp{rejection-reason} below.
16118 Defaults to @samp{"Rejected: %s"}.
16121 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
16122 Human readable error message for rejection mails. You can use
16135 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
16138 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
16139 Delimiter character between local-part and detail in email
16141 Defaults to @samp{"+"}.
16144 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
16145 Header where the original recipient address (SMTP's RCPT TO:
16146 address) is taken from if not available elsewhere. With dovecot-lda -a
16147 parameter overrides this. A commonly used header for this is
16149 Defaults to @samp{""}.
16152 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
16153 Should saving a mail to a nonexistent mailbox automatically create
16155 Defaults to @samp{#f}.
16158 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
16159 Should automatically created mailboxes be also automatically
16161 Defaults to @samp{#f}.
16164 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
16165 Maximum IMAP command line length. Some clients generate very long
16166 command lines with huge mailboxes, so you may need to raise this if you
16167 get "Too long argument" or "IMAP command line too large" errors
16169 Defaults to @samp{64000}.
16172 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
16173 IMAP logout format string:
16176 total number of bytes read from client
16178 total number of bytes sent to client.
16180 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
16181 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@}"}.
16184 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
16185 Override the IMAP CAPABILITY response. If the value begins with '+',
16186 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
16187 Defaults to @samp{""}.
16190 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
16191 How long to wait between "OK Still here" notifications when client
16193 Defaults to @samp{"2 mins"}.
16196 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
16197 ID field names and values to send to clients. Using * as the value
16198 makes Dovecot use the default value. The following fields have default
16199 values currently: name, version, os, os-version, support-url,
16201 Defaults to @samp{""}.
16204 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
16205 ID fields sent by client to log. * means everything.
16206 Defaults to @samp{""}.
16209 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
16210 Workarounds for various client bugs:
16213 @item delay-newmail
16214 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
16215 CHECK commands. Some clients ignore them otherwise, for example OSX
16216 Mail (<v2.1). Outlook Express breaks more badly though, without this it
16217 may show user "Message no longer in server" errors. Note that OE6
16218 still breaks even with this workaround if synchronization is set to
16221 @item tb-extra-mailbox-sep
16222 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
16223 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
16224 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
16226 @item tb-lsub-flags
16227 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
16228 This makes Thunderbird realize they aren't selectable and show them
16229 greyed out, instead of only later giving "not selectable" popup error.
16231 Defaults to @samp{()}.
16234 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
16235 Host allowed in URLAUTH URLs sent by client. "*" allows all.
16236 Defaults to @samp{""}.
16240 Whew! Lots of configuration options. The nice thing about it though is
16241 that Guix has a complete interface to Dovecot's configuration
16242 language. This allows not only a nice way to declare configurations,
16243 but also offers reflective capabilities as well: users can write code to
16244 inspect and transform configurations from within Scheme.
16246 However, it could be that you just want to get a @code{dovecot.conf} up
16247 and running. In that case, you can pass an
16248 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
16249 @code{dovecot-service}. As its name indicates, an opaque configuration
16250 does not have easy reflective capabilities.
16252 Available @code{opaque-dovecot-configuration} fields are:
16254 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
16255 The dovecot package.
16258 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
16259 The contents of the @code{dovecot.conf}, as a string.
16262 For example, if your @code{dovecot.conf} is just the empty string, you
16263 could instantiate a dovecot service like this:
16266 (dovecot-service #:config
16267 (opaque-dovecot-configuration
16271 @subsubheading OpenSMTPD Service
16273 @deffn {Scheme Variable} opensmtpd-service-type
16274 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
16275 service, whose value should be an @code{opensmtpd-configuration} object
16276 as in this example:
16279 (service opensmtpd-service-type
16280 (opensmtpd-configuration
16281 (config-file (local-file "./my-smtpd.conf"))))
16285 @deftp {Data Type} opensmtpd-configuration
16286 Data type representing the configuration of opensmtpd.
16289 @item @code{package} (default: @var{opensmtpd})
16290 Package object of the OpenSMTPD SMTP server.
16292 @item @code{config-file} (default: @var{%default-opensmtpd-file})
16293 File-like object of the OpenSMTPD configuration file to use. By default
16294 it listens on the loopback network interface, and allows for mail from
16295 users and daemons on the local machine, as well as permitting email to
16296 remote servers. Run @command{man smtpd.conf} for more information.
16301 @subsubheading Exim Service
16303 @cindex mail transfer agent (MTA)
16304 @cindex MTA (mail transfer agent)
16307 @deffn {Scheme Variable} exim-service-type
16308 This is the type of the @uref{https://exim.org, Exim} mail transfer
16309 agent (MTA), whose value should be an @code{exim-configuration} object
16310 as in this example:
16313 (service exim-service-type
16314 (exim-configuration
16315 (config-file (local-file "./my-exim.conf"))))
16319 In order to use an @code{exim-service-type} service you must also have a
16320 @code{mail-aliases-service-type} service present in your
16321 @code{operating-system} (even if it has no aliases).
16323 @deftp {Data Type} exim-configuration
16324 Data type representing the configuration of exim.
16327 @item @code{package} (default: @var{exim})
16328 Package object of the Exim server.
16330 @item @code{config-file} (default: @code{#f})
16331 File-like object of the Exim configuration file to use. If its value is
16332 @code{#f} then use the default configuration file from the package
16333 provided in @code{package}. The resulting configuration file is loaded
16334 after setting the @code{exim_user} and @code{exim_group} configuration
16340 @subsubheading Mail Aliases Service
16342 @cindex email aliases
16343 @cindex aliases, for email addresses
16345 @deffn {Scheme Variable} mail-aliases-service-type
16346 This is the type of the service which provides @code{/etc/aliases},
16347 specifying how to deliver mail to users on this system.
16350 (service mail-aliases-service-type
16351 '(("postmaster" "bob")
16352 ("bob" "bob@@example.com" "bob@@example2.com")))
16356 The configuration for a @code{mail-aliases-service-type} service is an
16357 association list denoting how to deliver mail that comes to this
16358 system. Each entry is of the form @code{(alias addresses ...)}, with
16359 @code{alias} specifying the local alias and @code{addresses} specifying
16360 where to deliver this user's mail.
16362 The aliases aren't required to exist as users on the local system. In
16363 the above example, there doesn't need to be a @code{postmaster} entry in
16364 the @code{operating-system}'s @code{user-accounts} in order to deliver
16365 the @code{postmaster} mail to @code{bob} (which subsequently would
16366 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
16368 @node Messaging Services
16369 @subsection Messaging Services
16374 The @code{(gnu services messaging)} module provides Guix service
16375 definitions for messaging services: currently only Prosody is supported.
16377 @subsubheading Prosody Service
16379 @deffn {Scheme Variable} prosody-service-type
16380 This is the type for the @uref{https://prosody.im, Prosody XMPP
16381 communication server}. Its value must be a @code{prosody-configuration}
16382 record as in this example:
16385 (service prosody-service-type
16386 (prosody-configuration
16387 (modules-enabled (cons "groups" "mam" %default-modules-enabled))
16390 (int-component-configuration
16391 (hostname "conference.example.net")
16393 (mod-muc (mod-muc-configuration)))))
16396 (virtualhost-configuration
16397 (domain "example.net"))))))
16400 See below for details about @code{prosody-configuration}.
16404 By default, Prosody does not need much configuration. Only one
16405 @code{virtualhosts} field is needed: it specifies the domain you wish
16408 You can perform various sanity checks on the generated configuration
16409 with the @code{prosodyctl check} command.
16411 Prosodyctl will also help you to import certificates from the
16412 @code{letsencrypt} directory so that the @code{prosody} user can access
16413 them. See @url{https://prosody.im/doc/letsencrypt}.
16416 prosodyctl --root cert import /etc/letsencrypt/live
16419 The available configuration parameters follow. Each parameter
16420 definition is preceded by its type; for example, @samp{string-list foo}
16421 indicates that the @code{foo} parameter should be specified as a list of
16422 strings. Types starting with @code{maybe-} denote parameters that won't
16423 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
16425 There is also a way to specify the configuration as a string, if you
16426 have an old @code{prosody.cfg.lua} file that you want to port over from
16427 some other system; see the end for more details.
16429 The @code{file-object} type designates either a file-like object
16430 (@pxref{G-Expressions, file-like objects}) or a file name.
16432 @c The following documentation was initially generated by
16433 @c (generate-documentation) in (gnu services messaging). Manually maintained
16434 @c documentation is better, so we shouldn't hesitate to edit below as
16435 @c needed. However if the change you want to make to this documentation
16436 @c can be done in an automated way, it's probably easier to change
16437 @c (generate-documentation) than to make it below and have to deal with
16438 @c the churn as Prosody updates.
16440 Available @code{prosody-configuration} fields are:
16442 @deftypevr {@code{prosody-configuration} parameter} package prosody
16443 The Prosody package.
16446 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
16447 Location of the Prosody data storage directory. See
16448 @url{https://prosody.im/doc/configure}.
16449 Defaults to @samp{"/var/lib/prosody"}.
16452 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
16453 Additional plugin directories. They are searched in all the specified
16454 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
16455 Defaults to @samp{()}.
16458 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
16459 Every virtual host and component needs a certificate so that clients and
16460 servers can securely verify its identity. Prosody will automatically load
16461 certificates/keys from the directory specified here.
16462 Defaults to @samp{"/etc/prosody/certs"}.
16465 @deftypevr {@code{prosody-configuration} parameter} string-list admins
16466 This is a list of accounts that are admins for the server. Note that you
16467 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
16468 @url{https://prosody.im/doc/creating_accounts}.
16469 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
16470 Defaults to @samp{()}.
16473 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
16474 Enable use of libevent for better performance under high load. See
16475 @url{https://prosody.im/doc/libevent}.
16476 Defaults to @samp{#f}.
16479 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
16480 This is the list of modules Prosody will load on startup. It looks for
16481 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
16482 Documentation on modules can be found at:
16483 @url{https://prosody.im/doc/modules}.
16484 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
16487 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
16488 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
16489 should you want to disable them then add them to this list.
16490 Defaults to @samp{()}.
16493 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
16494 Path to a text file where the shared groups are defined. If this path is
16495 empty then @samp{mod_groups} does nothing. See
16496 @url{https://prosody.im/doc/modules/mod_groups}.
16497 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
16500 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
16501 Disable account creation by default, for security. See
16502 @url{https://prosody.im/doc/creating_accounts}.
16503 Defaults to @samp{#f}.
16506 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
16507 These are the SSL/TLS-related settings. Most of them are disabled so to
16508 use Prosody's defaults. If you do not completely understand these options, do
16509 not add them to your config, it is easy to lower the security of your server
16510 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
16512 Available @code{ssl-configuration} fields are:
16514 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
16515 This determines what handshake to use.
16518 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
16519 Path to your private key file.
16522 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
16523 Path to your certificate file.
16526 @deftypevr {@code{ssl-configuration} parameter} file-object capath
16527 Path to directory containing root certificates that you wish Prosody to
16528 trust when verifying the certificates of remote servers.
16529 Defaults to @samp{"/etc/ssl/certs"}.
16532 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
16533 Path to a file containing root certificates that you wish Prosody to trust.
16534 Similar to @code{capath} but with all certificates concatenated together.
16537 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
16538 A list of verification options (these mostly map to OpenSSL's
16539 @code{set_verify()} flags).
16542 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
16543 A list of general options relating to SSL/TLS. These map to OpenSSL's
16544 @code{set_options()}. For a full list of options available in LuaSec, see the
16548 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
16549 How long a chain of certificate authorities to check when looking for a
16550 trusted root certificate.
16553 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
16554 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
16555 clients, and in what order.
16558 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
16559 A path to a file containing parameters for Diffie-Hellman key exchange. You
16560 can create such a file with:
16561 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
16564 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
16565 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
16566 @samp{"secp384r1"}.
16569 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
16570 A list of "extra" verification options.
16573 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
16574 Password for encrypted private keys.
16579 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
16580 Whether to force all client-to-server connections to be encrypted or not.
16581 See @url{https://prosody.im/doc/modules/mod_tls}.
16582 Defaults to @samp{#f}.
16585 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
16586 Set of mechanisms that will never be offered. See
16587 @url{https://prosody.im/doc/modules/mod_saslauth}.
16588 Defaults to @samp{("DIGEST-MD5")}.
16591 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
16592 Whether to force all server-to-server connections to be encrypted or not.
16593 See @url{https://prosody.im/doc/modules/mod_tls}.
16594 Defaults to @samp{#f}.
16597 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
16598 Whether to require encryption and certificate authentication. This
16599 provides ideal security, but requires servers you communicate with to support
16600 encryption AND present valid, trusted certificates. See
16601 @url{https://prosody.im/doc/s2s#security}.
16602 Defaults to @samp{#f}.
16605 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
16606 Many servers don't support encryption or have invalid or self-signed
16607 certificates. You can list domains here that will not be required to
16608 authenticate using certificates. They will be authenticated using DNS. See
16609 @url{https://prosody.im/doc/s2s#security}.
16610 Defaults to @samp{()}.
16613 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
16614 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
16615 valid certificates for some domains by specifying a list here. See
16616 @url{https://prosody.im/doc/s2s#security}.
16617 Defaults to @samp{()}.
16620 @deftypevr {@code{prosody-configuration} parameter} string authentication
16621 Select the authentication backend to use. The default provider stores
16622 passwords in plaintext and uses Prosody's configured data storage to store the
16623 authentication data. If you do not trust your server please see
16624 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
16625 about using the hashed backend. See also
16626 @url{https://prosody.im/doc/authentication}
16627 Defaults to @samp{"internal_plain"}.
16630 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
16631 Set logging options. Advanced logging configuration is not yet supported
16632 by the Prosody service. See @url{https://prosody.im/doc/logging}.
16633 Defaults to @samp{"*syslog"}.
16636 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
16637 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
16638 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
16641 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
16642 Maximum allowed size of the HTTP body (in bytes).
16645 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
16646 Some modules expose their own URL in various ways. This URL is built
16647 from the protocol, host and port used. If Prosody sits behind a proxy, the
16648 public URL will be @code{http-external-url} instead. See
16649 @url{https://prosody.im/doc/http#external_url}.
16652 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
16653 A host in Prosody is a domain on which user accounts can be created. For
16654 example if you want your users to have addresses like
16655 @samp{"john.smith@@example.com"} then you need to add a host
16656 @samp{"example.com"}. All options in this list will apply only to this host.
16658 Note: the name "virtual" host is used in configuration to avoid confusion with
16659 the actual physical host that Prosody is installed on. A single Prosody
16660 instance can serve many domains, each one defined as a VirtualHost entry in
16661 Prosody's configuration. Conversely a server that hosts a single domain would
16662 have just one VirtualHost entry.
16664 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
16666 Available @code{virtualhost-configuration} fields are:
16668 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:
16669 @deftypevr {@code{virtualhost-configuration} parameter} string domain
16670 Domain you wish Prosody to serve.
16675 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
16676 Components are extra services on a server which are available to clients,
16677 usually on a subdomain of the main server (such as
16678 @samp{"mycomponent.example.com"}). Example components might be chatroom
16679 servers, user directories, or gateways to other protocols.
16681 Internal components are implemented with Prosody-specific plugins. To add an
16682 internal component, you simply fill the hostname field, and the plugin you wish
16683 to use for the component.
16685 See @url{https://prosody.im/doc/components}.
16686 Defaults to @samp{()}.
16688 Available @code{int-component-configuration} fields are:
16690 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:
16691 @deftypevr {@code{int-component-configuration} parameter} string hostname
16692 Hostname of the component.
16695 @deftypevr {@code{int-component-configuration} parameter} string plugin
16696 Plugin you wish to use for the component.
16699 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
16700 Multi-user chat (MUC) is Prosody's module for allowing you to create
16701 hosted chatrooms/conferences for XMPP users.
16703 General information on setting up and using multi-user chatrooms can be found
16704 in the "Chatrooms" documentation (@url{https://prosody.im/doc/chatrooms}),
16705 which you should read if you are new to XMPP chatrooms.
16707 See also @url{https://prosody.im/doc/modules/mod_muc}.
16709 Available @code{mod-muc-configuration} fields are:
16711 @deftypevr {@code{mod-muc-configuration} parameter} string name
16712 The name to return in service discovery responses.
16713 Defaults to @samp{"Prosody Chatrooms"}.
16716 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
16717 If @samp{#t}, this will only allow admins to create new chatrooms.
16718 Otherwise anyone can create a room. The value @samp{"local"} restricts room
16719 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
16720 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
16721 restricts to service administrators only.
16722 Defaults to @samp{#f}.
16725 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
16726 Maximum number of history messages that will be sent to the member that has
16727 just joined the room.
16728 Defaults to @samp{20}.
16735 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
16736 External components use XEP-0114, which most standalone components
16737 support. To add an external component, you simply fill the hostname field. See
16738 @url{https://prosody.im/doc/components}.
16739 Defaults to @samp{()}.
16741 Available @code{ext-component-configuration} fields are:
16743 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:
16744 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
16745 Password which the component will use to log in.
16748 @deftypevr {@code{ext-component-configuration} parameter} string hostname
16749 Hostname of the component.
16754 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
16755 Port(s) Prosody listens on for component connections.
16756 Defaults to @samp{(5347)}.
16759 @deftypevr {@code{prosody-configuration} parameter} string component-interface
16760 Interface Prosody listens on for component connections.
16761 Defaults to @samp{"127.0.0.1"}.
16764 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
16765 Raw content that will be added to the configuration file.
16768 It could be that you just want to get a @code{prosody.cfg.lua}
16769 up and running. In that case, you can pass an
16770 @code{opaque-prosody-configuration} record as the value of
16771 @code{prosody-service-type}. As its name indicates, an opaque configuration
16772 does not have easy reflective capabilities.
16773 Available @code{opaque-prosody-configuration} fields are:
16775 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
16776 The prosody package.
16779 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
16780 The contents of the @code{prosody.cfg.lua} to use.
16783 For example, if your @code{prosody.cfg.lua} is just the empty
16784 string, you could instantiate a prosody service like this:
16787 (service prosody-service-type
16788 (opaque-prosody-configuration
16789 (prosody.cfg.lua "")))
16792 @c end of Prosody auto-generated documentation
16794 @subsubheading BitlBee Service
16796 @cindex IRC (Internet Relay Chat)
16797 @cindex IRC gateway
16798 @url{http://bitlbee.org,BitlBee} is a gateway that provides an IRC
16799 interface to a variety of messaging protocols such as XMPP.
16801 @defvr {Scheme Variable} bitlbee-service-type
16802 This is the service type for the @url{http://bitlbee.org,BitlBee} IRC
16803 gateway daemon. Its value is a @code{bitlbee-configuration} (see
16806 To have BitlBee listen on port 6667 on localhost, add this line to your
16810 (service bitlbee-service-type)
16814 @deftp {Data Type} bitlbee-configuration
16815 This is the configuration for BitlBee, with the following fields:
16818 @item @code{interface} (default: @code{"127.0.0.1"})
16819 @itemx @code{port} (default: @code{6667})
16820 Listen on the network interface corresponding to the IP address
16821 specified in @var{interface}, on @var{port}.
16823 When @var{interface} is @code{127.0.0.1}, only local clients can
16824 connect; when it is @code{0.0.0.0}, connections can come from any
16825 networking interface.
16827 @item @code{package} (default: @code{bitlbee})
16828 The BitlBee package to use.
16830 @item @code{plugins} (default: @code{'()})
16831 List of plugin packages to use---e.g., @code{bitlbee-discord}.
16833 @item @code{extra-settings} (default: @code{""})
16834 Configuration snippet added as-is to the BitlBee configuration file.
16838 @subsubheading Quassel Service
16840 @cindex IRC (Internet Relay Chat)
16841 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
16842 meaning that one or more clients can attach to and detach from the
16845 @defvr {Scheme Variable} quassel-service-type
16846 This is the service type for the @url{https://quassel-irc.org/,Quassel}
16847 IRC backend daemon. Its value is a @code{quassel-configuration}
16851 @deftp {Data Type} quassel-configuration
16852 This is the configuration for Quassel, with the following fields:
16855 @item @code{quassel} (default: @code{quassel})
16856 The Quassel package to use.
16858 @item @code{interface} (default: @code{"::,0.0.0.0"})
16859 @item @code{port} (default: @code{4242})
16860 Listen on the network interface(s) corresponding to the IPv4 or IPv6
16861 interfaces specified in the comma delimited @var{interface}, on
16864 @item @code{loglevel} (default: @code{"Info"})
16865 The level of logging desired. Accepted values are Debug, Info, Warning
16870 @node Telephony Services
16871 @subsection Telephony Services
16873 @cindex Murmur (VoIP server)
16874 @cindex VoIP server
16875 This section describes how to set up and run a Murmur server. Murmur is
16876 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
16879 @deftp {Data Type} murmur-configuration
16880 The service type for the Murmur server. An example configuration can
16884 (service murmur-service-type
16885 (murmur-configuration
16887 "Welcome to this Mumble server running on Guix!")
16888 (cert-required? #t) ;disallow text password logins
16889 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
16890 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
16893 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
16894 password with the command that is printed during the activation phase.
16896 It is recommended to register a normal Mumble user account
16897 and grant it admin or moderator rights.
16898 You can use the @code{mumble} client to
16899 login as new normal user, register yourself, and log out.
16900 For the next step login with the name @code{SuperUser} use
16901 the @code{SuperUser} password that you set previously,
16902 and grant your newly registered mumble user administrator or moderator
16903 rights and create some channels.
16905 Available @code{murmur-configuration} fields are:
16908 @item @code{package} (default: @code{mumble})
16909 Package that contains @code{bin/murmurd}.
16911 @item @code{user} (default: @code{"murmur"})
16912 User who will run the Murmur server.
16914 @item @code{group} (default: @code{"murmur"})
16915 Group of the user who will run the murmur server.
16917 @item @code{port} (default: @code{64738})
16918 Port on which the server will listen.
16920 @item @code{welcome-text} (default: @code{""})
16921 Welcome text sent to clients when they connect.
16923 @item @code{server-password} (default: @code{""})
16924 Password the clients have to enter in order to connect.
16926 @item @code{max-users} (default: @code{100})
16927 Maximum of users that can be connected to the server at once.
16929 @item @code{max-user-bandwidth} (default: @code{#f})
16930 Maximum voice traffic a user can send per second.
16932 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
16933 File name of the sqlite database.
16934 The service's user will become the owner of the directory.
16936 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
16937 File name of the log file.
16938 The service's user will become the owner of the directory.
16940 @item @code{autoban-attempts} (default: @code{10})
16941 Maximum number of logins a user can make in @code{autoban-timeframe}
16942 without getting auto banned for @code{autoban-time}.
16944 @item @code{autoban-timeframe} (default: @code{120})
16945 Timeframe for autoban in seconds.
16947 @item @code{autoban-time} (default: @code{300})
16948 Amount of time in seconds for which a client gets banned
16949 when violating the autoban limits.
16951 @item @code{opus-threshold} (default: @code{100})
16952 Percentage of clients that need to support opus
16953 before switching over to opus audio codec.
16955 @item @code{channel-nesting-limit} (default: @code{10})
16956 How deep channels can be nested at maximum.
16958 @item @code{channelname-regex} (default: @code{#f})
16959 A string in form of a Qt regular expression that channel names must conform to.
16961 @item @code{username-regex} (default: @code{#f})
16962 A string in form of a Qt regular expression that user names must conform to.
16964 @item @code{text-message-length} (default: @code{5000})
16965 Maximum size in bytes that a user can send in one text chat message.
16967 @item @code{image-message-length} (default: @code{(* 128 1024)})
16968 Maximum size in bytes that a user can send in one image message.
16970 @item @code{cert-required?} (default: @code{#f})
16971 If it is set to @code{#t} clients that use weak password authentification
16972 will not be accepted. Users must have completed the certificate wizard to join.
16974 @item @code{remember-channel?} (default: @code{#f})
16975 Should murmur remember the last channel each user was in when they disconnected
16976 and put them into the remembered channel when they rejoin.
16978 @item @code{allow-html?} (default: @code{#f})
16979 Should html be allowed in text messages, user comments, and channel descriptions.
16981 @item @code{allow-ping?} (default: @code{#f})
16982 Setting to true exposes the current user count, the maximum user count, and
16983 the server's maximum bandwidth per client to unauthenticated users. In the
16984 Mumble client, this information is shown in the Connect dialog.
16986 Disabling this setting will prevent public listing of the server.
16988 @item @code{bonjour?} (default: @code{#f})
16989 Should the server advertise itself in the local network through the bonjour protocol.
16991 @item @code{send-version?} (default: @code{#f})
16992 Should the murmur server version be exposed in ping requests.
16994 @item @code{log-days} (default: @code{31})
16995 Murmur also stores logs in the database, which are accessible via RPC.
16996 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
16997 or -1 to disable logging to the database.
16999 @item @code{obfuscate-ips?} (default: @code{#t})
17000 Should logged ips be obfuscated to protect the privacy of users.
17002 @item @code{ssl-cert} (default: @code{#f})
17003 File name of the SSL/TLS certificate used for encrypted connections.
17006 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
17008 @item @code{ssl-key} (default: @code{#f})
17009 Filepath to the ssl private key used for encrypted connections.
17011 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
17014 @item @code{ssl-dh-params} (default: @code{#f})
17015 File name of a PEM-encoded file with Diffie-Hellman parameters
17016 for the SSL/TLS encryption. Alternatively you set it to
17017 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
17018 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
17020 @item @code{ssl-ciphers} (default: @code{#f})
17021 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
17024 This option is specified using
17025 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
17026 OpenSSL cipher list notation}.
17028 It is recommended that you try your cipher string using 'openssl ciphers <string>'
17029 before setting it here, to get a feel for which cipher suites you will get.
17030 After setting this option, it is recommend that you inspect your Murmur log
17031 to ensure that Murmur is using the cipher suites that you expected it to.
17033 Note: Changing this option may impact the backwards compatibility of your
17034 Murmur server, and can remove the ability for older Mumble clients to be able
17037 @item @code{public-registration} (default: @code{#f})
17038 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
17040 You can optionally register your server in the public server list that the
17041 @code{mumble} client shows on startup.
17042 You cannot register your server if you have set a @code{server-password},
17043 or set @code{allow-ping} to @code{#f}.
17045 It might take a few hours until it shows up in the public list.
17047 @item @code{file} (default: @code{#f})
17048 Optional alternative override for this configuration.
17052 @deftp {Data Type} murmur-public-registration-configuration
17053 Configuration for public registration of a murmur service.
17057 This is a display name for your server. Not to be confused with the hostname.
17059 @item @code{password}
17060 A password to identify your registration.
17061 Subsequent updates will need the same password. Don't lose your password.
17064 This should be a @code{http://} or @code{https://} link to your web
17067 @item @code{hostname} (default: @code{#f})
17068 By default your server will be listed by its IP address.
17069 If it is set your server will be linked by this host name instead.
17075 @node Monitoring Services
17076 @subsection Monitoring Services
17078 @subsubheading Tailon Service
17080 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
17081 viewing and searching log files.
17083 The following example will configure the service with default values.
17084 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
17087 (service tailon-service-type)
17090 The following example customises more of the Tailon configuration,
17091 adding @command{sed} to the list of allowed commands.
17094 (service tailon-service-type
17095 (tailon-configuration
17097 (tailon-configuration-file
17098 (allowed-commands '("tail" "grep" "awk" "sed"))))))
17102 @deftp {Data Type} tailon-configuration
17103 Data type representing the configuration of Tailon.
17104 This type has the following parameters:
17107 @item @code{config-file} (default: @code{(tailon-configuration-file)})
17108 The configuration file to use for Tailon. This can be set to a
17109 @dfn{tailon-configuration-file} record value, or any gexp
17110 (@pxref{G-Expressions}).
17112 For example, to instead use a local file, the @code{local-file} function
17116 (service tailon-service-type
17117 (tailon-configuration
17118 (config-file (local-file "./my-tailon.conf"))))
17121 @item @code{package} (default: @code{tailon})
17122 The tailon package to use.
17127 @deftp {Data Type} tailon-configuration-file
17128 Data type representing the configuration options for Tailon.
17129 This type has the following parameters:
17132 @item @code{files} (default: @code{(list "/var/log")})
17133 List of files to display. The list can include strings for a single file
17134 or directory, or a list, where the first item is the name of a
17135 subsection, and the remaining items are the files or directories in that
17138 @item @code{bind} (default: @code{"localhost:8080"})
17139 Address and port to which Tailon should bind on.
17141 @item @code{relative-root} (default: @code{#f})
17142 URL path to use for Tailon, set to @code{#f} to not use a path.
17144 @item @code{allow-transfers?} (default: @code{#t})
17145 Allow downloading the log files in the web interface.
17147 @item @code{follow-names?} (default: @code{#t})
17148 Allow tailing of not-yet existent files.
17150 @item @code{tail-lines} (default: @code{200})
17151 Number of lines to read initially from each file.
17153 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
17154 Commands to allow running. By default, @code{sed} is disabled.
17156 @item @code{debug?} (default: @code{#f})
17157 Set @code{debug?} to @code{#t} to show debug messages.
17159 @item @code{wrap-lines} (default: @code{#t})
17160 Initial line wrapping state in the web interface. Set to @code{#t} to
17161 initially wrap lines (the default), or to @code{#f} to initially not
17164 @item @code{http-auth} (default: @code{#f})
17165 HTTP authentication type to use. Set to @code{#f} to disable
17166 authentication (the default). Supported values are @code{"digest"} or
17169 @item @code{users} (default: @code{#f})
17170 If HTTP authentication is enabled (see @code{http-auth}), access will be
17171 restricted to the credentials provided here. To configure users, use a
17172 list of pairs, where the first element of the pair is the username, and
17173 the 2nd element of the pair is the password.
17176 (tailon-configuration-file
17177 (http-auth "basic")
17178 (users '(("user1" . "password1")
17179 ("user2" . "password2"))))
17186 @subsubheading Darkstat Service
17188 Darkstat is a packet sniffer that captures network traffic, calculates
17189 statistics about usage, and serves reports over HTTP.
17191 @defvar {Scheme Variable} darkstat-service-type
17192 This is the service type for the
17193 @uref{https://unix4lyfe.org/darkstat/, darkstat}
17194 service, its value must be a @code{darkstat-configuration} record as in
17198 (service darkstat-service-type
17199 (darkstat-configuration
17200 (interface "eno1")))
17204 @deftp {Data Type} darkstat-configuration
17205 Data type representing the configuration of @command{darkstat}.
17208 @item @code{package} (default: @code{darkstat})
17209 The darkstat package to use.
17211 @item @code{interface}
17212 Capture traffic on the specified network interface.
17214 @item @code{port} (default: @code{"667"})
17215 Bind the web interface to the specified port.
17217 @item @code{bind-address} (default: @code{"127.0.0.1"})
17218 Bind the web interface to the specified address.
17220 @item @code{base} (default: @code{"/"})
17221 Specify the path of the base URL. This can be useful if
17222 @command{darkstat} is accessed via a reverse proxy.
17227 @subsubheading Prometheus Node Exporter Service
17229 @cindex prometheus-node-exporter
17230 The Prometheus ``node exporter'' makes hardware and operating system statistics
17231 provided by the Linux kernel available for the Prometheus monitoring system.
17232 This service should be deployed on all physical nodes and virtual machines,
17233 where monitoring these statistics is desirable.
17235 @defvar {Scheme variable} prometheus-node-exporter-service-type
17236 This is the service type for the
17237 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
17238 service, its value must be a @code{prometheus-node-exporter-configuration}
17239 record as in this example:
17242 (service prometheus-node-exporter-service-type
17243 (prometheus-node-exporter-configuration
17244 (web-listen-address ":9100")))
17248 @deftp {Data Type} prometheus-node-exporter-configuration
17249 Data type representing the configuration of @command{node_exporter}.
17252 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
17253 The prometheus-node-exporter package to use.
17255 @item @code{web-listen-address} (default: @code{":9100"})
17256 Bind the web interface to the specified address.
17261 @subsubheading Zabbix server
17262 @cindex zabbix zabbix-server
17263 Zabbix provides monitoring metrics, among others network utilization, CPU load
17264 and disk space consumption:
17267 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
17268 @item Auto-discovery of servers and network devices and interfaces.
17269 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
17270 @item Distributed monitoring with centralized web administration.
17271 @item Native high performance agents.
17272 @item SLA, and ITIL KPI metrics on reporting.
17273 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
17274 @item Remote command execution through Zabbix proxies.
17277 @c %start of fragment
17279 Available @code{zabbix-server-configuration} fields are:
17281 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
17282 The zabbix-server package.
17286 @deftypevr {@code{zabbix-server-configuration} parameter} string user
17287 User who will run the Zabbix server.
17289 Defaults to @samp{"zabbix"}.
17293 @deftypevr {@code{zabbix-server-configuration} parameter} group group
17294 Group who will run the Zabbix server.
17296 Defaults to @samp{"zabbix"}.
17300 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
17301 Database host name.
17303 Defaults to @samp{"127.0.0.1"}.
17307 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
17310 Defaults to @samp{"zabbix"}.
17314 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
17317 Defaults to @samp{"zabbix"}.
17321 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
17322 Database password. Please, use @code{include-files} with
17323 @code{DBPassword=SECRET} inside a specified file instead.
17325 Defaults to @samp{""}.
17329 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
17332 Defaults to @samp{5432}.
17336 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
17337 Specifies where log messages are written to:
17341 @code{system} - syslog.
17344 @code{file} - file specified with @code{log-file} parameter.
17347 @code{console} - standard output.
17351 Defaults to @samp{""}.
17355 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
17356 Log file name for @code{log-type} @code{file} parameter.
17358 Defaults to @samp{"/var/log/zabbix/server.log"}.
17362 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
17365 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
17369 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
17370 The location of certificate authority (CA) files for SSL server
17371 certificate verification.
17373 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
17377 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
17378 Location of SSL client certificates.
17380 Defaults to @samp{"/etc/ssl/certs"}.
17384 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
17385 Extra options will be appended to Zabbix server configuration file.
17387 Defaults to @samp{""}.
17391 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
17392 You may include individual files or all files in a directory in the
17393 configuration file.
17395 Defaults to @samp{()}.
17399 @c %end of fragment
17401 @subsubheading Zabbix agent
17402 @cindex zabbix zabbix-agent
17404 Zabbix agent gathers information for Zabbix server.
17406 @c %start of fragment
17408 Available @code{zabbix-agent-configuration} fields are:
17410 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
17411 The zabbix-agent package.
17415 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
17416 User who will run the Zabbix agent.
17418 Defaults to @samp{"zabbix"}.
17422 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
17423 Group who will run the Zabbix agent.
17425 Defaults to @samp{"zabbix"}.
17429 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
17430 Unique, case sensitive hostname which is required for active checks and
17431 must match hostname as configured on the server.
17433 Defaults to @samp{"Zabbix server"}.
17437 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
17438 Specifies where log messages are written to:
17442 @code{system} - syslog.
17445 @code{file} - file specified with @code{log-file} parameter.
17448 @code{console} - standard output.
17452 Defaults to @samp{""}.
17456 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
17457 Log file name for @code{log-type} @code{file} parameter.
17459 Defaults to @samp{"/var/log/zabbix/agent.log"}.
17463 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
17466 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
17470 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
17471 List of IP addresses, optionally in CIDR notation, or hostnames of
17472 Zabbix servers and Zabbix proxies. Incoming connections will be
17473 accepted only from the hosts listed here.
17475 Defaults to @samp{("127.0.0.1")}.
17479 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
17480 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
17481 proxies for active checks. If port is not specified, default port is
17482 used. If this parameter is not specified, active checks are disabled.
17484 Defaults to @samp{("127.0.0.1")}.
17488 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
17489 Extra options will be appended to Zabbix server configuration file.
17491 Defaults to @samp{""}.
17495 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
17496 You may include individual files or all files in a directory in the
17497 configuration file.
17499 Defaults to @samp{()}.
17503 @c %end of fragment
17505 @subsubheading Zabbix front-end
17506 @cindex zabbix zabbix-front-end
17508 This service provides a WEB interface to Zabbix server.
17510 @c %start of fragment
17512 Available @code{zabbix-front-end-configuration} fields are:
17514 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
17515 NGINX configuration.
17519 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
17520 Database host name.
17522 Defaults to @samp{"localhost"}.
17526 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
17529 Defaults to @samp{5432}.
17533 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
17536 Defaults to @samp{"zabbix"}.
17540 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
17543 Defaults to @samp{"zabbix"}.
17547 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
17548 Database password. Please, use @code{db-secret-file} instead.
17550 Defaults to @samp{""}.
17554 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
17555 Secret file which will be appended to @file{zabbix.conf.php} file. This
17556 file contains credentials for use by Zabbix front-end. You are expected
17557 to create it manually.
17559 Defaults to @samp{""}.
17563 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
17564 Zabbix server hostname.
17566 Defaults to @samp{"localhost"}.
17570 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
17571 Zabbix server port.
17573 Defaults to @samp{10051}.
17578 @c %end of fragment
17580 @node Kerberos Services
17581 @subsection Kerberos Services
17584 The @code{(gnu services kerberos)} module provides services relating to
17585 the authentication protocol @dfn{Kerberos}.
17587 @subsubheading Krb5 Service
17589 Programs using a Kerberos client library normally
17590 expect a configuration file in @file{/etc/krb5.conf}.
17591 This service generates such a file from a definition provided in the
17592 operating system declaration.
17593 It does not cause any daemon to be started.
17595 No ``keytab'' files are provided by this service---you must explicitly create them.
17596 This service is known to work with the MIT client library, @code{mit-krb5}.
17597 Other implementations have not been tested.
17599 @defvr {Scheme Variable} krb5-service-type
17600 A service type for Kerberos 5 clients.
17604 Here is an example of its use:
17606 (service krb5-service-type
17607 (krb5-configuration
17608 (default-realm "EXAMPLE.COM")
17609 (allow-weak-crypto? #t)
17612 (name "EXAMPLE.COM")
17613 (admin-server "groucho.example.com")
17614 (kdc "karl.example.com"))
17617 (admin-server "kerb-admin.argrx.edu")
17618 (kdc "keys.argrx.edu"))))))
17622 This example provides a Kerberos@tie{}5 client configuration which:
17624 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
17625 of which have distinct administration servers and key distribution centers;
17626 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
17627 specified by clients;
17628 @item Accepts services which only support encryption types known to be weak.
17631 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
17632 Only the most commonly used ones are described here.
17633 For a full list, and more detailed explanation of each, see the MIT
17634 @uref{http://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
17638 @deftp {Data Type} krb5-realm
17639 @cindex realm, kerberos
17642 This field is a string identifying the name of the realm.
17643 A common convention is to use the fully qualified DNS name of your organization,
17644 converted to upper case.
17646 @item @code{admin-server}
17647 This field is a string identifying the host where the administration server is
17651 This field is a string identifying the key distribution center
17656 @deftp {Data Type} krb5-configuration
17659 @item @code{allow-weak-crypto?} (default: @code{#f})
17660 If this flag is @code{#t} then services which only offer encryption algorithms
17661 known to be weak will be accepted.
17663 @item @code{default-realm} (default: @code{#f})
17664 This field should be a string identifying the default Kerberos
17665 realm for the client.
17666 You should set this field to the name of your Kerberos realm.
17667 If this value is @code{#f}
17668 then a realm must be specified with every Kerberos principal when invoking programs
17669 such as @command{kinit}.
17671 @item @code{realms}
17672 This should be a non-empty list of @code{krb5-realm} objects, which clients may
17674 Normally, one of them will have a @code{name} field matching the @code{default-realm}
17680 @subsubheading PAM krb5 Service
17683 The @code{pam-krb5} service allows for login authentication and password
17684 management via Kerberos.
17685 You will need this service if you want PAM enabled applications to authenticate
17686 users using Kerberos.
17688 @defvr {Scheme Variable} pam-krb5-service-type
17689 A service type for the Kerberos 5 PAM module.
17692 @deftp {Data Type} pam-krb5-configuration
17693 Data type representing the configuration of the Kerberos 5 PAM module
17694 This type has the following parameters:
17696 @item @code{pam-krb5} (default: @code{pam-krb5})
17697 The pam-krb5 package to use.
17699 @item @code{minimum-uid} (default: @code{1000})
17700 The smallest user ID for which Kerberos authentications should be attempted.
17701 Local accounts with lower values will silently fail to authenticate.
17706 @node LDAP Services
17707 @subsection LDAP Services
17709 @cindex nslcd, LDAP service
17711 The @code{(gnu services authentication)} module provides the
17712 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
17713 server. In addition to configuring the service itself, you may want to add
17714 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
17715 Switch} for detailed information.
17717 Here is a simple operating system declaration with a default configuration of
17718 the @code{nslcd-service-type} and a Name Service Switch configuration that
17719 consults the @code{ldap} name service last:
17722 (use-service-modules authentication)
17723 (use-modules (gnu system nss))
17729 (service nslcd-service-type)
17730 (service dhcp-client-service-type)
17732 (name-service-switch
17733 (let ((services (list (name-service (name "db"))
17734 (name-service (name "files"))
17735 (name-service (name "ldap")))))
17736 (name-service-switch
17737 (inherit %mdns-host-lookup-nss)
17738 (password services)
17741 (netgroup services)
17742 (gshadow services)))))
17745 @c %start of generated documentation for nslcd-configuration
17747 Available @code{nslcd-configuration} fields are:
17749 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
17750 The @code{nss-pam-ldapd} package to use.
17754 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
17755 The number of threads to start that can handle requests and perform LDAP
17756 queries. Each thread opens a separate connection to the LDAP server.
17757 The default is to start 5 threads.
17759 Defaults to @samp{disabled}.
17763 @deftypevr {@code{nslcd-configuration} parameter} string uid
17764 This specifies the user id with which the daemon should be run.
17766 Defaults to @samp{"nslcd"}.
17770 @deftypevr {@code{nslcd-configuration} parameter} string gid
17771 This specifies the group id with which the daemon should be run.
17773 Defaults to @samp{"nslcd"}.
17777 @deftypevr {@code{nslcd-configuration} parameter} log-option log
17778 This option controls the way logging is done via a list containing
17779 SCHEME and LEVEL. The SCHEME argument may either be the symbols "none"
17780 or "syslog", or an absolute file name. The LEVEL argument is optional
17781 and specifies the log level. The log level may be one of the following
17782 symbols: "crit", "error", "warning", "notice", "info" or "debug". All
17783 messages with the specified log level or higher are logged.
17785 Defaults to @samp{("/var/log/nslcd" info)}.
17789 @deftypevr {@code{nslcd-configuration} parameter} list uri
17790 The list of LDAP server URIs. Normally, only the first server will be
17791 used with the following servers as fall-back.
17793 Defaults to @samp{("ldap://localhost:389/")}.
17797 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
17798 The version of the LDAP protocol to use. The default is to use the
17799 maximum version supported by the LDAP library.
17801 Defaults to @samp{disabled}.
17805 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
17806 Specifies the distinguished name with which to bind to the directory
17807 server for lookups. The default is to bind anonymously.
17809 Defaults to @samp{disabled}.
17813 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
17814 Specifies the credentials with which to bind. This option is only
17815 applicable when used with binddn.
17817 Defaults to @samp{disabled}.
17821 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
17822 Specifies the distinguished name to use when the root user tries to
17823 modify a user's password using the PAM module.
17825 Defaults to @samp{disabled}.
17829 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
17830 Specifies the credentials with which to bind if the root user tries to
17831 change a user's password. This option is only applicable when used with
17834 Defaults to @samp{disabled}.
17838 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
17839 Specifies the SASL mechanism to be used when performing SASL
17842 Defaults to @samp{disabled}.
17846 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
17847 Specifies the SASL realm to be used when performing SASL authentication.
17849 Defaults to @samp{disabled}.
17853 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
17854 Specifies the authentication identity to be used when performing SASL
17857 Defaults to @samp{disabled}.
17861 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
17862 Specifies the authorization identity to be used when performing SASL
17865 Defaults to @samp{disabled}.
17869 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
17870 Determines whether the LDAP server host name should be canonicalised. If
17871 this is enabled the LDAP library will do a reverse host name lookup. By
17872 default, it is left up to the LDAP library whether this check is
17875 Defaults to @samp{disabled}.
17879 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
17880 Set the name for the GSS-API Kerberos credentials cache.
17882 Defaults to @samp{disabled}.
17886 @deftypevr {@code{nslcd-configuration} parameter} string base
17887 The directory search base.
17889 Defaults to @samp{"dc=example,dc=com"}.
17893 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
17894 Specifies the search scope (subtree, onelevel, base or children). The
17895 default scope is subtree; base scope is almost never useful for name
17896 service lookups; children scope is not supported on all servers.
17898 Defaults to @samp{(subtree)}.
17902 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
17903 Specifies the policy for dereferencing aliases. The default policy is
17904 to never dereference aliases.
17906 Defaults to @samp{disabled}.
17910 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
17911 Specifies whether automatic referral chasing should be enabled. The
17912 default behaviour is to chase referrals.
17914 Defaults to @samp{disabled}.
17918 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
17919 This option allows for custom attributes to be looked up instead of the
17920 default RFC 2307 attributes. It is a list of maps, each consisting of
17921 the name of a map, the RFC 2307 attribute to match and the query
17922 expression for the attribute as it is available in the directory.
17924 Defaults to @samp{()}.
17928 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
17929 A list of filters consisting of the name of a map to which the filter
17930 applies and an LDAP search filter expression.
17932 Defaults to @samp{()}.
17936 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
17937 Specifies the time limit in seconds to use when connecting to the
17938 directory server. The default value is 10 seconds.
17940 Defaults to @samp{disabled}.
17944 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
17945 Specifies the time limit (in seconds) to wait for a response from the
17946 LDAP server. A value of zero, which is the default, is to wait
17947 indefinitely for searches to be completed.
17949 Defaults to @samp{disabled}.
17953 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
17954 Specifies the period if inactivity (in seconds) after which the con‐
17955 nection to the LDAP server will be closed. The default is not to time
17958 Defaults to @samp{disabled}.
17962 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
17963 Specifies the number of seconds to sleep when connecting to all LDAP
17964 servers fails. By default one second is waited between the first
17965 failure and the first retry.
17967 Defaults to @samp{disabled}.
17971 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
17972 Specifies the time after which the LDAP server is considered to be
17973 permanently unavailable. Once this time is reached retries will be done
17974 only once per this time period. The default value is 10 seconds.
17976 Defaults to @samp{disabled}.
17980 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
17981 Specifies whether to use SSL/TLS or not (the default is not to). If
17982 'start-tls is specified then StartTLS is used rather than raw LDAP over
17985 Defaults to @samp{disabled}.
17989 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
17990 Specifies what checks to perform on a server-supplied certificate. The
17991 meaning of the values is described in the ldap.conf(5) manual page.
17993 Defaults to @samp{disabled}.
17997 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
17998 Specifies the directory containing X.509 certificates for peer authen‐
17999 tication. This parameter is ignored when using GnuTLS.
18001 Defaults to @samp{disabled}.
18005 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
18006 Specifies the path to the X.509 certificate for peer authentication.
18008 Defaults to @samp{disabled}.
18012 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
18013 Specifies the path to an entropy source. This parameter is ignored when
18016 Defaults to @samp{disabled}.
18020 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
18021 Specifies the ciphers to use for TLS as a string.
18023 Defaults to @samp{disabled}.
18027 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
18028 Specifies the path to the file containing the local certificate for
18029 client TLS authentication.
18031 Defaults to @samp{disabled}.
18035 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
18036 Specifies the path to the file containing the private key for client TLS
18039 Defaults to @samp{disabled}.
18043 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
18044 Set this to a number greater than 0 to request paged results from the
18045 LDAP server in accordance with RFC2696. The default (0) is to not
18046 request paged results.
18048 Defaults to @samp{disabled}.
18052 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
18053 This option prevents group membership lookups through LDAP for the
18054 specified users. Alternatively, the value 'all-local may be used. With
18055 that value nslcd builds a full list of non-LDAP users on startup.
18057 Defaults to @samp{disabled}.
18061 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
18062 This option ensures that LDAP users with a numeric user id lower than
18063 the specified value are ignored.
18065 Defaults to @samp{disabled}.
18069 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
18070 This option specifies an offset that is added to all LDAP numeric user
18071 ids. This can be used to avoid user id collisions with local users.
18073 Defaults to @samp{disabled}.
18077 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
18078 This option specifies an offset that is added to all LDAP numeric group
18079 ids. This can be used to avoid user id collisions with local groups.
18081 Defaults to @samp{disabled}.
18085 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
18086 If this option is set, the member attribute of a group may point to
18087 another group. Members of nested groups are also returned in the higher
18088 level group and parent groups are returned when finding groups for a
18089 specific user. The default is not to perform extra searches for nested
18092 Defaults to @samp{disabled}.
18096 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
18097 If this option is set, the group member list is not retrieved when
18098 looking up groups. Lookups for finding which groups a user belongs to
18099 will remain functional so the user will likely still get the correct
18100 groups assigned on login.
18102 Defaults to @samp{disabled}.
18106 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
18107 If this option is set, functions which cause all user/group entries to
18108 be loaded from the directory will not succeed in doing so. This can
18109 dramatically reduce LDAP server load in situations where there are a
18110 great number of users and/or groups. This option is not recommended for
18111 most configurations.
18113 Defaults to @samp{disabled}.
18117 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
18118 This option can be used to specify how user and group names are verified
18119 within the system. This pattern is used to check all user and group
18120 names that are requested and returned from LDAP.
18122 Defaults to @samp{disabled}.
18126 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
18127 This specifies whether or not to perform searches using case-insensitive
18128 matching. Enabling this could open up the system to authorization
18129 bypass vulnerabilities and introduce nscd cache poisoning
18130 vulnerabilities which allow denial of service.
18132 Defaults to @samp{disabled}.
18136 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
18137 This option specifies whether password policy controls are requested and
18138 handled from the LDAP server when performing user authentication.
18140 Defaults to @samp{disabled}.
18144 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
18145 By default nslcd performs an LDAP search with the user's credentials
18146 after BIND (authentication) to ensure that the BIND operation was
18147 successful. The default search is a simple check to see if the user's
18148 DN exists. A search filter can be specified that will be used instead.
18149 It should return at least one entry.
18151 Defaults to @samp{disabled}.
18155 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
18156 This option allows flexible fine tuning of the authorisation check that
18157 should be performed. The search filter specified is executed and if any
18158 entries match, access is granted, otherwise access is denied.
18160 Defaults to @samp{disabled}.
18164 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
18165 If this option is set password modification using pam_ldap will be
18166 denied and the specified message will be presented to the user instead.
18167 The message can be used to direct the user to an alternative means of
18168 changing their password.
18170 Defaults to @samp{disabled}.
18174 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
18175 List of pam service names for which LDAP authentication should suffice.
18177 Defaults to @samp{()}.
18181 @c %end of generated documentation for nslcd-configuration
18185 @subsection Web Services
18190 The @code{(gnu services web)} module provides the Apache HTTP Server,
18191 the nginx web server, and also a fastcgi wrapper daemon.
18193 @subsubheading Apache HTTP Server
18195 @deffn {Scheme Variable} httpd-service-type
18196 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
18197 (@dfn{httpd}). The value for this service type is a
18198 @code{httpd-configuration} record.
18200 A simple example configuration is given below.
18203 (service httpd-service-type
18204 (httpd-configuration
18207 (server-name "www.example.com")
18208 (document-root "/srv/http/www.example.com")))))
18211 Other services can also extend the @code{httpd-service-type} to add to
18215 (simple-service 'my-extra-server httpd-service-type
18219 (list (string-append
18220 "ServerName "www.example.com
18221 DocumentRoot \"/srv/http/www.example.com\"")))))
18225 The details for the @code{httpd-configuration}, @code{httpd-module},
18226 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
18229 @deffn {Data Type} httpd-configuration
18230 This data type represents the configuration for the httpd service.
18233 @item @code{package} (default: @code{httpd})
18234 The httpd package to use.
18236 @item @code{pid-file} (default: @code{"/var/run/httpd"})
18237 The pid file used by the shepherd-service.
18239 @item @code{config} (default: @code{(httpd-config-file)})
18240 The configuration file to use with the httpd service. The default value
18241 is a @code{httpd-config-file} record, but this can also be a different
18242 G-expression that generates a file, for example a @code{plain-file}. A
18243 file outside of the store can also be specified through a string.
18248 @deffn {Data Type} httpd-module
18249 This data type represents a module for the httpd service.
18253 The name of the module.
18256 The file for the module. This can be relative to the httpd package being
18257 used, the absolute location of a file, or a G-expression for a file
18258 within the store, for example @code{(file-append mod-wsgi
18259 "/modules/mod_wsgi.so")}.
18264 @defvr {Scheme Variable} %default-httpd-modules
18265 A default list of @code{httpd-module} objects.
18268 @deffn {Data Type} httpd-config-file
18269 This data type represents a configuration file for the httpd service.
18272 @item @code{modules} (default: @code{%default-httpd-modules})
18273 The modules to load. Additional modules can be added here, or loaded by
18274 additional configuration.
18276 For example, in order to handle requests for PHP files, you can use Apache’s
18277 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
18280 (service httpd-service-type
18281 (httpd-configuration
18286 (name "proxy_module")
18287 (file "modules/mod_proxy.so"))
18289 (name "proxy_fcgi_module")
18290 (file "modules/mod_proxy_fcgi.so"))
18291 %default-httpd-modules))
18292 (extra-config (list "\
18293 <FilesMatch \\.php$>
18294 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
18295 </FilesMatch>"))))))
18296 (service php-fpm-service-type
18297 (php-fpm-configuration
18298 (socket "/var/run/php-fpm.sock")
18299 (socket-group "httpd")))
18302 @item @code{server-root} (default: @code{httpd})
18303 The @code{ServerRoot} in the configuration file, defaults to the httpd
18304 package. Directives including @code{Include} and @code{LoadModule} are
18305 taken as relative to the server root.
18307 @item @code{server-name} (default: @code{#f})
18308 The @code{ServerName} in the configuration file, used to specify the
18309 request scheme, hostname and port that the server uses to identify
18312 This doesn't need to be set in the server config, and can be specifyed
18313 in virtual hosts. The default is @code{#f} to not specify a
18316 @item @code{document-root} (default: @code{"/srv/http"})
18317 The @code{DocumentRoot} from which files will be served.
18319 @item @code{listen} (default: @code{'("80")})
18320 The list of values for the @code{Listen} directives in the config
18321 file. The value should be a list of strings, when each string can
18322 specify the port number to listen on, and optionally the IP address and
18325 @item @code{pid-file} (default: @code{"/var/run/httpd"})
18326 The @code{PidFile} to use. This should match the @code{pid-file} set in
18327 the @code{httpd-configuration} so that the Shepherd service is
18328 configured correctly.
18330 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
18331 The @code{ErrorLog} to which the server will log errors.
18333 @item @code{user} (default: @code{"httpd"})
18334 The @code{User} which the server will answer requests as.
18336 @item @code{group} (default: @code{"httpd"})
18337 The @code{Group} which the server will answer requests as.
18339 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
18340 A flat list of strings and G-expressions which will be added to the end
18341 of the configuration file.
18343 Any values which the service is extended with will be appended to this
18349 @deffn {Data Type} httpd-virtualhost
18350 This data type represents a virtualhost configuration block for the httpd service.
18352 These should be added to the extra-config for the httpd-service.
18355 (simple-service 'my-extra-server httpd-service-type
18359 (list (string-append
18360 "ServerName "www.example.com
18361 DocumentRoot \"/srv/http/www.example.com\"")))))
18365 @item @code{addresses-and-ports}
18366 The addresses and ports for the @code{VirtualHost} directive.
18368 @item @code{contents}
18369 The contents of the @code{VirtualHost} directive, this should be a list
18370 of strings and G-expressions.
18375 @subsubheading NGINX
18377 @deffn {Scheme Variable} nginx-service-type
18378 Service type for the @uref{https://nginx.org/,NGinx} web server. The
18379 value for this service type is a @code{<nginx-configuration>} record.
18381 A simple example configuration is given below.
18384 (service nginx-service-type
18385 (nginx-configuration
18387 (list (nginx-server-configuration
18388 (server-name '("www.example.com"))
18389 (root "/srv/http/www.example.com"))))))
18392 In addition to adding server blocks to the service configuration
18393 directly, this service can be extended by other services to add server
18394 blocks, as in this example:
18397 (simple-service 'my-extra-server nginx-service-type
18398 (list (nginx-server-configuration
18399 (root "/srv/http/extra-website")
18400 (try-files (list "$uri" "$uri/index.html")))))
18404 At startup, @command{nginx} has not yet read its configuration file, so
18405 it uses a default file to log error messages. If it fails to load its
18406 configuration file, that is where error messages are logged. After the
18407 configuration file is loaded, the default error log file changes as per
18408 configuration. In our case, startup error messages can be found in
18409 @file{/var/run/nginx/logs/error.log}, and after configuration in
18410 @file{/var/log/nginx/error.log}. The second location can be changed
18411 with the @var{log-directory} configuration option.
18413 @deffn {Data Type} nginx-configuration
18414 This data type represents the configuration for NGinx. Some
18415 configuration can be done through this and the other provided record
18416 types, or alternatively, a config file can be provided.
18419 @item @code{nginx} (default: @code{nginx})
18420 The nginx package to use.
18422 @item @code{log-directory} (default: @code{"/var/log/nginx"})
18423 The directory to which NGinx will write log files.
18425 @item @code{run-directory} (default: @code{"/var/run/nginx"})
18426 The directory in which NGinx will create a pid file, and write temporary
18429 @item @code{server-blocks} (default: @code{'()})
18430 A list of @dfn{server blocks} to create in the generated configuration
18431 file, the elements should be of type
18432 @code{<nginx-server-configuration>}.
18434 The following example would setup NGinx to serve @code{www.example.com}
18435 from the @code{/srv/http/www.example.com} directory, without using
18438 (service nginx-service-type
18439 (nginx-configuration
18441 (list (nginx-server-configuration
18442 (server-name '("www.example.com"))
18443 (root "/srv/http/www.example.com"))))))
18446 @item @code{upstream-blocks} (default: @code{'()})
18447 A list of @dfn{upstream blocks} to create in the generated configuration
18448 file, the elements should be of type
18449 @code{<nginx-upstream-configuration>}.
18451 Configuring upstreams through the @code{upstream-blocks} can be useful
18452 when combined with @code{locations} in the
18453 @code{<nginx-server-configuration>} records. The following example
18454 creates a server configuration with one location configuration, that
18455 will proxy requests to a upstream configuration, which will handle
18456 requests with two servers.
18461 (nginx-configuration
18463 (list (nginx-server-configuration
18464 (server-name '("www.example.com"))
18465 (root "/srv/http/www.example.com")
18468 (nginx-location-configuration
18470 (body '("proxy_pass http://server-proxy;"))))))))
18472 (list (nginx-upstream-configuration
18473 (name "server-proxy")
18474 (servers (list "server1.example.com"
18475 "server2.example.com")))))))
18478 @item @code{file} (default: @code{#f})
18479 If a configuration @var{file} is provided, this will be used, rather than
18480 generating a configuration file from the provided @code{log-directory},
18481 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
18482 proper operation, these arguments should match what is in @var{file} to ensure
18483 that the directories are created when the service is activated.
18485 This can be useful if you have an existing configuration file, or it's
18486 not possible to do what is required through the other parts of the
18487 nginx-configuration record.
18489 @item @code{server-names-hash-bucket-size} (default: @code{#f})
18490 Bucket size for the server names hash tables, defaults to @code{#f} to
18491 use the size of the processors cache line.
18493 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
18494 Maximum bucket size for the server names hash tables.
18496 @item @code{extra-content} (default: @code{""})
18497 Extra content for the @code{http} block. Should be string or a string
18498 valued G-expression.
18503 @deftp {Data Type} nginx-server-configuration
18504 Data type representing the configuration of an nginx server block.
18505 This type has the following parameters:
18508 @item @code{listen} (default: @code{'("80" "443 ssl")})
18509 Each @code{listen} directive sets the address and port for IP, or the
18510 path for a UNIX-domain socket on which the server will accept requests.
18511 Both address and port, or only address or only port can be specified.
18512 An address may also be a hostname, for example:
18515 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
18518 @item @code{server-name} (default: @code{(list 'default)})
18519 A list of server names this server represents. @code{'default} represents the
18520 default server for connections matching no other server.
18522 @item @code{root} (default: @code{"/srv/http"})
18523 Root of the website nginx will serve.
18525 @item @code{locations} (default: @code{'()})
18526 A list of @dfn{nginx-location-configuration} or
18527 @dfn{nginx-named-location-configuration} records to use within this
18530 @item @code{index} (default: @code{(list "index.html")})
18531 Index files to look for when clients ask for a directory. If it cannot be found,
18532 Nginx will send the list of files in the directory.
18534 @item @code{try-files} (default: @code{'()})
18535 A list of files whose existence is checked in the specified order.
18536 @code{nginx} will use the first file it finds to process the request.
18538 @item @code{ssl-certificate} (default: @code{#f})
18539 Where to find the certificate for secure connections. Set it to @code{#f} if
18540 you don't have a certificate or you don't want to use HTTPS.
18542 @item @code{ssl-certificate-key} (default: @code{#f})
18543 Where to find the private key for secure connections. Set it to @code{#f} if
18544 you don't have a key or you don't want to use HTTPS.
18546 @item @code{server-tokens?} (default: @code{#f})
18547 Whether the server should add its configuration to response.
18549 @item @code{raw-content} (default: @code{'()})
18550 A list of raw lines added to the server block.
18555 @deftp {Data Type} nginx-upstream-configuration
18556 Data type representing the configuration of an nginx @code{upstream}
18557 block. This type has the following parameters:
18561 Name for this group of servers.
18563 @item @code{servers}
18564 Specify the addresses of the servers in the group. The address can be
18565 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
18566 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
18567 prefix @samp{unix:}. For addresses using an IP address or domain name,
18568 the default port is 80, and a different port can be specified
18574 @deftp {Data Type} nginx-location-configuration
18575 Data type representing the configuration of an nginx @code{location}
18576 block. This type has the following parameters:
18580 URI which this location block matches.
18582 @anchor{nginx-location-configuration body}
18584 Body of the location block, specified as a list of strings. This can contain
18586 configuration directives. For example, to pass requests to a upstream
18587 server group defined using an @code{nginx-upstream-configuration} block,
18588 the following directive would be specified in the body @samp{(list "proxy_pass
18589 http://upstream-name;")}.
18594 @deftp {Data Type} nginx-named-location-configuration
18595 Data type representing the configuration of an nginx named location
18596 block. Named location blocks are used for request redirection, and not
18597 used for regular request processing. This type has the following
18602 Name to identify this location block.
18605 @xref{nginx-location-configuration body}, as the body for named location
18606 blocks can be used in a similar way to the
18607 @code{nginx-location-configuration body}. One restriction is that the
18608 body of a named location block cannot contain location blocks.
18613 @subsubheading Varnish Cache
18615 Varnish is a fast cache server that sits in between web applications
18616 and end users. It proxies requests from clients and caches the
18617 accessed URLs such that multiple requests for the same resource only
18618 creates one request to the back-end.
18620 @defvr {Scheme Variable} varnish-service-type
18621 Service type for the Varnish daemon.
18624 @deftp {Data Type} varnish-configuration
18625 Data type representing the @code{varnish} service configuration.
18626 This type has the following parameters:
18629 @item @code{package} (default: @code{varnish})
18630 The Varnish package to use.
18632 @item @code{name} (default: @code{"default"})
18633 A name for this Varnish instance. Varnish will create a directory in
18634 @file{/var/varnish/} with this name and keep temporary files there. If
18635 the name starts with a forward slash, it is interpreted as an absolute
18638 Pass the @code{-n} argument to other Varnish programs to connect to the
18639 named instance, e.g.@: @command{varnishncsa -n default}.
18641 @item @code{backend} (default: @code{"localhost:8080"})
18642 The backend to use. This option has no effect if @code{vcl} is set.
18644 @item @code{vcl} (default: #f)
18645 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
18646 is @code{#f}, Varnish will proxy @code{backend} using the default
18647 configuration. Otherwise this must be a file-like object with valid
18650 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
18651 For example, to mirror @url{http://www.gnu.org,www.gnu.org} with VCL you
18652 can do something along these lines:
18655 (define %gnu-mirror
18659 backend gnu @{ .host = "www.gnu.org"; @}"))
18663 (services (cons (service varnish-service-type
18664 (varnish-configuration
18666 (vcl %gnu-mirror)))
18670 The configuration of an already running Varnish instance can be inspected
18671 and changed using the @command{varnishadm} program.
18673 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
18674 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
18675 comprehensive documentation on Varnish and its configuration language.
18677 @item @code{listen} (default: @code{'("localhost:80")})
18678 List of addresses Varnish will listen on.
18680 @item @code{storage} (default: @code{'("malloc,128m")})
18681 List of storage backends that will be available in VCL.
18683 @item @code{parameters} (default: @code{'()})
18684 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
18686 @item @code{extra-options} (default: @code{'()})
18687 Additional arguments to pass to the @command{varnishd} process.
18692 @subsubheading FastCGI
18695 FastCGI is an interface between the front-end and the back-end of a web
18696 service. It is a somewhat legacy facility; new web services should
18697 generally just talk HTTP between the front-end and the back-end.
18698 However there are a number of back-end services such as PHP or the
18699 optimized HTTP Git repository access that use FastCGI, so we have
18700 support for it in Guix.
18702 To use FastCGI, you configure the front-end web server (e.g., nginx) to
18703 dispatch some subset of its requests to the fastcgi backend, which
18704 listens on a local TCP or UNIX socket. There is an intermediary
18705 @code{fcgiwrap} program that sits between the actual backend process and
18706 the web server. The front-end indicates which backend program to run,
18707 passing that information to the @code{fcgiwrap} process.
18709 @defvr {Scheme Variable} fcgiwrap-service-type
18710 A service type for the @code{fcgiwrap} FastCGI proxy.
18713 @deftp {Data Type} fcgiwrap-configuration
18714 Data type representing the configuration of the @code{fcgiwrap} service.
18715 This type has the following parameters:
18717 @item @code{package} (default: @code{fcgiwrap})
18718 The fcgiwrap package to use.
18720 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
18721 The socket on which the @code{fcgiwrap} process should listen, as a
18722 string. Valid @var{socket} values include
18723 @code{unix:@var{/path/to/unix/socket}},
18724 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
18725 @code{tcp6:[@var{ipv6_addr}]:port}.
18727 @item @code{user} (default: @code{fcgiwrap})
18728 @itemx @code{group} (default: @code{fcgiwrap})
18729 The user and group names, as strings, under which to run the
18730 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
18731 the user asks for the specific user or group names @code{fcgiwrap} that
18732 the corresponding user and/or group is present on the system.
18734 It is possible to configure a FastCGI-backed web service to pass HTTP
18735 authentication information from the front-end to the back-end, and to
18736 allow @code{fcgiwrap} to run the back-end process as a corresponding
18737 local user. To enable this capability on the back-end., run
18738 @code{fcgiwrap} as the @code{root} user and group. Note that this
18739 capability also has to be configured on the front-end as well.
18744 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
18745 with some additional features useful for sites of any size.
18747 These features include:
18749 @item Adaptive process spawning
18750 @item Basic statistics (similar to Apache's mod_status)
18751 @item Advanced process management with graceful stop/start
18752 @item Ability to start workers with different uid/gid/chroot/environment
18753 and different php.ini (replaces safe_mode)
18754 @item Stdout & stderr logging
18755 @item Emergency restart in case of accidental opcode cache destruction
18756 @item Accelerated upload support
18757 @item Support for a "slowlog"
18758 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
18759 a special function to finish request & flush all data while continuing to do
18760 something time-consuming (video converting, stats processing, etc.)
18762 ...@: and much more.
18764 @defvr {Scheme Variable} php-fpm-service-type
18765 A Service type for @code{php-fpm}.
18768 @deftp {Data Type} php-fpm-configuration
18769 Data Type for php-fpm service configuration.
18771 @item @code{php} (default: @code{php})
18772 The php package to use.
18773 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
18774 The address on which to accept FastCGI requests. Valid syntaxes are:
18776 @item @code{"ip.add.re.ss:port"}
18777 Listen on a TCP socket to a specific address on a specific port.
18778 @item @code{"port"}
18779 Listen on a TCP socket to all addresses on a specific port.
18780 @item @code{"/path/to/unix/socket"}
18781 Listen on a unix socket.
18784 @item @code{user} (default: @code{php-fpm})
18785 User who will own the php worker processes.
18786 @item @code{group} (default: @code{php-fpm})
18787 Group of the worker processes.
18788 @item @code{socket-user} (default: @code{php-fpm})
18789 User who can speak to the php-fpm socket.
18790 @item @code{socket-group} (default: @code{php-fpm})
18791 Group that can speak to the php-fpm socket.
18792 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
18793 The process id of the php-fpm process is written to this file
18794 once the service has started.
18795 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
18796 Log for the php-fpm master process.
18797 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
18798 Detailed settings for the php-fpm process manager.
18801 @item @code{<php-fpm-dynamic-process-manager-configuration>}
18802 @item @code{<php-fpm-static-process-manager-configuration>}
18803 @item @code{<php-fpm-on-demand-process-manager-configuration>}
18805 @item @code{display-errors} (default @code{#f})
18806 Determines whether php errors and warning should be sent to clients
18807 and displayed in their browsers.
18808 This is useful for local php development, but a security risk for public sites,
18809 as error messages can reveal passwords and personal data.
18810 @item @code{timezone} (default @code{#f})
18811 Specifies @code{php_admin_value[date.timezone]} parameter.
18812 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
18813 This file will log the @code{stderr} outputs of php worker processes.
18814 Can be set to @code{#f} to disable logging.
18815 @item @code{file} (default @code{#f})
18816 An optional override of the whole configuration.
18817 You can use the @code{mixed-text-file} function or an absolute filepath for it.
18821 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
18822 Data Type for the @code{dynamic} php-fpm process manager. With the
18823 @code{dynamic} process manager, spare worker processes are kept around
18824 based on it's configured limits.
18826 @item @code{max-children} (default: @code{5})
18827 Maximum of worker processes.
18828 @item @code{start-servers} (default: @code{2})
18829 How many worker processes should be started on start-up.
18830 @item @code{min-spare-servers} (default: @code{1})
18831 How many spare worker processes should be kept around at minimum.
18832 @item @code{max-spare-servers} (default: @code{3})
18833 How many spare worker processes should be kept around at maximum.
18837 @deftp {Data type} php-fpm-static-process-manager-configuration
18838 Data Type for the @code{static} php-fpm process manager. With the
18839 @code{static} process manager, an unchanging number of worker processes
18842 @item @code{max-children} (default: @code{5})
18843 Maximum of worker processes.
18847 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
18848 Data Type for the @code{on-demand} php-fpm process manager. With the
18849 @code{on-demand} process manager, worker processes are only created as
18852 @item @code{max-children} (default: @code{5})
18853 Maximum of worker processes.
18854 @item @code{process-idle-timeout} (default: @code{10})
18855 The time in seconds after which a process with no requests is killed.
18860 @deffn {Scheme Procedure} nginx-php-fpm-location @
18861 [#:nginx-package nginx] @
18862 [socket (string-append "/var/run/php" @
18863 (version-major (package-version php)) @
18865 A helper function to quickly add php to an @code{nginx-server-configuration}.
18868 A simple services setup for nginx with php can look like this:
18870 (services (cons* (service dhcp-client-service-type)
18871 (service php-fpm-service-type)
18872 (service nginx-service-type
18873 (nginx-server-configuration
18874 (server-name '("example.com"))
18875 (root "/srv/http/")
18877 (list (nginx-php-location)))
18879 (ssl-certificate #f)
18880 (ssl-certificate-key #f)))
18884 @cindex cat-avatar-generator
18885 The cat avatar generator is a simple service to demonstrate the use of php-fpm
18886 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
18887 the hash of a user's email address.
18889 @deffn {Scheme Procedure} cat-avatar-generator-service @
18890 [#:cache-dir "/var/cache/cat-avatar-generator"] @
18891 [#:package cat-avatar-generator] @
18892 [#:configuration (nginx-server-configuration)]
18893 Returns an nginx-server-configuration that inherits @code{configuration}. It
18894 extends the nginx configuration to add a server block that serves @code{package},
18895 a version of cat-avatar-generator. During execution, cat-avatar-generator will
18896 be able to use @code{cache-dir} as its cache directory.
18899 A simple setup for cat-avatar-generator can look like this:
18901 (services (cons* (cat-avatar-generator-service
18903 (nginx-server-configuration
18904 (server-name '("example.com"))))
18909 @subsubheading Hpcguix-web
18911 @cindex hpcguix-web
18912 The @uref{hpcguix-web, https://github.com/UMCUGenetics/hpcguix-web/}
18913 program is a customizable web interface to browse Guix packages,
18914 initially designed for users of high-performance computing (HPC)
18917 @defvr {Scheme Variable} hpcguix-web-service-type
18918 The service type for @code{hpcguix-web}.
18921 @deftp {Data Type} hpcguix-web-configuration
18922 Data type for the hpcguix-web service configuration.
18926 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
18927 configuration. The main items available in this spec are:
18930 @item @code{title-prefix} (default: @code{"hpcguix | "})
18931 The page title prefix.
18933 @item @code{guix-command} (default: @code{"guix"})
18934 The @command{guix} command.
18936 @item @code{package-filter-proc} (default: @code{(const #t)})
18937 A procedure specifying how to filter packages that are displayed.
18939 @item @code{package-page-extension-proc} (default: @code{(const '())})
18940 Extension package for @code{hpcguix-web}.
18942 @item @code{menu} (default: @code{'()})
18943 Additional entry in page @code{menu}.
18945 @item @code{channels} (default: @code{%default-channels})
18946 List of channels from which the package list is built (@pxref{Channels}).
18948 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
18949 The expiration time, in seconds, after which the package list is rebuilt from
18950 the latest instances of the given channels.
18953 See the hpcguix-web repository for a
18954 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
18957 @item @code{package} (default: @code{hpcguix-web})
18958 The hpcguix-web package to use.
18962 A typical hpcguix-web service declaration looks like this:
18965 (service hpcguix-web-service-type
18966 (hpcguix-web-configuration
18968 #~(define site-config
18969 (hpcweb-configuration
18970 (title-prefix "Guix-HPC - ")
18971 (menu '(("/about" "ABOUT"))))))))
18975 The hpcguix-web service periodically updates the package list it publishes by
18976 pulling channels from Git. To that end, it needs to access X.509 certificates
18977 so that it can authenticate Git servers when communicating over HTTPS, and it
18978 assumes that @file{/etc/ssl/certs} contains those certificates.
18980 Thus, make sure to add @code{nss-certs} or another certificate package to the
18981 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
18982 more information on X.509 certificates.
18985 @node Certificate Services
18986 @subsection Certificate Services
18989 @cindex HTTP, HTTPS
18990 @cindex Let's Encrypt
18991 @cindex TLS certificates
18992 The @code{(gnu services certbot)} module provides a service to
18993 automatically obtain a valid TLS certificate from the Let's Encrypt
18994 certificate authority. These certificates can then be used to serve
18995 content securely over HTTPS or other TLS-based protocols, with the
18996 knowledge that the client will be able to verify the server's
18999 @url{https://letsencrypt.org/, Let's Encrypt} provides the
19000 @code{certbot} tool to automate the certification process. This tool
19001 first securely generates a key on the server. It then makes a request
19002 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
19003 checks that the request originates from the host in question by using a
19004 challenge-response protocol, requiring the server to provide its
19005 response over HTTP. If that protocol completes successfully, the CA
19006 signs the key, resulting in a certificate. That certificate is valid
19007 for a limited period of time, and therefore to continue to provide TLS
19008 services, the server needs to periodically ask the CA to renew its
19011 The certbot service automates this process: the initial key
19012 generation, the initial certification request to the Let's Encrypt
19013 service, the web server challenge/response integration, writing the
19014 certificate to disk, the automated periodic renewals, and the deployment
19015 tasks associated with the renewal (e.g.@: reloading services, copying keys
19016 with different permissions).
19018 Certbot is run twice a day, at a random minute within the hour. It
19019 won't do anything until your certificates are due for renewal or
19020 revoked, but running it regularly would give your service a chance of
19021 staying online in case a Let's Encrypt-initiated revocation happened for
19024 By using this service, you agree to the ACME Subscriber Agreement, which
19025 can be found there:
19026 @url{https://acme-v01.api.letsencrypt.org/directory}.
19028 @defvr {Scheme Variable} certbot-service-type
19029 A service type for the @code{certbot} Let's Encrypt client. Its value
19030 must be a @code{certbot-configuration} record as in this example:
19033 (define %nginx-deploy-hook
19035 "nginx-deploy-hook"
19036 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
19037 (kill pid SIGHUP))))
19039 (service certbot-service-type
19040 (certbot-configuration
19041 (email "foo@@example.net")
19044 (certificate-configuration
19045 (domains '("example.net" "www.example.net"))
19046 (deploy-hook %nginx-deploy-hook))
19047 (certificate-configuration
19048 (domains '("bar.example.net")))))))
19051 See below for details about @code{certbot-configuration}.
19054 @deftp {Data Type} certbot-configuration
19055 Data type representing the configuration of the @code{certbot} service.
19056 This type has the following parameters:
19059 @item @code{package} (default: @code{certbot})
19060 The certbot package to use.
19062 @item @code{webroot} (default: @code{/var/www})
19063 The directory from which to serve the Let's Encrypt challenge/response
19066 @item @code{certificates} (default: @code{()})
19067 A list of @code{certificates-configuration}s for which to generate
19068 certificates and request signatures. Each certificate has a @code{name}
19069 and several @code{domains}.
19072 Mandatory email used for registration, recovery contact, and important
19073 account notifications.
19075 @item @code{rsa-key-size} (default: @code{2048})
19076 Size of the RSA key.
19078 @item @code{default-location} (default: @i{see below})
19079 The default @code{nginx-location-configuration}. Because @code{certbot}
19080 needs to be able to serve challenges and responses, it needs to be able
19081 to run a web server. It does so by extending the @code{nginx} web
19082 service with an @code{nginx-server-configuration} listening on the
19083 @var{domains} on port 80, and which has a
19084 @code{nginx-location-configuration} for the @code{/.well-known/} URI
19085 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
19086 these nginx configuration data types.
19088 Requests to other URL paths will be matched by the
19089 @code{default-location}, which if present is added to all
19090 @code{nginx-server-configuration}s.
19092 By default, the @code{default-location} will issue a redirect from
19093 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
19094 you to define what to serve on your site via @code{https}.
19096 Pass @code{#f} to not issue a default location.
19100 @deftp {Data Type} certificate-configuration
19101 Data type representing the configuration of a certificate.
19102 This type has the following parameters:
19105 @item @code{name} (default: @i{see below})
19106 This name is used by Certbot for housekeeping and in file paths; it
19107 doesn't affect the content of the certificate itself. To see
19108 certificate names, run @code{certbot certificates}.
19110 Its default is the first provided domain.
19112 @item @code{domains} (default: @code{()})
19113 The first domain provided will be the subject CN of the certificate, and
19114 all domains will be Subject Alternative Names on the certificate.
19116 @item @code{deploy-hook} (default: @code{#f})
19117 Command to be run in a shell once for each successfully issued
19118 certificate. For this command, the shell variable
19119 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
19120 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
19121 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
19122 contain a space-delimited list of renewed certificate domains (for
19123 example, @samp{"example.com www.example.com"}.
19128 For each @code{certificate-configuration}, the certificate is saved to
19129 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
19130 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
19132 @subsection DNS Services
19133 @cindex DNS (domain name system)
19134 @cindex domain name system (DNS)
19136 The @code{(gnu services dns)} module provides services related to the
19137 @dfn{domain name system} (DNS). It provides a server service for hosting
19138 an @emph{authoritative} DNS server for multiple zones, slave or master.
19139 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
19140 caching and forwarding DNS server for the LAN, which uses
19141 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
19143 @subsubheading Knot Service
19145 An example configuration of an authoritative server for two zones, one master
19149 (define-zone-entries example.org.zone
19150 ;; Name TTL Class Type Data
19151 ("@@" "" "IN" "A" "127.0.0.1")
19152 ("@@" "" "IN" "NS" "ns")
19153 ("ns" "" "IN" "A" "127.0.0.1"))
19155 (define master-zone
19156 (knot-zone-configuration
19157 (domain "example.org")
19159 (origin "example.org")
19160 (entries example.org.zone)))))
19163 (knot-zone-configuration
19164 (domain "plop.org")
19165 (dnssec-policy "default")
19166 (master (list "plop-master"))))
19168 (define plop-master
19169 (knot-remote-configuration
19171 (address (list "208.76.58.171"))))
19175 (services (cons* (service knot-service-type
19176 (knot-configuration
19177 (remotes (list plop-master))
19178 (zones (list master-zone slave-zone))))
19183 @deffn {Scheme Variable} knot-service-type
19184 This is the type for the Knot DNS server.
19186 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
19187 zones, that is to say domain names you would buy from a registrar. This server
19188 is not a resolver, meaning that it can only resolve names for which it is
19189 authoritative. This server can be configured to serve zones as a master server
19190 or a slave server as a per-zone basis. Slave zones will get their data from
19191 masters, and will serve it as an authoritative server. From the point of view
19192 of a resolver, there is no difference between master and slave.
19194 The following data types are used to configure the Knot DNS server:
19197 @deftp {Data Type} knot-key-configuration
19198 Data type representing a key.
19199 This type has the following parameters:
19202 @item @code{id} (default: @code{""})
19203 An identifier for other configuration fields to refer to this key. IDs must
19204 be unique and must not be empty.
19206 @item @code{algorithm} (default: @code{#f})
19207 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
19208 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
19209 and @code{'hmac-sha512}.
19211 @item @code{secret} (default: @code{""})
19212 The secret key itself.
19217 @deftp {Data Type} knot-acl-configuration
19218 Data type representing an Access Control List (ACL) configuration.
19219 This type has the following parameters:
19222 @item @code{id} (default: @code{""})
19223 An identifier for ether configuration fields to refer to this key. IDs must be
19224 unique and must not be empty.
19226 @item @code{address} (default: @code{'()})
19227 An ordered list of IP addresses, network subnets, or network ranges represented
19228 with strings. The query must match one of them. Empty value means that
19229 address match is not required.
19231 @item @code{key} (default: @code{'()})
19232 An ordered list of references to keys represented with strings. The string
19233 must match a key ID defined in a @code{knot-key-configuration}. No key means
19234 that a key is not require to match that ACL.
19236 @item @code{action} (default: @code{'()})
19237 An ordered list of actions that are permitted or forbidden by this ACL. Possible
19238 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
19239 and @code{'update}.
19241 @item @code{deny?} (default: @code{#f})
19242 When true, the ACL defines restrictions. Listed actions are forbidden. When
19243 false, listed actions are allowed.
19248 @deftp {Data Type} zone-entry
19249 Data type represnting a record entry in a zone file.
19250 This type has the following parameters:
19253 @item @code{name} (default: @code{"@@"})
19254 The name of the record. @code{"@@"} refers to the origin of the zone. Names
19255 are relative to the origin of the zone. For example, in the @code{example.org}
19256 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
19257 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
19258 refers to @code{ns.example.org}.
19260 @item @code{ttl} (default: @code{""})
19261 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
19263 @item @code{class} (default: @code{"IN"})
19264 The class of the record. Knot currently supports only @code{"IN"} and
19265 partially @code{"CH"}.
19267 @item @code{type} (default: @code{"A"})
19268 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
19269 address), NS (Name Server) and MX (Mail eXchange). Many other types are
19272 @item @code{data} (default: @code{""})
19273 The data contained in the record. For instance an IP address associated with
19274 an A record, or a domain name associated with an NS record. Remember that
19275 domain names are relative to the origin unless they end with a dot.
19280 @deftp {Data Type} zone-file
19281 Data type representing the content of a zone file.
19282 This type has the following parameters:
19285 @item @code{entries} (default: @code{'()})
19286 The list of entries. The SOA record is taken care of, so you don't need to
19287 put it in the list of entries. This list should probably contain an entry
19288 for your primary authoritative DNS server. Other than using a list of entries
19289 directly, you can use @code{define-zone-entries} to define a object containing
19290 the list of entries more easily, that you can later pass to the @code{entries}
19291 field of the @code{zone-file}.
19293 @item @code{origin} (default: @code{""})
19294 The name of your zone. This parameter cannot be empty.
19296 @item @code{ns} (default: @code{"ns"})
19297 The domain of your primary authoritative DNS server. The name is relative to
19298 the origin, unless it ends with a dot. It is mandatory that this primary
19299 DNS server corresponds to an NS record in the zone and that it is associated
19300 to an IP address in the list of entries.
19302 @item @code{mail} (default: @code{"hostmaster"})
19303 An email address people can contact you at, as the owner of the zone. This
19304 is translated as @code{<mail>@@<origin>}.
19306 @item @code{serial} (default: @code{1})
19307 The serial number of the zone. As this is used to keep track of changes by
19308 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
19309 Always increment it when you make a change in your zone.
19311 @item @code{refresh} (default: @code{(* 2 24 3600)})
19312 The frequency at which slaves will do a zone transfer. This value is a number
19313 of seconds. It can be computed by multiplications or with
19314 @code{(string->duration)}.
19316 @item @code{retry} (default: @code{(* 15 60)})
19317 The period after which a slave will retry to contact its master when it fails
19318 to do so a first time.
19320 @item @code{expiry} (default: @code{(* 14 24 3600)})
19321 Default TTL of records. Existing records are considered correct for at most
19322 this amount of time. After this period, resolvers will invalidate their cache
19323 and check again that it still exists.
19325 @item @code{nx} (default: @code{3600})
19326 Default TTL of inexistant records. This delay is usually short because you want
19327 your new domains to reach everyone quickly.
19332 @deftp {Data Type} knot-remote-configuration
19333 Data type representing a remote configuration.
19334 This type has the following parameters:
19337 @item @code{id} (default: @code{""})
19338 An identifier for other configuration fields to refer to this remote. IDs must
19339 be unique and must not be empty.
19341 @item @code{address} (default: @code{'()})
19342 An ordered list of destination IP addresses. Addresses are tried in sequence.
19343 An optional port can be given with the @@ separator. For instance:
19344 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
19346 @item @code{via} (default: @code{'()})
19347 An ordered list of source IP addresses. An empty list will have Knot choose
19348 an appropriate source IP. An optional port can be given with the @@ separator.
19349 The default is to choose at random.
19351 @item @code{key} (default: @code{#f})
19352 A reference to a key, that is a string containing the identifier of a key
19353 defined in a @code{knot-key-configuration} field.
19358 @deftp {Data Type} knot-keystore-configuration
19359 Data type representing a keystore to hold dnssec keys.
19360 This type has the following parameters:
19363 @item @code{id} (default: @code{""})
19364 The id of the keystore. It must not be empty.
19366 @item @code{backend} (default: @code{'pem})
19367 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
19369 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
19370 The configuration string of the backend. An example for the PKCS#11 is:
19371 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
19372 For the pem backend, the string reprensents a path in the file system.
19377 @deftp {Data Type} knot-policy-configuration
19378 Data type representing a dnssec policy. Knot DNS is able to automatically
19379 sign your zones. It can either generate and manage your keys automatically or
19380 use keys that you generate.
19382 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
19383 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
19384 zone. In order to be trusted, the KSK needs to be present in the parent zone
19385 (usually a top-level domain). If your registrar supports dnssec, you will
19386 have to send them your KSK's hash so they can add a DS record in their zone.
19387 This is not automated and need to be done each time you change your KSK.
19389 The policy also defines the lifetime of keys. Usually, ZSK can be changed
19390 easily and use weaker cryptographic functions (they use lower parameters) in
19391 order to sign records quickly, so they are changed often. The KSK however
19392 requires manual interaction with the registrar, so they are changed less often
19393 and use stronger parameters because they sign only one record.
19395 This type has the following parameters:
19398 @item @code{id} (default: @code{""})
19399 The id of the policy. It must not be empty.
19401 @item @code{keystore} (default: @code{"default"})
19402 A reference to a keystore, that is a string containing the identifier of a
19403 keystore defined in a @code{knot-keystore-configuration} field. The
19404 @code{"default"} identifier means the default keystore (a kasp database that
19405 was setup by this service).
19407 @item @code{manual?} (default: @code{#f})
19408 Whether the key management is manual or automatic.
19410 @item @code{single-type-signing?} (default: @code{#f})
19411 When @code{#t}, use the Single-Type Signing Scheme.
19413 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
19414 An algorithm of signing keys and issued signatures.
19416 @item @code{ksk-size} (default: @code{256})
19417 The length of the KSK. Note that this value is correct for the default
19418 algorithm, but would be unsecure for other algorithms.
19420 @item @code{zsk-size} (default: @code{256})
19421 The length of the ZSK. Note that this value is correct for the default
19422 algorithm, but would be unsecure for other algorithms.
19424 @item @code{dnskey-ttl} (default: @code{'default})
19425 The TTL value for DNSKEY records added into zone apex. The special
19426 @code{'default} value means same as the zone SOA TTL.
19428 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
19429 The period between ZSK publication and the next rollover initiation.
19431 @item @code{propagation-delay} (default: @code{(* 24 3600)})
19432 An extra delay added for each key rollover step. This value should be high
19433 enough to cover propagation of data from the master server to all slaves.
19435 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
19436 A validity period of newly issued signatures.
19438 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
19439 A period how long before a signature expiration the signature will be refreshed.
19441 @item @code{nsec3?} (default: @code{#f})
19442 When @code{#t}, NSEC3 will be used instead of NSEC.
19444 @item @code{nsec3-iterations} (default: @code{5})
19445 The number of additional times the hashing is performed.
19447 @item @code{nsec3-salt-length} (default: @code{8})
19448 The length of a salt field in octets, which is appended to the original owner
19449 name before hashing.
19451 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
19452 The validity period of newly issued salt field.
19457 @deftp {Data Type} knot-zone-configuration
19458 Data type representing a zone served by Knot.
19459 This type has the following parameters:
19462 @item @code{domain} (default: @code{""})
19463 The domain served by this configuration. It must not be empty.
19465 @item @code{file} (default: @code{""})
19466 The file where this zone is saved. This parameter is ignored by master zones.
19467 Empty means default location that depends on the domain name.
19469 @item @code{zone} (default: @code{(zone-file)})
19470 The content of the zone file. This parameter is ignored by slave zones. It
19471 must contain a zone-file record.
19473 @item @code{master} (default: @code{'()})
19474 A list of master remotes. When empty, this zone is a master. When set, this
19475 zone is a slave. This is a list of remotes identifiers.
19477 @item @code{ddns-master} (default: @code{#f})
19478 The main master. When empty, it defaults to the first master in the list of
19481 @item @code{notify} (default: @code{'()})
19482 A list of slave remote identifiers.
19484 @item @code{acl} (default: @code{'()})
19485 A list of acl identifiers.
19487 @item @code{semantic-checks?} (default: @code{#f})
19488 When set, this adds more semantic checks to the zone.
19490 @item @code{disable-any?} (default: @code{#f})
19491 When set, this forbids queries of the ANY type.
19493 @item @code{zonefile-sync} (default: @code{0})
19494 The delay between a modification in memory and on disk. 0 means immediate
19497 @item @code{serial-policy} (default: @code{'increment})
19498 A policy between @code{'increment} and @code{'unixtime}.
19503 @deftp {Data Type} knot-configuration
19504 Data type representing the Knot configuration.
19505 This type has the following parameters:
19508 @item @code{knot} (default: @code{knot})
19511 @item @code{run-directory} (default: @code{"/var/run/knot"})
19512 The run directory. This directory will be used for pid file and sockets.
19514 @item @code{listen-v4} (default: @code{"0.0.0.0"})
19515 An ip address on which to listen.
19517 @item @code{listen-v6} (default: @code{"::"})
19518 An ip address on which to listen.
19520 @item @code{listen-port} (default: @code{53})
19521 A port on which to listen.
19523 @item @code{keys} (default: @code{'()})
19524 The list of knot-key-configuration used by this configuration.
19526 @item @code{acls} (default: @code{'()})
19527 The list of knot-acl-configuration used by this configuration.
19529 @item @code{remotes} (default: @code{'()})
19530 The list of knot-remote-configuration used by this configuration.
19532 @item @code{zones} (default: @code{'()})
19533 The list of knot-zone-configuration used by this configuration.
19538 @subsubheading Dnsmasq Service
19540 @deffn {Scheme Variable} dnsmasq-service-type
19541 This is the type of the dnsmasq service, whose value should be an
19542 @code{dnsmasq-configuration} object as in this example:
19545 (service dnsmasq-service-type
19546 (dnsmasq-configuration
19548 (servers '("192.168.1.1"))))
19552 @deftp {Data Type} dnsmasq-configuration
19553 Data type representing the configuration of dnsmasq.
19556 @item @code{package} (default: @var{dnsmasq})
19557 Package object of the dnsmasq server.
19559 @item @code{no-hosts?} (default: @code{#f})
19560 When true, don't read the hostnames in /etc/hosts.
19562 @item @code{port} (default: @code{53})
19563 The port to listen on. Setting this to zero completely disables DNS
19564 responses, leaving only DHCP and/or TFTP functions.
19566 @item @code{local-service?} (default: @code{#t})
19567 Accept DNS queries only from hosts whose address is on a local subnet,
19568 ie a subnet for which an interface exists on the server.
19570 @item @code{listen-addresses} (default: @code{'()})
19571 Listen on the given IP addresses.
19573 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
19574 The file to read the IP address of the upstream nameservers from.
19576 @item @code{no-resolv?} (default: @code{#f})
19577 When true, don't read @var{resolv-file}.
19579 @item @code{servers} (default: @code{'()})
19580 Specify IP address of upstream servers directly.
19582 @item @code{cache-size} (default: @code{150})
19583 Set the size of dnsmasq's cache. Setting the cache size to zero
19586 @item @code{negative-cache?} (default: @code{#t})
19587 When false, disable negative caching.
19592 @subsubheading ddclient Service
19595 The ddclient service described below runs the ddclient daemon, which takes
19596 care of automatically updating DNS entries for service providers such as
19597 @uref{https://dyn.com/dns/, Dyn}.
19599 The following example show instantiates the service with its default
19603 (service ddclient-service-type)
19606 Note that ddclient needs to access credentials that are stored in a
19607 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
19608 @code{secret-file} below.) You are expected to create this file manually, in
19609 an ``out-of-band'' fashion (you @emph{could} make this file part of the
19610 service configuration, for instance by using @code{plain-file}, but it will be
19611 world-readable @i{via} @file{/gnu/store}.) See the examples in the
19612 @file{share/ddclient} directory of the @code{ddclient} package.
19614 @c %start of fragment
19616 Available @code{ddclient-configuration} fields are:
19618 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
19619 The ddclient package.
19623 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
19624 The period after which ddclient will retry to check IP and domain name.
19626 Defaults to @samp{300}.
19630 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
19631 Use syslog for the output.
19633 Defaults to @samp{#t}.
19637 @deftypevr {@code{ddclient-configuration} parameter} string mail
19640 Defaults to @samp{"root"}.
19644 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
19645 Mail failed update to user.
19647 Defaults to @samp{"root"}.
19651 @deftypevr {@code{ddclient-configuration} parameter} string pid
19652 The ddclient PID file.
19654 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
19658 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
19659 Enable SSL support.
19661 Defaults to @samp{#t}.
19665 @deftypevr {@code{ddclient-configuration} parameter} string user
19666 Specifies the user name or ID that is used when running ddclient
19669 Defaults to @samp{"ddclient"}.
19673 @deftypevr {@code{ddclient-configuration} parameter} string group
19674 Group of the user who will run the ddclient program.
19676 Defaults to @samp{"ddclient"}.
19680 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
19681 Secret file which will be appended to @file{ddclient.conf} file. This
19682 file contains credentials for use by ddclient. You are expected to
19683 create it manually.
19685 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
19689 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
19690 Extra options will be appended to @file{ddclient.conf} file.
19692 Defaults to @samp{()}.
19697 @c %end of fragment
19701 @subsection VPN Services
19702 @cindex VPN (virtual private network)
19703 @cindex virtual private network (VPN)
19705 The @code{(gnu services vpn)} module provides services related to
19706 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
19707 your machine to connect to a VPN, and a @emph{servire} service for your machine
19708 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
19710 @deffn {Scheme Procedure} openvpn-client-service @
19711 [#:config (openvpn-client-configuration)]
19713 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
19716 @deffn {Scheme Procedure} openvpn-server-service @
19717 [#:config (openvpn-server-configuration)]
19719 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
19721 Both can be run simultaneously.
19724 @c %automatically generated documentation
19726 Available @code{openvpn-client-configuration} fields are:
19728 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
19729 The OpenVPN package.
19733 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
19734 The OpenVPN pid file.
19736 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
19740 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
19741 The protocol (UDP or TCP) used to open a channel between clients and
19744 Defaults to @samp{udp}.
19748 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
19749 The device type used to represent the VPN connection.
19751 Defaults to @samp{tun}.
19755 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
19756 The certificate authority to check connections against.
19758 Defaults to @samp{"/etc/openvpn/ca.crt"}.
19762 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
19763 The certificate of the machine the daemon is running on. It should be
19764 signed by the authority given in @code{ca}.
19766 Defaults to @samp{"/etc/openvpn/client.crt"}.
19770 @deftypevr {@code{openvpn-client-configuration} parameter} string key
19771 The key of the machine the daemon is running on. It must be the key whose
19772 certificate is @code{cert}.
19774 Defaults to @samp{"/etc/openvpn/client.key"}.
19778 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
19779 Whether to use the lzo compression algorithm.
19781 Defaults to @samp{#t}.
19785 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
19786 Don't re-read key files across SIGUSR1 or --ping-restart.
19788 Defaults to @samp{#t}.
19792 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
19793 Don't close and reopen TUN/TAP device or run up/down scripts across
19794 SIGUSR1 or --ping-restart restarts.
19796 Defaults to @samp{#t}.
19800 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
19803 Defaults to @samp{3}.
19807 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
19808 Add an additional layer of HMAC authentication on top of the TLS control
19809 channel to protect against DoS attacks.
19811 Defaults to @samp{#f}.
19815 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
19816 Whether to check the server certificate has server usage extension.
19818 Defaults to @samp{#t}.
19822 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
19823 Bind to a specific local port number.
19825 Defaults to @samp{#f}.
19829 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
19830 Retry resolving server address.
19832 Defaults to @samp{#t}.
19836 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
19837 A list of remote servers to connect to.
19839 Defaults to @samp{()}.
19841 Available @code{openvpn-remote-configuration} fields are:
19843 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
19846 Defaults to @samp{"my-server"}.
19850 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
19851 Port number the server listens to.
19853 Defaults to @samp{1194}.
19858 @c %end of automatic openvpn-client documentation
19860 @c %automatically generated documentation
19862 Available @code{openvpn-server-configuration} fields are:
19864 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
19865 The OpenVPN package.
19869 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
19870 The OpenVPN pid file.
19872 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
19876 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
19877 The protocol (UDP or TCP) used to open a channel between clients and
19880 Defaults to @samp{udp}.
19884 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
19885 The device type used to represent the VPN connection.
19887 Defaults to @samp{tun}.
19891 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
19892 The certificate authority to check connections against.
19894 Defaults to @samp{"/etc/openvpn/ca.crt"}.
19898 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
19899 The certificate of the machine the daemon is running on. It should be
19900 signed by the authority given in @code{ca}.
19902 Defaults to @samp{"/etc/openvpn/client.crt"}.
19906 @deftypevr {@code{openvpn-server-configuration} parameter} string key
19907 The key of the machine the daemon is running on. It must be the key whose
19908 certificate is @code{cert}.
19910 Defaults to @samp{"/etc/openvpn/client.key"}.
19914 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
19915 Whether to use the lzo compression algorithm.
19917 Defaults to @samp{#t}.
19921 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
19922 Don't re-read key files across SIGUSR1 or --ping-restart.
19924 Defaults to @samp{#t}.
19928 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
19929 Don't close and reopen TUN/TAP device or run up/down scripts across
19930 SIGUSR1 or --ping-restart restarts.
19932 Defaults to @samp{#t}.
19936 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
19939 Defaults to @samp{3}.
19943 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
19944 Add an additional layer of HMAC authentication on top of the TLS control
19945 channel to protect against DoS attacks.
19947 Defaults to @samp{#f}.
19951 @deftypevr {@code{openvpn-server-configuration} parameter} number port
19952 Specifies the port number on which the server listens.
19954 Defaults to @samp{1194}.
19958 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
19959 An ip and mask specifying the subnet inside the virtual network.
19961 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
19965 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
19966 A CIDR notation specifying the IPv6 subnet inside the virtual network.
19968 Defaults to @samp{#f}.
19972 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
19973 The Diffie-Hellman parameters file.
19975 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
19979 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
19980 The file that records client IPs.
19982 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
19986 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
19987 When true, the server will act as a gateway for its clients.
19989 Defaults to @samp{#f}.
19993 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
19994 When true, clients are allowed to talk to each other inside the VPN.
19996 Defaults to @samp{#f}.
20000 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
20001 Causes ping-like messages to be sent back and forth over the link so
20002 that each side knows when the other side has gone down. @code{keepalive}
20003 requires a pair. The first element is the period of the ping sending,
20004 and the second element is the timeout before considering the other side
20009 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
20010 The maximum number of clients.
20012 Defaults to @samp{100}.
20016 @deftypevr {@code{openvpn-server-configuration} parameter} string status
20017 The status file. This file shows a small report on current connection.
20018 It is truncated and rewritten every minute.
20020 Defaults to @samp{"/var/run/openvpn/status"}.
20024 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
20025 The list of configuration for some clients.
20027 Defaults to @samp{()}.
20029 Available @code{openvpn-ccd-configuration} fields are:
20031 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
20034 Defaults to @samp{"client"}.
20038 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
20041 Defaults to @samp{#f}.
20045 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
20048 Defaults to @samp{#f}.
20055 @c %end of automatic openvpn-server documentation
20058 @node Network File System
20059 @subsection Network File System
20062 The @code{(gnu services nfs)} module provides the following services,
20063 which are most commonly used in relation to mounting or exporting
20064 directory trees as @dfn{network file systems} (NFS).
20066 @subsubheading RPC Bind Service
20069 The RPC Bind service provides a facility to map program numbers into
20070 universal addresses.
20071 Many NFS related services use this facility. Hence it is automatically
20072 started when a dependent service starts.
20074 @defvr {Scheme Variable} rpcbind-service-type
20075 A service type for the RPC portmapper daemon.
20079 @deftp {Data Type} rpcbind-configuration
20080 Data type representing the configuration of the RPC Bind Service.
20081 This type has the following parameters:
20083 @item @code{rpcbind} (default: @code{rpcbind})
20084 The rpcbind package to use.
20086 @item @code{warm-start?} (default: @code{#t})
20087 If this parameter is @code{#t}, then the daemon will read a
20088 state file on startup thus reloading state information saved by a previous
20094 @subsubheading Pipefs Pseudo File System
20098 The pipefs file system is used to transfer NFS related data
20099 between the kernel and user space programs.
20101 @defvr {Scheme Variable} pipefs-service-type
20102 A service type for the pipefs pseudo file system.
20105 @deftp {Data Type} pipefs-configuration
20106 Data type representing the configuration of the pipefs pseudo file system service.
20107 This type has the following parameters:
20109 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
20110 The directory to which the file system is to be attached.
20115 @subsubheading GSS Daemon Service
20118 @cindex global security system
20120 The @dfn{global security system} (GSS) daemon provides strong security for RPC
20122 Before exchanging RPC requests an RPC client must establish a security
20123 context. Typically this is done using the Kerberos command @command{kinit}
20124 or automatically at login time using PAM services (@pxref{Kerberos Services}).
20126 @defvr {Scheme Variable} gss-service-type
20127 A service type for the Global Security System (GSS) daemon.
20130 @deftp {Data Type} gss-configuration
20131 Data type representing the configuration of the GSS daemon service.
20132 This type has the following parameters:
20134 @item @code{nfs-utils} (default: @code{nfs-utils})
20135 The package in which the @command{rpc.gssd} command is to be found.
20137 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
20138 The directory where the pipefs file system is mounted.
20144 @subsubheading IDMAP Daemon Service
20146 @cindex name mapper
20148 The idmap daemon service provides mapping between user IDs and user names.
20149 Typically it is required in order to access file systems mounted via NFSv4.
20151 @defvr {Scheme Variable} idmap-service-type
20152 A service type for the Identity Mapper (IDMAP) daemon.
20155 @deftp {Data Type} idmap-configuration
20156 Data type representing the configuration of the IDMAP daemon service.
20157 This type has the following parameters:
20159 @item @code{nfs-utils} (default: @code{nfs-utils})
20160 The package in which the @command{rpc.idmapd} command is to be found.
20162 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
20163 The directory where the pipefs file system is mounted.
20165 @item @code{domain} (default: @code{#f})
20166 The local NFSv4 domain name.
20167 This must be a string or @code{#f}.
20168 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
20173 @node Continuous Integration
20174 @subsection Continuous Integration
20176 @cindex continuous integration
20177 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
20178 continuous integration tool for Guix. It can be used both for development and
20179 for providing substitutes to others (@pxref{Substitutes}).
20181 The @code{(gnu services cuirass)} module provides the following service.
20183 @defvr {Scheme Procedure} cuirass-service-type
20184 The type of the Cuirass service. Its value must be a
20185 @code{cuirass-configuration} object, as described below.
20188 To add build jobs, you have to set the @code{specifications} field of the
20189 configuration. Here is an example of a service that polls the Guix repository
20190 and builds the packages from a manifest. Some of the packages are defined in
20191 the @code{"custom-packages"} input, which is the equivalent of
20192 @code{GUIX_PACKAGE_PATH}.
20195 (define %cuirass-specs
20197 '((#:name . "my-manifest")
20198 (#:load-path-inputs . ("guix"))
20199 (#:package-path-inputs . ("custom-packages"))
20200 (#:proc-input . "guix")
20201 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
20202 (#:proc . cuirass-jobs)
20203 (#:proc-args . ((subset . "manifests")
20204 (systems . ("x86_64-linux"))
20205 (manifests . (("config" . "guix/manifest.scm")))))
20206 (#:inputs . (((#:name . "guix")
20207 (#:url . "git://git.savannah.gnu.org/guix.git")
20208 (#:load-path . ".")
20209 (#:branch . "master")
20210 (#:no-compile? . #t))
20211 ((#:name . "config")
20212 (#:url . "git://git.example.org/config.git")
20213 (#:load-path . ".")
20214 (#:branch . "master")
20215 (#:no-compile? . #t))
20216 ((#:name . "custom-packages")
20217 (#:url . "git://git.example.org/custom-packages.git")
20218 (#:load-path . ".")
20219 (#:branch . "master")
20220 (#:no-compile? . #t)))))))
20222 (service cuirass-service-type
20223 (cuirass-configuration
20224 (specifications %cuirass-specs)))
20227 While information related to build jobs is located directly in the
20228 specifications, global settings for the @command{cuirass} process are
20229 accessible in other @code{cuirass-configuration} fields.
20231 @deftp {Data Type} cuirass-configuration
20232 Data type representing the configuration of Cuirass.
20235 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
20236 Location of the log file.
20238 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
20239 Location of the repository cache.
20241 @item @code{user} (default: @code{"cuirass"})
20242 Owner of the @code{cuirass} process.
20244 @item @code{group} (default: @code{"cuirass"})
20245 Owner's group of the @code{cuirass} process.
20247 @item @code{interval} (default: @code{60})
20248 Number of seconds between the poll of the repositories followed by the
20251 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
20252 Location of sqlite database which contains the build results and previously
20253 added specifications.
20255 @item @code{ttl} (default: @code{(* 30 24 3600)})
20256 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
20257 are registered for build results. This means that build results are protected
20258 from garbage collection for at least @var{ttl} seconds.
20260 @item @code{port} (default: @code{8081})
20261 Port number used by the HTTP server.
20263 @item --listen=@var{host}
20264 Listen on the network interface for @var{host}. The default is to
20265 accept connections from localhost.
20267 @item @code{specifications} (default: @code{#~'()})
20268 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
20269 where a specification is an association list
20270 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
20271 keys are keywords (@code{#:keyword-example}) as shown in the example
20274 @item @code{use-substitutes?} (default: @code{#f})
20275 This allows using substitutes to avoid building every dependencies of a job
20278 @item @code{one-shot?} (default: @code{#f})
20279 Only evaluate specifications and build derivations once.
20281 @item @code{fallback?} (default: @code{#f})
20282 When substituting a pre-built binary fails, fall back to building
20285 @item @code{cuirass} (default: @code{cuirass})
20286 The Cuirass package to use.
20290 @node Power Management Services
20291 @subsection Power Management Services
20294 @cindex power management with TLP
20295 @subsubheading TLP daemon
20297 The @code{(gnu services pm)} module provides a Guix service definition
20298 for the Linux power management tool TLP.
20300 TLP enables various powersaving modes in userspace and kernel.
20301 Contrary to @code{upower-service}, it is not a passive,
20302 monitoring tool, as it will apply custom settings each time a new power
20303 source is detected. More information can be found at
20304 @uref{http://linrunner.de/en/tlp/tlp.html, TLP home page}.
20306 @deffn {Scheme Variable} tlp-service-type
20307 The service type for the TLP tool. Its value should be a valid
20308 TLP configuration (see below). To use the default settings, simply
20311 (service tlp-service-type)
20315 By default TLP does not need much configuration but most TLP parameters
20316 can be tweaked using @code{tlp-configuration}.
20318 Each parameter definition is preceded by its type; for example,
20319 @samp{boolean foo} indicates that the @code{foo} parameter
20320 should be specified as a boolean. Types starting with
20321 @code{maybe-} denote parameters that won't show up in TLP config file
20322 when their value is @code{'disabled}.
20324 @c The following documentation was initially generated by
20325 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
20326 @c documentation is better, so we shouldn't hesitate to edit below as
20327 @c needed. However if the change you want to make to this documentation
20328 @c can be done in an automated way, it's probably easier to change
20329 @c (generate-documentation) than to make it below and have to deal with
20330 @c the churn as TLP updates.
20332 Available @code{tlp-configuration} fields are:
20334 @deftypevr {@code{tlp-configuration} parameter} package tlp
20339 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
20340 Set to true if you wish to enable TLP.
20342 Defaults to @samp{#t}.
20346 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
20347 Default mode when no power supply can be detected. Alternatives are AC
20350 Defaults to @samp{"AC"}.
20354 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
20355 Number of seconds Linux kernel has to wait after the disk goes idle,
20356 before syncing on AC.
20358 Defaults to @samp{0}.
20362 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
20363 Same as @code{disk-idle-ac} but on BAT mode.
20365 Defaults to @samp{2}.
20369 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
20370 Dirty pages flushing periodicity, expressed in seconds.
20372 Defaults to @samp{15}.
20376 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
20377 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
20379 Defaults to @samp{60}.
20383 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
20384 CPU frequency scaling governor on AC mode. With intel_pstate driver,
20385 alternatives are powersave and performance. With acpi-cpufreq driver,
20386 alternatives are ondemand, powersave, performance and conservative.
20388 Defaults to @samp{disabled}.
20392 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
20393 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
20395 Defaults to @samp{disabled}.
20399 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
20400 Set the min available frequency for the scaling governor on AC.
20402 Defaults to @samp{disabled}.
20406 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
20407 Set the max available frequency for the scaling governor on AC.
20409 Defaults to @samp{disabled}.
20413 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
20414 Set the min available frequency for the scaling governor on BAT.
20416 Defaults to @samp{disabled}.
20420 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
20421 Set the max available frequency for the scaling governor on BAT.
20423 Defaults to @samp{disabled}.
20427 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
20428 Limit the min P-state to control the power dissipation of the CPU, in AC
20429 mode. Values are stated as a percentage of the available performance.
20431 Defaults to @samp{disabled}.
20435 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
20436 Limit the max P-state to control the power dissipation of the CPU, in AC
20437 mode. Values are stated as a percentage of the available performance.
20439 Defaults to @samp{disabled}.
20443 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
20444 Same as @code{cpu-min-perf-on-ac} on BAT mode.
20446 Defaults to @samp{disabled}.
20450 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
20451 Same as @code{cpu-max-perf-on-ac} on BAT mode.
20453 Defaults to @samp{disabled}.
20457 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
20458 Enable CPU turbo boost feature on AC mode.
20460 Defaults to @samp{disabled}.
20464 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
20465 Same as @code{cpu-boost-on-ac?} on BAT mode.
20467 Defaults to @samp{disabled}.
20471 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
20472 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
20473 used under light load conditions.
20475 Defaults to @samp{#f}.
20479 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
20480 Same as @code{sched-powersave-on-ac?} but on BAT mode.
20482 Defaults to @samp{#t}.
20486 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
20487 Enable Linux kernel NMI watchdog.
20489 Defaults to @samp{#f}.
20493 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
20494 For Linux kernels with PHC patch applied, change CPU voltages. An
20495 example value would be @samp{"F:V F:V F:V F:V"}.
20497 Defaults to @samp{disabled}.
20501 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
20502 Set CPU performance versus energy saving policy on AC. Alternatives are
20503 performance, normal, powersave.
20505 Defaults to @samp{"performance"}.
20509 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
20510 Same as @code{energy-perf-policy-ac} but on BAT mode.
20512 Defaults to @samp{"powersave"}.
20516 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
20521 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
20522 Hard disk advanced power management level.
20526 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
20527 Same as @code{disk-apm-bat} but on BAT mode.
20531 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
20532 Hard disk spin down timeout. One value has to be specified for each
20533 declared hard disk.
20535 Defaults to @samp{disabled}.
20539 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
20540 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
20542 Defaults to @samp{disabled}.
20546 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
20547 Select IO scheduler for disk devices. One value has to be specified for
20548 each declared hard disk. Example alternatives are cfq, deadline and
20551 Defaults to @samp{disabled}.
20555 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
20556 SATA aggressive link power management (ALPM) level. Alternatives are
20557 min_power, medium_power, max_performance.
20559 Defaults to @samp{"max_performance"}.
20563 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
20564 Same as @code{sata-linkpwr-ac} but on BAT mode.
20566 Defaults to @samp{"min_power"}.
20570 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
20571 Exclude specified SATA host devices for link power management.
20573 Defaults to @samp{disabled}.
20577 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
20578 Enable Runtime Power Management for AHCI controller and disks on AC
20581 Defaults to @samp{disabled}.
20585 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
20586 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
20588 Defaults to @samp{disabled}.
20592 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
20593 Seconds of inactivity before disk is suspended.
20595 Defaults to @samp{15}.
20599 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
20600 PCI Express Active State Power Management level. Alternatives are
20601 default, performance, powersave.
20603 Defaults to @samp{"performance"}.
20607 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
20608 Same as @code{pcie-aspm-ac} but on BAT mode.
20610 Defaults to @samp{"powersave"}.
20614 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
20615 Radeon graphics clock speed level. Alternatives are low, mid, high,
20618 Defaults to @samp{"high"}.
20622 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
20623 Same as @code{radeon-power-ac} but on BAT mode.
20625 Defaults to @samp{"low"}.
20629 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
20630 Radeon dynamic power management method (DPM). Alternatives are battery,
20633 Defaults to @samp{"performance"}.
20637 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
20638 Same as @code{radeon-dpm-state-ac} but on BAT mode.
20640 Defaults to @samp{"battery"}.
20644 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
20645 Radeon DPM performance level. Alternatives are auto, low, high.
20647 Defaults to @samp{"auto"}.
20651 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
20652 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
20654 Defaults to @samp{"auto"}.
20658 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
20659 Wifi power saving mode.
20661 Defaults to @samp{#f}.
20665 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
20666 Same as @code{wifi-power-ac?} but on BAT mode.
20668 Defaults to @samp{#t}.
20672 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
20673 Disable wake on LAN.
20675 Defaults to @samp{#t}.
20679 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
20680 Timeout duration in seconds before activating audio power saving on
20681 Intel HDA and AC97 devices. A value of 0 disables power saving.
20683 Defaults to @samp{0}.
20687 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
20688 Same as @code{sound-powersave-ac} but on BAT mode.
20690 Defaults to @samp{1}.
20694 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
20695 Disable controller in powersaving mode on Intel HDA devices.
20697 Defaults to @samp{#t}.
20701 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
20702 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
20703 powered on again by releasing (and reinserting) the eject lever or by
20704 pressing the disc eject button on newer models.
20706 Defaults to @samp{#f}.
20710 @deftypevr {@code{tlp-configuration} parameter} string bay-device
20711 Name of the optical drive device to power off.
20713 Defaults to @samp{"sr0"}.
20717 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
20718 Runtime Power Management for PCI(e) bus devices. Alternatives are on
20721 Defaults to @samp{"on"}.
20725 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
20726 Same as @code{runtime-pm-ac} but on BAT mode.
20728 Defaults to @samp{"auto"}.
20732 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
20733 Runtime Power Management for all PCI(e) bus devices, except blacklisted
20736 Defaults to @samp{#t}.
20740 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
20741 Exclude specified PCI(e) device addresses from Runtime Power Management.
20743 Defaults to @samp{disabled}.
20747 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
20748 Exclude PCI(e) devices assigned to the specified drivers from Runtime
20753 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
20754 Enable USB autosuspend feature.
20756 Defaults to @samp{#t}.
20760 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
20761 Exclude specified devices from USB autosuspend.
20763 Defaults to @samp{disabled}.
20767 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
20768 Exclude WWAN devices from USB autosuspend.
20770 Defaults to @samp{#t}.
20774 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
20775 Include specified devices into USB autosuspend, even if they are already
20776 excluded by the driver or via @code{usb-blacklist-wwan?}.
20778 Defaults to @samp{disabled}.
20782 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
20783 Enable USB autosuspend before shutdown.
20785 Defaults to @samp{disabled}.
20789 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
20790 Restore radio device state (bluetooth, wifi, wwan) from previous
20791 shutdown on system startup.
20793 Defaults to @samp{#f}.
20798 @cindex CPU frequency scaling with thermald
20799 @subsubheading Thermald daemon
20801 The @code{(gnu services pm)} module provides an interface to
20802 thermald, a CPU frequency scaling service which helps prevent overheating.
20804 @defvr {Scheme Variable} thermald-service-type
20805 This is the service type for
20806 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
20807 Thermal Daemon, which is responsible for controlling the thermal state
20808 of processors and preventing overheating.
20811 @deftp {Data Type} thermald-configuration
20812 Data type representing the configuration of @code{thermald-service-type}.
20815 @item @code{ignore-cpuid-check?} (default: @code{#f})
20816 Ignore cpuid check for supported CPU models.
20818 @item @code{thermald} (default: @var{thermald})
20819 Package object of thermald.
20824 @node Audio Services
20825 @subsection Audio Services
20827 The @code{(gnu services audio)} module provides a service to start MPD
20828 (the Music Player Daemon).
20831 @subsubheading Music Player Daemon
20833 The Music Player Daemon (MPD) is a service that can play music while
20834 being controlled from the local machine or over the network by a variety
20837 The following example shows how one might run @code{mpd} as user
20838 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
20841 (service mpd-service-type
20847 @defvr {Scheme Variable} mpd-service-type
20848 The service type for @command{mpd}
20851 @deftp {Data Type} mpd-configuration
20852 Data type representing the configuration of @command{mpd}.
20855 @item @code{user} (default: @code{"mpd"})
20856 The user to run mpd as.
20858 @item @code{music-dir} (default: @code{"~/Music"})
20859 The directory to scan for music files.
20861 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
20862 The directory to store playlists.
20864 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
20865 The location of the music database.
20867 @item @code{state-file} (default: @code{"~/.mpd/state"})
20868 The location of the file that stores current MPD's state.
20870 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
20871 The location of the sticker database.
20873 @item @code{port} (default: @code{"6600"})
20874 The port to run mpd on.
20876 @item @code{address} (default: @code{"any"})
20877 The address that mpd will bind to. To use a Unix domain socket,
20878 an absolute path can be specified here.
20883 @node Virtualization Services
20884 @subsection Virtualization services
20886 The @code{(gnu services virtualization)} module provides services for
20887 the libvirt and virtlog daemons, as well as other virtualization-related
20890 @subsubheading Libvirt daemon
20891 @code{libvirtd} is the server side daemon component of the libvirt
20892 virtualization management system. This daemon runs on host servers
20893 and performs required management tasks for virtualized guests.
20895 @deffn {Scheme Variable} libvirt-service-type
20896 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
20897 Its value must be a @code{libvirt-configuration}.
20900 (service libvirt-service-type
20901 (libvirt-configuration
20902 (unix-sock-group "libvirt")
20903 (tls-port "16555")))
20907 @c Auto-generated with (generate-libvirt-documentation)
20908 Available @code{libvirt-configuration} fields are:
20910 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
20915 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
20916 Flag listening for secure TLS connections on the public TCP/IP port.
20917 must set @code{listen} for this to have any effect.
20919 It is necessary to setup a CA and issue server certificates before using
20922 Defaults to @samp{#t}.
20926 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
20927 Listen for unencrypted TCP connections on the public TCP/IP port. must
20928 set @code{listen} for this to have any effect.
20930 Using the TCP socket requires SASL authentication by default. Only SASL
20931 mechanisms which support data encryption are allowed. This is
20932 DIGEST_MD5 and GSSAPI (Kerberos5)
20934 Defaults to @samp{#f}.
20938 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
20939 Port for accepting secure TLS connections This can be a port number, or
20942 Defaults to @samp{"16514"}.
20946 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
20947 Port for accepting insecure TCP connections This can be a port number,
20950 Defaults to @samp{"16509"}.
20954 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
20955 IP address or hostname used for client connections.
20957 Defaults to @samp{"0.0.0.0"}.
20961 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
20962 Flag toggling mDNS advertisement of the libvirt service.
20964 Alternatively can disable for all services on a host by stopping the
20967 Defaults to @samp{#f}.
20971 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
20972 Default mDNS advertisement name. This must be unique on the immediate
20975 Defaults to @samp{"Virtualization Host <hostname>"}.
20979 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
20980 UNIX domain socket group ownership. This can be used to allow a
20981 'trusted' set of users access to management capabilities without
20984 Defaults to @samp{"root"}.
20988 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
20989 UNIX socket permissions for the R/O socket. This is used for monitoring
20992 Defaults to @samp{"0777"}.
20996 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
20997 UNIX socket permissions for the R/W socket. Default allows only root.
20998 If PolicyKit is enabled on the socket, the default will change to allow
20999 everyone (eg, 0777)
21001 Defaults to @samp{"0770"}.
21005 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
21006 UNIX socket permissions for the admin socket. Default allows only owner
21007 (root), do not change it unless you are sure to whom you are exposing
21010 Defaults to @samp{"0777"}.
21014 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
21015 The directory in which sockets will be found/created.
21017 Defaults to @samp{"/var/run/libvirt"}.
21021 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
21022 Authentication scheme for UNIX read-only sockets. By default socket
21023 permissions allow anyone to connect
21025 Defaults to @samp{"polkit"}.
21029 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
21030 Authentication scheme for UNIX read-write sockets. By default socket
21031 permissions only allow root. If PolicyKit support was compiled into
21032 libvirt, the default will be to use 'polkit' auth.
21034 Defaults to @samp{"polkit"}.
21038 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
21039 Authentication scheme for TCP sockets. If you don't enable SASL, then
21040 all TCP traffic is cleartext. Don't do this outside of a dev/test
21043 Defaults to @samp{"sasl"}.
21047 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
21048 Authentication scheme for TLS sockets. TLS sockets already have
21049 encryption provided by the TLS layer, and limited authentication is done
21052 It is possible to make use of any SASL authentication mechanism as well,
21053 by using 'sasl' for this option
21055 Defaults to @samp{"none"}.
21059 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
21060 API access control scheme.
21062 By default an authenticated user is allowed access to all APIs. Access
21063 drivers can place restrictions on this.
21065 Defaults to @samp{()}.
21069 @deftypevr {@code{libvirt-configuration} parameter} string key-file
21070 Server key file path. If set to an empty string, then no private key is
21073 Defaults to @samp{""}.
21077 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
21078 Server key file path. If set to an empty string, then no certificate is
21081 Defaults to @samp{""}.
21085 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
21086 Server key file path. If set to an empty string, then no CA certificate
21089 Defaults to @samp{""}.
21093 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
21094 Certificate revocation list path. If set to an empty string, then no
21097 Defaults to @samp{""}.
21101 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
21102 Disable verification of our own server certificates.
21104 When libvirtd starts it performs some sanity checks against its own
21107 Defaults to @samp{#f}.
21111 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
21112 Disable verification of client certificates.
21114 Client certificate verification is the primary authentication mechanism.
21115 Any client which does not present a certificate signed by the CA will be
21118 Defaults to @samp{#f}.
21122 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
21123 Whitelist of allowed x509 Distinguished Name.
21125 Defaults to @samp{()}.
21129 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
21130 Whitelist of allowed SASL usernames. The format for username depends on
21131 the SASL authentication mechanism.
21133 Defaults to @samp{()}.
21137 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
21138 Override the compile time default TLS priority string. The default is
21139 usually "NORMAL" unless overridden at build time. Only set this is it
21140 is desired for libvirt to deviate from the global default settings.
21142 Defaults to @samp{"NORMAL"}.
21146 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
21147 Maximum number of concurrent client connections to allow over all
21150 Defaults to @samp{5000}.
21154 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
21155 Maximum length of queue of connections waiting to be accepted by the
21156 daemon. Note, that some protocols supporting retransmission may obey
21157 this so that a later reattempt at connection succeeds.
21159 Defaults to @samp{1000}.
21163 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
21164 Maximum length of queue of accepted but not yet authenticated clients.
21165 Set this to zero to turn this feature off
21167 Defaults to @samp{20}.
21171 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
21172 Number of workers to start up initially.
21174 Defaults to @samp{5}.
21178 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
21179 Maximum number of worker threads.
21181 If the number of active clients exceeds @code{min-workers}, then more
21182 threads are spawned, up to max_workers limit. Typically you'd want
21183 max_workers to equal maximum number of clients allowed.
21185 Defaults to @samp{20}.
21189 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
21190 Number of priority workers. If all workers from above pool are stuck,
21191 some calls marked as high priority (notably domainDestroy) can be
21192 executed in this pool.
21194 Defaults to @samp{5}.
21198 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
21199 Total global limit on concurrent RPC calls.
21201 Defaults to @samp{20}.
21205 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
21206 Limit on concurrent requests from a single client connection. To avoid
21207 one client monopolizing the server this should be a small fraction of
21208 the global max_requests and max_workers parameter.
21210 Defaults to @samp{5}.
21214 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
21215 Same as @code{min-workers} but for the admin interface.
21217 Defaults to @samp{1}.
21221 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
21222 Same as @code{max-workers} but for the admin interface.
21224 Defaults to @samp{5}.
21228 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
21229 Same as @code{max-clients} but for the admin interface.
21231 Defaults to @samp{5}.
21235 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
21236 Same as @code{max-queued-clients} but for the admin interface.
21238 Defaults to @samp{5}.
21242 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
21243 Same as @code{max-client-requests} but for the admin interface.
21245 Defaults to @samp{5}.
21249 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
21250 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
21252 Defaults to @samp{3}.
21256 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
21259 A filter allows to select a different logging level for a given category
21260 of logs The format for a filter is one of:
21271 where @code{name} is a string which is matched against the category
21272 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
21273 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
21274 be a substring of the full category name, in order to match multiple
21275 similar categories), the optional "+" prefix tells libvirt to log stack
21276 trace for each message matching name, and @code{x} is the minimal level
21277 where matching messages should be logged:
21294 Multiple filters can be defined in a single filters statement, they just
21295 need to be separated by spaces.
21297 Defaults to @samp{"3:remote 4:event"}.
21301 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
21304 An output is one of the places to save logging information The format
21305 for an output can be:
21309 output goes to stderr
21311 @item x:syslog:name
21312 use syslog for the output and use the given name as the ident
21314 @item x:file:file_path
21315 output to a file, with the given filepath
21318 output to journald logging system
21322 In all case the x prefix is the minimal level, acting as a filter
21339 Multiple outputs can be defined, they just need to be separated by
21342 Defaults to @samp{"3:stderr"}.
21346 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
21347 Allows usage of the auditing subsystem to be altered
21351 0: disable all auditing
21354 1: enable auditing, only if enabled on host
21357 2: enable auditing, and exit if disabled on host.
21361 Defaults to @samp{1}.
21365 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
21366 Send audit messages via libvirt logging infrastructure.
21368 Defaults to @samp{#f}.
21372 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
21373 Host UUID. UUID must not have all digits be the same.
21375 Defaults to @samp{""}.
21379 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
21380 Source to read host UUID.
21384 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
21387 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
21391 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
21394 Defaults to @samp{"smbios"}.
21398 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
21399 A keepalive message is sent to a client after @code{keepalive_interval}
21400 seconds of inactivity to check if the client is still responding. If
21401 set to -1, libvirtd will never send keepalive requests; however clients
21402 can still send them and the daemon will send responses.
21404 Defaults to @samp{5}.
21408 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
21409 Maximum number of keepalive messages that are allowed to be sent to the
21410 client without getting any response before the connection is considered
21413 In other words, the connection is automatically closed approximately
21414 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
21415 the last message received from the client. When @code{keepalive-count}
21416 is set to 0, connections will be automatically closed after
21417 @code{keepalive-interval} seconds of inactivity without sending any
21418 keepalive messages.
21420 Defaults to @samp{5}.
21424 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
21425 Same as above but for admin interface.
21427 Defaults to @samp{5}.
21431 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
21432 Same as above but for admin interface.
21434 Defaults to @samp{5}.
21438 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
21439 Timeout for Open vSwitch calls.
21441 The @code{ovs-vsctl} utility is used for the configuration and its
21442 timeout option is set by default to 5 seconds to avoid potential
21443 infinite waits blocking libvirt.
21445 Defaults to @samp{5}.
21449 @c %end of autogenerated docs
21451 @subsubheading Virtlog daemon
21452 The virtlogd service is a server side daemon component of libvirt that is
21453 used to manage logs from virtual machine consoles.
21455 This daemon is not used directly by libvirt client applications, rather it
21456 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
21457 standalone daemon, the main @code{libvirtd} daemon can be restarted without
21458 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
21459 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
21461 @deffn {Scheme Variable} virtlog-service-type
21462 This is the type of the virtlog daemon.
21463 Its value must be a @code{virtlog-configuration}.
21466 (service virtlog-service-type
21467 (virtlog-configuration
21468 (max-clients 1000)))
21472 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
21473 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
21475 Defaults to @samp{3}.
21479 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
21482 A filter allows to select a different logging level for a given category
21483 of logs The format for a filter is one of:
21494 where @code{name} is a string which is matched against the category
21495 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
21496 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
21497 be a substring of the full category name, in order to match multiple
21498 similar categories), the optional "+" prefix tells libvirt to log stack
21499 trace for each message matching name, and @code{x} is the minimal level
21500 where matching messages should be logged:
21517 Multiple filters can be defined in a single filters statement, they just
21518 need to be separated by spaces.
21520 Defaults to @samp{"3:remote 4:event"}.
21524 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
21527 An output is one of the places to save logging information The format
21528 for an output can be:
21532 output goes to stderr
21534 @item x:syslog:name
21535 use syslog for the output and use the given name as the ident
21537 @item x:file:file_path
21538 output to a file, with the given filepath
21541 output to journald logging system
21545 In all case the x prefix is the minimal level, acting as a filter
21562 Multiple outputs can be defined, they just need to be separated by
21565 Defaults to @samp{"3:stderr"}.
21569 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
21570 Maximum number of concurrent client connections to allow over all
21573 Defaults to @samp{1024}.
21577 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
21578 Maximum file size before rolling over.
21580 Defaults to @samp{2MB}
21584 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
21585 Maximum number of backup files to keep.
21587 Defaults to @samp{3}
21591 @subsubheading Transparent Emulation with QEMU
21594 @cindex @code{binfmt_misc}
21595 @code{qemu-binfmt-service-type} provides support for transparent
21596 emulation of program binaries built for different architectures---e.g.,
21597 it allows you to transparently execute an ARMv7 program on an x86_64
21598 machine. It achieves this by combining the @uref{https://www.qemu.org,
21599 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
21601 @defvr {Scheme Variable} qemu-binfmt-service-type
21602 This is the type of the QEMU/binfmt service for transparent emulation.
21603 Its value must be a @code{qemu-binfmt-configuration} object, which
21604 specifies the QEMU package to use as well as the architecture we want to
21608 (service qemu-binfmt-service-type
21609 (qemu-binfmt-configuration
21610 (platforms (lookup-qemu-platforms "arm" "aarch64" "mips64el"))))
21613 In this example, we enable transparent emulation for the ARM and aarch64
21614 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
21615 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
21616 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
21619 @deftp {Data Type} qemu-binfmt-configuration
21620 This is the configuration for the @code{qemu-binfmt} service.
21623 @item @code{platforms} (default: @code{'()})
21624 The list of emulated QEMU platforms. Each item must be a @dfn{platform
21625 object} as returned by @code{lookup-qemu-platforms} (see below).
21627 @item @code{guix-support?} (default: @code{#f})
21628 When it is true, QEMU and all its dependencies are added to the build
21629 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
21630 @code{--chroot-directory} option}). This allows the @code{binfmt_misc}
21631 handlers to be used within the build environment, which in turn means
21632 that you can transparently build programs for another architecture.
21634 For example, let's suppose you're on an x86_64 machine and you have this
21638 (service qemu-binfmt-service-type
21639 (qemu-binfmt-configuration
21640 (platforms (lookup-qemu-platforms "arm"))
21641 (guix-support? #t)))
21647 guix build -s armhf-linux inkscape
21651 and it will build Inkscape for ARMv7 @emph{as if it were a native
21652 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
21653 if you'd like to test a package build for an architecture you don't have
21656 @item @code{qemu} (default: @code{qemu})
21657 The QEMU package to use.
21661 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
21662 Return the list of QEMU platform objects corresponding to
21663 @var{platforms}@dots{}. @var{platforms} must be a list of strings
21664 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
21665 @code{"mips64el"}, and so on.
21668 @deffn {Scheme Procedure} qemu-platform? @var{obj}
21669 Return true if @var{obj} is a platform object.
21672 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
21673 Return the name of @var{platform}---a string such as @code{"arm"}.
21676 @node Version Control Services
21677 @subsection Version Control Services
21679 The @code{(gnu services version-control)} module provides a service to
21680 allow remote access to local Git repositories. There are three options:
21681 the @code{git-daemon-service}, which provides access to repositories via
21682 the @code{git://} unsecured TCP-based protocol, extending the
21683 @code{nginx} web server to proxy some requests to
21684 @code{git-http-backend}, or providing a web interface with
21685 @code{cgit-service-type}.
21687 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
21689 Return a service that runs @command{git daemon}, a simple TCP server to
21690 expose repositories over the Git protocol for anonymous access.
21692 The optional @var{config} argument should be a
21693 @code{<git-daemon-configuration>} object, by default it allows read-only
21694 access to exported@footnote{By creating the magic file
21695 "git-daemon-export-ok" in the repository directory.} repositories under
21700 @deftp {Data Type} git-daemon-configuration
21701 Data type representing the configuration for @code{git-daemon-service}.
21704 @item @code{package} (default: @var{git})
21705 Package object of the Git distributed version control system.
21707 @item @code{export-all?} (default: @var{#f})
21708 Whether to allow access for all Git repositories, even if they do not
21709 have the @file{git-daemon-export-ok} file.
21711 @item @code{base-path} (default: @file{/srv/git})
21712 Whether to remap all the path requests as relative to the given path.
21713 If you run git daemon with @var{(base-path "/srv/git")} on example.com,
21714 then if you later try to pull @code{git://example.com/hello.git}, git
21715 daemon will interpret the path as @code{/srv/git/hello.git}.
21717 @item @code{user-path} (default: @var{#f})
21718 Whether to allow @code{~user} notation to be used in requests. When
21719 specified with empty string, requests to @code{git://host/~alice/foo} is
21720 taken as a request to access @code{foo} repository in the home directory
21721 of user @code{alice}. If @var{(user-path "path")} is specified, the
21722 same request is taken as a request to access @code{path/foo} repository
21723 in the home directory of user @code{alice}.
21725 @item @code{listen} (default: @var{'()})
21726 Whether to listen on specific IP addresses or hostnames, defaults to
21729 @item @code{port} (default: @var{#f})
21730 Whether to listen on an alternative port, which defaults to 9418.
21732 @item @code{whitelist} (default: @var{'()})
21733 If not empty, only allow access to this list of directories.
21735 @item @code{extra-options} (default: @var{'()})
21736 Extra options will be passed to @code{git daemon}, please run
21737 @command{man git-daemon} for more information.
21742 The @code{git://} protocol lacks authentication. When you pull from a
21743 repository fetched via @code{git://}, you don't know that the data you
21744 receive was modified is really coming from the specified host, and you
21745 have your connection is subject to eavesdropping. It's better to use an
21746 authenticated and encrypted transport, such as @code{https}. Although Git allows you
21747 to serve repositories using unsophisticated file-based web servers,
21748 there is a faster protocol implemented by the @code{git-http-backend}
21749 program. This program is the back-end of a proper Git web service. It
21750 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
21751 on running the necessary @code{fcgiwrap} daemon.
21753 Guix has a separate configuration data type for serving Git repositories
21756 @deftp {Data Type} git-http-configuration
21757 Data type representing the configuration for @code{git-http-service}.
21760 @item @code{package} (default: @var{git})
21761 Package object of the Git distributed version control system.
21763 @item @code{git-root} (default: @file{/srv/git})
21764 Directory containing the Git repositories to expose to the world.
21766 @item @code{export-all?} (default: @var{#f})
21767 Whether to expose access for all Git repositories in @var{git-root},
21768 even if they do not have the @file{git-daemon-export-ok} file.
21770 @item @code{uri-path} (default: @file{/git/})
21771 Path prefix for Git access. With the default @code{/git/} prefix, this
21772 will map @code{http://@var{server}/git/@var{repo}.git} to
21773 @code{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
21774 with this prefix are not passed on to this Git instance.
21776 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
21777 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
21782 There is no @code{git-http-service-type}, currently; instead you can
21783 create an @code{nginx-location-configuration} from a
21784 @code{git-http-configuration} and then add that location to a web
21787 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
21788 [config=(git-http-configuration)]
21789 Compute an @code{nginx-location-configuration} that corresponds to the
21790 given Git http configuration. An example nginx service definition to
21791 serve the default @file{/srv/git} over HTTPS might be:
21794 (service nginx-service-type
21795 (nginx-configuration
21798 (nginx-server-configuration
21799 (listen '("443 ssl"))
21800 (server-name "git.my-host.org")
21802 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
21803 (ssl-certificate-key
21804 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
21807 (git-http-nginx-location-configuration
21808 (git-http-configuration (uri-path "/"))))))))))
21811 This example assumes that you are using Let's Encrypt to get your TLS
21812 certificate. @xref{Certificate Services}. The default @code{certbot}
21813 service will redirect all HTTP traffic on @code{git.my-host.org} to
21814 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
21815 system services. @xref{Web Services}.
21818 @subsubheading Cgit Service
21820 @cindex Cgit service
21821 @cindex Git, web interface
21822 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
21823 repositories written in C.
21825 The following example will configure the service with default values.
21826 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
21829 (service cgit-service-type)
21832 The @code{file-object} type designates either a file-like object
21833 (@pxref{G-Expressions, file-like objects}) or a string.
21835 @c %start of fragment
21837 Available @code{cgit-configuration} fields are:
21839 @deftypevr {@code{cgit-configuration} parameter} package package
21844 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
21845 NGINX configuration.
21849 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
21850 Specifies a command which will be invoked to format the content of about
21851 pages (both top-level and for each repository).
21853 Defaults to @samp{""}.
21857 @deftypevr {@code{cgit-configuration} parameter} string agefile
21858 Specifies a path, relative to each repository path, which can be used to
21859 specify the date and time of the youngest commit in the repository.
21861 Defaults to @samp{""}.
21865 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
21866 Specifies a command that will be invoked for authenticating repository
21869 Defaults to @samp{""}.
21873 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
21874 Flag which, when set to @samp{age}, enables date ordering in the branch
21875 ref list, and when set @samp{name} enables ordering by branch name.
21877 Defaults to @samp{"name"}.
21881 @deftypevr {@code{cgit-configuration} parameter} string cache-root
21882 Path used to store the cgit cache entries.
21884 Defaults to @samp{"/var/cache/cgit"}.
21888 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
21889 Number which specifies the time-to-live, in minutes, for the cached
21890 version of repository pages accessed with a fixed SHA1.
21892 Defaults to @samp{-1}.
21896 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
21897 Number which specifies the time-to-live, in minutes, for the cached
21898 version of repository pages accessed without a fixed SHA1.
21900 Defaults to @samp{5}.
21904 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
21905 Number which specifies the time-to-live, in minutes, for the cached
21906 version of the repository summary page.
21908 Defaults to @samp{5}.
21912 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
21913 Number which specifies the time-to-live, in minutes, for the cached
21914 version of the repository index page.
21916 Defaults to @samp{5}.
21920 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
21921 Number which specifies the time-to-live, in minutes, for the result of
21922 scanning a path for Git repositories.
21924 Defaults to @samp{15}.
21928 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
21929 Number which specifies the time-to-live, in minutes, for the cached
21930 version of the repository about page.
21932 Defaults to @samp{15}.
21936 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
21937 Number which specifies the time-to-live, in minutes, for the cached
21938 version of snapshots.
21940 Defaults to @samp{5}.
21944 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
21945 The maximum number of entries in the cgit cache. When set to @samp{0},
21946 caching is disabled.
21948 Defaults to @samp{0}.
21952 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
21953 Sort items in the repo list case sensitively.
21955 Defaults to @samp{#t}.
21959 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
21960 List of common prefixes which, when combined with a repository URL,
21961 generates valid clone URLs for the repository.
21963 Defaults to @samp{()}.
21967 @deftypevr {@code{cgit-configuration} parameter} list clone-url
21968 List of @code{clone-url} templates.
21970 Defaults to @samp{()}.
21974 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
21975 Command which will be invoked to format commit messages.
21977 Defaults to @samp{""}.
21981 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
21982 Flag which, when set to @samp{date}, enables strict date ordering in the
21983 commit log, and when set to @samp{topo} enables strict topological
21986 Defaults to @samp{"git log"}.
21990 @deftypevr {@code{cgit-configuration} parameter} file-object css
21991 URL which specifies the css document to include in all cgit pages.
21993 Defaults to @samp{"/share/cgit/cgit.css"}.
21997 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
21998 Specifies a command which will be invoked to format names and email
21999 address of committers, authors, and taggers, as represented in various
22000 places throughout the cgit interface.
22002 Defaults to @samp{""}.
22006 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
22007 Flag which, when set to @samp{#t}, will make cgit generate a HTML
22008 fragment suitable for embedding in other HTML pages.
22010 Defaults to @samp{#f}.
22014 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
22015 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
22016 commit history graph to the left of the commit messages in the
22017 repository log page.
22019 Defaults to @samp{#f}.
22023 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
22024 Flag which, when set to @samp{#t}, allows all filter settings to be
22025 overridden in repository-specific cgitrc files.
22027 Defaults to @samp{#f}.
22031 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
22032 Flag which, when set to @samp{#t}, allows users to follow a file in the
22035 Defaults to @samp{#f}.
22039 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
22040 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
22043 Defaults to @samp{#t}.
22047 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
22048 Flag which, when set to @samp{#t}, will make cgit generate extra links
22049 "summary", "commit", "tree" for each repo in the repository index.
22051 Defaults to @samp{#f}.
22055 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
22056 Flag which, when set to @samp{#t}, will make cgit display the owner of
22057 each repo in the repository index.
22059 Defaults to @samp{#t}.
22063 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
22064 Flag which, when set to @samp{#t}, will make cgit print the number of
22065 modified files for each commit on the repository log page.
22067 Defaults to @samp{#f}.
22071 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
22072 Flag which, when set to @samp{#t}, will make cgit print the number of
22073 added and removed lines for each commit on the repository log page.
22075 Defaults to @samp{#f}.
22079 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
22080 Flag which, when set to @code{#t}, will make cgit display remote
22081 branches in the summary and refs views.
22083 Defaults to @samp{#f}.
22087 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
22088 Flag which, when set to @code{1}, will make cgit use the subject of the
22089 parent commit as link text when generating links to parent commits in
22092 Defaults to @samp{#f}.
22096 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
22097 Flag which, when set to @samp{#t}, will make cgit use the subject of the
22098 parent commit as link text when generating links to parent commits in
22101 Defaults to @samp{#f}.
22105 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
22106 Flag which, when set to @samp{#t}, will make cgit generate linenumber
22107 links for plaintext blobs printed in the tree view.
22109 Defaults to @samp{#t}.
22113 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
22114 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
22115 set any repo specific settings.
22117 Defaults to @samp{#f}.
22121 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
22122 URL used as link to a shortcut icon for cgit.
22124 Defaults to @samp{"/favicon.ico"}.
22128 @deftypevr {@code{cgit-configuration} parameter} string footer
22129 The content of the file specified with this option will be included
22130 verbatim at the bottom of all pages (i.e.@: it replaces the standard
22131 "generated by..."@: message).
22133 Defaults to @samp{""}.
22137 @deftypevr {@code{cgit-configuration} parameter} string head-include
22138 The content of the file specified with this option will be included
22139 verbatim in the HTML HEAD section on all pages.
22141 Defaults to @samp{""}.
22145 @deftypevr {@code{cgit-configuration} parameter} string header
22146 The content of the file specified with this option will be included
22147 verbatim at the top of all pages.
22149 Defaults to @samp{""}.
22153 @deftypevr {@code{cgit-configuration} parameter} file-object include
22154 Name of a configfile to include before the rest of the current config-
22157 Defaults to @samp{""}.
22161 @deftypevr {@code{cgit-configuration} parameter} string index-header
22162 The content of the file specified with this option will be included
22163 verbatim above the repository index.
22165 Defaults to @samp{""}.
22169 @deftypevr {@code{cgit-configuration} parameter} string index-info
22170 The content of the file specified with this option will be included
22171 verbatim below the heading on the repository index page.
22173 Defaults to @samp{""}.
22177 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
22178 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
22179 in the servers timezone.
22181 Defaults to @samp{#f}.
22185 @deftypevr {@code{cgit-configuration} parameter} file-object logo
22186 URL which specifies the source of an image which will be used as a logo
22189 Defaults to @samp{"/share/cgit/cgit.png"}.
22193 @deftypevr {@code{cgit-configuration} parameter} string logo-link
22194 URL loaded when clicking on the cgit logo image.
22196 Defaults to @samp{""}.
22200 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
22201 Command which will be invoked to format the Owner column of the main
22204 Defaults to @samp{""}.
22208 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
22209 Number of items to display in atom feeds view.
22211 Defaults to @samp{10}.
22215 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
22216 Number of entries to list per page in "log" view.
22218 Defaults to @samp{50}.
22222 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
22223 Number of commit message characters to display in "log" view.
22225 Defaults to @samp{80}.
22229 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
22230 Specifies the number of entries to list per page on the repository index
22233 Defaults to @samp{50}.
22237 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
22238 Specifies the maximum number of repo description characters to display
22239 on the repository index page.
22241 Defaults to @samp{80}.
22245 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
22246 Specifies the maximum size of a blob to display HTML for in KBytes.
22248 Defaults to @samp{0}.
22252 @deftypevr {@code{cgit-configuration} parameter} string max-stats
22253 Maximum statistics period. Valid values are @samp{week},@samp{month},
22254 @samp{quarter} and @samp{year}.
22256 Defaults to @samp{""}.
22260 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
22261 Mimetype for the specified filename extension.
22263 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
22264 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
22265 "image/png") (svg "image/svg+xml"))}.
22269 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
22270 Specifies the file to use for automatic mimetype lookup.
22272 Defaults to @samp{""}.
22276 @deftypevr {@code{cgit-configuration} parameter} string module-link
22277 Text which will be used as the formatstring for a hyperlink when a
22278 submodule is printed in a directory listing.
22280 Defaults to @samp{""}.
22284 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
22285 If set to the value @samp{#t} caching will be disabled.
22287 Defaults to @samp{#f}.
22291 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
22292 If set to @samp{#t} showing full author email addresses will be
22295 Defaults to @samp{#f}.
22299 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
22300 Flag which, when set to @samp{#t}, will make cgit omit the standard
22301 header on all pages.
22303 Defaults to @samp{#f}.
22307 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
22308 A list of subdirectories inside of @code{repository-directory}, relative
22309 to it, that should loaded as Git repositories. An empty list means that
22310 all subdirectories will be loaded.
22312 Defaults to @samp{()}.
22316 @deftypevr {@code{cgit-configuration} parameter} file-object readme
22317 Text which will be used as default value for @code{cgit-repo-readme}.
22319 Defaults to @samp{""}.
22323 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
22324 If set to @code{#t} and @code{repository-directory} is enabled, if any
22325 repositories are found with a suffix of @code{.git}, this suffix will be
22326 removed for the URL and name.
22328 Defaults to @samp{#f}.
22332 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
22333 Maximum number of files to consider when detecting renames.
22335 Defaults to @samp{-1}.
22339 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
22340 The way in which repositories in each section are sorted.
22342 Defaults to @samp{""}.
22346 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
22347 Text used as content for the @code{robots} meta-tag.
22349 Defaults to @samp{("noindex" "nofollow")}.
22353 @deftypevr {@code{cgit-configuration} parameter} string root-desc
22354 Text printed below the heading on the repository index page.
22356 Defaults to @samp{"a fast webinterface for the git dscm"}.
22360 @deftypevr {@code{cgit-configuration} parameter} string root-readme
22361 The content of the file specified with this option will be included
22362 verbatim below thef "about" link on the repository index page.
22364 Defaults to @samp{""}.
22368 @deftypevr {@code{cgit-configuration} parameter} string root-title
22369 Text printed as heading on the repository index page.
22371 Defaults to @samp{""}.
22375 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
22376 If set to @samp{#t} and repository-directory is enabled,
22377 repository-directory will recurse into directories whose name starts
22378 with a period. Otherwise, repository-directory will stay away from such
22379 directories, considered as "hidden". Note that this does not apply to
22380 the ".git" directory in non-bare repos.
22382 Defaults to @samp{#f}.
22386 @deftypevr {@code{cgit-configuration} parameter} list snapshots
22387 Text which specifies the default set of snapshot formats that cgit
22388 generates links for.
22390 Defaults to @samp{()}.
22394 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
22395 Name of the directory to scan for repositories (represents
22398 Defaults to @samp{"/srv/git"}.
22402 @deftypevr {@code{cgit-configuration} parameter} string section
22403 The name of the current repository section - all repositories defined
22404 after this option will inherit the current section name.
22406 Defaults to @samp{""}.
22410 @deftypevr {@code{cgit-configuration} parameter} string section-sort
22411 Flag which, when set to @samp{1}, will sort the sections on the
22412 repository listing by name.
22414 Defaults to @samp{""}.
22418 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
22419 A number which, if defined prior to repository-directory, specifies how
22420 many path elements from each repo path to use as a default section name.
22422 Defaults to @samp{0}.
22426 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
22427 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
22430 Defaults to @samp{#f}.
22434 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
22435 Specifies a command which will be invoked to format plaintext blobs in
22438 Defaults to @samp{""}.
22442 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
22443 Specifies the number of branches to display in the repository "summary"
22446 Defaults to @samp{10}.
22450 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
22451 Specifies the number of log entries to display in the repository
22454 Defaults to @samp{10}.
22458 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
22459 Specifies the number of tags to display in the repository "summary"
22462 Defaults to @samp{10}.
22466 @deftypevr {@code{cgit-configuration} parameter} string strict-export
22467 Filename which, if specified, needs to be present within the repository
22468 for cgit to allow access to that repository.
22470 Defaults to @samp{""}.
22474 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
22475 URL which, if specified, will be used as root for all cgit links.
22477 Defaults to @samp{"/"}.
22481 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
22482 A list of @dfn{cgit-repo} records to use with config.
22484 Defaults to @samp{()}.
22486 Available @code{repository-cgit-configuration} fields are:
22488 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
22489 A mask of snapshot formats for this repo that cgit generates links for,
22490 restricted by the global @code{snapshots} setting.
22492 Defaults to @samp{()}.
22496 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
22497 Override the default @code{source-filter}.
22499 Defaults to @samp{""}.
22503 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
22504 The relative URL used to access the repository.
22506 Defaults to @samp{""}.
22510 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
22511 Override the default @code{about-filter}.
22513 Defaults to @samp{""}.
22517 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
22518 Flag which, when set to @samp{age}, enables date ordering in the branch
22519 ref list, and when set to @samp{name} enables ordering by branch name.
22521 Defaults to @samp{""}.
22525 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
22526 A list of URLs which can be used to clone repo.
22528 Defaults to @samp{()}.
22532 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
22533 Override the default @code{commit-filter}.
22535 Defaults to @samp{""}.
22539 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
22540 Flag which, when set to @samp{date}, enables strict date ordering in the
22541 commit log, and when set to @samp{topo} enables strict topological
22544 Defaults to @samp{""}.
22548 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
22549 The name of the default branch for this repository. If no such branch
22550 exists in the repository, the first branch name (when sorted) is used as
22551 default instead. By default branch pointed to by HEAD, or "master" if
22552 there is no suitable HEAD.
22554 Defaults to @samp{""}.
22558 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
22559 The value to show as repository description.
22561 Defaults to @samp{""}.
22565 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
22566 The value to show as repository homepage.
22568 Defaults to @samp{""}.
22572 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
22573 Override the default @code{email-filter}.
22575 Defaults to @samp{""}.
22579 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
22580 A flag which can be used to disable the global setting
22581 @code{enable-commit-graph?}.
22583 Defaults to @samp{disabled}.
22587 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
22588 A flag which can be used to disable the global setting
22589 @code{enable-log-filecount?}.
22591 Defaults to @samp{disabled}.
22595 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
22596 A flag which can be used to disable the global setting
22597 @code{enable-log-linecount?}.
22599 Defaults to @samp{disabled}.
22603 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
22604 Flag which, when set to @code{#t}, will make cgit display remote
22605 branches in the summary and refs views.
22607 Defaults to @samp{disabled}.
22611 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
22612 A flag which can be used to override the global setting
22613 @code{enable-subject-links?}.
22615 Defaults to @samp{disabled}.
22619 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
22620 A flag which can be used to override the global setting
22621 @code{enable-html-serving?}.
22623 Defaults to @samp{disabled}.
22627 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
22628 Flag which, when set to @code{#t}, hides the repository from the
22631 Defaults to @samp{#f}.
22635 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
22636 Flag which, when set to @samp{#t}, ignores the repository.
22638 Defaults to @samp{#f}.
22642 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
22643 URL which specifies the source of an image which will be used as a logo
22644 on this repo’s pages.
22646 Defaults to @samp{""}.
22650 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
22651 URL loaded when clicking on the cgit logo image.
22653 Defaults to @samp{""}.
22657 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
22658 Override the default @code{owner-filter}.
22660 Defaults to @samp{""}.
22664 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
22665 Text which will be used as the formatstring for a hyperlink when a
22666 submodule is printed in a directory listing. The arguments for the
22667 formatstring are the path and SHA1 of the submodule commit.
22669 Defaults to @samp{""}.
22673 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
22674 Text which will be used as the formatstring for a hyperlink when a
22675 submodule with the specified subdirectory path is printed in a directory
22678 Defaults to @samp{()}.
22682 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
22683 Override the default maximum statistics period.
22685 Defaults to @samp{""}.
22689 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
22690 The value to show as repository name.
22692 Defaults to @samp{""}.
22696 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
22697 A value used to identify the owner of the repository.
22699 Defaults to @samp{""}.
22703 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
22704 An absolute path to the repository directory.
22706 Defaults to @samp{""}.
22710 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
22711 A path (relative to repo) which specifies a file to include verbatim as
22712 the "About" page for this repo.
22714 Defaults to @samp{""}.
22718 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
22719 The name of the current repository section - all repositories defined
22720 after this option will inherit the current section name.
22722 Defaults to @samp{""}.
22726 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
22727 Extra options will be appended to cgitrc file.
22729 Defaults to @samp{()}.
22735 @deftypevr {@code{cgit-configuration} parameter} list extra-options
22736 Extra options will be appended to cgitrc file.
22738 Defaults to @samp{()}.
22743 @c %end of fragment
22745 However, it could be that you just want to get a @code{cgitrc} up and
22746 running. In that case, you can pass an @code{opaque-cgit-configuration}
22747 as a record to @code{cgit-service-type}. As its name indicates, an
22748 opaque configuration does not have easy reflective capabilities.
22750 Available @code{opaque-cgit-configuration} fields are:
22752 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
22756 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
22757 The contents of the @code{cgitrc}, as a string.
22760 For example, if your @code{cgitrc} is just the empty string, you
22761 could instantiate a cgit service like this:
22764 (service cgit-service-type
22765 (opaque-cgit-configuration
22769 @subsubheading Gitolite Service
22771 @cindex Gitolite service
22772 @cindex Git, hosting
22773 @uref{http://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
22774 repositories on a central server.
22776 Gitolite can handle multiple repositories and users, and supports flexible
22777 configuration of the permissions for the users on the repositories.
22779 The following example will configure Gitolite using the default @code{git}
22780 user, and the provided SSH public key.
22783 (service gitolite-service-type
22784 (gitolite-configuration
22785 (admin-pubkey (plain-file
22787 "ssh-rsa AAAA... guix@@example.com"))))
22790 Gitolite is configured through a special admin repository which you can clone,
22791 for example, if you setup Gitolite on @code{example.com}, you would run the
22792 following command to clone the admin repository.
22795 git clone git@@example.com:gitolite-admin
22798 When the Gitolite service is activated, the provided @code{admin-pubkey} will
22799 be inserted in to the @file{keydir} directory in the gitolite-admin
22800 repository. If this results in a change in the repository, it will be
22801 committed using the message ``gitolite setup by GNU Guix''.
22803 @deftp {Data Type} gitolite-configuration
22804 Data type representing the configuration for @code{gitolite-service-type}.
22807 @item @code{package} (default: @var{gitolite})
22808 Gitolite package to use.
22810 @item @code{user} (default: @var{git})
22811 User to use for Gitolite. This will be user that you use when accessing
22814 @item @code{group} (default: @var{git})
22815 Group to use for Gitolite.
22817 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
22818 Directory in which to store the Gitolite configuration and repositories.
22820 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
22821 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
22822 representing the configuration for Gitolite.
22824 @item @code{admin-pubkey} (default: @var{#f})
22825 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
22826 setup Gitolite. This will be inserted in to the @file{keydir} directory
22827 within the gitolite-admin repository.
22829 To specify the SSH key as a string, use the @code{plain-file} function.
22832 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
22838 @deftp {Data Type} gitolite-rc-file
22839 Data type representing the Gitolite RC file.
22842 @item @code{umask} (default: @code{#o0077})
22843 This controls the permissions Gitolite sets on the repositories and their
22846 A value like @code{#o0027} will give read access to the group used by Gitolite
22847 (by default: @code{git}). This is necessary when using Gitolite with software
22848 like cgit or gitweb.
22850 @item @code{git-config-keys} (default: @code{""})
22851 Gitolite allows you to set git config values using the "config" keyword. This
22852 setting allows control over the config keys to accept.
22854 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
22855 Set the role names allowed to be used by users running the perms command.
22857 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
22858 This setting controls the commands and features to enable within Gitolite.
22864 @node Game Services
22865 @subsection Game Services
22867 @subsubheading The Battle for Wesnoth Service
22869 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
22870 based tactical strategy game, with several single player campaigns, and
22871 multiplayer games (both networked and local).
22873 @defvar {Scheme Variable} wesnothd-service-type
22874 Service type for the wesnothd service. Its value must be a
22875 @code{wesnothd-configuration} object. To run wesnothd in the default
22876 configuration, instantiate it as:
22879 (service wesnothd-service-type)
22883 @deftp {Data Type} wesnothd-configuration
22884 Data type representing the configuration of @command{wesnothd}.
22887 @item @code{package} (default: @code{wesnoth-server})
22888 The wesnoth server package to use.
22890 @item @code{port} (default: @code{15000})
22891 The port to bind the server to.
22895 @node Miscellaneous Services
22896 @subsection Miscellaneous Services
22898 @cindex fingerprint
22899 @subsubheading Fingerprint Service
22901 The @code{(gnu services fingerprint)} module provides a DBus service to
22902 read and identify fingerprints via a fingerprint sensor.
22904 @defvr {Scheme Variable} fprintd-service-type
22905 The service type for @command{fprintd}, which provides the fingerprint
22906 reading capability.
22909 (service fprintd-service-type)
22914 @subsubheading System Control Service
22916 The @code{(gnu services sysctl)} provides a service to configure kernel
22917 parameters at boot.
22919 @defvr {Scheme Variable} sysctl-service-type
22920 The service type for @command{sysctl}, which modifies kernel parameters
22921 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
22925 (service sysctl-service-type
22926 (sysctl-configuration
22927 (settings '(("net.ipv4.ip_forward" . "1")))))
22931 @deftp {Data Type} sysctl-configuration
22932 The data type representing the configuration of @command{sysctl}.
22935 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
22936 The @command{sysctl} executable to use.
22938 @item @code{settings} (default: @code{'()})
22939 An association list specifies kernel parameters and their values.
22944 @subsubheading PC/SC Smart Card Daemon Service
22946 The @code{(gnu services security-token)} module provides the following service
22947 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
22948 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
22949 manager that coordinates communications with smart card readers, smart cards
22950 and cryptographic tokens that are connected to the system.
22952 @defvr {Scheme Variable} pcscd-service-type
22953 Service type for the @command{pcscd} service. Its value must be a
22954 @code{pcscd-configuration} object. To run pcscd in the default
22955 configuration, instantiate it as:
22958 (service pcscd-service-type)
22962 @deftp {Data Type} pcscd-configuration
22963 The data type representing the configuration of @command{pcscd}.
22966 @item @code{pcsc-lite} (default: @code{pcsc-lite})
22967 The pcsc-lite package that provides pcscd.
22968 @item @code{usb-drivers} (default: @code{(list ccid)})
22969 List of packages that provide USB drivers to pcscd. Drivers are expected to be
22970 under @file{pcsc/drivers} in the store directory of the package.
22975 @subsubheading Lirc Service
22977 The @code{(gnu services lirc)} module provides the following service.
22979 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
22980 [#:device #f] [#:driver #f] [#:config-file #f] @
22981 [#:extra-options '()]
22982 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
22983 decodes infrared signals from remote controls.
22985 Optionally, @var{device}, @var{driver} and @var{config-file}
22986 (configuration file name) may be specified. See @command{lircd} manual
22989 Finally, @var{extra-options} is a list of additional command-line options
22990 passed to @command{lircd}.
22994 @subsubheading Spice Service
22996 The @code{(gnu services spice)} module provides the following service.
22998 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
22999 Returns a service that runs @url{http://www.spice-space.org,VDAGENT}, a daemon
23000 that enables sharing the clipboard with a vm and setting the guest display
23001 resolution when the graphical console window resizes.
23004 @cindex inputattach
23005 @subsubheading inputattach Service
23007 @cindex tablet input, for Xorg
23008 @cindex touchscreen input, for Xorg
23009 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
23010 use input devices such as Wacom tablets, touchscreens, or joysticks with the
23011 Xorg display server.
23013 @deffn {Scheme Variable} inputattach-service-type
23014 Type of a service that runs @command{inputattach} on a device and
23015 dispatches events from it.
23018 @deftp {Data Type} inputattach-configuration
23020 @item @code{device-type} (default: @code{"wacom"})
23021 The type of device to connect to. Run @command{inputattach --help}, from the
23022 @code{inputattach} package, to see the list of supported device types.
23024 @item @code{device} (default: @code{"/dev/ttyS0"})
23025 The device file to connect to the device.
23027 @item @code{log-file} (default: @code{#f})
23028 If true, this must be the name of a file to log messages to.
23032 @subsection Dictionary Services
23034 The @code{(gnu services dict)} module provides the following service:
23036 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
23037 Return a service that runs the @command{dicod} daemon, an implementation
23038 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
23040 The optional @var{config} argument specifies the configuration for
23041 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
23042 default it serves the GNU Collaborative International Dictonary of English.
23044 You can add @command{open localhost} to your @file{~/.dico} file to make
23045 @code{localhost} the default server for @command{dico} client
23046 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
23049 @deftp {Data Type} dicod-configuration
23050 Data type representing the configuration of dicod.
23053 @item @code{dico} (default: @var{dico})
23054 Package object of the GNU Dico dictionary server.
23056 @item @code{interfaces} (default: @var{'("localhost")})
23057 This is the list of IP addresses and ports and possibly socket file
23058 names to listen to (@pxref{Server Settings, @code{listen} directive,,
23059 dico, GNU Dico Manual}).
23061 @item @code{handlers} (default: @var{'()})
23062 List of @code{<dicod-handler>} objects denoting handlers (module instances).
23064 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
23065 List of @code{<dicod-database>} objects denoting dictionaries to be served.
23069 @deftp {Data Type} dicod-handler
23070 Data type representing a dictionary handler (module instance).
23074 Name of the handler (module instance).
23076 @item @code{module} (default: @var{#f})
23077 Name of the dicod module of the handler (instance). If it is @code{#f},
23078 the module has the same name as the handler.
23079 (@pxref{Modules,,, dico, GNU Dico Manual}).
23081 @item @code{options}
23082 List of strings or gexps representing the arguments for the module handler
23086 @deftp {Data Type} dicod-database
23087 Data type representing a dictionary database.
23091 Name of the database, will be used in DICT commands.
23093 @item @code{handler}
23094 Name of the dicod handler (module instance) used by this database
23095 (@pxref{Handlers,,, dico, GNU Dico Manual}).
23097 @item @code{complex?} (default: @var{#f})
23098 Whether the database configuration complex. The complex configuration
23099 will need a corresponding @code{<dicod-handler>} object, otherwise not.
23101 @item @code{options}
23102 List of strings or gexps representing the arguments for the database
23103 (@pxref{Databases,,, dico, GNU Dico Manual}).
23107 @defvr {Scheme Variable} %dicod-database:gcide
23108 A @code{<dicod-database>} object serving the GNU Collaborative International
23109 Dictionary of English using the @code{gcide} package.
23112 The following is an example @code{dicod-service} configuration.
23115 (dicod-service #:config
23116 (dicod-configuration
23117 (handlers (list (dicod-handler
23121 (list #~(string-append "dbdir=" #$wordnet))))))
23122 (databases (list (dicod-database
23125 (handler "wordnet")
23126 (options '("database=wn")))
23127 %dicod-database:gcide))))
23131 @subsubheading Docker Service
23133 The @code{(gnu services docker)} module provides the following service.
23135 @defvr {Scheme Variable} docker-service-type
23137 This is the type of the service that runs @url{http://www.docker.com,Docker},
23138 a daemon that can execute application bundles (sometimes referred to as
23139 ``containers'') in isolated environments.
23143 @deftp {Data Type} docker-configuration
23144 This is the data type representing the configuration of Docker and Containerd.
23148 @item @code{package} (default: @code{docker})
23149 The Docker package to use.
23151 @item @code{containerd} (default: @var{containerd})
23152 The Containerd package to use.
23157 @node Setuid Programs
23158 @section Setuid Programs
23160 @cindex setuid programs
23161 Some programs need to run with ``root'' privileges, even when they are
23162 launched by unprivileged users. A notorious example is the
23163 @command{passwd} program, which users can run to change their
23164 password, and which needs to access the @file{/etc/passwd} and
23165 @file{/etc/shadow} files---something normally restricted to root, for
23166 obvious security reasons. To address that, these executables are
23167 @dfn{setuid-root}, meaning that they always run with root privileges
23168 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
23169 for more info about the setuid mechanism.)
23171 The store itself @emph{cannot} contain setuid programs: that would be a
23172 security issue since any user on the system can write derivations that
23173 populate the store (@pxref{The Store}). Thus, a different mechanism is
23174 used: instead of changing the setuid bit directly on files that are in
23175 the store, we let the system administrator @emph{declare} which programs
23176 should be setuid root.
23178 The @code{setuid-programs} field of an @code{operating-system}
23179 declaration contains a list of G-expressions denoting the names of
23180 programs to be setuid-root (@pxref{Using the Configuration System}).
23181 For instance, the @command{passwd} program, which is part of the Shadow
23182 package, can be designated by this G-expression (@pxref{G-Expressions}):
23185 #~(string-append #$shadow "/bin/passwd")
23188 A default set of setuid programs is defined by the
23189 @code{%setuid-programs} variable of the @code{(gnu system)} module.
23191 @defvr {Scheme Variable} %setuid-programs
23192 A list of G-expressions denoting common programs that are setuid-root.
23194 The list includes commands such as @command{passwd}, @command{ping},
23195 @command{su}, and @command{sudo}.
23198 Under the hood, the actual setuid programs are created in the
23199 @file{/run/setuid-programs} directory at system activation time. The
23200 files in this directory refer to the ``real'' binaries, which are in the
23203 @node X.509 Certificates
23204 @section X.509 Certificates
23206 @cindex HTTPS, certificates
23207 @cindex X.509 certificates
23209 Web servers available over HTTPS (that is, HTTP over the transport-layer
23210 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
23211 that the client can then use to @emph{authenticate} the server. To do
23212 that, clients verify that the server's certificate is signed by a
23213 so-called @dfn{certificate authority} (CA). But to verify the CA's
23214 signature, clients must have first acquired the CA's certificate.
23216 Web browsers such as GNU@tie{}IceCat include their own set of CA
23217 certificates, such that they are able to verify CA signatures
23220 However, most other programs that can talk HTTPS---@command{wget},
23221 @command{git}, @command{w3m}, etc.---need to be told where CA
23222 certificates can be found.
23224 @cindex @code{nss-certs}
23225 In Guix, this is done by adding a package that provides certificates
23226 to the @code{packages} field of the @code{operating-system} declaration
23227 (@pxref{operating-system Reference}). Guix includes one such package,
23228 @code{nss-certs}, which is a set of CA certificates provided as part of
23229 Mozilla's Network Security Services.
23231 Note that it is @emph{not} part of @var{%base-packages}, so you need to
23232 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
23233 most applications and libraries look for certificates by default, points
23234 to the certificates installed globally.
23236 Unprivileged users, including users of Guix on a foreign distro,
23237 can also install their own certificate package in
23238 their profile. A number of environment variables need to be defined so
23239 that applications and libraries know where to find them. Namely, the
23240 OpenSSL library honors the @code{SSL_CERT_DIR} and @code{SSL_CERT_FILE}
23241 variables. Some applications add their own environment variables; for
23242 instance, the Git version control system honors the certificate bundle
23243 pointed to by the @code{GIT_SSL_CAINFO} environment variable. Thus, you
23244 would typically run something like:
23247 $ guix package -i nss-certs
23248 $ export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
23249 $ export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
23250 $ export GIT_SSL_CAINFO="$SSL_CERT_FILE"
23253 As another example, R requires the @code{CURL_CA_BUNDLE} environment
23254 variable to point to a certificate bundle, so you would have to run
23255 something like this:
23258 $ guix package -i nss-certs
23259 $ export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
23262 For other applications you may want to look up the required environment
23263 variable in the relevant documentation.
23266 @node Name Service Switch
23267 @section Name Service Switch
23269 @cindex name service switch
23271 The @code{(gnu system nss)} module provides bindings to the
23272 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
23273 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
23274 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
23275 extended with new ``name'' lookup methods for system databases, which
23276 includes host names, service names, user accounts, and more (@pxref{Name
23277 Service Switch, System Databases and Name Service Switch,, libc, The GNU
23278 C Library Reference Manual}).
23280 The NSS configuration specifies, for each system database, which lookup
23281 method is to be used, and how the various methods are chained
23282 together---for instance, under which circumstances NSS should try the
23283 next method in the list. The NSS configuration is given in the
23284 @code{name-service-switch} field of @code{operating-system} declarations
23285 (@pxref{operating-system Reference, @code{name-service-switch}}).
23288 @cindex .local, host name lookup
23289 As an example, the declaration below configures the NSS to use the
23290 @uref{http://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
23291 back-end}, which supports host name lookups over multicast DNS (mDNS)
23292 for host names ending in @code{.local}:
23295 (name-service-switch
23296 (hosts (list %files ;first, check /etc/hosts
23298 ;; If the above did not succeed, try
23299 ;; with 'mdns_minimal'.
23301 (name "mdns_minimal")
23303 ;; 'mdns_minimal' is authoritative for
23304 ;; '.local'. When it returns "not found",
23305 ;; no need to try the next methods.
23306 (reaction (lookup-specification
23307 (not-found => return))))
23309 ;; Then fall back to DNS.
23313 ;; Finally, try with the "full" 'mdns'.
23318 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
23319 contains this configuration, so you will not have to type it if all you
23320 want is to have @code{.local} host lookup working.
23322 Note that, in this case, in addition to setting the
23323 @code{name-service-switch} of the @code{operating-system} declaration,
23324 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
23325 @code{avahi-service-type}}), or @var{%desktop-services}, which includes it
23326 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
23327 to the name service cache daemon (@pxref{Base Services,
23328 @code{nscd-service}}).
23330 For convenience, the following variables provide typical NSS
23333 @defvr {Scheme Variable} %default-nss
23334 This is the default name service switch configuration, a
23335 @code{name-service-switch} object.
23338 @defvr {Scheme Variable} %mdns-host-lookup-nss
23339 This is the name service switch configuration with support for host name
23340 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
23343 The reference for name service switch configuration is given below. It
23344 is a direct mapping of the configuration file format of the C library , so
23345 please refer to the C library manual for more information (@pxref{NSS
23346 Configuration File,,, libc, The GNU C Library Reference Manual}).
23347 Compared to the configuration file format of libc NSS, it has the advantage
23348 not only of adding this warm parenthetic feel that we like, but also
23349 static checks: you will know about syntax errors and typos as soon as you
23350 run @command{guix system}.
23352 @deftp {Data Type} name-service-switch
23354 This is the data type representation the configuration of libc's name
23355 service switch (NSS). Each field below represents one of the supported
23372 The system databases handled by the NSS. Each of these fields must be a
23373 list of @code{<name-service>} objects (see below).
23377 @deftp {Data Type} name-service
23379 This is the data type representing an actual name service and the
23380 associated lookup action.
23384 A string denoting the name service (@pxref{Services in the NSS
23385 configuration,,, libc, The GNU C Library Reference Manual}).
23387 Note that name services listed here must be visible to nscd. This is
23388 achieved by passing the @code{#:name-services} argument to
23389 @code{nscd-service} the list of packages providing the needed name
23390 services (@pxref{Base Services, @code{nscd-service}}).
23393 An action specified using the @code{lookup-specification} macro
23394 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
23395 Reference Manual}). For example:
23398 (lookup-specification (unavailable => continue)
23399 (success => return))
23404 @node Initial RAM Disk
23405 @section Initial RAM Disk
23408 @cindex initial RAM disk
23409 For bootstrapping purposes, the Linux-Libre kernel is passed an
23410 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
23411 root file system as well as an initialization script. The latter is
23412 responsible for mounting the real root file system, and for loading any
23413 kernel modules that may be needed to achieve that.
23415 The @code{initrd-modules} field of an @code{operating-system}
23416 declaration allows you to specify Linux-libre kernel modules that must
23417 be available in the initrd. In particular, this is where you would list
23418 modules needed to actually drive the hard disk where your root partition
23419 is---although the default value of @code{initrd-modules} should cover
23420 most use cases. For example, assuming you need the @code{megaraid_sas}
23421 module in addition to the default modules to be able to access your root
23422 file system, you would write:
23427 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
23430 @defvr {Scheme Variable} %base-initrd-modules
23431 This is the list of kernel modules included in the initrd by default.
23434 Furthermore, if you need lower-level customization, the @code{initrd}
23435 field of an @code{operating-system} declaration allows
23436 you to specify which initrd you would like to use. The @code{(gnu
23437 system linux-initrd)} module provides three ways to build an initrd: the
23438 high-level @code{base-initrd} procedure and the low-level
23439 @code{raw-initrd} and @code{expression->initrd} procedures.
23441 The @code{base-initrd} procedure is intended to cover most common uses.
23442 For example, if you want to add a bunch of kernel modules to be loaded
23443 at boot time, you can define the @code{initrd} field of the operating
23444 system declaration like this:
23447 (initrd (lambda (file-systems . rest)
23448 ;; Create a standard initrd but set up networking
23449 ;; with the parameters QEMU expects by default.
23450 (apply base-initrd file-systems
23451 #:qemu-networking? #t
23455 The @code{base-initrd} procedure also handles common use cases that
23456 involves using the system as a QEMU guest, or as a ``live'' system with
23457 volatile root file system.
23459 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
23460 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
23461 such as trying to guess which kernel modules and packages should be included
23462 to the initrd. An example use of @code{raw-initrd} is when a user has
23463 a custom Linux kernel configuration and default kernel modules included by
23464 @code{base-initrd} are not available.
23466 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
23467 honors several options passed on the Linux kernel command line
23468 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
23469 @code{-append} option of QEMU), notably:
23472 @item --load=@var{boot}
23473 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
23474 program, once it has mounted the root file system.
23476 Guix uses this option to yield control to a boot program that runs the
23477 service activation programs and then spawns the GNU@tie{}Shepherd, the
23478 initialization system.
23480 @item --root=@var{root}
23481 Mount @var{root} as the root file system. @var{root} can be a
23482 device name like @code{/dev/sda1}, a file system label, or a file system
23485 @item --system=@var{system}
23486 Have @file{/run/booted-system} and @file{/run/current-system} point to
23489 @item modprobe.blacklist=@var{modules}@dots{}
23490 @cindex module, black-listing
23491 @cindex black list, of kernel modules
23492 Instruct the initial RAM disk as well as the @command{modprobe} command
23493 (from the kmod package) to refuse to load @var{modules}. @var{modules}
23494 must be a comma-separated list of module names---e.g.,
23495 @code{usbkbd,9pnet}.
23498 Start a read-eval-print loop (REPL) from the initial RAM disk before it
23499 tries to load kernel modules and to mount the root file system. Our
23500 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
23501 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
23502 Manual}, for more information on Guile's REPL.
23506 Now that you know all the features that initial RAM disks produced by
23507 @code{base-initrd} and @code{raw-initrd} provide,
23508 here is how to use it and customize it further.
23511 @cindex initial RAM disk
23512 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
23513 [#:linux-modules '()] [#:mapped-devices '()] @
23514 [#:keyboard-layout #f] @
23515 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
23516 Return a derivation that builds a raw initrd. @var{file-systems} is
23517 a list of file systems to be mounted by the initrd, possibly in addition to
23518 the root file system specified on the kernel command line via @code{--root}.
23519 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
23520 @var{mapped-devices} is a list of device mappings to realize before
23521 @var{file-systems} are mounted (@pxref{Mapped Devices}).
23522 @var{helper-packages} is a list of packages to be copied in the initrd. It may
23523 include @code{e2fsck/static} or other packages needed by the initrd to check
23524 the root file system.
23526 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
23527 the desired console keyboard layout. This is done before @var{mapped-devices}
23528 are set up and before @var{file-systems} are mounted such that, should the
23529 user need to enter a passphrase or use the REPL, this happens using the
23530 intended keyboard layout.
23532 When @var{qemu-networking?} is true, set up networking with the standard QEMU
23533 parameters. When @var{virtio?} is true, load additional modules so that the
23534 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
23536 When @var{volatile-root?} is true, the root file system is writable but any changes
23540 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
23541 [#:mapped-devices '()] [#:keyboard-layout #f] @
23542 [#:qemu-networking? #f] [#:volatile-root? #f] @
23543 [#:linux-modules '()]
23544 Return as a file-like object a generic initrd, with kernel
23545 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
23546 mounted by the initrd, possibly in addition to the root file system specified
23547 on the kernel command line via @code{--root}. @var{mapped-devices} is a list of device
23548 mappings to realize before @var{file-systems} are mounted.
23550 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
23551 the desired console keyboard layout. This is done before @var{mapped-devices}
23552 are set up and before @var{file-systems} are mounted such that, should the
23553 user need to enter a passphrase or use the REPL, this happens using the
23554 intended keyboard layout.
23556 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
23558 The initrd is automatically populated with all the kernel modules necessary
23559 for @var{file-systems} and for the given options. Additional kernel
23560 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
23561 loaded at boot time in the order in which they appear.
23564 Needless to say, the initrds we produce and use embed a
23565 statically-linked Guile, and the initialization program is a Guile
23566 program. That gives a lot of flexibility. The
23567 @code{expression->initrd} procedure builds such an initrd, given the
23568 program to run in that initrd.
23570 @deffn {Scheme Procedure} expression->initrd @var{exp} @
23571 [#:guile %guile-static-stripped] [#:name "guile-initrd"]
23572 Return as a file-like object a Linux initrd (a gzipped cpio archive)
23573 containing @var{guile} and that evaluates @var{exp}, a G-expression,
23574 upon booting. All the derivations referenced by @var{exp} are
23575 automatically copied to the initrd.
23578 @node Bootloader Configuration
23579 @section Bootloader Configuration
23582 @cindex boot loader
23584 The operating system supports multiple bootloaders. The bootloader is
23585 configured using @code{bootloader-configuration} declaration. All the
23586 fields of this structure are bootloader agnostic except for one field,
23587 @code{bootloader} that indicates the bootloader to be configured and
23590 Some of the bootloaders do not honor every field of
23591 @code{bootloader-configuration}. For instance, the extlinux
23592 bootloader does not support themes and thus ignores the @code{theme}
23595 @deftp {Data Type} bootloader-configuration
23596 The type of a bootloader configuration declaration.
23600 @item @code{bootloader}
23601 @cindex EFI, bootloader
23602 @cindex UEFI, bootloader
23603 @cindex BIOS, bootloader
23604 The bootloader to use, as a @code{bootloader} object. For now
23605 @code{grub-bootloader}, @code{grub-efi-bootloader},
23606 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
23608 @vindex grub-efi-bootloader
23609 @code{grub-efi-bootloader} allows to boot on modern systems using the
23610 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
23611 use if the installation image contains a @file{/sys/firmware/efi} directory
23612 when you boot it on your system.
23614 @vindex grub-bootloader
23615 @code{grub-bootloader} allows you to boot in particular Intel-based machines
23616 in ``legacy'' BIOS mode.
23618 @cindex ARM, bootloaders
23619 @cindex AArch64, bootloaders
23620 Available bootloaders are described in @code{(gnu bootloader @dots{})}
23621 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
23622 of bootloaders for a wide range of ARM and AArch64 systems, using the
23623 @uref{http://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
23625 @item @code{target}
23626 This is a string denoting the target onto which to install the
23629 The interpretation depends on the bootloader in question. For
23630 @code{grub-bootloader}, for example, it should be a device name understood by
23631 the bootloader @command{installer} command, such as @code{/dev/sda} or
23632 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
23633 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
23634 system, usually @file{/boot/efi}.
23636 @item @code{menu-entries} (default: @code{()})
23637 A possibly empty list of @code{menu-entry} objects (see below), denoting
23638 entries to appear in the bootloader menu, in addition to the current
23639 system entry and the entry pointing to previous system generations.
23641 @item @code{default-entry} (default: @code{0})
23642 The index of the default boot menu entry. Index 0 is for the entry of the
23645 @item @code{timeout} (default: @code{5})
23646 The number of seconds to wait for keyboard input before booting. Set to
23647 0 to boot immediately, and to -1 to wait indefinitely.
23649 @cindex keyboard layout, for the bootloader
23650 @item @code{keyboard-layout} (default: @code{#f})
23651 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
23652 layout, usually US@tie{}English (``qwerty'').
23654 Otherwise, this must be a @code{keyboard-layout} object. For instance, the
23655 following example defines a standard German keyboard layout:
23658 (keyboard-layout "de")
23662 while the example below designates the bépo layout for French:
23665 (keyboard-layout "fr" "bepo")
23668 The layout name and variant must match an existing layout in the
23669 @code{xkeyboard-config} package under the @file{share/X11/xkb/symbols}
23673 This option is currently ignored by bootloaders other than @code{grub} and
23677 @item @code{theme} (default: @var{#f})
23678 The bootloader theme object describing the theme to use. If no theme
23679 is provided, some bootloaders might use a default theme, that's true
23682 @item @code{terminal-outputs} (default: @code{'gfxterm})
23683 The output terminals used for the bootloader boot menu, as a list of
23684 symbols. GRUB accepts the values: @code{console}, @code{serial},
23685 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
23686 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
23687 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
23688 configuration,,, grub,GNU GRUB manual}).
23690 @item @code{terminal-inputs} (default: @code{'()})
23691 The input terminals used for the bootloader boot menu, as a list of
23692 symbols. For GRUB, the default is the native platform terminal as
23693 determined at run-time. GRUB accepts the values: @code{console},
23694 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
23695 @code{usb_keyboard}. This field corresponds to the GRUB variable
23696 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
23699 @item @code{serial-unit} (default: @code{#f})
23700 The serial unit used by the bootloader, as an integer from 0 to 3.
23701 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
23702 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
23704 @item @code{serial-speed} (default: @code{#f})
23705 The speed of the serial interface, as an integer. For GRUB, the
23706 default value is chosen at run-time; currently GRUB chooses
23707 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
23714 Should you want to list additional boot menu entries @i{via} the
23715 @code{menu-entries} field above, you will need to create them with the
23716 @code{menu-entry} form. For example, imagine you want to be able to
23717 boot another distro (hard to imagine!), you can define a menu entry
23722 (label "The Other Distro")
23723 (linux "/boot/old/vmlinux-2.6.32")
23724 (linux-arguments '("root=/dev/sda2"))
23725 (initrd "/boot/old/initrd"))
23730 @deftp {Data Type} menu-entry
23731 The type of an entry in the bootloader menu.
23736 The label to show in the menu---e.g., @code{"GNU"}.
23739 The Linux kernel image to boot, for example:
23742 (file-append linux-libre "/bzImage")
23745 For GRUB, it is also possible to specify a device explicitly in the
23746 file path using GRUB's device naming convention (@pxref{Naming
23747 convention,,, grub, GNU GRUB manual}), for example:
23750 "(hd0,msdos1)/boot/vmlinuz"
23753 If the device is specified explicitly as above, then the @code{device}
23754 field is ignored entirely.
23756 @item @code{linux-arguments} (default: @code{()})
23757 The list of extra Linux kernel command-line arguments---e.g.,
23758 @code{("console=ttyS0")}.
23760 @item @code{initrd}
23761 A G-Expression or string denoting the file name of the initial RAM disk
23762 to use (@pxref{G-Expressions}).
23763 @item @code{device} (default: @code{#f})
23764 The device where the kernel and initrd are to be found---i.e., for GRUB,
23765 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
23767 This may be a file system label (a string), a file system UUID (a
23768 bytevector, @pxref{File Systems}), or @code{#f}, in which case
23769 the bootloader will search the device containing the file specified by
23770 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
23771 must @emph{not} be an OS device name such as @file{/dev/sda1}.
23776 @c FIXME: Write documentation once it's stable.
23777 Fow now only GRUB has theme support. GRUB themes are created using
23778 the @code{grub-theme} form, which is not documented yet.
23780 @defvr {Scheme Variable} %default-theme
23781 This is the default GRUB theme used by the operating system if no
23782 @code{theme} field is specified in @code{bootloader-configuration}
23785 It comes with a fancy background image displaying the GNU and Guix
23790 @node Invoking guix system
23791 @section Invoking @code{guix system}
23793 Once you have written an operating system declaration as seen in the
23794 previous section, it can be @dfn{instantiated} using the @command{guix
23795 system} command. The synopsis is:
23798 guix system @var{options}@dots{} @var{action} @var{file}
23801 @var{file} must be the name of a file containing an
23802 @code{operating-system} declaration. @var{action} specifies how the
23803 operating system is instantiated. Currently the following values are
23808 Display available service type definitions that match the given regular
23809 expressions, sorted by relevance:
23812 $ guix system search console font
23813 name: console-fonts
23814 location: gnu/services/base.scm:729:2
23815 extends: shepherd-root
23816 description: Install the given fonts on the specified ttys (fonts are
23817 + per virtual console on GNU/Linux). The value of this service is a list
23818 + of tty/font pairs like:
23820 + '(("tty1" . "LatGrkCyr-8x16"))
23824 location: gnu/services/base.scm:1048:2
23825 extends: shepherd-root
23826 description: Provide console login using the `mingetty' program.
23830 location: gnu/services/base.scm:775:2
23832 description: Provide a console log-in service as specified by its
23833 + configuration value, a `login-configuration' object.
23839 As for @command{guix package --search}, the result is written in
23840 @code{recutils} format, which makes it easy to filter the output
23841 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
23844 Build the operating system described in @var{file}, activate it, and
23845 switch to it@footnote{This action (and the related actions
23846 @code{switch-generation} and @code{roll-back}) are usable only on
23847 systems already running Guix System.}.
23849 This effects all the configuration specified in @var{file}: user
23850 accounts, system services, global package list, setuid programs, etc.
23851 The command starts system services specified in @var{file} that are not
23852 currently running; if a service is currently running this command will
23853 arrange for it to be upgraded the next time it is stopped (e.g.@: by
23854 @code{herd stop X} or @code{herd restart X}).
23856 This command creates a new generation whose number is one greater than
23857 the current generation (as reported by @command{guix system
23858 list-generations}). If that generation already exists, it will be
23859 overwritten. This behavior mirrors that of @command{guix package}
23860 (@pxref{Invoking guix package}).
23862 It also adds a bootloader menu entry for the new OS configuration,
23863 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
23864 entries for older configurations to a submenu, allowing you to choose
23865 an older system generation at boot time should you need it.
23868 @c The paragraph below refers to the problem discussed at
23869 @c <http://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
23870 It is highly recommended to run @command{guix pull} once before you run
23871 @command{guix system reconfigure} for the first time (@pxref{Invoking
23872 guix pull}). Failing to do that you would see an older version of Guix
23873 once @command{reconfigure} has completed.
23876 @item switch-generation
23877 @cindex generations
23878 Switch to an existing system generation. This action atomically
23879 switches the system profile to the specified system generation. It
23880 also rearranges the system's existing bootloader menu entries. It
23881 makes the menu entry for the specified system generation the default,
23882 and it moves the entries for the other generatiors to a submenu, if
23883 supported by the bootloader being used. The next time the system
23884 boots, it will use the specified system generation.
23886 The bootloader itself is not being reinstalled when using this
23887 command. Thus, the installed bootloader is used with an updated
23888 configuration file.
23890 The target generation can be specified explicitly by its generation
23891 number. For example, the following invocation would switch to system
23895 guix system switch-generation 7
23898 The target generation can also be specified relative to the current
23899 generation with the form @code{+N} or @code{-N}, where @code{+3} means
23900 ``3 generations ahead of the current generation,'' and @code{-1} means
23901 ``1 generation prior to the current generation.'' When specifying a
23902 negative value such as @code{-1}, you must precede it with @code{--} to
23903 prevent it from being parsed as an option. For example:
23906 guix system switch-generation -- -1
23909 Currently, the effect of invoking this action is @emph{only} to switch
23910 the system profile to an existing generation and rearrange the
23911 bootloader menu entries. To actually start using the target system
23912 generation, you must reboot after running this action. In the future,
23913 it will be updated to do the same things as @command{reconfigure},
23914 like activating and deactivating services.
23916 This action will fail if the specified generation does not exist.
23919 @cindex rolling back
23920 Switch to the preceding system generation. The next time the system
23921 boots, it will use the preceding system generation. This is the inverse
23922 of @command{reconfigure}, and it is exactly the same as invoking
23923 @command{switch-generation} with an argument of @code{-1}.
23925 Currently, as with @command{switch-generation}, you must reboot after
23926 running this action to actually start using the preceding system
23929 @item delete-generations
23930 @cindex deleting system generations
23931 @cindex saving space
23932 Delete system generations, making them candidates for garbage collection
23933 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
23936 This works in the same way as @command{guix package --delete-generations}
23937 (@pxref{Invoking guix package, @code{--delete-generations}}). With no
23938 arguments, all system generations but the current one are deleted:
23941 guix system delete-generations
23944 You can also select the generations you want to delete. The example below
23945 deletes all the system generations that are more than two month old:
23948 guix system delete-generations 2m
23951 Running this command automatically reinstalls the bootloader with an updated
23952 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
23953 longer lists the generations that have been deleted.
23956 Build the derivation of the operating system, which includes all the
23957 configuration files and programs needed to boot and run the system.
23958 This action does not actually install anything.
23961 Populate the given directory with all the files necessary to run the
23962 operating system specified in @var{file}. This is useful for first-time
23963 installations of Guix System. For instance:
23966 guix system init my-os-config.scm /mnt
23969 copies to @file{/mnt} all the store items required by the configuration
23970 specified in @file{my-os-config.scm}. This includes configuration
23971 files, packages, and so on. It also creates other essential files
23972 needed for the system to operate correctly---e.g., the @file{/etc},
23973 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
23975 This command also installs bootloader on the target specified in
23976 @file{my-os-config}, unless the @option{--no-bootloader} option was
23980 @cindex virtual machine
23982 @anchor{guix system vm}
23983 Build a virtual machine that contains the operating system declared in
23984 @var{file}, and return a script to run that virtual machine (VM).
23987 The @code{vm} action and others below
23988 can use KVM support in the Linux-libre kernel. Specifically, if the
23989 machine has hardware virtualization support, the corresponding
23990 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
23991 must exist and be readable and writable by the user and by the
23992 build users of the daemon (@pxref{Build Environment Setup}).
23995 Arguments given to the script are passed to QEMU as in the example
23996 below, which enables networking and requests 1@tie{}GiB of RAM for the
24000 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -net user
24003 The VM shares its store with the host system.
24005 Additional file systems can be shared between the host and the VM using
24006 the @code{--share} and @code{--expose} command-line options: the former
24007 specifies a directory to be shared with write access, while the latter
24008 provides read-only access to the shared directory.
24010 The example below creates a VM in which the user's home directory is
24011 accessible read-only, and where the @file{/exchange} directory is a
24012 read-write mapping of @file{$HOME/tmp} on the host:
24015 guix system vm my-config.scm \
24016 --expose=$HOME --share=$HOME/tmp=/exchange
24019 On GNU/Linux, the default is to boot directly to the kernel; this has
24020 the advantage of requiring only a very tiny root disk image since the
24021 store of the host can then be mounted.
24023 The @code{--full-boot} option forces a complete boot sequence, starting
24024 with the bootloader. This requires more disk space since a root image
24025 containing at least the kernel, initrd, and bootloader data files must
24026 be created. The @code{--image-size} option can be used to specify the
24029 @cindex System images, creation in various formats
24030 @cindex Creating system images in various formats
24033 @itemx docker-image
24034 Return a virtual machine, disk image, or Docker image of the operating
24035 system declared in @var{file} that stands alone. By default,
24036 @command{guix system} estimates the size of the image needed to store
24037 the system, but you can use the @option{--image-size} option to specify
24038 a value. Docker images are built to contain exactly what they need, so
24039 the @option{--image-size} option is ignored in the case of
24040 @code{docker-image}.
24042 You can specify the root file system type by using the
24043 @option{--file-system-type} option. It defaults to @code{ext4}.
24045 When using @code{vm-image}, the returned image is in qcow2 format, which
24046 the QEMU emulator can efficiently use. @xref{Running Guix in a VM},
24047 for more information on how to run the image in a virtual machine.
24049 When using @code{disk-image}, a raw disk image is produced; it can be
24050 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
24051 the device corresponding to a USB stick, one can copy the image to it
24052 using the following command:
24055 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc
24058 When using @code{docker-image}, a Docker image is produced. Guix builds
24059 the image from scratch, not from a pre-existing Docker base image. As a
24060 result, it contains @emph{exactly} what you define in the operating
24061 system configuration file. You can then load the image and launch a
24062 Docker container using commands like the following:
24065 image_id="$(docker load < guix-system-docker-image.tar.gz)"
24066 docker run -e GUIX_NEW_SYSTEM=/var/guix/profiles/system \\
24067 --entrypoint /var/guix/profiles/system/profile/bin/guile \\
24068 $image_id /var/guix/profiles/system/boot
24071 This command starts a new Docker container from the specified image. It
24072 will boot the Guix system in the usual manner, which means it will
24073 start any services you have defined in the operating system
24074 configuration. Depending on what you run in the Docker container, it
24075 may be necessary to give the container additional permissions. For
24076 example, if you intend to build software using Guix inside of the Docker
24077 container, you may need to pass the @option{--privileged} option to
24081 Return a script to run the operating system declared in @var{file}
24082 within a container. Containers are a set of lightweight isolation
24083 mechanisms provided by the kernel Linux-libre. Containers are
24084 substantially less resource-demanding than full virtual machines since
24085 the kernel, shared objects, and other resources can be shared with the
24086 host system; this also means they provide thinner isolation.
24088 Currently, the script must be run as root in order to support more than
24089 a single user and group. The container shares its store with the host
24092 As with the @code{vm} action (@pxref{guix system vm}), additional file
24093 systems to be shared between the host and container can be specified
24094 using the @option{--share} and @option{--expose} options:
24097 guix system container my-config.scm \
24098 --expose=$HOME --share=$HOME/tmp=/exchange
24102 This option requires Linux-libre 3.19 or newer.
24107 @var{options} can contain any of the common build options (@pxref{Common
24108 Build Options}). In addition, @var{options} can contain one of the
24112 @item --expression=@var{expr}
24113 @itemx -e @var{expr}
24114 Consider the operating-system @var{expr} evaluates to.
24115 This is an alternative to specifying a file which evaluates to an
24117 This is used to generate the Guix system installer @pxref{Building the
24118 Installation Image}).
24120 @item --system=@var{system}
24121 @itemx -s @var{system}
24122 Attempt to build for @var{system} instead of the host system type.
24123 This works as per @command{guix build} (@pxref{Invoking guix build}).
24127 Return the derivation file name of the given operating system without
24130 @item --file-system-type=@var{type}
24131 @itemx -t @var{type}
24132 For the @code{disk-image} action, create a file system of the given
24133 @var{type} on the image.
24135 When this option is omitted, @command{guix system} uses @code{ext4}.
24137 @cindex ISO-9660 format
24138 @cindex CD image format
24139 @cindex DVD image format
24140 @code{--file-system-type=iso9660} produces an ISO-9660 image, suitable
24141 for burning on CDs and DVDs.
24143 @item --image-size=@var{size}
24144 For the @code{vm-image} and @code{disk-image} actions, create an image
24145 of the given @var{size}. @var{size} may be a number of bytes, or it may
24146 include a unit as a suffix (@pxref{Block size, size specifications,,
24147 coreutils, GNU Coreutils}).
24149 When this option is omitted, @command{guix system} computes an estimate
24150 of the image size as a function of the size of the system declared in
24153 @item --root=@var{file}
24154 @itemx -r @var{file}
24155 Make @var{file} a symlink to the result, and register it as a garbage
24158 @item --skip-checks
24159 Skip pre-installation safety checks.
24161 By default, @command{guix system init} and @command{guix system
24162 reconfigure} perform safety checks: they make sure the file systems that
24163 appear in the @code{operating-system} declaration actually exist
24164 (@pxref{File Systems}), and that any Linux kernel modules that may be
24165 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
24166 RAM Disk}). Passing this option skips these tests altogether.
24169 @cindex on-error strategy
24170 @cindex error strategy
24171 @item --on-error=@var{strategy}
24172 Apply @var{strategy} when an error occurs when reading @var{file}.
24173 @var{strategy} may be one of the following:
24176 @item nothing-special
24177 Report the error concisely and exit. This is the default strategy.
24180 Likewise, but also display a backtrace.
24183 Report the error and enter Guile's debugger. From there, you can run
24184 commands such as @code{,bt} to get a backtrace, @code{,locals} to
24185 display local variable values, and more generally inspect the state of the
24186 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
24187 a list of available debugging commands.
24191 Once you have built, configured, re-configured, and re-re-configured
24192 your Guix installation, you may find it useful to list the operating
24193 system generations available on disk---and that you can choose from the
24194 bootloader boot menu:
24198 @item list-generations
24199 List a summary of each generation of the operating system available on
24200 disk, in a human-readable way. This is similar to the
24201 @option{--list-generations} option of @command{guix package}
24202 (@pxref{Invoking guix package}).
24204 Optionally, one can specify a pattern, with the same syntax that is used
24205 in @command{guix package --list-generations}, to restrict the list of
24206 generations displayed. For instance, the following command displays
24207 generations that are up to 10 days old:
24210 $ guix system list-generations 10d
24215 The @command{guix system} command has even more to offer! The following
24216 sub-commands allow you to visualize how your system services relate to
24219 @anchor{system-extension-graph}
24222 @item extension-graph
24223 Emit in Dot/Graphviz format to standard output the @dfn{service
24224 extension graph} of the operating system defined in @var{file}
24225 (@pxref{Service Composition}, for more information on service
24231 $ guix system extension-graph @var{file} | dot -Tpdf > services.pdf
24234 produces a PDF file showing the extension relations among services.
24236 @anchor{system-shepherd-graph}
24237 @item shepherd-graph
24238 Emit in Dot/Graphviz format to standard output the @dfn{dependency
24239 graph} of shepherd services of the operating system defined in
24240 @var{file}. @xref{Shepherd Services}, for more information and for an
24245 @node Running Guix in a VM
24246 @section Running Guix in a Virtual Machine
24248 @cindex virtual machine
24249 To run Guix in a virtual machine (VM), one can either use the
24250 pre-built Guix VM image distributed at
24251 @indicateurl{https://alpha.gnu.org/gnu/guix/guix-system-vm-image-@value{VERSION}.@var{system}.xz}
24252 , or build their own virtual machine image using @command{guix system
24253 vm-image} (@pxref{Invoking guix system}). The returned image is in
24254 qcow2 format, which the @uref{http://qemu.org/, QEMU emulator} can
24258 If you built your own image, you must copy it out of the store
24259 (@pxref{The Store}) and give yourself permission to write to the copy
24260 before you can use it. When invoking QEMU, you must choose a system
24261 emulator that is suitable for your hardware platform. Here is a minimal
24262 QEMU invocation that will boot the result of @command{guix system
24263 vm-image} on x86_64 hardware:
24266 $ qemu-system-x86_64 \
24267 -net user -net nic,model=virtio \
24268 -enable-kvm -m 256 /tmp/qemu-image
24271 Here is what each of these options means:
24274 @item qemu-system-x86_64
24275 This specifies the hardware platform to emulate. This should match the
24279 Enable the unprivileged user-mode network stack. The guest OS can
24280 access the host but not vice versa. This is the simplest way to get the
24283 @item -net nic,model=virtio
24284 You must create a network interface of a given model. If you do not
24285 create a NIC, the boot will fail. Assuming your hardware platform is
24286 x86_64, you can get a list of available NIC models by running
24287 @command{qemu-system-x86_64 -net nic,model=help}.
24290 If your system has hardware virtualization extensions, enabling the
24291 virtual machine support (KVM) of the Linux kernel will make things run
24295 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
24296 which may be insufficient for some operations.
24298 @item /tmp/qemu-image
24299 The file name of the qcow2 image.
24302 The default @command{run-vm.sh} script that is returned by an invocation of
24303 @command{guix system vm} does not add a @command{-net user} flag by default.
24304 To get network access from within the vm add the @code{(dhcp-client-service)}
24305 to your system definition and start the VM using
24306 @command{`guix system vm config.scm` -net user}. An important caveat of using
24307 @command{-net user} for networking is that @command{ping} will not work, because
24308 it uses the ICMP protocol. You'll have to use a different command to check for
24309 network connectivity, for example @command{guix download}.
24311 @subsection Connecting Through SSH
24315 To enable SSH inside a VM you need to add a SSH server like @code{(dropbear-service)}
24316 or @code{(lsh-service)} to your VM. The @code{(lsh-service}) doesn't currently
24317 boot unsupervised. It requires you to type some characters to initialize the
24318 randomness generator. In addition you need to forward the SSH port, 22 by
24319 default, to the host. You can do this with
24322 `guix system vm config.scm` -net user,hostfwd=tcp::10022-:22
24325 To connect to the VM you can run
24328 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
24331 The @command{-p} tells @command{ssh} the port you want to connect to.
24332 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
24333 every time you modify your @command{config.scm} file and the
24334 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
24335 connection to an unknown host every time you connect.
24337 @subsection Using @command{virt-viewer} with Spice
24339 As an alternative to the default @command{qemu} graphical client you can
24340 use the @command{remote-viewer} from the @command{virt-viewer} package. To
24341 connect pass the @command{-spice port=5930,disable-ticketing} flag to
24342 @command{qemu}. See previous section for further information on how to do this.
24344 Spice also allows you to do some nice stuff like share your clipboard with your
24345 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
24348 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
24349 -chardev spicevmc,name=vdagent,id=vdagent
24350 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
24351 name=com.redhat.spice.0
24354 You'll also need to add the @pxref{Miscellaneous Services, Spice service}.
24356 @node Defining Services
24357 @section Defining Services
24359 The previous sections show the available services and how one can combine
24360 them in an @code{operating-system} declaration. But how do we define
24361 them in the first place? And what is a service anyway?
24364 * Service Composition:: The model for composing services.
24365 * Service Types and Services:: Types and services.
24366 * Service Reference:: API reference.
24367 * Shepherd Services:: A particular type of service.
24370 @node Service Composition
24371 @subsection Service Composition
24375 Here we define a @dfn{service} as, broadly, something that extends the
24376 functionality of the operating system. Often a service is a process---a
24377 @dfn{daemon}---started when the system boots: a secure shell server, a
24378 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
24379 whose execution can be triggered by another daemon---e.g., an FTP server
24380 started by @command{inetd} or a D-Bus service activated by
24381 @command{dbus-daemon}. Occasionally, a service does not map to a
24382 daemon. For instance, the ``account'' service collects user accounts
24383 and makes sure they exist when the system runs; the ``udev'' service
24384 collects device management rules and makes them available to the eudev
24385 daemon; the @file{/etc} service populates the @file{/etc} directory
24388 @cindex service extensions
24389 Guix system services are connected by @dfn{extensions}. For instance, the
24390 secure shell service @emph{extends} the Shepherd---the
24391 initialization system, running as PID@tie{}1---by giving it the command
24392 lines to start and stop the secure shell daemon (@pxref{Networking
24393 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
24394 service by passing it its @file{.service} specification, and extends the
24395 udev service by passing it device management rules (@pxref{Desktop
24396 Services, @code{upower-service}}); the Guix daemon service extends the
24397 Shepherd by passing it the command lines to start and stop the daemon,
24398 and extends the account service by passing it a list of required build
24399 user accounts (@pxref{Base Services}).
24401 All in all, services and their ``extends'' relations form a directed
24402 acyclic graph (DAG). If we represent services as boxes and extensions
24403 as arrows, a typical system might provide something like this:
24405 @image{images/service-graph,,5in,Typical service extension graph.}
24407 @cindex system service
24408 At the bottom, we see the @dfn{system service}, which produces the
24409 directory containing everything to run and boot the system, as returned
24410 by the @command{guix system build} command. @xref{Service Reference},
24411 to learn about the other service types shown here.
24412 @xref{system-extension-graph, the @command{guix system extension-graph}
24413 command}, for information on how to generate this representation for a
24414 particular operating system definition.
24416 @cindex service types
24417 Technically, developers can define @dfn{service types} to express these
24418 relations. There can be any number of services of a given type on the
24419 system---for instance, a system running two instances of the GNU secure
24420 shell server (lsh) has two instances of @code{lsh-service-type}, with
24421 different parameters.
24423 The following section describes the programming interface for service
24424 types and services.
24426 @node Service Types and Services
24427 @subsection Service Types and Services
24429 A @dfn{service type} is a node in the DAG described above. Let us start
24430 with a simple example, the service type for the Guix build daemon
24431 (@pxref{Invoking guix-daemon}):
24434 (define guix-service-type
24438 (list (service-extension shepherd-root-service-type guix-shepherd-service)
24439 (service-extension account-service-type guix-accounts)
24440 (service-extension activation-service-type guix-activation)))
24441 (default-value (guix-configuration))))
24445 It defines three things:
24449 A name, whose sole purpose is to make inspection and debugging easier.
24452 A list of @dfn{service extensions}, where each extension designates the
24453 target service type and a procedure that, given the parameters of the
24454 service, returns a list of objects to extend the service of that type.
24456 Every service type has at least one service extension. The only
24457 exception is the @dfn{boot service type}, which is the ultimate service.
24460 Optionally, a default value for instances of this type.
24463 In this example, @var{guix-service-type} extends three services:
24466 @item shepherd-root-service-type
24467 The @var{guix-shepherd-service} procedure defines how the Shepherd
24468 service is extended. Namely, it returns a @code{<shepherd-service>}
24469 object that defines how @command{guix-daemon} is started and stopped
24470 (@pxref{Shepherd Services}).
24472 @item account-service-type
24473 This extension for this service is computed by @var{guix-accounts},
24474 which returns a list of @code{user-group} and @code{user-account}
24475 objects representing the build user accounts (@pxref{Invoking
24478 @item activation-service-type
24479 Here @var{guix-activation} is a procedure that returns a gexp, which is
24480 a code snippet to run at ``activation time''---e.g., when the service is
24484 A service of this type is instantiated like this:
24487 (service guix-service-type
24488 (guix-configuration
24490 (use-substitutes? #f)))
24493 The second argument to the @code{service} form is a value representing
24494 the parameters of this specific service instance.
24495 @xref{guix-configuration-type, @code{guix-configuration}}, for
24496 information about the @code{guix-configuration} data type. When the
24497 value is omitted, the default value specified by
24498 @code{guix-service-type} is used:
24501 (service guix-service-type)
24504 @var{guix-service-type} is quite simple because it extends other
24505 services but is not extensible itself.
24507 @c @subsubsubsection Extensible Service Types
24509 The service type for an @emph{extensible} service looks like this:
24512 (define udev-service-type
24513 (service-type (name 'udev)
24515 (list (service-extension shepherd-root-service-type
24516 udev-shepherd-service)))
24518 (compose concatenate) ;concatenate the list of rules
24519 (extend (lambda (config rules)
24521 (($ <udev-configuration> udev initial-rules)
24522 (udev-configuration
24523 (udev udev) ;the udev package to use
24524 (rules (append initial-rules rules)))))))))
24527 This is the service type for the
24528 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
24529 management daemon}. Compared to the previous example, in addition to an
24530 extension of @var{shepherd-root-service-type}, we see two new fields:
24534 This is the procedure to @dfn{compose} the list of extensions to
24535 services of this type.
24537 Services can extend the udev service by passing it lists of rules; we
24538 compose those extensions simply by concatenating them.
24541 This procedure defines how the value of the service is @dfn{extended} with
24542 the composition of the extensions.
24544 Udev extensions are composed into a list of rules, but the udev service
24545 value is itself a @code{<udev-configuration>} record. So here, we
24546 extend that record by appending the list of rules it contains to the
24547 list of contributed rules.
24550 This is a string giving an overview of the service type. The string can
24551 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
24552 @command{guix system search} command searches these strings and displays
24553 them (@pxref{Invoking guix system}).
24556 There can be only one instance of an extensible service type such as
24557 @var{udev-service-type}. If there were more, the
24558 @code{service-extension} specifications would be ambiguous.
24560 Still here? The next section provides a reference of the programming
24561 interface for services.
24563 @node Service Reference
24564 @subsection Service Reference
24566 We have seen an overview of service types (@pxref{Service Types and
24567 Services}). This section provides a reference on how to manipulate
24568 services and service types. This interface is provided by the
24569 @code{(gnu services)} module.
24571 @deffn {Scheme Procedure} service @var{type} [@var{value}]
24572 Return a new service of @var{type}, a @code{<service-type>} object (see
24573 below.) @var{value} can be any object; it represents the parameters of
24574 this particular service instance.
24576 When @var{value} is omitted, the default value specified by @var{type}
24577 is used; if @var{type} does not specify a default value, an error is
24580 For instance, this:
24583 (service openssh-service-type)
24587 is equivalent to this:
24590 (service openssh-service-type
24591 (openssh-configuration))
24594 In both cases the result is an instance of @code{openssh-service-type}
24595 with the default configuration.
24598 @deffn {Scheme Procedure} service? @var{obj}
24599 Return true if @var{obj} is a service.
24602 @deffn {Scheme Procedure} service-kind @var{service}
24603 Return the type of @var{service}---i.e., a @code{<service-type>} object.
24606 @deffn {Scheme Procedure} service-value @var{service}
24607 Return the value associated with @var{service}. It represents its
24611 Here is an example of how a service is created and manipulated:
24615 (service nginx-service-type
24616 (nginx-configuration
24618 (log-directory log-directory)
24619 (run-directory run-directory)
24620 (file config-file))))
24625 (eq? (service-kind s) nginx-service-type)
24629 The @code{modify-services} form provides a handy way to change the
24630 parameters of some of the services of a list such as
24631 @var{%base-services} (@pxref{Base Services, @code{%base-services}}). It
24632 evaluates to a list of services. Of course, you could always use
24633 standard list combinators such as @code{map} and @code{fold} to do that
24634 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
24635 @code{modify-services} simply provides a more concise form for this
24638 @deffn {Scheme Syntax} modify-services @var{services} @
24639 (@var{type} @var{variable} => @var{body}) @dots{}
24641 Modify the services listed in @var{services} according to the given
24642 clauses. Each clause has the form:
24645 (@var{type} @var{variable} => @var{body})
24648 where @var{type} is a service type---e.g.,
24649 @code{guix-service-type}---and @var{variable} is an identifier that is
24650 bound within the @var{body} to the service parameters---e.g., a
24651 @code{guix-configuration} instance---of the original service of that
24654 The @var{body} should evaluate to the new service parameters, which will
24655 be used to configure the new service. This new service will replace the
24656 original in the resulting list. Because a service's service parameters
24657 are created using @code{define-record-type*}, you can write a succinct
24658 @var{body} that evaluates to the new service parameters by using the
24659 @code{inherit} feature that @code{define-record-type*} provides.
24661 @xref{Using the Configuration System}, for example usage.
24665 Next comes the programming interface for service types. This is
24666 something you want to know when writing new service definitions, but not
24667 necessarily when simply looking for ways to customize your
24668 @code{operating-system} declaration.
24670 @deftp {Data Type} service-type
24671 @cindex service type
24672 This is the representation of a @dfn{service type} (@pxref{Service Types
24677 This is a symbol, used only to simplify inspection and debugging.
24679 @item @code{extensions}
24680 A non-empty list of @code{<service-extension>} objects (see below).
24682 @item @code{compose} (default: @code{#f})
24683 If this is @code{#f}, then the service type denotes services that cannot
24684 be extended---i.e., services that do not receive ``values'' from other
24687 Otherwise, it must be a one-argument procedure. The procedure is called
24688 by @code{fold-services} and is passed a list of values collected from
24689 extensions. It may return any single value.
24691 @item @code{extend} (default: @code{#f})
24692 If this is @code{#f}, services of this type cannot be extended.
24694 Otherwise, it must be a two-argument procedure: @code{fold-services}
24695 calls it, passing it the initial value of the service as the first
24696 argument and the result of applying @code{compose} to the extension
24697 values as the second argument. It must return a value that is a valid
24698 parameter value for the service instance.
24701 @xref{Service Types and Services}, for examples.
24704 @deffn {Scheme Procedure} service-extension @var{target-type} @
24706 Return a new extension for services of type @var{target-type}.
24707 @var{compute} must be a one-argument procedure: @code{fold-services}
24708 calls it, passing it the value associated with the service that provides
24709 the extension; it must return a valid value for the target service.
24712 @deffn {Scheme Procedure} service-extension? @var{obj}
24713 Return true if @var{obj} is a service extension.
24716 Occasionally, you might want to simply extend an existing service. This
24717 involves creating a new service type and specifying the extension of
24718 interest, which can be verbose; the @code{simple-service} procedure
24719 provides a shorthand for this.
24721 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
24722 Return a service that extends @var{target} with @var{value}. This works
24723 by creating a singleton service type @var{name}, of which the returned
24724 service is an instance.
24726 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
24730 (simple-service 'my-mcron-job mcron-service-type
24731 #~(job '(next-hour (3)) "guix gc -F 2G"))
24735 At the core of the service abstraction lies the @code{fold-services}
24736 procedure, which is responsible for ``compiling'' a list of services
24737 down to a single directory that contains everything needed to boot and
24738 run the system---the directory shown by the @command{guix system build}
24739 command (@pxref{Invoking guix system}). In essence, it propagates
24740 service extensions down the service graph, updating each node parameters
24741 on the way, until it reaches the root node.
24743 @deffn {Scheme Procedure} fold-services @var{services} @
24744 [#:target-type @var{system-service-type}]
24745 Fold @var{services} by propagating their extensions down to the root of
24746 type @var{target-type}; return the root service adjusted accordingly.
24749 Lastly, the @code{(gnu services)} module also defines several essential
24750 service types, some of which are listed below.
24752 @defvr {Scheme Variable} system-service-type
24753 This is the root of the service graph. It produces the system directory
24754 as returned by the @command{guix system build} command.
24757 @defvr {Scheme Variable} boot-service-type
24758 The type of the ``boot service'', which produces the @dfn{boot script}.
24759 The boot script is what the initial RAM disk runs when booting.
24762 @defvr {Scheme Variable} etc-service-type
24763 The type of the @file{/etc} service. This service is used to create
24764 files under @file{/etc} and can be extended by
24765 passing it name/file tuples such as:
24768 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
24771 In this example, the effect would be to add an @file{/etc/issue} file
24772 pointing to the given file.
24775 @defvr {Scheme Variable} setuid-program-service-type
24776 Type for the ``setuid-program service''. This service collects lists of
24777 executable file names, passed as gexps, and adds them to the set of
24778 setuid-root programs on the system (@pxref{Setuid Programs}).
24781 @defvr {Scheme Variable} profile-service-type
24782 Type of the service that populates the @dfn{system profile}---i.e., the
24783 programs under @file{/run/current-system/profile}. Other services can
24784 extend it by passing it lists of packages to add to the system profile.
24788 @node Shepherd Services
24789 @subsection Shepherd Services
24791 @cindex shepherd services
24793 @cindex init system
24794 The @code{(gnu services shepherd)} module provides a way to define
24795 services managed by the GNU@tie{}Shepherd, which is the
24796 initialization system---the first process that is started when the
24797 system boots, also known as PID@tie{}1
24798 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
24800 Services in the Shepherd can depend on each other. For instance, the
24801 SSH daemon may need to be started after the syslog daemon has been
24802 started, which in turn can only happen once all the file systems have
24803 been mounted. The simple operating system defined earlier (@pxref{Using
24804 the Configuration System}) results in a service graph like this:
24806 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
24808 You can actually generate such a graph for any operating system
24809 definition using the @command{guix system shepherd-graph} command
24810 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
24812 The @var{%shepherd-root-service} is a service object representing
24813 PID@tie{}1, of type @var{shepherd-root-service-type}; it can be extended
24814 by passing it lists of @code{<shepherd-service>} objects.
24816 @deftp {Data Type} shepherd-service
24817 The data type representing a service managed by the Shepherd.
24820 @item @code{provision}
24821 This is a list of symbols denoting what the service provides.
24823 These are the names that may be passed to @command{herd start},
24824 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
24825 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
24826 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
24828 @item @code{requirements} (default: @code{'()})
24829 List of symbols denoting the Shepherd services this one depends on.
24831 @item @code{respawn?} (default: @code{#t})
24832 Whether to restart the service when it stops, for instance when the
24833 underlying process dies.
24836 @itemx @code{stop} (default: @code{#~(const #f)})
24837 The @code{start} and @code{stop} fields refer to the Shepherd's
24838 facilities to start and stop processes (@pxref{Service De- and
24839 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
24840 G-expressions that get expanded in the Shepherd configuration file
24841 (@pxref{G-Expressions}).
24843 @item @code{actions} (default: @code{'()})
24844 @cindex actions, of Shepherd services
24845 This is a list of @code{shepherd-action} objects (see below) defining
24846 @dfn{actions} supported by the service, in addition to the standard
24847 @code{start} and @code{stop} actions. Actions listed here become available as
24848 @command{herd} sub-commands:
24851 herd @var{action} @var{service} [@var{arguments}@dots{}]
24854 @item @code{documentation}
24855 A documentation string, as shown when running:
24858 herd doc @var{service-name}
24861 where @var{service-name} is one of the symbols in @var{provision}
24862 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
24864 @item @code{modules} (default: @var{%default-modules})
24865 This is the list of modules that must be in scope when @code{start} and
24866 @code{stop} are evaluated.
24871 @deftp {Data Type} shepherd-action
24872 This is the data type that defines additional actions implemented by a
24873 Shepherd service (see above).
24877 Symbol naming the action.
24879 @item documentation
24880 This is a documentation string for the action. It can be viewed by running:
24883 herd doc @var{service} action @var{action}
24887 This should be a gexp that evaluates to a procedure of at least one argument,
24888 which is the ``running value'' of the service (@pxref{Slots of services,,,
24889 shepherd, The GNU Shepherd Manual}).
24892 The following example defines an action called @code{say-hello} that kindly
24898 (documentation "Say hi!")
24899 (procedure #~(lambda (running . args)
24900 (format #t "Hello, friend! arguments: ~s\n"
24905 Assuming this action is added to the @code{example} service, then you can do:
24908 # herd say-hello example
24909 Hello, friend! arguments: ()
24910 # herd say-hello example a b c
24911 Hello, friend! arguments: ("a" "b" "c")
24914 This, as you can see, is a fairly sophisticated way to say hello.
24915 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
24919 @defvr {Scheme Variable} shepherd-root-service-type
24920 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
24922 This is the service type that extensions target when they want to create
24923 shepherd services (@pxref{Service Types and Services}, for an example).
24924 Each extension must pass a list of @code{<shepherd-service>}.
24927 @defvr {Scheme Variable} %shepherd-root-service
24928 This service represents PID@tie{}1.
24932 @node Documentation
24933 @chapter Documentation
24935 @cindex documentation, searching for
24936 @cindex searching for documentation
24937 @cindex Info, documentation format
24939 @cindex manual pages
24940 In most cases packages installed with Guix come with documentation.
24941 There are two main documentation formats: ``Info'', a browseable
24942 hypertext format used for GNU software, and ``manual pages'' (or ``man
24943 pages''), the linear documentation format traditionally found on Unix.
24944 Info manuals are accessed with the @command{info} command or with Emacs,
24945 and man pages are accessed using @command{man}.
24947 You can look for documentation of software installed on your system by
24948 keyword. For example, the following command searches for information
24949 about ``TLS'' in Info manuals:
24953 "(emacs)Network Security" -- STARTTLS
24954 "(emacs)Network Security" -- TLS
24955 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
24956 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
24961 The command below searches for the same keyword in man pages:
24965 SSL (7) - OpenSSL SSL/TLS library
24966 certtool (1) - GnuTLS certificate tool
24970 These searches are purely local to your computer so you have the
24971 guarantee that documentation you find corresponds to what you have
24972 actually installed, you can access it off-line, and your privacy is
24975 Once you have these results, you can view the relevant documentation by
24979 $ info "(gnutls)Core TLS API"
24989 Info manuals contain sections and indices as well as hyperlinks like
24990 those found in Web pages. The @command{info} reader (@pxref{Top, Info
24991 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
24992 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
24993 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
24994 Introduction}, for an introduction to Info navigation.
24996 @node Installing Debugging Files
24997 @chapter Installing Debugging Files
24999 @cindex debugging files
25000 Program binaries, as produced by the GCC compilers for instance, are
25001 typically written in the ELF format, with a section containing
25002 @dfn{debugging information}. Debugging information is what allows the
25003 debugger, GDB, to map binary code to source code; it is required to
25004 debug a compiled program in good conditions.
25006 The problem with debugging information is that is takes up a fair amount
25007 of disk space. For example, debugging information for the GNU C Library
25008 weighs in at more than 60 MiB. Thus, as a user, keeping all the
25009 debugging info of all the installed programs is usually not an option.
25010 Yet, space savings should not come at the cost of an impediment to
25011 debugging---especially in the GNU system, which should make it easier
25012 for users to exert their computing freedom (@pxref{GNU Distribution}).
25014 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
25015 mechanism that allows users to get the best of both worlds: debugging
25016 information can be stripped from the binaries and stored in separate
25017 files. GDB is then able to load debugging information from those files,
25018 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
25021 The GNU distribution takes advantage of this by storing debugging
25022 information in the @code{lib/debug} sub-directory of a separate package
25023 output unimaginatively called @code{debug} (@pxref{Packages with
25024 Multiple Outputs}). Users can choose to install the @code{debug} output
25025 of a package when they need it. For instance, the following command
25026 installs the debugging information for the GNU C Library and for GNU
25030 guix package -i glibc:debug guile:debug
25033 GDB must then be told to look for debug files in the user's profile, by
25034 setting the @code{debug-file-directory} variable (consider setting it
25035 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
25039 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
25042 From there on, GDB will pick up debugging information from the
25043 @code{.debug} files under @file{~/.guix-profile/lib/debug}.
25045 In addition, you will most likely want GDB to be able to show the source
25046 code being debugged. To do that, you will have to unpack the source
25047 code of the package of interest (obtained with @code{guix build
25048 --source}, @pxref{Invoking guix build}), and to point GDB to that source
25049 directory using the @code{directory} command (@pxref{Source Path,
25050 @code{directory},, gdb, Debugging with GDB}).
25052 @c XXX: keep me up-to-date
25053 The @code{debug} output mechanism in Guix is implemented by the
25054 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
25055 opt-in---debugging information is available only for the packages
25056 with definitions explicitly declaring a @code{debug} output. This may be
25057 changed to opt-out in the future if our build farm servers can handle
25058 the load. To check whether a package has a @code{debug} output, use
25059 @command{guix package --list-available} (@pxref{Invoking guix package}).
25062 @node Security Updates
25063 @chapter Security Updates
25065 @cindex security updates
25066 @cindex security vulnerabilities
25067 Occasionally, important security vulnerabilities are discovered in software
25068 packages and must be patched. Guix developers try hard to keep track of
25069 known vulnerabilities and to apply fixes as soon as possible in the
25070 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
25071 containing only security updates.) The @command{guix lint} tool helps
25072 developers find out about vulnerable versions of software packages in the
25077 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
25078 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
25079 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
25083 @xref{Invoking guix lint}, for more information.
25086 As of version @value{VERSION}, the feature described below is considered
25090 Guix follows a functional
25091 package management discipline (@pxref{Introduction}), which implies
25092 that, when a package is changed, @emph{every package that depends on it}
25093 must be rebuilt. This can significantly slow down the deployment of
25094 fixes in core packages such as libc or Bash, since basically the whole
25095 distribution would need to be rebuilt. Using pre-built binaries helps
25096 (@pxref{Substitutes}), but deployment may still take more time than
25100 To address this, Guix implements @dfn{grafts}, a mechanism that allows
25101 for fast deployment of critical updates without the costs associated
25102 with a whole-distribution rebuild. The idea is to rebuild only the
25103 package that needs to be patched, and then to ``graft'' it onto packages
25104 explicitly installed by the user and that were previously referring to
25105 the original package. The cost of grafting is typically very low, and
25106 order of magnitudes lower than a full rebuild of the dependency chain.
25108 @cindex replacements of packages, for grafts
25109 For instance, suppose a security update needs to be applied to Bash.
25110 Guix developers will provide a package definition for the ``fixed''
25111 Bash, say @var{bash-fixed}, in the usual way (@pxref{Defining
25112 Packages}). Then, the original package definition is augmented with a
25113 @code{replacement} field pointing to the package containing the bug fix:
25120 (replacement bash-fixed)))
25123 From there on, any package depending directly or indirectly on Bash---as
25124 reported by @command{guix gc --requisites} (@pxref{Invoking guix
25125 gc})---that is installed is automatically ``rewritten'' to refer to
25126 @var{bash-fixed} instead of @var{bash}. This grafting process takes
25127 time proportional to the size of the package, usually less than a
25128 minute for an ``average'' package on a recent machine. Grafting is
25129 recursive: when an indirect dependency requires grafting, then grafting
25130 ``propagates'' up to the package that the user is installing.
25132 Currently, the length of the name and version of the graft and that of
25133 the package it replaces (@var{bash-fixed} and @var{bash} in the example
25134 above) must be equal. This restriction mostly comes from the fact that
25135 grafting works by patching files, including binary files, directly.
25136 Other restrictions may apply: for instance, when adding a graft to a
25137 package providing a shared library, the original shared library and its
25138 replacement must have the same @code{SONAME} and be binary-compatible.
25140 The @option{--no-grafts} command-line option allows you to forcefully
25141 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
25145 guix build bash --no-grafts
25149 returns the store file name of the original Bash, whereas:
25156 returns the store file name of the ``fixed'', replacement Bash. This
25157 allows you to distinguish between the two variants of Bash.
25159 To verify which Bash your whole profile refers to, you can run
25160 (@pxref{Invoking guix gc}):
25163 guix gc -R `readlink -f ~/.guix-profile` | grep bash
25167 @dots{} and compare the store file names that you get with those above.
25168 Likewise for a complete Guix system generation:
25171 guix gc -R `guix system build my-config.scm` | grep bash
25174 Lastly, to check which Bash running processes are using, you can use the
25175 @command{lsof} command:
25178 lsof | grep /gnu/store/.*bash
25182 @node Bootstrapping
25183 @chapter Bootstrapping
25185 @c Adapted from the ELS 2013 paper.
25187 @cindex bootstrapping
25189 Bootstrapping in our context refers to how the distribution gets built
25190 ``from nothing''. Remember that the build environment of a derivation
25191 contains nothing but its declared inputs (@pxref{Introduction}). So
25192 there's an obvious chicken-and-egg problem: how does the first package
25193 get built? How does the first compiler get compiled? Note that this is
25194 a question of interest only to the curious hacker, not to the regular
25195 user, so you can shamelessly skip this section if you consider yourself
25196 a ``regular user''.
25198 @cindex bootstrap binaries
25199 The GNU system is primarily made of C code, with libc at its core. The
25200 GNU build system itself assumes the availability of a Bourne shell and
25201 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
25202 `grep'. Furthermore, build programs---programs that run
25203 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
25204 (@pxref{Derivations}). Consequently, to be able to build anything at
25205 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
25206 Binutils, libc, and the other packages mentioned above---the
25207 @dfn{bootstrap binaries}.
25209 These bootstrap binaries are ``taken for granted'', though we can also
25210 re-create them if needed (more on that later).
25212 @unnumberedsec Preparing to Use the Bootstrap Binaries
25214 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
25215 @c large image, it's hard to scroll. Oh well.
25216 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
25218 The figure above shows the very beginning of the dependency graph of the
25219 distribution, corresponding to the package definitions of the @code{(gnu
25220 packages bootstrap)} module. A similar figure can be generated with
25221 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
25224 guix graph -t derivation \
25225 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
25229 At this level of detail, things are
25230 slightly complex. First, Guile itself consists of an ELF executable,
25231 along with many source and compiled Scheme files that are dynamically
25232 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
25233 tarball shown in this graph. This tarball is part of Guix's ``source''
25234 distribution, and gets inserted into the store with @code{add-to-store}
25235 (@pxref{The Store}).
25237 But how do we write a derivation that unpacks this tarball and adds it
25238 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
25239 derivation---the first one that gets built---uses @code{bash} as its
25240 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
25241 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
25242 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
25243 the Guix source distribution, whose sole purpose is to allow the Guile
25244 tarball to be unpacked.
25246 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
25247 Guile that can be used to run subsequent build programs. Its first task
25248 is to download tarballs containing the other pre-built binaries---this
25249 is what the @code{.tar.xz.drv} derivations do. Guix modules such as
25250 @code{ftp-client.scm} are used for this purpose. The
25251 @code{module-import.drv} derivations import those modules in a directory
25252 in the store, using the original layout. The
25253 @code{module-import-compiled.drv} derivations compile those modules, and
25254 write them in an output directory with the right layout. This
25255 corresponds to the @code{#:modules} argument of
25256 @code{build-expression->derivation} (@pxref{Derivations}).
25258 Finally, the various tarballs are unpacked by the
25259 derivations @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv},
25260 etc., at which point we have a working C tool chain.
25263 @unnumberedsec Building the Build Tools
25265 Bootstrapping is complete when we have a full tool chain that does not
25266 depend on the pre-built bootstrap tools discussed above. This
25267 no-dependency requirement is verified by checking whether the files of
25268 the final tool chain contain references to the @file{/gnu/store}
25269 directories of the bootstrap inputs. The process that leads to this
25270 ``final'' tool chain is described by the package definitions found in
25271 the @code{(gnu packages commencement)} module.
25273 The @command{guix graph} command allows us to ``zoom out'' compared to
25274 the graph above, by looking at the level of package objects instead of
25275 individual derivations---remember that a package may translate to
25276 several derivations, typically one derivation to download its source,
25277 one to build the Guile modules it needs, and one to actually build the
25278 package from source. The command:
25281 guix graph -t bag \
25282 -e '(@@@@ (gnu packages commencement)
25283 glibc-final-with-bootstrap-bash)' | dot -Tps > t.ps
25287 produces the dependency graph leading to the ``final'' C
25288 library@footnote{You may notice the @code{glibc-intermediate} label,
25289 suggesting that it is not @emph{quite} final, but as a good
25290 approximation, we will consider it final.}, depicted below.
25292 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
25294 @c See <http://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
25295 The first tool that gets built with the bootstrap binaries is
25296 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
25297 for all the following packages. From there Findutils and Diffutils get
25300 Then come the first-stage Binutils and GCC, built as pseudo cross
25301 tools---i.e., with @code{--target} equal to @code{--host}. They are
25302 used to build libc. Thanks to this cross-build trick, this libc is
25303 guaranteed not to hold any reference to the initial tool chain.
25305 From there the final Binutils and GCC (not shown above) are built.
25307 from the final Binutils, and links programs against the just-built libc.
25308 This tool chain is used to build the other packages used by Guix and by
25309 the GNU Build System: Guile, Bash, Coreutils, etc.
25311 And voilà! At this point we have the complete set of build tools that
25312 the GNU Build System expects. These are in the @code{%final-inputs}
25313 variable of the @code{(gnu packages commencement)} module, and are
25314 implicitly used by any package that uses @code{gnu-build-system}
25315 (@pxref{Build Systems, @code{gnu-build-system}}).
25318 @unnumberedsec Building the Bootstrap Binaries
25320 @cindex bootstrap binaries
25321 Because the final tool chain does not depend on the bootstrap binaries,
25322 those rarely need to be updated. Nevertheless, it is useful to have an
25323 automated way to produce them, should an update occur, and this is what
25324 the @code{(gnu packages make-bootstrap)} module provides.
25326 The following command builds the tarballs containing the bootstrap
25327 binaries (Guile, Binutils, GCC, libc, and a tarball containing a mixture
25328 of Coreutils and other basic command-line tools):
25331 guix build bootstrap-tarballs
25334 The generated tarballs are those that should be referred to in the
25335 @code{(gnu packages bootstrap)} module mentioned at the beginning of
25338 Still here? Then perhaps by now you've started to wonder: when do we
25339 reach a fixed point? That is an interesting question! The answer is
25340 unknown, but if you would like to investigate further (and have
25341 significant computational and storage resources to do so), then let us
25344 @unnumberedsec Reducing the Set of Bootstrap Binaries
25346 Our bootstrap binaries currently include GCC, Guile, etc. That's a lot
25347 of binary code! Why is that a problem? It's a problem because these
25348 big chunks of binary code are practically non-auditable, which makes it
25349 hard to establish what source code produced them. Every unauditable
25350 binary also leaves us vulnerable to compiler backdoors as described by
25351 Ken Thompson in the 1984 paper @emph{Reflections on Trusting Trust}.
25353 This is mitigated by the fact that our bootstrap binaries were generated
25354 from an earlier Guix revision. Nevertheless it lacks the level of
25355 transparency that we get in the rest of the package dependency graph,
25356 where Guix always gives us a source-to-binary mapping. Thus, our goal
25357 is to reduce the set of bootstrap binaries to the bare minimum.
25359 The @uref{http://bootstrappable.org, Bootstrappable.org web site} lists
25360 on-going projects to do that. One of these is about replacing the
25361 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
25362 of increasing complexity, which could be built from source starting from
25363 a simple and auditable assembler. Your help is welcome!
25367 @chapter Porting to a New Platform
25369 As discussed above, the GNU distribution is self-contained, and
25370 self-containment is achieved by relying on pre-built ``bootstrap
25371 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
25372 operating system kernel, CPU architecture, and application binary
25373 interface (ABI). Thus, to port the distribution to a platform that is
25374 not yet supported, one must build those bootstrap binaries, and update
25375 the @code{(gnu packages bootstrap)} module to use them on that platform.
25377 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
25378 When everything goes well, and assuming the GNU tool chain supports the
25379 target platform, this can be as simple as running a command like this
25383 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
25386 For this to work, the @code{glibc-dynamic-linker} procedure in
25387 @code{(gnu packages bootstrap)} must be augmented to return the right
25388 file name for libc's dynamic linker on that platform; likewise,
25389 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
25390 taught about the new platform.
25392 Once these are built, the @code{(gnu packages bootstrap)} module needs
25393 to be updated to refer to these binaries on the target platform. That
25394 is, the hashes and URLs of the bootstrap tarballs for the new platform
25395 must be added alongside those of the currently supported platforms. The
25396 bootstrap Guile tarball is treated specially: it is expected to be
25397 available locally, and @file{gnu/local.mk} has rules to download it for
25398 the supported architectures; a rule for the new platform must be added
25401 In practice, there may be some complications. First, it may be that the
25402 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
25403 above) is not recognized by all the GNU tools. Typically, glibc
25404 recognizes some of these, whereas GCC uses an extra @code{--with-abi}
25405 configure flag (see @code{gcc.scm} for examples of how to handle this).
25406 Second, some of the required packages could fail to build for that
25407 platform. Lastly, the generated binaries could be broken for some
25410 @c *********************************************************************
25411 @include contributing.texi
25413 @c *********************************************************************
25414 @node Acknowledgments
25415 @chapter Acknowledgments
25417 Guix is based on the @uref{http://nixos.org/nix/, Nix package manager},
25418 which was designed and
25419 implemented by Eelco Dolstra, with contributions from other people (see
25420 the @file{nix/AUTHORS} file in Guix.) Nix pioneered functional package
25421 management, and promoted unprecedented features, such as transactional
25422 package upgrades and rollbacks, per-user profiles, and referentially
25423 transparent build processes. Without this work, Guix would not exist.
25425 The Nix-based software distributions, Nixpkgs and NixOS, have also been
25426 an inspiration for Guix.
25428 GNU@tie{}Guix itself is a collective work with contributions from a
25429 number of people. See the @file{AUTHORS} file in Guix for more
25430 information on these fine people. The @file{THANKS} file lists people
25431 who have helped by reporting bugs, taking care of the infrastructure,
25432 providing artwork and themes, making suggestions, and more---thank you!
25435 @c *********************************************************************
25436 @node GNU Free Documentation License
25437 @appendix GNU Free Documentation License
25438 @cindex license, GNU Free Documentation License
25439 @include fdl-1.3.texi
25441 @c *********************************************************************
25442 @node Concept Index
25443 @unnumbered Concept Index
25446 @node Programming Index
25447 @unnumbered Programming Index
25448 @syncodeindex tp fn
25449 @syncodeindex vr fn
25454 @c Local Variables:
25455 @c ispell-local-dictionary: "american";