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 OPENPGP-SIGNING-KEY-URL https://sv.gnu.org/people/viewgpg.php?user_id=15145
16 @c Base URL for downloads.
17 @set BASE-URL https://ftp.gnu.org/gnu/guix
19 @c The official substitute server used by default.
20 @set SUBSTITUTE-SERVER ci.guix.gnu.org
21 @set SUBSTITUTE-URL https://@value{SUBSTITUTE-SERVER}
24 Copyright @copyright{} 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020 Ludovic Courtès@*
25 Copyright @copyright{} 2013, 2014, 2016 Andreas Enge@*
26 Copyright @copyright{} 2013 Nikita Karetnikov@*
27 Copyright @copyright{} 2014, 2015, 2016 Alex Kost@*
28 Copyright @copyright{} 2015, 2016 Mathieu Lirzin@*
29 Copyright @copyright{} 2014 Pierre-Antoine Rault@*
30 Copyright @copyright{} 2015 Taylan Ulrich Bayırlı/Kammer@*
31 Copyright @copyright{} 2015, 2016, 2017, 2019, 2020 Leo Famulari@*
32 Copyright @copyright{} 2015, 2016, 2017, 2018, 2019, 2020 Ricardo Wurmus@*
33 Copyright @copyright{} 2016 Ben Woodcroft@*
34 Copyright @copyright{} 2016, 2017, 2018 Chris Marusich@*
35 Copyright @copyright{} 2016, 2017, 2018, 2019, 2020 Efraim Flashner@*
36 Copyright @copyright{} 2016 John Darrington@*
37 Copyright @copyright{} 2016, 2017 Nikita Gillmann@*
38 Copyright @copyright{} 2016, 2017, 2018, 2019, 2020 Jan Nieuwenhuizen@*
39 Copyright @copyright{} 2016, 2017, 2018, 2019, 2020 Julien Lepiller@*
40 Copyright @copyright{} 2016 Alex ter Weele@*
41 Copyright @copyright{} 2016, 2017, 2018, 2019 Christopher Baines@*
42 Copyright @copyright{} 2017, 2018, 2019 Clément Lassieur@*
43 Copyright @copyright{} 2017, 2018, 2020 Mathieu Othacehe@*
44 Copyright @copyright{} 2017 Federico Beffa@*
45 Copyright @copyright{} 2017, 2018 Carlo Zancanaro@*
46 Copyright @copyright{} 2017 Thomas Danckaert@*
47 Copyright @copyright{} 2017 humanitiesNerd@*
48 Copyright @copyright{} 2017 Christopher Allan Webber@*
49 Copyright @copyright{} 2017, 2018, 2019, 2020 Marius Bakke@*
50 Copyright @copyright{} 2017, 2019, 2020 Hartmut Goebel@*
51 Copyright @copyright{} 2017, 2019, 2020 Maxim Cournoyer@*
52 Copyright @copyright{} 2017, 2018, 2019, 2020 Tobias Geerinckx-Rice@*
53 Copyright @copyright{} 2017 George Clemmer@*
54 Copyright @copyright{} 2017 Andy Wingo@*
55 Copyright @copyright{} 2017, 2018, 2019, 2020 Arun Isaac@*
56 Copyright @copyright{} 2017 nee@*
57 Copyright @copyright{} 2018 Rutger Helling@*
58 Copyright @copyright{} 2018 Oleg Pykhalov@*
59 Copyright @copyright{} 2018 Mike Gerwitz@*
60 Copyright @copyright{} 2018 Pierre-Antoine Rouby@*
61 Copyright @copyright{} 2018, 2019 Gábor Boskovits@*
62 Copyright @copyright{} 2018, 2019, 2020 Florian Pelz@*
63 Copyright @copyright{} 2018 Laura Lazzati@*
64 Copyright @copyright{} 2018 Alex Vong@*
65 Copyright @copyright{} 2019 Josh Holland@*
66 Copyright @copyright{} 2019, 2020 Diego Nicola Barbato@*
67 Copyright @copyright{} 2019 Ivan Petkov@*
68 Copyright @copyright{} 2019 Jakob L. Kreuze@*
69 Copyright @copyright{} 2019 Kyle Andrews@*
70 Copyright @copyright{} 2019 Alex Griffin@*
71 Copyright @copyright{} 2019, 2020 Guillaume Le Vaillant@*
72 Copyright @copyright{} 2020 Leo Prikler@*
73 Copyright @copyright{} 2019, 2020 Simon Tournier@*
74 Copyright @copyright{} 2020 Wiktor Żelazny@*
75 Copyright @copyright{} 2020 Damien Cassou@*
76 Copyright @copyright{} 2020 Jakub Kądziołka@*
77 Copyright @copyright{} 2020 Jack Hill@*
78 Copyright @copyright{} 2020 Naga Malleswari@*
79 Copyright @copyright{} 2020 Brice Waegeneire@*
80 Copyright @copyright{} 2020 R Veera Kumar@*
81 Copyright @copyright{} 2020 Pierre Langlois@*
82 Copyright @copyright{} 2020 pinoaffe@*
83 Copyright @copyright{} 2020 André Batista@*
84 Copyright @copyright{} 2020 Alexandru-Sergiu Marton@*
85 Copyright @copyright{} 2020 raingloom@*
86 Copyright @copyright{} 2020 Daniel Brooks@*
87 Copyright @copyright{} 2020 John Soo@*
89 Permission is granted to copy, distribute and/or modify this document
90 under the terms of the GNU Free Documentation License, Version 1.3 or
91 any later version published by the Free Software Foundation; with no
92 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
93 copy of the license is included in the section entitled ``GNU Free
94 Documentation License''.
97 @dircategory System administration
99 * Guix: (guix). Manage installed software and system configuration.
100 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
101 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
102 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
103 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
104 * guix deploy: (guix)Invoking guix deploy. Manage operating system configurations for remote hosts.
107 @dircategory Software development
109 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
110 * guix build: (guix)Invoking guix build. Building packages.
111 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
115 @title GNU Guix Reference Manual
116 @subtitle Using the GNU Guix Functional Package Manager
117 @author The GNU Guix Developers
120 @vskip 0pt plus 1filll
121 Edition @value{EDITION} @*
129 @c *********************************************************************
133 This document describes GNU Guix version @value{VERSION}, a functional
134 package management tool written for the GNU system.
136 @c TRANSLATORS: You can replace the following paragraph with information on
137 @c how to join your own translation team and how to report issues with the
139 This manual is also available in Simplified Chinese (@pxref{Top,,, guix.zh_CN,
140 GNU Guix参考手册}), French (@pxref{Top,,, guix.fr, Manuel de référence de GNU
141 Guix}), German (@pxref{Top,,, guix.de, Referenzhandbuch zu GNU Guix}),
142 Spanish (@pxref{Top,,, guix.es, Manual de referencia de GNU Guix}), and
143 Russian (@pxref{Top,,, guix.ru, Руководство GNU Guix}). If you
144 would like to translate it in your native language, consider joining the
145 @uref{https://translationproject.org/domain/guix-manual.html, Translation
149 * Introduction:: What is Guix about?
150 * Installation:: Installing Guix.
151 * System Installation:: Installing the whole operating system.
152 * Getting Started:: Your first steps.
153 * Package Management:: Package installation, upgrade, etc.
154 * Channels:: Customizing the package collection.
155 * Development:: Guix-aided software development.
156 * Programming Interface:: Using Guix in Scheme.
157 * Utilities:: Package management commands.
158 * System Configuration:: Configuring the operating system.
159 * Documentation:: Browsing software user manuals.
160 * Installing Debugging Files:: Feeding the debugger.
161 * Security Updates:: Deploying security fixes quickly.
162 * Bootstrapping:: GNU/Linux built from scratch.
163 * Porting:: Targeting another platform or kernel.
164 * Contributing:: Your help needed!
166 * Acknowledgments:: Thanks!
167 * GNU Free Documentation License:: The license of this manual.
168 * Concept Index:: Concepts.
169 * Programming Index:: Data types, functions, and variables.
172 --- The Detailed Node Listing ---
176 * Managing Software the Guix Way:: What's special.
177 * GNU Distribution:: The packages and tools.
181 * Binary Installation:: Getting Guix running in no time!
182 * Requirements:: Software needed to build and run Guix.
183 * Running the Test Suite:: Testing Guix.
184 * Setting Up the Daemon:: Preparing the build daemon's environment.
185 * Invoking guix-daemon:: Running the build daemon.
186 * Application Setup:: Application-specific setup.
187 * Upgrading Guix:: Upgrading Guix and its build daemon.
189 Setting Up the Daemon
191 * Build Environment Setup:: Preparing the isolated build environment.
192 * Daemon Offload Setup:: Offloading builds to remote machines.
193 * SELinux Support:: Using an SELinux policy for the daemon.
197 * Limitations:: What you can expect.
198 * Hardware Considerations:: Supported hardware.
199 * USB Stick and DVD Installation:: Preparing the installation medium.
200 * Preparing for Installation:: Networking, partitioning, etc.
201 * Guided Graphical Installation:: Easy graphical installation.
202 * Manual Installation:: Manual installation for wizards.
203 * After System Installation:: When installation succeeded.
204 * Installing Guix in a VM:: Guix System playground.
205 * Building the Installation Image:: How this comes to be.
209 * Keyboard Layout and Networking and Partitioning:: Initial setup.
210 * Proceeding with the Installation:: Installing.
214 * Features:: How Guix will make your life brighter.
215 * Invoking guix package:: Package installation, removal, etc.
216 * Substitutes:: Downloading pre-built binaries.
217 * Packages with Multiple Outputs:: Single source package, multiple outputs.
218 * Invoking guix gc:: Running the garbage collector.
219 * Invoking guix pull:: Fetching the latest Guix and distribution.
220 * Invoking guix time-machine:: Running an older revision of Guix.
221 * Inferiors:: Interacting with another revision of Guix.
222 * Invoking guix describe:: Display information about your Guix revision.
223 * Invoking guix archive:: Exporting and importing store files.
227 * Official Substitute Server:: One particular source of substitutes.
228 * Substitute Server Authorization:: How to enable or disable substitutes.
229 * Getting Substitutes from Other Servers:: Substitute diversity.
230 * Substitute Authentication:: How Guix verifies substitutes.
231 * Proxy Settings:: How to get substitutes via proxy.
232 * Substitution Failure:: What happens when substitution fails.
233 * On Trusting Binaries:: How can you trust that binary blob?
237 * Specifying Additional Channels:: Extending the package collection.
238 * Using a Custom Guix Channel:: Using a customized Guix.
239 * Replicating Guix:: Running the @emph{exact same} Guix.
240 * Channel Authentication:: How Guix verifies what it fetches.
241 * Creating a Channel:: How to write your custom channel.
242 * Package Modules in a Sub-directory:: Specifying the channel's package modules location.
243 * Declaring Channel Dependencies:: How to depend on other channels.
244 * Specifying Channel Authorizations:: Defining channel authors authorizations.
245 * Primary URL:: Distinguishing mirror to original.
246 * Writing Channel News:: Communicating information to channel's users.
250 * Invoking guix environment:: Setting up development environments.
251 * Invoking guix pack:: Creating software bundles.
252 * The GCC toolchain:: Working with languages supported by GCC.
253 * Invoking guix git authenticate:: Authenticating Git repositories.
255 Programming Interface
257 * Package Modules:: Packages from the programmer's viewpoint.
258 * Defining Packages:: Defining new packages.
259 * Defining Package Variants:: Customizing packages.
260 * Build Systems:: Specifying how packages are built.
261 * Build Phases:: Phases of the build process of a package.
262 * Build Utilities:: Helpers for your package definitions and more.
263 * The Store:: Manipulating the package store.
264 * Derivations:: Low-level interface to package derivations.
265 * The Store Monad:: Purely functional interface to the store.
266 * G-Expressions:: Manipulating build expressions.
267 * Invoking guix repl:: Programming Guix in Guile.
271 * package Reference:: The package data type.
272 * origin Reference:: The origin data type.
276 * Invoking guix build:: Building packages from the command line.
277 * Invoking guix edit:: Editing package definitions.
278 * Invoking guix download:: Downloading a file and printing its hash.
279 * Invoking guix hash:: Computing the cryptographic hash of a file.
280 * Invoking guix import:: Importing package definitions.
281 * Invoking guix refresh:: Updating package definitions.
282 * Invoking guix lint:: Finding errors in package definitions.
283 * Invoking guix size:: Profiling disk usage.
284 * Invoking guix graph:: Visualizing the graph of packages.
285 * Invoking guix publish:: Sharing substitutes.
286 * Invoking guix challenge:: Challenging substitute servers.
287 * Invoking guix copy:: Copying to and from a remote store.
288 * Invoking guix container:: Process isolation.
289 * Invoking guix weather:: Assessing substitute availability.
290 * Invoking guix processes:: Listing client processes.
292 Invoking @command{guix build}
294 * Common Build Options:: Build options for most commands.
295 * Package Transformation Options:: Creating variants of packages.
296 * Additional Build Options:: Options specific to 'guix build'.
297 * Debugging Build Failures:: Real life packaging experience.
301 * Using the Configuration System:: Customizing your GNU system.
302 * operating-system Reference:: Detail of operating-system declarations.
303 * File Systems:: Configuring file system mounts.
304 * Mapped Devices:: Block device extra processing.
305 * User Accounts:: Specifying user accounts.
306 * Keyboard Layout:: How the system interprets key strokes.
307 * Locales:: Language and cultural convention settings.
308 * Services:: Specifying system services.
309 * Setuid Programs:: Programs running with root privileges.
310 * X.509 Certificates:: Authenticating HTTPS servers.
311 * Name Service Switch:: Configuring libc's name service switch.
312 * Initial RAM Disk:: Linux-Libre bootstrapping.
313 * Bootloader Configuration:: Configuring the boot loader.
314 * Invoking guix system:: Instantiating a system configuration.
315 * Invoking guix deploy:: Deploying a system configuration to a remote host.
316 * Running Guix in a VM:: How to run Guix System in a virtual machine.
317 * Defining Services:: Adding new service definitions.
321 * Base Services:: Essential system services.
322 * Scheduled Job Execution:: The mcron service.
323 * Log Rotation:: The rottlog service.
324 * Networking Services:: Network setup, SSH daemon, etc.
325 * Unattended Upgrades:: Automated system upgrades.
326 * X Window:: Graphical display.
327 * Printing Services:: Local and remote printer support.
328 * Desktop Services:: D-Bus and desktop services.
329 * Sound Services:: ALSA and Pulseaudio services.
330 * Database Services:: SQL databases, key-value stores, etc.
331 * Mail Services:: IMAP, POP3, SMTP, and all that.
332 * Messaging Services:: Messaging services.
333 * Telephony Services:: Telephony services.
334 * Monitoring Services:: Monitoring services.
335 * Kerberos Services:: Kerberos services.
336 * LDAP Services:: LDAP services.
337 * Web Services:: Web servers.
338 * Certificate Services:: TLS certificates via Let's Encrypt.
339 * DNS Services:: DNS daemons.
340 * VPN Services:: VPN daemons.
341 * Network File System:: NFS related services.
342 * Continuous Integration:: The Cuirass service.
343 * Power Management Services:: Extending battery life.
344 * Audio Services:: The MPD.
345 * Virtualization Services:: Virtualization services.
346 * Version Control Services:: Providing remote access to Git repositories.
347 * Game Services:: Game servers.
348 * PAM Mount Service:: Service to mount volumes when logging in.
349 * Guix Services:: Services relating specifically to Guix.
350 * Linux Services:: Services tied to the Linux kernel.
351 * Hurd Services:: Services specific for a Hurd System.
352 * Miscellaneous Services:: Other services.
356 * Service Composition:: The model for composing services.
357 * Service Types and Services:: Types and services.
358 * Service Reference:: API reference.
359 * Shepherd Services:: A particular type of service.
361 Installing Debugging Files
363 * Separate Debug Info:: Installing 'debug' outputs.
364 * Rebuilding Debug Info:: Building missing debug info.
368 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
369 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
374 @c *********************************************************************
376 @chapter Introduction
379 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
380 using the international phonetic alphabet (IPA).} is a package
381 management tool for and distribution of the GNU system.
382 Guix makes it easy for unprivileged
383 users to install, upgrade, or remove software packages, to roll back to a
384 previous package set, to build packages from source, and generally
385 assists with the creation and maintenance of software environments.
388 @cindex GuixSD, now Guix System
389 @cindex Guix System Distribution, now Guix System
390 You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
391 complements the available tools without interference (@pxref{Installation}),
392 or you can use it as a standalone operating system distribution,
393 @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
394 System Distribution'' or ``GuixSD''. We now consider it makes more sense to
395 group everything under the ``Guix'' banner since, after all, Guix System is
396 readily available through the @command{guix system} command, even if you're
397 using a different distro underneath!}. @xref{GNU Distribution}.
400 * Managing Software the Guix Way:: What's special.
401 * GNU Distribution:: The packages and tools.
404 @node Managing Software the Guix Way
405 @section Managing Software the Guix Way
407 @cindex user interfaces
408 Guix provides a command-line package management interface
409 (@pxref{Package Management}), tools to help with software development
410 (@pxref{Development}), command-line utilities for more advanced usage
411 (@pxref{Utilities}), as well as Scheme programming interfaces
412 (@pxref{Programming Interface}).
414 Its @dfn{build daemon} is responsible for building packages on behalf of
415 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
416 binaries from authorized sources (@pxref{Substitutes}).
418 @cindex extensibility of the distribution
419 @cindex customization, of packages
420 Guix includes package definitions for many GNU and non-GNU packages, all
421 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
422 user's computing freedom}. It is @emph{extensible}: users can write
423 their own package definitions (@pxref{Defining Packages}) and make them
424 available as independent package modules (@pxref{Package Modules}). It
425 is also @emph{customizable}: users can @emph{derive} specialized package
426 definitions from existing ones, including from the command line
427 (@pxref{Package Transformation Options}).
429 @cindex functional package management
431 Under the hood, Guix implements the @dfn{functional package management}
432 discipline pioneered by Nix (@pxref{Acknowledgments}).
433 In Guix, the package build and installation process is seen
434 as a @emph{function}, in the mathematical sense. That function takes inputs,
435 such as build scripts, a compiler, and libraries, and
436 returns an installed package. As a pure function, its result depends
437 solely on its inputs---for instance, it cannot refer to software or
438 scripts that were not explicitly passed as inputs. A build function
439 always produces the same result when passed a given set of inputs. It
440 cannot alter the environment of the running system in
441 any way; for instance, it cannot create, modify, or delete files outside
442 of its build and installation directories. This is achieved by running
443 build processes in isolated environments (or @dfn{containers}), where only their
444 explicit inputs are visible.
447 The result of package build functions is @dfn{cached} in the file
448 system, in a special directory called @dfn{the store} (@pxref{The
449 Store}). Each package is installed in a directory of its own in the
450 store---by default under @file{/gnu/store}. The directory name contains
451 a hash of all the inputs used to build that package; thus, changing an
452 input yields a different directory name.
454 This approach is the foundation for the salient features of Guix: support
455 for transactional package upgrade and rollback, per-user installation, and
456 garbage collection of packages (@pxref{Features}).
459 @node GNU Distribution
460 @section GNU Distribution
463 Guix comes with a distribution of the GNU system consisting entirely of
464 free software@footnote{The term ``free'' here refers to the
465 @url{https://www.gnu.org/philosophy/free-sw.html,freedom provided to
466 users of that software}.}. The
467 distribution can be installed on its own (@pxref{System Installation}),
468 but it is also possible to install Guix as a package manager on top of
469 an installed GNU/Linux system (@pxref{Installation}). When we need to
470 distinguish between the two, we refer to the standalone distribution as
473 The distribution provides core GNU packages such as GNU libc, GCC, and
474 Binutils, as well as many GNU and non-GNU applications. The complete
475 list of available packages can be browsed
476 @url{https://www.gnu.org/software/guix/packages,on-line} or by
477 running @command{guix package} (@pxref{Invoking guix package}):
480 guix package --list-available
483 Our goal is to provide a practical 100% free software distribution of
484 Linux-based and other variants of GNU, with a focus on the promotion and
485 tight integration of GNU components, and an emphasis on programs and
486 tools that help users exert that freedom.
488 Packages are currently available on the following platforms:
493 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel.
496 Intel 32-bit architecture (IA32), Linux-Libre kernel.
499 ARMv7-A architecture with hard float, Thumb-2 and NEON,
500 using the EABI hard-float application binary interface (ABI),
501 and Linux-Libre kernel.
504 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel.
507 @uref{https://hurd.gnu.org, GNU/Hurd} on the Intel 32-bit architecture
510 This configuration is experimental and under development. The easiest
511 way for you to give it a try is by setting up an instance of
512 @code{hurd-vm-service-type} on your GNU/Linux machine
513 (@pxref{transparent-emulation-qemu, @code{hurd-vm-service-type}}).
514 @xref{Contributing}, on how to help!
516 @item mips64el-linux (deprecated)
517 little-endian 64-bit MIPS processors, specifically the Loongson series,
518 n32 ABI, and Linux-Libre kernel. This configuration is no longer fully
519 supported; in particular, there is no ongoing work to ensure that this
520 architecture still works. Should someone decide they wish to revive this
521 architecture then the code is still available.
525 With Guix@tie{}System, you @emph{declare} all aspects of the operating system
526 configuration and Guix takes care of instantiating the configuration in a
527 transactional, reproducible, and stateless fashion (@pxref{System
528 Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
529 initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
530 Manual}), the well-known GNU utilities and tool chain, as well as the
531 graphical environment or system services of your choice.
533 Guix System is available on all the above platforms except
534 @code{mips64el-linux}.
537 For information on porting to other architectures or kernels,
540 Building this distribution is a cooperative effort, and you are invited
541 to join! @xref{Contributing}, for information about how you can help.
544 @c *********************************************************************
546 @chapter Installation
548 @cindex installing Guix
551 We recommend the use of this
552 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
553 shell installer script} to install Guix on top of a running GNU/Linux system,
554 thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
555 with the installation of the package manager, which can be done on top of a
556 running GNU/Linux system. If, instead, you want to install the complete GNU
557 operating system, @pxref{System Installation}.} The script automates the
558 download, installation, and initial configuration of Guix. It should be run
562 @cindex foreign distro
563 @cindex directories related to foreign distro
564 When installed on a foreign distro, GNU@tie{}Guix complements the available
565 tools without interference. Its data lives exclusively in two directories,
566 usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
567 such as @file{/etc}, are left untouched.
569 Once installed, Guix can be updated by running @command{guix pull}
570 (@pxref{Invoking guix pull}).
572 If you prefer to perform the installation steps manually or want to tweak
573 them, you may find the following subsections useful. They describe the
574 software requirements of Guix, as well as how to install it manually and get
578 * Binary Installation:: Getting Guix running in no time!
579 * Requirements:: Software needed to build and run Guix.
580 * Running the Test Suite:: Testing Guix.
581 * Setting Up the Daemon:: Preparing the build daemon's environment.
582 * Invoking guix-daemon:: Running the build daemon.
583 * Application Setup:: Application-specific setup.
584 * Upgrading Guix:: Upgrading Guix and its build daemon.
587 @node Binary Installation
588 @section Binary Installation
590 @cindex installing Guix from binaries
591 @cindex installer script
592 This section describes how to install Guix on an arbitrary system from a
593 self-contained tarball providing binaries for Guix and for all its
594 dependencies. This is often quicker than installing from source, which
595 is described in the next sections. The only requirement is to have
598 @c Note duplicated from the ``Installation'' node.
600 We recommend the use of this
601 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
602 shell installer script}. The script automates the download, installation, and
603 initial configuration steps described below. It should be run as the root
604 user. As root, you can thus run this:
608 wget https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh
609 chmod +x guix-install.sh
613 When you're done, @pxref{Application Setup} for extra configuration you
614 might need, and @ref{Getting Started} for your first steps!
617 Installing goes along these lines:
621 @cindex downloading Guix binary
622 Download the binary tarball from
623 @indicateurl{@value{BASE-URL}/guix-binary-@value{VERSION}.x86_64-linux.tar.xz},
624 where @code{x86_64-linux} can be replaced with @code{i686-linux} for an
625 @code{i686} (32-bits) machine already running the kernel Linux, and so on
626 (@pxref{GNU Distribution}).
628 @c The following is somewhat duplicated in ``System Installation''.
629 Make sure to download the associated @file{.sig} file and to verify the
630 authenticity of the tarball against it, along these lines:
633 $ wget @value{BASE-URL}/guix-binary-@value{VERSION}.x86_64-linux.tar.xz.sig
634 $ gpg --verify guix-binary-@value{VERSION}.x86_64-linux.tar.xz.sig
637 If that command fails because you do not have the required public key,
638 then run this command to import it:
641 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
642 -qO - | gpg --import -
646 and rerun the @code{gpg --verify} command.
648 Take note that a warning like ``This key is not certified with a trusted
649 signature!'' is normal.
651 @c end authentication part
654 Now, you need to become the @code{root} user. Depending on your distribution,
655 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
659 # tar --warning=no-timestamp -xf \
660 /path/to/guix-binary-@value{VERSION}.x86_64-linux.tar.xz
661 # mv var/guix /var/ && mv gnu /
664 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
665 The latter contains a ready-to-use profile for @code{root} (see next
668 Do @emph{not} unpack the tarball on a working Guix system since that
669 would overwrite its own essential files.
671 The @option{--warning=no-timestamp} option makes sure GNU@tie{}tar does
672 not emit warnings about ``implausibly old time stamps'' (such
673 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
675 They stem from the fact that all the
676 files in the archive have their modification time set to 1 (which
677 means January 1st, 1970). This is done on purpose to make sure the
678 archive content is independent of its creation time, thus making it
682 Make the profile available under @file{~root/.config/guix/current}, which is
683 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
686 # mkdir -p ~root/.config/guix
687 # ln -sf /var/guix/profiles/per-user/root/current-guix \
688 ~root/.config/guix/current
691 Source @file{etc/profile} to augment @env{PATH} and other relevant
692 environment variables:
695 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
696 source $GUIX_PROFILE/etc/profile
700 Create the group and user accounts for build users as explained below
701 (@pxref{Build Environment Setup}).
704 Run the daemon, and set it to automatically start on boot.
706 If your host distro uses the systemd init system, this can be achieved
709 @c Versions of systemd that supported symlinked service files are not
710 @c yet widely deployed, so we should suggest that users copy the service
713 @c See this thread for more information:
714 @c https://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
717 # cp ~root/.config/guix/current/lib/systemd/system/gnu-store.mount \
718 ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
720 # systemctl enable --now gnu-store.mount guix-daemon
723 If your host distro uses the Upstart init system:
726 # initctl reload-configuration
727 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
732 Otherwise, you can still start the daemon manually with:
735 # ~root/.config/guix/current/bin/guix-daemon \
736 --build-users-group=guixbuild
740 Make the @command{guix} command available to other users on the machine,
744 # mkdir -p /usr/local/bin
746 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
749 It is also a good idea to make the Info version of this manual available
753 # mkdir -p /usr/local/share/info
754 # cd /usr/local/share/info
755 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
759 That way, assuming @file{/usr/local/share/info} is in the search path,
760 running @command{info guix} will open this manual (@pxref{Other Info
761 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
765 @cindex substitutes, authorization thereof
766 To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
767 (@pxref{Substitutes}), authorize them:
770 # guix archive --authorize < \
771 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
775 Each user may need to perform a few additional steps to make their Guix
776 environment ready for use, @pxref{Application Setup}.
779 Voilà, the installation is complete!
781 You can confirm that Guix is working by installing a sample package into
788 The binary installation tarball can be (re)produced and verified simply
789 by running the following command in the Guix source tree:
792 make guix-binary.@var{system}.tar.xz
796 ...@: which, in turn, runs:
799 guix pack -s @var{system} --localstatedir \
800 --profile-name=current-guix guix
803 @xref{Invoking guix pack}, for more info on this handy tool.
806 @section Requirements
808 This section lists requirements when building Guix from source. The
809 build procedure for Guix is the same as for other GNU software, and is
810 not covered here. Please see the files @file{README} and @file{INSTALL}
811 in the Guix source tree for additional details.
813 @cindex official website
814 GNU Guix is available for download from its website at
815 @url{https://www.gnu.org/software/guix/}.
817 GNU Guix depends on the following packages:
820 @item @url{https://gnu.org/software/guile/, GNU Guile}, version 3.0.x or
822 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
825 @uref{https://gnutls.org/, GnuTLS}, specifically its Guile bindings
826 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
827 Guile,, gnutls-guile, GnuTLS-Guile});
829 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
831 @item @uref{https://notabug.org/guile-zlib/guile-zlib, Guile-zlib};
832 @item @uref{https://notabug.org/guile-lzlib/guile-lzlib, Guile-lzlib};
833 @item @uref{https://www.nongnu.org/guile-avahi/, Guile-Avahi};
835 @c FIXME: Specify a version number once a release has been made.
836 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, version 0.3.0
838 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON}
840 @item @url{https://www.gnu.org/software/make/, GNU Make}.
843 The following dependencies are optional:
847 @c Note: We need at least 0.13.0 for #:nodelay.
848 Support for build offloading (@pxref{Daemon Offload Setup}) and
849 @command{guix copy} (@pxref{Invoking guix copy}) depends on
850 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
851 version 0.13.0 or later.
854 @uref{https://ngyro.com/software/guile-semver.html, Guile-Semver} for
855 the @code{crate} importer (@pxref{Invoking guix import}).
858 When @url{http://www.bzip.org, libbz2} is available,
859 @command{guix-daemon} can use it to compress build logs.
862 Unless @option{--disable-daemon} was passed to @command{configure}, the
863 following packages are also needed:
866 @item @url{https://gnupg.org/, GNU libgcrypt};
867 @item @url{https://sqlite.org, SQLite 3};
868 @item @url{https://gcc.gnu.org, GCC's g++}, with support for the
872 @cindex state directory
873 When configuring Guix on a system that already has a Guix installation,
874 be sure to specify the same state directory as the existing installation
875 using the @option{--localstatedir} option of the @command{configure}
876 script (@pxref{Directory Variables, @code{localstatedir},, standards,
877 GNU Coding Standards}). Usually, this @var{localstatedir} option is
878 set to the value @file{/var}. The @command{configure} script protects
879 against unintended misconfiguration of @var{localstatedir} so you do not
880 inadvertently corrupt your store (@pxref{The Store}).
882 @node Running the Test Suite
883 @section Running the Test Suite
886 After a successful @command{configure} and @code{make} run, it is a good
887 idea to run the test suite. It can help catch issues with the setup or
888 environment, or bugs in Guix itself---and really, reporting test
889 failures is a good way to help improve the software. To run the test
896 Test cases can run in parallel: you can use the @code{-j} option of
897 GNU@tie{}make to speed things up. The first run may take a few minutes
898 on a recent machine; subsequent runs will be faster because the store
899 that is created for test purposes will already have various things in
902 It is also possible to run a subset of the tests by defining the
903 @code{TESTS} makefile variable as in this example:
906 make check TESTS="tests/store.scm tests/cpio.scm"
909 By default, tests results are displayed at a file level. In order to
910 see the details of every individual test cases, it is possible to define
911 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
914 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
917 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
918 @file{test-suite.log} file. Please specify the Guix version being used
919 as well as version numbers of the dependencies (@pxref{Requirements}) in
922 Guix also comes with a whole-system test suite that tests complete
923 Guix System instances. It can only run on systems where
924 Guix is already installed, using:
931 or, again, by defining @code{TESTS} to select a subset of tests to run:
934 make check-system TESTS="basic mcron"
937 These system tests are defined in the @code{(gnu tests @dots{})}
938 modules. They work by running the operating systems under test with
939 lightweight instrumentation in a virtual machine (VM). They can be
940 computationally intensive or rather cheap, depending on whether
941 substitutes are available for their dependencies (@pxref{Substitutes}).
942 Some of them require a lot of storage space to hold VM images.
944 Again in case of test failures, please send @email{bug-guix@@gnu.org}
947 @node Setting Up the Daemon
948 @section Setting Up the Daemon
951 Operations such as building a package or running the garbage collector
952 are all performed by a specialized process, the @dfn{build daemon}, on
953 behalf of clients. Only the daemon may access the store and its
954 associated database. Thus, any operation that manipulates the store
955 goes through the daemon. For instance, command-line tools such as
956 @command{guix package} and @command{guix build} communicate with the
957 daemon (@i{via} remote procedure calls) to instruct it what to do.
959 The following sections explain how to prepare the build daemon's
960 environment. See also @ref{Substitutes}, for information on how to allow
961 the daemon to download pre-built binaries.
964 * Build Environment Setup:: Preparing the isolated build environment.
965 * Daemon Offload Setup:: Offloading builds to remote machines.
966 * SELinux Support:: Using an SELinux policy for the daemon.
969 @node Build Environment Setup
970 @subsection Build Environment Setup
972 @cindex build environment
973 In a standard multi-user setup, Guix and its daemon---the
974 @command{guix-daemon} program---are installed by the system
975 administrator; @file{/gnu/store} is owned by @code{root} and
976 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
977 Guix tools to build packages or otherwise access the store, and the
978 daemon will do it on their behalf, ensuring that the store is kept in a
979 consistent state, and allowing built packages to be shared among users.
982 When @command{guix-daemon} runs as @code{root}, you may not want package
983 build processes themselves to run as @code{root} too, for obvious
984 security reasons. To avoid that, a special pool of @dfn{build users}
985 should be created for use by build processes started by the daemon.
986 These build users need not have a shell and a home directory: they will
987 just be used when the daemon drops @code{root} privileges in build
988 processes. Having several such users allows the daemon to launch
989 distinct build processes under separate UIDs, which guarantees that they
990 do not interfere with each other---an essential feature since builds are
991 regarded as pure functions (@pxref{Introduction}).
993 On a GNU/Linux system, a build user pool may be created like this (using
994 Bash syntax and the @code{shadow} commands):
996 @c See https://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
997 @c for why `-G' is needed.
999 # groupadd --system guixbuild
1000 # for i in `seq -w 1 10`;
1002 useradd -g guixbuild -G guixbuild \
1003 -d /var/empty -s `which nologin` \
1004 -c "Guix build user $i" --system \
1010 The number of build users determines how many build jobs may run in
1011 parallel, as specified by the @option{--max-jobs} option
1012 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
1013 @command{guix system vm} and related commands, you may need to add the
1014 build users to the @code{kvm} group so they can access @file{/dev/kvm},
1015 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
1016 (@pxref{Invoking guix system}).
1018 The @code{guix-daemon} program may then be run as @code{root} with the
1019 following command@footnote{If your machine uses the systemd init system,
1020 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
1021 file in @file{/etc/systemd/system} will ensure that
1022 @command{guix-daemon} is automatically started. Similarly, if your
1023 machine uses the Upstart init system, drop the
1024 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
1025 file in @file{/etc/init}.}:
1028 # guix-daemon --build-users-group=guixbuild
1033 This way, the daemon starts build processes in a chroot, under one of
1034 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
1035 environment contains nothing but:
1037 @c Keep this list in sync with libstore/build.cc! -----------------------
1040 a minimal @code{/dev} directory, created mostly independently from the
1041 host @code{/dev}@footnote{``Mostly'', because while the set of files
1042 that appear in the chroot's @code{/dev} is fixed, most of these files
1043 can only be created if the host has them.};
1046 the @code{/proc} directory; it only shows the processes of the container
1047 since a separate PID name space is used;
1050 @file{/etc/passwd} with an entry for the current user and an entry for
1054 @file{/etc/group} with an entry for the user's group;
1057 @file{/etc/hosts} with an entry that maps @code{localhost} to
1061 a writable @file{/tmp} directory.
1064 You can influence the directory where the daemon stores build trees
1065 @i{via} the @env{TMPDIR} environment variable. However, the build tree
1066 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
1067 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
1068 This way, the value of @env{TMPDIR} does not leak inside build
1069 environments, which avoids discrepancies in cases where build processes
1070 capture the name of their build tree.
1074 The daemon also honors the @env{http_proxy} and @env{https_proxy}
1075 environment variables for HTTP and HTTPS downloads it performs, be it
1076 for fixed-output derivations (@pxref{Derivations}) or for substitutes
1077 (@pxref{Substitutes}).
1079 If you are installing Guix as an unprivileged user, it is still possible
1080 to run @command{guix-daemon} provided you pass @option{--disable-chroot}.
1081 However, build processes will not be isolated from one another, and not
1082 from the rest of the system. Thus, build processes may interfere with
1083 each other, and may access programs, libraries, and other files
1084 available on the system---making it much harder to view them as
1085 @emph{pure} functions.
1088 @node Daemon Offload Setup
1089 @subsection Using the Offload Facility
1093 When desired, the build daemon can @dfn{offload} derivation builds to
1094 other machines running Guix, using the @code{offload} @dfn{build
1095 hook}@footnote{This feature is available only when
1096 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1097 present.}. When that feature is enabled, a list of user-specified build
1098 machines is read from @file{/etc/guix/machines.scm}; every time a build
1099 is requested, for instance via @code{guix build}, the daemon attempts to
1100 offload it to one of the machines that satisfy the constraints of the
1101 derivation, in particular its system types---e.g., @code{x86_64-linux}.
1102 A single machine can have multiple system types, either because its
1103 architecture natively supports it, via emulation
1104 (@pxref{transparent-emulation-qemu, Transparent Emulation with QEMU}),
1105 or both. Missing prerequisites for the build are
1106 copied over SSH to the target machine, which then proceeds with the
1107 build; upon success the output(s) of the build are copied back to the
1108 initial machine. The offload facility comes with a basic scheduler that
1109 attempts to select the best machine. The best machine is chosen among
1110 the available machines based on criteria such as:
1114 The availability of a build slot. A build machine can have as many
1115 build slots (connections) as the value of the @code{parallel-builds}
1116 field of its @code{build-machine} object.
1119 Its relative speed, as defined via the @code{speed} field of its
1120 @code{build-machine} object.
1123 Its load. The normalized machine load must be lower than a threshold
1124 value, configurable via the @code{overload-threshold} field of its
1125 @code{build-machine} object.
1128 Disk space availability. More than a 100 MiB must be available.
1131 The @file{/etc/guix/machines.scm} file typically looks like this:
1134 (list (build-machine
1135 (name "eightysix.example.org")
1136 (systems (list "x86_64-linux" "i686-linux"))
1137 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1139 (speed 2.)) ;incredibly fast!
1142 (name "armeight.example.org")
1143 (systems (list "aarch64-linux"))
1144 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1147 (string-append (getenv "HOME")
1148 "/.ssh/identity-for-guix"))))
1152 In the example above we specify a list of two build machines, one for
1153 the @code{x86_64} and @code{i686} architectures and one for the
1154 @code{aarch64} architecture.
1156 In fact, this file is---not surprisingly!---a Scheme file that is
1157 evaluated when the @code{offload} hook is started. Its return value
1158 must be a list of @code{build-machine} objects. While this example
1159 shows a fixed list of build machines, one could imagine, say, using
1160 DNS-SD to return a list of potential build machines discovered in the
1161 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1162 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1165 @deftp {Data Type} build-machine
1166 This data type represents build machines to which the daemon may offload
1167 builds. The important fields are:
1172 The host name of the remote machine.
1175 The system types the remote machine supports---e.g., @code{(list
1176 "x86_64-linux" "i686-linux")}.
1179 The user account to use when connecting to the remote machine over SSH.
1180 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1181 allow non-interactive logins.
1184 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1185 This is used to authenticate the machine when we connect to it. It is a
1186 long string that looks like this:
1189 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1192 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1193 key can be found in a file such as
1194 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1196 If the machine is running the SSH daemon of GNU@tie{}lsh,
1197 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1198 similar file. It can be converted to the OpenSSH format using
1199 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1202 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1203 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1208 A number of optional fields may be specified:
1212 @item @code{port} (default: @code{22})
1213 Port number of SSH server on the machine.
1215 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1216 The SSH private key file to use when connecting to the machine, in
1217 OpenSSH format. This key must not be protected with a passphrase.
1219 Note that the default value is the private key @emph{of the root
1220 account}. Make sure it exists if you use the default.
1222 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1223 @itemx @code{compression-level} (default: @code{3})
1224 The SSH-level compression methods and compression level requested.
1226 Note that offloading relies on SSH compression to reduce bandwidth usage
1227 when transferring files to and from build machines.
1229 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1230 File name of the Unix-domain socket @command{guix-daemon} is listening
1233 @item @code{overload-threshold} (default: @code{0.6})
1234 The load threshold above which a potential offload machine is
1235 disregarded by the offload scheduler. The value roughly translates to
1236 the total processor usage of the build machine, ranging from 0.0 (0%) to
1237 1.0 (100%). It can also be disabled by setting
1238 @code{overload-threshold} to @code{#f}.
1240 @item @code{parallel-builds} (default: @code{1})
1241 The number of builds that may run in parallel on the machine.
1243 @item @code{speed} (default: @code{1.0})
1244 A ``relative speed factor''. The offload scheduler will tend to prefer
1245 machines with a higher speed factor.
1247 @item @code{features} (default: @code{'()})
1248 A list of strings denoting specific features supported by the machine.
1249 An example is @code{"kvm"} for machines that have the KVM Linux modules
1250 and corresponding hardware support. Derivations can request features by
1251 name, and they will be scheduled on matching build machines.
1256 The @command{guix} command must be in the search path on the build
1257 machines. You can check whether this is the case by running:
1260 ssh build-machine guix repl --version
1263 There is one last thing to do once @file{machines.scm} is in place. As
1264 explained above, when offloading, files are transferred back and forth
1265 between the machine stores. For this to work, you first need to
1266 generate a key pair on each machine to allow the daemon to export signed
1267 archives of files from the store (@pxref{Invoking guix archive}):
1270 # guix archive --generate-key
1274 Each build machine must authorize the key of the master machine so that
1275 it accepts store items it receives from the master:
1278 # guix archive --authorize < master-public-key.txt
1282 Likewise, the master machine must authorize the key of each build machine.
1284 All the fuss with keys is here to express pairwise mutual trust
1285 relations between the master and the build machines. Concretely, when
1286 the master receives files from a build machine (and @i{vice versa}), its
1287 build daemon can make sure they are genuine, have not been tampered
1288 with, and that they are signed by an authorized key.
1290 @cindex offload test
1291 To test whether your setup is operational, run this command on the
1298 This will attempt to connect to each of the build machines specified in
1299 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1300 available on each machine, attempt to export to the machine and import
1301 from it, and report any error in the process.
1303 If you want to test a different machine file, just specify it on the
1307 # guix offload test machines-qualif.scm
1310 Last, you can test the subset of the machines whose name matches a
1311 regular expression like this:
1314 # guix offload test machines.scm '\.gnu\.org$'
1317 @cindex offload status
1318 To display the current load of all build hosts, run this command on the
1322 # guix offload status
1326 @node SELinux Support
1327 @subsection SELinux Support
1329 @cindex SELinux, daemon policy
1330 @cindex mandatory access control, SELinux
1331 @cindex security, guix-daemon
1332 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1333 can be installed on a system where SELinux is enabled, in order to label
1334 Guix files and to specify the expected behavior of the daemon. Since
1335 Guix System does not provide an SELinux base policy, the daemon policy cannot
1336 be used on Guix System.
1338 @subsubsection Installing the SELinux policy
1339 @cindex SELinux, policy installation
1340 To install the policy run this command as root:
1343 semodule -i etc/guix-daemon.cil
1346 Then relabel the file system with @code{restorecon} or by a different
1347 mechanism provided by your system.
1349 Once the policy is installed, the file system has been relabeled, and
1350 the daemon has been restarted, it should be running in the
1351 @code{guix_daemon_t} context. You can confirm this with the following
1355 ps -Zax | grep guix-daemon
1358 Monitor the SELinux log files as you run a command like @code{guix build
1359 hello} to convince yourself that SELinux permits all necessary
1362 @subsubsection Limitations
1363 @cindex SELinux, limitations
1365 This policy is not perfect. Here is a list of limitations or quirks
1366 that should be considered when deploying the provided SELinux policy for
1371 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1372 operations involve contexts that have anything to do with
1373 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1374 but it would be preferrable to define socket rules for only this label.
1377 @code{guix gc} cannot access arbitrary links to profiles. By design,
1378 the file label of the destination of a symlink is independent of the
1379 file label of the link itself. Although all profiles under
1380 $localstatedir are labelled, the links to these profiles inherit the
1381 label of the directory they are in. For links in the user’s home
1382 directory this will be @code{user_home_t}. But for links from the root
1383 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1384 directory, etc, this won’t work. @code{guix gc} would be prevented from
1385 reading and following these links.
1388 The daemon’s feature to listen for TCP connections might no longer work.
1389 This might require extra rules, because SELinux treats network sockets
1390 differently from files.
1393 Currently all files with a name matching the regular expression
1394 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1395 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1396 that name in any profile would be permitted to run in the
1397 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1398 build a package that provides this executable and convince a user to
1399 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1400 At that point SELinux could not prevent it from accessing files that are
1401 allowed for processes in that domain.
1403 You will need to relabel the store directory after all upgrades to
1404 @file{guix-daemon}, such as after running @code{guix pull}. Assuming the
1405 store is in @file{/gnu}, you can do this with @code{restorecon -vR /gnu},
1406 or by other means provided by your operating system.
1408 We could generate a much more restrictive policy at installation time,
1409 so that only the @emph{exact} file name of the currently installed
1410 @code{guix-daemon} executable would be labelled with
1411 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1412 The downside is that root would have to install or upgrade the policy at
1413 installation time whenever the Guix package that provides the
1414 effectively running @code{guix-daemon} executable is upgraded.
1417 @node Invoking guix-daemon
1418 @section Invoking @command{guix-daemon}
1420 The @command{guix-daemon} program implements all the functionality to
1421 access the store. This includes launching build processes, running the
1422 garbage collector, querying the availability of a build result, etc. It
1423 is normally run as @code{root} like this:
1426 # guix-daemon --build-users-group=guixbuild
1430 For details on how to set it up, @pxref{Setting Up the Daemon}.
1433 @cindex container, build environment
1434 @cindex build environment
1435 @cindex reproducible builds
1436 By default, @command{guix-daemon} launches build processes under
1437 different UIDs, taken from the build group specified with
1438 @option{--build-users-group}. In addition, each build process is run in a
1439 chroot environment that only contains the subset of the store that the
1440 build process depends on, as specified by its derivation
1441 (@pxref{Programming Interface, derivation}), plus a set of specific
1442 system directories. By default, the latter contains @file{/dev} and
1443 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1444 @dfn{container}: in addition to having its own file system tree, it has
1445 a separate mount name space, its own PID name space, network name space,
1446 etc. This helps achieve reproducible builds (@pxref{Features}).
1448 When the daemon performs a build on behalf of the user, it creates a
1449 build directory under @file{/tmp} or under the directory specified by
1450 its @env{TMPDIR} environment variable. This directory is shared with
1451 the container for the duration of the build, though within the container,
1452 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1454 The build directory is automatically deleted upon completion, unless the
1455 build failed and the client specified @option{--keep-failed}
1456 (@pxref{Invoking guix build, @option{--keep-failed}}).
1458 The daemon listens for connections and spawns one sub-process for each session
1459 started by a client (one of the @command{guix} sub-commands). The
1460 @command{guix processes} command allows you to get an overview of the activity
1461 on your system by viewing each of the active sessions and clients.
1462 @xref{Invoking guix processes}, for more information.
1464 The following command-line options are supported:
1467 @item --build-users-group=@var{group}
1468 Take users from @var{group} to run build processes (@pxref{Setting Up
1469 the Daemon, build users}).
1471 @item --no-substitutes
1473 Do not use substitutes for build products. That is, always build things
1474 locally instead of allowing downloads of pre-built binaries
1475 (@pxref{Substitutes}).
1477 When the daemon runs with @option{--no-substitutes}, clients can still
1478 explicitly enable substitution @i{via} the @code{set-build-options}
1479 remote procedure call (@pxref{The Store}).
1481 @anchor{daemon-substitute-urls}
1482 @item --substitute-urls=@var{urls}
1483 Consider @var{urls} the default whitespace-separated list of substitute
1484 source URLs. When this option is omitted,
1485 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1487 This means that substitutes may be downloaded from @var{urls}, as long
1488 as they are signed by a trusted signature (@pxref{Substitutes}).
1490 @xref{Getting Substitutes from Other Servers}, for more information on
1491 how to configure the daemon to get substitutes from other servers.
1495 Do not use offload builds to other machines (@pxref{Daemon Offload
1496 Setup}). That is, always build things locally instead of offloading
1497 builds to remote machines.
1499 @item --cache-failures
1500 Cache build failures. By default, only successful builds are cached.
1502 When this option is used, @command{guix gc --list-failures} can be used
1503 to query the set of store items marked as failed; @command{guix gc
1504 --clear-failures} removes store items from the set of cached failures.
1505 @xref{Invoking guix gc}.
1507 @item --cores=@var{n}
1509 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1512 The default value is @code{0}, but it may be overridden by clients, such
1513 as the @option{--cores} option of @command{guix build} (@pxref{Invoking
1516 The effect is to define the @env{NIX_BUILD_CORES} environment variable
1517 in the build process, which can then use it to exploit internal
1518 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1520 @item --max-jobs=@var{n}
1522 Allow at most @var{n} build jobs in parallel. The default value is
1523 @code{1}. Setting it to @code{0} means that no builds will be performed
1524 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1525 Setup}), or simply fail.
1527 @item --max-silent-time=@var{seconds}
1528 When the build or substitution process remains silent for more than
1529 @var{seconds}, terminate it and report a build failure.
1531 The default value is @code{0}, which disables the timeout.
1533 The value specified here can be overridden by clients (@pxref{Common
1534 Build Options, @option{--max-silent-time}}).
1536 @item --timeout=@var{seconds}
1537 Likewise, when the build or substitution process lasts for more than
1538 @var{seconds}, terminate it and report a build failure.
1540 The default value is @code{0}, which disables the timeout.
1542 The value specified here can be overridden by clients (@pxref{Common
1543 Build Options, @option{--timeout}}).
1545 @item --rounds=@var{N}
1546 Build each derivation @var{n} times in a row, and raise an error if
1547 consecutive build results are not bit-for-bit identical. Note that this
1548 setting can be overridden by clients such as @command{guix build}
1549 (@pxref{Invoking guix build}).
1551 When used in conjunction with @option{--keep-failed}, the differing
1552 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1553 This makes it easy to look for differences between the two results.
1556 Produce debugging output.
1558 This is useful to debug daemon start-up issues, but then it may be
1559 overridden by clients, for example the @option{--verbosity} option of
1560 @command{guix build} (@pxref{Invoking guix build}).
1562 @item --chroot-directory=@var{dir}
1563 Add @var{dir} to the build chroot.
1565 Doing this may change the result of build processes---for instance if
1566 they use optional dependencies found in @var{dir} when it is available,
1567 and not otherwise. For that reason, it is not recommended to do so.
1568 Instead, make sure that each derivation declares all the inputs that it
1571 @item --disable-chroot
1572 Disable chroot builds.
1574 Using this option is not recommended since, again, it would allow build
1575 processes to gain access to undeclared dependencies. It is necessary,
1576 though, when @command{guix-daemon} is running under an unprivileged user
1579 @item --log-compression=@var{type}
1580 Compress build logs according to @var{type}, one of @code{gzip},
1581 @code{bzip2}, or @code{none}.
1583 Unless @option{--lose-logs} is used, all the build logs are kept in the
1584 @var{localstatedir}. To save space, the daemon automatically compresses
1585 them with Bzip2 by default.
1587 @item --discover[=yes|no]
1588 Whether to discover substitute servers on the local network using mDNS
1591 This feature is still experimental. However, here are a few
1596 It might be faster/less expensive than fetching from remote servers;
1598 There are no security risks, only genuine substitutes will be used
1599 (@pxref{Substitute Authentication});
1601 An attacker advertising @command{guix publish} on your LAN cannot serve
1602 you malicious binaries, but they can learn what software you’re
1605 Servers may serve substitute over HTTP, unencrypted, so anyone on the
1606 LAN can see what software you’re installing.
1609 It is also possible to enable or disable substitute server discovery at
1610 run-time by running:
1613 herd discover guix-daemon on
1614 herd discover guix-daemon off
1617 @item --disable-deduplication
1618 @cindex deduplication
1619 Disable automatic file ``deduplication'' in the store.
1621 By default, files added to the store are automatically ``deduplicated'':
1622 if a newly added file is identical to another one found in the store,
1623 the daemon makes the new file a hard link to the other file. This can
1624 noticeably reduce disk usage, at the expense of slightly increased
1625 input/output load at the end of a build process. This option disables
1628 @item --gc-keep-outputs[=yes|no]
1629 Tell whether the garbage collector (GC) must keep outputs of live
1633 @cindex garbage collector roots
1634 When set to @code{yes}, the GC will keep the outputs of any live
1635 derivation available in the store---the @file{.drv} files. The default
1636 is @code{no}, meaning that derivation outputs are kept only if they are
1637 reachable from a GC root. @xref{Invoking guix gc}, for more on GC
1640 @item --gc-keep-derivations[=yes|no]
1641 Tell whether the garbage collector (GC) must keep derivations
1642 corresponding to live outputs.
1644 When set to @code{yes}, as is the case by default, the GC keeps
1645 derivations---i.e., @file{.drv} files---as long as at least one of their
1646 outputs is live. This allows users to keep track of the origins of
1647 items in their store. Setting it to @code{no} saves a bit of disk
1650 In this way, setting @option{--gc-keep-derivations} to @code{yes} causes
1651 liveness to flow from outputs to derivations, and setting
1652 @option{--gc-keep-outputs} to @code{yes} causes liveness to flow from
1653 derivations to outputs. When both are set to @code{yes}, the effect is
1654 to keep all the build prerequisites (the sources, compiler, libraries,
1655 and other build-time tools) of live objects in the store, regardless of
1656 whether these prerequisites are reachable from a GC root. This is
1657 convenient for developers since it saves rebuilds or downloads.
1659 @item --impersonate-linux-2.6
1660 On Linux-based systems, impersonate Linux 2.6. This means that the
1661 kernel's @command{uname} system call will report 2.6 as the release number.
1663 This might be helpful to build programs that (usually wrongfully) depend
1664 on the kernel version number.
1667 Do not keep build logs. By default they are kept under
1668 @file{@var{localstatedir}/guix/log}.
1670 @item --system=@var{system}
1671 Assume @var{system} as the current system type. By default it is the
1672 architecture/kernel pair found at configure time, such as
1673 @code{x86_64-linux}.
1675 @item --listen=@var{endpoint}
1676 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1677 as the file name of a Unix-domain socket if it starts with
1678 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1679 host name or host name and port to listen to. Here are a few examples:
1682 @item --listen=/gnu/var/daemon
1683 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1684 creating it if needed.
1686 @item --listen=localhost
1687 @cindex daemon, remote access
1688 @cindex remote access to the daemon
1689 @cindex daemon, cluster setup
1690 @cindex clusters, daemon setup
1691 Listen for TCP connections on the network interface corresponding to
1692 @code{localhost}, on port 44146.
1694 @item --listen=128.0.0.42:1234
1695 Listen for TCP connections on the network interface corresponding to
1696 @code{128.0.0.42}, on port 1234.
1699 This option can be repeated multiple times, in which case
1700 @command{guix-daemon} accepts connections on all the specified
1701 endpoints. Users can tell client commands what endpoint to connect to
1702 by setting the @env{GUIX_DAEMON_SOCKET} environment variable
1703 (@pxref{The Store, @env{GUIX_DAEMON_SOCKET}}).
1706 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1707 @option{--listen=@var{host}} is suitable on local networks, such as
1708 clusters, where only trusted nodes may connect to the build daemon. In
1709 other cases where remote access to the daemon is needed, we recommend
1710 using Unix-domain sockets along with SSH.
1713 When @option{--listen} is omitted, @command{guix-daemon} listens for
1714 connections on the Unix-domain socket located at
1715 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1719 @node Application Setup
1720 @section Application Setup
1722 @cindex foreign distro
1723 When using Guix on top of GNU/Linux distribution other than Guix System---a
1724 so-called @dfn{foreign distro}---a few additional steps are needed to
1725 get everything in place. Here are some of them.
1729 @anchor{locales-and-locpath}
1730 @cindex locales, when not on Guix System
1732 @vindex GUIX_LOCPATH
1733 Packages installed @i{via} Guix will not use the locale data of the
1734 host system. Instead, you must first install one of the locale packages
1735 available with Guix and then define the @env{GUIX_LOCPATH} environment
1739 $ guix install glibc-locales
1740 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1743 Note that the @code{glibc-locales} package contains data for all the
1744 locales supported by the GNU@tie{}libc and weighs in at around
1745 917@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1746 limited to a few UTF-8 locales.
1748 The @env{GUIX_LOCPATH} variable plays a role similar to @env{LOCPATH}
1749 (@pxref{Locale Names, @env{LOCPATH},, libc, The GNU C Library Reference
1750 Manual}). There are two important differences though:
1754 @env{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1755 provided by foreign distros. Thus, using @env{GUIX_LOCPATH} allows you
1756 to make sure the programs of the foreign distro will not end up loading
1757 incompatible locale data.
1760 libc suffixes each entry of @env{GUIX_LOCPATH} with @code{/X.Y}, where
1761 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1762 should your Guix profile contain a mixture of programs linked against
1763 different libc version, each libc version will only try to load locale
1764 data in the right format.
1767 This is important because the locale data format used by different libc
1768 versions may be incompatible.
1770 @subsection Name Service Switch
1772 @cindex name service switch, glibc
1773 @cindex NSS (name service switch), glibc
1774 @cindex nscd (name service caching daemon)
1775 @cindex name service caching daemon (nscd)
1776 When using Guix on a foreign distro, we @emph{strongly recommend} that
1777 the system run the GNU C library's @dfn{name service cache daemon},
1778 @command{nscd}, which should be listening on the
1779 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1780 installed with Guix may fail to look up host names or user accounts, or
1781 may even crash. The next paragraphs explain why.
1783 @cindex @file{nsswitch.conf}
1784 The GNU C library implements a @dfn{name service switch} (NSS), which is
1785 an extensible mechanism for ``name lookups'' in general: host name
1786 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1787 The GNU C Library Reference Manual}).
1789 @cindex Network information service (NIS)
1790 @cindex NIS (Network information service)
1791 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1792 lookup implementations: for example, the @code{nss-mdns} plugin allow
1793 resolution of @code{.local} host names, the @code{nis} plugin allows
1794 user account lookup using the Network information service (NIS), and so
1795 on. These extra ``lookup services'' are configured system-wide in
1796 @file{/etc/nsswitch.conf}, and all the programs running on the system
1797 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1800 When they perform a name lookup---for instance by calling the
1801 @code{getaddrinfo} function in C---applications first try to connect to
1802 the nscd; on success, nscd performs name lookups on their behalf. If
1803 the nscd is not running, then they perform the name lookup by
1804 themselves, by loading the name lookup services into their own address
1805 space and running it. These name lookup services---the
1806 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1807 the host system's C library, rather than from the C library the
1808 application is linked against (the C library coming from Guix).
1810 And this is where the problem is: if your application is linked against
1811 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1812 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1813 likely crash or have its name lookups fail unexpectedly.
1815 Running @command{nscd} on the system, among other advantages, eliminates
1816 this binary incompatibility problem because those @code{libnss_*.so}
1817 files are loaded in the @command{nscd} process, not in applications
1820 @subsection X11 Fonts
1823 The majority of graphical applications use Fontconfig to locate and
1824 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1825 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1826 by default. Thus, to allow graphical applications installed with Guix
1827 to display fonts, you have to install fonts with Guix as well.
1828 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1829 @code{font-gnu-freefont}.
1831 @cindex @code{fc-cache}
1833 Once you have installed or removed fonts, or when you notice an
1834 application that does not find fonts, you may need to install Fontconfig
1835 and to force an update of its font cache by running:
1838 guix install fontconfig
1842 To display text written in Chinese languages, Japanese, or Korean in
1843 graphical applications, consider installing
1844 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1845 has multiple outputs, one per language family (@pxref{Packages with
1846 Multiple Outputs}). For instance, the following command installs fonts
1847 for Chinese languages:
1850 guix install font-adobe-source-han-sans:cn
1853 @cindex @code{xterm}
1854 Older programs such as @command{xterm} do not use Fontconfig and instead
1855 rely on server-side font rendering. Such programs require to specify a
1856 full name of a font using XLFD (X Logical Font Description), like this:
1859 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1862 To be able to use such full names for the TrueType fonts installed in
1863 your Guix profile, you need to extend the font path of the X server:
1865 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1866 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1868 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1871 @cindex @code{xlsfonts}
1872 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1873 to make sure your TrueType fonts are listed there.
1876 @subsection X.509 Certificates
1878 @cindex @code{nss-certs}
1879 The @code{nss-certs} package provides X.509 certificates, which allow
1880 programs to authenticate Web servers accessed over HTTPS.
1882 When using Guix on a foreign distro, you can install this package and
1883 define the relevant environment variables so that packages know where to
1884 look for certificates. @xref{X.509 Certificates}, for detailed
1887 @subsection Emacs Packages
1889 @cindex @code{emacs}
1890 When you install Emacs packages with Guix, the Elisp files are placed
1891 under the @file{share/emacs/site-lisp/} directory of the profile in
1892 which they are installed. The Elisp libraries are made available to
1893 Emacs through the @env{EMACSLOADPATH} environment variable, which is
1894 set when installing Emacs itself.
1896 Additionally, autoload definitions are automatically evaluated at the
1897 initialization of Emacs, by the Guix-specific
1898 @code{guix-emacs-autoload-packages} procedure. If, for some reason, you
1899 want to avoid auto-loading the Emacs packages installed with Guix, you
1900 can do so by running Emacs with the @option{--no-site-file} option
1901 (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1904 @node Upgrading Guix
1905 @section Upgrading Guix
1907 @cindex Upgrading Guix, on a foreign distro
1909 To upgrade Guix, run:
1915 @xref{Invoking guix pull}, for more information.
1917 @cindex upgrading Guix for the root user, on a foreign distro
1918 @cindex upgrading the Guix daemon, on a foreign distro
1919 @cindex @command{guix pull} for the root user, on a foreign distro
1921 On a foreign distro, you can upgrade the build daemon by running:
1928 followed by (assuming your distro uses the systemd service management
1932 systemctl restart guix-daemon.service
1935 On Guix System, upgrading the daemon is achieved by reconfiguring the
1936 system (@pxref{Invoking guix system, @code{guix system reconfigure}}).
1940 @c *********************************************************************
1941 @node System Installation
1942 @chapter System Installation
1944 @cindex installing Guix System
1945 @cindex Guix System, installation
1946 This section explains how to install Guix System
1947 on a machine. Guix, as a package manager, can
1948 also be installed on top of a running GNU/Linux system,
1949 @pxref{Installation}.
1953 @c This paragraph is for people reading this from tty2 of the
1954 @c installation image.
1955 You are reading this documentation with an Info reader. For details on
1956 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
1957 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
1958 Info}. Hit @kbd{l} afterwards to come back here.
1960 Alternatively, run @command{info info} in another tty to keep the manual
1966 * Limitations:: What you can expect.
1967 * Hardware Considerations:: Supported hardware.
1968 * USB Stick and DVD Installation:: Preparing the installation medium.
1969 * Preparing for Installation:: Networking, partitioning, etc.
1970 * Guided Graphical Installation:: Easy graphical installation.
1971 * Manual Installation:: Manual installation for wizards.
1972 * After System Installation:: When installation succeeded.
1973 * Installing Guix in a VM:: Guix System playground.
1974 * Building the Installation Image:: How this comes to be.
1978 @section Limitations
1980 We consider Guix System to be ready for a wide range of ``desktop'' and server
1981 use cases. The reliability guarantees it provides---transactional upgrades
1982 and rollbacks, reproducibility---make it a solid foundation.
1984 Nevertheless, before you proceed with the installation, be aware of the
1985 following noteworthy limitations applicable to version @value{VERSION}:
1989 More and more system services are provided (@pxref{Services}), but some
1993 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
1994 as well as a number of X11 window managers. However, KDE is currently
1998 More than a disclaimer, this is an invitation to report issues (and success
1999 stories!), and to join us in improving it. @xref{Contributing}, for more
2003 @node Hardware Considerations
2004 @section Hardware Considerations
2006 @cindex hardware support on Guix System
2007 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
2008 builds around the kernel Linux-libre, which means that only hardware for
2009 which free software drivers and firmware exist is supported. Nowadays,
2010 a wide range of off-the-shelf hardware is supported on
2011 GNU/Linux-libre---from keyboards to graphics cards to scanners and
2012 Ethernet controllers. Unfortunately, there are still areas where
2013 hardware vendors deny users control over their own computing, and such
2014 hardware is not supported on Guix System.
2016 @cindex WiFi, hardware support
2017 One of the main areas where free drivers or firmware are lacking is WiFi
2018 devices. WiFi devices known to work include those using Atheros chips
2019 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
2020 driver, and those using Broadcom/AirForce chips (BCM43xx with
2021 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
2022 Linux-libre driver. Free firmware exists for both and is available
2023 out-of-the-box on Guix System, as part of @code{%base-firmware}
2024 (@pxref{operating-system Reference, @code{firmware}}).
2026 @cindex RYF, Respects Your Freedom
2027 The @uref{https://www.fsf.org/, Free Software Foundation} runs
2028 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
2029 certification program for hardware products that respect your freedom
2030 and your privacy and ensure that you have control over your device. We
2031 encourage you to check the list of RYF-certified devices.
2033 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
2034 web site. It contains a catalog of hardware devices with information
2035 about their support in GNU/Linux.
2038 @node USB Stick and DVD Installation
2039 @section USB Stick and DVD Installation
2041 An ISO-9660 installation image that can be written to a USB stick or
2042 burnt to a DVD can be downloaded from
2043 @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso.xz},
2044 where you can replace @code{x86_64-linux} with one of:
2048 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
2051 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
2054 @c start duplication of authentication part from ``Binary Installation''
2055 Make sure to download the associated @file{.sig} file and to verify the
2056 authenticity of the image against it, along these lines:
2059 $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso.xz.sig
2060 $ gpg --verify guix-system-install-@value{VERSION}.x86_64-linux.iso.xz.sig
2063 If that command fails because you do not have the required public key,
2064 then run this command to import it:
2067 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
2068 -qO - | gpg --import -
2072 and rerun the @code{gpg --verify} command.
2074 Take note that a warning like ``This key is not certified with a trusted
2075 signature!'' is normal.
2079 This image contains the tools necessary for an installation.
2080 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
2082 @unnumberedsubsec Copying to a USB Stick
2084 To copy the image to a USB stick, follow these steps:
2088 Decompress the image using the @command{xz} command:
2091 xz -d guix-system-install-@value{VERSION}.x86_64-linux.iso.xz
2095 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
2096 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
2097 copy the image with:
2100 dd if=guix-system-install-@value{VERSION}.x86_64-linux.iso of=/dev/sdX status=progress
2104 Access to @file{/dev/sdX} usually requires root privileges.
2107 @unnumberedsubsec Burning on a DVD
2109 To copy the image to a DVD, follow these steps:
2113 Decompress the image using the @command{xz} command:
2116 xz -d guix-system-install-@value{VERSION}.x86_64-linux.iso.xz
2120 Insert a blank DVD into your machine, and determine
2121 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
2122 copy the image with:
2125 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.x86_64-linux.iso
2128 Access to @file{/dev/srX} usually requires root privileges.
2131 @unnumberedsubsec Booting
2133 Once this is done, you should be able to reboot the system and boot from
2134 the USB stick or DVD. The latter usually requires you to get in the
2135 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
2136 In order to boot from Libreboot, switch to the command mode by pressing
2137 the @kbd{c} key and type @command{search_grub usb}.
2139 @xref{Installing Guix in a VM}, if, instead, you would like to install
2140 Guix System in a virtual machine (VM).
2143 @node Preparing for Installation
2144 @section Preparing for Installation
2146 Once you have booted, you can use the guided graphical installer, which makes
2147 it easy to get started (@pxref{Guided Graphical Installation}). Alternatively,
2148 if you are already familiar with GNU/Linux and if you want more control than
2149 what the graphical installer provides, you can choose the ``manual''
2150 installation process (@pxref{Manual Installation}).
2152 The graphical installer is available on TTY1. You can obtain root shells on
2153 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
2154 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
2155 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
2156 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
2157 which allows you to select text with the left mouse button and to paste it
2158 with the middle button.
2161 Installation requires access to the Internet so that any missing
2162 dependencies of your system configuration can be downloaded. See the
2163 ``Networking'' section below.
2166 @node Guided Graphical Installation
2167 @section Guided Graphical Installation
2169 The graphical installer is a text-based user interface. It will guide you,
2170 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
2172 The first dialog boxes allow you to set up the system as you use it during the
2173 installation: you can choose the language, keyboard layout, and set up
2174 networking, which will be used during the installation. The image below shows
2175 the networking dialog.
2177 @image{images/installer-network,5in,, networking setup with the graphical installer}
2179 Later steps allow you to partition your hard disk, as shown in the image
2180 below, to choose whether or not to use encrypted file systems, to enter the
2181 host name and root password, and to create an additional account, among other
2184 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2186 Note that, at any time, the installer allows you to exit the current
2187 installation step and resume at a previous step, as show in the image below.
2189 @image{images/installer-resume,5in,, resuming the installation process}
2191 Once you're done, the installer produces an operating system configuration and
2192 displays it (@pxref{Using the Configuration System}). At that point you can
2193 hit ``OK'' and installation will proceed. On success, you can reboot into the
2194 new system and enjoy. @xref{After System Installation}, for what's next!
2197 @node Manual Installation
2198 @section Manual Installation
2200 This section describes how you would ``manually'' install GNU@tie{}Guix System
2201 on your machine. This option requires familiarity with GNU/Linux, with the
2202 shell, and with common administration tools. If you think this is not for
2203 you, consider using the guided graphical installer (@pxref{Guided Graphical
2206 The installation system provides root shells on TTYs 3 to 6; press
2207 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2208 many common tools needed to install the system. But it is also a full-blown
2209 Guix System, which means that you can install additional packages, should you
2210 need it, using @command{guix package} (@pxref{Invoking guix package}).
2213 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2214 * Proceeding with the Installation:: Installing.
2217 @node Keyboard Layout and Networking and Partitioning
2218 @subsection Keyboard Layout, Networking, and Partitioning
2220 Before you can install the system, you may want to adjust the keyboard layout,
2221 set up networking, and partition your target hard disk. This section will
2222 guide you through this.
2224 @subsubsection Keyboard Layout
2226 @cindex keyboard layout
2227 The installation image uses the US qwerty keyboard layout. If you want
2228 to change it, you can use the @command{loadkeys} command. For example,
2229 the following command selects the Dvorak keyboard layout:
2235 See the files under @file{/run/current-system/profile/share/keymaps} for
2236 a list of available keyboard layouts. Run @command{man loadkeys} for
2239 @subsubsection Networking
2241 Run the following command to see what your network interfaces are called:
2248 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2254 @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2255 Wired interfaces have a name starting with @samp{e}; for example, the
2256 interface corresponding to the first on-board Ethernet controller is
2257 called @samp{eno1}. Wireless interfaces have a name starting with
2258 @samp{w}, like @samp{w1p2s0}.
2261 @item Wired connection
2262 To configure a wired network run the following command, substituting
2263 @var{interface} with the name of the wired interface you want to use.
2266 ifconfig @var{interface} up
2270 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2273 ip link set @var{interface} up
2276 @item Wireless connection
2279 To configure wireless networking, you can create a configuration file
2280 for the @command{wpa_supplicant} configuration tool (its location is not
2281 important) using one of the available text editors such as
2285 nano wpa_supplicant.conf
2288 As an example, the following stanza can go to this file and will work
2289 for many wireless networks, provided you give the actual SSID and
2290 passphrase for the network you are connecting to:
2294 ssid="@var{my-ssid}"
2296 psk="the network's secret passphrase"
2300 Start the wireless service and run it in the background with the
2301 following command (substitute @var{interface} with the name of the
2302 network interface you want to use):
2305 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2308 Run @command{man wpa_supplicant} for more information.
2312 At this point, you need to acquire an IP address. On a network where IP
2313 addresses are automatically assigned @i{via} DHCP, you can run:
2316 dhclient -v @var{interface}
2319 Try to ping a server to see if networking is up and running:
2325 Setting up network access is almost always a requirement because the
2326 image does not contain all the software and tools that may be needed.
2328 @cindex proxy, during system installation
2329 If you need HTTP and HTTPS access to go through a proxy, run the
2333 herd set-http-proxy guix-daemon @var{URL}
2337 where @var{URL} is the proxy URL, for example
2338 @code{http://example.org:8118}.
2340 @cindex installing over SSH
2341 If you want to, you can continue the installation remotely by starting
2345 herd start ssh-daemon
2348 Make sure to either set a password with @command{passwd}, or configure
2349 OpenSSH public key authentication before logging in.
2351 @subsubsection Disk Partitioning
2353 Unless this has already been done, the next step is to partition, and
2354 then format the target partition(s).
2356 The installation image includes several partitioning tools, including
2357 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2358 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2359 the partition layout you want:
2365 If your disk uses the GUID Partition Table (GPT) format and you plan to
2366 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2367 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2370 @cindex EFI, installation
2371 @cindex UEFI, installation
2372 @cindex ESP, EFI system partition
2373 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2374 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2375 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2378 parted /dev/sda set 1 esp on
2382 @vindex grub-bootloader
2383 @vindex grub-efi-bootloader
2384 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2385 @file{/sys/firmware/efi} exists in the installation image, then you should
2386 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2387 Otherwise you should use the BIOS-based GRUB, known as
2388 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2392 Once you are done partitioning the target hard disk drive, you have to
2393 create a file system on the relevant partition(s)@footnote{Currently
2394 Guix System only supports ext4, btrfs, JFS, and F2FS file systems. In
2395 particular, code that reads file system UUIDs and labels only works for these
2396 file system types.}. For the ESP, if you have one and assuming it is
2397 @file{/dev/sda1}, run:
2400 mkfs.fat -F32 /dev/sda1
2403 For the root file system, ext4 is the most widely used format. Other
2404 file systems, such as Btrfs, support compression, which is reported to
2405 nicely complement file deduplication that the daemon performs
2406 independently of the file system (@pxref{Invoking guix-daemon,
2409 Preferably, assign file systems a label so that you can easily and
2410 reliably refer to them in @code{file-system} declarations (@pxref{File
2411 Systems}). This is typically done using the @code{-L} option of
2412 @command{mkfs.ext4} and related commands. So, assuming the target root
2413 partition lives at @file{/dev/sda2}, a file system with the label
2414 @code{my-root} can be created with:
2417 mkfs.ext4 -L my-root /dev/sda2
2420 @cindex encrypted disk
2421 If you are instead planning to encrypt the root partition, you can use
2422 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2423 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2424 @code{man cryptsetup}} for more information). Assuming you want to
2425 store the root partition on @file{/dev/sda2}, the command sequence would
2426 be along these lines:
2429 cryptsetup luksFormat /dev/sda2
2430 cryptsetup open --type luks /dev/sda2 my-partition
2431 mkfs.ext4 -L my-root /dev/mapper/my-partition
2434 Once that is done, mount the target file system under @file{/mnt}
2435 with a command like (again, assuming @code{my-root} is the label of the
2439 mount LABEL=my-root /mnt
2442 Also mount any other file systems you would like to use on the target
2443 system relative to this path. If you have opted for @file{/boot/efi} as an
2444 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2445 found by @code{guix system init} afterwards.
2447 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2448 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2449 sure to initialize them with @command{mkswap}. Assuming you have one
2450 swap partition on @file{/dev/sda3}, you would run:
2457 Alternatively, you may use a swap file. For example, assuming that in
2458 the new system you want to use the file @file{/swapfile} as a swap file,
2459 you would run@footnote{This example will work for many types of file
2460 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2461 btrfs), the required steps may be different. For details, see the
2462 manual pages for @command{mkswap} and @command{swapon}.}:
2465 # This is 10 GiB of swap space. Adjust "count" to change the size.
2466 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2467 # For security, make the file readable and writable only by root.
2468 chmod 600 /mnt/swapfile
2469 mkswap /mnt/swapfile
2470 swapon /mnt/swapfile
2473 Note that if you have encrypted the root partition and created a swap
2474 file in its file system as described above, then the encryption also
2475 protects the swap file, just like any other file in that file system.
2477 @node Proceeding with the Installation
2478 @subsection Proceeding with the Installation
2480 With the target partitions ready and the target root mounted on
2481 @file{/mnt}, we're ready to go. First, run:
2484 herd start cow-store /mnt
2487 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2488 during the installation phase are written to the target disk on @file{/mnt}
2489 rather than kept in memory. This is necessary because the first phase of
2490 the @command{guix system init} command (see below) entails downloads or
2491 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2493 Next, you have to edit a file and
2494 provide the declaration of the operating system to be installed. To
2495 that end, the installation system comes with three text editors. We
2496 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2497 supports syntax highlighting and parentheses matching; other editors
2498 include GNU Zile (an Emacs clone), and
2499 nvi (a clone of the original BSD @command{vi} editor).
2500 We strongly recommend storing that file on the target root file system, say,
2501 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2502 configuration file once you have rebooted into the newly-installed system.
2504 @xref{Using the Configuration System}, for an overview of the
2505 configuration file. The example configurations discussed in that
2506 section are available under @file{/etc/configuration} in the
2507 installation image. Thus, to get started with a system configuration
2508 providing a graphical display server (a ``desktop'' system), you can run
2509 something along these lines:
2513 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2514 # nano /mnt/etc/config.scm
2517 You should pay attention to what your configuration file contains, and
2522 Make sure the @code{bootloader-configuration} form refers to the target
2523 you want to install GRUB on. It should mention @code{grub-bootloader} if
2524 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2525 for newer UEFI systems. For legacy systems, the @code{target} field
2526 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2527 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2528 currently mounted and a @code{file-system} entry is specified in your
2532 Be sure that your file system labels match the value of their respective
2533 @code{device} fields in your @code{file-system} configuration, assuming
2534 your @code{file-system} configuration uses the @code{file-system-label}
2535 procedure in its @code{device} field.
2538 If there are encrypted or RAID partitions, make sure to add a
2539 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2542 Once you are done preparing the configuration file, the new system must
2543 be initialized (remember that the target root file system is mounted
2547 guix system init /mnt/etc/config.scm /mnt
2551 This copies all the necessary files and installs GRUB on
2552 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2553 more information, @pxref{Invoking guix system}. This command may trigger
2554 downloads or builds of missing packages, which can take some time.
2556 Once that command has completed---and hopefully succeeded!---you can run
2557 @command{reboot} and boot into the new system. The @code{root} password
2558 in the new system is initially empty; other users' passwords need to be
2559 initialized by running the @command{passwd} command as @code{root},
2560 unless your configuration specifies otherwise
2561 (@pxref{user-account-password, user account passwords}).
2562 @xref{After System Installation}, for what's next!
2565 @node After System Installation
2566 @section After System Installation
2568 Success, you've now booted into Guix System! From then on, you can update the
2569 system whenever you want by running, say:
2573 sudo guix system reconfigure /etc/config.scm
2577 This builds a new system generation with the latest packages and services
2578 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2579 your system includes the latest security updates (@pxref{Security Updates}).
2581 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2583 @cindex sudo vs. @command{guix pull}
2584 Note that @command{sudo guix} runs your user's @command{guix} command and
2585 @emph{not} root's, because @command{sudo} leaves @env{PATH} unchanged. To
2586 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2588 The difference matters here, because @command{guix pull} updates
2589 the @command{guix} command and package definitions only for the user it is ran
2590 as. This means that if you choose to use @command{guix system reconfigure} in
2591 root's login shell, you'll need to @command{guix pull} separately.
2594 Now, @pxref{Getting Started}, and
2595 join us on @code{#guix} on the Freenode IRC network or on
2596 @email{guix-devel@@gnu.org} to share your experience!
2599 @node Installing Guix in a VM
2600 @section Installing Guix in a Virtual Machine
2602 @cindex virtual machine, Guix System installation
2603 @cindex virtual private server (VPS)
2604 @cindex VPS (virtual private server)
2605 If you'd like to install Guix System in a virtual machine (VM) or on a
2606 virtual private server (VPS) rather than on your beloved machine, this
2609 To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
2610 disk image, follow these steps:
2614 First, retrieve and decompress the Guix system installation image as
2615 described previously (@pxref{USB Stick and DVD Installation}).
2618 Create a disk image that will hold the installed system. To make a
2619 qcow2-formatted disk image, use the @command{qemu-img} command:
2622 qemu-img create -f qcow2 guix-system.img 50G
2625 The resulting file will be much smaller than 50 GB (typically less than
2626 1 MB), but it will grow as the virtualized storage device is filled up.
2629 Boot the USB installation image in an VM:
2632 qemu-system-x86_64 -m 1024 -smp 1 -enable-kvm \
2633 -nic user,model=virtio-net-pci -boot menu=on,order=d \
2634 -drive file=guix-system.img \
2635 -drive media=cdrom,file=guix-system-install-@value{VERSION}.@var{system}.iso
2638 @code{-enable-kvm} is optional, but significantly improves performance,
2639 @pxref{Running Guix in a VM}.
2642 You're now root in the VM, proceed with the installation process.
2643 @xref{Preparing for Installation}, and follow the instructions.
2646 Once installation is complete, you can boot the system that's on your
2647 @file{guix-system.img} image. @xref{Running Guix in a VM}, for how to do
2650 @node Building the Installation Image
2651 @section Building the Installation Image
2653 @cindex installation image
2654 The installation image described above was built using the @command{guix
2655 system} command, specifically:
2658 guix system disk-image -t iso9660 gnu/system/install.scm
2661 Have a look at @file{gnu/system/install.scm} in the source tree,
2662 and see also @ref{Invoking guix system} for more information
2663 about the installation image.
2665 @section Building the Installation Image for ARM Boards
2667 Many ARM boards require a specific variant of the
2668 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2670 If you build a disk image and the bootloader is not available otherwise
2671 (on another boot drive etc), it's advisable to build an image that
2672 includes the bootloader, specifically:
2675 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2678 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2679 board, a list of possible boards will be printed.
2681 @c *********************************************************************
2682 @node Getting Started
2683 @chapter Getting Started
2685 Presumably, you've reached this section because either you have
2686 installed Guix on top of another distribution (@pxref{Installation}), or
2687 you've installed the standalone Guix System (@pxref{System
2688 Installation}). It's time for you to get started using Guix and this
2689 section aims to help you do that and give you a feel of what it's like.
2691 Guix is about installing software, so probably the first thing you'll
2692 want to do is to actually look for software. Let's say you're looking
2693 for a text editor, you can run:
2696 guix search text editor
2699 This command shows you a number of matching @dfn{packages}, each time
2700 showing the package's name, version, a description, and additional info.
2701 Once you've found out the one you want to use, let's say Emacs (ah ha!),
2702 you can go ahead and install it (run this command as a regular user,
2703 @emph{no need for root privileges}!):
2709 You've installed your first package, congrats! In the process, you've
2710 probably noticed that Guix downloaded pre-built binaries; or, if you
2711 explicitly chose to @emph{not} use pre-built binaries, then probably
2712 Guix is still building software (@pxref{Substitutes}, for more info).
2714 Unless you're using Guix System, the @command{guix install} command must
2715 have printed this hint:
2718 hint: Consider setting the necessary environment variables by running:
2720 GUIX_PROFILE="$HOME/.guix-profile"
2721 . "$GUIX_PROFILE/etc/profile"
2723 Alternately, see `guix package --search-paths -p "$HOME/.guix-profile"'.
2726 Indeed, you must now tell your shell where @command{emacs} and other
2727 programs installed with Guix are to be found. Pasting the two lines
2728 above will do just that: it will add
2729 @code{$HOME/.guix-profile/bin}---which is where the installed package
2730 is---to the @code{PATH} environment variable. You can paste these two
2731 lines in your shell so they take effect right away, but more importantly
2732 you should add them to @file{~/.bash_profile} (or equivalent file if you
2733 do not use Bash) so that environment variables are set next time you
2734 spawn a shell. You only need to do this once and other search paths
2735 environment variables will be taken care of similarly---e.g., if you
2736 eventually install @code{python} and Python libraries, @code{PYTHONPATH}
2739 You can go on installing packages at your will. To list installed
2743 guix package --list-installed
2746 To remove a package, you would unsurprisingly run @command{guix remove}.
2747 A distinguishing feature is the ability to @dfn{roll back} any operation
2748 you made---installation, removal, upgrade---by simply typing:
2751 guix package --roll-back
2754 This is because each operation is in fact a @dfn{transaction} that
2755 creates a new @dfn{generation}. These generations and the difference
2756 between them can be displayed by running:
2759 guix package --list-generations
2762 Now you know the basics of package management!
2764 @quotation Going further
2765 @xref{Package Management}, for more about package management. You may
2766 like @dfn{declarative} package management with @command{guix package
2767 --manifest}, managing separate @dfn{profiles} with @option{--profile},
2768 deleting old generations, collecting garbage, and other nifty features
2769 that will come in handy as you become more familiar with Guix. If you
2770 are a developer, @pxref{Development} for additional tools. And if
2771 you're curious, @pxref{Features}, to peek under the hood.
2774 Once you've installed a set of packages, you will want to periodically
2775 @emph{upgrade} them to the latest and greatest version. To do that, you
2776 will first pull the latest revision of Guix and its package collection:
2782 The end result is a new @command{guix} command, under
2783 @file{~/.config/guix/current/bin}. Unless you're on Guix System, the
2784 first time you run @command{guix pull}, be sure to follow the hint that
2785 the command prints and, similar to what we saw above, paste these two
2786 lines in your terminal and @file{.bash_profile}:
2789 GUIX_PROFILE="$HOME/.config/guix/current"
2790 . "$GUIX_PROFILE/etc/profile"
2794 You must also instruct your shell to point to this new @command{guix}:
2800 At this point, you're running a brand new Guix. You can thus go ahead
2801 and actually upgrade all the packages you previously installed:
2807 As you run this command, you will see that binaries are downloaded (or
2808 perhaps some packages are built), and eventually you end up with the
2809 upgraded packages. Should one of these upgraded packages not be to your
2810 liking, remember you can always roll back!
2812 You can display the exact revision of Guix you're currently using by
2819 The information it displays is @emph{all it takes to reproduce the exact
2820 same Guix}, be it at a different point in time or on a different
2823 @quotation Going further
2824 @xref{Invoking guix pull}, for more information. @xref{Channels}, on
2825 how to specify additional @dfn{channels} to pull packages from, how to
2826 replicate Guix, and more. You may also find @command{time-machine}
2827 handy (@pxref{Invoking guix time-machine}).
2830 If you installed Guix System, one of the first things you'll want to do
2831 is to upgrade your system. Once you've run @command{guix pull} to get
2832 the latest Guix, you can upgrade the system like this:
2835 sudo guix system reconfigure /etc/config.scm
2838 Upon completion, the system runs the latest versions of its software
2839 packages. When you eventually reboot, you'll notice a sub-menu in the
2840 bootloader that reads ``Old system generations'': it's what allows you
2841 to boot @emph{an older generation of your system}, should the latest
2842 generation be ``broken'' or otherwise unsatisfying. Just like for
2843 packages, you can always @emph{roll back} to a previous generation
2844 @emph{of the whole system}:
2847 sudo guix system roll-back
2850 There are many things you'll probably want to tweak on your system:
2851 adding new user accounts, adding new system services, fiddling with the
2852 configuration of those services, etc. The system configuration is
2853 @emph{entirely} described in the @file{/etc/config.scm} file.
2854 @xref{Using the Configuration System}, to learn how to change it.
2856 Now you know enough to get started!
2858 @quotation Resources
2859 The rest of this manual provides a reference for all things Guix. Here
2860 are some additional resources you may find useful:
2864 @xref{Top,,, guix-cookbook, The GNU Guix Cookbook}, for a list of
2865 ``how-to'' style of recipes for a variety of applications.
2868 The @uref{https://guix.gnu.org/guix-refcard.pdf, GNU Guix Reference
2869 Card} lists in two pages most of the commands and options you'll ever
2873 The web site contains @uref{https://guix.gnu.org/en/videos/,
2874 instructional videos} covering topics such as everyday use of Guix, how
2875 to get help, and how to become a contributor.
2878 @xref{Documentation}, to learn how to access documentation on your
2882 We hope you will enjoy Guix as much as the community enjoys building it!
2885 @c *********************************************************************
2886 @node Package Management
2887 @chapter Package Management
2890 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2891 remove software packages, without having to know about their build
2892 procedures or dependencies. Guix also goes beyond this obvious set of
2895 This chapter describes the main features of Guix, as well as the
2896 package management tools it provides. Along with the command-line
2897 interface described below (@pxref{Invoking guix package, @code{guix
2898 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2899 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2900 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2904 guix install emacs-guix
2908 * Features:: How Guix will make your life brighter.
2909 * Invoking guix package:: Package installation, removal, etc.
2910 * Substitutes:: Downloading pre-built binaries.
2911 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2912 * Invoking guix gc:: Running the garbage collector.
2913 * Invoking guix pull:: Fetching the latest Guix and distribution.
2914 * Invoking guix time-machine:: Running an older revision of Guix.
2915 * Inferiors:: Interacting with another revision of Guix.
2916 * Invoking guix describe:: Display information about your Guix revision.
2917 * Invoking guix archive:: Exporting and importing store files.
2923 Here we assume you've already made your first steps with Guix
2924 (@pxref{Getting Started}) and would like to get an overview about what's
2925 going on under the hood.
2927 When using Guix, each package ends up in the @dfn{package store}, in its
2928 own directory---something that resembles
2929 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2931 Instead of referring to these directories, users have their own
2932 @dfn{profile}, which points to the packages that they actually want to
2933 use. These profiles are stored within each user's home directory, at
2934 @code{$HOME/.guix-profile}.
2936 For example, @code{alice} installs GCC 4.7.2. As a result,
2937 @file{/home/alice/.guix-profile/bin/gcc} points to
2938 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
2939 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
2940 simply continues to point to
2941 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
2942 coexist on the same system without any interference.
2944 The @command{guix package} command is the central tool to manage
2945 packages (@pxref{Invoking guix package}). It operates on the per-user
2946 profiles, and can be used @emph{with normal user privileges}.
2948 @cindex transactions
2949 The command provides the obvious install, remove, and upgrade
2950 operations. Each invocation is actually a @emph{transaction}: either
2951 the specified operation succeeds, or nothing happens. Thus, if the
2952 @command{guix package} process is terminated during the transaction,
2953 or if a power outage occurs during the transaction, then the user's
2954 profile remains in its previous state, and remains usable.
2956 In addition, any package transaction may be @emph{rolled back}. So, if,
2957 for example, an upgrade installs a new version of a package that turns
2958 out to have a serious bug, users may roll back to the previous instance
2959 of their profile, which was known to work well. Similarly, the global
2960 system configuration on Guix is subject to
2961 transactional upgrades and roll-back
2962 (@pxref{Using the Configuration System}).
2964 All packages in the package store may be @emph{garbage-collected}.
2965 Guix can determine which packages are still referenced by user
2966 profiles, and remove those that are provably no longer referenced
2967 (@pxref{Invoking guix gc}). Users may also explicitly remove old
2968 generations of their profile so that the packages they refer to can be
2971 @cindex reproducibility
2972 @cindex reproducible builds
2973 Guix takes a @dfn{purely functional} approach to package
2974 management, as described in the introduction (@pxref{Introduction}).
2975 Each @file{/gnu/store} package directory name contains a hash of all the
2976 inputs that were used to build that package---compiler, libraries, build
2977 scripts, etc. This direct correspondence allows users to make sure a
2978 given package installation matches the current state of their
2979 distribution. It also helps maximize @dfn{build reproducibility}:
2980 thanks to the isolated build environments that are used, a given build
2981 is likely to yield bit-identical files when performed on different
2982 machines (@pxref{Invoking guix-daemon, container}).
2985 This foundation allows Guix to support @dfn{transparent binary/source
2986 deployment}. When a pre-built binary for a @file{/gnu/store} item is
2987 available from an external source---a @dfn{substitute}, Guix just
2988 downloads it and unpacks it;
2989 otherwise, it builds the package from source, locally
2990 (@pxref{Substitutes}). Because build results are usually bit-for-bit
2991 reproducible, users do not have to trust servers that provide
2992 substitutes: they can force a local build and @emph{challenge} providers
2993 (@pxref{Invoking guix challenge}).
2995 Control over the build environment is a feature that is also useful for
2996 developers. The @command{guix environment} command allows developers of
2997 a package to quickly set up the right development environment for their
2998 package, without having to manually install the dependencies of the
2999 package into their profile (@pxref{Invoking guix environment}).
3001 @cindex replication, of software environments
3002 @cindex provenance tracking, of software artifacts
3003 All of Guix and its package definitions is version-controlled, and
3004 @command{guix pull} allows you to ``travel in time'' on the history of Guix
3005 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
3006 Guix instance on a different machine or at a later point in time, which in
3007 turn allows you to @emph{replicate complete software environments}, while
3008 retaining precise @dfn{provenance tracking} of the software.
3010 @node Invoking guix package
3011 @section Invoking @command{guix package}
3013 @cindex installing packages
3014 @cindex removing packages
3015 @cindex package installation
3016 @cindex package removal
3017 The @command{guix package} command is the tool that allows users to
3018 install, upgrade, and remove packages, as well as rolling back to
3019 previous configurations. It operates only on the user's own profile,
3020 and works with normal user privileges (@pxref{Features}). Its syntax
3024 guix package @var{options}
3027 @cindex transactions
3028 Primarily, @var{options} specifies the operations to be performed during
3029 the transaction. Upon completion, a new profile is created, but
3030 previous @dfn{generations} of the profile remain available, should the user
3033 For example, to remove @code{lua} and install @code{guile} and
3034 @code{guile-cairo} in a single transaction:
3037 guix package -r lua -i guile guile-cairo
3040 @cindex aliases, for @command{guix package}
3041 For your convenience, we also provide the following aliases:
3045 @command{guix search} is an alias for @command{guix package -s},
3047 @command{guix install} is an alias for @command{guix package -i},
3049 @command{guix remove} is an alias for @command{guix package -r},
3051 @command{guix upgrade} is an alias for @command{guix package -u},
3053 and @command{guix show} is an alias for @command{guix package --show=}.
3056 These aliases are less expressive than @command{guix package} and provide
3057 fewer options, so in some cases you'll probably want to use @command{guix
3060 @command{guix package} also supports a @dfn{declarative approach}
3061 whereby the user specifies the exact set of packages to be available and
3062 passes it @i{via} the @option{--manifest} option
3063 (@pxref{profile-manifest, @option{--manifest}}).
3066 For each user, a symlink to the user's default profile is automatically
3067 created in @file{$HOME/.guix-profile}. This symlink always points to the
3068 current generation of the user's default profile. Thus, users can add
3069 @file{$HOME/.guix-profile/bin} to their @env{PATH} environment
3070 variable, and so on.
3071 @cindex search paths
3072 If you are not using Guix System, consider adding the
3073 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
3074 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
3075 shells get all the right environment variable definitions:
3078 GUIX_PROFILE="$HOME/.guix-profile" ; \
3079 source "$HOME/.guix-profile/etc/profile"
3082 In a multi-user setup, user profiles are stored in a place registered as
3083 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
3084 to (@pxref{Invoking guix gc}). That directory is normally
3085 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
3086 @var{localstatedir} is the value passed to @code{configure} as
3087 @option{--localstatedir}, and @var{user} is the user name. The
3088 @file{per-user} directory is created when @command{guix-daemon} is
3089 started, and the @var{user} sub-directory is created by @command{guix
3092 The @var{options} can be among the following:
3096 @item --install=@var{package} @dots{}
3097 @itemx -i @var{package} @dots{}
3098 Install the specified @var{package}s.
3100 Each @var{package} may specify either a simple package name, such as
3101 @code{guile}, or a package name followed by an at-sign and version number,
3102 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
3103 case, the newest version prefixed by @code{1.8} is selected).
3105 If no version number is specified, the
3106 newest available version will be selected. In addition, @var{package}
3107 may contain a colon, followed by the name of one of the outputs of the
3108 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
3109 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
3110 name (and optionally version) are searched for among the GNU
3111 distribution modules (@pxref{Package Modules}).
3113 @cindex propagated inputs
3114 Sometimes packages have @dfn{propagated inputs}: these are dependencies
3115 that automatically get installed along with the required package
3116 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
3117 @code{package} objects}, for information about propagated inputs in
3118 package definitions).
3120 @anchor{package-cmd-propagated-inputs}
3121 An example is the GNU MPC library: its C header files refer to those of
3122 the GNU MPFR library, which in turn refer to those of the GMP library.
3123 Thus, when installing MPC, the MPFR and GMP libraries also get installed
3124 in the profile; removing MPC also removes MPFR and GMP---unless they had
3125 also been explicitly installed by the user.
3127 Besides, packages sometimes rely on the definition of environment
3128 variables for their search paths (see explanation of
3129 @option{--search-paths} below). Any missing or possibly incorrect
3130 environment variable definitions are reported here.
3132 @item --install-from-expression=@var{exp}
3134 Install the package @var{exp} evaluates to.
3136 @var{exp} must be a Scheme expression that evaluates to a
3137 @code{<package>} object. This option is notably useful to disambiguate
3138 between same-named variants of a package, with expressions such as
3139 @code{(@@ (gnu packages base) guile-final)}.
3141 Note that this option installs the first output of the specified
3142 package, which may be insufficient when needing a specific output of a
3143 multiple-output package.
3145 @item --install-from-file=@var{file}
3146 @itemx -f @var{file}
3147 Install the package that the code within @var{file} evaluates to.
3149 As an example, @var{file} might contain a definition like this
3150 (@pxref{Defining Packages}):
3153 @include package-hello.scm
3156 Developers may find it useful to include such a @file{guix.scm} file
3157 in the root of their project source tree that can be used to test
3158 development snapshots and create reproducible development environments
3159 (@pxref{Invoking guix environment}).
3161 The @var{file} may also contain a JSON representation of one or more
3162 package definitions. Running @code{guix package -f} on
3163 @file{hello.json} with the following contents would result in installing
3164 the package @code{greeter} after building @code{myhello}:
3167 @verbatiminclude package-hello.json
3170 @item --remove=@var{package} @dots{}
3171 @itemx -r @var{package} @dots{}
3172 Remove the specified @var{package}s.
3174 As for @option{--install}, each @var{package} may specify a version number
3175 and/or output name in addition to the package name. For instance,
3176 @samp{-r glibc:debug} would remove the @code{debug} output of
3179 @item --upgrade[=@var{regexp} @dots{}]
3180 @itemx -u [@var{regexp} @dots{}]
3181 @cindex upgrading packages
3182 Upgrade all the installed packages. If one or more @var{regexp}s are
3183 specified, upgrade only installed packages whose name matches a
3184 @var{regexp}. Also see the @option{--do-not-upgrade} option below.
3186 Note that this upgrades package to the latest version of packages found
3187 in the distribution currently installed. To update your distribution,
3188 you should regularly run @command{guix pull} (@pxref{Invoking guix
3191 @cindex package transformations, upgrades
3192 When upgrading, package transformations that were originally applied
3193 when creating the profile are automatically re-applied (@pxref{Package
3194 Transformation Options}). For example, assume you first installed Emacs
3195 from the tip of its development branch with:
3198 guix install emacs-next --with-branch=emacs-next=master
3201 Next time you run @command{guix upgrade}, Guix will again pull the tip
3202 of the Emacs development branch and build @code{emacs-next} from that
3205 Note that transformation options such as @option{--with-branch} and
3206 @option{--with-source} depend on external state; it is up to you to
3207 ensure that they work as expected. You can also discard a
3208 transformations that apply to a package by running:
3211 guix install @var{package}
3214 @item --do-not-upgrade[=@var{regexp} @dots{}]
3215 When used together with the @option{--upgrade} option, do @emph{not}
3216 upgrade any packages whose name matches a @var{regexp}. For example, to
3217 upgrade all packages in the current profile except those containing the
3218 substring ``emacs'':
3221 $ guix package --upgrade . --do-not-upgrade emacs
3224 @item @anchor{profile-manifest}--manifest=@var{file}
3225 @itemx -m @var{file}
3226 @cindex profile declaration
3227 @cindex profile manifest
3228 Create a new generation of the profile from the manifest object
3229 returned by the Scheme code in @var{file}. This option can be repeated
3230 several times, in which case the manifests are concatenated.
3232 This allows you to @emph{declare} the profile's contents rather than
3233 constructing it through a sequence of @option{--install} and similar
3234 commands. The advantage is that @var{file} can be put under version
3235 control, copied to different machines to reproduce the same profile, and
3238 @c FIXME: Add reference to (guix profile) documentation when available.
3239 @var{file} must return a @dfn{manifest} object, which is roughly a list
3242 @findex packages->manifest
3244 (use-package-modules guile emacs)
3249 ;; Use a specific package output.
3250 (list guile-2.0 "debug")))
3253 @findex specifications->manifest
3254 In this example we have to know which modules define the @code{emacs}
3255 and @code{guile-2.0} variables to provide the right
3256 @code{use-package-modules} line, which can be cumbersome. We can
3257 instead provide regular package specifications and let
3258 @code{specifications->manifest} look up the corresponding package
3262 (specifications->manifest
3263 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
3267 @cindex rolling back
3268 @cindex undoing transactions
3269 @cindex transactions, undoing
3270 Roll back to the previous @dfn{generation} of the profile---i.e., undo
3271 the last transaction.
3273 When combined with options such as @option{--install}, roll back occurs
3274 before any other actions.
3276 When rolling back from the first generation that actually contains
3277 installed packages, the profile is made to point to the @dfn{zeroth
3278 generation}, which contains no files apart from its own metadata.
3280 After having rolled back, installing, removing, or upgrading packages
3281 overwrites previous future generations. Thus, the history of the
3282 generations in a profile is always linear.
3284 @item --switch-generation=@var{pattern}
3285 @itemx -S @var{pattern}
3287 Switch to a particular generation defined by @var{pattern}.
3289 @var{pattern} may be either a generation number or a number prefixed
3290 with ``+'' or ``-''. The latter means: move forward/backward by a
3291 specified number of generations. For example, if you want to return to
3292 the latest generation after @option{--roll-back}, use
3293 @option{--switch-generation=+1}.
3295 The difference between @option{--roll-back} and
3296 @option{--switch-generation=-1} is that @option{--switch-generation} will
3297 not make a zeroth generation, so if a specified generation does not
3298 exist, the current generation will not be changed.
3300 @item --search-paths[=@var{kind}]
3301 @cindex search paths
3302 Report environment variable definitions, in Bash syntax, that may be
3303 needed in order to use the set of installed packages. These environment
3304 variables are used to specify @dfn{search paths} for files used by some
3305 of the installed packages.
3307 For example, GCC needs the @env{CPATH} and @env{LIBRARY_PATH}
3308 environment variables to be defined so it can look for headers and
3309 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
3310 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
3311 library are installed in the profile, then @option{--search-paths} will
3312 suggest setting these variables to @file{@var{profile}/include} and
3313 @file{@var{profile}/lib}, respectively.
3315 The typical use case is to define these environment variables in the
3319 $ eval `guix package --search-paths`
3322 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
3323 meaning that the returned environment variable definitions will either
3324 be exact settings, or prefixes or suffixes of the current value of these
3325 variables. When omitted, @var{kind} defaults to @code{exact}.
3327 This option can also be used to compute the @emph{combined} search paths
3328 of several profiles. Consider this example:
3331 $ guix package -p foo -i guile
3332 $ guix package -p bar -i guile-json
3333 $ guix package -p foo -p bar --search-paths
3336 The last command above reports about the @env{GUILE_LOAD_PATH}
3337 variable, even though, taken individually, neither @file{foo} nor
3338 @file{bar} would lead to that recommendation.
3341 @item --profile=@var{profile}
3342 @itemx -p @var{profile}
3343 Use @var{profile} instead of the user's default profile.
3345 @var{profile} must be the name of a file that will be created upon
3346 completion. Concretely, @var{profile} will be a mere symbolic link
3347 (``symlink'') pointing to the actual profile where packages are
3351 $ guix install hello -p ~/code/my-profile
3353 $ ~/code/my-profile/bin/hello
3357 All it takes to get rid of the profile is to remove this symlink and its
3358 siblings that point to specific generations:
3361 $ rm ~/code/my-profile ~/code/my-profile-*-link
3364 @item --list-profiles
3365 List all the user's profiles:
3368 $ guix package --list-profiles
3369 /home/charlie/.guix-profile
3370 /home/charlie/code/my-profile
3371 /home/charlie/code/devel-profile
3372 /home/charlie/tmp/test
3375 When running as root, list all the profiles of all the users.
3377 @cindex collisions, in a profile
3378 @cindex colliding packages in profiles
3379 @cindex profile collisions
3380 @item --allow-collisions
3381 Allow colliding packages in the new profile. Use at your own risk!
3383 By default, @command{guix package} reports as an error @dfn{collisions}
3384 in the profile. Collisions happen when two or more different versions
3385 or variants of a given package end up in the profile.
3388 Use the bootstrap Guile to build the profile. This option is only
3389 useful to distribution developers.
3393 In addition to these actions, @command{guix package} supports the
3394 following options to query the current state of a profile, or the
3395 availability of packages:
3399 @item --search=@var{regexp}
3400 @itemx -s @var{regexp}
3401 @anchor{guix-search}
3402 @cindex searching for packages
3403 List the available packages whose name, synopsis, or description matches
3404 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
3405 Print all the metadata of matching packages in
3406 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
3407 GNU recutils manual}).
3409 This allows specific fields to be extracted using the @command{recsel}
3410 command, for instance:
3413 $ guix package -s malloc | recsel -p name,version,relevance
3427 Similarly, to show the name of all the packages available under the
3428 terms of the GNU@tie{}LGPL version 3:
3431 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
3438 It is also possible to refine search results using several @code{-s} flags to
3439 @command{guix package}, or several arguments to @command{guix search}. For
3440 example, the following command returns a list of board games (this time using
3441 the @command{guix search} alias):
3444 $ guix search '\<board\>' game | recsel -p name
3449 If we were to omit @code{-s game}, we would also get software packages
3450 that deal with printed circuit boards; removing the angle brackets
3451 around @code{board} would further add packages that have to do with
3454 And now for a more elaborate example. The following command searches
3455 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
3456 libraries, and prints the name and synopsis of the matching packages:
3459 $ guix search crypto library | \
3460 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
3464 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
3465 information on @dfn{selection expressions} for @code{recsel -e}.
3467 @item --show=@var{package}
3468 Show details about @var{package}, taken from the list of available packages, in
3469 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
3473 $ guix package --show=python | recsel -p name,version
3481 You may also specify the full name of a package to only get details about a
3482 specific version of it (this time using the @command{guix show} alias):
3484 $ guix show python@@3.4 | recsel -p name,version
3491 @item --list-installed[=@var{regexp}]
3492 @itemx -I [@var{regexp}]
3493 List the currently installed packages in the specified profile, with the
3494 most recently installed packages shown last. When @var{regexp} is
3495 specified, list only installed packages whose name matches @var{regexp}.
3497 For each installed package, print the following items, separated by
3498 tabs: the package name, its version string, the part of the package that
3499 is installed (for instance, @code{out} for the default output,
3500 @code{include} for its headers, etc.), and the path of this package in
3503 @item --list-available[=@var{regexp}]
3504 @itemx -A [@var{regexp}]
3505 List packages currently available in the distribution for this system
3506 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3507 available packages whose name matches @var{regexp}.
3509 For each package, print the following items separated by tabs: its name,
3510 its version string, the parts of the package (@pxref{Packages with
3511 Multiple Outputs}), and the source location of its definition.
3513 @item --list-generations[=@var{pattern}]
3514 @itemx -l [@var{pattern}]
3516 Return a list of generations along with their creation dates; for each
3517 generation, show the installed packages, with the most recently
3518 installed packages shown last. Note that the zeroth generation is never
3521 For each installed package, print the following items, separated by
3522 tabs: the name of a package, its version string, the part of the package
3523 that is installed (@pxref{Packages with Multiple Outputs}), and the
3524 location of this package in the store.
3526 When @var{pattern} is used, the command returns only matching
3527 generations. Valid patterns include:
3530 @item @emph{Integers and comma-separated integers}. Both patterns denote
3531 generation numbers. For instance, @option{--list-generations=1} returns
3534 And @option{--list-generations=1,8,2} outputs three generations in the
3535 specified order. Neither spaces nor trailing commas are allowed.
3537 @item @emph{Ranges}. @option{--list-generations=2..9} prints the
3538 specified generations and everything in between. Note that the start of
3539 a range must be smaller than its end.
3541 It is also possible to omit the endpoint. For example,
3542 @option{--list-generations=2..}, returns all generations starting from the
3545 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3546 or months by passing an integer along with the first letter of the
3547 duration. For example, @option{--list-generations=20d} lists generations
3548 that are up to 20 days old.
3551 @item --delete-generations[=@var{pattern}]
3552 @itemx -d [@var{pattern}]
3553 When @var{pattern} is omitted, delete all generations except the current
3556 This command accepts the same patterns as @option{--list-generations}.
3557 When @var{pattern} is specified, delete the matching generations. When
3558 @var{pattern} specifies a duration, generations @emph{older} than the
3559 specified duration match. For instance, @option{--delete-generations=1m}
3560 deletes generations that are more than one month old.
3562 If the current generation matches, it is @emph{not} deleted. Also, the
3563 zeroth generation is never deleted.
3565 Note that deleting generations prevents rolling back to them.
3566 Consequently, this command must be used with care.
3570 Finally, since @command{guix package} may actually start build
3571 processes, it supports all the common build options (@pxref{Common Build
3572 Options}). It also supports package transformation options, such as
3573 @option{--with-source} (@pxref{Package Transformation Options}).
3574 However, note that package transformations are lost when upgrading; to
3575 preserve transformations across upgrades, you should define your own
3576 package variant in a Guile module and add it to @env{GUIX_PACKAGE_PATH}
3577 (@pxref{Defining Packages}).
3580 @section Substitutes
3583 @cindex pre-built binaries
3584 Guix supports transparent source/binary deployment, which means that it
3585 can either build things locally, or download pre-built items from a
3586 server, or both. We call these pre-built items @dfn{substitutes}---they
3587 are substitutes for local build results. In many cases, downloading a
3588 substitute is much faster than building things locally.
3590 Substitutes can be anything resulting from a derivation build
3591 (@pxref{Derivations}). Of course, in the common case, they are
3592 pre-built package binaries, but source tarballs, for instance, which
3593 also result from derivation builds, can be available as substitutes.
3596 * Official Substitute Server:: One particular source of substitutes.
3597 * Substitute Server Authorization:: How to enable or disable substitutes.
3598 * Getting Substitutes from Other Servers:: Substitute diversity.
3599 * Substitute Authentication:: How Guix verifies substitutes.
3600 * Proxy Settings:: How to get substitutes via proxy.
3601 * Substitution Failure:: What happens when substitution fails.
3602 * On Trusting Binaries:: How can you trust that binary blob?
3605 @node Official Substitute Server
3606 @subsection Official Substitute Server
3609 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
3610 that builds packages from Guix continuously for some
3611 architectures, and makes them available as substitutes. This is the
3612 default source of substitutes; it can be overridden by passing the
3613 @option{--substitute-urls} option either to @command{guix-daemon}
3614 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3615 or to client tools such as @command{guix package}
3616 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3619 Substitute URLs can be either HTTP or HTTPS.
3620 HTTPS is recommended because communications are encrypted; conversely,
3621 using HTTP makes all communications visible to an eavesdropper, who
3622 could use the information gathered to determine, for instance, whether
3623 your system has unpatched security vulnerabilities.
3625 Substitutes from the official build farm are enabled by default when
3626 using Guix System (@pxref{GNU Distribution}). However,
3627 they are disabled by default when using Guix on a foreign distribution,
3628 unless you have explicitly enabled them via one of the recommended
3629 installation steps (@pxref{Installation}). The following paragraphs
3630 describe how to enable or disable substitutes for the official build
3631 farm; the same procedure can also be used to enable substitutes for any
3632 other substitute server.
3634 @node Substitute Server Authorization
3635 @subsection Substitute Server Authorization
3638 @cindex substitutes, authorization thereof
3639 @cindex access control list (ACL), for substitutes
3640 @cindex ACL (access control list), for substitutes
3641 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
3643 must add its public key to the access control list (ACL) of archive
3644 imports, using the @command{guix archive} command (@pxref{Invoking guix
3645 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
3646 be compromised and to serve genuine substitutes.
3649 If you are using Guix System, you can skip this section: Guix System
3650 authorizes substitutes from @code{@value{SUBSTITUTE-SERVER}} by default.
3653 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
3654 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
3655 the installation prefix of Guix. If you installed Guix from source,
3656 make sure you checked the GPG signature of
3657 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3658 Then, you can run something like this:
3661 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
3664 Once this is in place, the output of a command like @code{guix build}
3665 should change from something like:
3668 $ guix build emacs --dry-run
3669 The following derivations would be built:
3670 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3671 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3672 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3673 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3681 $ guix build emacs --dry-run
3682 112.3 MB would be downloaded:
3683 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3684 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3685 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3686 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3691 The text changed from ``The following derivations would be built'' to
3692 ``112.3 MB would be downloaded''. This indicates that substitutes from
3693 @code{@value{SUBSTITUTE-SERVER}} are usable and will be downloaded, when
3694 possible, for future builds.
3696 @cindex substitutes, how to disable
3697 The substitute mechanism can be disabled globally by running
3698 @code{guix-daemon} with @option{--no-substitutes} (@pxref{Invoking
3699 guix-daemon}). It can also be disabled temporarily by passing the
3700 @option{--no-substitutes} option to @command{guix package},
3701 @command{guix build}, and other command-line tools.
3703 @node Getting Substitutes from Other Servers
3704 @subsection Getting Substitutes from Other Servers
3706 @cindex substitute servers, adding more
3707 Guix can look up and fetch substitutes from several servers. This is
3708 useful when you are using packages from additional channels for which
3709 the official server does not have substitutes but another server
3710 provides them. Another situation where this is useful is when you would
3711 prefer to download from your organization's substitute server, resorting
3712 to the official server only as a fallback or dismissing it altogether.
3714 You can give Guix a list of substitute server URLs and it will check
3715 them in the specified order. You also need to explicitly authorize the
3716 public keys of substitute servers to instruct Guix to accept the
3717 substitutes they sign.
3719 On Guix System, this is achieved by modifying the configuration of the
3720 @code{guix} service. Since the @code{guix} service is part of the
3721 default lists of services, @code{%base-services} and
3722 @code{%desktop-services}, you can use @code{modify-services} to change
3723 its configuration and add the URLs and substitute keys that you want
3724 (@pxref{Service Reference, @code{modify-services}}).
3726 As an example, suppose you want to fetch substitutes from
3727 @code{guix.example.org} and to authorize the signing key of that server,
3728 in addition to the default @code{@value{SUBSTITUTE-SERVER}}. The
3729 resulting operating system configuration will look something like:
3735 ;; Assume we're starting from '%desktop-services'. Replace it
3736 ;; with the list of services you're actually using.
3737 (modify-services %desktop-services
3738 (guix-service-type config =>
3742 (append (list "https://guix.example.org")
3743 %default-substitute-urls))
3745 (append (list (local-file "./key.pub"))
3746 %default-authorized-guix-keys)))))))
3749 This assumes that the file @file{key.pub} contains the signing key of
3750 @code{guix.example.org}. With this change in place in your operating
3751 system configuration file (say @file{/etc/config.scm}), you can
3752 reconfigure and restart the @code{guix-daemon} service or reboot so the
3753 changes take effect:
3756 $ sudo guix system reconfigure /etc/config.scm
3757 $ sudo herd restart guix-daemon
3760 If you're running Guix on a ``foreign distro'', you would instead take
3761 the following steps to get substitutes from additional servers:
3765 Edit the service configuration file for @code{guix-daemon}; when using
3766 systemd, this is normally
3767 @file{/etc/systemd/system/guix-daemon.service}. Add the
3768 @option{--substitute-urls} option on the @command{guix-daemon} command
3769 line and list the URLs of interest (@pxref{daemon-substitute-urls,
3770 @code{guix-daemon --substitute-urls}}):
3773 @dots{} --substitute-urls='https://guix.example.org https://@value{SUBSTITUTE-SERVER}'
3777 Restart the daemon. For systemd, it goes like this:
3780 systemctl daemon-reload
3781 systemctl restart guix-daemon.service
3785 Authorize the key of the new server (@pxref{Invoking guix archive}):
3788 guix archive --authorize < key.pub
3791 Again this assumes @file{key.pub} contains the public key that
3792 @code{guix.example.org} uses to sign substitutes.
3795 Now you're all set! Substitutes will be preferably taken from
3796 @code{https://guix.example.org}, using @code{@value{SUBSTITUTE-SERVER}}
3797 as a fallback. Of course you can list as many substitute servers as you
3798 like, with the caveat that substitute lookup can be slowed down if too
3799 many servers need to be contacted.
3801 Note that there are also situations where one may want to add the URL of
3802 a substitute server @emph{without} authorizing its key.
3803 @xref{Substitute Authentication}, to understand this fine point.
3805 @node Substitute Authentication
3806 @subsection Substitute Authentication
3808 @cindex digital signatures
3809 Guix detects and raises an error when attempting to use a substitute
3810 that has been tampered with. Likewise, it ignores substitutes that are
3811 not signed, or that are not signed by one of the keys listed in the ACL.
3813 There is one exception though: if an unauthorized server provides
3814 substitutes that are @emph{bit-for-bit identical} to those provided by
3815 an authorized server, then the unauthorized server becomes eligible for
3816 downloads. For example, assume we have chosen two substitute servers
3820 --substitute-urls="https://a.example.org https://b.example.org"
3824 @cindex reproducible builds
3825 If the ACL contains only the key for @samp{b.example.org}, and if
3826 @samp{a.example.org} happens to serve the @emph{exact same} substitutes,
3827 then Guix will download substitutes from @samp{a.example.org} because it
3828 comes first in the list and can be considered a mirror of
3829 @samp{b.example.org}. In practice, independent build machines usually
3830 produce the same binaries, thanks to bit-reproducible builds (see
3833 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3834 (in other words, the server is not authenticated), contrary to what
3835 HTTPS clients such as Web browsers usually do. This is because Guix
3836 authenticates substitute information itself, as explained above, which
3837 is what we care about (whereas X.509 certificates are about
3838 authenticating bindings between domain names and public keys).
3840 @node Proxy Settings
3841 @subsection Proxy Settings
3845 Substitutes are downloaded over HTTP or HTTPS. The @env{http_proxy} and
3846 @env{https_proxy} environment variables can be set in the environment of
3847 @command{guix-daemon} and are honored for downloads of substitutes.
3848 Note that the value of those environment variables in the environment
3849 where @command{guix build}, @command{guix package}, and other client
3850 commands are run has @emph{absolutely no effect}.
3852 @node Substitution Failure
3853 @subsection Substitution Failure
3855 Even when a substitute for a derivation is available, sometimes the
3856 substitution attempt will fail. This can happen for a variety of
3857 reasons: the substitute server might be offline, the substitute may
3858 recently have been deleted, the connection might have been interrupted,
3861 When substitutes are enabled and a substitute for a derivation is
3862 available, but the substitution attempt fails, Guix will attempt to
3863 build the derivation locally depending on whether or not
3864 @option{--fallback} was given (@pxref{fallback-option,, common build
3865 option @option{--fallback}}). Specifically, if @option{--fallback} was
3866 omitted, then no local build will be performed, and the derivation is
3867 considered to have failed. However, if @option{--fallback} was given,
3868 then Guix will attempt to build the derivation locally, and the success
3869 or failure of the derivation depends on the success or failure of the
3870 local build. Note that when substitutes are disabled or no substitute
3871 is available for the derivation in question, a local build will
3872 @emph{always} be performed, regardless of whether or not
3873 @option{--fallback} was given.
3875 To get an idea of how many substitutes are available right now, you can
3876 try running the @command{guix weather} command (@pxref{Invoking guix
3877 weather}). This command provides statistics on the substitutes provided
3880 @node On Trusting Binaries
3881 @subsection On Trusting Binaries
3883 @cindex trust, of pre-built binaries
3884 Today, each individual's control over their own computing is at the
3885 mercy of institutions, corporations, and groups with enough power and
3886 determination to subvert the computing infrastructure and exploit its
3887 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
3888 convenient, we encourage users to also build on their own, or even run
3889 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
3890 interesting target. One way to help is by publishing the software you
3891 build using @command{guix publish} so that others have one more choice
3892 of server to download substitutes from (@pxref{Invoking guix publish}).
3894 Guix has the foundations to maximize build reproducibility
3895 (@pxref{Features}). In most cases, independent builds of a given
3896 package or derivation should yield bit-identical results. Thus, through
3897 a diverse set of independent package builds, we can strengthen the
3898 integrity of our systems. The @command{guix challenge} command aims to
3899 help users assess substitute servers, and to assist developers in
3900 finding out about non-deterministic package builds (@pxref{Invoking guix
3901 challenge}). Similarly, the @option{--check} option of @command{guix
3902 build} allows users to check whether previously-installed substitutes
3903 are genuine by rebuilding them locally (@pxref{build-check,
3904 @command{guix build --check}}).
3906 In the future, we want Guix to have support to publish and retrieve
3907 binaries to/from other users, in a peer-to-peer fashion. If you would
3908 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
3910 @node Packages with Multiple Outputs
3911 @section Packages with Multiple Outputs
3913 @cindex multiple-output packages
3914 @cindex package outputs
3917 Often, packages defined in Guix have a single @dfn{output}---i.e., the
3918 source package leads to exactly one directory in the store. When running
3919 @command{guix install glibc}, one installs the default output of the
3920 GNU libc package; the default output is called @code{out}, but its name
3921 can be omitted as shown in this command. In this particular case, the
3922 default output of @code{glibc} contains all the C header files, shared
3923 libraries, static libraries, Info documentation, and other supporting
3926 Sometimes it is more appropriate to separate the various types of files
3927 produced from a single source package into separate outputs. For
3928 instance, the GLib C library (used by GTK+ and related packages)
3929 installs more than 20 MiB of reference documentation as HTML pages.
3930 To save space for users who do not need it, the documentation goes to a
3931 separate output, called @code{doc}. To install the main GLib output,
3932 which contains everything but the documentation, one would run:
3938 @cindex documentation
3939 The command to install its documentation is:
3942 guix install glib:doc
3945 Some packages install programs with different ``dependency footprints''.
3946 For instance, the WordNet package installs both command-line tools and
3947 graphical user interfaces (GUIs). The former depend solely on the C
3948 library, whereas the latter depend on Tcl/Tk and the underlying X
3949 libraries. In this case, we leave the command-line tools in the default
3950 output, whereas the GUIs are in a separate output. This allows users
3951 who do not need the GUIs to save space. The @command{guix size} command
3952 can help find out about such situations (@pxref{Invoking guix size}).
3953 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
3955 There are several such multiple-output packages in the GNU distribution.
3956 Other conventional output names include @code{lib} for libraries and
3957 possibly header files, @code{bin} for stand-alone programs, and
3958 @code{debug} for debugging information (@pxref{Installing Debugging
3959 Files}). The outputs of a packages are listed in the third column of
3960 the output of @command{guix package --list-available} (@pxref{Invoking
3964 @node Invoking guix gc
3965 @section Invoking @command{guix gc}
3967 @cindex garbage collector
3969 Packages that are installed, but not used, may be @dfn{garbage-collected}.
3970 The @command{guix gc} command allows users to explicitly run the garbage
3971 collector to reclaim space from the @file{/gnu/store} directory. It is
3972 the @emph{only} way to remove files from @file{/gnu/store}---removing
3973 files or directories manually may break it beyond repair!
3976 @cindex garbage collector roots
3977 The garbage collector has a set of known @dfn{roots}: any file under
3978 @file{/gnu/store} reachable from a root is considered @dfn{live} and
3979 cannot be deleted; any other file is considered @dfn{dead} and may be
3980 deleted. The set of garbage collector roots (``GC roots'' for short)
3981 includes default user profiles; by default, the symlinks under
3982 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
3983 added with @command{guix build --root}, for example (@pxref{Invoking
3984 guix build}). The @command{guix gc --list-roots} command lists them.
3986 Prior to running @code{guix gc --collect-garbage} to make space, it is
3987 often useful to remove old generations from user profiles; that way, old
3988 package builds referenced by those generations can be reclaimed. This
3989 is achieved by running @code{guix package --delete-generations}
3990 (@pxref{Invoking guix package}).
3992 Our recommendation is to run a garbage collection periodically, or when
3993 you are short on disk space. For instance, to guarantee that at least
3994 5@tie{}GB are available on your disk, simply run:
4000 It is perfectly safe to run as a non-interactive periodic job
4001 (@pxref{Scheduled Job Execution}, for how to set up such a job).
4002 Running @command{guix gc} with no arguments will collect as
4003 much garbage as it can, but that is often inconvenient: you may find
4004 yourself having to rebuild or re-download software that is ``dead'' from
4005 the GC viewpoint but that is necessary to build other pieces of
4006 software---e.g., the compiler tool chain.
4008 The @command{guix gc} command has three modes of operation: it can be
4009 used to garbage-collect any dead files (the default), to delete specific
4010 files (the @option{--delete} option), to print garbage-collector
4011 information, or for more advanced queries. The garbage collection
4012 options are as follows:
4015 @item --collect-garbage[=@var{min}]
4016 @itemx -C [@var{min}]
4017 Collect garbage---i.e., unreachable @file{/gnu/store} files and
4018 sub-directories. This is the default operation when no option is
4021 When @var{min} is given, stop once @var{min} bytes have been collected.
4022 @var{min} may be a number of bytes, or it may include a unit as a
4023 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
4024 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
4026 When @var{min} is omitted, collect all the garbage.
4028 @item --free-space=@var{free}
4029 @itemx -F @var{free}
4030 Collect garbage until @var{free} space is available under
4031 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
4032 as @code{500MiB}, as described above.
4034 When @var{free} or more is already available in @file{/gnu/store}, do
4035 nothing and exit immediately.
4037 @item --delete-generations[=@var{duration}]
4038 @itemx -d [@var{duration}]
4039 Before starting the garbage collection process, delete all the generations
4040 older than @var{duration}, for all the user profiles; when run as root, this
4041 applies to all the profiles @emph{of all the users}.
4043 For example, this command deletes all the generations of all your profiles
4044 that are older than 2 months (except generations that are current), and then
4045 proceeds to free space until at least 10 GiB are available:
4048 guix gc -d 2m -F 10G
4053 Attempt to delete all the store files and directories specified as
4054 arguments. This fails if some of the files are not in the store, or if
4055 they are still live.
4057 @item --list-failures
4058 List store items corresponding to cached build failures.
4060 This prints nothing unless the daemon was started with
4061 @option{--cache-failures} (@pxref{Invoking guix-daemon,
4062 @option{--cache-failures}}).
4065 List the GC roots owned by the user; when run as root, list @emph{all} the GC
4069 List store items in use by currently running processes. These store
4070 items are effectively considered GC roots: they cannot be deleted.
4072 @item --clear-failures
4073 Remove the specified store items from the failed-build cache.
4075 Again, this option only makes sense when the daemon is started with
4076 @option{--cache-failures}. Otherwise, it does nothing.
4079 Show the list of dead files and directories still present in the
4080 store---i.e., files and directories no longer reachable from any root.
4083 Show the list of live store files and directories.
4087 In addition, the references among existing store files can be queried:
4093 @cindex package dependencies
4094 List the references (respectively, the referrers) of store files given
4100 List the requisites of the store files passed as arguments. Requisites
4101 include the store files themselves, their references, and the references
4102 of these, recursively. In other words, the returned list is the
4103 @dfn{transitive closure} of the store files.
4105 @xref{Invoking guix size}, for a tool to profile the size of the closure
4106 of an element. @xref{Invoking guix graph}, for a tool to visualize
4107 the graph of references.
4111 Return the derivation(s) leading to the given store items
4112 (@pxref{Derivations}).
4114 For example, this command:
4117 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
4121 returns the @file{.drv} file(s) leading to the @code{emacs} package
4122 installed in your profile.
4124 Note that there may be zero matching @file{.drv} files, for instance
4125 because these files have been garbage-collected. There can also be more
4126 than one matching @file{.drv} due to fixed-output derivations.
4129 Lastly, the following options allow you to check the integrity of the
4130 store and to control disk usage.
4134 @item --verify[=@var{options}]
4135 @cindex integrity, of the store
4136 @cindex integrity checking
4137 Verify the integrity of the store.
4139 By default, make sure that all the store items marked as valid in the
4140 database of the daemon actually exist in @file{/gnu/store}.
4142 When provided, @var{options} must be a comma-separated list containing one
4143 or more of @code{contents} and @code{repair}.
4145 When passing @option{--verify=contents}, the daemon computes the
4146 content hash of each store item and compares it against its hash in the
4147 database. Hash mismatches are reported as data corruptions. Because it
4148 traverses @emph{all the files in the store}, this command can take a
4149 long time, especially on systems with a slow disk drive.
4151 @cindex repairing the store
4152 @cindex corruption, recovering from
4153 Using @option{--verify=repair} or @option{--verify=contents,repair}
4154 causes the daemon to try to repair corrupt store items by fetching
4155 substitutes for them (@pxref{Substitutes}). Because repairing is not
4156 atomic, and thus potentially dangerous, it is available only to the
4157 system administrator. A lightweight alternative, when you know exactly
4158 which items in the store are corrupt, is @command{guix build --repair}
4159 (@pxref{Invoking guix build}).
4162 @cindex deduplication
4163 Optimize the store by hard-linking identical files---this is
4164 @dfn{deduplication}.
4166 The daemon performs deduplication after each successful build or archive
4167 import, unless it was started with @option{--disable-deduplication}
4168 (@pxref{Invoking guix-daemon, @option{--disable-deduplication}}). Thus,
4169 this option is primarily useful when the daemon was running with
4170 @option{--disable-deduplication}.
4174 @node Invoking guix pull
4175 @section Invoking @command{guix pull}
4177 @cindex upgrading Guix
4178 @cindex updating Guix
4179 @cindex @command{guix pull}
4181 @cindex security, @command{guix pull}
4182 @cindex authenticity, of code obtained with @command{guix pull}
4183 Packages are installed or upgraded to the latest version available in
4184 the distribution currently available on your local machine. To update
4185 that distribution, along with the Guix tools, you must run @command{guix
4186 pull}: the command downloads the latest Guix source code and package
4187 descriptions, and deploys it. Source code is downloaded from a
4188 @uref{https://git-scm.com, Git} repository, by default the official
4189 GNU@tie{}Guix repository, though this can be customized. @command{guix
4190 pull} ensures that the code it downloads is @emph{authentic} by
4191 verifying that commits are signed by Guix developers.
4193 Specifically, @command{guix pull} downloads code from the @dfn{channels}
4194 (@pxref{Channels}) specified by one of the followings, in this order:
4198 the @option{--channels} option;
4200 the user's @file{~/.config/guix/channels.scm} file;
4202 the system-wide @file{/etc/guix/channels.scm} file;
4204 the built-in default channels specified in the @code{%default-channels}
4208 On completion, @command{guix package} will use packages and package
4209 versions from this just-retrieved copy of Guix. Not only that, but all
4210 the Guix commands and Scheme modules will also be taken from that latest
4211 version. New @command{guix} sub-commands added by the update also
4214 Any user can update their Guix copy using @command{guix pull}, and the
4215 effect is limited to the user who ran @command{guix pull}. For
4216 instance, when user @code{root} runs @command{guix pull}, this has no
4217 effect on the version of Guix that user @code{alice} sees, and vice
4220 The result of running @command{guix pull} is a @dfn{profile} available
4221 under @file{~/.config/guix/current} containing the latest Guix. Thus,
4222 make sure to add it to the beginning of your search path so that you use
4223 the latest version, and similarly for the Info manual
4224 (@pxref{Documentation}):
4227 export PATH="$HOME/.config/guix/current/bin:$PATH"
4228 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
4231 The @option{--list-generations} or @option{-l} option lists past generations
4232 produced by @command{guix pull}, along with details about their provenance:
4236 Generation 1 Jun 10 2018 00:18:18
4238 repository URL: https://git.savannah.gnu.org/git/guix.git
4239 branch: origin/master
4240 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
4242 Generation 2 Jun 11 2018 11:02:49
4244 repository URL: https://git.savannah.gnu.org/git/guix.git
4245 branch: origin/master
4246 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
4247 2 new packages: keepalived, libnfnetlink
4248 6 packages upgraded: emacs-nix-mode@@2.0.4,
4249 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
4250 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
4252 Generation 3 Jun 13 2018 23:31:07 (current)
4254 repository URL: https://git.savannah.gnu.org/git/guix.git
4255 branch: origin/master
4256 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
4257 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
4258 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
4261 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
4262 describe the current status of Guix.
4264 This @code{~/.config/guix/current} profile works exactly like the profiles
4265 created by @command{guix package} (@pxref{Invoking guix package}). That
4266 is, you can list generations, roll back to the previous
4267 generation---i.e., the previous Guix---and so on:
4270 $ guix pull --roll-back
4271 switched from generation 3 to 2
4272 $ guix pull --delete-generations=1
4273 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
4276 You can also use @command{guix package} (@pxref{Invoking guix package})
4277 to manage the profile by naming it explicitly:
4279 $ guix package -p ~/.config/guix/current --roll-back
4280 switched from generation 3 to 2
4281 $ guix package -p ~/.config/guix/current --delete-generations=1
4282 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
4285 The @command{guix pull} command is usually invoked with no arguments,
4286 but it supports the following options:
4289 @item --url=@var{url}
4290 @itemx --commit=@var{commit}
4291 @itemx --branch=@var{branch}
4292 Download code for the @code{guix} channel from the specified @var{url}, at the
4293 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4294 string), or @var{branch}.
4296 @cindex @file{channels.scm}, configuration file
4297 @cindex configuration file for channels
4298 These options are provided for convenience, but you can also specify your
4299 configuration in the @file{~/.config/guix/channels.scm} file or using the
4300 @option{--channels} option (see below).
4302 @item --channels=@var{file}
4303 @itemx -C @var{file}
4304 Read the list of channels from @var{file} instead of
4305 @file{~/.config/guix/channels.scm} or @file{/etc/guix/channels.scm}.
4306 @var{file} must contain Scheme code that
4307 evaluates to a list of channel objects. @xref{Channels}, for more
4310 @cindex channel news
4313 Display the list of packages added or upgraded since the previous
4314 generation, as well as, occasionally, news written by channel authors
4315 for their users (@pxref{Channels, Writing Channel News}).
4317 The package information is the same as displayed upon @command{guix
4318 pull} completion, but without ellipses; it is also similar to the output
4319 of @command{guix pull -l} for the last generation (see below).
4321 @item --list-generations[=@var{pattern}]
4322 @itemx -l [@var{pattern}]
4323 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
4324 is provided, the subset of generations that match @var{pattern}.
4325 The syntax of @var{pattern} is the same as with @code{guix package
4326 --list-generations} (@pxref{Invoking guix package}).
4329 @cindex rolling back
4330 @cindex undoing transactions
4331 @cindex transactions, undoing
4332 Roll back to the previous @dfn{generation} of @file{~/.config/guix/current}---i.e.,
4333 undo the last transaction.
4335 @item --switch-generation=@var{pattern}
4336 @itemx -S @var{pattern}
4338 Switch to a particular generation defined by @var{pattern}.
4340 @var{pattern} may be either a generation number or a number prefixed
4341 with ``+'' or ``-''. The latter means: move forward/backward by a
4342 specified number of generations. For example, if you want to return to
4343 the latest generation after @option{--roll-back}, use
4344 @option{--switch-generation=+1}.
4346 @item --delete-generations[=@var{pattern}]
4347 @itemx -d [@var{pattern}]
4348 When @var{pattern} is omitted, delete all generations except the current
4351 This command accepts the same patterns as @option{--list-generations}.
4352 When @var{pattern} is specified, delete the matching generations. When
4353 @var{pattern} specifies a duration, generations @emph{older} than the
4354 specified duration match. For instance, @option{--delete-generations=1m}
4355 deletes generations that are more than one month old.
4357 If the current generation matches, it is @emph{not} deleted.
4359 Note that deleting generations prevents rolling back to them.
4360 Consequently, this command must be used with care.
4362 @xref{Invoking guix describe}, for a way to display information about the
4363 current generation only.
4365 @item --profile=@var{profile}
4366 @itemx -p @var{profile}
4367 Use @var{profile} instead of @file{~/.config/guix/current}.
4371 Show which channel commit(s) would be used and what would be built or
4372 substituted but do not actually do it.
4374 @item --allow-downgrades
4375 Allow pulling older or unrelated revisions of channels than those
4378 @cindex downgrade attacks, protection against
4379 By default, @command{guix pull} protects against so-called ``downgrade
4380 attacks'' whereby the Git repository of a channel would be reset to an
4381 earlier or unrelated revision of itself, potentially leading you to
4382 install older, known-vulnerable versions of software packages.
4385 Make sure you understand its security implications before using
4386 @option{--allow-downgrades}.
4389 @item --disable-authentication
4390 Allow pulling channel code without authenticating it.
4392 @cindex authentication, of channel code
4393 By default, @command{guix pull} authenticates code downloaded from
4394 channels by verifying that its commits are signed by authorized
4395 developers, and raises an error if this is not the case. This option
4396 instructs it to not perform any such verification.
4399 Make sure you understand its security implications before using
4400 @option{--disable-authentication}.
4403 @item --system=@var{system}
4404 @itemx -s @var{system}
4405 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
4406 the system type of the build host.
4409 Use the bootstrap Guile to build the latest Guix. This option is only
4410 useful to Guix developers.
4413 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
4414 repository and branch to pull from, as well as @emph{additional} repositories
4415 containing package modules that should be deployed. @xref{Channels}, for more
4418 In addition, @command{guix pull} supports all the common build options
4419 (@pxref{Common Build Options}).
4421 @node Invoking guix time-machine
4422 @section Invoking @command{guix time-machine}
4424 @cindex @command{guix time-machine}
4425 @cindex pinning, channels
4426 @cindex replicating Guix
4427 @cindex reproducibility, of Guix
4429 The @command{guix time-machine} command provides access to other
4430 revisions of Guix, for example to install older versions of packages,
4431 or to reproduce a computation in an identical environment. The revision
4432 of Guix to be used is defined by a commit or by a channel
4433 description file created by @command{guix describe}
4434 (@pxref{Invoking guix describe}).
4436 The general syntax is:
4439 guix time-machine @var{options}@dots{} -- @var{command} @var {arg}@dots{}
4442 where @var{command} and @var{arg}@dots{} are passed unmodified to the
4443 @command{guix} command of the specified revision. The @var{options} that define
4444 this revision are the same as for @command{guix pull} (@pxref{Invoking guix pull}):
4447 @item --url=@var{url}
4448 @itemx --commit=@var{commit}
4449 @itemx --branch=@var{branch}
4450 Use the @code{guix} channel from the specified @var{url}, at the
4451 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4452 string), or @var{branch}.
4454 @item --channels=@var{file}
4455 @itemx -C @var{file}
4456 Read the list of channels from @var{file}. @var{file} must contain
4457 Scheme code that evaluates to a list of channel objects.
4458 @xref{Channels} for more information.
4461 As for @command{guix pull}, the absence of any options means that the
4462 latest commit on the master branch will be used. The command
4465 guix time-machine -- build hello
4468 will thus build the package @code{hello} as defined in the master branch,
4469 which is in general a newer revision of Guix than you have installed.
4470 Time travel works in both directions!
4472 Note that @command{guix time-machine} can trigger builds of channels and
4473 their dependencies, and these are controlled by the standard build
4474 options (@pxref{Common Build Options}).
4479 @c TODO: Remove this once we're more confident about API stability.
4481 The functionality described here is a ``technology preview'' as of version
4482 @value{VERSION}. As such, the interface is subject to change.
4486 @cindex composition of Guix revisions
4487 Sometimes you might need to mix packages from the revision of Guix you're
4488 currently running with packages available in a different revision of Guix.
4489 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
4490 revisions in arbitrary ways.
4492 @cindex inferior packages
4493 Technically, an ``inferior'' is essentially a separate Guix process connected
4494 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
4495 @code{(guix inferior)} module allows you to create inferiors and to
4496 communicate with them. It also provides a high-level interface to browse and
4497 manipulate the packages that an inferior provides---@dfn{inferior packages}.
4499 When combined with channels (@pxref{Channels}), inferiors provide a simple way
4500 to interact with a separate revision of Guix. For example, let's assume you
4501 want to install in your profile the current @code{guile} package, along with
4502 the @code{guile-json} as it existed in an older revision of Guix---perhaps
4503 because the newer @code{guile-json} has an incompatible API and you want to
4504 run your code against the old API@. To do that, you could write a manifest for
4505 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
4506 manifest, you would create an inferior for that old Guix revision you care
4507 about, and you would look up the @code{guile-json} package in the inferior:
4510 (use-modules (guix inferior) (guix channels)
4511 (srfi srfi-1)) ;for 'first'
4514 ;; This is the old revision from which we want to
4515 ;; extract guile-json.
4518 (url "https://git.savannah.gnu.org/git/guix.git")
4520 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
4523 ;; An inferior representing the above revision.
4524 (inferior-for-channels channels))
4526 ;; Now create a manifest with the current "guile" package
4527 ;; and the old "guile-json" package.
4529 (list (first (lookup-inferior-packages inferior "guile-json"))
4530 (specification->package "guile")))
4533 On its first run, @command{guix package --manifest} might have to build the
4534 channel you specified before it can create the inferior; subsequent runs will
4535 be much faster because the Guix revision will be cached.
4537 The @code{(guix inferior)} module provides the following procedures to open an
4540 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
4541 [#:cache-directory] [#:ttl]
4542 Return an inferior for @var{channels}, a list of channels. Use the cache at
4543 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4544 This procedure opens a new connection to the build daemon.
4546 As a side effect, this procedure may build or substitute binaries for
4547 @var{channels}, which can take time.
4550 @deffn {Scheme Procedure} open-inferior @var{directory} @
4551 [#:command "bin/guix"]
4552 Open the inferior Guix in @var{directory}, running
4553 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4554 the inferior could not be launched.
4557 @cindex inferior packages
4558 The procedures listed below allow you to obtain and manipulate inferior
4561 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4562 Return the list of packages known to @var{inferior}.
4565 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4567 Return the sorted list of inferior packages matching @var{name} in
4568 @var{inferior}, with highest version numbers first. If @var{version} is true,
4569 return only packages with a version number prefixed by @var{version}.
4572 @deffn {Scheme Procedure} inferior-package? @var{obj}
4573 Return true if @var{obj} is an inferior package.
4576 @deffn {Scheme Procedure} inferior-package-name @var{package}
4577 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4578 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4579 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4580 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4581 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4582 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4583 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4584 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4585 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4586 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4587 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4588 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4589 These procedures are the counterpart of package record accessors
4590 (@pxref{package Reference}). Most of them work by querying the inferior
4591 @var{package} comes from, so the inferior must still be live when you call
4595 Inferior packages can be used transparently like any other package or
4596 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4597 transparently handled by the @code{packages->manifest} procedure, which is
4598 commonly use in manifests (@pxref{Invoking guix package, the
4599 @option{--manifest} option of @command{guix package}}). Thus you can insert
4600 an inferior package pretty much anywhere you would insert a regular package:
4601 in manifests, in the @code{packages} field of your @code{operating-system}
4602 declaration, and so on.
4604 @node Invoking guix describe
4605 @section Invoking @command{guix describe}
4607 @cindex reproducibility
4608 @cindex replicating Guix
4609 Often you may want to answer questions like: ``Which revision of Guix am I
4610 using?'' or ``Which channels am I using?'' This is useful information in many
4611 situations: if you want to @emph{replicate} an environment on a different
4612 machine or user account, if you want to report a bug or to determine what
4613 change in the channels you are using caused it, or if you want to record your
4614 system state for reproducibility purposes. The @command{guix describe}
4615 command answers these questions.
4617 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4618 displays the channel(s) that it was built from, including their repository URL
4619 and commit IDs (@pxref{Channels}):
4623 Generation 10 Sep 03 2018 17:32:44 (current)
4625 repository URL: https://git.savannah.gnu.org/git/guix.git
4627 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4630 If you're familiar with the Git version control system, this is similar in
4631 spirit to @command{git describe}; the output is also similar to that of
4632 @command{guix pull --list-generations}, but limited to the current generation
4633 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4634 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4635 information is all it takes to describe the revision of Guix you're using, and
4636 also to replicate it.
4638 To make it easier to replicate Guix, @command{guix describe} can also be asked
4639 to return a list of channels instead of the human-readable description above:
4642 $ guix describe -f channels
4645 (url "https://git.savannah.gnu.org/git/guix.git")
4647 "e0fa68c7718fffd33d81af415279d6ddb518f727")
4649 (make-channel-introduction
4650 "9edb3f66fd807b096b48283debdcddccfea34bad"
4651 (openpgp-fingerprint
4652 "BBB0 2DDF 2CEA F6A8 0D1D E643 A2A0 6DF2 A33A 54FA")))))
4656 You can save this to a file and feed it to @command{guix pull -C} on some
4657 other machine or at a later point in time, which will instantiate @emph{this
4658 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4659 From there on, since you're able to deploy the same revision of Guix, you can
4660 just as well @emph{replicate a complete software environment}. We humbly
4661 think that this is @emph{awesome}, and we hope you'll like it too!
4663 The details of the options supported by @command{guix describe} are as
4667 @item --format=@var{format}
4668 @itemx -f @var{format}
4669 Produce output in the specified @var{format}, one of:
4673 produce human-readable output;
4675 produce a list of channel specifications that can be passed to @command{guix
4676 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4678 @item channels-sans-intro
4679 like @code{channels}, but omit the @code{introduction} field; use it to
4680 produce a channel specification suitable for Guix version 1.1.0 or
4681 earlier---the @code{introduction} field has to do with channel
4682 authentication (@pxref{Channels, Channel Authentication}) and is not
4683 supported by these older versions;
4686 produce a list of channel specifications in JSON format;
4688 produce a list of channel specifications in Recutils format.
4691 @item --list-formats
4692 Display available formats for @option{--format} option.
4694 @item --profile=@var{profile}
4695 @itemx -p @var{profile}
4696 Display information about @var{profile}.
4699 @node Invoking guix archive
4700 @section Invoking @command{guix archive}
4702 @cindex @command{guix archive}
4704 The @command{guix archive} command allows users to @dfn{export} files
4705 from the store into a single archive, and to later @dfn{import} them on
4706 a machine that runs Guix.
4707 In particular, it allows store files to be transferred from one machine
4708 to the store on another machine.
4711 If you're looking for a way to produce archives in a format suitable for
4712 tools other than Guix, @pxref{Invoking guix pack}.
4715 @cindex exporting store items
4716 To export store files as an archive to standard output, run:
4719 guix archive --export @var{options} @var{specifications}...
4722 @var{specifications} may be either store file names or package
4723 specifications, as for @command{guix package} (@pxref{Invoking guix
4724 package}). For instance, the following command creates an archive
4725 containing the @code{gui} output of the @code{git} package and the main
4726 output of @code{emacs}:
4729 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4732 If the specified packages are not built yet, @command{guix archive}
4733 automatically builds them. The build process may be controlled with the
4734 common build options (@pxref{Common Build Options}).
4736 To transfer the @code{emacs} package to a machine connected over SSH,
4740 guix archive --export -r emacs | ssh the-machine guix archive --import
4744 Similarly, a complete user profile may be transferred from one machine
4745 to another like this:
4748 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4749 ssh the-machine guix archive --import
4753 However, note that, in both examples, all of @code{emacs} and the
4754 profile as well as all of their dependencies are transferred (due to
4755 @option{-r}), regardless of what is already available in the store on
4756 the target machine. The @option{--missing} option can help figure out
4757 which items are missing from the target store. The @command{guix copy}
4758 command simplifies and optimizes this whole process, so this is probably
4759 what you should use in this case (@pxref{Invoking guix copy}).
4761 @cindex nar, archive format
4762 @cindex normalized archive (nar)
4763 @cindex nar bundle, archive format
4764 Each store item is written in the @dfn{normalized archive} or @dfn{nar}
4765 format (described below), and the output of @command{guix archive
4766 --export} (and input of @command{guix archive --import}) is a @dfn{nar
4770 comparable in spirit to `tar', but with differences
4771 that make it more appropriate for our purposes. First, rather than
4772 recording all Unix metadata for each file, the nar format only mentions
4773 the file type (regular, directory, or symbolic link); Unix permissions
4774 and owner/group are dismissed. Second, the order in which directory
4775 entries are stored always follows the order of file names according to
4776 the C locale collation order. This makes archive production fully
4779 That nar bundle format is essentially the concatenation of zero or more
4780 nars along with metadata for each store item it contains: its file name,
4781 references, corresponding derivation, and a digital signature.
4783 When exporting, the daemon digitally signs the contents of the archive,
4784 and that digital signature is appended. When importing, the daemon
4785 verifies the signature and rejects the import in case of an invalid
4786 signature or if the signing key is not authorized.
4787 @c FIXME: Add xref to daemon doc about signatures.
4789 The main options are:
4793 Export the specified store files or packages (see below). Write the
4794 resulting archive to the standard output.
4796 Dependencies are @emph{not} included in the output, unless
4797 @option{--recursive} is passed.
4801 When combined with @option{--export}, this instructs @command{guix archive}
4802 to include dependencies of the given items in the archive. Thus, the
4803 resulting archive is self-contained: it contains the closure of the
4804 exported store items.
4807 Read an archive from the standard input, and import the files listed
4808 therein into the store. Abort if the archive has an invalid digital
4809 signature, or if it is signed by a public key not among the authorized
4810 keys (see @option{--authorize} below).
4813 Read a list of store file names from the standard input, one per line,
4814 and write on the standard output the subset of these files missing from
4817 @item --generate-key[=@var{parameters}]
4818 @cindex signing, archives
4819 Generate a new key pair for the daemon. This is a prerequisite before
4820 archives can be exported with @option{--export}. This
4821 operation is usually instantaneous but it can take time if the system's
4822 entropy pool needs to be refilled. On Guix System,
4823 @code{guix-service-type} takes care of generating this key pair the
4826 The generated key pair is typically stored under @file{/etc/guix}, in
4827 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
4828 key, which must be kept secret). When @var{parameters} is omitted,
4829 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
4830 versions before 1.6.0, it is a 4096-bit RSA key.
4831 Alternatively, @var{parameters} can specify
4832 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
4833 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
4834 Libgcrypt Reference Manual}).
4837 @cindex authorizing, archives
4838 Authorize imports signed by the public key passed on standard input.
4839 The public key must be in ``s-expression advanced format''---i.e., the
4840 same format as the @file{signing-key.pub} file.
4842 The list of authorized keys is kept in the human-editable file
4843 @file{/etc/guix/acl}. The file contains
4844 @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
4845 s-expressions''} and is structured as an access-control list in the
4846 @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
4849 @item --extract=@var{directory}
4850 @itemx -x @var{directory}
4851 Read a single-item archive as served by substitute servers
4852 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
4853 low-level operation needed in only very narrow use cases; see below.
4855 For example, the following command extracts the substitute for Emacs
4856 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
4860 https://@value{SUBSTITUTE-SERVER}/nar/gzip/@dots{}-emacs-24.5 \
4861 | gunzip | guix archive -x /tmp/emacs
4864 Single-item archives are different from multiple-item archives produced
4865 by @command{guix archive --export}; they contain a single store item,
4866 and they do @emph{not} embed a signature. Thus this operation does
4867 @emph{no} signature verification and its output should be considered
4870 The primary purpose of this operation is to facilitate inspection of
4871 archive contents coming from possibly untrusted substitute servers
4872 (@pxref{Invoking guix challenge}).
4876 Read a single-item archive as served by substitute servers
4877 (@pxref{Substitutes}) and print the list of files it contains, as in
4882 https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-emacs-26.3 \
4883 | lzip -d | guix archive -t
4888 @c *********************************************************************
4893 @cindex @file{channels.scm}, configuration file
4894 @cindex configuration file for channels
4895 @cindex @command{guix pull}, configuration file
4896 @cindex configuration of @command{guix pull}
4897 Guix and its package collection are updated by running @command{guix pull}
4898 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
4899 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
4900 customized by defining @dfn{channels} in the
4901 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
4902 of a Git repository to be deployed, and @command{guix pull} can be instructed
4903 to pull from one or more channels. In other words, channels can be used
4904 to @emph{customize} and to @emph{extend} Guix, as we will see below.
4905 Guix is able to take into account security concerns and deal with authenticated
4909 * Specifying Additional Channels:: Extending the package collection.
4910 * Using a Custom Guix Channel:: Using a customized Guix.
4911 * Replicating Guix:: Running the @emph{exact same} Guix.
4912 * Channel Authentication:: How Guix verifies what it fetches.
4913 * Creating a Channel:: How to write your custom channel.
4914 * Package Modules in a Sub-directory:: Specifying the channel's package modules location.
4915 * Declaring Channel Dependencies:: How to depend on other channels.
4916 * Specifying Channel Authorizations:: Defining channel authors authorizations.
4917 * Primary URL:: Distinguishing mirror to original.
4918 * Writing Channel News:: Communicating information to channel's users.
4921 @node Specifying Additional Channels
4922 @section Specifying Additional Channels
4924 @cindex extending the package collection (channels)
4925 @cindex variant packages (channels)
4926 You can specify @emph{additional channels} to pull from. To use a channel, write
4927 @code{~/.config/guix/channels.scm} to instruct @command{guix pull} to pull from it
4928 @emph{in addition} to the default Guix channel(s):
4930 @vindex %default-channels
4932 ;; Add variant packages to those Guix provides.
4934 (name 'variant-packages)
4935 (url "https://example.org/variant-packages.git"))
4940 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
4941 add a channel the list of channels that the variable @code{%default-channels}
4942 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
4943 Manual}). With this file in place, @command{guix pull} builds not only Guix
4944 but also the package modules from your own repository. The result in
4945 @file{~/.config/guix/current} is the union of Guix with your own package
4949 $ guix pull --list-generations
4951 Generation 19 Aug 27 2018 16:20:48
4953 repository URL: https://git.savannah.gnu.org/git/guix.git
4955 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
4956 variant-packages dd3df5e
4957 repository URL: https://example.org/variant-packages.git
4959 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
4960 11 new packages: variant-gimp, variant-emacs-with-cool-features, @dots{}
4961 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
4965 The output of @command{guix pull} above shows that Generation@tie{}19 includes
4966 both Guix and packages from the @code{variant-personal-packages} channel. Among
4967 the new and upgraded packages that are listed, some like @code{variant-gimp} and
4968 @code{variant-emacs-with-cool-features} might come from
4969 @code{variant-packages}, while others come from the Guix default channel.
4971 @node Using a Custom Guix Channel
4972 @section Using a Custom Guix Channel
4974 The channel called @code{guix} specifies where Guix itself---its command-line
4975 tools as well as its package collection---should be downloaded. For instance,
4976 suppose you want to update from another copy of the Guix repository at
4977 @code{example.org}, and specifically the @code{super-hacks} branch, you can
4978 write in @code{~/.config/guix/channels.scm} this specification:
4981 ;; Tell 'guix pull' to use another repo.
4984 (url "https://example.org/another-guix.git")
4985 (branch "super-hacks")))
4989 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
4990 branch of the repository at @code{example.org}. The authentication concern is
4991 addressed below ((@pxref{Channel Authentication}).
4993 @node Replicating Guix
4994 @section Replicating Guix
4996 @cindex pinning, channels
4997 @cindex replicating Guix
4998 @cindex reproducibility, of Guix
4999 The @command{guix pull --list-generations} output above shows precisely which
5000 commits were used to build this instance of Guix. We can thus replicate it,
5001 say, on another machine, by providing a channel specification in
5002 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
5005 ;; Deploy specific commits of my channels of interest.
5008 (url "https://git.savannah.gnu.org/git/guix.git")
5009 (commit "6298c3ffd9654d3231a6f25390b056483e8f407c"))
5011 (name 'variant-packages)
5012 (url "https://example.org/variant-packages.git")
5013 (commit "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
5016 The @command{guix describe --format=channels} command can even generate this
5017 list of channels directly (@pxref{Invoking guix describe}). The resulting
5018 file can be used with the -C options of @command{guix pull}
5019 (@pxref{Invoking guix pull}) or @command{guix time-machine}
5020 (@pxref{Invoking guix time-machine}).
5022 At this point the two machines run the @emph{exact same Guix}, with access to
5023 the @emph{exact same packages}. The output of @command{guix build gimp} on
5024 one machine will be exactly the same, bit for bit, as the output of the same
5025 command on the other machine. It also means both machines have access to all
5026 the source code of Guix and, transitively, to all the source code of every
5029 This gives you super powers, allowing you to track the provenance of binary
5030 artifacts with very fine grain, and to reproduce software environments at
5031 will---some sort of ``meta reproducibility'' capabilities, if you will.
5032 @xref{Inferiors}, for another way to take advantage of these super powers.
5034 @node Channel Authentication
5035 @section Channel Authentication
5037 @anchor{channel-authentication}
5038 @cindex authentication, of channel code
5039 The @command{guix pull} and @command{guix time-machine} commands
5040 @dfn{authenticate} the code retrieved from channels: they make sure each
5041 commit that is fetched is signed by an authorized developer. The goal
5042 is to protect from unauthorized modifications to the channel that would
5043 lead users to run malicious code.
5045 As a user, you must provide a @dfn{channel introduction} in your
5046 channels file so that Guix knows how to authenticate its first commit.
5047 A channel specification, including its introduction, looks something
5052 (name 'some-channel)
5053 (url "https://example.org/some-channel.git")
5055 (make-channel-introduction
5056 "6f0d8cc0d88abb59c324b2990bfee2876016bb86"
5057 (openpgp-fingerprint
5058 "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
5061 The specification above shows the name and URL of the channel. The call
5062 to @code{make-channel-introduction} above specifies that authentication
5063 of this channel starts at commit @code{6f0d8cc@dots{}}, which is signed
5064 by the OpenPGP key with fingerprint @code{CABB A931@dots{}}.
5066 For the main channel, called @code{guix}, you automatically get that
5067 information from your Guix installation. For other channels, include
5068 the channel introduction provided by the channel authors in your
5069 @file{channels.scm} file. Make sure you retrieve the channel
5070 introduction from a trusted source since that is the root of your trust.
5072 If you're curious about the authentication mechanics, read on!
5074 @node Creating a Channel
5075 @section Creating a Channel
5077 @cindex personal packages (channels)
5078 @cindex channels, for personal packages
5079 Let's say you have a bunch of custom package variants or personal packages
5080 that you think would make little sense to contribute to the Guix project, but
5081 would like to have these packages transparently available to you at the
5082 command line. You would first write modules containing those package
5083 definitions (@pxref{Package Modules}), maintain them in a Git repository, and
5084 then you and anyone else can use it as an additional channel to get packages
5087 @c What follows stems from discussions at
5088 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
5089 @c earlier discussions on guix-devel@gnu.org.
5091 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
5092 publish your personal channel to the world, we would like to share a few words
5097 Before publishing a channel, please consider contributing your package
5098 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
5099 to free software of all sorts, and packages in Guix proper are readily
5100 available to all Guix users and benefit from the project's quality assurance
5104 When you maintain package definitions outside Guix, we, Guix developers,
5105 consider that @emph{the compatibility burden is on you}. Remember that
5106 package modules and package definitions are just Scheme code that uses various
5107 programming interfaces (APIs). We want to remain free to change these APIs to
5108 keep improving Guix, possibly in ways that break your channel. We never
5109 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
5113 Corollary: if you're using an external channel and that channel breaks, please
5114 @emph{report the issue to the channel authors}, not to the Guix project.
5117 You've been warned! Having said this, we believe external channels are a
5118 practical way to exert your freedom to augment Guix' package collection and to
5119 share your improvements, which are basic tenets of
5120 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
5121 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
5124 To create a channel, create a Git repository containing your own package
5125 modules and make it available. The repository can contain anything, but a
5126 useful channel will contain Guile modules that export packages. Once you
5127 start using a channel, Guix will behave as if the root directory of that
5128 channel's Git repository has been added to the Guile load path (@pxref{Load
5129 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
5130 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
5131 module, then the module will be available under the name @code{(my-packages
5132 my-tools)}, and you will be able to use it like any other module
5133 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
5135 As a channel author, consider bundling authentication material with your
5136 channel so that users can authenticate it. @xref{Channel
5137 Authentication}, and @ref{Specifying Channel Authorizations}, for info
5141 @node Package Modules in a Sub-directory
5142 @section Package Modules in a Sub-directory
5144 @cindex subdirectory, channels
5145 As a channel author, you may want to keep your channel modules in a
5146 sub-directory. If your modules are in the sub-directory @file{guix}, you must
5147 add a meta-data file @file{.guix-channel} that contains:
5155 @node Declaring Channel Dependencies
5156 @section Declaring Channel Dependencies
5158 @cindex dependencies, channels
5159 @cindex meta-data, channels
5160 Channel authors may decide to augment a package collection provided by other
5161 channels. They can declare their channel to be dependent on other channels in
5162 a meta-data file @file{.guix-channel}, which is to be placed in the root of
5163 the channel repository.
5165 The meta-data file should contain a simple S-expression like this:
5172 (name 'some-collection)
5173 (url "https://example.org/first-collection.git")
5175 ;; The 'introduction' bit below is optional: you would
5176 ;; provide it for dependencies that can be authenticated.
5178 (channel-introduction
5180 (commit "a8883b58dc82e167c96506cf05095f37c2c2c6cd")
5181 (signer "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
5183 (name 'some-other-collection)
5184 (url "https://example.org/second-collection.git")
5185 (branch "testing"))))
5188 In the above example this channel is declared to depend on two other channels,
5189 which will both be fetched automatically. The modules provided by the channel
5190 will be compiled in an environment where the modules of all these declared
5191 channels are available.
5193 For the sake of reliability and maintainability, you should avoid dependencies
5194 on channels that you don't control, and you should aim to keep the number of
5195 dependencies to a minimum.
5197 @node Specifying Channel Authorizations
5198 @section Specifying Channel Authorizations
5200 @cindex channel authorizations
5201 @anchor{channel-authorizations}
5202 As we saw above, Guix ensures the source code it pulls from channels
5203 comes from authorized developers. As a channel author, you need to
5204 specify the list of authorized developers in the
5205 @file{.guix-authorizations} file in the channel's Git repository. The
5206 authentication rule is simple: each commit must be signed by a key
5207 listed in the @file{.guix-authorizations} file of its parent
5208 commit(s)@footnote{Git commits form a @dfn{directed acyclic graph}
5209 (DAG). Each commit can have zero or more parents; ``regular'' commits
5210 have one parent and merge commits have two parent commits. Read
5211 @uref{https://eagain.net/articles/git-for-computer-scientists/, @i{Git
5212 for Computer Scientists}} for a great overview.} The
5213 @file{.guix-authorizations} file looks like this:
5216 ;; Example '.guix-authorizations' file.
5219 (version 0) ;current file format version
5221 (("AD17 A21E F8AE D8F1 CC02 DBD9 F8AE D8F1 765C 61E3"
5223 ("2A39 3FFF 68F4 EF7A 3D29 12AF 68F4 EF7A 22FB B2D5"
5225 ("CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"
5229 Each fingerprint is followed by optional key/value pairs, as in the
5230 example above. Currently these key/value pairs are ignored.
5232 This authentication rule creates a chicken-and-egg issue: how do we
5233 authenticate the first commit? Related to that: how do we deal with
5234 channels whose repository history contains unsigned commits and lack
5235 @file{.guix-authorizations}? And how do we fork existing channels?
5237 @cindex channel introduction
5238 Channel introductions answer these questions by describing the first
5239 commit of a channel that should be authenticated. The first time a
5240 channel is fetched with @command{guix pull} or @command{guix
5241 time-machine}, the command looks up the introductory commit and verifies
5242 that it is signed by the specified OpenPGP key. From then on, it
5243 authenticates commits according to the rule above.
5245 Additionally, your channel must provide all the OpenPGP keys that were
5246 ever mentioned in @file{.guix-authorizations}, stored as @file{.key}
5247 files, which can be either binary or ``ASCII-armored''. By default,
5248 those @file{.key} files are searched for in the branch named
5249 @code{keyring} but you can specify a different branch name in
5250 @code{.guix-channel} like so:
5255 (keyring-reference "my-keyring-branch"))
5258 To summarize, as the author of a channel, there are three things you have
5259 to do to allow users to authenticate your code:
5263 Export the OpenPGP keys of past and present committers with @command{gpg
5264 --export} and store them in @file{.key} files, by default in a branch
5265 named @code{keyring} (we recommend making it an @dfn{orphan branch}).
5268 Introduce an initial @file{.guix-authorizations} in the channel's
5269 repository. Do that in a signed commit (@pxref{Commit Access}, for
5270 information on how to sign Git commits.)
5273 Advertise the channel introduction, for instance on your channel's web
5274 page. The channel introduction, as we saw above, is the commit/key
5275 pair---i.e., the commit that introduced @file{.guix-authorizations}, and
5276 the fingerprint of the OpenPGP used to sign it.
5279 Before pushing to your public Git repository, you can run @command{guix
5280 git-authenticate} to verify that you did sign all the commits you are
5281 about to push with an authorized key:
5284 guix git authenticate @var{commit} @var{signer}
5288 where @var{commit} and @var{signer} are your channel introduction.
5289 @xref{Invoking guix git authenticate}, for details.
5291 Publishing a signed channel requires discipline: any mistake, such as an
5292 unsigned commit or a commit signed by an unauthorized key, will prevent
5293 users from pulling from your channel---well, that's the whole point of
5294 authentication! Pay attention to merges in particular: merge commits
5295 are considered authentic if and only if they are signed by a key present
5296 in the @file{.guix-authorizations} file of @emph{both} branches.
5299 @section Primary URL
5301 @cindex primary URL, channels
5302 Channel authors can indicate the primary URL of their channel's Git
5303 repository in the @file{.guix-channel} file, like so:
5308 (url "https://example.org/guix.git"))
5311 This allows @command{guix pull} to determine whether it is pulling code
5312 from a mirror of the channel; when that is the case, it warns the user
5313 that the mirror might be stale and displays the primary URL. That way,
5314 users cannot be tricked into fetching code from a stale mirror that does
5315 not receive security updates.
5317 This feature only makes sense for authenticated repositories, such as
5318 the official @code{guix} channel, for which @command{guix pull} ensures
5319 the code it fetches is authentic.
5321 @node Writing Channel News
5322 @section Writing Channel News
5324 @cindex news, for channels
5325 Channel authors may occasionally want to communicate to their users
5326 information about important changes in the channel. You'd send them all
5327 an email, but that's not convenient.
5329 Instead, channels can provide a @dfn{news file}; when the channel users
5330 run @command{guix pull}, that news file is automatically read and
5331 @command{guix pull --news} can display the announcements that correspond
5332 to the new commits that have been pulled, if any.
5334 To do that, channel authors must first declare the name of the news file
5335 in their @file{.guix-channel} file:
5340 (news-file "etc/news.txt"))
5343 The news file itself, @file{etc/news.txt} in this example, must look
5344 something like this:
5349 (entry (tag "the-bug-fix")
5350 (title (en "Fixed terrible bug")
5352 (body (en "@@emph@{Good news@}! It's fixed!")
5353 (eo "Certe ĝi pli bone funkcias nun!")))
5354 (entry (commit "bdcabe815cd28144a2d2b4bc3c5057b051fa9906")
5355 (title (en "Added a great package")
5356 (ca "Què vol dir guix?"))
5357 (body (en "Don't miss the @@code@{hello@} package!"))))
5360 While the news file is using the Scheme syntax, avoid naming it with a
5361 @file{.scm} extension or else it will get picked up when building the
5362 channel and yield an error since it is not a valid module.
5363 Alternatively, you can move the channel module to a subdirectory and
5364 store the news file in another directory.
5366 The file consists of a list of @dfn{news entries}. Each entry is
5367 associated with a commit or tag: it describes changes made in this
5368 commit, possibly in preceding commits as well. Users see entries only
5369 the first time they obtain the commit the entry refers to.
5371 The @code{title} field should be a one-line summary while @code{body}
5372 can be arbitrarily long, and both can contain Texinfo markup
5373 (@pxref{Overview,,, texinfo, GNU Texinfo}). Both the title and body are
5374 a list of language tag/message tuples, which allows @command{guix pull}
5375 to display news in the language that corresponds to the user's locale.
5377 If you want to translate news using a gettext-based workflow, you can
5378 extract translatable strings with @command{xgettext} (@pxref{xgettext
5379 Invocation,,, gettext, GNU Gettext Utilities}). For example, assuming
5380 you write news entries in English first, the command below creates a PO
5381 file containing the strings to translate:
5384 xgettext -o news.po -l scheme -ken etc/news.txt
5387 To sum up, yes, you could use your channel as a blog. But beware, this
5388 is @emph{not quite} what your users might expect.
5391 @c *********************************************************************
5393 @chapter Development
5395 @cindex software development
5396 If you are a software developer, Guix provides tools that you should find
5397 helpful---independently of the language you're developing in. This is what
5398 this chapter is about.
5400 The @command{guix environment} command provides a convenient way to set up
5401 @dfn{development environments} containing all the dependencies and tools
5402 necessary to work on the software package of your choice. The @command{guix
5403 pack} command allows you to create @dfn{application bundles} that can be
5404 easily distributed to users who do not run Guix.
5407 * Invoking guix environment:: Setting up development environments.
5408 * Invoking guix pack:: Creating software bundles.
5409 * The GCC toolchain:: Working with languages supported by GCC.
5410 * Invoking guix git authenticate:: Authenticating Git repositories.
5413 @node Invoking guix environment
5414 @section Invoking @command{guix environment}
5416 @cindex reproducible build environments
5417 @cindex development environments
5418 @cindex @command{guix environment}
5419 @cindex environment, package build environment
5420 The purpose of @command{guix environment} is to assist hackers in
5421 creating reproducible development environments without polluting their
5422 package profile. The @command{guix environment} tool takes one or more
5423 packages, builds all of their inputs, and creates a shell
5424 environment to use them.
5426 The general syntax is:
5429 guix environment @var{options} @var{package}@dots{}
5432 The following example spawns a new shell set up for the development of
5436 guix environment guile
5439 If the needed dependencies are not built yet, @command{guix environment}
5440 automatically builds them. The environment of the new shell is an
5441 augmented version of the environment that @command{guix environment} was
5442 run in. It contains the necessary search paths for building the given
5443 package added to the existing environment variables. To create
5444 a ``pure'' environment, in which the original environment variables have
5445 been unset, use the @option{--pure} option@footnote{Users sometimes
5446 wrongfully augment environment variables such as @env{PATH} in their
5447 @file{~/.bashrc} file. As a consequence, when @command{guix
5448 environment} launches it, Bash may read @file{~/.bashrc}, thereby
5449 introducing ``impurities'' in these environment variables. It is an
5450 error to define such environment variables in @file{.bashrc}; instead,
5451 they should be defined in @file{.bash_profile}, which is sourced only by
5452 log-in shells. @xref{Bash Startup Files,,, bash, The GNU Bash Reference
5453 Manual}, for details on Bash start-up files.}.
5455 @vindex GUIX_ENVIRONMENT
5456 @command{guix environment} defines the @env{GUIX_ENVIRONMENT}
5457 variable in the shell it spawns; its value is the file name of the
5458 profile of this environment. This allows users to, say, define a
5459 specific prompt for development environments in their @file{.bashrc}
5460 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
5463 if [ -n "$GUIX_ENVIRONMENT" ]
5465 export PS1="\u@@\h \w [dev]\$ "
5470 ...@: or to browse the profile:
5473 $ ls "$GUIX_ENVIRONMENT/bin"
5476 Additionally, more than one package may be specified, in which case the
5477 union of the inputs for the given packages are used. For example, the
5478 command below spawns a shell where all of the dependencies of both Guile
5479 and Emacs are available:
5482 guix environment guile emacs
5485 Sometimes an interactive shell session is not desired. An arbitrary
5486 command may be invoked by placing the @code{--} token to separate the
5487 command from the rest of the arguments:
5490 guix environment guile -- make -j4
5493 In other situations, it is more convenient to specify the list of
5494 packages needed in the environment. For example, the following command
5495 runs @command{python} from an environment containing Python@tie{}2.7 and
5499 guix environment --ad-hoc python2-numpy python-2.7 -- python
5502 Furthermore, one might want the dependencies of a package and also some
5503 additional packages that are not build-time or runtime dependencies, but
5504 are useful when developing nonetheless. Because of this, the
5505 @option{--ad-hoc} flag is positional. Packages appearing before
5506 @option{--ad-hoc} are interpreted as packages whose dependencies will be
5507 added to the environment. Packages appearing after are interpreted as
5508 packages that will be added to the environment directly. For example,
5509 the following command creates a Guix development environment that
5510 additionally includes Git and strace:
5513 guix environment --pure guix --ad-hoc git strace
5517 Sometimes it is desirable to isolate the environment as much as
5518 possible, for maximal purity and reproducibility. In particular, when
5519 using Guix on a host distro that is not Guix System, it is desirable to
5520 prevent access to @file{/usr/bin} and other system-wide resources from
5521 the development environment. For example, the following command spawns
5522 a Guile REPL in a ``container'' where only the store and the current
5523 working directory are mounted:
5526 guix environment --ad-hoc --container guile -- guile
5530 The @option{--container} option requires Linux-libre 3.19 or newer.
5533 @cindex certificates
5534 Another typical use case for containers is to run security-sensitive
5535 applications such as a web browser. To run Eolie, we must expose and
5536 share some files and directories; we include @code{nss-certs} and expose
5537 @file{/etc/ssl/certs/} for HTTPS authentication; finally we preserve the
5538 @env{DISPLAY} environment variable since containerized graphical
5539 applications won't display without it.
5542 guix environment --preserve='^DISPLAY$' --container --network \
5543 --expose=/etc/machine-id \
5544 --expose=/etc/ssl/certs/ \
5545 --share=$HOME/.local/share/eolie/=$HOME/.local/share/eolie/ \
5546 --ad-hoc eolie nss-certs dbus -- eolie
5549 The available options are summarized below.
5552 @item --root=@var{file}
5553 @itemx -r @var{file}
5554 @cindex persistent environment
5555 @cindex garbage collector root, for environments
5556 Make @var{file} a symlink to the profile for this environment, and
5557 register it as a garbage collector root.
5559 This is useful if you want to protect your environment from garbage
5560 collection, to make it ``persistent''.
5562 When this option is omitted, the environment is protected from garbage
5563 collection only for the duration of the @command{guix environment}
5564 session. This means that next time you recreate the same environment,
5565 you could have to rebuild or re-download packages. @xref{Invoking guix
5566 gc}, for more on GC roots.
5568 @item --expression=@var{expr}
5569 @itemx -e @var{expr}
5570 Create an environment for the package or list of packages that
5571 @var{expr} evaluates to.
5573 For example, running:
5576 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
5579 starts a shell with the environment for this specific variant of the
5585 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
5588 starts a shell with all the base system packages available.
5590 The above commands only use the default output of the given packages.
5591 To select other outputs, two element tuples can be specified:
5594 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
5597 @item --load=@var{file}
5598 @itemx -l @var{file}
5599 Create an environment for the package or list of packages that the code
5600 within @var{file} evaluates to.
5602 As an example, @var{file} might contain a definition like this
5603 (@pxref{Defining Packages}):
5606 @verbatiminclude environment-gdb.scm
5609 @item --manifest=@var{file}
5610 @itemx -m @var{file}
5611 Create an environment for the packages contained in the manifest object
5612 returned by the Scheme code in @var{file}. This option can be repeated
5613 several times, in which case the manifests are concatenated.
5615 This is similar to the same-named option in @command{guix package}
5616 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
5620 Include all specified packages in the resulting environment, as if an
5621 @i{ad hoc} package were defined with them as inputs. This option is
5622 useful for quickly creating an environment without having to write a
5623 package expression to contain the desired inputs.
5625 For instance, the command:
5628 guix environment --ad-hoc guile guile-sdl -- guile
5631 runs @command{guile} in an environment where Guile and Guile-SDL are
5634 Note that this example implicitly asks for the default output of
5635 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
5636 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
5637 of @code{glib} (@pxref{Packages with Multiple Outputs}).
5639 This option may be composed with the default behavior of @command{guix
5640 environment}. Packages appearing before @option{--ad-hoc} are
5641 interpreted as packages whose dependencies will be added to the
5642 environment, the default behavior. Packages appearing after are
5643 interpreted as packages that will be added to the environment directly.
5646 Unset existing environment variables when building the new environment, except
5647 those specified with @option{--preserve} (see below). This has the effect of
5648 creating an environment in which search paths only contain package inputs.
5650 @item --preserve=@var{regexp}
5651 @itemx -E @var{regexp}
5652 When used alongside @option{--pure}, preserve the environment variables
5653 matching @var{regexp}---in other words, put them on a ``white list'' of
5654 environment variables that must be preserved. This option can be repeated
5658 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
5662 This example runs @command{mpirun} in a context where the only environment
5663 variables defined are @env{PATH}, environment variables whose name starts
5664 with @samp{SLURM}, as well as the usual ``precious'' variables (@env{HOME},
5667 @item --search-paths
5668 Display the environment variable definitions that make up the
5671 @item --system=@var{system}
5672 @itemx -s @var{system}
5673 Attempt to build for @var{system}---e.g., @code{i686-linux}.
5678 Run @var{command} within an isolated container. The current working
5679 directory outside the container is mapped inside the container.
5680 Additionally, unless overridden with @option{--user}, a dummy home
5681 directory is created that matches the current user's home directory, and
5682 @file{/etc/passwd} is configured accordingly.
5684 The spawned process runs as the current user outside the container. Inside
5685 the container, it has the same UID and GID as the current user, unless
5686 @option{--user} is passed (see below).
5690 For containers, share the network namespace with the host system.
5691 Containers created without this flag only have access to the loopback
5694 @item --link-profile
5696 For containers, link the environment profile to @file{~/.guix-profile}
5697 within the container and set @code{GUIX_ENVIRONMENT} to that.
5698 This is equivalent to making @file{~/.guix-profile} a symlink to the
5699 actual profile within the container.
5700 Linking will fail and abort the environment if the directory already
5701 exists, which will certainly be the case if @command{guix environment}
5702 was invoked in the user's home directory.
5704 Certain packages are configured to look in @file{~/.guix-profile} for
5705 configuration files and data;@footnote{For example, the
5706 @code{fontconfig} package inspects @file{~/.guix-profile/share/fonts}
5707 for additional fonts.} @option{--link-profile} allows these programs to
5708 behave as expected within the environment.
5710 @item --user=@var{user}
5711 @itemx -u @var{user}
5712 For containers, use the username @var{user} in place of the current
5713 user. The generated @file{/etc/passwd} entry within the container will
5714 contain the name @var{user}, the home directory will be
5715 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
5716 the UID and GID inside the container are 1000. @var{user}
5717 need not exist on the system.
5719 Additionally, any shared or exposed path (see @option{--share} and
5720 @option{--expose} respectively) whose target is within the current user's
5721 home directory will be remapped relative to @file{/home/USER}; this
5722 includes the automatic mapping of the current working directory.
5725 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
5727 guix environment --container --user=foo \
5728 --expose=$HOME/test \
5729 --expose=/tmp/target=$HOME/target
5732 While this will limit the leaking of user identity through home paths
5733 and each of the user fields, this is only one useful component of a
5734 broader privacy/anonymity solution---not one in and of itself.
5737 For containers, the default behavior is to share the current working
5738 directory with the isolated container and immediately change to that
5739 directory within the container. If this is undesirable,
5740 @option{--no-cwd} will cause the current working directory to @emph{not}
5741 be automatically shared and will change to the user's home directory
5742 within the container instead. See also @option{--user}.
5744 @item --expose=@var{source}[=@var{target}]
5745 @itemx --share=@var{source}[=@var{target}]
5746 For containers, @option{--expose} (resp. @option{--share}) exposes the
5747 file system @var{source} from the host system as the read-only
5748 (resp. writable) file system @var{target} within the container. If
5749 @var{target} is not specified, @var{source} is used as the target mount
5750 point in the container.
5752 The example below spawns a Guile REPL in a container in which the user's
5753 home directory is accessible read-only via the @file{/exchange}
5757 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
5762 @command{guix environment}
5763 also supports all of the common build options that @command{guix
5764 build} supports (@pxref{Common Build Options}) as well as package
5765 transformation options (@pxref{Package Transformation Options}).
5767 @node Invoking guix pack
5768 @section Invoking @command{guix pack}
5770 Occasionally you want to pass software to people who are not (yet!)
5771 lucky enough to be using Guix. You'd tell them to run @command{guix
5772 package -i @var{something}}, but that's not possible in this case. This
5773 is where @command{guix pack} comes in.
5776 If you are looking for ways to exchange binaries among machines that
5777 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
5778 publish}, and @ref{Invoking guix archive}.
5783 @cindex application bundle
5784 @cindex software bundle
5785 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
5786 @dfn{software bundle}: it creates a tarball or some other archive
5787 containing the binaries of the software you're interested in, and all
5788 its dependencies. The resulting archive can be used on any machine that
5789 does not have Guix, and people can run the exact same binaries as those
5790 you have with Guix. The pack itself is created in a bit-reproducible
5791 fashion, so anyone can verify that it really contains the build results
5792 that you pretend to be shipping.
5794 For example, to create a bundle containing Guile, Emacs, Geiser, and all
5795 their dependencies, you can run:
5798 $ guix pack guile emacs geiser
5800 /gnu/store/@dots{}-pack.tar.gz
5803 The result here is a tarball containing a @file{/gnu/store} directory
5804 with all the relevant packages. The resulting tarball contains a
5805 @dfn{profile} with the three packages of interest; the profile is the
5806 same as would be created by @command{guix package -i}. It is this
5807 mechanism that is used to create Guix's own standalone binary tarball
5808 (@pxref{Binary Installation}).
5810 Users of this pack would have to run
5811 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
5812 find inconvenient. To work around it, you can create, say, a
5813 @file{/opt/gnu/bin} symlink to the profile:
5816 guix pack -S /opt/gnu/bin=bin guile emacs geiser
5820 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
5822 @cindex relocatable binaries, with @command{guix pack}
5823 What if the recipient of your pack does not have root privileges on
5824 their machine, and thus cannot unpack it in the root file system? In
5825 that case, you will want to use the @option{--relocatable} option (see
5826 below). This option produces @dfn{relocatable binaries}, meaning they
5827 they can be placed anywhere in the file system hierarchy: in the example
5828 above, users can unpack your tarball in their home directory and
5829 directly run @file{./opt/gnu/bin/guile}.
5831 @cindex Docker, build an image with guix pack
5832 Alternatively, you can produce a pack in the Docker image format using
5833 the following command:
5836 guix pack -f docker -S /bin=bin guile guile-readline
5840 The result is a tarball that can be passed to the @command{docker load}
5841 command, followed by @code{docker run}:
5844 docker load < @var{file}
5845 docker run -ti guile-guile-readline /bin/guile
5849 where @var{file} is the image returned by @var{guix pack}, and
5850 @code{guile-guile-readline} is its ``image tag''. See the
5851 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
5852 documentation} for more information.
5854 @cindex Singularity, build an image with guix pack
5855 @cindex SquashFS, build an image with guix pack
5856 Yet another option is to produce a SquashFS image with the following
5860 guix pack -f squashfs bash guile emacs geiser
5864 The result is a SquashFS file system image that can either be mounted or
5865 directly be used as a file system container image with the
5866 @uref{https://www.sylabs.io/docs/, Singularity container execution
5867 environment}, using commands like @command{singularity shell} or
5868 @command{singularity exec}.
5870 Several command-line options allow you to customize your pack:
5873 @item --format=@var{format}
5874 @itemx -f @var{format}
5875 Produce a pack in the given @var{format}.
5877 The available formats are:
5881 This is the default format. It produces a tarball containing all the
5882 specified binaries and symlinks.
5885 This produces a tarball that follows the
5886 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
5887 Docker Image Specification}. The ``repository name'' as it appears in
5888 the output of the @command{docker images} command is computed from
5889 package names passed on the command line or in the manifest file.
5892 This produces a SquashFS image containing all the specified binaries and
5893 symlinks, as well as empty mount points for virtual file systems like
5897 Singularity @emph{requires} you to provide @file{/bin/sh} in the image.
5898 For that reason, @command{guix pack -f squashfs} always implies @code{-S
5899 /bin=bin}. Thus, your @command{guix pack} invocation must always start
5900 with something like:
5903 guix pack -f squashfs bash @dots{}
5906 If you forget the @code{bash} (or similar) package, @command{singularity
5907 run} and @command{singularity exec} will fail with an unhelpful ``no
5908 such file or directory'' message.
5912 @cindex relocatable binaries
5915 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
5916 anywhere in the file system hierarchy and run from there.
5918 When this option is passed once, the resulting binaries require support for
5919 @dfn{user namespaces} in the kernel Linux; when passed
5920 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
5921 PRoot support, can be thought of as the abbreviation of ``Really
5922 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to
5923 other techniques if user namespaces are unavailable, and essentially
5924 work anywhere---see below for the implications.
5926 For example, if you create a pack containing Bash with:
5929 guix pack -RR -S /mybin=bin bash
5933 ...@: you can copy that pack to a machine that lacks Guix, and from your
5934 home directory as a normal user, run:
5942 In that shell, if you type @code{ls /gnu/store}, you'll notice that
5943 @file{/gnu/store} shows up and contains all the dependencies of
5944 @code{bash}, even though the machine actually lacks @file{/gnu/store}
5945 altogether! That is probably the simplest way to deploy Guix-built
5946 software on a non-Guix machine.
5949 By default, relocatable binaries rely on the @dfn{user namespace} feature of
5950 the kernel Linux, which allows unprivileged users to mount or change root.
5951 Old versions of Linux did not support it, and some GNU/Linux distributions
5954 To produce relocatable binaries that work even in the absence of user
5955 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
5956 case, binaries will try user namespace support and fall back to another
5957 @dfn{execution engine} if user namespaces are not supported. The
5958 following execution engines are supported:
5962 Try user namespaces and fall back to PRoot if user namespaces are not
5963 supported (see below).
5966 Try user namespaces and fall back to Fakechroot if user namespaces are
5967 not supported (see below).
5970 Run the program through user namespaces and abort if they are not
5974 Run through PRoot. The @uref{https://proot-me.github.io/, PRoot} program
5975 provides the necessary
5976 support for file system virtualization. It achieves that by using the
5977 @code{ptrace} system call on the running program. This approach has the
5978 advantage to work without requiring special kernel support, but it incurs
5979 run-time overhead every time a system call is made.
5982 Run through Fakechroot. @uref{https://github.com/dex4er/fakechroot/,
5983 Fakechroot} virtualizes file system accesses by intercepting calls to C
5984 library functions such as @code{open}, @code{stat}, @code{exec}, and so
5985 on. Unlike PRoot, it incurs very little overhead. However, it does not
5986 always work: for example, some file system accesses made from within the
5987 C library are not intercepted, and file system accesses made @i{via}
5988 direct syscalls are not intercepted either, leading to erratic behavior.
5991 @vindex GUIX_EXECUTION_ENGINE
5992 When running a wrapped program, you can explicitly request one of the
5993 execution engines listed above by setting the
5994 @env{GUIX_EXECUTION_ENGINE} environment variable accordingly.
5997 @cindex entry point, for Docker images
5998 @item --entry-point=@var{command}
5999 Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
6000 format supports it---currently @code{docker} and @code{squashfs} (Singularity)
6001 support it. @var{command} must be relative to the profile contained in the
6004 The entry point specifies the command that tools like @code{docker run} or
6005 @code{singularity run} automatically start by default. For example, you can
6009 guix pack -f docker --entry-point=bin/guile guile
6012 The resulting pack can easily be loaded and @code{docker run} with no extra
6013 arguments will spawn @code{bin/guile}:
6016 docker load -i pack.tar.gz
6017 docker run @var{image-id}
6020 @item --expression=@var{expr}
6021 @itemx -e @var{expr}
6022 Consider the package @var{expr} evaluates to.
6024 This has the same purpose as the same-named option in @command{guix
6025 build} (@pxref{Additional Build Options, @option{--expression} in
6026 @command{guix build}}).
6028 @item --manifest=@var{file}
6029 @itemx -m @var{file}
6030 Use the packages contained in the manifest object returned by the Scheme
6031 code in @var{file}. This option can be repeated several times, in which
6032 case the manifests are concatenated.
6034 This has a similar purpose as the same-named option in @command{guix
6035 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
6036 same manifest files. It allows you to define a collection of packages
6037 once and use it both for creating profiles and for creating archives
6038 for use on machines that do not have Guix installed. Note that you can
6039 specify @emph{either} a manifest file @emph{or} a list of packages,
6042 @item --system=@var{system}
6043 @itemx -s @var{system}
6044 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
6045 the system type of the build host.
6047 @item --target=@var{triplet}
6048 @cindex cross-compilation
6049 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
6050 as @code{"aarch64-linux-gnu"} (@pxref{Specifying target triplets, GNU
6051 configuration triplets,, autoconf, Autoconf}).
6053 @item --compression=@var{tool}
6054 @itemx -C @var{tool}
6055 Compress the resulting tarball using @var{tool}---one of @code{gzip},
6056 @code{zstd}, @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no
6059 @item --symlink=@var{spec}
6060 @itemx -S @var{spec}
6061 Add the symlinks specified by @var{spec} to the pack. This option can
6062 appear several times.
6064 @var{spec} has the form @code{@var{source}=@var{target}}, where
6065 @var{source} is the symlink that will be created and @var{target} is the
6068 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
6069 symlink pointing to the @file{bin} sub-directory of the profile.
6071 @item --save-provenance
6072 Save provenance information for the packages passed on the command line.
6073 Provenance information includes the URL and commit of the channels in use
6076 Provenance information is saved in the
6077 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
6078 usual package metadata---the name and version of each package, their
6079 propagated inputs, and so on. It is useful information to the recipient of
6080 the pack, who then knows how the pack was (supposedly) obtained.
6082 This option is not enabled by default because, like timestamps, provenance
6083 information contributes nothing to the build process. In other words, there
6084 is an infinity of channel URLs and commit IDs that can lead to the same pack.
6085 Recording such ``silent'' metadata in the output thus potentially breaks the
6086 source-to-binary bitwise reproducibility property.
6088 @item --root=@var{file}
6089 @itemx -r @var{file}
6090 @cindex garbage collector root, for packs
6091 Make @var{file} a symlink to the resulting pack, and register it as a garbage
6094 @item --localstatedir
6095 @itemx --profile-name=@var{name}
6096 Include the ``local state directory'', @file{/var/guix}, in the resulting
6097 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
6098 profile---by default @var{name} is @code{guix-profile}, which corresponds to
6099 @file{~root/.guix-profile}.
6101 @file{/var/guix} contains the store database (@pxref{The Store}) as well
6102 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
6103 the pack means that the store is ``complete'' and manageable by Guix;
6104 not providing it pack means that the store is ``dead'': items cannot be
6105 added to it or removed from it after extraction of the pack.
6107 One use case for this is the Guix self-contained binary tarball
6108 (@pxref{Binary Installation}).
6112 Print the name of the derivation that builds the pack.
6115 Use the bootstrap binaries to build the pack. This option is only
6116 useful to Guix developers.
6119 In addition, @command{guix pack} supports all the common build options
6120 (@pxref{Common Build Options}) and all the package transformation
6121 options (@pxref{Package Transformation Options}).
6124 @node The GCC toolchain
6125 @section The GCC toolchain
6129 @cindex linker wrapper
6130 @cindex toolchain, for C development
6131 @cindex toolchain, for Fortran development
6133 If you need a complete toolchain for compiling and linking C or C++
6134 source code, use the @code{gcc-toolchain} package. This package
6135 provides a complete GCC toolchain for C/C++ development, including GCC
6136 itself, the GNU C Library (headers and binaries, plus debugging symbols
6137 in the @code{debug} output), Binutils, and a linker wrapper.
6139 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
6140 passed to the linker, add corresponding @code{-rpath} arguments, and
6141 invoke the actual linker with this new set of arguments. You can instruct the
6142 wrapper to refuse to link against libraries not in the store by setting the
6143 @env{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
6145 The package @code{gfortran-toolchain} provides a complete GCC toolchain
6146 for Fortran development. For other languages, please use
6147 @samp{guix search gcc toolchain} (@pxref{guix-search,, Invoking guix package}).
6150 @node Invoking guix git authenticate
6151 @section Invoking @command{guix git authenticate}
6153 The @command{guix git authenticate} command authenticates a Git checkout
6154 following the same rule as for channels (@pxref{channel-authentication,
6155 channel authentication}). That is, starting from a given commit, it
6156 ensures that all subsequent commits are signed by an OpenPGP key whose
6157 fingerprint appears in the @file{.guix-authorizations} file of its
6160 You will find this command useful if you maintain a channel. But in
6161 fact, this authentication mechanism is useful in a broader context, so
6162 you might want to use it for Git repositories that have nothing to do
6165 The general syntax is:
6168 guix git authenticate @var{commit} @var{signer} [@var{options}@dots{}]
6171 By default, this command authenticates the Git checkout in the current
6172 directory; it outputs nothing and exits with exit code zero on success
6173 and non-zero on failure. @var{commit} above denotes the first commit
6174 where authentication takes place, and @var{signer} is the OpenPGP
6175 fingerprint of public key used to sign @var{commit}. Together, they
6176 form a ``channel introduction'' (@pxref{channel-authentication, channel
6177 introduction}). The options below allow you to fine-tune the process.
6180 @item --repository=@var{directory}
6181 @itemx -r @var{directory}
6182 Open the Git repository in @var{directory} instead of the current
6185 @item --keyring=@var{reference}
6186 @itemx -k @var{reference}
6187 Load OpenPGP keyring from @var{reference}, the reference of a branch
6188 such as @code{origin/keyring} or @code{my-keyring}. The branch must
6189 contain OpenPGP public keys in @file{.key} files, either in binary form
6190 or ``ASCII-armored''. By default the keyring is loaded from the branch
6191 named @code{keyring}.
6194 Display commit signing statistics upon completion.
6196 @item --cache-key=@var{key}
6197 Previously-authenticated commits are cached in a file under
6198 @file{~/.cache/guix/authentication}. This option forces the cache to be
6199 stored in file @var{key} in that directory.
6201 @item --historical-authorizations=@var{file}
6202 By default, any commit whose parent commit(s) lack the
6203 @file{.guix-authorizations} file is considered inauthentic. In
6204 contrast, this option considers the authorizations in @var{file} for any
6205 commit that lacks @file{.guix-authorizations}. The format of @var{file}
6206 is the same as that of @file{.guix-authorizations}
6207 (@pxref{channel-authorizations, @file{.guix-authorizations} format}).
6211 @c *********************************************************************
6212 @node Programming Interface
6213 @chapter Programming Interface
6215 GNU Guix provides several Scheme programming interfaces (APIs) to
6216 define, build, and query packages. The first interface allows users to
6217 write high-level package definitions. These definitions refer to
6218 familiar packaging concepts, such as the name and version of a package,
6219 its build system, and its dependencies. These definitions can then be
6220 turned into concrete build actions.
6222 Build actions are performed by the Guix daemon, on behalf of users. In a
6223 standard setup, the daemon has write access to the store---the
6224 @file{/gnu/store} directory---whereas users do not. The recommended
6225 setup also has the daemon perform builds in chroots, under specific
6226 build users, to minimize interference with the rest of the system.
6229 Lower-level APIs are available to interact with the daemon and the
6230 store. To instruct the daemon to perform a build action, users actually
6231 provide it with a @dfn{derivation}. A derivation is a low-level
6232 representation of the build actions to be taken, and the environment in
6233 which they should occur---derivations are to package definitions what
6234 assembly is to C programs. The term ``derivation'' comes from the fact
6235 that build results @emph{derive} from them.
6237 This chapter describes all these APIs in turn, starting from high-level
6238 package definitions.
6241 * Package Modules:: Packages from the programmer's viewpoint.
6242 * Defining Packages:: Defining new packages.
6243 * Defining Package Variants:: Customizing packages.
6244 * Build Systems:: Specifying how packages are built.
6245 * Build Phases:: Phases of the build process of a package.
6246 * Build Utilities:: Helpers for your package definitions and more.
6247 * The Store:: Manipulating the package store.
6248 * Derivations:: Low-level interface to package derivations.
6249 * The Store Monad:: Purely functional interface to the store.
6250 * G-Expressions:: Manipulating build expressions.
6251 * Invoking guix repl:: Programming Guix in Guile
6254 @node Package Modules
6255 @section Package Modules
6257 From a programming viewpoint, the package definitions of the
6258 GNU distribution are provided by Guile modules in the @code{(gnu packages
6259 @dots{})} name space@footnote{Note that packages under the @code{(gnu
6260 packages @dots{})} module name space are not necessarily ``GNU
6261 packages''. This module naming scheme follows the usual Guile module
6262 naming convention: @code{gnu} means that these modules are distributed
6263 as part of the GNU system, and @code{packages} identifies modules that
6264 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
6265 Reference Manual}). For instance, the @code{(gnu packages emacs)}
6266 module exports a variable named @code{emacs}, which is bound to a
6267 @code{<package>} object (@pxref{Defining Packages}).
6269 The @code{(gnu packages @dots{})} module name space is
6270 automatically scanned for packages by the command-line tools. For
6271 instance, when running @code{guix install emacs}, all the @code{(gnu
6272 packages @dots{})} modules are scanned until one that exports a package
6273 object whose name is @code{emacs} is found. This package search
6274 facility is implemented in the @code{(gnu packages)} module.
6276 @cindex customization, of packages
6277 @cindex package module search path
6278 Users can store package definitions in modules with different
6279 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
6280 name and module name must match. For instance, the @code{(my-packages
6281 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
6282 relative to the load path specified with @option{--load-path} or
6283 @env{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
6284 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
6285 these package definitions visible to the user interfaces:
6289 By adding the directory containing your package modules to the search path
6290 with the @code{-L} flag of @command{guix package} and other commands
6291 (@pxref{Common Build Options}), or by setting the @env{GUIX_PACKAGE_PATH}
6292 environment variable described below.
6295 By defining a @dfn{channel} and configuring @command{guix pull} so that it
6296 pulls from it. A channel is essentially a Git repository containing package
6297 modules. @xref{Channels}, for more information on how to define and use
6301 @env{GUIX_PACKAGE_PATH} works similarly to other search path variables:
6303 @defvr {Environment Variable} GUIX_PACKAGE_PATH
6304 This is a colon-separated list of directories to search for additional
6305 package modules. Directories listed in this variable take precedence
6306 over the own modules of the distribution.
6309 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
6310 each package is built based solely on other packages in the
6311 distribution. The root of this dependency graph is a small set of
6312 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
6313 bootstrap)} module. For more information on bootstrapping,
6314 @pxref{Bootstrapping}.
6316 @node Defining Packages
6317 @section Defining Packages
6319 The high-level interface to package definitions is implemented in the
6320 @code{(guix packages)} and @code{(guix build-system)} modules. As an
6321 example, the package definition, or @dfn{recipe}, for the GNU Hello
6322 package looks like this:
6325 (define-module (gnu packages hello)
6326 #:use-module (guix packages)
6327 #:use-module (guix download)
6328 #:use-module (guix build-system gnu)
6329 #:use-module (guix licenses)
6330 #:use-module (gnu packages gawk))
6332 (define-public hello
6338 (uri (string-append "mirror://gnu/hello/hello-" version
6342 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
6343 (build-system gnu-build-system)
6344 (arguments '(#:configure-flags '("--enable-silent-rules")))
6345 (inputs `(("gawk" ,gawk)))
6346 (synopsis "Hello, GNU world: An example GNU package")
6347 (description "Guess what GNU Hello prints!")
6348 (home-page "https://www.gnu.org/software/hello/")
6353 Without being a Scheme expert, the reader may have guessed the meaning
6354 of the various fields here. This expression binds the variable
6355 @code{hello} to a @code{<package>} object, which is essentially a record
6356 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
6357 This package object can be inspected using procedures found in the
6358 @code{(guix packages)} module; for instance, @code{(package-name hello)}
6359 returns---surprise!---@code{"hello"}.
6361 With luck, you may be able to import part or all of the definition of
6362 the package you are interested in from another repository, using the
6363 @code{guix import} command (@pxref{Invoking guix import}).
6365 In the example above, @code{hello} is defined in a module of its own,
6366 @code{(gnu packages hello)}. Technically, this is not strictly
6367 necessary, but it is convenient to do so: all the packages defined in
6368 modules under @code{(gnu packages @dots{})} are automatically known to
6369 the command-line tools (@pxref{Package Modules}).
6371 There are a few points worth noting in the above package definition:
6375 The @code{source} field of the package is an @code{<origin>} object
6376 (@pxref{origin Reference}, for the complete reference).
6377 Here, the @code{url-fetch} method from @code{(guix download)} is used,
6378 meaning that the source is a file to be downloaded over FTP or HTTP.
6380 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
6381 the GNU mirrors defined in @code{(guix download)}.
6383 The @code{sha256} field specifies the expected SHA256 hash of the file
6384 being downloaded. It is mandatory, and allows Guix to check the
6385 integrity of the file. The @code{(base32 @dots{})} form introduces the
6386 base32 representation of the hash. You can obtain this information with
6387 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
6388 hash} (@pxref{Invoking guix hash}).
6391 When needed, the @code{origin} form can also have a @code{patches} field
6392 listing patches to be applied, and a @code{snippet} field giving a
6393 Scheme expression to modify the source code.
6396 @cindex GNU Build System
6397 The @code{build-system} field specifies the procedure to build the
6398 package (@pxref{Build Systems}). Here, @code{gnu-build-system}
6399 represents the familiar GNU Build System, where packages may be
6400 configured, built, and installed with the usual @code{./configure &&
6401 make && make check && make install} command sequence.
6403 When you start packaging non-trivial software, you may need tools to
6404 manipulate those build phases, manipulate files, and so on. @xref{Build
6405 Utilities}, for more on this.
6408 The @code{arguments} field specifies options for the build system
6409 (@pxref{Build Systems}). Here it is interpreted by
6410 @code{gnu-build-system} as a request run @file{configure} with the
6411 @option{--enable-silent-rules} flag.
6417 What about these quote (@code{'}) characters? They are Scheme syntax to
6418 introduce a literal list; @code{'} is synonymous with @code{quote}.
6419 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
6420 for details. Here the value of the @code{arguments} field is a list of
6421 arguments passed to the build system down the road, as with @code{apply}
6422 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
6425 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
6426 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
6427 @code{#:configure-flags} is a keyword used to pass a keyword argument
6428 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
6432 The @code{inputs} field specifies inputs to the build process---i.e.,
6433 build-time or run-time dependencies of the package. Here, we define an
6434 input called @code{"gawk"} whose value is that of the @code{gawk}
6435 variable; @code{gawk} is itself bound to a @code{<package>} object.
6437 @cindex backquote (quasiquote)
6440 @cindex comma (unquote)
6444 @findex unquote-splicing
6445 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
6446 us to introduce a literal list in the @code{inputs} field, while
6447 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
6448 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
6451 Note that GCC, Coreutils, Bash, and other essential tools do not need to
6452 be specified as inputs here. Instead, @code{gnu-build-system} takes care
6453 of ensuring that they are present (@pxref{Build Systems}).
6455 However, any other dependencies need to be specified in the
6456 @code{inputs} field. Any dependency not specified here will simply be
6457 unavailable to the build process, possibly leading to a build failure.
6460 @xref{package Reference}, for a full description of possible fields.
6462 Once a package definition is in place, the
6463 package may actually be built using the @code{guix build} command-line
6464 tool (@pxref{Invoking guix build}), troubleshooting any build failures
6465 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
6466 package definition using the @command{guix edit} command
6467 (@pxref{Invoking guix edit}).
6468 @xref{Packaging Guidelines}, for
6469 more information on how to test package definitions, and
6470 @ref{Invoking guix lint}, for information on how to check a definition
6471 for style conformance.
6472 @vindex GUIX_PACKAGE_PATH
6473 Lastly, @pxref{Channels}, for information
6474 on how to extend the distribution by adding your own package definitions
6477 Finally, updating the package definition to a new upstream version
6478 can be partly automated by the @command{guix refresh} command
6479 (@pxref{Invoking guix refresh}).
6481 Behind the scenes, a derivation corresponding to the @code{<package>}
6482 object is first computed by the @code{package-derivation} procedure.
6483 That derivation is stored in a @file{.drv} file under @file{/gnu/store}.
6484 The build actions it prescribes may then be realized by using the
6485 @code{build-derivations} procedure (@pxref{The Store}).
6487 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
6488 Return the @code{<derivation>} object of @var{package} for @var{system}
6489 (@pxref{Derivations}).
6491 @var{package} must be a valid @code{<package>} object, and @var{system}
6492 must be a string denoting the target system type---e.g.,
6493 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
6494 must be a connection to the daemon, which operates on the store
6495 (@pxref{The Store}).
6499 @cindex cross-compilation
6500 Similarly, it is possible to compute a derivation that cross-builds a
6501 package for some other system:
6503 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
6504 @var{package} @var{target} [@var{system}]
6505 Return the @code{<derivation>} object of @var{package} cross-built from
6506 @var{system} to @var{target}.
6508 @var{target} must be a valid GNU triplet denoting the target hardware
6509 and operating system, such as @code{"aarch64-linux-gnu"}
6510 (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
6513 Once you have package definitions, you can easily define @emph{variants}
6514 of those packages. @xref{Defining Package Variants}, for more on that.
6517 * package Reference:: The package data type.
6518 * origin Reference:: The origin data type.
6522 @node package Reference
6523 @subsection @code{package} Reference
6525 This section summarizes all the options available in @code{package}
6526 declarations (@pxref{Defining Packages}).
6528 @deftp {Data Type} package
6529 This is the data type representing a package recipe.
6533 The name of the package, as a string.
6535 @item @code{version}
6536 The version of the package, as a string.
6539 An object telling how the source code for the package should be
6540 acquired. Most of the time, this is an @code{origin} object, which
6541 denotes a file fetched from the Internet (@pxref{origin Reference}). It
6542 can also be any other ``file-like'' object such as a @code{local-file},
6543 which denotes a file from the local file system (@pxref{G-Expressions,
6544 @code{local-file}}).
6546 @item @code{build-system}
6547 The build system that should be used to build the package (@pxref{Build
6550 @item @code{arguments} (default: @code{'()})
6551 The arguments that should be passed to the build system. This is a
6552 list, typically containing sequential keyword-value pairs.
6554 @item @code{inputs} (default: @code{'()})
6555 @itemx @code{native-inputs} (default: @code{'()})
6556 @itemx @code{propagated-inputs} (default: @code{'()})
6557 @cindex inputs, of packages
6558 These fields list dependencies of the package. Each one is a list of
6559 tuples, where each tuple has a label for the input (a string) as its
6560 first element, a package, origin, or derivation as its second element,
6561 and optionally the name of the output thereof that should be used, which
6562 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
6563 more on package outputs). For example, the list below specifies three
6567 `(("libffi" ,libffi)
6568 ("libunistring" ,libunistring)
6569 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
6572 @cindex cross compilation, package dependencies
6573 The distinction between @code{native-inputs} and @code{inputs} is
6574 necessary when considering cross-compilation. When cross-compiling,
6575 dependencies listed in @code{inputs} are built for the @emph{target}
6576 architecture; conversely, dependencies listed in @code{native-inputs}
6577 are built for the architecture of the @emph{build} machine.
6579 @code{native-inputs} is typically used to list tools needed at
6580 build time, but not at run time, such as Autoconf, Automake, pkg-config,
6581 Gettext, or Bison. @command{guix lint} can report likely mistakes in
6582 this area (@pxref{Invoking guix lint}).
6584 @anchor{package-propagated-inputs}
6585 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
6586 specified packages will be automatically installed to profiles
6587 (@pxref{Features, the role of profiles in Guix}) alongside the package
6588 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
6589 package}}, for information on how @command{guix package} deals with
6592 For example this is necessary when packaging a C/C++ library that needs
6593 headers of another library to compile, or when a pkg-config file refers
6594 to another one @i{via} its @code{Requires} field.
6596 Another example where @code{propagated-inputs} is useful is for languages
6597 that lack a facility to record the run-time search path akin to the
6598 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
6599 more. When packaging libraries written in those languages, ensure they
6600 can find library code they depend on at run time by listing run-time
6601 dependencies in @code{propagated-inputs} rather than @code{inputs}.
6603 @item @code{outputs} (default: @code{'("out")})
6604 The list of output names of the package. @xref{Packages with Multiple
6605 Outputs}, for typical uses of additional outputs.
6607 @item @code{native-search-paths} (default: @code{'()})
6608 @itemx @code{search-paths} (default: @code{'()})
6609 A list of @code{search-path-specification} objects describing
6610 search-path environment variables honored by the package.
6612 @item @code{replacement} (default: @code{#f})
6613 This must be either @code{#f} or a package object that will be used as a
6614 @dfn{replacement} for this package. @xref{Security Updates, grafts},
6617 @item @code{synopsis}
6618 A one-line description of the package.
6620 @item @code{description}
6621 A more elaborate description of the package.
6623 @item @code{license}
6624 @cindex license, of packages
6625 The license of the package; a value from @code{(guix licenses)},
6626 or a list of such values.
6628 @item @code{home-page}
6629 The URL to the home-page of the package, as a string.
6631 @item @code{supported-systems} (default: @code{%supported-systems})
6632 The list of systems supported by the package, as strings of the form
6633 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
6635 @item @code{location} (default: source location of the @code{package} form)
6636 The source location of the package. It is useful to override this when
6637 inheriting from another package, in which case this field is not
6638 automatically corrected.
6642 @deffn {Scheme Syntax} this-package
6643 When used in the @emph{lexical scope} of a package field definition, this
6644 identifier resolves to the package being defined.
6646 The example below shows how to add a package as a native input of itself when
6654 ;; When cross-compiled, Guile, for example, depends on
6655 ;; a native version of itself. Add it here.
6656 (native-inputs (if (%current-target-system)
6657 `(("self" ,this-package))
6661 It is an error to refer to @code{this-package} outside a package definition.
6664 Because packages are regular Scheme objects that capture a complete
6665 dependency graph and associated build procedures, it is often useful to
6666 write procedures that take a package and return a modified version
6667 thereof according to some parameters. Below are a few examples.
6669 @cindex tool chain, choosing a package's tool chain
6670 @deffn {Scheme Procedure} package-with-c-toolchain @var{package} @var{toolchain}
6671 Return a variant of @var{package} that uses @var{toolchain} instead of
6672 the default GNU C/C++ toolchain. @var{toolchain} must be a list of
6673 inputs (label/package tuples) providing equivalent functionality, such
6674 as the @code{gcc-toolchain} package.
6676 The example below returns a variant of the @code{hello} package built
6677 with GCC@tie{}10.x and the rest of the GNU tool chain (Binutils and the
6678 GNU C Library) instead of the default tool chain:
6681 (let ((toolchain (specification->package "gcc-toolchain@@10")))
6682 (package-with-c-toolchain hello `(("toolchain" ,toolchain))))
6685 The build tool chain is part of the @dfn{implicit inputs} of
6686 packages---it's usually not listed as part of the various ``inputs''
6687 fields and is instead pulled in by the build system. Consequently, this
6688 procedure works by changing the build system of @var{package} so that it
6689 pulls in @var{toolchain} instead of the defaults. @ref{Build Systems},
6690 for more on build systems.
6693 @node origin Reference
6694 @subsection @code{origin} Reference
6696 This section documents @dfn{origins}. An @code{origin} declaration
6697 specifies data that must be ``produced''---downloaded, usually---and
6698 whose content hash is known in advance. Origins are primarily used to
6699 represent the source code of packages (@pxref{Defining Packages}). For
6700 that reason, the @code{origin} form allows you to declare patches to
6701 apply to the original source code as well as code snippets to modify it.
6703 @deftp {Data Type} origin
6704 This is the data type representing a source code origin.
6708 An object containing the URI of the source. The object type depends on
6709 the @code{method} (see below). For example, when using the
6710 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
6711 values are: a URL represented as a string, or a list thereof.
6713 @cindex fixed-output derivations, for download
6715 A monadic procedure that handles the given URI. The procedure must
6716 accept at least three arguments: the value of the @code{uri} field and
6717 the hash algorithm and hash value specified by the @code{hash} field.
6718 It must return a store item or a derivation in the store monad
6719 (@pxref{The Store Monad}); most methods return a fixed-output derivation
6720 (@pxref{Derivations}).
6722 Commonly used methods include @code{url-fetch}, which fetches data from
6723 a URL, and @code{git-fetch}, which fetches data from a Git repository
6727 A bytevector containing the SHA-256 hash of the source. This is
6728 equivalent to providing a @code{content-hash} SHA256 object in the
6729 @code{hash} field described below.
6732 The @code{content-hash} object of the source---see below for how to use
6733 @code{content-hash}.
6735 You can obtain this information using @code{guix download}
6736 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
6739 @item @code{file-name} (default: @code{#f})
6740 The file name under which the source code should be saved. When this is
6741 @code{#f}, a sensible default value will be used in most cases. In case
6742 the source is fetched from a URL, the file name from the URL will be
6743 used. For version control checkouts, it is recommended to provide the
6744 file name explicitly because the default is not very descriptive.
6746 @item @code{patches} (default: @code{'()})
6747 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
6748 file-like objects}) pointing to patches to be applied to the source.
6750 This list of patches must be unconditional. In particular, it cannot
6751 depend on the value of @code{%current-system} or
6752 @code{%current-target-system}.
6754 @item @code{snippet} (default: @code{#f})
6755 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
6756 in the source directory. This is a convenient way to modify the source,
6757 sometimes more convenient than a patch.
6759 @item @code{patch-flags} (default: @code{'("-p1")})
6760 A list of command-line flags that should be passed to the @code{patch}
6763 @item @code{patch-inputs} (default: @code{#f})
6764 Input packages or derivations to the patching process. When this is
6765 @code{#f}, the usual set of inputs necessary for patching are provided,
6766 such as GNU@tie{}Patch.
6768 @item @code{modules} (default: @code{'()})
6769 A list of Guile modules that should be loaded during the patching
6770 process and while running the code in the @code{snippet} field.
6772 @item @code{patch-guile} (default: @code{#f})
6773 The Guile package that should be used in the patching process. When
6774 this is @code{#f}, a sensible default is used.
6778 @deftp {Data Type} content-hash @var{value} [@var{algorithm}]
6779 Construct a content hash object for the given @var{algorithm}, and with
6780 @var{value} as its hash value. When @var{algorithm} is omitted, assume
6781 it is @code{sha256}.
6783 @var{value} can be a literal string, in which case it is base32-decoded,
6784 or it can be a bytevector.
6786 The following forms are all equivalent:
6789 (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj")
6790 (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"
6792 (content-hash (base32
6793 "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"))
6794 (content-hash (base64 "kkb+RPaP7uyMZmu4eXPVkM4BN8yhRd8BTHLslb6f/Rc=")
6798 Technically, @code{content-hash} is currently implemented as a macro.
6799 It performs sanity checks at macro-expansion time, when possible, such
6800 as ensuring that @var{value} has the right size for @var{algorithm}.
6803 As we have seen above, how exactly the data an origin refers to is
6804 retrieved is determined by its @code{method} field. The @code{(guix
6805 download)} module provides the most common method, @code{url-fetch},
6808 @deffn {Scheme Procedure} url-fetch @var{url} @var{hash-algo} @var{hash} @
6809 [name] [#:executable? #f]
6810 Return a fixed-output derivation that fetches data from @var{url} (a
6811 string, or a list of strings denoting alternate URLs), which is expected
6812 to have hash @var{hash} of type @var{hash-algo} (a symbol). By default,
6813 the file name is the base name of URL; optionally, @var{name} can
6814 specify a different file name. When @var{executable?} is true, make the
6815 downloaded file executable.
6817 When one of the URL starts with @code{mirror://}, then its host part is
6818 interpreted as the name of a mirror scheme, taken from @file{%mirror-file}.
6820 Alternatively, when URL starts with @code{file://}, return the
6821 corresponding file name in the store.
6824 Likewise, the @code{(guix git-download)} module defines the
6825 @code{git-fetch} origin method, which fetches data from a Git version
6826 control repository, and the @code{git-reference} data type to describe
6827 the repository and revision to fetch.
6829 @deffn {Scheme Procedure} git-fetch @var{ref} @var{hash-algo} @var{hash}
6830 Return a fixed-output derivation that fetches @var{ref}, a
6831 @code{<git-reference>} object. The output is expected to have recursive
6832 hash @var{hash} of type @var{hash-algo} (a symbol). Use @var{name} as
6833 the file name, or a generic name if @code{#f}.
6836 @deftp {Data Type} git-reference
6837 This data type represents a Git reference for @code{git-fetch} to
6842 The URL of the Git repository to clone.
6845 This string denotes either the commit to fetch (a hexadecimal string,
6846 either the full SHA1 commit or a ``short'' commit string; the latter is
6847 not recommended) or the tag to fetch.
6849 @item @code{recursive?} (default: @code{#f})
6850 This Boolean indicates whether to recursively fetch Git sub-modules.
6853 The example below denotes the @code{v2.10} tag of the GNU@tie{}Hello
6858 (url "https://git.savannah.gnu.org/git/hello.git")
6862 This is equivalent to the reference below, which explicitly names the
6867 (url "https://git.savannah.gnu.org/git/hello.git")
6868 (commit "dc7dc56a00e48fe6f231a58f6537139fe2908fb9"))
6872 For Mercurial repositories, the module @code{(guix hg-download)} defines
6873 the @code{hg-fetch} origin method and @code{hg-reference} data type for
6874 support of the Mercurial version control system.
6876 @deffn {Scheme Procedure} hg-fetch @var{ref} @var{hash-algo} @var{hash} @
6878 Return a fixed-output derivation that fetches @var{ref}, a
6879 @code{<hg-reference>} object. The output is expected to have recursive
6880 hash @var{hash} of type @var{hash-algo} (a symbol). Use @var{name} as
6881 the file name, or a generic name if @code{#false}.
6884 @node Defining Package Variants
6885 @section Defining Package Variants
6887 @cindex customizing packages
6888 @cindex variants, of packages
6889 One of the nice things with Guix is that, given a package definition,
6890 you can easily @emph{derive} variants of that package---for a different
6891 upstream version, with different dependencies, different compilation
6892 options, and so on. Some of these custom packages can be defined
6893 straight from the command line (@pxref{Package Transformation Options}).
6894 This section describes how to define package variants in code. This can
6895 be useful in ``manifests'' (@pxref{profile-manifest,
6896 @option{--manifest}}) and in your own package collection
6897 (@pxref{Creating a Channel}), among others!
6899 @cindex inherit, for package definitions
6900 As discussed earlier, packages are first-class objects in the Scheme
6901 language. The @code{(guix packages)} module provides the @code{package}
6902 construct to define new package objects (@pxref{package Reference}).
6903 The easiest way to define a package variant is using the @code{inherit}
6904 keyword together with @code{package}. This allows you to inherit from a
6905 package definition while overriding the fields you want.
6907 For example, given the @code{hello} variable, which contains a
6908 definition for the current version of GNU@tie{}Hello, here's how you
6909 would define a variant for version 2.2 (released in 2006, it's
6913 (use-modules (gnu packages base)) ;for 'hello'
6921 (uri (string-append "mirror://gnu/hello/hello-" version
6925 "0lappv4slgb5spyqbh6yl5r013zv72yqg2pcl30mginf3wdqd8k9"))))))
6928 The example above corresponds to what the @option{--with-source} package
6929 transformation option does. Essentially @code{hello-2.2} preserves all
6930 the fields of @code{hello}, except @code{version} and @code{source},
6931 which it overrides. Note that the original @code{hello} variable is
6932 still there, in the @code{(gnu packages base)} module, unchanged. When
6933 you define a custom package like this, you are really @emph{adding} a
6934 new package definition; the original one remains available.
6936 You can just as well define variants with a different set of
6937 dependencies than the original package. For example, the default
6938 @code{gdb} package depends on @code{guile}, but since that is an
6939 optional dependency, you can define a variant that removes that
6943 (use-modules (gnu packages gdb) ;for 'gdb'
6944 (srfi srfi-1)) ;for 'alist-delete'
6946 (define gdb-sans-guile
6949 (inputs (alist-delete "guile"
6950 (package-inputs gdb)))))
6953 The @code{alist-delete} call above removes the tuple from the
6954 @code{inputs} field that has @code{"guile"} as its first element
6955 (@pxref{SRFI-1 Association Lists,,, guile, GNU Guile Reference
6958 In some cases, you may find it useful to write functions
6959 (``procedures'', in Scheme parlance) that return a package based on some
6960 parameters. For example, consider the @code{luasocket} library for the
6961 Lua programming language. We want to create @code{luasocket} packages
6962 for major versions of Lua. One way to do that is to define a procedure
6963 that takes a Lua package and returns a @code{luasocket} package that
6967 (define (make-lua-socket name lua)
6968 ;; Return a luasocket package built with LUA.
6972 ;; several fields omitted
6975 (synopsis "Socket library for Lua")))
6977 (define-public lua5.1-socket
6978 (make-lua-socket "lua5.1-socket" lua-5.1))
6980 (define-public lua5.2-socket
6981 (make-lua-socket "lua5.2-socket" lua-5.2))
6984 Here we have defined packages @code{lua5.1-socket} and
6985 @code{lua5.2-socket} by calling @code{make-lua-socket} with different
6986 arguments. @xref{Procedures,,, guile, GNU Guile Reference Manual}, for
6987 more info on procedures. Having top-level public definitions for these
6988 two packages means that they can be referred to from the command line
6989 (@pxref{Package Modules}).
6991 @cindex package transformations
6992 These are pretty simple package variants. As a convenience, the
6993 @code{(guix transformations)} module provides a high-level interface
6994 that directly maps to the more sophisticated package transformation
6995 options (@pxref{Package Transformation Options}):
6997 @deffn {Scheme Procedure} options->transformation @var{opts}
6998 Return a procedure that, when passed an object to build (package,
6999 derivation, etc.), applies the transformations specified by @var{opts} and returns
7000 the resulting objects. @var{opts} must be a list of symbol/string pairs such as:
7003 ((with-branch . "guile-gcrypt=master")
7004 (without-tests . "libgcrypt"))
7007 Each symbol names a transformation and the corresponding string is an argument
7008 to that transformation.
7011 For instance, a manifest equivalent to this command:
7015 --with-branch=guile-gcrypt=master \
7016 --with-debug-info=zlib
7020 ... would look like this:
7023 (use-modules (guix transformations))
7026 ;; The package transformation procedure.
7027 (options->transformation
7028 '((with-branch . "guile-gcrypt=master")
7029 (with-debug-info . "zlib"))))
7032 (list (transform (specification->package "guix"))))
7035 @cindex input rewriting
7036 @cindex dependency graph rewriting
7037 The @code{options->transformation} procedure is convenient, but it's
7038 perhaps also not as flexible as you may like. How is it implemented?
7039 The astute reader probably noticed that most package transformation
7040 options go beyond the superficial changes shown in the first examples of
7041 this section: they involve @dfn{input rewriting}, whereby the dependency
7042 graph of a package is rewritten by replacing specific inputs by others.
7044 Dependency graph rewriting, for the purposes of swapping packages in the
7045 graph, is what the @code{package-input-rewriting} procedure in
7046 @code{(guix packages)} implements.
7048 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
7049 [@var{rewrite-name}] [#:deep? #t]
7050 Return a procedure that, when passed a package, replaces its direct and
7051 indirect dependencies, including implicit inputs when @var{deep?} is
7052 true, according to @var{replacements}. @var{replacements} is a list of
7053 package pairs; the first element of each pair is the package to replace,
7054 and the second one is the replacement.
7056 Optionally, @var{rewrite-name} is a one-argument procedure that takes
7057 the name of a package and returns its new name after rewrite.
7061 Consider this example:
7064 (define libressl-instead-of-openssl
7065 ;; This is a procedure to replace OPENSSL by LIBRESSL,
7067 (package-input-rewriting `((,openssl . ,libressl))))
7069 (define git-with-libressl
7070 (libressl-instead-of-openssl git))
7074 Here we first define a rewriting procedure that replaces @var{openssl}
7075 with @var{libressl}. Then we use it to define a @dfn{variant} of the
7076 @var{git} package that uses @var{libressl} instead of @var{openssl}.
7077 This is exactly what the @option{--with-input} command-line option does
7078 (@pxref{Package Transformation Options, @option{--with-input}}).
7080 The following variant of @code{package-input-rewriting} can match packages to
7081 be replaced by name rather than by identity.
7083 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements} [#:deep? #t]
7084 Return a procedure that, given a package, applies the given
7085 @var{replacements} to all the package graph, including implicit inputs
7086 unless @var{deep?} is false. @var{replacements} is a list of
7087 spec/procedures pair; each spec is a package specification such as
7088 @code{"gcc"} or @code{"guile@@2"}, and each procedure takes a matching
7089 package and returns a replacement for that package.
7092 The example above could be rewritten this way:
7095 (define libressl-instead-of-openssl
7096 ;; Replace all the packages called "openssl" with LibreSSL.
7097 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
7100 The key difference here is that, this time, packages are matched by spec and
7101 not by identity. In other words, any package in the graph that is called
7102 @code{openssl} will be replaced.
7104 A more generic procedure to rewrite a package dependency graph is
7105 @code{package-mapping}: it supports arbitrary changes to nodes in the
7108 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}] [#:deep? #f]
7109 Return a procedure that, given a package, applies @var{proc} to all the packages
7110 depended on and returns the resulting package. The procedure stops recursion
7111 when @var{cut?} returns true for a given package. When @var{deep?} is true, @var{proc} is
7112 applied to implicit inputs as well.
7117 @section Build Systems
7119 @cindex build system
7120 Each package definition specifies a @dfn{build system} and arguments for
7121 that build system (@pxref{Defining Packages}). This @code{build-system}
7122 field represents the build procedure of the package, as well as implicit
7123 dependencies of that build procedure.
7125 Build systems are @code{<build-system>} objects. The interface to
7126 create and manipulate them is provided by the @code{(guix build-system)}
7127 module, and actual build systems are exported by specific modules.
7129 @cindex bag (low-level package representation)
7130 Under the hood, build systems first compile package objects to
7131 @dfn{bags}. A @dfn{bag} is like a package, but with less
7132 ornamentation---in other words, a bag is a lower-level representation of
7133 a package, which includes all the inputs of that package, including some
7134 that were implicitly added by the build system. This intermediate
7135 representation is then compiled to a derivation (@pxref{Derivations}).
7136 The @code{package-with-c-toolchain} is an example of a way to change the
7137 implicit inputs that a package's build system pulls in (@pxref{package
7138 Reference, @code{package-with-c-toolchain}}).
7140 Build systems accept an optional list of @dfn{arguments}. In package
7141 definitions, these are passed @i{via} the @code{arguments} field
7142 (@pxref{Defining Packages}). They are typically keyword arguments
7143 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
7144 Guile Reference Manual}). The value of these arguments is usually
7145 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
7146 by the daemon (@pxref{Derivations}).
7148 The main build system is @code{gnu-build-system}, which implements the
7149 standard build procedure for GNU and many other packages. It
7150 is provided by the @code{(guix build-system gnu)} module.
7152 @defvr {Scheme Variable} gnu-build-system
7153 @code{gnu-build-system} represents the GNU Build System, and variants
7154 thereof (@pxref{Configuration, configuration and makefile conventions,,
7155 standards, GNU Coding Standards}).
7157 @cindex build phases
7158 In a nutshell, packages using it are configured, built, and installed with
7159 the usual @code{./configure && make && make check && make install}
7160 command sequence. In practice, a few additional steps are often needed.
7161 All these steps are split up in separate @dfn{phases},
7162 notably@footnote{Please see the @code{(guix build gnu-build-system)}
7163 modules for more details about the build phases.}:
7167 Unpack the source tarball, and change the current directory to the
7168 extracted source tree. If the source is actually a directory, copy it
7169 to the build tree, and enter that directory.
7171 @item patch-source-shebangs
7172 Patch shebangs encountered in source files so they refer to the right
7173 store file names. For instance, this changes @code{#!/bin/sh} to
7174 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
7177 Run the @file{configure} script with a number of default options, such
7178 as @option{--prefix=/gnu/store/@dots{}}, as well as the options specified
7179 by the @code{#:configure-flags} argument.
7182 Run @code{make} with the list of flags specified with
7183 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
7184 (the default), build with @code{make -j}.
7187 Run @code{make check}, or some other target specified with
7188 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
7189 @code{#:parallel-tests?} argument is true (the default), run @code{make
7193 Run @code{make install} with the flags listed in @code{#:make-flags}.
7195 @item patch-shebangs
7196 Patch shebangs on the installed executable files.
7199 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
7200 is false), copying them to the @code{debug} output when available
7201 (@pxref{Installing Debugging Files}).
7204 @vindex %standard-phases
7205 The build-side module @code{(guix build gnu-build-system)} defines
7206 @code{%standard-phases} as the default list of build phases.
7207 @code{%standard-phases} is a list of symbol/procedure pairs, where the
7208 procedure implements the actual phase.
7210 @xref{Build Phases}, for more info on build phases and ways to customize
7213 In addition, this build system ensures that the ``standard'' environment
7214 for GNU packages is available. This includes tools such as GCC, libc,
7215 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
7216 build-system gnu)} module for a complete list). We call these the
7217 @dfn{implicit inputs} of a package, because package definitions do not
7218 have to mention them.
7221 Other @code{<build-system>} objects are defined to support other
7222 conventions and tools used by free software packages. They inherit most
7223 of @code{gnu-build-system}, and differ mainly in the set of inputs
7224 implicitly added to the build process, and in the list of phases
7225 executed. Some of these build systems are listed below.
7227 @defvr {Scheme Variable} ant-build-system
7228 This variable is exported by @code{(guix build-system ant)}. It
7229 implements the build procedure for Java packages that can be built with
7230 @url{https://ant.apache.org/, Ant build tool}.
7232 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
7233 provided by the @code{icedtea} package to the set of inputs. Different
7234 packages can be specified with the @code{#:ant} and @code{#:jdk}
7235 parameters, respectively.
7237 When the original package does not provide a suitable Ant build file,
7238 the parameter @code{#:jar-name} can be used to generate a minimal Ant
7239 build file @file{build.xml} with tasks to build the specified jar
7240 archive. In this case the parameter @code{#:source-dir} can be used to
7241 specify the source sub-directory, defaulting to ``src''.
7243 The @code{#:main-class} parameter can be used with the minimal ant
7244 buildfile to specify the main class of the resulting jar. This makes the
7245 jar file executable. The @code{#:test-include} parameter can be used to
7246 specify the list of junit tests to run. It defaults to
7247 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
7248 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
7249 because abstract classes cannot be run as tests.
7251 The parameter @code{#:build-target} can be used to specify the Ant task
7252 that should be run during the @code{build} phase. By default the
7253 ``jar'' task will be run.
7257 @defvr {Scheme Variable} android-ndk-build-system
7258 @cindex Android distribution
7259 @cindex Android NDK build system
7260 This variable is exported by @code{(guix build-system android-ndk)}. It
7261 implements a build procedure for Android NDK (native development kit)
7262 packages using a Guix-specific build process.
7264 The build system assumes that packages install their public interface
7265 (header) files to the subdirectory @file{include} of the @code{out} output and
7266 their libraries to the subdirectory @file{lib} the @code{out} output.
7268 It's also assumed that the union of all the dependencies of a package
7269 has no conflicting files.
7271 For the time being, cross-compilation is not supported - so right now
7272 the libraries and header files are assumed to be host tools.
7276 @defvr {Scheme Variable} asdf-build-system/source
7277 @defvrx {Scheme Variable} asdf-build-system/sbcl
7278 @defvrx {Scheme Variable} asdf-build-system/ecl
7280 These variables, exported by @code{(guix build-system asdf)}, implement
7281 build procedures for Common Lisp packages using
7282 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
7283 definition facility for Common Lisp programs and libraries.
7285 The @code{asdf-build-system/source} system installs the packages in
7286 source form, and can be loaded using any common lisp implementation, via
7287 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
7288 systems in the format which a particular implementation understands.
7289 These build systems can also be used to produce executable programs, or
7290 lisp images which contain a set of packages pre-loaded.
7292 The build system uses naming conventions. For binary packages, the
7293 package name should be prefixed with the lisp implementation, such as
7294 @code{sbcl-} for @code{asdf-build-system/sbcl}.
7296 Additionally, the corresponding source package should be labeled using
7297 the same convention as python packages (see @ref{Python Modules}), using
7298 the @code{cl-} prefix.
7300 In order to create executable programs and images, the build-side
7301 procedures @code{build-program} and @code{build-image} can be used.
7302 They should be called in a build phase after the
7303 @code{create-asdf-configuration} phase, so that the system which was
7304 just built can be used within the resulting image. @code{build-program}
7305 requires a list of Common Lisp expressions to be passed as the
7306 @code{#:entry-program} argument.
7308 By default, all the @file{.asd} files present in the sources are read to
7309 find system definitions. The @code{#:asd-files} parameter can be used
7310 to specify the list of @file{.asd} files to read. Furthermore, if the
7311 package defines a system for its tests in a separate file, it will be
7312 loaded before the tests are run if it is specified by the
7313 @code{#:test-asd-file} parameter. If it is not set, the files
7314 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
7315 and @code{test.asd} will be tried if they exist.
7317 If for some reason the package must be named in a different way than the
7318 naming conventions suggest, or if several systems must be compiled, the
7319 @code{#:asd-systems} parameter can be used to specify the list of system
7324 @defvr {Scheme Variable} cargo-build-system
7325 @cindex Rust programming language
7326 @cindex Cargo (Rust build system)
7327 This variable is exported by @code{(guix build-system cargo)}. It
7328 supports builds of packages using Cargo, the build tool of the
7329 @uref{https://www.rust-lang.org, Rust programming language}.
7331 It adds @code{rustc} and @code{cargo} to the set of inputs.
7332 A different Rust package can be specified with the @code{#:rust} parameter.
7334 Regular cargo dependencies should be added to the package definition via the
7335 @code{#:cargo-inputs} parameter as a list of name and spec pairs, where the
7336 spec can be a package or a source definition. Note that the spec must
7337 evaluate to a path to a gzipped tarball which includes a @code{Cargo.toml}
7338 file at its root, or it will be ignored. Similarly, cargo dev-dependencies
7339 should be added to the package definition via the
7340 @code{#:cargo-development-inputs} parameter.
7342 In its @code{configure} phase, this build system will make any source inputs
7343 specified in the @code{#:cargo-inputs} and @code{#:cargo-development-inputs}
7344 parameters available to cargo. It will also remove an included
7345 @code{Cargo.lock} file to be recreated by @code{cargo} during the
7346 @code{build} phase. The @code{install} phase installs the binaries
7347 defined by the crate.
7350 @defvr {Scheme Variable} chicken-build-system
7351 This variable is exported by @code{(guix build-system chicken)}. It
7352 builds @uref{https://call-cc.org/, CHICKEN Scheme} modules, also called
7353 ``eggs'' or ``extensions''. CHICKEN generates C source code, which then
7354 gets compiled by a C compiler, in this case GCC.
7356 This build system adds @code{chicken} to the package inputs, as well as
7357 the packages of @code{gnu-build-system}.
7359 The build system can't (yet) deduce the egg's name automatically, so just like
7360 with @code{go-build-system} and its @code{#:import-path}, you should define
7361 @code{#:egg-name} in the package's @code{arguments} field.
7363 For example, if you are packaging the @code{srfi-1} egg:
7366 (arguments '(#:egg-name "srfi-1"))
7369 Egg dependencies must be defined in @code{propagated-inputs}, not @code{inputs}
7370 because CHICKEN doesn't embed absolute references in compiled eggs.
7371 Test dependencies should go to @code{native-inputs}, as usual.
7374 @defvr {Scheme Variable} copy-build-system
7375 This variable is exported by @code{(guix build-system copy)}. It
7376 supports builds of simple packages that don't require much compiling,
7377 mostly just moving files around.
7379 It adds much of the @code{gnu-build-system} packages to the set of
7380 inputs. Because of this, the @code{copy-build-system} does not require
7381 all the boilerplate code often needed for the
7382 @code{trivial-build-system}.
7384 To further simplify the file installation process, an
7385 @code{#:install-plan} argument is exposed to let the packager specify
7386 which files go where. The install plan is a list of @code{(@var{source}
7387 @var{target} [@var{filters}])}. @var{filters} are optional.
7390 @item When @var{source} matches a file or directory without trailing slash, install it to @var{target}.
7392 @item If @var{target} has a trailing slash, install @var{source} basename beneath @var{target}.
7393 @item Otherwise install @var{source} as @var{target}.
7396 @item When @var{source} is a directory with a trailing slash, or when @var{filters} are used,
7397 the trailing slash of @var{target} is implied with the same meaning
7400 @item Without @var{filters}, install the full @var{source} @emph{content} to @var{target}.
7401 @item With @var{filters} among @code{#:include}, @code{#:include-regexp}, @code{#:exclude},
7402 @code{#:exclude-regexp}, only select files are installed depending on
7403 the filters. Each filters is specified by a list of strings.
7405 @item With @code{#:include}, install all the files which the path suffix matches
7406 at least one of the elements in the given list.
7407 @item With @code{#:include-regexp}, install all the files which the
7408 subpaths match at least one of the regular expressions in the given
7410 @item The @code{#:exclude} and @code{#:exclude-regexp} filters
7411 are the complement of their inclusion counterpart. Without @code{#:include} flags,
7412 install all files but those matching the exclusion filters.
7413 If both inclusions and exclusions are specified, the exclusions are done
7414 on top of the inclusions.
7417 In all cases, the paths relative to @var{source} are preserved within
7424 @item @code{("foo/bar" "share/my-app/")}: Install @file{bar} to @file{share/my-app/bar}.
7425 @item @code{("foo/bar" "share/my-app/baz")}: Install @file{bar} to @file{share/my-app/baz}.
7426 @item @code{("foo/" "share/my-app")}: Install the content of @file{foo} inside @file{share/my-app},
7427 e.g., install @file{foo/sub/file} to @file{share/my-app/sub/file}.
7428 @item @code{("foo/" "share/my-app" #:include ("sub/file"))}: Install only @file{foo/sub/file} to
7429 @file{share/my-app/sub/file}.
7430 @item @code{("foo/sub" "share/my-app" #:include ("file"))}: Install @file{foo/sub/file} to
7431 @file{share/my-app/file}.
7436 @cindex Clojure (programming language)
7437 @cindex simple Clojure build system
7438 @defvr {Scheme Variable} clojure-build-system
7439 This variable is exported by @code{(guix build-system clojure)}. It implements
7440 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
7441 using plain old @code{compile} in Clojure. Cross-compilation is not supported
7444 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
7445 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
7446 @code{#:zip} parameters, respectively.
7448 A list of source directories, test directories and jar names can be specified
7449 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
7450 parameters, respectively. Compile directory and main class can be specified
7451 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
7452 Other parameters are documented below.
7454 This build system is an extension of @code{ant-build-system}, but with the
7455 following phases changed:
7460 This phase calls @code{compile} in Clojure to compile source files and runs
7461 @command{jar} to create jars from both source files and compiled files
7462 according to the include list and exclude list specified in
7463 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
7464 has priority over the include list. These lists consist of symbols
7465 representing Clojure libraries or the special keyword @code{#:all} representing
7466 all Clojure libraries found under the source directories. The parameter
7467 @code{#:omit-source?} decides if source should be included into the jars.
7470 This phase runs tests according to the include list and exclude list specified
7471 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
7472 meanings are analogous to that of @code{#:aot-include} and
7473 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
7474 stands for all Clojure libraries found under the test directories. The
7475 parameter @code{#:tests?} decides if tests should be run.
7478 This phase installs all jars built previously.
7481 Apart from the above, this build system also contains an additional phase:
7486 This phase installs all top-level files with base name matching
7487 @code{%doc-regex}. A different regex can be specified with the
7488 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
7489 directories specified in @code{#:doc-dirs} are installed as well.
7493 @defvr {Scheme Variable} cmake-build-system
7494 This variable is exported by @code{(guix build-system cmake)}. It
7495 implements the build procedure for packages using the
7496 @url{https://www.cmake.org, CMake build tool}.
7498 It automatically adds the @code{cmake} package to the set of inputs.
7499 Which package is used can be specified with the @code{#:cmake}
7502 The @code{#:configure-flags} parameter is taken as a list of flags
7503 passed to the @command{cmake} command. The @code{#:build-type}
7504 parameter specifies in abstract terms the flags passed to the compiler;
7505 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
7506 debugging information''), which roughly means that code is compiled with
7507 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
7510 @defvr {Scheme Variable} dune-build-system
7511 This variable is exported by @code{(guix build-system dune)}. It
7512 supports builds of packages using @uref{https://dune.build/, Dune}, a build
7513 tool for the OCaml programming language. It is implemented as an extension
7514 of the @code{ocaml-build-system} which is described below. As such, the
7515 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
7518 It automatically adds the @code{dune} package to the set of inputs.
7519 Which package is used can be specified with the @code{#:dune}
7522 There is no @code{configure} phase because dune packages typically don't
7523 need to be configured. The @code{#:build-flags} parameter is taken as a
7524 list of flags passed to the @code{dune} command during the build.
7526 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
7527 command instead of the more recent @code{dune} command while building
7528 a package. Its default value is @code{#f}.
7530 The @code{#:package} parameter can be passed to specify a package name, which
7531 is useful when a package contains multiple packages and you want to build
7532 only one of them. This is equivalent to passing the @code{-p} argument to
7536 @defvr {Scheme Variable} go-build-system
7537 This variable is exported by @code{(guix build-system go)}. It
7538 implements a build procedure for Go packages using the standard
7539 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
7540 Go build mechanisms}.
7542 The user is expected to provide a value for the key @code{#:import-path}
7543 and, in some cases, @code{#:unpack-path}. The
7544 @url{https://golang.org/doc/code.html#ImportPaths, import path}
7545 corresponds to the file system path expected by the package's build
7546 scripts and any referring packages, and provides a unique way to
7547 refer to a Go package. It is typically based on a combination of the
7548 package source code's remote URI and file system hierarchy structure. In
7549 some cases, you will need to unpack the package's source code to a
7550 different directory structure than the one indicated by the import path,
7551 and @code{#:unpack-path} should be used in such cases.
7553 Packages that provide Go libraries should install their source code into
7554 the built output. The key @code{#:install-source?}, which defaults to
7555 @code{#t}, controls whether or not the source code is installed. It can
7556 be set to @code{#f} for packages that only provide executable files.
7559 @defvr {Scheme Variable} glib-or-gtk-build-system
7560 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
7561 is intended for use with packages making use of GLib or GTK+.
7563 This build system adds the following two phases to the ones defined by
7564 @code{gnu-build-system}:
7567 @item glib-or-gtk-wrap
7568 The phase @code{glib-or-gtk-wrap} ensures that programs in
7569 @file{bin/} are able to find GLib ``schemas'' and
7570 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
7571 modules}. This is achieved by wrapping the programs in launch scripts
7572 that appropriately set the @env{XDG_DATA_DIRS} and @env{GTK_PATH}
7573 environment variables.
7575 It is possible to exclude specific package outputs from that wrapping
7576 process by listing their names in the
7577 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
7578 when an output is known not to contain any GLib or GTK+ binaries, and
7579 where wrapping would gratuitously add a dependency of that output on
7582 @item glib-or-gtk-compile-schemas
7583 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
7584 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
7585 GSettings schemas} of GLib are compiled. Compilation is performed by the
7586 @command{glib-compile-schemas} program. It is provided by the package
7587 @code{glib:bin} which is automatically imported by the build system.
7588 The @code{glib} package providing @command{glib-compile-schemas} can be
7589 specified with the @code{#:glib} parameter.
7592 Both phases are executed after the @code{install} phase.
7595 @defvr {Scheme Variable} guile-build-system
7596 This build system is for Guile packages that consist exclusively of Scheme
7597 code and that are so lean that they don't even have a makefile, let alone a
7598 @file{configure} script. It compiles Scheme code using @command{guild
7599 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
7600 installs the @file{.scm} and @file{.go} files in the right place. It also
7601 installs documentation.
7603 This build system supports cross-compilation by using the
7604 @option{--target} option of @samp{guild compile}.
7606 Packages built with @code{guile-build-system} must provide a Guile package in
7607 their @code{native-inputs} field.
7610 @defvr {Scheme Variable} julia-build-system
7611 This variable is exported by @code{(guix build-system julia)}. It
7612 implements the build procedure used by @uref{https://julialang.org/,
7613 julia} packages, which essentially is similar to running @samp{julia -e
7614 'using Pkg; Pkg.add(package)'} in an environment where
7615 @env{JULIA_LOAD_PATH} contains the paths to all Julia package inputs.
7616 Tests are run with @code{Pkg.test}.
7618 Julia packages require the source @code{file-name} to be the real name of the
7619 package, correctly capitalized.
7621 For packages requiring shared library dependencies, you may need to write the
7622 @file{/deps/deps.jl} file manually. It's usually a line of @code{const
7623 variable = /gnu/store/library.so} for each dependency, plus a void function
7624 @code{check_deps() = nothing}.
7626 Some older packages that aren't using @file{Package.toml} yet, will require
7627 this file to be created, too. The function @code{julia-create-package-toml}
7628 helps creating the file. You need to pass the outputs and the source of the
7629 package, it's name (the same as the @code{file-name} parameter), the package
7630 uuid, the package version, and a list of dependencies specified by their name
7634 @defvr {Scheme Variable} maven-build-system
7635 This variable is exported by @code{(guix build-system maven)}. It implements
7636 a build procedure for @uref{https://maven.apache.org, Maven} packages. Maven
7637 is a dependency and lifecycle management tool for Java. A user of Maven
7638 specifies dependencies and plugins in a @file{pom.xml} file that Maven reads.
7639 When Maven does not have one of the dependencies or plugins in its repository,
7640 it will download them and use them to build the package.
7642 The maven build system ensures that maven will not try to download any
7643 dependency by running in offline mode. Maven will fail if a dependency is
7644 missing. Before running Maven, the @file{pom.xml} (and subprojects) are
7645 modified to specify the version of dependencies and plugins that match the
7646 versions available in the guix build environment. Dependencies and plugins
7647 must be installed in the fake maven repository at @file{lib/m2}, and are
7648 symlinked into a proper repository before maven is run. Maven is instructed
7649 to use that repository for the build and installs built artifacts there.
7650 Changed files are copied to the @file{lib/m2} directory of the package output.
7652 You can specify a @file{pom.xml} file with the @code{#:pom-file} argument,
7653 or let the build system use the default @file{pom.xml} file in the sources.
7655 In case you need to specify a dependency's version manually, you can use the
7656 @code{#:local-packages} argument. It takes an association list where the key
7657 is the groupId of the package and its value is an association list where the
7658 key is the artifactId of the package and its value is the version you want to
7659 override in the @file{pom.xml}.
7661 Some packages use dependencies or plugins that are not useful at runtime nor
7662 at build time in Guix. You can alter the @file{pom.xml} file to remove them
7663 using the @code{#:exclude} argument. Its value is an association list where
7664 the key is the groupId of the plugin or dependency you want to remove, and
7665 the value is a list of artifactId you want to remove.
7667 You can override the default @code{jdk} and @code{maven} packages with the
7668 corresponding argument, @code{#:jdk} and @code{#:maven}.
7670 The @code{#:maven-plugins} argument is a list of maven plugins used during
7671 the build, with the same format as the @code{inputs} fields of the package
7672 declaration. Its default value is @code{(default-maven-plugins)} which is
7676 @defvr {Scheme Variable} minify-build-system
7677 This variable is exported by @code{(guix build-system minify)}. It
7678 implements a minification procedure for simple JavaScript packages.
7680 It adds @code{uglify-js} to the set of inputs and uses it to compress
7681 all JavaScript files in the @file{src} directory. A different minifier
7682 package can be specified with the @code{#:uglify-js} parameter, but it
7683 is expected that the package writes the minified code to the standard
7686 When the input JavaScript files are not all located in the @file{src}
7687 directory, the parameter @code{#:javascript-files} can be used to
7688 specify a list of file names to feed to the minifier.
7691 @defvr {Scheme Variable} ocaml-build-system
7692 This variable is exported by @code{(guix build-system ocaml)}. It implements
7693 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
7694 of choosing the correct set of commands to run for each package. OCaml
7695 packages can expect many different commands to be run. This build system will
7698 When the package has a @file{setup.ml} file present at the top-level, it will
7699 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
7700 @code{ocaml setup.ml -install}. The build system will assume that this file
7701 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
7702 care of setting the prefix and enabling tests if they are not disabled. You
7703 can pass configure and build flags with the @code{#:configure-flags} and
7704 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
7705 set of flags used to enable tests. The @code{#:use-make?} key can be used to
7706 bypass this system in the build and install phases.
7708 When the package has a @file{configure} file, it is assumed that it is a
7709 hand-made configure script that requires a different argument format than
7710 in the @code{gnu-build-system}. You can add more flags with the
7711 @code{#:configure-flags} key.
7713 When the package has a @file{Makefile} file (or @code{#:use-make?} is
7714 @code{#t}), it will be used and more flags can be passed to the build and
7715 install phases with the @code{#:make-flags} key.
7717 Finally, some packages do not have these files and use a somewhat standard
7718 location for its build system. In that case, the build system will run
7719 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
7720 providing the path to the required findlib module. Additional flags can
7721 be passed via the @code{#:build-flags} key. Install is taken care of by
7722 @command{opam-installer}. In this case, the @code{opam} package must
7723 be added to the @code{native-inputs} field of the package definition.
7725 Note that most OCaml packages assume they will be installed in the same
7726 directory as OCaml, which is not what we want in guix. In particular, they
7727 will install @file{.so} files in their module's directory, which is usually
7728 fine because it is in the OCaml compiler directory. In guix though, these
7729 libraries cannot be found and we use @env{CAML_LD_LIBRARY_PATH}. This
7730 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
7731 @file{.so} libraries should be installed.
7734 @defvr {Scheme Variable} python-build-system
7735 This variable is exported by @code{(guix build-system python)}. It
7736 implements the more or less standard build procedure used by Python
7737 packages, which consists in running @code{python setup.py build} and
7738 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
7740 For packages that install stand-alone Python programs under @code{bin/},
7741 it takes care of wrapping these programs so that their @env{PYTHONPATH}
7742 environment variable points to all the Python libraries they depend on.
7744 Which Python package is used to perform the build can be specified with
7745 the @code{#:python} parameter. This is a useful way to force a package
7746 to be built for a specific version of the Python interpreter, which
7747 might be necessary if the package is only compatible with a single
7748 interpreter version.
7750 By default guix calls @code{setup.py} under control of
7751 @code{setuptools}, much like @command{pip} does. Some packages are not
7752 compatible with setuptools (and pip), thus you can disable this by
7753 setting the @code{#:use-setuptools?} parameter to @code{#f}.
7756 @defvr {Scheme Variable} perl-build-system
7757 This variable is exported by @code{(guix build-system perl)}. It
7758 implements the standard build procedure for Perl packages, which either
7759 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
7760 followed by @code{Build} and @code{Build install}; or in running
7761 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
7762 @code{make} and @code{make install}, depending on which of
7763 @code{Build.PL} or @code{Makefile.PL} is present in the package
7764 distribution. Preference is given to the former if both @code{Build.PL}
7765 and @code{Makefile.PL} exist in the package distribution. This
7766 preference can be reversed by specifying @code{#t} for the
7767 @code{#:make-maker?} parameter.
7769 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
7770 passes flags specified by the @code{#:make-maker-flags} or
7771 @code{#:module-build-flags} parameter, respectively.
7773 Which Perl package is used can be specified with @code{#:perl}.
7776 @defvr {Scheme Variable} qt-build-system
7777 This variable is exported by @code{(guix build-system qt)}. It
7778 is intended for use with applications using Qt or KDE.
7780 This build system adds the following two phases to the ones defined by
7781 @code{cmake-build-system}:
7785 The phase @code{check-setup} prepares the environment for running
7786 the checks as commonly used by Qt test programs.
7787 For now this only sets some environment variables:
7788 @code{QT_QPA_PLATFORM=offscreen},
7789 @code{DBUS_FATAL_WARNINGS=0} and
7790 @code{CTEST_OUTPUT_ON_FAILURE=1}.
7792 This phase is added before the @code{check} phase.
7793 It's a separate phase to ease adjusting if necessary.
7796 The phase @code{qt-wrap}
7797 searches for Qt5 plugin paths, QML paths and some XDG in the inputs
7798 and output. In case some path is found, all programs in the output's
7799 @file{bin/}, @file{sbin/}, @file{libexec/} and @file{lib/libexec/} directories
7800 are wrapped in scripts defining the necessary environment variables.
7802 It is possible to exclude specific package outputs from that wrapping process
7803 by listing their names in the @code{#:qt-wrap-excluded-outputs} parameter.
7804 This is useful when an output is known not to contain any Qt binaries, and
7805 where wrapping would gratuitously add a dependency of that output on Qt, KDE,
7808 This phase is added after the @code{install} phase.
7812 @defvr {Scheme Variable} r-build-system
7813 This variable is exported by @code{(guix build-system r)}. It
7814 implements the build procedure used by @uref{https://r-project.org, R}
7815 packages, which essentially is little more than running @samp{R CMD
7816 INSTALL --library=/gnu/store/@dots{}} in an environment where
7817 @env{R_LIBS_SITE} contains the paths to all R package inputs. Tests are
7818 run after installation using the R function
7819 @code{tools::testInstalledPackage}.
7822 @defvr {Scheme Variable} rakudo-build-system
7823 This variable is exported by @code{(guix build-system rakudo)}. It
7824 implements the build procedure used by @uref{https://rakudo.org/,
7825 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
7826 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
7827 installs the binaries, library files and the resources, as well as wrap
7828 the files under the @code{bin/} directory. Tests can be skipped by
7829 passing @code{#f} to the @code{tests?} parameter.
7831 Which rakudo package is used can be specified with @code{rakudo}.
7832 Which perl6-tap-harness package used for the tests can be specified with
7833 @code{#:prove6} or removed by passing @code{#f} to the
7834 @code{with-prove6?} parameter.
7835 Which perl6-zef package used for tests and installing can be specified
7836 with @code{#:zef} or removed by passing @code{#f} to the
7837 @code{with-zef?} parameter.
7840 @defvr {Scheme Variable} texlive-build-system
7841 This variable is exported by @code{(guix build-system texlive)}. It is
7842 used to build TeX packages in batch mode with a specified engine. The
7843 build system sets the @env{TEXINPUTS} variable to find all TeX source
7844 files in the inputs.
7846 By default it runs @code{luatex} on all files ending on @code{ins}. A
7847 different engine and format can be specified with the
7848 @code{#:tex-format} argument. Different build targets can be specified
7849 with the @code{#:build-targets} argument, which expects a list of file
7850 names. The build system adds only @code{texlive-bin} and
7851 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
7852 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
7853 and @code{#:texlive-latex-base}, respectively.
7855 The @code{#:tex-directory} parameter tells the build system where to
7856 install the built files under the texmf tree.
7859 @defvr {Scheme Variable} ruby-build-system
7860 This variable is exported by @code{(guix build-system ruby)}. It
7861 implements the RubyGems build procedure used by Ruby packages, which
7862 involves running @code{gem build} followed by @code{gem install}.
7864 The @code{source} field of a package that uses this build system
7865 typically references a gem archive, since this is the format that Ruby
7866 developers use when releasing their software. The build system unpacks
7867 the gem archive, potentially patches the source, runs the test suite,
7868 repackages the gem, and installs it. Additionally, directories and
7869 tarballs may be referenced to allow building unreleased gems from Git or
7870 a traditional source release tarball.
7872 Which Ruby package is used can be specified with the @code{#:ruby}
7873 parameter. A list of additional flags to be passed to the @command{gem}
7874 command can be specified with the @code{#:gem-flags} parameter.
7877 @defvr {Scheme Variable} waf-build-system
7878 This variable is exported by @code{(guix build-system waf)}. It
7879 implements a build procedure around the @code{waf} script. The common
7880 phases---@code{configure}, @code{build}, and @code{install}---are
7881 implemented by passing their names as arguments to the @code{waf}
7884 The @code{waf} script is executed by the Python interpreter. Which
7885 Python package is used to run the script can be specified with the
7886 @code{#:python} parameter.
7889 @defvr {Scheme Variable} scons-build-system
7890 This variable is exported by @code{(guix build-system scons)}. It
7891 implements the build procedure used by the SCons software construction
7892 tool. This build system runs @code{scons} to build the package,
7893 @code{scons test} to run tests, and then @code{scons install} to install
7896 Additional flags to be passed to @code{scons} can be specified with the
7897 @code{#:scons-flags} parameter. The default build and install targets
7898 can be overridden with @code{#:build-targets} and
7899 @code{#:install-targets} respectively. The version of Python used to
7900 run SCons can be specified by selecting the appropriate SCons package
7901 with the @code{#:scons} parameter.
7904 @defvr {Scheme Variable} haskell-build-system
7905 This variable is exported by @code{(guix build-system haskell)}. It
7906 implements the Cabal build procedure used by Haskell packages, which
7907 involves running @code{runhaskell Setup.hs configure
7908 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
7909 Instead of installing the package by running @code{runhaskell Setup.hs
7910 install}, to avoid trying to register libraries in the read-only
7911 compiler store directory, the build system uses @code{runhaskell
7912 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
7913 addition, the build system generates the package documentation by
7914 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
7915 is passed. Optional Haddock parameters can be passed with the help of
7916 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
7917 not found, the build system looks for @code{Setup.lhs} instead.
7919 Which Haskell compiler is used can be specified with the @code{#:haskell}
7920 parameter which defaults to @code{ghc}.
7923 @defvr {Scheme Variable} dub-build-system
7924 This variable is exported by @code{(guix build-system dub)}. It
7925 implements the Dub build procedure used by D packages, which
7926 involves running @code{dub build} and @code{dub run}.
7927 Installation is done by copying the files manually.
7929 Which D compiler is used can be specified with the @code{#:ldc}
7930 parameter which defaults to @code{ldc}.
7933 @defvr {Scheme Variable} emacs-build-system
7934 This variable is exported by @code{(guix build-system emacs)}. It
7935 implements an installation procedure similar to the packaging system
7936 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
7938 It first creates the @code{@code{package}-autoloads.el} file, then it
7939 byte compiles all Emacs Lisp files. Differently from the Emacs
7940 packaging system, the Info documentation files are moved to the standard
7941 documentation directory and the @file{dir} file is deleted. The Elisp
7942 package files are installed directly under @file{share/emacs/site-lisp}.
7945 @defvr {Scheme Variable} font-build-system
7946 This variable is exported by @code{(guix build-system font)}. It
7947 implements an installation procedure for font packages where upstream
7948 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
7949 need to be copied into place. It copies font files to standard
7950 locations in the output directory.
7953 @defvr {Scheme Variable} meson-build-system
7954 This variable is exported by @code{(guix build-system meson)}. It
7955 implements the build procedure for packages that use
7956 @url{https://mesonbuild.com, Meson} as their build system.
7958 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
7959 of inputs, and they can be changed with the parameters @code{#:meson}
7960 and @code{#:ninja} if needed. The default Meson is
7961 @code{meson-for-build}, which is special because it doesn't clear the
7962 @code{RUNPATH} of binaries and libraries when they are installed.
7964 This build system is an extension of @code{gnu-build-system}, but with the
7965 following phases changed to some specific for Meson:
7970 The phase runs @code{meson} with the flags specified in
7971 @code{#:configure-flags}. The flag @option{--buildtype} is always set to
7972 @code{debugoptimized} unless something else is specified in
7973 @code{#:build-type}.
7976 The phase runs @code{ninja} to build the package in parallel by default, but
7977 this can be changed with @code{#:parallel-build?}.
7980 The phase runs @code{ninja} with the target specified in @code{#:test-target},
7981 which is @code{"test"} by default.
7984 The phase runs @code{ninja install} and can not be changed.
7987 Apart from that, the build system also adds the following phases:
7992 This phase ensures that all binaries can find the libraries they need.
7993 It searches for required libraries in subdirectories of the package being
7994 built, and adds those to @code{RUNPATH} where needed. It also removes
7995 references to libraries left over from the build phase by
7996 @code{meson-for-build}, such as test dependencies, that aren't actually
7997 required for the program to run.
7999 @item glib-or-gtk-wrap
8000 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
8001 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
8003 @item glib-or-gtk-compile-schemas
8004 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
8005 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
8009 @defvr {Scheme Variable} linux-module-build-system
8010 @code{linux-module-build-system} allows building Linux kernel modules.
8012 @cindex build phases
8013 This build system is an extension of @code{gnu-build-system}, but with the
8014 following phases changed:
8019 This phase configures the environment so that the Linux kernel's Makefile
8020 can be used to build the external kernel module.
8023 This phase uses the Linux kernel's Makefile in order to build the external
8027 This phase uses the Linux kernel's Makefile in order to install the external
8031 It is possible and useful to specify the Linux kernel to use for building
8032 the module (in the @code{arguments} form of a package using the
8033 @code{linux-module-build-system}, use the key @code{#:linux} to specify it).
8036 @defvr {Scheme Variable} node-build-system
8037 This variable is exported by @code{(guix build-system node)}. It
8038 implements the build procedure used by @uref{https://nodejs.org,
8039 Node.js}, which implements an approximation of the @code{npm install}
8040 command, followed by an @code{npm test} command.
8042 Which Node.js package is used to interpret the @code{npm} commands can
8043 be specified with the @code{#:node} parameter which defaults to
8047 Lastly, for packages that do not need anything as sophisticated, a
8048 ``trivial'' build system is provided. It is trivial in the sense that
8049 it provides basically no support: it does not pull any implicit inputs,
8050 and does not have a notion of build phases.
8052 @defvr {Scheme Variable} trivial-build-system
8053 This variable is exported by @code{(guix build-system trivial)}.
8055 This build system requires a @code{#:builder} argument. This argument
8056 must be a Scheme expression that builds the package output(s)---as
8057 with @code{build-expression->derivation} (@pxref{Derivations,
8058 @code{build-expression->derivation}}).
8062 @section Build Phases
8064 @cindex build phases, for packages
8065 Almost all package build systems implement a notion @dfn{build phases}:
8066 a sequence of actions that the build system executes, when you build the
8067 package, leading to the installed byproducts in the store. A notable
8068 exception is the ``bare-bones'' @code{trivial-build-system}
8069 (@pxref{Build Systems}).
8071 As discussed in the previous section, those build systems provide a
8072 standard list of phases. For @code{gnu-build-system}, the standard
8073 phases include an @code{unpack} phase to unpack the source code tarball,
8074 a @command{configure} phase to run @code{./configure}, a @code{build}
8075 phase to run @command{make}, and (among others) an @code{install} phase
8076 to run @command{make install}; @pxref{Build Systems}, for a more
8077 detailed view of these phases. Likewise, @code{cmake-build-system}
8078 inherits these phases, but its @code{configure} phase runs
8079 @command{cmake} instead of @command{./configure}. Other build systems,
8080 such as @code{python-build-system}, have a wholly different list of
8081 standard phases. All this code runs on the @dfn{build side}: it is
8082 evaluated when you actually build the package, in a dedicated build
8083 process spawned by the build daemon (@pxref{Invoking guix-daemon}).
8085 Build phases are represented as association lists or ``alists''
8086 (@pxref{Association Lists,,, guile, GNU Guile Reference Manual}) where
8087 each key is a symbol for the name of the phase and the associated value
8088 is a procedure that accepts an arbitrary number of arguments. By
8089 convention, those procedures receive information about the build in the
8090 form of @dfn{keyword parameters}, which they can use or ignore.
8092 For example, here is how @code{(guix build gnu-build-system)} defines
8093 @code{%standard-phases}, the variable holding its alist of build
8094 phases@footnote{We present a simplified view of those build phases, but
8095 do take a look at @code{(guix build gnu-build-system)} to see all the
8099 ;; The build phases of 'gnu-build-system'.
8101 (define* (unpack #:key source #:allow-other-keys)
8102 ;; Extract the source tarball.
8103 (invoke "tar" "xvf" source))
8105 (define* (configure #:key outputs #:allow-other-keys)
8106 ;; Run the 'configure' script. Install to output "out".
8107 (let ((out (assoc-ref outputs "out")))
8108 (invoke "./configure"
8109 (string-append "--prefix=" out))))
8111 (define* (build #:allow-other-keys)
8115 (define* (check #:key (test-target "check") (tests? #true)
8117 ;; Run the test suite.
8119 (invoke "make" test-target)
8120 (display "test suite not run\n")))
8122 (define* (install #:allow-other-keys)
8123 ;; Install files to the prefix 'configure' specified.
8124 (invoke "make" "install"))
8126 (define %standard-phases
8127 ;; The list of standard phases (quite a few are omitted
8128 ;; for brevity). Each element is a symbol/procedure pair.
8129 (list (cons 'unpack unpack)
8130 (cons 'configure configure)
8133 (cons 'install install)))
8136 This shows how @code{%standard-phases} is defined as a list of
8137 symbol/procedure pairs (@pxref{Pairs,,, guile, GNU Guile Reference
8138 Manual}). The first pair associates the @code{unpack} procedure with
8139 the @code{unpack} symbol---a name; the second pair defines the
8140 @code{configure} phase similarly, and so on. When building a package
8141 that uses @code{gnu-build-system} with its default list of phases, those
8142 phases are executed sequentially. You can see the name of each phase
8143 started and completed in the build log of packages that you build.
8145 Let's now look at the procedures themselves. Each one is defined with
8146 @code{define*}: @code{#:key} lists keyword parameters the procedure
8147 accepts, possibly with a default value, and @code{#:allow-other-keys}
8148 specifies that other keyword parameters are ignored (@pxref{Optional
8149 Arguments,,, guile, GNU Guile Reference Manual}).
8151 The @code{unpack} procedure honors the @code{source} parameter, which
8152 the build system uses to pass the file name of the source tarball (or
8153 version control checkout), and it ignores other parameters. The
8154 @code{configure} phase only cares about the @code{outputs} parameter, an
8155 alist mapping package output names to their store file name
8156 (@pxref{Packages with Multiple Outputs}). It extracts the file name of
8157 for @code{out}, the default output, and passes it to
8158 @command{./configure} as the installation prefix, meaning that
8159 @command{make install} will eventually copy all the files in that
8160 directory (@pxref{Configuration, configuration and makefile
8161 conventions,, standards, GNU Coding Standards}). @code{build} and
8162 @code{install} ignore all their arguments. @code{check} honors the
8163 @code{test-target} argument, which specifies the name of the Makefile
8164 target to run tests; it prints a message and skips tests when
8165 @code{tests?} is false.
8167 @cindex build phases, customizing
8168 The list of phases used for a particular package can be changed with the
8169 @code{#:phases} parameter of the build system. Changing the set of
8170 build phases boils down to building a new alist of phases based on the
8171 @code{%standard-phases} alist described above. This can be done with
8172 standard alist procedures such as @code{alist-delete} (@pxref{SRFI-1
8173 Association Lists,,, guile, GNU Guile Reference Manual}); however, it is
8174 more convenient to do so with @code{modify-phases} (@pxref{Build
8175 Utilities, @code{modify-phases}}).
8177 Here is an example of a package definition that removes the
8178 @code{configure} phase of @code{%standard-phases} and inserts a new
8179 phase before the @code{build} phase, called
8180 @code{set-prefix-in-makefile}:
8183 (define-public example
8186 ;; other fields omitted
8187 (build-system gnu-build-system)
8189 '(#:phases (modify-phases %standard-phases
8191 (add-before 'build 'set-prefix-in-makefile
8192 (lambda* (#:key outputs #:allow-other-keys)
8193 ;; Modify the makefile so that its
8194 ;; 'PREFIX' variable points to "out".
8195 (let ((out (assoc-ref outputs "out")))
8196 (substitute* "Makefile"
8198 (string-append "PREFIX = "
8203 The new phase that is inserted is written as an anonymous procedure,
8204 introduced with @code{lambda*}; it honors the @code{outputs} parameter
8205 we have seen before. @xref{Build Utilities}, for more about the helpers
8206 used by this phase, and for more examples of @code{modify-phases}.
8208 @cindex code staging
8209 @cindex staging, of code
8210 Keep in mind that build phases are code evaluated at the time the
8211 package is actually built. This explains why the whole
8212 @code{modify-phases} expression above is quoted (it comes after the
8213 @code{'} or apostrophe): it is @dfn{staged} for later execution.
8214 @xref{G-Expressions}, for an explanation of code staging and the
8215 @dfn{code strata} involved.
8217 @node Build Utilities
8218 @section Build Utilities
8220 As soon as you start writing non-trivial package definitions
8221 (@pxref{Defining Packages}) or other build actions
8222 (@pxref{G-Expressions}), you will likely start looking for helpers for
8223 ``shell-like'' actions---creating directories, copying and deleting
8224 files recursively, manipulating build phases, and so on. The
8225 @code{(guix build utils)} module provides such utility procedures.
8227 Most build systems load @code{(guix build utils)} (@pxref{Build
8228 Systems}). Thus, when writing custom build phases for your package
8229 definitions, you can usually assume those procedures are in scope.
8231 When writing G-expressions, you can import @code{(guix build utils)} on
8232 the ``build side'' using @code{with-imported-modules} and then put it in
8233 scope with the @code{use-modules} form (@pxref{Using Guile Modules,,,
8234 guile, GNU Guile Reference Manual}):
8237 (with-imported-modules '((guix build utils)) ;import it
8238 (computed-file "empty-tree"
8241 (use-modules (guix build utils))
8243 ;; Happily use its 'mkdir-p' procedure.
8244 (mkdir-p (string-append #$output "/a/b/c")))))
8247 The remainder of this section is the reference for most of the utility
8248 procedures provided by @code{(guix build utils)}.
8250 @c TODO Document what's missing.
8252 @subsection Dealing with Store File Names
8254 This section documents procedures that deal with store file names.
8256 @deffn {Scheme Procedure} %store-directory
8257 Return the directory name of the store.
8260 @deffn {Scheme Procedure} store-file-name? @var{file}
8261 Return true if @var{file} is in the store.
8264 @deffn {Scheme Procedure} strip-store-file-name @var{file}
8265 Strip the @file{/gnu/store} and hash from @var{file}, a store file name.
8266 The result is typically a @code{"@var{package}-@var{version}"} string.
8269 @deffn {Scheme Procedure} package-name->name+version @var{name}
8270 Given @var{name}, a package name like @code{"foo-0.9.1b"}, return two
8271 values: @code{"foo"} and @code{"0.9.1b"}. When the version part is
8272 unavailable, @var{name} and @code{#f} are returned. The first hyphen
8273 followed by a digit is considered to introduce the version part.
8276 @subsection File Types
8278 The procedures below deal with files and file types.
8280 @deffn {Scheme Procedure} directory-exists? @var{dir}
8281 Return @code{#t} if @var{dir} exists and is a directory.
8284 @deffn {Scheme Procedure} executable-file? @var{file}
8285 Return @code{#t} if @var{file} exists and is executable.
8288 @deffn {Scheme Procedure} symbolic-link? @var{file}
8289 Return @code{#t} if @var{file} is a symbolic link (aka. a ``symlink'').
8292 @deffn {Scheme Procedure} elf-file? @var{file}
8293 @deffnx {Scheme Procedure} ar-file? @var{file}
8294 @deffnx {Scheme Procedure} gzip-file? @var{file}
8295 Return @code{#t} if @var{file} is, respectively, an ELF file, an
8296 @code{ar} archive (such as a @file{.a} static library), or a gzip file.
8299 @deffn {Scheme Procedure} reset-gzip-timestamp @var{file} [#:keep-mtime? #t]
8300 If @var{file} is a gzip file, reset its embedded timestamp (as with
8301 @command{gzip --no-name}) and return true. Otherwise return @code{#f}.
8302 When @var{keep-mtime?} is true, preserve @var{file}'s modification time.
8305 @subsection File Manipulation
8307 The following procedures and macros help create, modify, and delete
8308 files. They provide functionality comparable to common shell utilities
8309 such as @command{mkdir -p}, @command{cp -r}, @command{rm -r}, and
8310 @command{sed}. They complement Guile's extensive, but low-level, file
8311 system interface (@pxref{POSIX,,, guile, GNU Guile Reference Manual}).
8313 @deffn {Scheme Syntax} with-directory-excursion @var{directory} @var{body}@dots{}
8314 Run @var{body} with @var{directory} as the process's current directory.
8316 Essentially, this macro changes the current directory to @var{directory}
8317 before evaluating @var{body}, using @code{chdir} (@pxref{Processes,,,
8318 guile, GNU Guile Reference Manual}). It changes back to the initial
8319 directory when the dynamic extent of @var{body} is left, be it @i{via}
8320 normal procedure return or @i{via} a non-local exit such as an
8324 @deffn {Scheme Procedure} mkdir-p @var{dir}
8325 Create directory @var{dir} and all its ancestors.
8328 @deffn {Scheme Procedure} install-file @var{file} @var{directory}
8329 Create @var{directory} if it does not exist and copy @var{file} in there
8330 under the same name.
8333 @deffn {Scheme Procedure} make-file-writable @var{file}
8334 Make @var{file} writable for its owner.
8337 @deffn {Scheme Procedure} copy-recursively @var{source} @var{destination} @
8338 [#:log (current-output-port)] [#:follow-symlinks? #f] [#:keep-mtime? #f]
8339 Copy @var{source} directory to @var{destination}. Follow symlinks if
8340 @var{follow-symlinks?} is true; otherwise, just preserve them. When
8341 @var{keep-mtime?} is true, keep the modification time of the files in
8342 @var{source} on those of @var{destination}. Write verbose output to the
8346 @deffn {Scheme Procedure} delete-file-recursively @var{dir} @
8347 [#:follow-mounts? #f]
8348 Delete @var{dir} recursively, like @command{rm -rf}, without following
8349 symlinks. Don't follow mount points either, unless @var{follow-mounts?}
8350 is true. Report but ignore errors.
8353 @deffn {Scheme Syntax} substitute* @var{file} @
8354 ((@var{regexp} @var{match-var}@dots{}) @var{body}@dots{}) @dots{}
8355 Substitute @var{regexp} in @var{file} by the string returned by
8356 @var{body}. @var{body} is evaluated with each @var{match-var} bound to
8357 the corresponding positional regexp sub-expression. For example:
8363 (("foo([a-z]+)bar(.*)$" all letters end)
8364 (string-append "baz" letter end)))
8367 Here, anytime a line of @var{file} contains @code{hello}, it is replaced
8368 by @code{good morning}. Anytime a line of @var{file} matches the second
8369 regexp, @code{all} is bound to the complete match, @code{letters} is bound
8370 to the first sub-expression, and @code{end} is bound to the last one.
8372 When one of the @var{match-var} is @code{_}, no variable is bound to the
8373 corresponding match substring.
8375 Alternatively, @var{file} may be a list of file names, in which case
8376 they are all subject to the substitutions.
8378 Be careful about using @code{$} to match the end of a line; by itself it
8379 won't match the terminating newline of a line.
8382 @subsection File Search
8384 @cindex file, searching
8385 This section documents procedures to search and filter files.
8387 @deffn {Scheme Procedure} file-name-predicate @var{regexp}
8388 Return a predicate that returns true when passed a file name whose base
8389 name matches @var{regexp}.
8392 @deffn {Scheme Procedure} find-files @var{dir} [@var{pred}] @
8393 [#:stat lstat] [#:directories? #f] [#:fail-on-error? #f]
8394 Return the lexicographically sorted list of files under @var{dir} for
8395 which @var{pred} returns true. @var{pred} is passed two arguments: the
8396 absolute file name, and its stat buffer; the default predicate always
8397 returns true. @var{pred} can also be a regular expression, in which
8398 case it is equivalent to @code{(file-name-predicate @var{pred})}.
8399 @var{stat} is used to obtain file information; using @code{lstat} means
8400 that symlinks are not followed. If @var{directories?} is true, then
8401 directories will also be included. If @var{fail-on-error?} is true,
8402 raise an exception upon error.
8405 Here are a few examples where we assume that the current directory is
8406 the root of the Guix source tree:
8409 ;; List all the regular files in the current directory.
8411 @result{} ("./.dir-locals.el" "./.gitignore" @dots{})
8413 ;; List all the .scm files under gnu/services.
8414 (find-files "gnu/services" "\\.scm$")
8415 @result{} ("gnu/services/admin.scm" "gnu/services/audio.scm" @dots{})
8417 ;; List ar files in the current directory.
8418 (find-files "." (lambda (file stat) (ar-file? file)))
8419 @result{} ("./libformat.a" "./libstore.a" @dots{})
8422 @deffn {Scheme Procedure} which @var{program}
8423 Return the complete file name for @var{program} as found in
8424 @code{$PATH}, or @code{#f} if @var{program} could not be found.
8427 @subsection Build Phases
8429 @cindex build phases
8430 The @code{(guix build utils)} also contains tools to manipulate build
8431 phases as used by build systems (@pxref{Build Systems}). Build phases
8432 are represented as association lists or ``alists'' (@pxref{Association
8433 Lists,,, guile, GNU Guile Reference Manual}) where each key is a symbol
8434 naming the phase and the associated value is a procedure (@pxref{Build
8437 Guile core and the @code{(srfi srfi-1)} module both provide tools to
8438 manipulate alists. The @code{(guix build utils)} module complements
8439 those with tools written with build phases in mind.
8441 @cindex build phases, modifying
8442 @deffn {Scheme Syntax} modify-phases @var{phases} @var{clause}@dots{}
8443 Modify @var{phases} sequentially as per each @var{clause}, which may
8444 have one of the following forms:
8447 (delete @var{old-phase-name})
8448 (replace @var{old-phase-name} @var{new-phase})
8449 (add-before @var{old-phase-name} @var{new-phase-name} @var{new-phase})
8450 (add-after @var{old-phase-name} @var{new-phase-name} @var{new-phase})
8453 Where every @var{phase-name} above is an expression evaluating to a
8454 symbol, and @var{new-phase} an expression evaluating to a procedure.
8457 The example below is taken from the definition of the @code{grep}
8458 package. It adds a phase to run after the @code{install} phase, called
8459 @code{fix-egrep-and-fgrep}. That phase is a procedure (@code{lambda*}
8460 is for anonymous procedures) that takes a @code{#:outputs} keyword
8461 argument and ignores extra keyword arguments (@pxref{Optional
8462 Arguments,,, guile, GNU Guile Reference Manual}, for more on
8463 @code{lambda*} and optional and keyword arguments.) The phase uses
8464 @code{substitute*} to modify the installed @file{egrep} and @file{fgrep}
8465 scripts so that they refer to @code{grep} by its absolute file name:
8468 (modify-phases %standard-phases
8469 (add-after 'install 'fix-egrep-and-fgrep
8470 ;; Patch 'egrep' and 'fgrep' to execute 'grep' via its
8471 ;; absolute file name instead of searching for it in $PATH.
8472 (lambda* (#:key outputs #:allow-other-keys)
8473 (let* ((out (assoc-ref outputs "out"))
8474 (bin (string-append out "/bin")))
8475 (substitute* (list (string-append bin "/egrep")
8476 (string-append bin "/fgrep"))
8478 (string-append "exec " bin "/grep")))
8482 In the example below, phases are modified in two ways: the standard
8483 @code{configure} phase is deleted, presumably because the package does
8484 not have a @file{configure} script or anything similar, and the default
8485 @code{install} phase is replaced by one that manually copies the
8486 executable files to be installed:
8489 (modify-phases %standard-phases
8490 (delete 'configure) ;no 'configure' script
8492 (lambda* (#:key outputs #:allow-other-keys)
8493 ;; The package's Makefile doesn't provide an "install"
8494 ;; rule so do it by ourselves.
8495 (let ((bin (string-append (assoc-ref outputs "out")
8497 (install-file "footswitch" bin)
8498 (install-file "scythe" bin)
8502 @c TODO: Add more examples.
8511 Conceptually, the @dfn{store} is the place where derivations that have
8512 been built successfully are stored---by default, @file{/gnu/store}.
8513 Sub-directories in the store are referred to as @dfn{store items} or
8514 sometimes @dfn{store paths}. The store has an associated database that
8515 contains information such as the store paths referred to by each store
8516 path, and the list of @emph{valid} store items---results of successful
8517 builds. This database resides in @file{@var{localstatedir}/guix/db},
8518 where @var{localstatedir} is the state directory specified @i{via}
8519 @option{--localstatedir} at configure time, usually @file{/var}.
8521 The store is @emph{always} accessed by the daemon on behalf of its clients
8522 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
8523 connect to the daemon over a Unix-domain socket, send requests to it,
8524 and read the result---these are remote procedure calls, or RPCs.
8527 Users must @emph{never} modify files under @file{/gnu/store} directly.
8528 This would lead to inconsistencies and break the immutability
8529 assumptions of Guix's functional model (@pxref{Introduction}).
8531 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
8532 how to check the integrity of the store and attempt recovery from
8533 accidental modifications.
8536 The @code{(guix store)} module provides procedures to connect to the
8537 daemon, and to perform RPCs. These are described below. By default,
8538 @code{open-connection}, and thus all the @command{guix} commands,
8539 connect to the local daemon or to the URI specified by the
8540 @env{GUIX_DAEMON_SOCKET} environment variable.
8542 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
8543 When set, the value of this variable should be a file name or a URI
8544 designating the daemon endpoint. When it is a file name, it denotes a
8545 Unix-domain socket to connect to. In addition to file names, the
8546 supported URI schemes are:
8551 These are for Unix-domain sockets.
8552 @code{file:///var/guix/daemon-socket/socket} is equivalent to
8553 @file{/var/guix/daemon-socket/socket}.
8556 @cindex daemon, remote access
8557 @cindex remote access to the daemon
8558 @cindex daemon, cluster setup
8559 @cindex clusters, daemon setup
8560 These URIs denote connections over TCP/IP, without encryption nor
8561 authentication of the remote host. The URI must specify the host name
8562 and optionally a port number (by default port 44146 is used):
8565 guix://master.guix.example.org:1234
8568 This setup is suitable on local networks, such as clusters, where only
8569 trusted nodes may connect to the build daemon at
8570 @code{master.guix.example.org}.
8572 The @option{--listen} option of @command{guix-daemon} can be used to
8573 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
8574 @option{--listen}}).
8577 @cindex SSH access to build daemons
8578 These URIs allow you to connect to a remote daemon over SSH. This
8579 feature requires Guile-SSH (@pxref{Requirements}) and a working
8580 @command{guile} binary in @env{PATH} on the destination machine. It
8581 supports public key and GSSAPI authentication. A typical URL might look
8585 ssh://charlie@@guix.example.org:22
8588 As for @command{guix copy}, the usual OpenSSH client configuration files
8589 are honored (@pxref{Invoking guix copy}).
8592 Additional URI schemes may be supported in the future.
8594 @c XXX: Remove this note when the protocol incurs fewer round trips
8595 @c and when (guix derivations) no longer relies on file system access.
8597 The ability to connect to remote build daemons is considered
8598 experimental as of @value{VERSION}. Please get in touch with us to
8599 share any problems or suggestions you may have (@pxref{Contributing}).
8603 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
8604 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
8605 @var{reserve-space?} is true, instruct it to reserve a little bit of
8606 extra space on the file system so that the garbage collector can still
8607 operate should the disk become full. Return a server object.
8609 @var{file} defaults to @code{%default-socket-path}, which is the normal
8610 location given the options that were passed to @command{configure}.
8613 @deffn {Scheme Procedure} close-connection @var{server}
8614 Close the connection to @var{server}.
8617 @defvr {Scheme Variable} current-build-output-port
8618 This variable is bound to a SRFI-39 parameter, which refers to the port
8619 where build and error logs sent by the daemon should be written.
8622 Procedures that make RPCs all take a server object as their first
8625 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
8626 @cindex invalid store items
8627 Return @code{#t} when @var{path} designates a valid store item and
8628 @code{#f} otherwise (an invalid item may exist on disk but still be
8629 invalid, for instance because it is the result of an aborted or failed
8632 A @code{&store-protocol-error} condition is raised if @var{path} is not
8633 prefixed by the store directory (@file{/gnu/store}).
8636 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
8637 Add @var{text} under file @var{name} in the store, and return its store
8638 path. @var{references} is the list of store paths referred to by the
8639 resulting store path.
8642 @deffn {Scheme Procedure} build-derivations @var{store} @var{derivations} @
8644 Build @var{derivations}, a list of @code{<derivation>} objects, @file{.drv}
8645 file names, or derivation/output pairs, using the specified
8646 @var{mode}---@code{(build-mode normal)} by default.
8649 Note that the @code{(guix monads)} module provides a monad as well as
8650 monadic versions of the above procedures, with the goal of making it
8651 more convenient to work with code that accesses the store (@pxref{The
8655 @i{This section is currently incomplete.}
8658 @section Derivations
8661 Low-level build actions and the environment in which they are performed
8662 are represented by @dfn{derivations}. A derivation contains the
8663 following pieces of information:
8667 The outputs of the derivation---derivations produce at least one file or
8668 directory in the store, but may produce more.
8671 @cindex build-time dependencies
8672 @cindex dependencies, build-time
8673 The inputs of the derivations---i.e., its build-time dependencies---which may
8674 be other derivations or plain files in the store (patches, build scripts,
8678 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
8681 The file name of a build script in the store, along with the arguments
8685 A list of environment variables to be defined.
8689 @cindex derivation path
8690 Derivations allow clients of the daemon to communicate build actions to
8691 the store. They exist in two forms: as an in-memory representation,
8692 both on the client- and daemon-side, and as files in the store whose
8693 name end in @file{.drv}---these files are referred to as @dfn{derivation
8694 paths}. Derivations paths can be passed to the @code{build-derivations}
8695 procedure to perform the build actions they prescribe (@pxref{The
8698 @cindex fixed-output derivations
8699 Operations such as file downloads and version-control checkouts for
8700 which the expected content hash is known in advance are modeled as
8701 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
8702 of a fixed-output derivation are independent of its inputs---e.g., a
8703 source code download produces the same result regardless of the download
8704 method and tools being used.
8707 @cindex run-time dependencies
8708 @cindex dependencies, run-time
8709 The outputs of derivations---i.e., the build results---have a set of
8710 @dfn{references}, as reported by the @code{references} RPC or the
8711 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
8712 are the set of run-time dependencies of the build results. References are a
8713 subset of the inputs of the derivation; this subset is automatically computed
8714 by the build daemon by scanning all the files in the outputs.
8716 The @code{(guix derivations)} module provides a representation of
8717 derivations as Scheme objects, along with procedures to create and
8718 otherwise manipulate derivations. The lowest-level primitive to create
8719 a derivation is the @code{derivation} procedure:
8721 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
8722 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
8723 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
8724 [#:system (%current-system)] [#:references-graphs #f] @
8725 [#:allowed-references #f] [#:disallowed-references #f] @
8726 [#:leaked-env-vars #f] [#:local-build? #f] @
8727 [#:substitutable? #t] [#:properties '()]
8728 Build a derivation with the given arguments, and return the resulting
8729 @code{<derivation>} object.
8731 When @var{hash} and @var{hash-algo} are given, a
8732 @dfn{fixed-output derivation} is created---i.e., one whose result is
8733 known in advance, such as a file download. If, in addition,
8734 @var{recursive?} is true, then that fixed output may be an executable
8735 file or a directory and @var{hash} must be the hash of an archive
8736 containing this output.
8738 When @var{references-graphs} is true, it must be a list of file
8739 name/store path pairs. In that case, the reference graph of each store
8740 path is exported in the build environment in the corresponding file, in
8741 a simple text format.
8743 When @var{allowed-references} is true, it must be a list of store items
8744 or outputs that the derivation's output may refer to. Likewise,
8745 @var{disallowed-references}, if true, must be a list of things the
8746 outputs may @emph{not} refer to.
8748 When @var{leaked-env-vars} is true, it must be a list of strings
8749 denoting environment variables that are allowed to ``leak'' from the
8750 daemon's environment to the build environment. This is only applicable
8751 to fixed-output derivations---i.e., when @var{hash} is true. The main
8752 use is to allow variables such as @code{http_proxy} to be passed to
8753 derivations that download files.
8755 When @var{local-build?} is true, declare that the derivation is not a
8756 good candidate for offloading and should rather be built locally
8757 (@pxref{Daemon Offload Setup}). This is the case for small derivations
8758 where the costs of data transfers would outweigh the benefits.
8760 When @var{substitutable?} is false, declare that substitutes of the
8761 derivation's output should not be used (@pxref{Substitutes}). This is
8762 useful, for instance, when building packages that capture details of the
8763 host CPU instruction set.
8765 @var{properties} must be an association list describing ``properties'' of the
8766 derivation. It is kept as-is, uninterpreted, in the derivation.
8770 Here's an example with a shell script as its builder, assuming
8771 @var{store} is an open connection to the daemon, and @var{bash} points
8772 to a Bash executable in the store:
8775 (use-modules (guix utils)
8779 (let ((builder ; add the Bash script to the store
8780 (add-text-to-store store "my-builder.sh"
8781 "echo hello world > $out\n" '())))
8782 (derivation store "foo"
8783 bash `("-e" ,builder)
8784 #:inputs `((,bash) (,builder))
8785 #:env-vars '(("HOME" . "/homeless"))))
8786 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
8789 As can be guessed, this primitive is cumbersome to use directly. A
8790 better approach is to write build scripts in Scheme, of course! The
8791 best course of action for that is to write the build code as a
8792 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
8793 information, @pxref{G-Expressions}.
8795 Once upon a time, @code{gexp->derivation} did not exist and constructing
8796 derivations with build code written in Scheme was achieved with
8797 @code{build-expression->derivation}, documented below. This procedure
8798 is now deprecated in favor of the much nicer @code{gexp->derivation}.
8800 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
8801 @var{name} @var{exp} @
8802 [#:system (%current-system)] [#:inputs '()] @
8803 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
8804 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
8805 [#:references-graphs #f] [#:allowed-references #f] @
8806 [#:disallowed-references #f] @
8807 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
8808 Return a derivation that executes Scheme expression @var{exp} as a
8809 builder for derivation @var{name}. @var{inputs} must be a list of
8810 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
8811 @code{"out"} is assumed. @var{modules} is a list of names of Guile
8812 modules from the current search path to be copied in the store,
8813 compiled, and made available in the load path during the execution of
8814 @var{exp}---e.g., @code{((guix build utils) (guix build
8815 gnu-build-system))}.
8817 @var{exp} is evaluated in an environment where @code{%outputs} is bound
8818 to a list of output/path pairs, and where @code{%build-inputs} is bound
8819 to a list of string/output-path pairs made from @var{inputs}.
8820 Optionally, @var{env-vars} is a list of string pairs specifying the name
8821 and value of environment variables visible to the builder. The builder
8822 terminates by passing the result of @var{exp} to @code{exit}; thus, when
8823 @var{exp} returns @code{#f}, the build is considered to have failed.
8825 @var{exp} is built using @var{guile-for-build} (a derivation). When
8826 @var{guile-for-build} is omitted or is @code{#f}, the value of the
8827 @code{%guile-for-build} fluid is used instead.
8829 See the @code{derivation} procedure for the meaning of
8830 @var{references-graphs}, @var{allowed-references},
8831 @var{disallowed-references}, @var{local-build?}, and
8832 @var{substitutable?}.
8836 Here's an example of a single-output derivation that creates a directory
8837 containing one file:
8840 (let ((builder '(let ((out (assoc-ref %outputs "out")))
8841 (mkdir out) ; create /gnu/store/@dots{}-goo
8842 (call-with-output-file (string-append out "/test")
8844 (display '(hello guix) p))))))
8845 (build-expression->derivation store "goo" builder))
8847 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
8851 @node The Store Monad
8852 @section The Store Monad
8856 The procedures that operate on the store described in the previous
8857 sections all take an open connection to the build daemon as their first
8858 argument. Although the underlying model is functional, they either have
8859 side effects or depend on the current state of the store.
8861 The former is inconvenient: the connection to the build daemon has to be
8862 carried around in all those functions, making it impossible to compose
8863 functions that do not take that parameter with functions that do. The
8864 latter can be problematic: since store operations have side effects
8865 and/or depend on external state, they have to be properly sequenced.
8867 @cindex monadic values
8868 @cindex monadic functions
8869 This is where the @code{(guix monads)} module comes in. This module
8870 provides a framework for working with @dfn{monads}, and a particularly
8871 useful monad for our uses, the @dfn{store monad}. Monads are a
8872 construct that allows two things: associating ``context'' with values
8873 (in our case, the context is the store), and building sequences of
8874 computations (here computations include accesses to the store). Values
8875 in a monad---values that carry this additional context---are called
8876 @dfn{monadic values}; procedures that return such values are called
8877 @dfn{monadic procedures}.
8879 Consider this ``normal'' procedure:
8882 (define (sh-symlink store)
8883 ;; Return a derivation that symlinks the 'bash' executable.
8884 (let* ((drv (package-derivation store bash))
8885 (out (derivation->output-path drv))
8886 (sh (string-append out "/bin/bash")))
8887 (build-expression->derivation store "sh"
8888 `(symlink ,sh %output))))
8891 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
8892 as a monadic function:
8895 (define (sh-symlink)
8896 ;; Same, but return a monadic value.
8897 (mlet %store-monad ((drv (package->derivation bash)))
8898 (gexp->derivation "sh"
8899 #~(symlink (string-append #$drv "/bin/bash")
8903 There are several things to note in the second version: the @code{store}
8904 parameter is now implicit and is ``threaded'' in the calls to the
8905 @code{package->derivation} and @code{gexp->derivation} monadic
8906 procedures, and the monadic value returned by @code{package->derivation}
8907 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
8909 As it turns out, the call to @code{package->derivation} can even be
8910 omitted since it will take place implicitly, as we will see later
8911 (@pxref{G-Expressions}):
8914 (define (sh-symlink)
8915 (gexp->derivation "sh"
8916 #~(symlink (string-append #$bash "/bin/bash")
8921 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
8922 @c for the funny quote.
8923 Calling the monadic @code{sh-symlink} has no effect. As someone once
8924 said, ``you exit a monad like you exit a building on fire: by running''.
8925 So, to exit the monad and get the desired effect, one must use
8926 @code{run-with-store}:
8929 (run-with-store (open-connection) (sh-symlink))
8930 @result{} /gnu/store/...-sh-symlink
8933 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
8934 new ``meta-commands'' to make it easier to deal with monadic procedures:
8935 @code{run-in-store}, and @code{enter-store-monad}. The former is used
8936 to ``run'' a single monadic value through the store:
8939 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
8940 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
8943 The latter enters a recursive REPL, where all the return values are
8944 automatically run through the store:
8947 scheme@@(guile-user)> ,enter-store-monad
8948 store-monad@@(guile-user) [1]> (package->derivation hello)
8949 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
8950 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
8951 $3 = "/gnu/store/@dots{}-foo"
8952 store-monad@@(guile-user) [1]> ,q
8953 scheme@@(guile-user)>
8957 Note that non-monadic values cannot be returned in the
8958 @code{store-monad} REPL.
8960 The main syntactic forms to deal with monads in general are provided by
8961 the @code{(guix monads)} module and are described below.
8963 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
8964 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
8968 @deffn {Scheme Syntax} return @var{val}
8969 Return a monadic value that encapsulates @var{val}.
8972 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
8973 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
8974 procedures @var{mproc}@dots{}@footnote{This operation is commonly
8975 referred to as ``bind'', but that name denotes an unrelated procedure in
8976 Guile. Thus we use this somewhat cryptic symbol inherited from the
8977 Haskell language.}. There can be one @var{mproc} or several of them, as
8982 (with-monad %state-monad
8984 (lambda (x) (return (+ 1 x)))
8985 (lambda (x) (return (* 2 x)))))
8989 @result{} some-state
8993 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
8995 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
8997 Bind the variables @var{var} to the monadic values @var{mval} in
8998 @var{body}, which is a sequence of expressions. As with the bind
8999 operator, this can be thought of as ``unpacking'' the raw, non-monadic
9000 value ``contained'' in @var{mval} and making @var{var} refer to that
9001 raw, non-monadic value within the scope of the @var{body}. The form
9002 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
9003 @var{val}, as per @code{let}. The binding operations occur in sequence
9004 from left to right. The last expression of @var{body} must be a monadic
9005 expression, and its result will become the result of the @code{mlet} or
9006 @code{mlet*} when run in the @var{monad}.
9008 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
9009 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
9012 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
9013 Bind @var{mexp} and the following monadic expressions in sequence,
9014 returning the result of the last expression. Every expression in the
9015 sequence must be a monadic expression.
9017 This is akin to @code{mlet}, except that the return values of the
9018 monadic expressions are ignored. In that sense, it is analogous to
9019 @code{begin}, but applied to monadic expressions.
9022 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
9023 When @var{condition} is true, evaluate the sequence of monadic
9024 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
9025 @var{condition} is false, return @code{*unspecified*} in the current
9026 monad. Every expression in the sequence must be a monadic expression.
9029 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
9030 When @var{condition} is false, evaluate the sequence of monadic
9031 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
9032 @var{condition} is true, return @code{*unspecified*} in the current
9033 monad. Every expression in the sequence must be a monadic expression.
9037 The @code{(guix monads)} module provides the @dfn{state monad}, which
9038 allows an additional value---the state---to be @emph{threaded} through
9039 monadic procedure calls.
9041 @defvr {Scheme Variable} %state-monad
9042 The state monad. Procedures in the state monad can access and change
9043 the state that is threaded.
9045 Consider the example below. The @code{square} procedure returns a value
9046 in the state monad. It returns the square of its argument, but also
9047 increments the current state value:
9051 (mlet %state-monad ((count (current-state)))
9052 (mbegin %state-monad
9053 (set-current-state (+ 1 count))
9056 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
9061 When ``run'' through @code{%state-monad}, we obtain that additional state
9062 value, which is the number of @code{square} calls.
9065 @deffn {Monadic Procedure} current-state
9066 Return the current state as a monadic value.
9069 @deffn {Monadic Procedure} set-current-state @var{value}
9070 Set the current state to @var{value} and return the previous state as a
9074 @deffn {Monadic Procedure} state-push @var{value}
9075 Push @var{value} to the current state, which is assumed to be a list,
9076 and return the previous state as a monadic value.
9079 @deffn {Monadic Procedure} state-pop
9080 Pop a value from the current state and return it as a monadic value.
9081 The state is assumed to be a list.
9084 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
9085 Run monadic value @var{mval} starting with @var{state} as the initial
9086 state. Return two values: the resulting value, and the resulting state.
9089 The main interface to the store monad, provided by the @code{(guix
9090 store)} module, is as follows.
9092 @defvr {Scheme Variable} %store-monad
9093 The store monad---an alias for @code{%state-monad}.
9095 Values in the store monad encapsulate accesses to the store. When its
9096 effect is needed, a value of the store monad must be ``evaluated'' by
9097 passing it to the @code{run-with-store} procedure (see below).
9100 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
9101 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
9102 open store connection.
9105 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
9106 Return as a monadic value the absolute file name in the store of the file
9107 containing @var{text}, a string. @var{references} is a list of store items that the
9108 resulting text file refers to; it defaults to the empty list.
9111 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
9112 Return as a monadic value the absolute file name in the store of the file
9113 containing @var{data}, a bytevector. @var{references} is a list of store
9114 items that the resulting binary file refers to; it defaults to the empty list.
9117 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
9118 [#:recursive? #t] [#:select? (const #t)]
9119 Return the name of @var{file} once interned in the store. Use
9120 @var{name} as its store name, or the basename of @var{file} if
9121 @var{name} is omitted.
9123 When @var{recursive?} is true, the contents of @var{file} are added
9124 recursively; if @var{file} designates a flat file and @var{recursive?}
9125 is true, its contents are added, and its permission bits are kept.
9127 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
9128 @var{stat})} for each directory entry, where @var{file} is the entry's
9129 absolute file name and @var{stat} is the result of @code{lstat}; exclude
9130 entries for which @var{select?} does not return true.
9132 The example below adds a file to the store, under two different names:
9135 (run-with-store (open-connection)
9136 (mlet %store-monad ((a (interned-file "README"))
9137 (b (interned-file "README" "LEGU-MIN")))
9138 (return (list a b))))
9140 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
9145 The @code{(guix packages)} module exports the following package-related
9148 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
9149 [#:system (%current-system)] [#:target #f] @
9152 value in the absolute file name of @var{file} within the @var{output}
9153 directory of @var{package}. When @var{file} is omitted, return the name
9154 of the @var{output} directory of @var{package}. When @var{target} is
9155 true, use it as a cross-compilation target triplet.
9157 Note that this procedure does @emph{not} build @var{package}. Thus, the
9158 result might or might not designate an existing file. We recommend not
9159 using this procedure unless you know what you are doing.
9162 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
9163 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
9164 @var{target} [@var{system}]
9165 Monadic version of @code{package-derivation} and
9166 @code{package-cross-derivation} (@pxref{Defining Packages}).
9171 @section G-Expressions
9173 @cindex G-expression
9174 @cindex build code quoting
9175 So we have ``derivations'', which represent a sequence of build actions
9176 to be performed to produce an item in the store (@pxref{Derivations}).
9177 These build actions are performed when asking the daemon to actually
9178 build the derivations; they are run by the daemon in a container
9179 (@pxref{Invoking guix-daemon}).
9181 @cindex code staging
9182 @cindex staging, of code
9183 @cindex strata of code
9184 It should come as no surprise that we like to write these build actions
9185 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
9186 code@footnote{The term @dfn{stratum} in this context was coined by
9187 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
9188 Kiselyov, who has written insightful
9189 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
9190 on this topic}, refers to this kind of code generation as
9191 @dfn{staging}.}: the ``host code''---code that defines packages, talks
9192 to the daemon, etc.---and the ``build code''---code that actually
9193 performs build actions, such as making directories, invoking
9194 @command{make}, and so on (@pxref{Build Phases}).
9196 To describe a derivation and its build actions, one typically needs to
9197 embed build code inside host code. It boils down to manipulating build
9198 code as data, and the homoiconicity of Scheme---code has a direct
9199 representation as data---comes in handy for that. But we need more than
9200 the normal @code{quasiquote} mechanism in Scheme to construct build
9203 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
9204 S-expressions adapted to build expressions. G-expressions, or
9205 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
9206 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
9207 @code{#$}, and @code{#$@@}), which are comparable to
9208 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
9209 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
9210 GNU Guile Reference Manual}). However, there are major differences:
9214 Gexps are meant to be written to a file and run or manipulated by other
9218 When a high-level object such as a package or derivation is unquoted
9219 inside a gexp, the result is as if its output file name had been
9223 Gexps carry information about the packages or derivations they refer to,
9224 and these dependencies are automatically added as inputs to the build
9225 processes that use them.
9228 @cindex lowering, of high-level objects in gexps
9229 This mechanism is not limited to package and derivation
9230 objects: @dfn{compilers} able to ``lower'' other high-level objects to
9231 derivations or files in the store can be defined,
9232 such that these objects can also be inserted
9233 into gexps. For example, a useful type of high-level objects that can be
9234 inserted in a gexp is ``file-like objects'', which make it easy to
9235 add files to the store and to refer to them in
9236 derivations and such (see @code{local-file} and @code{plain-file}
9239 To illustrate the idea, here is an example of a gexp:
9246 (symlink (string-append #$coreutils "/bin/ls")
9250 This gexp can be passed to @code{gexp->derivation}; we obtain a
9251 derivation that builds a directory containing exactly one symlink to
9252 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
9255 (gexp->derivation "the-thing" build-exp)
9258 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
9259 substituted to the reference to the @var{coreutils} package in the
9260 actual build code, and @var{coreutils} is automatically made an input to
9261 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
9262 output)}) is replaced by a string containing the directory name of the
9263 output of the derivation.
9265 @cindex cross compilation
9266 In a cross-compilation context, it is useful to distinguish between
9267 references to the @emph{native} build of a package---that can run on the
9268 host---versus references to cross builds of a package. To that end, the
9269 @code{#+} plays the same role as @code{#$}, but is a reference to a
9270 native package build:
9273 (gexp->derivation "vi"
9276 (mkdir (string-append #$output "/bin"))
9277 (system* (string-append #+coreutils "/bin/ln")
9279 (string-append #$emacs "/bin/emacs")
9280 (string-append #$output "/bin/vi")))
9281 #:target "aarch64-linux-gnu")
9285 In the example above, the native build of @var{coreutils} is used, so
9286 that @command{ln} can actually run on the host; but then the
9287 cross-compiled build of @var{emacs} is referenced.
9289 @cindex imported modules, for gexps
9290 @findex with-imported-modules
9291 Another gexp feature is @dfn{imported modules}: sometimes you want to be
9292 able to use certain Guile modules from the ``host environment'' in the
9293 gexp, so those modules should be imported in the ``build environment''.
9294 The @code{with-imported-modules} form allows you to express that:
9297 (let ((build (with-imported-modules '((guix build utils))
9299 (use-modules (guix build utils))
9300 (mkdir-p (string-append #$output "/bin"))))))
9301 (gexp->derivation "empty-dir"
9304 (display "success!\n")
9309 In this example, the @code{(guix build utils)} module is automatically
9310 pulled into the isolated build environment of our gexp, such that
9311 @code{(use-modules (guix build utils))} works as expected.
9313 @cindex module closure
9314 @findex source-module-closure
9315 Usually you want the @emph{closure} of the module to be imported---i.e.,
9316 the module itself and all the modules it depends on---rather than just
9317 the module; failing to do that, attempts to use the module will fail
9318 because of missing dependent modules. The @code{source-module-closure}
9319 procedure computes the closure of a module by looking at its source file
9320 headers, which comes in handy in this case:
9323 (use-modules (guix modules)) ;for 'source-module-closure'
9325 (with-imported-modules (source-module-closure
9326 '((guix build utils)
9328 (gexp->derivation "something-with-vms"
9330 (use-modules (guix build utils)
9335 @cindex extensions, for gexps
9336 @findex with-extensions
9337 In the same vein, sometimes you want to import not just pure-Scheme
9338 modules, but also ``extensions'' such as Guile bindings to C libraries
9339 or other ``full-blown'' packages. Say you need the @code{guile-json}
9340 package available on the build side, here's how you would do it:
9343 (use-modules (gnu packages guile)) ;for 'guile-json'
9345 (with-extensions (list guile-json)
9346 (gexp->derivation "something-with-json"
9348 (use-modules (json))
9352 The syntactic form to construct gexps is summarized below.
9354 @deffn {Scheme Syntax} #~@var{exp}
9355 @deffnx {Scheme Syntax} (gexp @var{exp})
9356 Return a G-expression containing @var{exp}. @var{exp} may contain one
9357 or more of the following forms:
9361 @itemx (ungexp @var{obj})
9362 Introduce a reference to @var{obj}. @var{obj} may have one of the
9363 supported types, for example a package or a
9364 derivation, in which case the @code{ungexp} form is replaced by its
9365 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
9367 If @var{obj} is a list, it is traversed and references to supported
9368 objects are substituted similarly.
9370 If @var{obj} is another gexp, its contents are inserted and its
9371 dependencies are added to those of the containing gexp.
9373 If @var{obj} is another kind of object, it is inserted as is.
9375 @item #$@var{obj}:@var{output}
9376 @itemx (ungexp @var{obj} @var{output})
9377 This is like the form above, but referring explicitly to the
9378 @var{output} of @var{obj}---this is useful when @var{obj} produces
9379 multiple outputs (@pxref{Packages with Multiple Outputs}).
9382 @itemx #+@var{obj}:output
9383 @itemx (ungexp-native @var{obj})
9384 @itemx (ungexp-native @var{obj} @var{output})
9385 Same as @code{ungexp}, but produces a reference to the @emph{native}
9386 build of @var{obj} when used in a cross compilation context.
9388 @item #$output[:@var{output}]
9389 @itemx (ungexp output [@var{output}])
9390 Insert a reference to derivation output @var{output}, or to the main
9391 output when @var{output} is omitted.
9393 This only makes sense for gexps passed to @code{gexp->derivation}.
9396 @itemx (ungexp-splicing @var{lst})
9397 Like the above, but splices the contents of @var{lst} inside the
9401 @itemx (ungexp-native-splicing @var{lst})
9402 Like the above, but refers to native builds of the objects listed in
9407 G-expressions created by @code{gexp} or @code{#~} are run-time objects
9408 of the @code{gexp?} type (see below).
9411 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
9412 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
9413 in their execution environment.
9415 Each item in @var{modules} can be the name of a module, such as
9416 @code{(guix build utils)}, or it can be a module name, followed by an
9417 arrow, followed by a file-like object:
9420 `((guix build utils)
9422 ((guix config) => ,(scheme-file "config.scm"
9423 #~(define-module @dots{}))))
9427 In the example above, the first two modules are taken from the search
9428 path, and the last one is created from the given file-like object.
9430 This form has @emph{lexical} scope: it has an effect on the gexps
9431 directly defined in @var{body}@dots{}, but not on those defined, say, in
9432 procedures called from @var{body}@dots{}.
9435 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
9436 Mark the gexps defined in @var{body}@dots{} as requiring
9437 @var{extensions} in their build and execution environment.
9438 @var{extensions} is typically a list of package objects such as those
9439 defined in the @code{(gnu packages guile)} module.
9441 Concretely, the packages listed in @var{extensions} are added to the
9442 load path while compiling imported modules in @var{body}@dots{}; they
9443 are also added to the load path of the gexp returned by
9447 @deffn {Scheme Procedure} gexp? @var{obj}
9448 Return @code{#t} if @var{obj} is a G-expression.
9451 G-expressions are meant to be written to disk, either as code building
9452 some derivation, or as plain files in the store. The monadic procedures
9453 below allow you to do that (@pxref{The Store Monad}, for more
9454 information about monads).
9456 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
9457 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
9458 [#:hash #f] [#:hash-algo #f] @
9459 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
9460 [#:module-path @code{%load-path}] @
9461 [#:effective-version "2.2"] @
9462 [#:references-graphs #f] [#:allowed-references #f] @
9463 [#:disallowed-references #f] @
9464 [#:leaked-env-vars #f] @
9465 [#:script-name (string-append @var{name} "-builder")] @
9466 [#:deprecation-warnings #f] @
9467 [#:local-build? #f] [#:substitutable? #t] @
9468 [#:properties '()] [#:guile-for-build #f]
9469 Return a derivation @var{name} that runs @var{exp} (a gexp) with
9470 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
9471 stored in a file called @var{script-name}. When @var{target} is true,
9472 it is used as the cross-compilation target triplet for packages referred
9475 @var{modules} is deprecated in favor of @code{with-imported-modules}.
9477 make @var{modules} available in the evaluation context of @var{exp};
9478 @var{modules} is a list of names of Guile modules searched in
9479 @var{module-path} to be copied in the store, compiled, and made available in
9480 the load path during the execution of @var{exp}---e.g., @code{((guix
9481 build utils) (guix build gnu-build-system))}.
9483 @var{effective-version} determines the string to use when adding extensions of
9484 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
9486 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
9489 When @var{references-graphs} is true, it must be a list of tuples of one of the
9493 (@var{file-name} @var{package})
9494 (@var{file-name} @var{package} @var{output})
9495 (@var{file-name} @var{derivation})
9496 (@var{file-name} @var{derivation} @var{output})
9497 (@var{file-name} @var{store-item})
9500 The right-hand-side of each element of @var{references-graphs} is automatically made
9501 an input of the build process of @var{exp}. In the build environment, each
9502 @var{file-name} contains the reference graph of the corresponding item, in a simple
9505 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
9506 In the latter case, the list denotes store items that the result is allowed to
9507 refer to. Any reference to another store item will lead to a build error.
9508 Similarly for @var{disallowed-references}, which can list items that must not be
9509 referenced by the outputs.
9511 @var{deprecation-warnings} determines whether to show deprecation warnings while
9512 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
9514 The other arguments are as for @code{derivation} (@pxref{Derivations}).
9517 @cindex file-like objects
9518 The @code{local-file}, @code{plain-file}, @code{computed-file},
9519 @code{program-file}, and @code{scheme-file} procedures below return
9520 @dfn{file-like objects}. That is, when unquoted in a G-expression,
9521 these objects lead to a file in the store. Consider this G-expression:
9524 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
9525 #$(local-file "/tmp/my-nscd.conf"))
9528 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
9529 to the store. Once expanded, for instance @i{via}
9530 @code{gexp->derivation}, the G-expression refers to that copy under
9531 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
9532 does not have any effect on what the G-expression does.
9533 @code{plain-file} can be used similarly; it differs in that the file
9534 content is directly passed as a string.
9536 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
9537 [#:recursive? #f] [#:select? (const #t)]
9538 Return an object representing local file @var{file} to add to the store;
9539 this object can be used in a gexp. If @var{file} is a literal string
9540 denoting a relative file name, it is looked up relative to the source
9541 file where it appears; if @var{file} is not a literal string, it is
9542 looked up relative to the current working directory at run time.
9543 @var{file} will be added to the store under @var{name}--by default the
9544 base name of @var{file}.
9546 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
9547 designates a flat file and @var{recursive?} is true, its contents are added, and its
9548 permission bits are kept.
9550 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
9551 @var{stat})} for each directory entry, where @var{file} is the entry's
9552 absolute file name and @var{stat} is the result of @code{lstat}; exclude
9553 entries for which @var{select?} does not return true.
9555 This is the declarative counterpart of the @code{interned-file} monadic
9556 procedure (@pxref{The Store Monad, @code{interned-file}}).
9559 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
9560 Return an object representing a text file called @var{name} with the given
9561 @var{content} (a string or a bytevector) to be added to the store.
9563 This is the declarative counterpart of @code{text-file}.
9566 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
9569 Return an object representing the store item @var{name}, a file or
9570 directory computed by @var{gexp}. When @var{local-build?} is true (the
9571 default), the derivation is built locally. @var{options} is a list of
9572 additional arguments to pass to @code{gexp->derivation}.
9574 This is the declarative counterpart of @code{gexp->derivation}.
9577 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
9578 [#:guile (default-guile)] [#:module-path %load-path] @
9579 [#:system (%current-system)] [#:target #f]
9580 Return an executable script @var{name} that runs @var{exp} using
9581 @var{guile}, with @var{exp}'s imported modules in its search path.
9582 Look up @var{exp}'s modules in @var{module-path}.
9584 The example below builds a script that simply invokes the @command{ls}
9588 (use-modules (guix gexp) (gnu packages base))
9590 (gexp->script "list-files"
9591 #~(execl #$(file-append coreutils "/bin/ls")
9595 When ``running'' it through the store (@pxref{The Store Monad,
9596 @code{run-with-store}}), we obtain a derivation that produces an
9597 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
9600 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
9602 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
9606 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
9607 [#:guile #f] [#:module-path %load-path]
9608 Return an object representing the executable store item @var{name} that
9609 runs @var{gexp}. @var{guile} is the Guile package used to execute that
9610 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
9612 This is the declarative counterpart of @code{gexp->script}.
9615 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
9616 [#:set-load-path? #t] [#:module-path %load-path] @
9618 [#:guile (default-guile)]
9619 Return a derivation that builds a file @var{name} containing @var{exp}.
9620 When @var{splice?} is true, @var{exp} is considered to be a list of
9621 expressions that will be spliced in the resulting file.
9623 When @var{set-load-path?} is true, emit code in the resulting file to
9624 set @code{%load-path} and @code{%load-compiled-path} to honor
9625 @var{exp}'s imported modules. Look up @var{exp}'s modules in
9628 The resulting file holds references to all the dependencies of @var{exp}
9629 or a subset thereof.
9632 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} @
9633 [#:splice? #f] [#:set-load-path? #t]
9634 Return an object representing the Scheme file @var{name} that contains
9637 This is the declarative counterpart of @code{gexp->file}.
9640 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
9641 Return as a monadic value a derivation that builds a text file
9642 containing all of @var{text}. @var{text} may list, in addition to
9643 strings, objects of any type that can be used in a gexp: packages,
9644 derivations, local file objects, etc. The resulting store file holds
9645 references to all these.
9647 This variant should be preferred over @code{text-file} anytime the file
9648 to create will reference items from the store. This is typically the
9649 case when building a configuration file that embeds store file names,
9653 (define (profile.sh)
9654 ;; Return the name of a shell script in the store that
9655 ;; initializes the 'PATH' environment variable.
9656 (text-file* "profile.sh"
9657 "export PATH=" coreutils "/bin:"
9658 grep "/bin:" sed "/bin\n"))
9661 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
9662 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
9663 preventing them from being garbage-collected during its lifetime.
9666 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
9667 Return an object representing store file @var{name} containing
9668 @var{text}. @var{text} is a sequence of strings and file-like objects,
9672 (mixed-text-file "profile"
9673 "export PATH=" coreutils "/bin:" grep "/bin")
9676 This is the declarative counterpart of @code{text-file*}.
9679 @deffn {Scheme Procedure} file-union @var{name} @var{files}
9680 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
9681 Each item in @var{files} must be a two-element list where the first element is the
9682 file name to use in the new directory, and the second element is a gexp
9683 denoting the target file. Here's an example:
9687 `(("hosts" ,(plain-file "hosts"
9688 "127.0.0.1 localhost"))
9689 ("bashrc" ,(plain-file "bashrc"
9690 "alias ls='ls --color=auto'"))))
9693 This yields an @code{etc} directory containing these two files.
9696 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
9697 Return a directory that is the union of @var{things}, where @var{things} is a list of
9698 file-like objects denoting directories. For example:
9701 (directory-union "guile+emacs" (list guile emacs))
9704 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
9707 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
9708 Return a file-like object that expands to the concatenation of @var{obj}
9709 and @var{suffix}, where @var{obj} is a lowerable object and each
9710 @var{suffix} is a string.
9712 As an example, consider this gexp:
9715 (gexp->script "run-uname"
9716 #~(system* #$(file-append coreutils
9720 The same effect could be achieved with:
9723 (gexp->script "run-uname"
9724 #~(system* (string-append #$coreutils
9728 There is one difference though: in the @code{file-append} case, the
9729 resulting script contains the absolute file name as a string, whereas in
9730 the second case, the resulting script contains a @code{(string-append
9731 @dots{})} expression to construct the file name @emph{at run time}.
9734 @deffn {Scheme Syntax} let-system @var{system} @var{body}@dots{}
9735 @deffnx {Scheme Syntax} let-system (@var{system} @var{target}) @var{body}@dots{}
9736 Bind @var{system} to the currently targeted system---e.g.,
9737 @code{"x86_64-linux"}---within @var{body}.
9739 In the second case, additionally bind @var{target} to the current
9740 cross-compilation target---a GNU triplet such as
9741 @code{"arm-linux-gnueabihf"}---or @code{#f} if we are not
9744 @code{let-system} is useful in the occasional case where the object
9745 spliced into the gexp depends on the target system, as in this example:
9749 #+(let-system system
9750 (cond ((string-prefix? "armhf-" system)
9751 (file-append qemu "/bin/qemu-system-arm"))
9752 ((string-prefix? "x86_64-" system)
9753 (file-append qemu "/bin/qemu-system-x86_64"))
9756 "-net" "user" #$image)
9760 @deffn {Scheme Syntax} with-parameters ((@var{parameter} @var{value}) @dots{}) @var{exp}
9761 This macro is similar to the @code{parameterize} form for
9762 dynamically-bound @dfn{parameters} (@pxref{Parameters,,, guile, GNU
9763 Guile Reference Manual}). The key difference is that it takes effect
9764 when the file-like object returned by @var{exp} is lowered to a
9765 derivation or store item.
9767 A typical use of @code{with-parameters} is to force the system in effect
9771 (with-parameters ((%current-system "i686-linux"))
9775 The example above returns an object that corresponds to the i686 build
9776 of Coreutils, regardless of the current value of @code{%current-system}.
9780 Of course, in addition to gexps embedded in ``host'' code, there are
9781 also modules containing build tools. To make it clear that they are
9782 meant to be used in the build stratum, these modules are kept in the
9783 @code{(guix build @dots{})} name space.
9785 @cindex lowering, of high-level objects in gexps
9786 Internally, high-level objects are @dfn{lowered}, using their compiler,
9787 to either derivations or store items. For instance, lowering a package
9788 yields a derivation, and lowering a @code{plain-file} yields a store
9789 item. This is achieved using the @code{lower-object} monadic procedure.
9791 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
9793 Return as a value in @code{%store-monad} the derivation or store item
9794 corresponding to @var{obj} for @var{system}, cross-compiling for
9795 @var{target} if @var{target} is true. @var{obj} must be an object that
9796 has an associated gexp compiler, such as a @code{<package>}.
9799 @node Invoking guix repl
9800 @section Invoking @command{guix repl}
9802 @cindex REPL, read-eval-print loop, script
9803 The @command{guix repl} command makes it easier to program Guix in Guile
9804 by launching a Guile @dfn{read-eval-print loop} (REPL) for interactive
9805 programming (@pxref{Using Guile Interactively,,, guile,
9806 GNU Guile Reference Manual}), or by running Guile scripts
9807 (@pxref{Running Guile Scripts,,, guile,
9808 GNU Guile Reference Manual}).
9809 Compared to just launching the @command{guile}
9810 command, @command{guix repl} guarantees that all the Guix modules and all its
9811 dependencies are available in the search path.
9813 The general syntax is:
9816 guix repl @var{options} [@var{file} @var{args}]
9819 When a @var{file} argument is provided, @var{file} is
9820 executed as a Guile scripts:
9823 guix repl my-script.scm
9826 To pass arguments to the script, use @code{--} to prevent them from
9827 being interpreted as arguments to @command{guix repl} itself:
9830 guix repl -- my-script.scm --input=foo.txt
9833 To make a script executable directly from the shell, using the guix
9834 executable that is on the user's search path, add the following two
9835 lines at the top of the script:
9838 @code{#!/usr/bin/env -S guix repl --}
9842 Without a file name argument, a Guile REPL is started:
9846 scheme@@(guile-user)> ,use (gnu packages base)
9847 scheme@@(guile-user)> coreutils
9848 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
9852 In addition, @command{guix repl} implements a simple machine-readable REPL
9853 protocol for use by @code{(guix inferior)}, a facility to interact with
9854 @dfn{inferiors}, separate processes running a potentially different revision
9857 The available options are as follows:
9860 @item --type=@var{type}
9861 @itemx -t @var{type}
9862 Start a REPL of the given @var{TYPE}, which can be one of the following:
9866 This is default, and it spawns a standard full-featured Guile REPL.
9868 Spawn a REPL that uses the machine-readable protocol. This is the protocol
9869 that the @code{(guix inferior)} module speaks.
9872 @item --listen=@var{endpoint}
9873 By default, @command{guix repl} reads from standard input and writes to
9874 standard output. When this option is passed, it will instead listen for
9875 connections on @var{endpoint}. Here are examples of valid options:
9878 @item --listen=tcp:37146
9879 Accept connections on localhost on port 37146.
9881 @item --listen=unix:/tmp/socket
9882 Accept connections on the Unix-domain socket @file{/tmp/socket}.
9885 @item --load-path=@var{directory}
9886 @itemx -L @var{directory}
9887 Add @var{directory} to the front of the package module search path
9888 (@pxref{Package Modules}).
9890 This allows users to define their own packages and make them visible to
9894 Inhibit loading of the @file{~/.guile} file. By default, that
9895 configuration file is loaded when spawning a @code{guile} REPL.
9898 @c *********************************************************************
9902 This section describes Guix command-line utilities. Some of them are
9903 primarily targeted at developers and users who write new package
9904 definitions, while others are more generally useful. They complement
9905 the Scheme programming interface of Guix in a convenient way.
9908 * Invoking guix build:: Building packages from the command line.
9909 * Invoking guix edit:: Editing package definitions.
9910 * Invoking guix download:: Downloading a file and printing its hash.
9911 * Invoking guix hash:: Computing the cryptographic hash of a file.
9912 * Invoking guix import:: Importing package definitions.
9913 * Invoking guix refresh:: Updating package definitions.
9914 * Invoking guix lint:: Finding errors in package definitions.
9915 * Invoking guix size:: Profiling disk usage.
9916 * Invoking guix graph:: Visualizing the graph of packages.
9917 * Invoking guix publish:: Sharing substitutes.
9918 * Invoking guix challenge:: Challenging substitute servers.
9919 * Invoking guix copy:: Copying to and from a remote store.
9920 * Invoking guix container:: Process isolation.
9921 * Invoking guix weather:: Assessing substitute availability.
9922 * Invoking guix processes:: Listing client processes.
9925 @node Invoking guix build
9926 @section Invoking @command{guix build}
9928 @cindex package building
9929 @cindex @command{guix build}
9930 The @command{guix build} command builds packages or derivations and
9931 their dependencies, and prints the resulting store paths. Note that it
9932 does not modify the user's profile---this is the job of the
9933 @command{guix package} command (@pxref{Invoking guix package}). Thus,
9934 it is mainly useful for distribution developers.
9936 The general syntax is:
9939 guix build @var{options} @var{package-or-derivation}@dots{}
9942 As an example, the following command builds the latest versions of Emacs
9943 and of Guile, displays their build logs, and finally displays the
9944 resulting directories:
9947 guix build emacs guile
9950 Similarly, the following command builds all the available packages:
9953 guix build --quiet --keep-going \
9954 `guix package -A | cut -f1,2 --output-delimiter=@@`
9957 @var{package-or-derivation} may be either the name of a package found in
9958 the software distribution such as @code{coreutils} or
9959 @code{coreutils@@8.20}, or a derivation such as
9960 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
9961 package with the corresponding name (and optionally version) is searched
9962 for among the GNU distribution modules (@pxref{Package Modules}).
9964 Alternatively, the @option{--expression} option may be used to specify a
9965 Scheme expression that evaluates to a package; this is useful when
9966 disambiguating among several same-named packages or package variants is
9969 There may be zero or more @var{options}. The available options are
9970 described in the subsections below.
9973 * Common Build Options:: Build options for most commands.
9974 * Package Transformation Options:: Creating variants of packages.
9975 * Additional Build Options:: Options specific to 'guix build'.
9976 * Debugging Build Failures:: Real life packaging experience.
9979 @node Common Build Options
9980 @subsection Common Build Options
9982 A number of options that control the build process are common to
9983 @command{guix build} and other commands that can spawn builds, such as
9984 @command{guix package} or @command{guix archive}. These are the
9989 @item --load-path=@var{directory}
9990 @itemx -L @var{directory}
9991 Add @var{directory} to the front of the package module search path
9992 (@pxref{Package Modules}).
9994 This allows users to define their own packages and make them visible to
9995 the command-line tools.
9999 Keep the build tree of failed builds. Thus, if a build fails, its build
10000 tree is kept under @file{/tmp}, in a directory whose name is shown at
10001 the end of the build log. This is useful when debugging build issues.
10002 @xref{Debugging Build Failures}, for tips and tricks on how to debug
10005 This option implies @option{--no-offload}, and it has no effect when
10006 connecting to a remote daemon with a @code{guix://} URI (@pxref{The
10007 Store, the @env{GUIX_DAEMON_SOCKET} variable}).
10011 Keep going when some of the derivations fail to build; return only once
10012 all the builds have either completed or failed.
10014 The default behavior is to stop as soon as one of the specified
10015 derivations has failed.
10019 Do not build the derivations.
10021 @anchor{fallback-option}
10023 When substituting a pre-built binary fails, fall back to building
10024 packages locally (@pxref{Substitution Failure}).
10026 @item --substitute-urls=@var{urls}
10027 @anchor{client-substitute-urls}
10028 Consider @var{urls} the whitespace-separated list of substitute source
10029 URLs, overriding the default list of URLs of @command{guix-daemon}
10030 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
10032 This means that substitutes may be downloaded from @var{urls}, provided
10033 they are signed by a key authorized by the system administrator
10034 (@pxref{Substitutes}).
10036 When @var{urls} is the empty string, substitutes are effectively
10039 @item --no-substitutes
10040 Do not use substitutes for build products. That is, always build things
10041 locally instead of allowing downloads of pre-built binaries
10042 (@pxref{Substitutes}).
10045 Do not ``graft'' packages. In practice, this means that package updates
10046 available as grafts are not applied. @xref{Security Updates}, for more
10047 information on grafts.
10049 @item --rounds=@var{n}
10050 Build each derivation @var{n} times in a row, and raise an error if
10051 consecutive build results are not bit-for-bit identical.
10053 This is a useful way to detect non-deterministic builds processes.
10054 Non-deterministic build processes are a problem because they make it
10055 practically impossible for users to @emph{verify} whether third-party
10056 binaries are genuine. @xref{Invoking guix challenge}, for more.
10058 When used in conjunction with @option{--keep-failed}, the differing
10059 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
10060 This makes it easy to look for differences between the two results.
10063 Do not use offload builds to other machines (@pxref{Daemon Offload
10064 Setup}). That is, always build things locally instead of offloading
10065 builds to remote machines.
10067 @item --max-silent-time=@var{seconds}
10068 When the build or substitution process remains silent for more than
10069 @var{seconds}, terminate it and report a build failure.
10071 By default, the daemon's setting is honored (@pxref{Invoking
10072 guix-daemon, @option{--max-silent-time}}).
10074 @item --timeout=@var{seconds}
10075 Likewise, when the build or substitution process lasts for more than
10076 @var{seconds}, terminate it and report a build failure.
10078 By default, the daemon's setting is honored (@pxref{Invoking
10079 guix-daemon, @option{--timeout}}).
10081 @c Note: This option is actually not part of %standard-build-options but
10082 @c most programs honor it.
10083 @cindex verbosity, of the command-line tools
10084 @cindex build logs, verbosity
10085 @item -v @var{level}
10086 @itemx --verbosity=@var{level}
10087 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
10088 output is produced, 1 is for quiet output, and 2 shows all the build log
10089 output on standard error.
10091 @item --cores=@var{n}
10093 Allow the use of up to @var{n} CPU cores for the build. The special
10094 value @code{0} means to use as many CPU cores as available.
10096 @item --max-jobs=@var{n}
10098 Allow at most @var{n} build jobs in parallel. @xref{Invoking
10099 guix-daemon, @option{--max-jobs}}, for details about this option and the
10100 equivalent @command{guix-daemon} option.
10102 @item --debug=@var{level}
10103 Produce debugging output coming from the build daemon. @var{level} must be an
10104 integer between 0 and 5; higher means more verbose output. Setting a level of
10105 4 or more may be helpful when debugging setup issues with the build daemon.
10109 Behind the scenes, @command{guix build} is essentially an interface to
10110 the @code{package-derivation} procedure of the @code{(guix packages)}
10111 module, and to the @code{build-derivations} procedure of the @code{(guix
10112 derivations)} module.
10114 In addition to options explicitly passed on the command line,
10115 @command{guix build} and other @command{guix} commands that support
10116 building honor the @env{GUIX_BUILD_OPTIONS} environment variable.
10118 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
10119 Users can define this variable to a list of command line options that
10120 will automatically be used by @command{guix build} and other
10121 @command{guix} commands that can perform builds, as in the example
10125 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
10128 These options are parsed independently, and the result is appended to
10129 the parsed command-line options.
10133 @node Package Transformation Options
10134 @subsection Package Transformation Options
10136 @cindex package variants
10137 Another set of command-line options supported by @command{guix build}
10138 and also @command{guix package} are @dfn{package transformation
10139 options}. These are options that make it possible to define @dfn{package
10140 variants}---for instance, packages built from different source code.
10141 This is a convenient way to create customized packages on the fly
10142 without having to type in the definitions of package variants
10143 (@pxref{Defining Packages}).
10145 Package transformation options are preserved across upgrades:
10146 @command{guix upgrade} attempts to apply transformation options
10147 initially used when creating the profile to the upgraded packages.
10149 The available options are listed below. Most commands support them and
10150 also support a @option{--help-transform} option that lists all the
10151 available options and a synopsis (these options are not shown in the
10152 @option{--help} output for brevity).
10156 @item --with-source=@var{source}
10157 @itemx --with-source=@var{package}=@var{source}
10158 @itemx --with-source=@var{package}@@@var{version}=@var{source}
10159 Use @var{source} as the source of @var{package}, and @var{version} as
10160 its version number.
10161 @var{source} must be a file name or a URL, as for @command{guix
10162 download} (@pxref{Invoking guix download}).
10164 When @var{package} is omitted,
10165 it is taken to be the package name specified on the
10166 command line that matches the base of @var{source}---e.g.,
10167 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
10168 package is @code{guile}.
10170 Likewise, when @var{version} is omitted, the version string is inferred from
10171 @var{source}; in the previous example, it is @code{2.0.10}.
10173 This option allows users to try out versions of packages other than the
10174 one provided by the distribution. The example below downloads
10175 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
10176 the @code{ed} package:
10179 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
10182 As a developer, @option{--with-source} makes it easy to test release
10186 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
10189 @dots{} or to build from a checkout in a pristine environment:
10192 $ git clone git://git.sv.gnu.org/guix.git
10193 $ guix build guix --with-source=guix@@1.0=./guix
10196 @item --with-input=@var{package}=@var{replacement}
10197 Replace dependency on @var{package} by a dependency on
10198 @var{replacement}. @var{package} must be a package name, and
10199 @var{replacement} must be a package specification such as @code{guile}
10200 or @code{guile@@1.8}.
10202 For instance, the following command builds Guix, but replaces its
10203 dependency on the current stable version of Guile with a dependency on
10204 the legacy version of Guile, @code{guile@@2.0}:
10207 guix build --with-input=guile=guile@@2.0 guix
10210 This is a recursive, deep replacement. So in this example, both
10211 @code{guix} and its dependency @code{guile-json} (which also depends on
10212 @code{guile}) get rebuilt against @code{guile@@2.0}.
10214 This is implemented using the @code{package-input-rewriting} Scheme
10215 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
10217 @item --with-graft=@var{package}=@var{replacement}
10218 This is similar to @option{--with-input} but with an important difference:
10219 instead of rebuilding the whole dependency chain, @var{replacement} is
10220 built and then @dfn{grafted} onto the binaries that were initially
10221 referring to @var{package}. @xref{Security Updates}, for more
10222 information on grafts.
10224 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
10225 and all its dependencies, replacing references to the version of GnuTLS
10226 they currently refer to:
10229 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
10232 This has the advantage of being much faster than rebuilding everything.
10233 But there is a caveat: it works if and only if @var{package} and
10234 @var{replacement} are strictly compatible---for example, if they provide
10235 a library, the application binary interface (ABI) of those libraries
10236 must be compatible. If @var{replacement} is somehow incompatible with
10237 @var{package}, then the resulting package may be unusable. Use with
10240 @cindex debugging info, rebuilding
10241 @item --with-debug-info=@var{package}
10242 Build @var{package} in a way that preserves its debugging info and graft
10243 it onto packages that depend on it. This is useful if @var{package}
10244 does not already provide debugging info as a @code{debug} output
10245 (@pxref{Installing Debugging Files}).
10247 For example, suppose you're experiencing a crash in Inkscape and would
10248 like to see what's up in GLib, a library deep down in Inkscape's
10249 dependency graph. GLib lacks a @code{debug} output, so debugging is
10250 tough. Fortunately, you rebuild GLib with debugging info and tack it on
10254 guix install inkscape --with-debug-info=glib
10257 Only GLib needs to be recompiled so this takes a reasonable amount of
10258 time. @xref{Installing Debugging Files}, for more info.
10261 Under the hood, this option works by passing the @samp{#:strip-binaries?
10262 #f} to the build system of the package of interest (@pxref{Build
10263 Systems}). Most build systems support that option but some do not. In
10264 that case, an error is raised.
10266 Likewise, if a C/C++ package is built without @code{-g} (which is rarely
10267 the case), debugging info will remain unavailable even when
10268 @code{#:strip-binaries?} is false.
10271 @cindex tool chain, changing the build tool chain of a package
10272 @item --with-c-toolchain=@var{package}=@var{toolchain}
10273 This option changes the compilation of @var{package} and everything that
10274 depends on it so that they get built with @var{toolchain} instead of the
10275 default GNU tool chain for C/C++.
10277 Consider this example:
10280 guix build octave-cli \
10281 --with-c-toolchain=fftw=gcc-toolchain@@10 \
10282 --with-c-toolchain=fftwf=gcc-toolchain@@10
10285 The command above builds a variant of the @code{fftw} and @code{fftwf}
10286 packages using version 10 of @code{gcc-toolchain} instead of the default
10287 tool chain, and then builds a variant of the GNU@tie{}Octave
10288 command-line interface using them. GNU@tie{}Octave itself is also built
10289 with @code{gcc-toolchain@@10}.
10291 This other example builds the Hardware Locality (@code{hwloc}) library
10292 and its dependents up to @code{intel-mpi-benchmarks} with the Clang C
10296 guix build --with-c-toolchain=hwloc=clang-toolchain \
10297 intel-mpi-benchmarks
10301 There can be application binary interface (ABI) incompatibilities among
10302 tool chains. This is particularly true of the C++ standard library and
10303 run-time support libraries such as that of OpenMP. By rebuilding all
10304 dependents with the same tool chain, @option{--with-c-toolchain} minimizes
10305 the risks of incompatibility but cannot entirely eliminate them. Choose
10306 @var{package} wisely.
10309 @item --with-git-url=@var{package}=@var{url}
10310 @cindex Git, using the latest commit
10311 @cindex latest commit, building
10312 Build @var{package} from the latest commit of the @code{master} branch of the
10313 Git repository at @var{url}. Git sub-modules of the repository are fetched,
10316 For example, the following command builds the NumPy Python library against the
10317 latest commit of the master branch of Python itself:
10320 guix build python-numpy \
10321 --with-git-url=python=https://github.com/python/cpython
10324 This option can also be combined with @option{--with-branch} or
10325 @option{--with-commit} (see below).
10327 @cindex continuous integration
10328 Obviously, since it uses the latest commit of the given branch, the result of
10329 such a command varies over time. Nevertheless it is a convenient way to
10330 rebuild entire software stacks against the latest commit of one or more
10331 packages. This is particularly useful in the context of continuous
10334 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
10335 consecutive accesses to the same repository. You may want to clean it up once
10336 in a while to save disk space.
10338 @item --with-branch=@var{package}=@var{branch}
10339 Build @var{package} from the latest commit of @var{branch}. If the
10340 @code{source} field of @var{package} is an origin with the @code{git-fetch}
10341 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
10342 repository URL is taken from that @code{source}. Otherwise you have to use
10343 @option{--with-git-url} to specify the URL of the Git repository.
10345 For instance, the following command builds @code{guile-sqlite3} from the
10346 latest commit of its @code{master} branch, and then builds @code{guix} (which
10347 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
10348 specific @code{guile-sqlite3} build:
10351 guix build --with-branch=guile-sqlite3=master cuirass
10354 @item --with-commit=@var{package}=@var{commit}
10355 This is similar to @option{--with-branch}, except that it builds from
10356 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
10357 Git commit SHA1 identifier or a tag.
10359 @cindex test suite, skipping
10360 @item --without-tests=@var{package}
10361 Build @var{package} without running its tests. This can be useful in
10362 situations where you want to skip the lengthy test suite of a
10363 intermediate package, or if a package's test suite fails in a
10364 non-deterministic fashion. It should be used with care because running
10365 the test suite is a good way to ensure a package is working as intended.
10367 Turning off tests leads to a different store item. Consequently, when
10368 using this option, anything that depends on @var{package} must be
10369 rebuilt, as in this example:
10372 guix install --without-tests=python python-notebook
10375 The command above installs @code{python-notebook} on top of
10376 @code{python} built without running its test suite. To do so, it also
10377 rebuilds everything that depends on @code{python}, including
10378 @code{python-notebook} itself.
10380 Internally, @option{--without-tests} relies on changing the
10381 @code{#:tests?} option of a package's @code{check} phase (@pxref{Build
10382 Systems}). Note that some packages use a customized @code{check} phase
10383 that does not respect a @code{#:tests? #f} setting. Therefore,
10384 @option{--without-tests} has no effect on these packages.
10388 Wondering how to achieve the same effect using Scheme code, for example
10389 in your manifest, or how to write your own package transformation?
10390 @xref{Defining Package Variants}, for an overview of the programming
10391 interfaces available.
10393 @node Additional Build Options
10394 @subsection Additional Build Options
10396 The command-line options presented below are specific to @command{guix
10403 Build quietly, without displaying the build log; this is equivalent to
10404 @option{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
10405 (or similar) and can always be retrieved using the @option{--log-file} option.
10407 @item --file=@var{file}
10408 @itemx -f @var{file}
10409 Build the package, derivation, or other file-like object that the code within
10410 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
10412 As an example, @var{file} might contain a package definition like this
10413 (@pxref{Defining Packages}):
10416 @include package-hello.scm
10419 The @var{file} may also contain a JSON representation of one or more
10420 package definitions. Running @code{guix build -f} on @file{hello.json}
10421 with the following contents would result in building the packages
10422 @code{myhello} and @code{greeter}:
10425 @verbatiminclude package-hello.json
10428 @item --manifest=@var{manifest}
10429 @itemx -m @var{manifest}
10430 Build all packages listed in the given @var{manifest}
10431 (@pxref{profile-manifest, @option{--manifest}}).
10433 @item --expression=@var{expr}
10434 @itemx -e @var{expr}
10435 Build the package or derivation @var{expr} evaluates to.
10437 For example, @var{expr} may be @code{(@@ (gnu packages guile)
10438 guile-1.8)}, which unambiguously designates this specific variant of
10439 version 1.8 of Guile.
10441 Alternatively, @var{expr} may be a G-expression, in which case it is used
10442 as a build program passed to @code{gexp->derivation}
10443 (@pxref{G-Expressions}).
10445 Lastly, @var{expr} may refer to a zero-argument monadic procedure
10446 (@pxref{The Store Monad}). The procedure must return a derivation as a
10447 monadic value, which is then passed through @code{run-with-store}.
10451 Build the source derivations of the packages, rather than the packages
10454 For instance, @code{guix build -S gcc} returns something like
10455 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
10458 The returned source tarball is the result of applying any patches and
10459 code snippets specified in the package @code{origin} (@pxref{Defining
10462 @cindex source, verification
10463 As with other derivations, the result of building a source derivation
10464 can be verified using the @option{--check} option (@pxref{build-check}).
10465 This is useful to validate that a (potentially already built or
10466 substituted, thus cached) package source matches against its declared
10469 Note that @command{guix build -S} compiles the sources only of the
10470 specified packages. They do not include the sources of statically
10471 linked dependencies and by themselves are insufficient for reproducing
10475 Fetch and return the source of @var{package-or-derivation} and all their
10476 dependencies, recursively. This is a handy way to obtain a local copy
10477 of all the source code needed to build @var{packages}, allowing you to
10478 eventually build them even without network access. It is an extension
10479 of the @option{--source} option and can accept one of the following
10480 optional argument values:
10484 This value causes the @option{--sources} option to behave in the same way
10485 as the @option{--source} option.
10488 Build the source derivations of all packages, including any source that
10489 might be listed as @code{inputs}. This is the default value.
10492 $ guix build --sources tzdata
10493 The following derivations will be built:
10494 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
10495 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
10499 Build the source derivations of all packages, as well of all transitive
10500 inputs to the packages. This can be used e.g.@: to
10501 prefetch package source for later offline building.
10504 $ guix build --sources=transitive tzdata
10505 The following derivations will be built:
10506 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
10507 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
10508 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
10509 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
10510 /gnu/store/@dots{}-make-4.1.tar.xz.drv
10511 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
10517 @item --system=@var{system}
10518 @itemx -s @var{system}
10519 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
10520 the system type of the build host. The @command{guix build} command allows
10521 you to repeat this option several times, in which case it builds for all the
10522 specified systems; other commands ignore extraneous @option{-s} options.
10525 The @option{--system} flag is for @emph{native} compilation and must not
10526 be confused with cross-compilation. See @option{--target} below for
10527 information on cross-compilation.
10530 An example use of this is on Linux-based systems, which can emulate
10531 different personalities. For instance, passing
10532 @option{--system=i686-linux} on an @code{x86_64-linux} system or
10533 @option{--system=armhf-linux} on an @code{aarch64-linux} system allows
10534 you to build packages in a complete 32-bit environment.
10537 Building for an @code{armhf-linux} system is unconditionally enabled on
10538 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
10539 allow for this functionality, notably the ThunderX.
10542 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
10543 is enabled (@pxref{Virtualization Services,
10544 @code{qemu-binfmt-service-type}}), you can build for any system for
10545 which a QEMU @code{binfmt_misc} handler is installed.
10547 Builds for a system other than that of the machine you are using can
10548 also be offloaded to a remote machine of the right architecture.
10549 @xref{Daemon Offload Setup}, for more information on offloading.
10551 @item --target=@var{triplet}
10552 @cindex cross-compilation
10553 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
10554 as @code{"aarch64-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
10555 configuration triplets,, autoconf, Autoconf}).
10557 @anchor{build-check}
10559 @cindex determinism, checking
10560 @cindex reproducibility, checking
10561 Rebuild @var{package-or-derivation}, which are already available in the
10562 store, and raise an error if the build results are not bit-for-bit
10565 This mechanism allows you to check whether previously installed
10566 substitutes are genuine (@pxref{Substitutes}), or whether the build result
10567 of a package is deterministic. @xref{Invoking guix challenge}, for more
10568 background information and tools.
10570 When used in conjunction with @option{--keep-failed}, the differing
10571 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
10572 This makes it easy to look for differences between the two results.
10575 @cindex repairing store items
10576 @cindex corruption, recovering from
10577 Attempt to repair the specified store items, if they are corrupt, by
10578 re-downloading or rebuilding them.
10580 This operation is not atomic and thus restricted to @code{root}.
10582 @item --derivations
10584 Return the derivation paths, not the output paths, of the given
10587 @item --root=@var{file}
10588 @itemx -r @var{file}
10589 @cindex GC roots, adding
10590 @cindex garbage collector roots, adding
10591 Make @var{file} a symlink to the result, and register it as a garbage
10594 Consequently, the results of this @command{guix build} invocation are
10595 protected from garbage collection until @var{file} is removed. When
10596 that option is omitted, build results are eligible for garbage
10597 collection as soon as the build completes. @xref{Invoking guix gc}, for
10601 @cindex build logs, access
10602 Return the build log file names or URLs for the given
10603 @var{package-or-derivation}, or raise an error if build logs are
10606 This works regardless of how packages or derivations are specified. For
10607 instance, the following invocations are equivalent:
10610 guix build --log-file `guix build -d guile`
10611 guix build --log-file `guix build guile`
10612 guix build --log-file guile
10613 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
10616 If a log is unavailable locally, and unless @option{--no-substitutes} is
10617 passed, the command looks for a corresponding log on one of the
10618 substitute servers (as specified with @option{--substitute-urls}).
10620 So for instance, imagine you want to see the build log of GDB on MIPS,
10621 but you are actually on an @code{x86_64} machine:
10624 $ guix build --log-file gdb -s aarch64-linux
10625 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
10628 You can freely access a huge library of build logs!
10631 @node Debugging Build Failures
10632 @subsection Debugging Build Failures
10634 @cindex build failures, debugging
10635 When defining a new package (@pxref{Defining Packages}), you will
10636 probably find yourself spending some time debugging and tweaking the
10637 build until it succeeds. To do that, you need to operate the build
10638 commands yourself in an environment as close as possible to the one the
10641 To that end, the first thing to do is to use the @option{--keep-failed}
10642 or @option{-K} option of @command{guix build}, which will keep the
10643 failed build tree in @file{/tmp} or whatever directory you specified as
10644 @env{TMPDIR} (@pxref{Invoking guix build, @option{--keep-failed}}).
10646 From there on, you can @command{cd} to the failed build tree and source
10647 the @file{environment-variables} file, which contains all the
10648 environment variable definitions that were in place when the build
10649 failed. So let's say you're debugging a build failure in package
10650 @code{foo}; a typical session would look like this:
10653 $ guix build foo -K
10654 @dots{} @i{build fails}
10655 $ cd /tmp/guix-build-foo.drv-0
10656 $ source ./environment-variables
10660 Now, you can invoke commands as if you were the daemon (almost) and
10661 troubleshoot your build process.
10663 Sometimes it happens that, for example, a package's tests pass when you
10664 run them manually but they fail when the daemon runs them. This can
10665 happen because the daemon runs builds in containers where, unlike in our
10666 environment above, network access is missing, @file{/bin/sh} does not
10667 exist, etc. (@pxref{Build Environment Setup}).
10669 In such cases, you may need to run inspect the build process from within
10670 a container similar to the one the build daemon creates:
10673 $ guix build -K foo
10675 $ cd /tmp/guix-build-foo.drv-0
10676 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
10677 [env]# source ./environment-variables
10681 Here, @command{guix environment -C} creates a container and spawns a new
10682 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
10683 strace gdb} part adds the @command{strace} and @command{gdb} commands to
10684 the container, which you may find handy while debugging. The
10685 @option{--no-grafts} option makes sure we get the exact same
10686 environment, with ungrafted packages (@pxref{Security Updates}, for more
10689 To get closer to a container like that used by the build daemon, we can
10690 remove @file{/bin/sh}:
10696 (Don't worry, this is harmless: this is all happening in the throw-away
10697 container created by @command{guix environment}.)
10699 The @command{strace} command is probably not in the search path, but we
10703 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
10706 In this way, not only you will have reproduced the environment variables
10707 the daemon uses, you will also be running the build process in a container
10708 similar to the one the daemon uses.
10711 @node Invoking guix edit
10712 @section Invoking @command{guix edit}
10714 @cindex @command{guix edit}
10715 @cindex package definition, editing
10716 So many packages, so many source files! The @command{guix edit} command
10717 facilitates the life of users and packagers by pointing their editor at
10718 the source file containing the definition of the specified packages.
10722 guix edit gcc@@4.9 vim
10726 launches the program specified in the @env{VISUAL} or in the
10727 @env{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
10730 If you are using a Guix Git checkout (@pxref{Building from Git}), or
10731 have created your own packages on @env{GUIX_PACKAGE_PATH}
10732 (@pxref{Package Modules}), you will be able to edit the package
10733 recipes. In other cases, you will be able to examine the read-only recipes
10734 for packages currently in the store.
10736 Instead of @env{GUIX_PACKAGE_PATH}, the command-line option
10737 @option{--load-path=@var{directory}} (or in short @option{-L
10738 @var{directory}}) allows you to add @var{directory} to the front of the
10739 package module search path and so make your own packages visible.
10741 @node Invoking guix download
10742 @section Invoking @command{guix download}
10744 @cindex @command{guix download}
10745 @cindex downloading package sources
10746 When writing a package definition, developers typically need to download
10747 a source tarball, compute its SHA256 hash, and write that
10748 hash in the package definition (@pxref{Defining Packages}). The
10749 @command{guix download} tool helps with this task: it downloads a file
10750 from the given URI, adds it to the store, and prints both its file name
10751 in the store and its SHA256 hash.
10753 The fact that the downloaded file is added to the store saves bandwidth:
10754 when the developer eventually tries to build the newly defined package
10755 with @command{guix build}, the source tarball will not have to be
10756 downloaded again because it is already in the store. It is also a
10757 convenient way to temporarily stash files, which may be deleted
10758 eventually (@pxref{Invoking guix gc}).
10760 The @command{guix download} command supports the same URIs as used in
10761 package definitions. In particular, it supports @code{mirror://} URIs.
10762 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
10763 Guile bindings for GnuTLS are available in the user's environment; when
10764 they are not available, an error is raised. @xref{Guile Preparations,
10765 how to install the GnuTLS bindings for Guile,, gnutls-guile,
10766 GnuTLS-Guile}, for more information.
10768 @command{guix download} verifies HTTPS server certificates by loading
10769 the certificates of X.509 authorities from the directory pointed to by
10770 the @env{SSL_CERT_DIR} environment variable (@pxref{X.509
10771 Certificates}), unless @option{--no-check-certificate} is used.
10773 The following options are available:
10776 @item --hash=@var{algorithm}
10777 @itemx -H @var{algorithm}
10778 Compute a hash using the specified @var{algorithm}. @xref{Invoking guix
10779 hash}, for more information.
10781 @item --format=@var{fmt}
10782 @itemx -f @var{fmt}
10783 Write the hash in the format specified by @var{fmt}. For more
10784 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
10786 @item --no-check-certificate
10787 Do not validate the X.509 certificates of HTTPS servers.
10789 When using this option, you have @emph{absolutely no guarantee} that you
10790 are communicating with the authentic server responsible for the given
10791 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
10793 @item --output=@var{file}
10794 @itemx -o @var{file}
10795 Save the downloaded file to @var{file} instead of adding it to the
10799 @node Invoking guix hash
10800 @section Invoking @command{guix hash}
10802 @cindex @command{guix hash}
10803 The @command{guix hash} command computes the hash of a file.
10804 It is primarily a convenience tool for anyone contributing to the
10805 distribution: it computes the cryptographic hash of a file, which can be
10806 used in the definition of a package (@pxref{Defining Packages}).
10808 The general syntax is:
10811 guix hash @var{option} @var{file}
10814 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
10815 hash of data read from standard input. @command{guix hash} has the
10820 @item --hash=@var{algorithm}
10821 @itemx -H @var{algorithm}
10822 Compute a hash using the specified @var{algorithm}, @code{sha256} by
10825 @var{algorithm} must the name of a cryptographic hash algorithm
10826 supported by Libgcrypt @i{via} Guile-Gcrypt---e.g., @code{sha512} or
10827 @code{sha3-256} (@pxref{Hash Functions,,, guile-gcrypt, Guile-Gcrypt
10828 Reference Manual}).
10830 @item --format=@var{fmt}
10831 @itemx -f @var{fmt}
10832 Write the hash in the format specified by @var{fmt}.
10834 Supported formats: @code{base64}, @code{nix-base32}, @code{base32}, @code{base16}
10835 (@code{hex} and @code{hexadecimal} can be used as well).
10837 If the @option{--format} option is not specified, @command{guix hash}
10838 will output the hash in @code{nix-base32}. This representation is used
10839 in the definitions of packages.
10843 Compute the hash on @var{file} recursively.
10845 In this case, the hash is computed on an archive containing @var{file},
10846 including its children if it is a directory. Some of the metadata of
10847 @var{file} is part of the archive; for instance, when @var{file} is a
10848 regular file, the hash is different depending on whether @var{file} is
10849 executable or not. Metadata such as time stamps has no impact on the
10850 hash (@pxref{Invoking guix archive}).
10851 @c FIXME: Replace xref above with xref to an ``Archive'' section when
10854 @item --exclude-vcs
10856 When combined with @option{--recursive}, exclude version control system
10857 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.).
10860 As an example, here is how you would compute the hash of a Git checkout,
10861 which is useful when using the @code{git-fetch} method (@pxref{origin
10865 $ git clone http://example.org/foo.git
10871 @node Invoking guix import
10872 @section Invoking @command{guix import}
10874 @cindex importing packages
10875 @cindex package import
10876 @cindex package conversion
10877 @cindex Invoking @command{guix import}
10878 The @command{guix import} command is useful for people who would like to
10879 add a package to the distribution with as little work as
10880 possible---a legitimate demand. The command knows of a few
10881 repositories from which it can ``import'' package metadata. The result
10882 is a package definition, or a template thereof, in the format we know
10883 (@pxref{Defining Packages}).
10885 The general syntax is:
10888 guix import @var{importer} @var{options}@dots{}
10891 @var{importer} specifies the source from which to import package
10892 metadata, and @var{options} specifies a package identifier and other
10893 options specific to @var{importer}.
10895 Some of the importers rely on the ability to run the @command{gpgv} command.
10896 For these, GnuPG must be installed and in @code{$PATH}; run @code{guix install
10899 Currently, the available ``importers'' are:
10903 Import metadata for the given GNU package. This provides a template
10904 for the latest version of that GNU package, including the hash of its
10905 source tarball, and its canonical synopsis and description.
10907 Additional information such as the package dependencies and its
10908 license needs to be figured out manually.
10910 For example, the following command returns a package definition for
10914 guix import gnu hello
10917 Specific command-line options are:
10920 @item --key-download=@var{policy}
10921 As for @command{guix refresh}, specify the policy to handle missing
10922 OpenPGP keys when verifying the package signature. @xref{Invoking guix
10923 refresh, @option{--key-download}}.
10928 Import metadata from the @uref{https://pypi.python.org/, Python Package
10929 Index}. Information is taken from the JSON-formatted description
10930 available at @code{pypi.python.org} and usually includes all the relevant
10931 information, including package dependencies. For maximum efficiency, it
10932 is recommended to install the @command{unzip} utility, so that the
10933 importer can unzip Python wheels and gather data from them.
10935 The command below imports metadata for the @code{itsdangerous} Python
10939 guix import pypi itsdangerous
10945 Traverse the dependency graph of the given upstream package recursively
10946 and generate package expressions for all those packages that are not yet
10952 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
10953 is taken from the JSON-formatted description available at
10954 @code{rubygems.org} and includes most relevant information, including
10955 runtime dependencies. There are some caveats, however. The metadata
10956 doesn't distinguish between synopses and descriptions, so the same string
10957 is used for both fields. Additionally, the details of non-Ruby
10958 dependencies required to build native extensions is unavailable and left
10959 as an exercise to the packager.
10961 The command below imports metadata for the @code{rails} Ruby package:
10964 guix import gem rails
10970 Traverse the dependency graph of the given upstream package recursively
10971 and generate package expressions for all those packages that are not yet
10977 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
10978 Information is taken from the JSON-formatted metadata provided through
10979 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
10980 relevant information, such as module dependencies. License information
10981 should be checked closely. If Perl is available in the store, then the
10982 @code{corelist} utility will be used to filter core modules out of the
10983 list of dependencies.
10985 The command command below imports metadata for the Acme::Boolean Perl
10989 guix import cpan Acme::Boolean
10994 @cindex Bioconductor
10995 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
10996 central repository for the @uref{https://r-project.org, GNU@tie{}R
10997 statistical and graphical environment}.
10999 Information is extracted from the @file{DESCRIPTION} file of the package.
11001 The command command below imports metadata for the Cairo R package:
11004 guix import cran Cairo
11007 When @option{--recursive} is added, the importer will traverse the
11008 dependency graph of the given upstream package recursively and generate
11009 package expressions for all those packages that are not yet in Guix.
11011 When @option{--archive=bioconductor} is added, metadata is imported from
11012 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
11013 packages for the analysis and comprehension of high-throughput
11014 genomic data in bioinformatics.
11016 Information is extracted from the @file{DESCRIPTION} file contained in the
11019 The command below imports metadata for the GenomicRanges R package:
11022 guix import cran --archive=bioconductor GenomicRanges
11025 Finally, you can also import R packages that have not yet been published on
11026 CRAN or Bioconductor as long as they are in a git repository. Use
11027 @option{--archive=git} followed by the URL of the git repository:
11030 guix import cran --archive=git https://github.com/immunogenomics/harmony
11036 Import metadata from @uref{https://www.ctan.org/, CTAN}, the
11037 comprehensive TeX archive network for TeX packages that are part of the
11038 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
11040 Information about the package is obtained through the XML API provided
11041 by CTAN, while the source code is downloaded from the SVN repository of
11042 the Tex Live project. This is done because the CTAN does not keep
11043 versioned archives.
11045 The command command below imports metadata for the @code{fontspec}
11049 guix import texlive fontspec
11052 When @option{--archive=@var{directory}} is added, the source code is
11053 downloaded not from the @file{latex} sub-directory of the
11054 @file{texmf-dist/source} tree in the TeX Live SVN repository, but from
11055 the specified sibling @var{directory} under the same root.
11057 The command below imports metadata for the @code{ifxetex} package from
11058 CTAN while fetching the sources from the directory
11059 @file{texmf/source/generic}:
11062 guix import texlive --archive=generic ifxetex
11066 @cindex JSON, import
11067 Import package metadata from a local JSON file. Consider the following
11068 example package definition in JSON format:
11074 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
11075 "build-system": "gnu",
11076 "home-page": "https://www.gnu.org/software/hello/",
11077 "synopsis": "Hello, GNU world: An example GNU package",
11078 "description": "GNU Hello prints a greeting.",
11079 "license": "GPL-3.0+",
11080 "native-inputs": ["gettext"]
11084 The field names are the same as for the @code{<package>} record
11085 (@xref{Defining Packages}). References to other packages are provided
11086 as JSON lists of quoted package specification strings such as
11087 @code{guile} or @code{guile@@2.0}.
11089 The importer also supports a more explicit source definition using the
11090 common fields for @code{<origin>} records:
11096 "method": "url-fetch",
11097 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
11099 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
11106 The command below reads metadata from the JSON file @code{hello.json}
11107 and outputs a package expression:
11110 guix import json hello.json
11114 Import metadata from a local copy of the source of the
11115 @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
11116 relies on the @command{nix-instantiate} command of
11117 @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
11118 typically written in a mixture of Nix-language and Bash code. This
11119 command only imports the high-level package structure that is written in
11120 the Nix language. It normally includes all the basic fields of a
11121 package definition.
11123 When importing a GNU package, the synopsis and descriptions are replaced
11124 by their canonical upstream variant.
11126 Usually, you will first need to do:
11129 export NIX_REMOTE=daemon
11133 so that @command{nix-instantiate} does not try to open the Nix database.
11135 As an example, the command below imports the package definition of
11136 LibreOffice (more precisely, it imports the definition of the package
11137 bound to the @code{libreoffice} top-level attribute):
11140 guix import nix ~/path/to/nixpkgs libreoffice
11145 Import metadata from the Haskell community's central package archive
11146 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
11147 Cabal files and includes all the relevant information, including package
11150 Specific command-line options are:
11155 Read a Cabal file from standard input.
11156 @item --no-test-dependencies
11158 Do not include dependencies required only by the test suites.
11159 @item --cabal-environment=@var{alist}
11160 @itemx -e @var{alist}
11161 @var{alist} is a Scheme alist defining the environment in which the
11162 Cabal conditionals are evaluated. The accepted keys are: @code{os},
11163 @code{arch}, @code{impl} and a string representing the name of a flag.
11164 The value associated with a flag has to be either the symbol
11165 @code{true} or @code{false}. The value associated with other keys
11166 has to conform to the Cabal file format definition. The default value
11167 associated with the keys @code{os}, @code{arch} and @code{impl} is
11168 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
11171 Traverse the dependency graph of the given upstream package recursively
11172 and generate package expressions for all those packages that are not yet
11176 The command below imports metadata for the latest version of the
11177 HTTP Haskell package without including test dependencies and
11178 specifying the value of the flag @samp{network-uri} as @code{false}:
11181 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
11184 A specific package version may optionally be specified by following the
11185 package name by an at-sign and a version number as in the following example:
11188 guix import hackage mtl@@2.1.3.1
11193 The @code{stackage} importer is a wrapper around the @code{hackage} one.
11194 It takes a package name, looks up the package version included in a
11195 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
11196 release and uses the @code{hackage} importer to retrieve its metadata.
11197 Note that it is up to you to select an LTS release compatible with the
11198 GHC compiler used by Guix.
11200 Specific command-line options are:
11203 @item --no-test-dependencies
11205 Do not include dependencies required only by the test suites.
11206 @item --lts-version=@var{version}
11207 @itemx -l @var{version}
11208 @var{version} is the desired LTS release version. If omitted the latest
11212 Traverse the dependency graph of the given upstream package recursively
11213 and generate package expressions for all those packages that are not yet
11217 The command below imports metadata for the HTTP Haskell package
11218 included in the LTS Stackage release version 7.18:
11221 guix import stackage --lts-version=7.18 HTTP
11226 Import metadata from an Emacs Lisp Package Archive (ELPA) package
11227 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
11229 Specific command-line options are:
11232 @item --archive=@var{repo}
11233 @itemx -a @var{repo}
11234 @var{repo} identifies the archive repository from which to retrieve the
11235 information. Currently the supported repositories and their identifiers
11239 @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
11240 identifier. This is the default.
11242 Packages from @code{elpa.gnu.org} are signed with one of the keys
11243 contained in the GnuPG keyring at
11244 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
11245 @code{emacs} package (@pxref{Package Installation, ELPA package
11246 signatures,, emacs, The GNU Emacs Manual}).
11249 @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
11250 @code{melpa-stable} identifier.
11253 @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
11259 Traverse the dependency graph of the given upstream package recursively
11260 and generate package expressions for all those packages that are not yet
11266 Import metadata from the crates.io Rust package repository
11267 @uref{https://crates.io, crates.io}, as in this example:
11270 guix import crate blake2-rfc
11273 The crate importer also allows you to specify a version string:
11276 guix import crate constant-time-eq@@0.1.0
11279 Additional options include:
11284 Traverse the dependency graph of the given upstream package recursively
11285 and generate package expressions for all those packages that are not yet
11292 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
11293 repository used by the OCaml community.
11295 Additional options include:
11300 Traverse the dependency graph of the given upstream package recursively
11301 and generate package expressions for all those packages that are not yet
11304 Select the given repository (a repository name). Possible values include:
11306 @item @code{opam}, the default opam repository,
11307 @item @code{coq} or @code{coq-released}, the stable repository for coq packages,
11308 @item @code{coq-core-dev}, the repository that contains development versions of coq,
11309 @item @code{coq-extra-dev}, the repository that contains development versions
11315 The structure of the @command{guix import} code is modular. It would be
11316 useful to have more importers for other package formats, and your help
11317 is welcome here (@pxref{Contributing}).
11319 @node Invoking guix refresh
11320 @section Invoking @command{guix refresh}
11322 @cindex @command {guix refresh}
11323 The primary audience of the @command{guix refresh} command is developers
11324 of the GNU software distribution. By default, it reports any packages
11325 provided by the distribution that are outdated compared to the latest
11326 upstream version, like this:
11330 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
11331 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
11334 Alternatively, one can specify packages to consider, in which case a
11335 warning is emitted for packages that lack an updater:
11338 $ guix refresh coreutils guile guile-ssh
11339 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
11340 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
11343 @command{guix refresh} browses the upstream repository of each package and determines
11344 the highest version number of the releases therein. The command
11345 knows how to update specific types of packages: GNU packages, ELPA
11346 packages, etc.---see the documentation for @option{--type} below. There
11347 are many packages, though, for which it lacks a method to determine
11348 whether a new upstream release is available. However, the mechanism is
11349 extensible, so feel free to get in touch with us to add a new method!
11354 Consider the packages specified, and all the packages upon which they depend.
11357 $ guix refresh --recursive coreutils
11358 gnu/packages/acl.scm:35:2: warning: no updater for acl
11359 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
11360 gnu/packages/xml.scm:68:2: warning: no updater for expat
11361 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
11367 Sometimes the upstream name differs from the package name used in Guix,
11368 and @command{guix refresh} needs a little help. Most updaters honor the
11369 @code{upstream-name} property in package definitions, which can be used
11373 (define-public network-manager
11375 (name "network-manager")
11377 (properties '((upstream-name . "NetworkManager")))))
11380 When passed @option{--update}, it modifies distribution source files to
11381 update the version numbers and source tarball hashes of those package
11382 recipes (@pxref{Defining Packages}). This is achieved by downloading
11383 each package's latest source tarball and its associated OpenPGP
11384 signature, authenticating the downloaded tarball against its signature
11385 using @command{gpgv}, and finally computing its hash---note that GnuPG must be
11386 installed and in @code{$PATH}; run @code{guix install gnupg} if needed.
11389 key used to sign the tarball is missing from the user's keyring, an
11390 attempt is made to automatically retrieve it from a public key server;
11391 when this is successful, the key is added to the user's keyring; otherwise,
11392 @command{guix refresh} reports an error.
11394 The following options are supported:
11398 @item --expression=@var{expr}
11399 @itemx -e @var{expr}
11400 Consider the package @var{expr} evaluates to.
11402 This is useful to precisely refer to a package, as in this example:
11405 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
11408 This command lists the dependents of the ``final'' libc (essentially all
11413 Update distribution source files (package recipes) in place. This is
11414 usually run from a checkout of the Guix source tree (@pxref{Running
11415 Guix Before It Is Installed}):
11418 $ ./pre-inst-env guix refresh -s non-core -u
11421 @xref{Defining Packages}, for more information on package definitions.
11423 @item --select=[@var{subset}]
11424 @itemx -s @var{subset}
11425 Select all the packages in @var{subset}, one of @code{core} or
11428 The @code{core} subset refers to all the packages at the core of the
11429 distribution---i.e., packages that are used to build ``everything
11430 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
11431 changing one of these packages in the distribution entails a rebuild of
11432 all the others. Thus, such updates are an inconvenience to users in
11433 terms of build time or bandwidth used to achieve the upgrade.
11435 The @code{non-core} subset refers to the remaining packages. It is
11436 typically useful in cases where an update of the core packages would be
11439 @item --manifest=@var{file}
11440 @itemx -m @var{file}
11441 Select all the packages from the manifest in @var{file}. This is useful to
11442 check if any packages of the user manifest can be updated.
11444 @item --type=@var{updater}
11445 @itemx -t @var{updater}
11446 Select only packages handled by @var{updater} (may be a comma-separated
11447 list of updaters). Currently, @var{updater} may be one of:
11451 the updater for GNU packages;
11453 the updater for packages hosted at @uref{https://savannah.gnu.org, Savannah};
11455 the updater for GNOME packages;
11457 the updater for KDE packages;
11459 the updater for X.org packages;
11461 the updater for packages hosted on kernel.org;
11463 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
11465 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
11467 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
11469 the updater for @uref{https://www.cpan.org/, CPAN} packages;
11471 the updater for @uref{https://pypi.python.org, PyPI} packages.
11473 the updater for @uref{https://rubygems.org, RubyGems} packages.
11475 the updater for @uref{https://github.com, GitHub} packages.
11477 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
11479 the updater for @uref{https://www.stackage.org, Stackage} packages.
11481 the updater for @uref{https://crates.io, Crates} packages.
11483 the updater for @uref{https://launchpad.net, Launchpad} packages.
11486 For instance, the following command only checks for updates of Emacs
11487 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
11490 $ guix refresh --type=elpa,cran
11491 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
11492 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
11497 In addition, @command{guix refresh} can be passed one or more package
11498 names, as in this example:
11501 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
11505 The command above specifically updates the @code{emacs} and
11506 @code{idutils} packages. The @option{--select} option would have no
11507 effect in this case.
11509 When considering whether to upgrade a package, it is sometimes
11510 convenient to know which packages would be affected by the upgrade and
11511 should be checked for compatibility. For this the following option may
11512 be used when passing @command{guix refresh} one or more package names:
11516 @item --list-updaters
11518 List available updaters and exit (see @option{--type} above).
11520 For each updater, display the fraction of packages it covers; at the
11521 end, display the fraction of packages covered by all these updaters.
11523 @item --list-dependent
11525 List top-level dependent packages that would need to be rebuilt as a
11526 result of upgrading one or more packages.
11528 @xref{Invoking guix graph, the @code{reverse-package} type of
11529 @command{guix graph}}, for information on how to visualize the list of
11530 dependents of a package.
11534 Be aware that the @option{--list-dependent} option only
11535 @emph{approximates} the rebuilds that would be required as a result of
11536 an upgrade. More rebuilds might be required under some circumstances.
11539 $ guix refresh --list-dependent flex
11540 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
11541 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
11544 The command above lists a set of packages that could be built to check
11545 for compatibility with an upgraded @code{flex} package.
11549 @item --list-transitive
11550 List all the packages which one or more packages depend upon.
11553 $ guix refresh --list-transitive flex
11554 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
11555 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{}
11560 The command above lists a set of packages which, when changed, would cause
11561 @code{flex} to be rebuilt.
11563 The following options can be used to customize GnuPG operation:
11567 @item --gpg=@var{command}
11568 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
11569 for in @code{$PATH}.
11571 @item --keyring=@var{file}
11572 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
11573 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
11574 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
11575 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
11576 information on a tool to manipulate keybox files).
11578 When this option is omitted, @command{guix refresh} uses
11579 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
11580 signing keys. OpenPGP signatures are checked against keys from this keyring;
11581 missing keys are downloaded to this keyring as well (see
11582 @option{--key-download} below).
11584 You can export keys from your default GPG keyring into a keybox file using
11585 commands like this one:
11588 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
11591 Likewise, you can fetch keys to a specific keybox file like this:
11594 gpg --no-default-keyring --keyring mykeyring.kbx \
11595 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
11598 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
11599 Privacy Guard}, for more information on GPG's @option{--keyring} option.
11601 @item --key-download=@var{policy}
11602 Handle missing OpenPGP keys according to @var{policy}, which may be one
11607 Always download missing OpenPGP keys from the key server, and add them
11608 to the user's GnuPG keyring.
11611 Never try to download missing OpenPGP keys. Instead just bail out.
11614 When a package signed with an unknown OpenPGP key is encountered, ask
11615 the user whether to download it or not. This is the default behavior.
11618 @item --key-server=@var{host}
11619 Use @var{host} as the OpenPGP key server when importing a public key.
11621 @item --load-path=@var{directory}
11622 Add @var{directory} to the front of the package module search path
11623 (@pxref{Package Modules}).
11625 This allows users to define their own packages and make them visible to
11626 the command-line tools.
11630 The @code{github} updater uses the
11631 @uref{https://developer.github.com/v3/, GitHub API} to query for new
11632 releases. When used repeatedly e.g.@: when refreshing all packages,
11633 GitHub will eventually refuse to answer any further API requests. By
11634 default 60 API requests per hour are allowed, and a full refresh on all
11635 GitHub packages in Guix requires more than this. Authentication with
11636 GitHub through the use of an API token alleviates these limits. To use
11637 an API token, set the environment variable @env{GUIX_GITHUB_TOKEN} to a
11638 token procured from @uref{https://github.com/settings/tokens} or
11642 @node Invoking guix lint
11643 @section Invoking @command{guix lint}
11645 @cindex @command{guix lint}
11646 @cindex package, checking for errors
11647 The @command{guix lint} command is meant to help package developers avoid
11648 common errors and use a consistent style. It runs a number of checks on
11649 a given set of packages in order to find common mistakes in their
11650 definitions. Available @dfn{checkers} include (see
11651 @option{--list-checkers} for a complete list):
11656 Validate certain typographical and stylistic rules about package
11657 descriptions and synopses.
11659 @item inputs-should-be-native
11660 Identify inputs that should most likely be native inputs.
11666 @itemx source-file-name
11667 Probe @code{home-page} and @code{source} URLs and report those that are
11668 invalid. Suggest a @code{mirror://} URL when applicable. If the
11669 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
11670 URL. Check that the source file name is meaningful, e.g.@: is not just a
11671 version number or ``git-checkout'', without a declared @code{file-name}
11672 (@pxref{origin Reference}).
11674 @item source-unstable-tarball
11675 Parse the @code{source} URL to determine if a tarball from GitHub is
11676 autogenerated or if it is a release tarball. Unfortunately GitHub's
11677 autogenerated tarballs are sometimes regenerated.
11680 Check that the derivation of the given packages can be successfully
11681 computed for all the supported systems (@pxref{Derivations}).
11683 @item profile-collisions
11684 Check whether installing the given packages in a profile would lead to
11685 collisions. Collisions occur when several packages with the same name
11686 but a different version or a different store file name are propagated.
11687 @xref{package Reference, @code{propagated-inputs}}, for more information
11688 on propagated inputs.
11691 @cindex Software Heritage, source code archive
11692 @cindex archival of source code, Software Heritage
11693 Checks whether the package's source code is archived at
11694 @uref{https://www.softwareheritage.org, Software Heritage}.
11696 When the source code that is not archived comes from a version-control system
11697 (VCS)---e.g., it's obtained with @code{git-fetch}, send Software Heritage a
11698 ``save'' request so that it eventually archives it. This ensures that the
11699 source will remain available in the long term, and that Guix can fall back to
11700 Software Heritage should the source code disappear from its original host.
11701 The status of recent ``save'' requests can be
11702 @uref{https://archive.softwareheritage.org/save/#requests, viewed on-line}.
11704 When source code is a tarball obtained with @code{url-fetch}, simply print a
11705 message when it is not archived. As of this writing, Software Heritage does
11706 not allow requests to save arbitrary tarballs; we are working on ways to
11707 ensure that non-VCS source code is also archived.
11710 @uref{https://archive.softwareheritage.org/api/#rate-limiting, limits the
11711 request rate per IP address}. When the limit is reached, @command{guix lint}
11712 prints a message and the @code{archival} checker stops doing anything until
11713 that limit has been reset.
11716 @cindex security vulnerabilities
11717 @cindex CVE, Common Vulnerabilities and Exposures
11718 Report known vulnerabilities found in the Common Vulnerabilities and
11719 Exposures (CVE) databases of the current and past year
11720 @uref{https://nvd.nist.gov/vuln/data-feeds, published by the US
11723 To view information about a particular vulnerability, visit pages such as:
11727 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
11729 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
11733 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
11734 @code{CVE-2015-7554}.
11736 Package developers can specify in package recipes the
11737 @uref{https://nvd.nist.gov/products/cpe,Common Platform Enumeration (CPE)}
11738 name and version of the package when they differ from the name or version
11739 that Guix uses, as in this example:
11745 ;; CPE calls this package "grub2".
11746 (properties '((cpe-name . "grub2")
11747 (cpe-version . "2.3"))))
11750 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
11751 Some entries in the CVE database do not specify which version of a
11752 package they apply to, and would thus ``stick around'' forever. Package
11753 developers who found CVE alerts and verified they can be ignored can
11754 declare them as in this example:
11760 ;; These CVEs no longer apply and can be safely ignored.
11761 (properties `((lint-hidden-cve . ("CVE-2011-0433"
11764 "CVE-2011-5244")))))
11768 Warn about obvious source code formatting issues: trailing white space,
11769 use of tabulations, etc.
11772 The general syntax is:
11775 guix lint @var{options} @var{package}@dots{}
11778 If no package is given on the command line, then all packages are checked.
11779 The @var{options} may be zero or more of the following:
11782 @item --list-checkers
11784 List and describe all the available checkers that will be run on packages
11789 Only enable the checkers specified in a comma-separated list using the
11790 names returned by @option{--list-checkers}.
11794 Only disable the checkers specified in a comma-separated list using the
11795 names returned by @option{--list-checkers}.
11799 Only enable the checkers that do not depend on Internet access.
11801 @item --load-path=@var{directory}
11802 @itemx -L @var{directory}
11803 Add @var{directory} to the front of the package module search path
11804 (@pxref{Package Modules}).
11806 This allows users to define their own packages and make them visible to
11807 the command-line tools.
11811 @node Invoking guix size
11812 @section Invoking @command{guix size}
11815 @cindex package size
11817 @cindex @command{guix size}
11818 The @command{guix size} command helps package developers profile the
11819 disk usage of packages. It is easy to overlook the impact of an
11820 additional dependency added to a package, or the impact of using a
11821 single output for a package that could easily be split (@pxref{Packages
11822 with Multiple Outputs}). Such are the typical issues that
11823 @command{guix size} can highlight.
11825 The command can be passed one or more package specifications
11826 such as @code{gcc@@4.8}
11827 or @code{guile:debug}, or a file name in the store. Consider this
11831 $ guix size coreutils
11832 store item total self
11833 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
11834 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
11835 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
11836 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
11837 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
11838 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
11839 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
11840 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
11845 The store items listed here constitute the @dfn{transitive closure} of
11846 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
11847 would be returned by:
11850 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
11853 Here the output shows three columns next to store items. The first column,
11854 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
11855 the store item---that is, its own size plus the size of all its
11856 dependencies. The next column, labeled ``self'', shows the size of the
11857 item itself. The last column shows the ratio of the size of the item
11858 itself to the space occupied by all the items listed here.
11860 In this example, we see that the closure of Coreutils weighs in at
11861 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
11862 libraries. (That libc and GCC's libraries represent a large fraction of
11863 the closure is not a problem @i{per se} because they are always available
11864 on the system anyway.)
11866 Since the command also accepts store file names, assessing the size of
11867 a build result is straightforward:
11870 guix size $(guix system build config.scm)
11873 When the package(s) passed to @command{guix size} are available in the
11874 store@footnote{More precisely, @command{guix size} looks for the
11875 @emph{ungrafted} variant of the given package(s), as returned by
11876 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
11877 for information on grafts.}, @command{guix size} queries the daemon to determine its
11878 dependencies, and measures its size in the store, similar to @command{du
11879 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
11882 When the given packages are @emph{not} in the store, @command{guix size}
11883 reports information based on the available substitutes
11884 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
11885 store items that are not even on disk, only available remotely.
11887 You can also specify several package names:
11890 $ guix size coreutils grep sed bash
11891 store item total self
11892 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
11893 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
11894 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
11895 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
11901 In this example we see that the combination of the four packages takes
11902 102.3@tie{}MiB in total, which is much less than the sum of each closure
11903 since they have a lot of dependencies in common.
11905 When looking at the profile returned by @command{guix size}, you may
11906 find yourself wondering why a given package shows up in the profile at
11907 all. To understand it, you can use @command{guix graph --path -t
11908 references} to display the shortest path between the two packages
11909 (@pxref{Invoking guix graph}).
11911 The available options are:
11915 @item --substitute-urls=@var{urls}
11916 Use substitute information from @var{urls}.
11917 @xref{client-substitute-urls, the same option for @code{guix build}}.
11919 @item --sort=@var{key}
11920 Sort lines according to @var{key}, one of the following options:
11924 the size of each item (the default);
11926 the total size of the item's closure.
11929 @item --map-file=@var{file}
11930 Write a graphical map of disk usage in PNG format to @var{file}.
11932 For the example above, the map looks like this:
11934 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
11935 produced by @command{guix size}}
11937 This option requires that
11938 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
11939 installed and visible in Guile's module search path. When that is not
11940 the case, @command{guix size} fails as it tries to load it.
11942 @item --system=@var{system}
11943 @itemx -s @var{system}
11944 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
11946 @item --load-path=@var{directory}
11947 @itemx -L @var{directory}
11948 Add @var{directory} to the front of the package module search path
11949 (@pxref{Package Modules}).
11951 This allows users to define their own packages and make them visible to
11952 the command-line tools.
11955 @node Invoking guix graph
11956 @section Invoking @command{guix graph}
11959 @cindex @command{guix graph}
11960 @cindex package dependencies
11961 Packages and their dependencies form a @dfn{graph}, specifically a
11962 directed acyclic graph (DAG). It can quickly become difficult to have a
11963 mental model of the package DAG, so the @command{guix graph} command
11964 provides a visual representation of the DAG. By default,
11965 @command{guix graph} emits a DAG representation in the input format of
11966 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
11967 directly to the @command{dot} command of Graphviz. It can also emit an
11968 HTML page with embedded JavaScript code to display a ``chord diagram''
11969 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
11970 emit Cypher queries to construct a graph in a graph database supporting
11971 the @uref{https://www.opencypher.org/, openCypher} query language. With
11972 @option{--path}, it simply displays the shortest path between two
11973 packages. The general syntax is:
11976 guix graph @var{options} @var{package}@dots{}
11979 For example, the following command generates a PDF file representing the
11980 package DAG for the GNU@tie{}Core Utilities, showing its build-time
11984 guix graph coreutils | dot -Tpdf > dag.pdf
11987 The output looks like this:
11989 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
11991 Nice little graph, no?
11993 You may find it more pleasant to navigate the graph interactively with
11994 @command{xdot} (from the @code{xdot} package):
11997 guix graph coreutils | xdot -
12000 But there is more than one graph! The one above is concise: it is the
12001 graph of package objects, omitting implicit inputs such as GCC, libc,
12002 grep, etc. It is often useful to have such a concise graph, but
12003 sometimes one may want to see more details. @command{guix graph} supports
12004 several types of graphs, allowing you to choose the level of detail:
12008 This is the default type used in the example above. It shows the DAG of
12009 package objects, excluding implicit dependencies. It is concise, but
12010 filters out many details.
12012 @item reverse-package
12013 This shows the @emph{reverse} DAG of packages. For example:
12016 guix graph --type=reverse-package ocaml
12019 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
12020 you are also interested in cases where OCaml is an implicit dependency, see
12021 @code{reverse-bag} below).
12023 Note that for core packages this can yield huge graphs. If all you want
12024 is to know the number of packages that depend on a given package, use
12025 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
12026 @option{--list-dependent}}).
12029 This is the package DAG, @emph{including} implicit inputs.
12031 For instance, the following command:
12034 guix graph --type=bag-emerged coreutils
12037 ...@: yields this bigger graph:
12039 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
12041 At the bottom of the graph, we see all the implicit inputs of
12042 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
12044 Now, note that the dependencies of these implicit inputs---that is, the
12045 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
12046 here, for conciseness.
12049 Similar to @code{bag-emerged}, but this time including all the bootstrap
12052 @item bag-with-origins
12053 Similar to @code{bag}, but also showing origins and their dependencies.
12056 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
12057 it also takes implicit dependencies into account. For example:
12060 guix graph -t reverse-bag dune
12064 ...@: yields the graph of all packages that depend on Dune, directly or
12065 indirectly. Since Dune is an @emph{implicit} dependency of many packages
12066 @i{via} @code{dune-build-system}, this shows a large number of packages,
12067 whereas @code{reverse-package} would show very few if any.
12070 This is the most detailed representation: It shows the DAG of
12071 derivations (@pxref{Derivations}) and plain store items. Compared to
12072 the above representation, many additional nodes are visible, including
12073 build scripts, patches, Guile modules, etc.
12075 For this type of graph, it is also possible to pass a @file{.drv} file
12076 name instead of a package name, as in:
12079 guix graph -t derivation `guix system build -d my-config.scm`
12083 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
12084 For example, the following command shows the graph for the package
12085 module that defines the @code{guile} package:
12088 guix graph -t module guile | xdot -
12092 All the types above correspond to @emph{build-time dependencies}. The
12093 following graph type represents the @emph{run-time dependencies}:
12097 This is the graph of @dfn{references} of a package output, as returned
12098 by @command{guix gc --references} (@pxref{Invoking guix gc}).
12100 If the given package output is not available in the store, @command{guix
12101 graph} attempts to obtain dependency information from substitutes.
12103 Here you can also pass a store file name instead of a package name. For
12104 example, the command below produces the reference graph of your profile
12105 (which can be big!):
12108 guix graph -t references `readlink -f ~/.guix-profile`
12112 This is the graph of the @dfn{referrers} of a store item, as returned by
12113 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
12115 This relies exclusively on local information from your store. For
12116 instance, let us suppose that the current Inkscape is available in 10
12117 profiles on your machine; @command{guix graph -t referrers inkscape}
12118 will show a graph rooted at Inkscape and with those 10 profiles linked
12121 It can help determine what is preventing a store item from being garbage
12126 @cindex shortest path, between packages
12127 Often, the graph of the package you are interested in does not fit on
12128 your screen, and anyway all you want to know is @emph{why} that package
12129 actually depends on some seemingly unrelated package. The
12130 @option{--path} option instructs @command{guix graph} to display the
12131 shortest path between two packages (or derivations, or store items,
12135 $ guix graph --path emacs libunistring
12138 libunistring@@0.9.10
12139 $ guix graph --path -t derivation emacs libunistring
12140 /gnu/store/@dots{}-emacs-26.3.drv
12141 /gnu/store/@dots{}-mailutils-3.9.drv
12142 /gnu/store/@dots{}-libunistring-0.9.10.drv
12143 $ guix graph --path -t references emacs libunistring
12144 /gnu/store/@dots{}-emacs-26.3
12145 /gnu/store/@dots{}-libidn2-2.2.0
12146 /gnu/store/@dots{}-libunistring-0.9.10
12149 The available options are the following:
12152 @item --type=@var{type}
12153 @itemx -t @var{type}
12154 Produce a graph output of @var{type}, where @var{type} must be one of
12155 the values listed above.
12158 List the supported graph types.
12160 @item --backend=@var{backend}
12161 @itemx -b @var{backend}
12162 Produce a graph using the selected @var{backend}.
12164 @item --list-backends
12165 List the supported graph backends.
12167 Currently, the available backends are Graphviz and d3.js.
12170 Display the shortest path between two nodes of the type specified by
12171 @option{--type}. The example below shows the shortest path between
12172 @code{libreoffice} and @code{llvm} according to the references of
12173 @code{libreoffice}:
12176 $ guix graph --path -t references libreoffice llvm
12177 /gnu/store/@dots{}-libreoffice-6.4.2.2
12178 /gnu/store/@dots{}-libepoxy-1.5.4
12179 /gnu/store/@dots{}-mesa-19.3.4
12180 /gnu/store/@dots{}-llvm-9.0.1
12183 @item --expression=@var{expr}
12184 @itemx -e @var{expr}
12185 Consider the package @var{expr} evaluates to.
12187 This is useful to precisely refer to a package, as in this example:
12190 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
12193 @item --system=@var{system}
12194 @itemx -s @var{system}
12195 Display the graph for @var{system}---e.g., @code{i686-linux}.
12197 The package dependency graph is largely architecture-independent, but there
12198 are some architecture-dependent bits that this option allows you to visualize.
12200 @item --load-path=@var{directory}
12201 @itemx -L @var{directory}
12202 Add @var{directory} to the front of the package module search path
12203 (@pxref{Package Modules}).
12205 This allows users to define their own packages and make them visible to
12206 the command-line tools.
12209 On top of that, @command{guix graph} supports all the usual package
12210 transformation options (@pxref{Package Transformation Options}). This
12211 makes it easy to view the effect of a graph-rewriting transformation
12212 such as @option{--with-input}. For example, the command below outputs
12213 the graph of @code{git} once @code{openssl} has been replaced by
12214 @code{libressl} everywhere in the graph:
12217 guix graph git --with-input=openssl=libressl
12220 So many possibilities, so much fun!
12222 @node Invoking guix publish
12223 @section Invoking @command{guix publish}
12225 @cindex @command{guix publish}
12226 The purpose of @command{guix publish} is to enable users to easily share
12227 their store with others, who can then use it as a substitute server
12228 (@pxref{Substitutes}).
12230 When @command{guix publish} runs, it spawns an HTTP server which allows
12231 anyone with network access to obtain substitutes from it. This means
12232 that any machine running Guix can also act as if it were a build farm,
12233 since the HTTP interface is compatible with Cuirass, the software behind
12234 the @code{@value{SUBSTITUTE-SERVER}} build farm.
12236 For security, each substitute is signed, allowing recipients to check
12237 their authenticity and integrity (@pxref{Substitutes}). Because
12238 @command{guix publish} uses the signing key of the system, which is only
12239 readable by the system administrator, it must be started as root; the
12240 @option{--user} option makes it drop root privileges early on.
12242 The signing key pair must be generated before @command{guix publish} is
12243 launched, using @command{guix archive --generate-key} (@pxref{Invoking
12246 When the @option{--advertise} option is passed, the server advertises
12247 its availability on the local network using multicast DNS (mDNS) and DNS
12248 service discovery (DNS-SD), currently @i{via} Guile-Avahi (@pxref{Top,,,
12249 guile-avahi, Using Avahi in Guile Scheme Programs}).
12251 The general syntax is:
12254 guix publish @var{options}@dots{}
12257 Running @command{guix publish} without any additional arguments will
12258 spawn an HTTP server on port 8080:
12264 Once a publishing server has been authorized, the daemon may download
12265 substitutes from it. @xref{Getting Substitutes from Other Servers}.
12267 By default, @command{guix publish} compresses archives on the fly as it
12268 serves them. This ``on-the-fly'' mode is convenient in that it requires
12269 no setup and is immediately available. However, when serving lots of
12270 clients, we recommend using the @option{--cache} option, which enables
12271 caching of the archives before they are sent to clients---see below for
12272 details. The @command{guix weather} command provides a handy way to
12273 check what a server provides (@pxref{Invoking guix weather}).
12275 As a bonus, @command{guix publish} also serves as a content-addressed
12276 mirror for source files referenced in @code{origin} records
12277 (@pxref{origin Reference}). For instance, assuming @command{guix
12278 publish} is running on @code{example.org}, the following URL returns the
12279 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
12280 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
12283 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
12286 Obviously, these URLs only work for files that are in the store; in
12287 other cases, they return 404 (``Not Found'').
12289 @cindex build logs, publication
12290 Build logs are available from @code{/log} URLs like:
12293 http://example.org/log/gwspk@dots{}-guile-2.2.3
12297 When @command{guix-daemon} is configured to save compressed build logs,
12298 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
12299 URLs return the compressed log as-is, with an appropriate
12300 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
12301 running @command{guix-daemon} with @option{--log-compression=gzip} since
12302 Web browsers can automatically decompress it, which is not the case with
12305 The following options are available:
12308 @item --port=@var{port}
12309 @itemx -p @var{port}
12310 Listen for HTTP requests on @var{port}.
12312 @item --listen=@var{host}
12313 Listen on the network interface for @var{host}. The default is to
12314 accept connections from any interface.
12316 @item --user=@var{user}
12317 @itemx -u @var{user}
12318 Change privileges to @var{user} as soon as possible---i.e., once the
12319 server socket is open and the signing key has been read.
12321 @item --compression[=@var{method}[:@var{level}]]
12322 @itemx -C [@var{method}[:@var{level}]]
12323 Compress data using the given @var{method} and @var{level}. @var{method} is
12324 one of @code{lzip} and @code{gzip}; when @var{method} is omitted, @code{gzip}
12327 When @var{level} is zero, disable compression. The range 1 to 9 corresponds
12328 to different compression levels: 1 is the fastest, and 9 is the best
12329 (CPU-intensive). The default is 3.
12331 Usually, @code{lzip} compresses noticeably better than @code{gzip} for a small
12332 increase in CPU usage; see
12333 @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip Web
12336 Unless @option{--cache} is used, compression occurs on the fly and
12337 the compressed streams are not
12338 cached. Thus, to reduce load on the machine that runs @command{guix
12339 publish}, it may be a good idea to choose a low compression level, to
12340 run @command{guix publish} behind a caching proxy, or to use
12341 @option{--cache}. Using @option{--cache} has the advantage that it
12342 allows @command{guix publish} to add @code{Content-Length} HTTP header
12345 This option can be repeated, in which case every substitute gets compressed
12346 using all the selected methods, and all of them are advertised. This is
12347 useful when users may not support all the compression methods: they can select
12348 the one they support.
12350 @item --cache=@var{directory}
12351 @itemx -c @var{directory}
12352 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
12353 and only serve archives that are in cache.
12355 When this option is omitted, archives and meta-data are created
12356 on-the-fly. This can reduce the available bandwidth, especially when
12357 compression is enabled, since this may become CPU-bound. Another
12358 drawback of the default mode is that the length of archives is not known
12359 in advance, so @command{guix publish} does not add a
12360 @code{Content-Length} HTTP header to its responses, which in turn
12361 prevents clients from knowing the amount of data being downloaded.
12363 Conversely, when @option{--cache} is used, the first request for a store
12364 item (@i{via} a @code{.narinfo} URL) triggers a
12365 background process to @dfn{bake} the archive---computing its
12366 @code{.narinfo} and compressing the archive, if needed. Once the
12367 archive is cached in @var{directory}, subsequent requests succeed and
12368 are served directly from the cache, which guarantees that clients get
12369 the best possible bandwidth.
12371 That first @code{.narinfo} request nonetheless returns 200, provided the
12372 requested store item is ``small enough'', below the cache bypass
12373 threshold---see @option{--cache-bypass-threshold} below. That way,
12374 clients do not have to wait until the archive is baked. For larger
12375 store items, the first @code{.narinfo} request returns 404, meaning that
12376 clients have to wait until the archive is baked.
12378 The ``baking'' process is performed by worker threads. By default, one
12379 thread per CPU core is created, but this can be customized. See
12380 @option{--workers} below.
12382 When @option{--ttl} is used, cached entries are automatically deleted
12383 when they have expired.
12385 @item --workers=@var{N}
12386 When @option{--cache} is used, request the allocation of @var{N} worker
12387 threads to ``bake'' archives.
12389 @item --ttl=@var{ttl}
12390 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
12391 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
12392 days, @code{1m} means 1 month, and so on.
12394 This allows the user's Guix to keep substitute information in cache for
12395 @var{ttl}. However, note that @code{guix publish} does not itself
12396 guarantee that the store items it provides will indeed remain available
12397 for as long as @var{ttl}.
12399 Additionally, when @option{--cache} is used, cached entries that have
12400 not been accessed for @var{ttl} and that no longer have a corresponding
12401 item in the store, may be deleted.
12403 @item --cache-bypass-threshold=@var{size}
12404 When used in conjunction with @option{--cache}, store items smaller than
12405 @var{size} are immediately available, even when they are not yet in
12406 cache. @var{size} is a size in bytes, or it can be suffixed by @code{M}
12407 for megabytes and so on. The default is @code{10M}.
12409 ``Cache bypass'' allows you to reduce the publication delay for clients
12410 at the expense of possibly additional I/O and CPU use on the server
12411 side: depending on the client access patterns, those store items can end
12412 up being baked several times until a copy is available in cache.
12414 Increasing the threshold may be useful for sites that have few users, or
12415 to guarantee that users get substitutes even for store items that are
12418 @item --nar-path=@var{path}
12419 Use @var{path} as the prefix for the URLs of ``nar'' files
12420 (@pxref{Invoking guix archive, normalized archives}).
12422 By default, nars are served at a URL such as
12423 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
12424 change the @code{/nar} part to @var{path}.
12426 @item --public-key=@var{file}
12427 @itemx --private-key=@var{file}
12428 Use the specific @var{file}s as the public/private key pair used to sign
12429 the store items being published.
12431 The files must correspond to the same key pair (the private key is used
12432 for signing and the public key is merely advertised in the signature
12433 metadata). They must contain keys in the canonical s-expression format
12434 as produced by @command{guix archive --generate-key} (@pxref{Invoking
12435 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
12436 @file{/etc/guix/signing-key.sec} are used.
12438 @item --repl[=@var{port}]
12439 @itemx -r [@var{port}]
12440 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
12441 Reference Manual}) on @var{port} (37146 by default). This is used
12442 primarily for debugging a running @command{guix publish} server.
12445 Enabling @command{guix publish} on Guix System is a one-liner: just
12446 instantiate a @code{guix-publish-service-type} service in the @code{services} field
12447 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
12448 @code{guix-publish-service-type}}).
12450 If you are instead running Guix on a ``foreign distro'', follow these
12455 If your host distro uses the systemd init system:
12458 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
12459 /etc/systemd/system/
12460 # systemctl start guix-publish && systemctl enable guix-publish
12464 If your host distro uses the Upstart init system:
12467 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
12468 # start guix-publish
12472 Otherwise, proceed similarly with your distro's init system.
12475 @node Invoking guix challenge
12476 @section Invoking @command{guix challenge}
12478 @cindex reproducible builds
12479 @cindex verifiable builds
12480 @cindex @command{guix challenge}
12482 Do the binaries provided by this server really correspond to the source
12483 code it claims to build? Is a package build process deterministic?
12484 These are the questions the @command{guix challenge} command attempts to
12487 The former is obviously an important question: Before using a substitute
12488 server (@pxref{Substitutes}), one had better @emph{verify} that it
12489 provides the right binaries, and thus @emph{challenge} it. The latter
12490 is what enables the former: If package builds are deterministic, then
12491 independent builds of the package should yield the exact same result,
12492 bit for bit; if a server provides a binary different from the one
12493 obtained locally, it may be either corrupt or malicious.
12495 We know that the hash that shows up in @file{/gnu/store} file names is
12496 the hash of all the inputs of the process that built the file or
12497 directory---compilers, libraries, build scripts,
12498 etc. (@pxref{Introduction}). Assuming deterministic build processes,
12499 one store file name should map to exactly one build output.
12500 @command{guix challenge} checks whether there is, indeed, a single
12501 mapping by comparing the build outputs of several independent builds of
12502 any given store item.
12504 The command output looks like this:
12507 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
12508 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
12509 updating list of substitutes from 'https://guix.example.org'... 100.0%
12510 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
12511 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
12512 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
12513 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
12515 /lib/libcrypto.so.1.1
12518 /gnu/store/@dots{}-git-2.5.0 contents differ:
12519 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
12520 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
12521 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
12523 /libexec/git-core/git-fsck
12525 /gnu/store/@dots{}-pius-2.1.1 contents differ:
12526 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
12527 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
12528 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
12530 /share/man/man1/pius.1.gz
12534 6,406 store items were analyzed:
12535 - 4,749 (74.1%) were identical
12536 - 525 (8.2%) differed
12537 - 1,132 (17.7%) were inconclusive
12541 In this example, @command{guix challenge} first scans the store to
12542 determine the set of locally-built derivations---as opposed to store
12543 items that were downloaded from a substitute server---and then queries
12544 all the substitute servers. It then reports those store items for which
12545 the servers obtained a result different from the local build.
12547 @cindex non-determinism, in package builds
12548 As an example, @code{guix.example.org} always gets a different answer.
12549 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
12550 case of Git. This might indicate that the build process of Git is
12551 non-deterministic, meaning that its output varies as a function of
12552 various things that Guix does not fully control, in spite of building
12553 packages in isolated environments (@pxref{Features}). Most common
12554 sources of non-determinism include the addition of timestamps in build
12555 results, the inclusion of random numbers, and directory listings sorted
12556 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
12559 To find out what is wrong with this Git binary, the easiest approach is
12563 guix challenge git \
12564 --diff=diffoscope \
12565 --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
12568 This automatically invokes @command{diffoscope}, which displays detailed
12569 information about files that differ.
12571 Alternatively, we can do something along these lines (@pxref{Invoking guix
12575 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-git-2.5.0 \
12576 | lzip -d | guix archive -x /tmp/git
12577 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
12580 This command shows the difference between the files resulting from the
12581 local build, and the files resulting from the build on
12582 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
12583 diffutils, Comparing and Merging Files}). The @command{diff} command
12584 works great for text files. When binary files differ, a better option
12585 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
12586 visualize differences for all kinds of files.
12588 Once you have done that work, you can tell whether the differences are due
12589 to a non-deterministic build process or to a malicious server. We try
12590 hard to remove sources of non-determinism in packages to make it easier
12591 to verify substitutes, but of course, this is a process that
12592 involves not just Guix, but a large part of the free software community.
12593 In the meantime, @command{guix challenge} is one tool to help address
12596 If you are writing packages for Guix, you are encouraged to check
12597 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
12598 same build result as you did with:
12601 $ guix challenge @var{package}
12605 where @var{package} is a package specification such as
12606 @code{guile@@2.0} or @code{glibc:debug}.
12608 The general syntax is:
12611 guix challenge @var{options} [@var{packages}@dots{}]
12614 When a difference is found between the hash of a locally-built item and
12615 that of a server-provided substitute, or among substitutes provided by
12616 different servers, the command displays it as in the example above and
12617 its exit code is 2 (other non-zero exit codes denote other kinds of
12620 The one option that matters is:
12624 @item --substitute-urls=@var{urls}
12625 Consider @var{urls} the whitespace-separated list of substitute source
12626 URLs to compare to.
12628 @item --diff=@var{mode}
12629 Upon mismatches, show differences according to @var{mode}, one of:
12632 @item @code{simple} (the default)
12633 Show the list of files that differ.
12635 @item @code{diffoscope}
12636 @itemx @var{command}
12637 Invoke @uref{https://diffoscope.org/, Diffoscope}, passing it
12638 two directories whose contents do not match.
12640 When @var{command} is an absolute file name, run @var{command} instead
12644 Do not show further details about the differences.
12647 Thus, unless @option{--diff=none} is passed, @command{guix challenge}
12648 downloads the store items from the given substitute servers so that it
12653 Show details about matches (identical contents) in addition to
12654 information about mismatches.
12658 @node Invoking guix copy
12659 @section Invoking @command{guix copy}
12661 @cindex copy, of store items, over SSH
12662 @cindex SSH, copy of store items
12663 @cindex sharing store items across machines
12664 @cindex transferring store items across machines
12665 The @command{guix copy} command copies items from the store of one
12666 machine to that of another machine over a secure shell (SSH)
12667 connection@footnote{This command is available only when Guile-SSH was
12668 found. @xref{Requirements}, for details.}. For example, the following
12669 command copies the @code{coreutils} package, the user's profile, and all
12670 their dependencies over to @var{host}, logged in as @var{user}:
12673 guix copy --to=@var{user}@@@var{host} \
12674 coreutils `readlink -f ~/.guix-profile`
12677 If some of the items to be copied are already present on @var{host},
12678 they are not actually sent.
12680 The command below retrieves @code{libreoffice} and @code{gimp} from
12681 @var{host}, assuming they are available there:
12684 guix copy --from=@var{host} libreoffice gimp
12687 The SSH connection is established using the Guile-SSH client, which is
12688 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
12689 @file{~/.ssh/config}, and uses the SSH agent for authentication.
12691 The key used to sign items that are sent must be accepted by the remote
12692 machine. Likewise, the key used by the remote machine to sign items you
12693 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
12694 own daemon. @xref{Invoking guix archive}, for more information about
12695 store item authentication.
12697 The general syntax is:
12700 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
12703 You must always specify one of the following options:
12706 @item --to=@var{spec}
12707 @itemx --from=@var{spec}
12708 Specify the host to send to or receive from. @var{spec} must be an SSH
12709 spec such as @code{example.org}, @code{charlie@@example.org}, or
12710 @code{charlie@@example.org:2222}.
12713 The @var{items} can be either package names, such as @code{gimp}, or
12714 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
12716 When specifying the name of a package to send, it is first built if
12717 needed, unless @option{--dry-run} was specified. Common build options
12718 are supported (@pxref{Common Build Options}).
12721 @node Invoking guix container
12722 @section Invoking @command{guix container}
12724 @cindex @command{guix container}
12726 As of version @value{VERSION}, this tool is experimental. The interface
12727 is subject to radical change in the future.
12730 The purpose of @command{guix container} is to manipulate processes
12731 running within an isolated environment, commonly known as a
12732 ``container'', typically created by the @command{guix environment}
12733 (@pxref{Invoking guix environment}) and @command{guix system container}
12734 (@pxref{Invoking guix system}) commands.
12736 The general syntax is:
12739 guix container @var{action} @var{options}@dots{}
12742 @var{action} specifies the operation to perform with a container, and
12743 @var{options} specifies the context-specific arguments for the action.
12745 The following actions are available:
12749 Execute a command within the context of a running container.
12754 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
12757 @var{pid} specifies the process ID of the running container.
12758 @var{program} specifies an executable file name within the root file
12759 system of the container. @var{arguments} are the additional options that
12760 will be passed to @var{program}.
12762 The following command launches an interactive login shell inside a
12763 Guix system container, started by @command{guix system container}, and whose
12764 process ID is 9001:
12767 guix container exec 9001 /run/current-system/profile/bin/bash --login
12770 Note that the @var{pid} cannot be the parent process of a container. It
12771 must be PID 1 of the container or one of its child processes.
12775 @node Invoking guix weather
12776 @section Invoking @command{guix weather}
12778 Occasionally you're grumpy because substitutes are lacking and you end
12779 up building packages by yourself (@pxref{Substitutes}). The
12780 @command{guix weather} command reports on substitute availability on the
12781 specified servers so you can have an idea of whether you'll be grumpy
12782 today. It can sometimes be useful info as a user, but it is primarily
12783 useful to people running @command{guix publish} (@pxref{Invoking guix
12786 @cindex statistics, for substitutes
12787 @cindex availability of substitutes
12788 @cindex substitute availability
12789 @cindex weather, substitute availability
12790 Here's a sample run:
12793 $ guix weather --substitute-urls=https://guix.example.org
12794 computing 5,872 package derivations for x86_64-linux...
12795 looking for 6,128 store items on https://guix.example.org..
12796 updating list of substitutes from 'https://guix.example.org'... 100.0%
12797 https://guix.example.org
12798 43.4% substitutes available (2,658 out of 6,128)
12799 7,032.5 MiB of nars (compressed)
12800 19,824.2 MiB on disk (uncompressed)
12801 0.030 seconds per request (182.9 seconds in total)
12802 33.5 requests per second
12804 9.8% (342 out of 3,470) of the missing items are queued
12806 x86_64-linux: 518 (59.7%)
12807 i686-linux: 221 (25.5%)
12808 aarch64-linux: 128 (14.8%)
12809 build rate: 23.41 builds per hour
12810 x86_64-linux: 11.16 builds per hour
12811 i686-linux: 6.03 builds per hour
12812 aarch64-linux: 6.41 builds per hour
12815 @cindex continuous integration, statistics
12816 As you can see, it reports the fraction of all the packages for which
12817 substitutes are available on the server---regardless of whether
12818 substitutes are enabled, and regardless of whether this server's signing
12819 key is authorized. It also reports the size of the compressed archives
12820 (``nars'') provided by the server, the size the corresponding store
12821 items occupy in the store (assuming deduplication is turned off), and
12822 the server's throughput. The second part gives continuous integration
12823 (CI) statistics, if the server supports it. In addition, using the
12824 @option{--coverage} option, @command{guix weather} can list ``important''
12825 package substitutes missing on the server (see below).
12827 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
12828 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
12829 challenge}, it ignores signatures on those substitutes, which is
12830 innocuous since the command only gathers statistics and cannot install
12833 The general syntax is:
12836 guix weather @var{options}@dots{} [@var{packages}@dots{}]
12839 When @var{packages} is omitted, @command{guix weather} checks the availability
12840 of substitutes for @emph{all} the packages, or for those specified with
12841 @option{--manifest}; otherwise it only considers the specified packages. It
12842 is also possible to query specific system types with @option{--system}.
12843 @command{guix weather} exits with a non-zero code when the fraction of
12844 available substitutes is below 100%.
12846 The available options are listed below.
12849 @item --substitute-urls=@var{urls}
12850 @var{urls} is the space-separated list of substitute server URLs to
12851 query. When this option is omitted, the default set of substitute
12852 servers is queried.
12854 @item --system=@var{system}
12855 @itemx -s @var{system}
12856 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
12857 option can be repeated, in which case @command{guix weather} will query
12858 substitutes for several system types.
12860 @item --manifest=@var{file}
12861 Instead of querying substitutes for all the packages, only ask for those
12862 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
12863 with the @code{-m} option of @command{guix package} (@pxref{Invoking
12866 This option can be repeated several times, in which case the manifests
12869 @item --coverage[=@var{count}]
12870 @itemx -c [@var{count}]
12871 Report on substitute coverage for packages: list packages with at least
12872 @var{count} dependents (zero by default) for which substitutes are
12873 unavailable. Dependent packages themselves are not listed: if @var{b} depends
12874 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
12875 @var{b} usually lacks substitutes as well. The result looks like this:
12878 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
12879 computing 8,983 package derivations for x86_64-linux...
12880 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
12881 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
12882 @value{SUBSTITUTE-URL}
12883 64.7% substitutes available (6,047 out of 9,343)
12885 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
12886 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
12887 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
12888 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
12892 What this example shows is that @code{kcoreaddons} and presumably the 58
12893 packages that depend on it have no substitutes at @code{ci.guix.info};
12894 likewise for @code{qgpgme} and the 46 packages that depend on it.
12896 If you are a Guix developer, or if you are taking care of this build farm,
12897 you'll probably want to have a closer look at these packages: they may simply
12900 @item --display-missing
12901 Display the list of store items for which substitutes are missing.
12904 @node Invoking guix processes
12905 @section Invoking @command{guix processes}
12907 The @command{guix processes} command can be useful to developers and system
12908 administrators, especially on multi-user machines and on build farms: it lists
12909 the current sessions (connections to the daemon), as well as information about
12910 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
12911 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
12912 listed.}. Here's an example of the information it returns:
12915 $ sudo guix processes
12918 ClientCommand: guix environment --ad-hoc python
12922 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
12926 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
12927 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
12928 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
12929 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
12931 ChildCommand: guix offload x86_64-linux 7200 1 28800
12933 ChildCommand: guix offload x86_64-linux 7200 1 28800
12935 ChildCommand: guix offload x86_64-linux 7200 1 28800
12938 In this example we see that @command{guix-daemon} has three clients:
12939 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
12940 integration tool; their process identifier (PID) is given by the
12941 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
12942 @command{guix-daemon} sub-process of this particular session.
12944 The @code{LockHeld} fields show which store items are currently locked
12945 by this session, which corresponds to store items being built or
12946 substituted (the @code{LockHeld} field is not displayed when
12947 @command{guix processes} is not running as root). Last, by looking at
12948 the @code{ChildPID} and @code{ChildCommand} fields, we understand that
12949 these three builds are being offloaded (@pxref{Daemon Offload Setup}).
12951 The output is in Recutils format so we can use the handy @command{recsel}
12952 command to select sessions of interest (@pxref{Selection Expressions,,,
12953 recutils, GNU recutils manual}). As an example, the command shows the command
12954 line and PID of the client that triggered the build of a Perl package:
12957 $ sudo guix processes | \
12958 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
12960 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
12963 Additional options are listed below.
12966 @item --format=@var{format}
12967 @itemx -f @var{format}
12968 Produce output in the specified @var{format}, one of:
12972 The default option. It outputs a set of Session recutils records
12973 that include each @code{ChildProcess} as a field.
12976 Normalize the output records into record sets (@pxref{Record Sets,,,
12977 recutils, GNU recutils manual}). Normalizing into record sets allows
12978 joins across record types. The example below lists the PID of each
12979 @code{ChildProcess} and the associated PID for @code{Session} that
12980 spawned the @code{ChildProcess} where the @code{Session} was started
12981 using @command{guix build}.
12984 $ guix processes --format=normalized | \
12988 -p Session.PID,PID \
12989 -e 'Session.ClientCommand ~ "guix build"'
13002 @node System Configuration
13003 @chapter System Configuration
13005 @cindex system configuration
13006 Guix System supports a consistent whole-system configuration
13007 mechanism. By that we mean that all aspects of the global system
13008 configuration---such as the available system services, timezone and
13009 locale settings, user accounts---are declared in a single place. Such
13010 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
13012 One of the advantages of putting all the system configuration under the
13013 control of Guix is that it supports transactional system upgrades, and
13014 makes it possible to roll back to a previous system instantiation,
13015 should something go wrong with the new one (@pxref{Features}). Another
13016 advantage is that it makes it easy to replicate the exact same configuration
13017 across different machines, or at different points in time, without
13018 having to resort to additional administration tools layered on top of
13019 the own tools of the system.
13020 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
13022 This section describes this mechanism. First we focus on the system
13023 administrator's viewpoint---explaining how the system is configured and
13024 instantiated. Then we show how this mechanism can be extended, for
13025 instance to support new system services.
13028 * Using the Configuration System:: Customizing your GNU system.
13029 * operating-system Reference:: Detail of operating-system declarations.
13030 * File Systems:: Configuring file system mounts.
13031 * Mapped Devices:: Block device extra processing.
13032 * User Accounts:: Specifying user accounts.
13033 * Keyboard Layout:: How the system interprets key strokes.
13034 * Locales:: Language and cultural convention settings.
13035 * Services:: Specifying system services.
13036 * Setuid Programs:: Programs running with root privileges.
13037 * X.509 Certificates:: Authenticating HTTPS servers.
13038 * Name Service Switch:: Configuring libc's name service switch.
13039 * Initial RAM Disk:: Linux-Libre bootstrapping.
13040 * Bootloader Configuration:: Configuring the boot loader.
13041 * Invoking guix system:: Instantiating a system configuration.
13042 * Invoking guix deploy:: Deploying a system configuration to a remote host.
13043 * Running Guix in a VM:: How to run Guix System in a virtual machine.
13044 * Defining Services:: Adding new service definitions.
13047 @node Using the Configuration System
13048 @section Using the Configuration System
13050 The operating system is configured by providing an
13051 @code{operating-system} declaration in a file that can then be passed to
13052 the @command{guix system} command (@pxref{Invoking guix system}). A
13053 simple setup, with the default system services, the default Linux-Libre
13054 kernel, initial RAM disk, and boot loader looks like this:
13056 @findex operating-system
13058 @include os-config-bare-bones.texi
13061 This example should be self-describing. Some of the fields defined
13062 above, such as @code{host-name} and @code{bootloader}, are mandatory.
13063 Others, such as @code{packages} and @code{services}, can be omitted, in
13064 which case they get a default value.
13066 Below we discuss the effect of some of the most important fields
13067 (@pxref{operating-system Reference}, for details about all the available
13068 fields), and how to @dfn{instantiate} the operating system using
13069 @command{guix system}.
13071 @unnumberedsubsec Bootloader
13073 @cindex legacy boot, on Intel machines
13074 @cindex BIOS boot, on Intel machines
13077 The @code{bootloader} field describes the method that will be used to boot
13078 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
13079 mode, as in the example above. However, more recent machines rely instead on
13080 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
13081 the @code{bootloader} field should contain something along these lines:
13084 (bootloader-configuration
13085 (bootloader grub-efi-bootloader)
13086 (target "/boot/efi"))
13089 @xref{Bootloader Configuration}, for more information on the available
13090 configuration options.
13092 @unnumberedsubsec Globally-Visible Packages
13094 @vindex %base-packages
13095 The @code{packages} field lists packages that will be globally visible
13096 on the system, for all user accounts---i.e., in every user's @env{PATH}
13097 environment variable---in addition to the per-user profiles
13098 (@pxref{Invoking guix package}). The @code{%base-packages} variable
13099 provides all the tools one would expect for basic user and administrator
13100 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
13101 the GNU Zile lightweight text editor, @command{find}, @command{grep},
13102 etc. The example above adds GNU@tie{}Screen to those,
13103 taken from the @code{(gnu packages screen)}
13104 module (@pxref{Package Modules}). The
13105 @code{(list package output)} syntax can be used to add a specific output
13109 (use-modules (gnu packages))
13110 (use-modules (gnu packages dns))
13114 (packages (cons (list bind "utils")
13118 @findex specification->package
13119 Referring to packages by variable name, like @code{bind} above, has
13120 the advantage of being unambiguous; it also allows typos and such to be
13121 diagnosed right away as ``unbound variables''. The downside is that one
13122 needs to know which module defines which package, and to augment the
13123 @code{use-package-modules} line accordingly. To avoid that, one can use
13124 the @code{specification->package} procedure of the @code{(gnu packages)}
13125 module, which returns the best package for a given name or name and
13129 (use-modules (gnu packages))
13133 (packages (append (map specification->package
13134 '("tcpdump" "htop" "gnupg@@2.0"))
13138 @unnumberedsubsec System Services
13141 @vindex %base-services
13142 The @code{services} field lists @dfn{system services} to be made
13143 available when the system starts (@pxref{Services}).
13144 The @code{operating-system} declaration above specifies that, in
13145 addition to the basic services, we want the OpenSSH secure shell
13146 daemon listening on port 2222 (@pxref{Networking Services,
13147 @code{openssh-service-type}}). Under the hood,
13148 @code{openssh-service-type} arranges so that @command{sshd} is started with the
13149 right command-line options, possibly with supporting configuration files
13150 generated as needed (@pxref{Defining Services}).
13152 @cindex customization, of services
13153 @findex modify-services
13154 Occasionally, instead of using the base services as is, you will want to
13155 customize them. To do this, use @code{modify-services} (@pxref{Service
13156 Reference, @code{modify-services}}) to modify the list.
13158 For example, suppose you want to modify @code{guix-daemon} and Mingetty
13159 (the console log-in) in the @code{%base-services} list (@pxref{Base
13160 Services, @code{%base-services}}). To do that, you can write the
13161 following in your operating system declaration:
13164 (define %my-services
13165 ;; My very own list of services.
13166 (modify-services %base-services
13167 (guix-service-type config =>
13168 (guix-configuration
13170 ;; Fetch substitutes from example.org.
13172 (list "https://example.org/guix"
13173 "https://ci.guix.gnu.org"))))
13174 (mingetty-service-type config =>
13175 (mingetty-configuration
13177 ;; Automatially log in as "guest".
13178 (auto-login "guest")))))
13182 (services %my-services))
13185 This changes the configuration---i.e., the service parameters---of the
13186 @code{guix-service-type} instance, and that of all the
13187 @code{mingetty-service-type} instances in the @code{%base-services} list.
13188 Observe how this is accomplished: first, we arrange for the original
13189 configuration to be bound to the identifier @code{config} in the
13190 @var{body}, and then we write the @var{body} so that it evaluates to the
13191 desired configuration. In particular, notice how we use @code{inherit}
13192 to create a new configuration which has the same values as the old
13193 configuration, but with a few modifications.
13195 @cindex encrypted disk
13196 The configuration for a typical ``desktop'' usage, with an encrypted
13197 root partition, the X11 display
13198 server, GNOME and Xfce (users can choose which of these desktop
13199 environments to use at the log-in screen by pressing @kbd{F1}), network
13200 management, power management, and more, would look like this:
13203 @include os-config-desktop.texi
13206 A graphical system with a choice of lightweight window managers
13207 instead of full-blown desktop environments would look like this:
13210 @include os-config-lightweight-desktop.texi
13213 This example refers to the @file{/boot/efi} file system by its UUID,
13214 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
13215 as returned by the @command{blkid} command.
13217 @xref{Desktop Services}, for the exact list of services provided by
13218 @code{%desktop-services}. @xref{X.509 Certificates}, for background
13219 information about the @code{nss-certs} package that is used here.
13221 Again, @code{%desktop-services} is just a list of service objects. If
13222 you want to remove services from there, you can do so using the
13223 procedures for list filtering (@pxref{SRFI-1 Filtering and
13224 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
13225 following expression returns a list that contains all the services in
13226 @code{%desktop-services} minus the Avahi service:
13229 (remove (lambda (service)
13230 (eq? (service-kind service) avahi-service-type))
13234 @unnumberedsubsec Instantiating the System
13236 Assuming the @code{operating-system} declaration
13237 is stored in the @file{my-system-config.scm}
13238 file, the @command{guix system reconfigure my-system-config.scm} command
13239 instantiates that configuration, and makes it the default GRUB boot
13240 entry (@pxref{Invoking guix system}).
13242 The normal way to change the system configuration is by updating this
13243 file and re-running @command{guix system reconfigure}. One should never
13244 have to touch files in @file{/etc} or to run commands that modify the
13245 system state such as @command{useradd} or @command{grub-install}. In
13246 fact, you must avoid that since that would not only void your warranty
13247 but also prevent you from rolling back to previous versions of your
13248 system, should you ever need to.
13250 @cindex roll-back, of the operating system
13251 Speaking of roll-back, each time you run @command{guix system
13252 reconfigure}, a new @dfn{generation} of the system is created---without
13253 modifying or deleting previous generations. Old system generations get
13254 an entry in the bootloader boot menu, allowing you to boot them in case
13255 something went wrong with the latest generation. Reassuring, no? The
13256 @command{guix system list-generations} command lists the system
13257 generations available on disk. It is also possible to roll back the
13258 system via the commands @command{guix system roll-back} and
13259 @command{guix system switch-generation}.
13261 Although the @command{guix system reconfigure} command will not modify
13262 previous generations, you must take care when the current generation is not
13263 the latest (e.g., after invoking @command{guix system roll-back}), since
13264 the operation might overwrite a later generation (@pxref{Invoking guix
13267 @unnumberedsubsec The Programming Interface
13269 At the Scheme level, the bulk of an @code{operating-system} declaration
13270 is instantiated with the following monadic procedure (@pxref{The Store
13273 @deffn {Monadic Procedure} operating-system-derivation os
13274 Return a derivation that builds @var{os}, an @code{operating-system}
13275 object (@pxref{Derivations}).
13277 The output of the derivation is a single directory that refers to all
13278 the packages, configuration files, and other supporting files needed to
13279 instantiate @var{os}.
13282 This procedure is provided by the @code{(gnu system)} module. Along
13283 with @code{(gnu services)} (@pxref{Services}), this module contains the
13284 guts of Guix System. Make sure to visit it!
13287 @node operating-system Reference
13288 @section @code{operating-system} Reference
13290 This section summarizes all the options available in
13291 @code{operating-system} declarations (@pxref{Using the Configuration
13294 @deftp {Data Type} operating-system
13295 This is the data type representing an operating system configuration.
13296 By that, we mean all the global system configuration, not per-user
13297 configuration (@pxref{Using the Configuration System}).
13300 @item @code{kernel} (default: @code{linux-libre})
13301 The package object of the operating system kernel to
13302 use@footnote{Currently only the Linux-libre kernel is fully supported.
13303 Using GNU@tie{}mach with the GNU@tie{}Hurd is experimental and only
13304 available when building a virtual machine disk image.}.
13307 @item @code{hurd} (default: @code{#f})
13308 The package object of the Hurd to be started by the kernel. When this
13309 field is set, produce a GNU/Hurd operating system. In that case,
13310 @code{kernel} must also be set to the @code{gnumach} package---the
13311 microkernel the Hurd runs on.
13314 This feature is experimental and only supported for disk images.
13317 @item @code{kernel-loadable-modules} (default: '())
13318 A list of objects (usually packages) to collect loadable kernel modules
13319 from--e.g. @code{(list ddcci-driver-linux)}.
13321 @item @code{kernel-arguments} (default: @code{%default-kernel-arguments})
13322 List of strings or gexps representing additional arguments to pass on
13323 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
13325 @item @code{bootloader}
13326 The system bootloader configuration object. @xref{Bootloader Configuration}.
13329 This is the label (a string) as it appears in the bootloader's menu entry.
13330 The default label includes the kernel name and version.
13332 @item @code{keyboard-layout} (default: @code{#f})
13333 This field specifies the keyboard layout to use in the console. It can be
13334 either @code{#f}, in which case the default keyboard layout is used (usually
13335 US English), or a @code{<keyboard-layout>} record.
13337 This keyboard layout is in effect as soon as the kernel has booted. For
13338 instance, it is the keyboard layout in effect when you type a passphrase if
13339 your root file system is on a @code{luks-device-mapping} mapped device
13340 (@pxref{Mapped Devices}).
13343 This does @emph{not} specify the keyboard layout used by the bootloader, nor
13344 that used by the graphical display server. @xref{Bootloader Configuration},
13345 for information on how to specify the bootloader's keyboard layout. @xref{X
13346 Window}, for information on how to specify the keyboard layout used by the X
13350 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
13352 @cindex initial RAM disk
13353 The list of Linux kernel modules that need to be available in the
13354 initial RAM disk. @xref{Initial RAM Disk}.
13356 @item @code{initrd} (default: @code{base-initrd})
13357 A procedure that returns an initial RAM disk for the Linux
13358 kernel. This field is provided to support low-level customization and
13359 should rarely be needed for casual use. @xref{Initial RAM Disk}.
13361 @item @code{firmware} (default: @code{%base-firmware})
13363 List of firmware packages loadable by the operating system kernel.
13365 The default includes firmware needed for Atheros- and Broadcom-based
13366 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
13367 respectively). @xref{Hardware Considerations}, for more info on
13368 supported hardware.
13370 @item @code{host-name}
13373 @item @code{hosts-file}
13375 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
13376 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
13377 Reference Manual}). The default is a file with entries for
13378 @code{localhost} and @var{host-name}.
13380 @item @code{mapped-devices} (default: @code{'()})
13381 A list of mapped devices. @xref{Mapped Devices}.
13383 @item @code{file-systems}
13384 A list of file systems. @xref{File Systems}.
13386 @cindex swap devices
13388 @item @code{swap-devices} (default: @code{'()})
13389 A list of UUIDs, file system labels, or strings identifying devices or
13390 files to be used for ``swap
13391 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
13392 Manual}). Here are some examples:
13395 @item (list (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb"))
13396 Use the swap partition with the given UUID. You can learn the UUID of a
13397 Linux swap partition by running @command{swaplabel @var{device}}, where
13398 @var{device} is the @file{/dev} file name of that partition.
13400 @item (list (file-system-label "swap"))
13401 Use the partition with label @code{swap}. Again, the
13402 @command{swaplabel} command allows you to view and change the label of a
13403 Linux swap partition.
13405 @item (list "/swapfile")
13406 Use the file @file{/swapfile} as swap space.
13408 @item (list "/dev/sda3" "/dev/sdb2")
13409 Use the @file{/dev/sda3} and @file{/dev/sdb2} partitions as swap space.
13410 We recommend referring to swap devices by UUIDs or labels as shown above
13414 It is possible to specify a swap file in a file system on a mapped
13415 device (under @file{/dev/mapper}), provided that the necessary device
13416 mapping and file system are also specified. @xref{Mapped Devices} and
13417 @ref{File Systems}.
13419 @item @code{users} (default: @code{%base-user-accounts})
13420 @itemx @code{groups} (default: @code{%base-groups})
13421 List of user accounts and groups. @xref{User Accounts}.
13423 If the @code{users} list lacks a user account with UID@tie{}0, a
13424 ``root'' account with UID@tie{}0 is automatically added.
13426 @item @code{skeletons} (default: @code{(default-skeletons)})
13427 A list of target file name/file-like object tuples (@pxref{G-Expressions,
13428 file-like objects}). These are the skeleton files that will be added to
13429 the home directory of newly-created user accounts.
13431 For instance, a valid value may look like this:
13434 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
13435 (".guile" ,(plain-file "guile"
13436 "(use-modules (ice-9 readline))
13437 (activate-readline)")))
13440 @item @code{issue} (default: @code{%default-issue})
13441 A string denoting the contents of the @file{/etc/issue} file, which is
13442 displayed when users log in on a text console.
13444 @item @code{packages} (default: @code{%base-packages})
13445 A list of packages to be installed in the global profile, which is accessible
13446 at @file{/run/current-system/profile}. Each element is either a package
13447 variable or a package/output tuple. Here's a simple example of both:
13450 (cons* git ; the default "out" output
13451 (list git "send-email") ; another output of git
13452 %base-packages) ; the default set
13455 The default set includes core utilities and it is good practice to
13456 install non-core utilities in user profiles (@pxref{Invoking guix
13459 @item @code{timezone}
13460 A timezone identifying string---e.g., @code{"Europe/Paris"}.
13462 You can run the @command{tzselect} command to find out which timezone
13463 string corresponds to your region. Choosing an invalid timezone name
13464 causes @command{guix system} to fail.
13466 @item @code{locale} (default: @code{"en_US.utf8"})
13467 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
13468 Library Reference Manual}). @xref{Locales}, for more information.
13470 @item @code{locale-definitions} (default: @code{%default-locale-definitions})
13471 The list of locale definitions to be compiled and that may be used at
13472 run time. @xref{Locales}.
13474 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
13475 The list of GNU@tie{}libc packages whose locale data and tools are used
13476 to build the locale definitions. @xref{Locales}, for compatibility
13477 considerations that justify this option.
13479 @item @code{name-service-switch} (default: @code{%default-nss})
13480 Configuration of the libc name service switch (NSS)---a
13481 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
13484 @item @code{services} (default: @code{%base-services})
13485 A list of service objects denoting system services. @xref{Services}.
13487 @cindex essential services
13488 @item @code{essential-services} (default: ...)
13489 The list of ``essential services''---i.e., things like instances of
13490 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
13491 Reference}), which are derived from the operating system definition itself.
13492 As a user you should @emph{never} need to touch this field.
13494 @item @code{pam-services} (default: @code{(base-pam-services)})
13496 @cindex pluggable authentication modules
13497 Linux @dfn{pluggable authentication module} (PAM) services.
13498 @c FIXME: Add xref to PAM services section.
13500 @item @code{setuid-programs} (default: @code{%setuid-programs})
13501 List of string-valued G-expressions denoting setuid programs.
13502 @xref{Setuid Programs}.
13504 @item @code{sudoers-file} (default: @code{%sudoers-specification})
13505 @cindex sudoers file
13506 The contents of the @file{/etc/sudoers} file as a file-like object
13507 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
13509 This file specifies which users can use the @command{sudo} command, what
13510 they are allowed to do, and what privileges they may gain. The default
13511 is that only @code{root} and members of the @code{wheel} group may use
13516 @deffn {Scheme Syntax} this-operating-system
13517 When used in the @emph{lexical scope} of an operating system field definition,
13518 this identifier resolves to the operating system being defined.
13520 The example below shows how to refer to the operating system being defined in
13521 the definition of the @code{label} field:
13524 (use-modules (gnu) (guix))
13528 (label (package-full-name
13529 (operating-system-kernel this-operating-system))))
13532 It is an error to refer to @code{this-operating-system} outside an operating
13539 @section File Systems
13541 The list of file systems to be mounted is specified in the
13542 @code{file-systems} field of the operating system declaration
13543 (@pxref{Using the Configuration System}). Each file system is declared
13544 using the @code{file-system} form, like this:
13548 (mount-point "/home")
13549 (device "/dev/sda3")
13553 As usual, some of the fields are mandatory---those shown in the example
13554 above---while others can be omitted. These are described below.
13556 @deftp {Data Type} file-system
13557 Objects of this type represent file systems to be mounted. They
13558 contain the following members:
13562 This is a string specifying the type of the file system---e.g.,
13565 @item @code{mount-point}
13566 This designates the place where the file system is to be mounted.
13568 @item @code{device}
13569 This names the ``source'' of the file system. It can be one of three
13570 things: a file system label, a file system UUID, or the name of a
13571 @file{/dev} node. Labels and UUIDs offer a way to refer to file
13572 systems without having to hard-code their actual device
13573 name@footnote{Note that, while it is tempting to use
13574 @file{/dev/disk/by-uuid} and similar device names to achieve the same
13575 result, this is not recommended: These special device nodes are created
13576 by the udev daemon and may be unavailable at the time the device is
13579 @findex file-system-label
13580 File system labels are created using the @code{file-system-label}
13581 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
13582 plain strings. Here's an example of a file system referred to by its
13583 label, as shown by the @command{e2label} command:
13587 (mount-point "/home")
13589 (device (file-system-label "my-home")))
13593 UUIDs are converted from their string representation (as shown by the
13594 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
13595 @code{uuid} form expects 16-byte UUIDs as defined in
13596 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
13597 form of UUID used by the ext2 family of file systems and others, but it
13598 is different from ``UUIDs'' found in FAT file systems, for instance.},
13603 (mount-point "/home")
13605 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
13608 When the source of a file system is a mapped device (@pxref{Mapped
13609 Devices}), its @code{device} field @emph{must} refer to the mapped
13610 device name---e.g., @file{"/dev/mapper/root-partition"}.
13611 This is required so that
13612 the system knows that mounting the file system depends on having the
13613 corresponding device mapping established.
13615 @item @code{flags} (default: @code{'()})
13616 This is a list of symbols denoting mount flags. Recognized flags
13617 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
13618 access to special files), @code{no-suid} (ignore setuid and setgid
13619 bits), @code{no-atime} (do not update file access times),
13620 @code{strict-atime} (update file access time), @code{lazy-time} (only
13621 update time on the in-memory version of the file inode), and
13622 @code{no-exec} (disallow program execution).
13623 @xref{Mount-Unmount-Remount,,, libc, The GNU C Library Reference
13624 Manual}, for more information on these flags.
13626 @item @code{options} (default: @code{#f})
13627 This is either @code{#f}, or a string denoting mount options passed to
13628 the file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C
13629 Library Reference Manual}, for details and run @command{man 8 mount} for
13630 options for various file systems. Note that the
13631 @code{file-system-options->alist} and @code{alist->file-system-options}
13632 procedures from @code{(gnu system file-systems)} can be used to convert
13633 file system options given as an association list to the string
13634 representation, and vice-versa.
13636 @item @code{mount?} (default: @code{#t})
13637 This value indicates whether to automatically mount the file system when
13638 the system is brought up. When set to @code{#f}, the file system gets
13639 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
13640 is not automatically mounted.
13642 @item @code{needed-for-boot?} (default: @code{#f})
13643 This Boolean value indicates whether the file system is needed when
13644 booting. If that is true, then the file system is mounted when the
13645 initial RAM disk (initrd) is loaded. This is always the case, for
13646 instance, for the root file system.
13648 @item @code{check?} (default: @code{#t})
13649 This Boolean indicates whether the file system needs to be checked for
13650 errors before being mounted.
13652 @item @code{create-mount-point?} (default: @code{#f})
13653 When true, the mount point is created if it does not exist yet.
13655 @item @code{mount-may-fail?} (default: @code{#f})
13656 When true, this indicates that mounting this file system can fail but
13657 that should not be considered an error. This is useful in unusual
13658 cases; an example of this is @code{efivarfs}, a file system that can
13659 only be mounted on EFI/UEFI systems.
13661 @item @code{dependencies} (default: @code{'()})
13662 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
13663 representing file systems that must be mounted or mapped devices that
13664 must be opened before (and unmounted or closed after) this one.
13666 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
13667 a dependency of @file{/sys/fs/cgroup/cpu} and
13668 @file{/sys/fs/cgroup/memory}.
13670 Another example is a file system that depends on a mapped device, for
13671 example for an encrypted partition (@pxref{Mapped Devices}).
13675 @deffn {Scheme Procedure} file-system-label @var{str}
13676 This procedure returns an opaque file system label from @var{str}, a
13680 (file-system-label "home")
13681 @result{} #<file-system-label "home">
13684 File system labels are used to refer to file systems by label rather
13685 than by device name. See above for examples.
13688 The @code{(gnu system file-systems)} exports the following useful
13691 @defvr {Scheme Variable} %base-file-systems
13692 These are essential file systems that are required on normal systems,
13693 such as @code{%pseudo-terminal-file-system} and @code{%immutable-store} (see
13694 below). Operating system declarations should always contain at least
13698 @defvr {Scheme Variable} %pseudo-terminal-file-system
13699 This is the file system to be mounted as @file{/dev/pts}. It supports
13700 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
13701 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
13702 Manual}). Pseudo-terminals are used by terminal emulators such as
13706 @defvr {Scheme Variable} %shared-memory-file-system
13707 This file system is mounted as @file{/dev/shm} and is used to support
13708 memory sharing across processes (@pxref{Memory-mapped I/O,
13709 @code{shm_open},, libc, The GNU C Library Reference Manual}).
13712 @defvr {Scheme Variable} %immutable-store
13713 This file system performs a read-only ``bind mount'' of
13714 @file{/gnu/store}, making it read-only for all the users including
13715 @code{root}. This prevents against accidental modification by software
13716 running as @code{root} or by system administrators.
13718 The daemon itself is still able to write to the store: it remounts it
13719 read-write in its own ``name space.''
13722 @defvr {Scheme Variable} %binary-format-file-system
13723 The @code{binfmt_misc} file system, which allows handling of arbitrary
13724 executable file types to be delegated to user space. This requires the
13725 @code{binfmt.ko} kernel module to be loaded.
13728 @defvr {Scheme Variable} %fuse-control-file-system
13729 The @code{fusectl} file system, which allows unprivileged users to mount
13730 and unmount user-space FUSE file systems. This requires the
13731 @code{fuse.ko} kernel module to be loaded.
13734 The @code{(gnu system uuid)} module provides tools to deal with file
13735 system ``unique identifiers'' (UUIDs).
13737 @deffn {Scheme Procedure} uuid @var{str} [@var{type}]
13738 Return an opaque UUID (unique identifier) object of the given @var{type}
13739 (a symbol) by parsing @var{str} (a string):
13742 (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")
13743 @result{} #<<uuid> type: dce bv: @dots{}>
13745 (uuid "1234-ABCD" 'fat)
13746 @result{} #<<uuid> type: fat bv: @dots{}>
13749 @var{type} may be one of @code{dce}, @code{iso9660}, @code{fat},
13750 @code{ntfs}, or one of the commonly found synonyms for these.
13752 UUIDs are another way to unambiguously refer to file systems in
13753 operating system configuration. See the examples above.
13757 @node Btrfs file system
13758 @subsection Btrfs file system
13760 The Btrfs has special features, such as subvolumes, that merit being
13761 explained in more details. The following section attempts to cover
13762 basic as well as complex uses of a Btrfs file system with the Guix
13765 In its simplest usage, a Btrfs file system can be described, for
13770 (mount-point "/home")
13772 (device (file-system-label "my-home")))
13775 The example below is more complex, as it makes use of a Btrfs
13776 subvolume, named @code{rootfs}. The parent Btrfs file system is labeled
13777 @code{my-btrfs-pool}, and is located on an encrypted device (hence the
13778 dependency on @code{mapped-devices}):
13782 (device (file-system-label "my-btrfs-pool"))
13785 (options "subvol=rootfs")
13786 (dependencies mapped-devices))
13789 Some bootloaders, for example GRUB, only mount a Btrfs partition at its
13790 top level during the early boot, and rely on their configuration to
13791 refer to the correct subvolume path within that top level. The
13792 bootloaders operating in this way typically produce their configuration
13793 on a running system where the Btrfs partitions are already mounted and
13794 where the subvolume information is readily available. As an example,
13795 @command{grub-mkconfig}, the configuration generator command shipped
13796 with GRUB, reads @file{/proc/self/mountinfo} to determine the top-level
13797 path of a subvolume.
13799 The Guix System produces a bootloader configuration using the operating
13800 system configuration as its sole input; it is therefore necessary to
13801 extract the subvolume name on which @file{/gnu/store} lives (if any)
13802 from that operating system configuration. To better illustrate,
13803 consider a subvolume named 'rootfs' which contains the root file system
13804 data. In such situation, the GRUB bootloader would only see the top
13805 level of the root Btrfs partition, e.g.:
13809 ├── rootfs (subvolume directory)
13810 ├── gnu (normal directory)
13811 ├── store (normal directory)
13815 Thus, the subvolume name must be prepended to the @file{/gnu/store} path
13816 of the kernel, initrd binaries and any other files referred to in the
13817 GRUB configuration that must be found during the early boot.
13819 The next example shows a nested hierarchy of subvolumes and
13824 ├── rootfs (subvolume)
13825 ├── gnu (normal directory)
13826 ├── store (subvolume)
13830 This scenario would work without mounting the 'store' subvolume.
13831 Mounting 'rootfs' is sufficient, since the subvolume name matches its
13832 intended mount point in the file system hierarchy. Alternatively, the
13833 'store' subvolume could be referred to by setting the @code{subvol}
13834 option to either @code{/rootfs/gnu/store} or @code{rootfs/gnu/store}.
13836 Finally, a more contrived example of nested subvolumes:
13840 ├── root-snapshots (subvolume)
13841 ├── root-current (subvolume)
13842 ├── guix-store (subvolume)
13846 Here, the 'guix-store' subvolume doesn't match its intended mount point,
13847 so it is necessary to mount it. The subvolume must be fully specified,
13848 by passing its file name to the @code{subvol} option. To illustrate,
13849 the 'guix-store' subvolume could be mounted on @file{/gnu/store} by using
13850 a file system declaration such as:
13854 (device (file-system-label "btrfs-pool-1"))
13855 (mount-point "/gnu/store")
13857 (options "subvol=root-snapshots/root-current/guix-store,\
13858 compress-force=zstd,space_cache=v2"))
13861 @node Mapped Devices
13862 @section Mapped Devices
13864 @cindex device mapping
13865 @cindex mapped devices
13866 The Linux kernel has a notion of @dfn{device mapping}: a block device,
13867 such as a hard disk partition, can be @dfn{mapped} into another device,
13868 usually in @code{/dev/mapper/},
13869 with additional processing over the data that flows through
13870 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
13871 concept of a ``mapped device'' and that of a file system: both boil down
13872 to @emph{translating} input/output operations made on a file to
13873 operations on its backing store. Thus, the Hurd implements mapped
13874 devices, like file systems, using the generic @dfn{translator} mechanism
13875 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
13876 typical example is encryption device mapping: all writes to the mapped
13877 device are encrypted, and all reads are deciphered, transparently.
13878 Guix extends this notion by considering any device or set of devices that
13879 are @dfn{transformed} in some way to create a new device; for instance,
13880 RAID devices are obtained by @dfn{assembling} several other devices, such
13881 as hard disks or partitions, into a new one that behaves as one partition.
13883 Mapped devices are declared using the @code{mapped-device} form,
13884 defined as follows; for examples, see below.
13886 @deftp {Data Type} mapped-device
13887 Objects of this type represent device mappings that will be made when
13888 the system boots up.
13892 This is either a string specifying the name of the block device to be mapped,
13893 such as @code{"/dev/sda3"}, or a list of such strings when several devices
13894 need to be assembled for creating a new one. In case of LVM this is a
13895 string specifying name of the volume group to be mapped.
13898 This string specifies the name of the resulting mapped device. For
13899 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
13900 specifying @code{"my-partition"} leads to the creation of
13901 the @code{"/dev/mapper/my-partition"} device.
13902 For RAID devices of type @code{raid-device-mapping}, the full device name
13903 such as @code{"/dev/md0"} needs to be given.
13904 LVM logical volumes of type @code{lvm-device-mapping} need to
13905 be specified as @code{"VGNAME-LVNAME"}.
13908 This list of strings specifies names of the resulting mapped devices in case
13909 there are several. The format is identical to @var{target}.
13912 This must be a @code{mapped-device-kind} object, which specifies how
13913 @var{source} is mapped to @var{target}.
13917 @defvr {Scheme Variable} luks-device-mapping
13918 This defines LUKS block device encryption using the @command{cryptsetup}
13919 command from the package with the same name. It relies on the
13920 @code{dm-crypt} Linux kernel module.
13923 @defvr {Scheme Variable} raid-device-mapping
13924 This defines a RAID device, which is assembled using the @code{mdadm}
13925 command from the package with the same name. It requires a Linux kernel
13926 module for the appropriate RAID level to be loaded, such as @code{raid456}
13927 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
13930 @cindex LVM, logical volume manager
13931 @defvr {Scheme Variable} lvm-device-mapping
13932 This defines one or more logical volumes for the Linux
13933 @uref{https://www.sourceware.org/lvm2/, Logical Volume Manager (LVM)}.
13934 The volume group is activated by the @command{vgchange} command from the
13935 @code{lvm2} package.
13938 @cindex disk encryption
13940 The following example specifies a mapping from @file{/dev/sda3} to
13941 @file{/dev/mapper/home} using LUKS---the
13942 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
13943 standard mechanism for disk encryption.
13944 The @file{/dev/mapper/home}
13945 device can then be used as the @code{device} of a @code{file-system}
13946 declaration (@pxref{File Systems}).
13950 (source "/dev/sda3")
13952 (type luks-device-mapping))
13955 Alternatively, to become independent of device numbering, one may obtain
13956 the LUKS UUID (@dfn{unique identifier}) of the source device by a
13960 cryptsetup luksUUID /dev/sda3
13963 and use it as follows:
13967 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
13969 (type luks-device-mapping))
13972 @cindex swap encryption
13973 It is also desirable to encrypt swap space, since swap space may contain
13974 sensitive data. One way to accomplish that is to use a swap file in a
13975 file system on a device mapped via LUKS encryption. In this way, the
13976 swap file is encrypted because the entire device is encrypted.
13977 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
13979 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
13980 may be declared as follows:
13984 (source (list "/dev/sda1" "/dev/sdb1"))
13985 (target "/dev/md0")
13986 (type raid-device-mapping))
13989 The @file{/dev/md0} device can then be used as the @code{device} of a
13990 @code{file-system} declaration (@pxref{File Systems}).
13991 Note that the RAID level need not be given; it is chosen during the
13992 initial creation and formatting of the RAID device and is determined
13993 automatically later.
13995 LVM logical volumes ``alpha'' and ``beta'' from volume group ``vg0'' can
13996 be declared as follows:
14001 (target (list "vg0-alpha" "vg0-beta"))
14002 (type lvm-device-mapping))
14005 Devices @file{/dev/mapper/vg0-alpha} and @file{/dev/mapper/vg0-beta} can
14006 then be used as the @code{device} of a @code{file-system} declaration
14007 (@pxref{File Systems}).
14009 @node User Accounts
14010 @section User Accounts
14014 @cindex user accounts
14015 User accounts and groups are entirely managed through the
14016 @code{operating-system} declaration. They are specified with the
14017 @code{user-account} and @code{user-group} forms:
14023 (supplementary-groups '("wheel" ;allow use of sudo, etc.
14024 "audio" ;sound card
14025 "video" ;video devices such as webcams
14026 "cdrom")) ;the good ol' CD-ROM
14027 (comment "Bob's sister"))
14030 Here's a user account that uses a different shell and a custom home
14031 directory (the default would be @file{"/home/bob"}):
14037 (comment "Alice's bro")
14038 (shell (file-append zsh "/bin/zsh"))
14039 (home-directory "/home/robert"))
14042 When booting or upon completion of @command{guix system reconfigure},
14043 the system ensures that only the user accounts and groups specified in
14044 the @code{operating-system} declaration exist, and with the specified
14045 properties. Thus, account or group creations or modifications made by
14046 directly invoking commands such as @command{useradd} are lost upon
14047 reconfiguration or reboot. This ensures that the system remains exactly
14050 @deftp {Data Type} user-account
14051 Objects of this type represent user accounts. The following members may
14056 The name of the user account.
14060 This is the name (a string) or identifier (a number) of the user group
14061 this account belongs to.
14063 @item @code{supplementary-groups} (default: @code{'()})
14064 Optionally, this can be defined as a list of group names that this
14065 account belongs to.
14067 @item @code{uid} (default: @code{#f})
14068 This is the user ID for this account (a number), or @code{#f}. In the
14069 latter case, a number is automatically chosen by the system when the
14070 account is created.
14072 @item @code{comment} (default: @code{""})
14073 A comment about the account, such as the account owner's full name.
14075 @item @code{home-directory}
14076 This is the name of the home directory for the account.
14078 @item @code{create-home-directory?} (default: @code{#t})
14079 Indicates whether the home directory of this account should be created
14080 if it does not exist yet.
14082 @item @code{shell} (default: Bash)
14083 This is a G-expression denoting the file name of a program to be used as
14084 the shell (@pxref{G-Expressions}). For example, you would refer to the
14085 Bash executable like this:
14088 (file-append bash "/bin/bash")
14092 ... and to the Zsh executable like that:
14095 (file-append zsh "/bin/zsh")
14098 @item @code{system?} (default: @code{#f})
14099 This Boolean value indicates whether the account is a ``system''
14100 account. System accounts are sometimes treated specially; for instance,
14101 graphical login managers do not list them.
14103 @anchor{user-account-password}
14104 @cindex password, for user accounts
14105 @item @code{password} (default: @code{#f})
14106 You would normally leave this field to @code{#f}, initialize user
14107 passwords as @code{root} with the @command{passwd} command, and then let
14108 users change it with @command{passwd}. Passwords set with
14109 @command{passwd} are of course preserved across reboot and
14112 If you @emph{do} want to set an initial password for an account, then
14113 this field must contain the encrypted password, as a string. You can use the
14114 @code{crypt} procedure for this purpose:
14121 ;; Specify a SHA-512-hashed initial password.
14122 (password (crypt "InitialPassword!" "$6$abc")))
14126 The hash of this initial password will be available in a file in
14127 @file{/gnu/store}, readable by all the users, so this method must be used with
14131 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
14132 more information on password encryption, and @ref{Encryption,,, guile, GNU
14133 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
14139 User group declarations are even simpler:
14142 (user-group (name "students"))
14145 @deftp {Data Type} user-group
14146 This type is for, well, user groups. There are just a few fields:
14150 The name of the group.
14152 @item @code{id} (default: @code{#f})
14153 The group identifier (a number). If @code{#f}, a new number is
14154 automatically allocated when the group is created.
14156 @item @code{system?} (default: @code{#f})
14157 This Boolean value indicates whether the group is a ``system'' group.
14158 System groups have low numerical IDs.
14160 @item @code{password} (default: @code{#f})
14161 What, user groups can have a password? Well, apparently yes. Unless
14162 @code{#f}, this field specifies the password of the group.
14167 For convenience, a variable lists all the basic user groups one may
14170 @defvr {Scheme Variable} %base-groups
14171 This is the list of basic user groups that users and/or packages expect
14172 to be present on the system. This includes groups such as ``root'',
14173 ``wheel'', and ``users'', as well as groups used to control access to
14174 specific devices such as ``audio'', ``disk'', and ``cdrom''.
14177 @defvr {Scheme Variable} %base-user-accounts
14178 This is the list of basic system accounts that programs may expect to
14179 find on a GNU/Linux system, such as the ``nobody'' account.
14181 Note that the ``root'' account is not included here. It is a
14182 special-case and is automatically added whether or not it is specified.
14185 @node Keyboard Layout
14186 @section Keyboard Layout
14188 @cindex keyboard layout
14190 To specify what each key of your keyboard does, you need to tell the operating
14191 system what @dfn{keyboard layout} you want to use. The default, when nothing
14192 is specified, is the US English QWERTY layout for 105-key PC keyboards.
14193 However, German speakers will usually prefer the German QWERTZ layout, French
14194 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
14195 or bépo, and they might even want to further customize the effect of some of
14196 the keys. This section explains how to get that done.
14198 @cindex keyboard layout, definition
14199 There are three components that will want to know about your keyboard layout:
14203 The @emph{bootloader} may want to know what keyboard layout you want to use
14204 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
14205 you want, for instance, to make sure that you can type the passphrase of your
14206 encrypted root partition using the right layout.
14209 The @emph{operating system kernel}, Linux, will need that so that the console
14210 is properly configured (@pxref{operating-system Reference,
14211 @code{keyboard-layout}}).
14214 The @emph{graphical display server}, usually Xorg, also has its own idea of
14215 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
14218 Guix allows you to configure all three separately but, fortunately, it allows
14219 you to share the same keyboard layout for all three components.
14221 @cindex XKB, keyboard layouts
14222 Keyboard layouts are represented by records created by the
14223 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
14224 the X Keyboard extension (XKB), each layout has four attributes: a name (often
14225 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
14226 optional variant name, an optional keyboard model name, and a possibly empty
14227 list of additional options. In most cases the layout name is all you care
14230 @deffn {Scheme Procedure} keyboard-layout @var{name} [@var{variant}] @
14231 [#:model] [#:options '()]
14232 Return a new keyboard layout with the given @var{name} and @var{variant}.
14234 @var{name} must be a string such as @code{"fr"}; @var{variant} must be a
14235 string such as @code{"bepo"} or @code{"nodeadkeys"}. See the
14236 @code{xkeyboard-config} package for valid options.
14239 Here are a few examples:
14242 ;; The German QWERTZ layout. Here we assume a standard
14243 ;; "pc105" keyboard model.
14244 (keyboard-layout "de")
14246 ;; The bépo variant of the French layout.
14247 (keyboard-layout "fr" "bepo")
14249 ;; The Catalan layout.
14250 (keyboard-layout "es" "cat")
14252 ;; Arabic layout with "Alt-Shift" to switch to US layout.
14253 (keyboard-layout "ar,us" #:options '("grp:alt_shift_toggle"))
14255 ;; The Latin American Spanish layout. In addition, the
14256 ;; "Caps Lock" key is used as an additional "Ctrl" key,
14257 ;; and the "Menu" key is used as a "Compose" key to enter
14258 ;; accented letters.
14259 (keyboard-layout "latam"
14260 #:options '("ctrl:nocaps" "compose:menu"))
14262 ;; The Russian layout for a ThinkPad keyboard.
14263 (keyboard-layout "ru" #:model "thinkpad")
14265 ;; The "US international" layout, which is the US layout plus
14266 ;; dead keys to enter accented characters. This is for an
14267 ;; Apple MacBook keyboard.
14268 (keyboard-layout "us" "intl" #:model "macbook78")
14271 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
14272 for a complete list of supported layouts, variants, and models.
14274 @cindex keyboard layout, configuration
14275 Let's say you want your system to use the Turkish keyboard layout throughout
14276 your system---bootloader, console, and Xorg. Here's what your system
14277 configuration would look like:
14279 @findex set-xorg-configuration
14281 ;; Using the Turkish layout for the bootloader, the console,
14286 (keyboard-layout (keyboard-layout "tr")) ;for the console
14287 (bootloader (bootloader-configuration
14288 (bootloader grub-efi-bootloader)
14289 (target "/boot/efi")
14290 (keyboard-layout keyboard-layout))) ;for GRUB
14291 (services (cons (set-xorg-configuration
14292 (xorg-configuration ;for Xorg
14293 (keyboard-layout keyboard-layout)))
14294 %desktop-services)))
14297 In the example above, for GRUB and for Xorg, we just refer to the
14298 @code{keyboard-layout} field defined above, but we could just as well refer to
14299 a different layout. The @code{set-xorg-configuration} procedure communicates
14300 the desired Xorg configuration to the graphical log-in manager, by default
14303 We've discussed how to specify the @emph{default} keyboard layout of your
14304 system when it starts, but you can also adjust it at run time:
14308 If you're using GNOME, its settings panel has a ``Region & Language'' entry
14309 where you can select one or more keyboard layouts.
14312 Under Xorg, the @command{setxkbmap} command (from the same-named package)
14313 allows you to change the current layout. For example, this is how you would
14314 change the layout to US Dvorak:
14317 setxkbmap us dvorak
14321 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
14322 console. However, note that @code{loadkeys} does @emph{not} use the XKB
14323 keyboard layout categorization described above. The command below loads the
14324 French bépo layout:
14335 A @dfn{locale} defines cultural conventions for a particular language
14336 and region of the world (@pxref{Locales,,, libc, The GNU C Library
14337 Reference Manual}). Each locale has a name that typically has the form
14338 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
14339 @code{fr_LU.utf8} designates the locale for the French language, with
14340 cultural conventions from Luxembourg, and using the UTF-8 encoding.
14342 @cindex locale definition
14343 Usually, you will want to specify the default locale for the machine
14344 using the @code{locale} field of the @code{operating-system} declaration
14345 (@pxref{operating-system Reference, @code{locale}}).
14347 The selected locale is automatically added to the @dfn{locale
14348 definitions} known to the system if needed, with its codeset inferred
14349 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
14350 @code{UTF-8} codeset. Additional locale definitions can be specified in
14351 the @code{locale-definitions} slot of @code{operating-system}---this is
14352 useful, for instance, if the codeset could not be inferred from the
14353 locale name. The default set of locale definitions includes some widely
14354 used locales, but not all the available locales, in order to save space.
14356 For instance, to add the North Frisian locale for Germany, the value of
14360 (cons (locale-definition
14361 (name "fy_DE.utf8") (source "fy_DE"))
14362 %default-locale-definitions)
14365 Likewise, to save space, one might want @code{locale-definitions} to
14366 list only the locales that are actually used, as in:
14369 (list (locale-definition
14370 (name "ja_JP.eucjp") (source "ja_JP")
14371 (charset "EUC-JP")))
14375 The compiled locale definitions are available at
14376 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
14377 version, which is the default location where the GNU@tie{}libc provided
14378 by Guix looks for locale data. This can be overridden using the
14379 @env{LOCPATH} environment variable (@pxref{locales-and-locpath,
14380 @env{LOCPATH} and locale packages}).
14382 The @code{locale-definition} form is provided by the @code{(gnu system
14383 locale)} module. Details are given below.
14385 @deftp {Data Type} locale-definition
14386 This is the data type of a locale definition.
14391 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
14392 Reference Manual}, for more information on locale names.
14394 @item @code{source}
14395 The name of the source for that locale. This is typically the
14396 @code{@var{language}_@var{territory}} part of the locale name.
14398 @item @code{charset} (default: @code{"UTF-8"})
14399 The ``character set'' or ``code set'' for that locale,
14400 @uref{https://www.iana.org/assignments/character-sets, as defined by
14406 @defvr {Scheme Variable} %default-locale-definitions
14407 A list of commonly used UTF-8 locales, used as the default
14408 value of the @code{locale-definitions} field of @code{operating-system}
14411 @cindex locale name
14412 @cindex normalized codeset in locale names
14413 These locale definitions use the @dfn{normalized codeset} for the part
14414 that follows the dot in the name (@pxref{Using gettextized software,
14415 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
14416 instance it has @code{uk_UA.utf8} but @emph{not}, say,
14417 @code{uk_UA.UTF-8}.
14420 @subsection Locale Data Compatibility Considerations
14422 @cindex incompatibility, of locale data
14423 @code{operating-system} declarations provide a @code{locale-libcs} field
14424 to specify the GNU@tie{}libc packages that are used to compile locale
14425 declarations (@pxref{operating-system Reference}). ``Why would I
14426 care?'', you may ask. Well, it turns out that the binary format of
14427 locale data is occasionally incompatible from one libc version to
14430 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
14431 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
14432 For instance, a program linked against libc version 2.21 is unable to
14433 read locale data produced with libc 2.22; worse, that program
14434 @emph{aborts} instead of simply ignoring the incompatible locale
14435 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
14436 the incompatible locale data, which is already an improvement.}.
14437 Similarly, a program linked against libc 2.22 can read most, but not
14438 all, of the locale data from libc 2.21 (specifically, @env{LC_COLLATE}
14439 data is incompatible); thus calls to @code{setlocale} may fail, but
14440 programs will not abort.
14442 The ``problem'' with Guix is that users have a lot of freedom: They can
14443 choose whether and when to upgrade software in their profiles, and might
14444 be using a libc version different from the one the system administrator
14445 used to build the system-wide locale data.
14447 Fortunately, unprivileged users can also install their own locale data
14448 and define @env{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
14449 @env{GUIX_LOCPATH} and locale packages}).
14451 Still, it is best if the system-wide locale data at
14452 @file{/run/current-system/locale} is built for all the libc versions
14453 actually in use on the system, so that all the programs can access
14454 it---this is especially crucial on a multi-user system. To do that, the
14455 administrator can specify several libc packages in the
14456 @code{locale-libcs} field of @code{operating-system}:
14459 (use-package-modules base)
14463 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
14466 This example would lead to a system containing locale definitions for
14467 both libc 2.21 and the current version of libc in
14468 @file{/run/current-system/locale}.
14474 @cindex system services
14475 An important part of preparing an @code{operating-system} declaration is
14476 listing @dfn{system services} and their configuration (@pxref{Using the
14477 Configuration System}). System services are typically daemons launched
14478 when the system boots, or other actions needed at that time---e.g.,
14479 configuring network access.
14481 Guix has a broad definition of ``service'' (@pxref{Service
14482 Composition}), but many services are managed by the GNU@tie{}Shepherd
14483 (@pxref{Shepherd Services}). On a running system, the @command{herd}
14484 command allows you to list the available services, show their status,
14485 start and stop them, or do other specific operations (@pxref{Jump
14486 Start,,, shepherd, The GNU Shepherd Manual}). For example:
14492 The above command, run as @code{root}, lists the currently defined
14493 services. The @command{herd doc} command shows a synopsis of the given
14494 service and its associated actions:
14498 Run libc's name service cache daemon (nscd).
14500 # herd doc nscd action invalidate
14501 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
14504 The @command{start}, @command{stop}, and @command{restart} sub-commands
14505 have the effect you would expect. For instance, the commands below stop
14506 the nscd service and restart the Xorg display server:
14510 Service nscd has been stopped.
14511 # herd restart xorg-server
14512 Service xorg-server has been stopped.
14513 Service xorg-server has been started.
14516 The following sections document the available services, starting with
14517 the core services, that may be used in an @code{operating-system}
14521 * Base Services:: Essential system services.
14522 * Scheduled Job Execution:: The mcron service.
14523 * Log Rotation:: The rottlog service.
14524 * Networking Services:: Network setup, SSH daemon, etc.
14525 * Unattended Upgrades:: Automated system upgrades.
14526 * X Window:: Graphical display.
14527 * Printing Services:: Local and remote printer support.
14528 * Desktop Services:: D-Bus and desktop services.
14529 * Sound Services:: ALSA and Pulseaudio services.
14530 * Database Services:: SQL databases, key-value stores, etc.
14531 * Mail Services:: IMAP, POP3, SMTP, and all that.
14532 * Messaging Services:: Messaging services.
14533 * Telephony Services:: Telephony services.
14534 * Monitoring Services:: Monitoring services.
14535 * Kerberos Services:: Kerberos services.
14536 * LDAP Services:: LDAP services.
14537 * Web Services:: Web servers.
14538 * Certificate Services:: TLS certificates via Let's Encrypt.
14539 * DNS Services:: DNS daemons.
14540 * VPN Services:: VPN daemons.
14541 * Network File System:: NFS related services.
14542 * Continuous Integration:: The Cuirass service.
14543 * Power Management Services:: Extending battery life.
14544 * Audio Services:: The MPD.
14545 * Virtualization Services:: Virtualization services.
14546 * Version Control Services:: Providing remote access to Git repositories.
14547 * Game Services:: Game servers.
14548 * PAM Mount Service:: Service to mount volumes when logging in.
14549 * Guix Services:: Services relating specifically to Guix.
14550 * Linux Services:: Services tied to the Linux kernel.
14551 * Hurd Services:: Services specific for a Hurd System.
14552 * Miscellaneous Services:: Other services.
14555 @node Base Services
14556 @subsection Base Services
14558 The @code{(gnu services base)} module provides definitions for the basic
14559 services that one expects from the system. The services exported by
14560 this module are listed below.
14562 @defvr {Scheme Variable} %base-services
14563 This variable contains a list of basic services (@pxref{Service Types
14564 and Services}, for more information on service objects) one would
14565 expect from the system: a login service (mingetty) on each tty, syslogd,
14566 the libc name service cache daemon (nscd), the udev device manager, and
14569 This is the default value of the @code{services} field of
14570 @code{operating-system} declarations. Usually, when customizing a
14571 system, you will want to append services to @code{%base-services}, like
14575 (append (list (service avahi-service-type)
14576 (service openssh-service-type))
14581 @defvr {Scheme Variable} special-files-service-type
14582 This is the service that sets up ``special files'' such as
14583 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
14585 The value associated with @code{special-files-service-type} services
14586 must be a list of tuples where the first element is the ``special file''
14587 and the second element is its target. By default it is:
14589 @cindex @file{/bin/sh}
14590 @cindex @file{sh}, in @file{/bin}
14592 `(("/bin/sh" ,(file-append bash "/bin/sh")))
14595 @cindex @file{/usr/bin/env}
14596 @cindex @file{env}, in @file{/usr/bin}
14597 If you want to add, say, @code{/usr/bin/env} to your system, you can
14601 `(("/bin/sh" ,(file-append bash "/bin/sh"))
14602 ("/usr/bin/env" ,(file-append coreutils "/bin/env")))
14605 Since this is part of @code{%base-services}, you can use
14606 @code{modify-services} to customize the set of special files
14607 (@pxref{Service Reference, @code{modify-services}}). But the simple way
14608 to add a special file is @i{via} the @code{extra-special-file} procedure
14612 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
14613 Use @var{target} as the ``special file'' @var{file}.
14615 For example, adding the following lines to the @code{services} field of
14616 your operating system declaration leads to a @file{/usr/bin/env}
14620 (extra-special-file "/usr/bin/env"
14621 (file-append coreutils "/bin/env"))
14625 @deffn {Scheme Procedure} host-name-service @var{name}
14626 Return a service that sets the host name to @var{name}.
14629 @defvr {Scheme Variable} console-font-service-type
14630 Install the given fonts on the specified ttys (fonts are per
14631 virtual console on the kernel Linux). The value of this service is a list of
14632 tty/font pairs. The font can be the name of a font provided by the @code{kbd}
14633 package or any valid argument to @command{setfont}, as in this example:
14636 `(("tty1" . "LatGrkCyr-8x16")
14637 ("tty2" . ,(file-append
14639 "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
14640 ("tty3" . ,(file-append
14642 "/share/consolefonts/ter-132n"))) ; for HDPI
14646 @deffn {Scheme Procedure} login-service @var{config}
14647 Return a service to run login according to @var{config}, a
14648 @code{<login-configuration>} object, which specifies the message of the day,
14649 among other things.
14652 @deftp {Data Type} login-configuration
14653 This is the data type representing the configuration of login.
14658 @cindex message of the day
14659 A file-like object containing the ``message of the day''.
14661 @item @code{allow-empty-passwords?} (default: @code{#t})
14662 Allow empty passwords by default so that first-time users can log in when
14663 the 'root' account has just been created.
14668 @deffn {Scheme Procedure} mingetty-service @var{config}
14669 Return a service to run mingetty according to @var{config}, a
14670 @code{<mingetty-configuration>} object, which specifies the tty to run, among
14674 @deftp {Data Type} mingetty-configuration
14675 This is the data type representing the configuration of Mingetty, which
14676 provides the default implementation of virtual console log-in.
14681 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
14683 @item @code{auto-login} (default: @code{#f})
14684 When true, this field must be a string denoting the user name under
14685 which the system automatically logs in. When it is @code{#f}, a
14686 user name and password must be entered to log in.
14688 @item @code{login-program} (default: @code{#f})
14689 This must be either @code{#f}, in which case the default log-in program
14690 is used (@command{login} from the Shadow tool suite), or a gexp denoting
14691 the name of the log-in program.
14693 @item @code{login-pause?} (default: @code{#f})
14694 When set to @code{#t} in conjunction with @var{auto-login}, the user
14695 will have to press a key before the log-in shell is launched.
14697 @item @code{clear-on-logout?} (default: @code{#t})
14698 When set to @code{#t}, the screen will be cleared after logout.
14700 @item @code{mingetty} (default: @var{mingetty})
14701 The Mingetty package to use.
14706 @deffn {Scheme Procedure} agetty-service @var{config}
14707 Return a service to run agetty according to @var{config}, an
14708 @code{<agetty-configuration>} object, which specifies the tty to run,
14709 among other things.
14712 @deftp {Data Type} agetty-configuration
14713 This is the data type representing the configuration of agetty, which
14714 implements virtual and serial console log-in. See the @code{agetty(8)}
14715 man page for more information.
14720 The name of the console this agetty runs on, as a string---e.g.,
14721 @code{"ttyS0"}. This argument is optional, it will default to
14722 a reasonable default serial port used by the kernel Linux.
14724 For this, if there is a value for an option @code{agetty.tty} in the kernel
14725 command line, agetty will extract the device name of the serial port
14726 from it and use that.
14728 If not and if there is a value for an option @code{console} with a tty in
14729 the Linux command line, agetty will extract the device name of the
14730 serial port from it and use that.
14732 In both cases, agetty will leave the other serial device settings
14733 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
14736 @item @code{baud-rate} (default: @code{#f})
14737 A string containing a comma-separated list of one or more baud rates, in
14740 @item @code{term} (default: @code{#f})
14741 A string containing the value used for the @env{TERM} environment
14744 @item @code{eight-bits?} (default: @code{#f})
14745 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
14748 @item @code{auto-login} (default: @code{#f})
14749 When passed a login name, as a string, the specified user will be logged
14750 in automatically without prompting for their login name or password.
14752 @item @code{no-reset?} (default: @code{#f})
14753 When @code{#t}, don't reset terminal cflags (control modes).
14755 @item @code{host} (default: @code{#f})
14756 This accepts a string containing the ``login_host'', which will be written
14757 into the @file{/var/run/utmpx} file.
14759 @item @code{remote?} (default: @code{#f})
14760 When set to @code{#t} in conjunction with @var{host}, this will add an
14761 @code{-r} fakehost option to the command line of the login program
14762 specified in @var{login-program}.
14764 @item @code{flow-control?} (default: @code{#f})
14765 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
14767 @item @code{no-issue?} (default: @code{#f})
14768 When set to @code{#t}, the contents of the @file{/etc/issue} file will
14769 not be displayed before presenting the login prompt.
14771 @item @code{init-string} (default: @code{#f})
14772 This accepts a string that will be sent to the tty or modem before
14773 sending anything else. It can be used to initialize a modem.
14775 @item @code{no-clear?} (default: @code{#f})
14776 When set to @code{#t}, agetty will not clear the screen before showing
14779 @item @code{login-program} (default: (file-append shadow "/bin/login"))
14780 This must be either a gexp denoting the name of a log-in program, or
14781 unset, in which case the default value is the @command{login} from the
14784 @item @code{local-line} (default: @code{#f})
14785 Control the CLOCAL line flag. This accepts one of three symbols as
14786 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
14787 the default value chosen by agetty is @code{'auto}.
14789 @item @code{extract-baud?} (default: @code{#f})
14790 When set to @code{#t}, instruct agetty to try to extract the baud rate
14791 from the status messages produced by certain types of modems.
14793 @item @code{skip-login?} (default: @code{#f})
14794 When set to @code{#t}, do not prompt the user for a login name. This
14795 can be used with @var{login-program} field to use non-standard login
14798 @item @code{no-newline?} (default: @code{#f})
14799 When set to @code{#t}, do not print a newline before printing the
14800 @file{/etc/issue} file.
14802 @c Is this dangerous only when used with login-program, or always?
14803 @item @code{login-options} (default: @code{#f})
14804 This option accepts a string containing options that are passed to the
14805 login program. When used with the @var{login-program}, be aware that a
14806 malicious user could try to enter a login name containing embedded
14807 options that could be parsed by the login program.
14809 @item @code{login-pause} (default: @code{#f})
14810 When set to @code{#t}, wait for any key before showing the login prompt.
14811 This can be used in conjunction with @var{auto-login} to save memory by
14812 lazily spawning shells.
14814 @item @code{chroot} (default: @code{#f})
14815 Change root to the specified directory. This option accepts a directory
14818 @item @code{hangup?} (default: @code{#f})
14819 Use the Linux system call @code{vhangup} to do a virtual hangup of the
14820 specified terminal.
14822 @item @code{keep-baud?} (default: @code{#f})
14823 When set to @code{#t}, try to keep the existing baud rate. The baud
14824 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
14827 @item @code{timeout} (default: @code{#f})
14828 When set to an integer value, terminate if no user name could be read
14829 within @var{timeout} seconds.
14831 @item @code{detect-case?} (default: @code{#f})
14832 When set to @code{#t}, turn on support for detecting an uppercase-only
14833 terminal. This setting will detect a login name containing only
14834 uppercase letters as indicating an uppercase-only terminal and turn on
14835 some upper-to-lower case conversions. Note that this will not support
14836 Unicode characters.
14838 @item @code{wait-cr?} (default: @code{#f})
14839 When set to @code{#t}, wait for the user or modem to send a
14840 carriage-return or linefeed character before displaying
14841 @file{/etc/issue} or login prompt. This is typically used with the
14842 @var{init-string} option.
14844 @item @code{no-hints?} (default: @code{#f})
14845 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
14848 @item @code{no-hostname?} (default: @code{#f})
14849 By default, the hostname is printed. When this option is set to
14850 @code{#t}, no hostname will be shown at all.
14852 @item @code{long-hostname?} (default: @code{#f})
14853 By default, the hostname is only printed until the first dot. When this
14854 option is set to @code{#t}, the fully qualified hostname by
14855 @code{gethostname} or @code{getaddrinfo} is shown.
14857 @item @code{erase-characters} (default: @code{#f})
14858 This option accepts a string of additional characters that should be
14859 interpreted as backspace when the user types their login name.
14861 @item @code{kill-characters} (default: @code{#f})
14862 This option accepts a string that should be interpreted to mean ``ignore
14863 all previous characters'' (also called a ``kill'' character) when the user
14864 types their login name.
14866 @item @code{chdir} (default: @code{#f})
14867 This option accepts, as a string, a directory path that will be changed
14870 @item @code{delay} (default: @code{#f})
14871 This options accepts, as an integer, the number of seconds to sleep
14872 before opening the tty and displaying the login prompt.
14874 @item @code{nice} (default: @code{#f})
14875 This option accepts, as an integer, the nice value with which to run the
14876 @command{login} program.
14878 @item @code{extra-options} (default: @code{'()})
14879 This option provides an ``escape hatch'' for the user to provide arbitrary
14880 command-line arguments to @command{agetty} as a list of strings.
14885 @deffn {Scheme Procedure} kmscon-service-type @var{config}
14886 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
14887 according to @var{config}, a @code{<kmscon-configuration>} object, which
14888 specifies the tty to run, among other things.
14891 @deftp {Data Type} kmscon-configuration
14892 This is the data type representing the configuration of Kmscon, which
14893 implements virtual console log-in.
14897 @item @code{virtual-terminal}
14898 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
14900 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
14901 A gexp denoting the name of the log-in program. The default log-in program is
14902 @command{login} from the Shadow tool suite.
14904 @item @code{login-arguments} (default: @code{'("-p")})
14905 A list of arguments to pass to @command{login}.
14907 @item @code{auto-login} (default: @code{#f})
14908 When passed a login name, as a string, the specified user will be logged
14909 in automatically without prompting for their login name or password.
14911 @item @code{hardware-acceleration?} (default: #f)
14912 Whether to use hardware acceleration.
14914 @item @code{kmscon} (default: @var{kmscon})
14915 The Kmscon package to use.
14920 @cindex name service cache daemon
14922 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
14923 [#:name-services '()]
14924 Return a service that runs the libc name service cache daemon (nscd) with the
14925 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
14926 Service Switch}, for an example.
14928 For convenience, the Shepherd service for nscd provides the following actions:
14932 @cindex cache invalidation, nscd
14933 @cindex nscd, cache invalidation
14934 This invalidate the given cache. For instance, running:
14937 herd invalidate nscd hosts
14941 invalidates the host name lookup cache of nscd.
14944 Running @command{herd statistics nscd} displays information about nscd usage
14950 @defvr {Scheme Variable} %nscd-default-configuration
14951 This is the default @code{<nscd-configuration>} value (see below) used
14952 by @code{nscd-service}. It uses the caches defined by
14953 @code{%nscd-default-caches}; see below.
14956 @deftp {Data Type} nscd-configuration
14957 This is the data type representing the name service cache daemon (nscd)
14962 @item @code{name-services} (default: @code{'()})
14963 List of packages denoting @dfn{name services} that must be visible to
14964 the nscd---e.g., @code{(list @var{nss-mdns})}.
14966 @item @code{glibc} (default: @var{glibc})
14967 Package object denoting the GNU C Library providing the @command{nscd}
14970 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
14971 Name of the nscd log file. This is where debugging output goes when
14972 @code{debug-level} is strictly positive.
14974 @item @code{debug-level} (default: @code{0})
14975 Integer denoting the debugging levels. Higher numbers mean that more
14976 debugging output is logged.
14978 @item @code{caches} (default: @code{%nscd-default-caches})
14979 List of @code{<nscd-cache>} objects denoting things to be cached; see
14985 @deftp {Data Type} nscd-cache
14986 Data type representing a cache database of nscd and its parameters.
14990 @item @code{database}
14991 This is a symbol representing the name of the database to be cached.
14992 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
14993 @code{services}, which designate the corresponding NSS database
14994 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
14996 @item @code{positive-time-to-live}
14997 @itemx @code{negative-time-to-live} (default: @code{20})
14998 A number representing the number of seconds during which a positive or
14999 negative lookup result remains in cache.
15001 @item @code{check-files?} (default: @code{#t})
15002 Whether to check for updates of the files corresponding to
15005 For instance, when @var{database} is @code{hosts}, setting this flag
15006 instructs nscd to check for updates in @file{/etc/hosts} and to take
15009 @item @code{persistent?} (default: @code{#t})
15010 Whether the cache should be stored persistently on disk.
15012 @item @code{shared?} (default: @code{#t})
15013 Whether the cache should be shared among users.
15015 @item @code{max-database-size} (default: 32@tie{}MiB)
15016 Maximum size in bytes of the database cache.
15018 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
15019 @c settings, so leave them out.
15024 @defvr {Scheme Variable} %nscd-default-caches
15025 List of @code{<nscd-cache>} objects used by default by
15026 @code{nscd-configuration} (see above).
15028 It enables persistent and aggressive caching of service and host name
15029 lookups. The latter provides better host name lookup performance,
15030 resilience in the face of unreliable name servers, and also better
15031 privacy---often the result of host name lookups is in local cache, so
15032 external name servers do not even need to be queried.
15035 @anchor{syslog-configuration-type}
15038 @deftp {Data Type} syslog-configuration
15039 This data type represents the configuration of the syslog daemon.
15042 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
15043 The syslog daemon to use.
15045 @item @code{config-file} (default: @code{%default-syslog.conf})
15046 The syslog configuration file to use.
15051 @anchor{syslog-service}
15053 @deffn {Scheme Procedure} syslog-service @var{config}
15054 Return a service that runs a syslog daemon according to @var{config}.
15056 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
15057 information on the configuration file syntax.
15060 @defvr {Scheme Variable} guix-service-type
15061 This is the type of the service that runs the build daemon,
15062 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
15063 @code{guix-configuration} record as described below.
15066 @anchor{guix-configuration-type}
15067 @deftp {Data Type} guix-configuration
15068 This data type represents the configuration of the Guix build daemon.
15069 @xref{Invoking guix-daemon}, for more information.
15072 @item @code{guix} (default: @var{guix})
15073 The Guix package to use.
15075 @item @code{build-group} (default: @code{"guixbuild"})
15076 Name of the group for build user accounts.
15078 @item @code{build-accounts} (default: @code{10})
15079 Number of build user accounts to create.
15081 @item @code{authorize-key?} (default: @code{#t})
15082 @cindex substitutes, authorization thereof
15083 Whether to authorize the substitute keys listed in
15084 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
15085 (@pxref{Substitutes}).
15087 When @code{authorize-key?} is true, @file{/etc/guix/acl} cannot be
15088 changed by invoking @command{guix archive --authorize}. You must
15089 instead adjust @code{guix-configuration} as you wish and reconfigure the
15090 system. This ensures that your operating system configuration file is
15094 When booting or reconfiguring to a system where @code{authorize-key?}
15095 is true, the existing @file{/etc/guix/acl} file is backed up as
15096 @file{/etc/guix/acl.bak} if it was determined to be a manually modified
15097 file. This is to facilitate migration from earlier versions, which
15098 allowed for in-place modifications to @file{/etc/guix/acl}.
15101 @vindex %default-authorized-guix-keys
15102 @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
15103 The list of authorized key files for archive imports, as a list of
15104 string-valued gexps (@pxref{Invoking guix archive}). By default, it
15105 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
15106 See @code{substitute-urls} below for an example on how to change it.
15108 @item @code{use-substitutes?} (default: @code{#t})
15109 Whether to use substitutes.
15111 @item @code{substitute-urls} (default: @code{%default-substitute-urls})
15112 The list of URLs where to look for substitutes by default.
15114 Suppose you would like to fetch substitutes from @code{guix.example.org}
15115 in addition to @code{@value{SUBSTITUTE-SERVER}}. You will need to do
15116 two things: (1) add @code{guix.example.org} to @code{substitute-urls},
15117 and (2) authorize its signing key, having done appropriate checks
15118 (@pxref{Substitute Server Authorization}). The configuration below does
15122 (guix-configuration
15124 (append (list "https://guix.example.org")
15125 %default-substitute-urls))
15127 (append (list (local-file "./guix.example.org-key.pub"))
15128 %default-authorized-guix-keys)))
15131 This example assumes that the file @file{./guix.example.org-key.pub}
15132 contains the public key that @code{guix.example.org} uses to sign
15135 @item @code{max-silent-time} (default: @code{0})
15136 @itemx @code{timeout} (default: @code{0})
15137 The number of seconds of silence and the number of seconds of activity,
15138 respectively, after which a build process times out. A value of zero
15139 disables the timeout.
15141 @item @code{log-compression} (default: @code{'bzip2})
15142 The type of compression used for build logs---one of @code{gzip},
15143 @code{bzip2}, or @code{none}.
15145 @item @code{discover?} (default: @code{#f})
15146 Whether to discover substitute servers on the local network using mDNS
15149 @item @code{extra-options} (default: @code{'()})
15150 List of extra command-line options for @command{guix-daemon}.
15152 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
15153 File where @command{guix-daemon}'s standard output and standard error
15156 @cindex HTTP proxy, for @code{guix-daemon}
15157 @cindex proxy, for @code{guix-daemon} HTTP access
15158 @item @code{http-proxy} (default: @code{#f})
15159 The URL of the HTTP and HTTPS proxy used for downloading fixed-output
15160 derivations and substitutes.
15162 It is also possible to change the daemon's proxy at run time through the
15163 @code{set-http-proxy} action, which restarts it:
15166 herd set-http-proxy guix-daemon http://localhost:8118
15169 To clear the proxy settings, run:
15172 herd set-http-proxy guix-daemon
15175 @item @code{tmpdir} (default: @code{#f})
15176 A directory path where the @command{guix-daemon} will perform builds.
15181 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
15182 Run @var{udev}, which populates the @file{/dev} directory dynamically.
15183 udev rules can be provided as a list of files through the @var{rules}
15184 variable. The procedures @code{udev-rule}, @code{udev-rules-service}
15185 and @code{file->udev-rule} from @code{(gnu services base)} simplify the
15186 creation of such rule files.
15188 The @command{herd rules udev} command, as root, returns the name of the
15189 directory containing all the active udev rules.
15192 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
15193 Return a udev-rule file named @var{file-name} containing the rules
15194 defined by the @var{contents} literal.
15196 In the following example, a rule for a USB device is defined to be
15197 stored in the file @file{90-usb-thing.rules}. The rule runs a script
15198 upon detecting a USB device with a given product identifier.
15201 (define %example-udev-rule
15203 "90-usb-thing.rules"
15204 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
15205 "ATTR@{product@}==\"Example\", "
15206 "RUN+=\"/path/to/script\"")))
15210 @deffn {Scheme Procedure} udev-rules-service [@var{name} @var{rules}] @
15211 [#:groups @var{groups}]
15212 Return a service that extends @code{udev-service-type } with @var{rules}
15213 and @code{account-service-type} with @var{groups} as system groups.
15214 This works by creating a singleton service type
15215 @code{@var{name}-udev-rules}, of which the returned service is an
15218 Here we show how it can be used to extend @code{udev-service-type} with the
15219 previously defined rule @code{%example-udev-rule}.
15225 (cons (udev-rules-service 'usb-thing %example-udev-rule)
15226 %desktop-services)))
15230 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
15231 Return a udev file named @var{file-name} containing the rules defined
15232 within @var{file}, a file-like object.
15234 The following example showcases how we can use an existing rule file.
15237 (use-modules (guix download) ;for url-fetch
15238 (guix packages) ;for origin
15241 (define %android-udev-rules
15243 "51-android-udev.rules"
15244 (let ((version "20170910"))
15247 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
15248 "android-udev-rules/" version "/51-android.rules"))
15250 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
15254 Additionally, Guix package definitions can be included in @var{rules} in
15255 order to extend the udev rules with the definitions found under their
15256 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
15257 @var{file->udev-rule} example, we could have used the
15258 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
15259 packages android)} module.
15261 The following example shows how to use the @var{android-udev-rules}
15262 package so that the Android tool @command{adb} can detect devices
15263 without root privileges. It also details how to create the
15264 @code{adbusers} group, which is required for the proper functioning of
15265 the rules defined within the @code{android-udev-rules} package. To
15266 create such a group, we must define it both as part of the
15267 @code{supplementary-groups} of our @code{user-account} declaration, as
15268 well as in the @var{groups} of the @code{udev-rules-service} procedure.
15271 (use-modules (gnu packages android) ;for android-udev-rules
15272 (gnu system shadow) ;for user-group
15277 (users (cons (user-account
15279 (supplementary-groups
15280 '("adbusers" ;for adb
15281 "wheel" "netdev" "audio" "video")))))
15284 (cons (udev-rules-service 'android android-udev-rules
15285 #:groups '("adbusers"))
15286 %desktop-services)))
15289 @defvr {Scheme Variable} urandom-seed-service-type
15290 Save some entropy in @code{%random-seed-file} to seed @file{/dev/urandom}
15291 when rebooting. It also tries to seed @file{/dev/urandom} from
15292 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
15296 @defvr {Scheme Variable} %random-seed-file
15297 This is the name of the file where some random bytes are saved by
15298 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
15299 It defaults to @file{/var/lib/random-seed}.
15304 @defvr {Scheme Variable} gpm-service-type
15305 This is the type of the service that runs GPM, the @dfn{general-purpose
15306 mouse daemon}, which provides mouse support to the Linux console. GPM
15307 allows users to use the mouse in the console, notably to select, copy,
15310 The value for services of this type must be a @code{gpm-configuration}
15311 (see below). This service is not part of @code{%base-services}.
15314 @deftp {Data Type} gpm-configuration
15315 Data type representing the configuration of GPM.
15318 @item @code{options} (default: @code{%default-gpm-options})
15319 Command-line options passed to @command{gpm}. The default set of
15320 options instruct @command{gpm} to listen to mouse events on
15321 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
15324 @item @code{gpm} (default: @code{gpm})
15325 The GPM package to use.
15330 @anchor{guix-publish-service-type}
15331 @deffn {Scheme Variable} guix-publish-service-type
15332 This is the service type for @command{guix publish} (@pxref{Invoking
15333 guix publish}). Its value must be a @code{guix-publish-configuration}
15334 object, as described below.
15336 This assumes that @file{/etc/guix} already contains a signing key pair as
15337 created by @command{guix archive --generate-key} (@pxref{Invoking guix
15338 archive}). If that is not the case, the service will fail to start.
15341 @deftp {Data Type} guix-publish-configuration
15342 Data type representing the configuration of the @code{guix publish}
15346 @item @code{guix} (default: @code{guix})
15347 The Guix package to use.
15349 @item @code{port} (default: @code{80})
15350 The TCP port to listen for connections.
15352 @item @code{host} (default: @code{"localhost"})
15353 The host (and thus, network interface) to listen to. Use
15354 @code{"0.0.0.0"} to listen on all the network interfaces.
15356 @item @code{compression} (default: @code{'(("gzip" 3))})
15357 This is a list of compression method/level tuple used when compressing
15358 substitutes. For example, to compress all substitutes with @emph{both} lzip
15359 at level 7 and gzip at level 9, write:
15362 '(("lzip" 7) ("gzip" 9))
15365 Level 9 achieves the best compression ratio at the expense of increased CPU
15366 usage, whereas level 1 achieves fast compression.
15368 An empty list disables compression altogether.
15370 @item @code{nar-path} (default: @code{"nar"})
15371 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
15372 publish, @option{--nar-path}}, for details.
15374 @item @code{cache} (default: @code{#f})
15375 When it is @code{#f}, disable caching and instead generate archives on
15376 demand. Otherwise, this should be the name of a directory---e.g.,
15377 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
15378 archives and meta-data ready to be sent. @xref{Invoking guix publish,
15379 @option{--cache}}, for more information on the tradeoffs involved.
15381 @item @code{workers} (default: @code{#f})
15382 When it is an integer, this is the number of worker threads used for
15383 caching; when @code{#f}, the number of processors is used.
15384 @xref{Invoking guix publish, @option{--workers}}, for more information.
15386 @item @code{cache-bypass-threshold} (default: 10 MiB)
15387 When @code{cache} is true, this is the maximum size in bytes of a store
15388 item for which @command{guix publish} may bypass its cache in case of a
15389 cache miss. @xref{Invoking guix publish,
15390 @option{--cache-bypass-threshold}}, for more information.
15392 @item @code{ttl} (default: @code{#f})
15393 When it is an integer, this denotes the @dfn{time-to-live} in seconds
15394 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
15395 for more information.
15399 @anchor{rngd-service}
15400 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
15401 [#:device "/dev/hwrng"]
15402 Return a service that runs the @command{rngd} program from @var{rng-tools}
15403 to add @var{device} to the kernel's entropy pool. The service will fail if
15404 @var{device} does not exist.
15407 @anchor{pam-limits-service}
15408 @cindex session limits
15413 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
15415 Return a service that installs a configuration file for the
15416 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
15417 @code{pam_limits} module}. The procedure optionally takes a list of
15418 @code{pam-limits-entry} values, which can be used to specify
15419 @code{ulimit} limits and nice priority limits to user sessions.
15421 The following limits definition sets two hard and soft limits for all
15422 login sessions of users in the @code{realtime} group:
15425 (pam-limits-service
15427 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
15428 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
15431 The first entry increases the maximum realtime priority for
15432 non-privileged processes; the second entry lifts any restriction of the
15433 maximum address space that can be locked in memory. These settings are
15434 commonly used for real-time audio systems.
15437 @node Scheduled Job Execution
15438 @subsection Scheduled Job Execution
15442 @cindex scheduling jobs
15443 The @code{(gnu services mcron)} module provides an interface to
15444 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
15445 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
15446 Unix @command{cron} daemon; the main difference is that it is
15447 implemented in Guile Scheme, which provides a lot of flexibility when
15448 specifying the scheduling of jobs and their actions.
15450 The example below defines an operating system that runs the
15451 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
15452 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
15453 well as the @command{mkid} command on behalf of an unprivileged user
15454 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
15455 gexps to introduce job definitions that are passed to mcron
15456 (@pxref{G-Expressions}).
15459 (use-modules (guix) (gnu) (gnu services mcron))
15460 (use-package-modules base idutils)
15462 (define updatedb-job
15463 ;; Run 'updatedb' at 3AM every day. Here we write the
15464 ;; job's action as a Scheme procedure.
15465 #~(job '(next-hour '(3))
15467 (execl (string-append #$findutils "/bin/updatedb")
15469 "--prunepaths=/tmp /var/tmp /gnu/store"))))
15471 (define garbage-collector-job
15472 ;; Collect garbage 5 minutes after midnight every day.
15473 ;; The job's action is a shell command.
15474 #~(job "5 0 * * *" ;Vixie cron syntax
15477 (define idutils-job
15478 ;; Update the index database as user "charlie" at 12:15PM
15479 ;; and 19:15PM. This runs from the user's home directory.
15480 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
15481 (string-append #$idutils "/bin/mkid src")
15487 ;; %BASE-SERVICES already includes an instance of
15488 ;; 'mcron-service-type', which we extend with additional
15489 ;; jobs using 'simple-service'.
15490 (services (cons (simple-service 'my-cron-jobs
15492 (list garbage-collector-job
15498 For more complex jobs defined in Scheme where you need control over the top
15499 level, for instance to introduce a @code{use-modules} form, you can move your
15500 code to a separate program using the @code{program-file} procedure of the
15501 @code{(guix gexp)} module (@pxref{G-Expressions}). The example below
15505 (define %battery-alert-job
15506 ;; Beep when the battery percentage falls below %MIN-LEVEL.
15508 '(next-minute (range 0 60 1))
15510 "battery-alert.scm"
15511 (with-imported-modules (source-module-closure
15512 '((guix build utils)))
15514 (use-modules (guix build utils)
15517 (ice-9 textual-ports)
15520 (define %min-level 20)
15522 (setenv "LC_ALL" "C") ;ensure English output
15523 (and-let* ((input-pipe (open-pipe*
15525 #$(file-append acpi "/bin/acpi")))
15526 (output (get-string-all input-pipe))
15527 (m (string-match "Discharging, ([0-9]+)%" output))
15528 (level (string->number (match:substring m 1)))
15529 ((< level %min-level)))
15530 (format #t "warning: Battery level is low (~a%)~%" level)
15531 (invoke #$(file-append beep "/bin/beep") "-r5")))))))
15534 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
15535 for more information on mcron job specifications. Below is the
15536 reference of the mcron service.
15538 On a running system, you can use the @code{schedule} action of the service to
15539 visualize the mcron jobs that will be executed next:
15542 # herd schedule mcron
15546 The example above lists the next five tasks that will be executed, but you can
15547 also specify the number of tasks to display:
15550 # herd schedule mcron 10
15553 @defvr {Scheme Variable} mcron-service-type
15554 This is the type of the @code{mcron} service, whose value is an
15555 @code{mcron-configuration} object.
15557 This service type can be the target of a service extension that provides
15558 it additional job specifications (@pxref{Service Composition}). In
15559 other words, it is possible to define services that provide additional
15563 @deftp {Data Type} mcron-configuration
15564 Data type representing the configuration of mcron.
15567 @item @code{mcron} (default: @var{mcron})
15568 The mcron package to use.
15571 This is a list of gexps (@pxref{G-Expressions}), where each gexp
15572 corresponds to an mcron job specification (@pxref{Syntax, mcron job
15573 specifications,, mcron, GNU@tie{}mcron}).
15579 @subsection Log Rotation
15582 @cindex log rotation
15584 Log files such as those found in @file{/var/log} tend to grow endlessly,
15585 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
15586 their contents in separate files, possibly compressed. The @code{(gnu
15587 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
15588 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
15590 This service is part of @code{%base-services}, and thus enabled by
15591 default, with the default settings, for commonly encountered log files.
15592 The example below shows how to extend it with an additional
15593 @dfn{rotation}, should you need to do that (usually, services that
15594 produce log files already take care of that):
15597 (use-modules (guix) (gnu))
15598 (use-service-modules admin)
15600 (define my-log-files
15601 ;; Log files that I want to rotate.
15602 '("/var/log/something.log" "/var/log/another.log"))
15606 (services (cons (simple-service 'rotate-my-stuff
15607 rottlog-service-type
15608 (list (log-rotation
15610 (files my-log-files))))
15614 @defvr {Scheme Variable} rottlog-service-type
15615 This is the type of the Rottlog service, whose value is a
15616 @code{rottlog-configuration} object.
15618 Other services can extend this one with new @code{log-rotation} objects
15619 (see below), thereby augmenting the set of files to be rotated.
15621 This service type can define mcron jobs (@pxref{Scheduled Job
15622 Execution}) to run the rottlog service.
15625 @deftp {Data Type} rottlog-configuration
15626 Data type representing the configuration of rottlog.
15629 @item @code{rottlog} (default: @code{rottlog})
15630 The Rottlog package to use.
15632 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
15633 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
15634 rottlog, GNU Rot[t]log Manual}).
15636 @item @code{rotations} (default: @code{%default-rotations})
15637 A list of @code{log-rotation} objects as defined below.
15640 This is a list of gexps where each gexp corresponds to an mcron job
15641 specification (@pxref{Scheduled Job Execution}).
15645 @deftp {Data Type} log-rotation
15646 Data type representing the rotation of a group of log files.
15648 Taking an example from the Rottlog manual (@pxref{Period Related File
15649 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
15655 (files '("/var/log/apache/*"))
15656 (options '("storedir apache-archives"
15662 The list of fields is as follows:
15665 @item @code{frequency} (default: @code{'weekly})
15666 The log rotation frequency, a symbol.
15669 The list of files or file glob patterns to rotate.
15671 @item @code{options} (default: @code{'()})
15672 The list of rottlog options for this rotation (@pxref{Configuration
15673 parameters,,, rottlog, GNU Rot[t]lg Manual}).
15675 @item @code{post-rotate} (default: @code{#f})
15676 Either @code{#f} or a gexp to execute once the rotation has completed.
15680 @defvr {Scheme Variable} %default-rotations
15681 Specifies weekly rotation of @code{%rotated-files} and of
15682 @file{/var/log/guix-daemon.log}.
15685 @defvr {Scheme Variable} %rotated-files
15686 The list of syslog-controlled files to be rotated. By default it is:
15687 @code{'("/var/log/messages" "/var/log/secure" "/var/log/debug" \
15688 "/var/log/maillog")}.
15691 @node Networking Services
15692 @subsection Networking Services
15694 The @code{(gnu services networking)} module provides services to configure
15695 the network interface.
15697 @cindex DHCP, networking service
15698 @defvr {Scheme Variable} dhcp-client-service-type
15699 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
15700 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
15701 is the DHCP client package to use, @code{isc-dhcp} by default.
15704 @deffn {Scheme Procedure} dhcpd-service-type
15705 This type defines a service that runs a DHCP daemon. To create a
15706 service of this type, you must supply a @code{<dhcpd-configuration>}.
15710 (service dhcpd-service-type
15711 (dhcpd-configuration
15712 (config-file (local-file "my-dhcpd.conf"))
15713 (interfaces '("enp0s25"))))
15717 @deftp {Data Type} dhcpd-configuration
15719 @item @code{package} (default: @code{isc-dhcp})
15720 The package that provides the DHCP daemon. This package is expected to
15721 provide the daemon at @file{sbin/dhcpd} relative to its output
15722 directory. The default package is the
15723 @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
15724 @item @code{config-file} (default: @code{#f})
15725 The configuration file to use. This is required. It will be passed to
15726 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
15727 object (@pxref{G-Expressions, file-like objects}). See @code{man
15728 dhcpd.conf} for details on the configuration file syntax.
15729 @item @code{version} (default: @code{"4"})
15730 The DHCP version to use. The ISC DHCP server supports the values ``4'',
15731 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
15732 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
15734 @item @code{run-directory} (default: @code{"/run/dhcpd"})
15735 The run directory to use. At service activation time, this directory
15736 will be created if it does not exist.
15737 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
15738 The PID file to use. This corresponds to the @code{-pf} option of
15739 @code{dhcpd}. See @code{man dhcpd} for details.
15740 @item @code{interfaces} (default: @code{'()})
15741 The names of the network interfaces on which dhcpd should listen for
15742 broadcasts. If this list is not empty, then its elements (which must be
15743 strings) will be appended to the @code{dhcpd} invocation when starting
15744 the daemon. It may not be necessary to explicitly specify any
15745 interfaces here; see @code{man dhcpd} for details.
15749 @defvr {Scheme Variable} static-networking-service-type
15750 This is the type for statically-configured network interfaces.
15751 @c TODO Document <static-networking> data structures.
15754 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
15755 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
15756 [#:requirement @code{'(udev)}]
15757 Return a service that starts @var{interface} with address @var{ip}. If
15758 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
15759 it must be a string specifying the default network gateway. @var{requirement}
15760 can be used to declare a dependency on another service before configuring the
15763 This procedure can be called several times, one for each network
15764 interface of interest. Behind the scenes what it does is extend
15765 @code{static-networking-service-type} with additional network interfaces
15771 (static-networking-service "eno1" "192.168.1.82"
15772 #:gateway "192.168.1.2"
15773 #:name-servers '("192.168.1.2"))
15780 @cindex network management
15781 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
15782 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
15783 management daemon that aims to simplify wired and wireless networking.
15785 This service adds the @var{wicd} package to the global profile, providing
15786 several commands to interact with the daemon and configure networking:
15787 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
15788 and @command{wicd-curses} user interfaces.
15791 @cindex ModemManager
15793 @defvr {Scheme Variable} modem-manager-service-type
15794 This is the service type for the
15795 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
15796 service. The value for this service type is a
15797 @code{modem-manager-configuration} record.
15799 This service is part of @code{%desktop-services} (@pxref{Desktop
15803 @deftp {Data Type} modem-manager-configuration
15804 Data type representing the configuration of ModemManager.
15807 @item @code{modem-manager} (default: @code{modem-manager})
15808 The ModemManager package to use.
15813 @cindex USB_ModeSwitch
15814 @cindex Modeswitching
15816 @defvr {Scheme Variable} usb-modeswitch-service-type
15817 This is the service type for the
15818 @uref{https://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch} service. The
15819 value for this service type is a @code{usb-modeswitch-configuration} record.
15821 When plugged in, some USB modems (and other USB devices) initially present
15822 themselves as a read-only storage medium and not as a modem. They need to be
15823 @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
15824 installs udev rules to automatically modeswitch these devices when they are
15827 This service is part of @code{%desktop-services} (@pxref{Desktop
15831 @deftp {Data Type} usb-modeswitch-configuration
15832 Data type representing the configuration of USB_ModeSwitch.
15835 @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
15836 The USB_ModeSwitch package providing the binaries for modeswitching.
15838 @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
15839 The package providing the device data and udev rules file used by
15842 @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
15843 Which config file to use for the USB_ModeSwitch dispatcher. By default the
15844 config file shipped with USB_ModeSwitch is used which disables logging to
15845 @file{/var/log} among other default settings. If set to @code{#f}, no config
15851 @cindex NetworkManager
15853 @defvr {Scheme Variable} network-manager-service-type
15854 This is the service type for the
15855 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
15856 service. The value for this service type is a
15857 @code{network-manager-configuration} record.
15859 This service is part of @code{%desktop-services} (@pxref{Desktop
15863 @deftp {Data Type} network-manager-configuration
15864 Data type representing the configuration of NetworkManager.
15867 @item @code{network-manager} (default: @code{network-manager})
15868 The NetworkManager package to use.
15870 @item @code{dns} (default: @code{"default"})
15871 Processing mode for DNS, which affects how NetworkManager uses the
15872 @code{resolv.conf} configuration file.
15876 NetworkManager will update @code{resolv.conf} to reflect the nameservers
15877 provided by currently active connections.
15880 NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
15881 @dfn{conditional forwarding} configuration if you are connected to a VPN, and
15882 then update @code{resolv.conf} to point to the local nameserver.
15884 With this setting, you can share your network connection. For example when
15885 you want to share your network connection to another laptop @i{via} an
15886 Ethernet cable, you can open @command{nm-connection-editor} and configure the
15887 Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
15888 and reestablish the connection (or reboot).
15890 You can also set up a @dfn{host-to-guest connection} to QEMU VMs
15891 (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
15892 e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
15893 browser on your host system, or connect to the VM @i{via} SSH
15894 (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
15895 host-to-guest connection, run this command once:
15898 nmcli connection add type tun \
15899 connection.interface-name tap0 \
15900 tun.mode tap tun.owner $(id -u) \
15901 ipv4.method shared \
15902 ipv4.addresses 172.28.112.1/24
15905 Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
15906 @option{-nic tap,ifname=tap0,script=no,downscript=no} to
15907 @command{qemu-system-...}.
15910 NetworkManager will not modify @code{resolv.conf}.
15913 @item @code{vpn-plugins} (default: @code{'()})
15914 This is the list of available plugins for virtual private networks
15915 (VPNs). An example of this is the @code{network-manager-openvpn}
15916 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
15922 @deffn {Scheme Variable} connman-service-type
15923 This is the service type to run @url{https://01.org/connman,Connman},
15924 a network connection manager.
15926 Its value must be an
15927 @code{connman-configuration} record as in this example:
15930 (service connman-service-type
15931 (connman-configuration
15932 (disable-vpn? #t)))
15935 See below for details about @code{connman-configuration}.
15938 @deftp {Data Type} connman-configuration
15939 Data Type representing the configuration of connman.
15942 @item @code{connman} (default: @var{connman})
15943 The connman package to use.
15945 @item @code{disable-vpn?} (default: @code{#f})
15946 When true, disable connman's vpn plugin.
15950 @cindex WPA Supplicant
15951 @defvr {Scheme Variable} wpa-supplicant-service-type
15952 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
15953 supplicant}, an authentication daemon required to authenticate against
15954 encrypted WiFi or ethernet networks.
15957 @deftp {Data Type} wpa-supplicant-configuration
15958 Data type representing the configuration of WPA Supplicant.
15960 It takes the following parameters:
15963 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
15964 The WPA Supplicant package to use.
15966 @item @code{requirement} (default: @code{'(user-processes loopback syslogd)}
15967 List of services that should be started before WPA Supplicant starts.
15969 @item @code{dbus?} (default: @code{#t})
15970 Whether to listen for requests on D-Bus.
15972 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
15973 Where to store the PID file.
15975 @item @code{interface} (default: @code{#f})
15976 If this is set, it must specify the name of a network interface that
15977 WPA supplicant will control.
15979 @item @code{config-file} (default: @code{#f})
15980 Optional configuration file to use.
15982 @item @code{extra-options} (default: @code{'()})
15983 List of additional command-line arguments to pass to the daemon.
15987 @cindex hostapd service, for Wi-Fi access points
15988 @cindex Wi-Fi access points, hostapd service
15989 @defvr {Scheme Variable} hostapd-service-type
15990 This is the service type to run the @uref{https://w1.fi/hostapd/,
15991 hostapd} daemon to set up WiFi (IEEE 802.11) access points and
15992 authentication servers. Its associated value must be a
15993 @code{hostapd-configuration} as shown below:
15996 ;; Use wlan1 to run the access point for "My Network".
15997 (service hostapd-service-type
15998 (hostapd-configuration
15999 (interface "wlan1")
16000 (ssid "My Network")
16005 @deftp {Data Type} hostapd-configuration
16006 This data type represents the configuration of the hostapd service, with
16007 the following fields:
16010 @item @code{package} (default: @code{hostapd})
16011 The hostapd package to use.
16013 @item @code{interface} (default: @code{"wlan0"})
16014 The network interface to run the WiFi access point.
16017 The SSID (@dfn{service set identifier}), a string that identifies this
16020 @item @code{broadcast-ssid?} (default: @code{#t})
16021 Whether to broadcast this SSID.
16023 @item @code{channel} (default: @code{1})
16024 The WiFi channel to use.
16026 @item @code{driver} (default: @code{"nl80211"})
16027 The driver interface type. @code{"nl80211"} is used with all Linux
16028 mac80211 drivers. Use @code{"none"} if building hostapd as a standalone
16029 RADIUS server that does # not control any wireless/wired driver.
16031 @item @code{extra-settings} (default: @code{""})
16032 Extra settings to append as-is to the hostapd configuration file. See
16033 @uref{https://w1.fi/cgit/hostap/plain/hostapd/hostapd.conf} for the
16034 configuration file reference.
16038 @defvr {Scheme Variable} simulated-wifi-service-type
16039 This is the type of a service to simulate WiFi networking, which can be
16040 useful in virtual machines for testing purposes. The service loads the
16042 @uref{https://www.kernel.org/doc/html/latest/networking/mac80211_hwsim/mac80211_hwsim.html,
16043 @code{mac80211_hwsim} module} and starts hostapd to create a pseudo WiFi
16044 network that can be seen on @code{wlan0}, by default.
16046 The service's value is a @code{hostapd-configuration} record.
16050 @defvr {Scheme Variable} iptables-service-type
16051 This is the service type to set up an iptables configuration. iptables is a
16052 packet filtering framework supported by the Linux kernel. This service
16053 supports configuring iptables for both IPv4 and IPv6. A simple example
16054 configuration rejecting all incoming connections except those to the ssh port
16058 (service iptables-service-type
16059 (iptables-configuration
16060 (ipv4-rules (plain-file "iptables.rules" "*filter
16064 -A INPUT -p tcp --dport 22 -j ACCEPT
16065 -A INPUT -j REJECT --reject-with icmp-port-unreachable
16068 (ipv6-rules (plain-file "ip6tables.rules" "*filter
16072 -A INPUT -p tcp --dport 22 -j ACCEPT
16073 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
16079 @deftp {Data Type} iptables-configuration
16080 The data type representing the configuration of iptables.
16083 @item @code{iptables} (default: @code{iptables})
16084 The iptables package that provides @code{iptables-restore} and
16085 @code{ip6tables-restore}.
16086 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
16087 The iptables rules to use. It will be passed to @code{iptables-restore}.
16088 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
16090 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
16091 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
16092 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
16098 @defvr {Scheme Variable} nftables-service-type
16099 This is the service type to set up a nftables configuration. nftables is a
16100 netfilter project that aims to replace the existing iptables, ip6tables,
16101 arptables and ebtables framework. It provides a new packet filtering
16102 framework, a new user-space utility @command{nft}, and a compatibility layer
16103 for iptables. This service comes with a default ruleset
16104 @code{%default-nftables-ruleset} that rejecting all incomming connections
16105 except those to the ssh port 22. To use it, simply write:
16108 (service nftables-service-type)
16112 @deftp {Data Type} nftables-configuration
16113 The data type representing the configuration of nftables.
16116 @item @code{package} (default: @code{nftables})
16117 The nftables package that provides @command{nft}.
16118 @item @code{ruleset} (default: @code{%default-nftables-ruleset})
16119 The nftables ruleset to use. This may be any ``file-like'' object
16120 (@pxref{G-Expressions, file-like objects}).
16124 @cindex NTP (Network Time Protocol), service
16125 @cindex ntpd, service for the Network Time Protocol daemon
16126 @cindex real time clock
16127 @defvr {Scheme Variable} ntp-service-type
16128 This is the type of the service running the @uref{https://www.ntp.org,
16129 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
16130 system clock synchronized with that of the specified NTP servers.
16132 The value of this service is an @code{ntpd-configuration} object, as described
16136 @deftp {Data Type} ntp-configuration
16137 This is the data type for the NTP service configuration.
16140 @item @code{servers} (default: @code{%ntp-servers})
16141 This is the list of servers (@code{<ntp-server>} records) with which
16142 @command{ntpd} will be synchronized. See the @code{ntp-server} data type
16145 @item @code{allow-large-adjustment?} (default: @code{#t})
16146 This determines whether @command{ntpd} is allowed to make an initial
16147 adjustment of more than 1,000 seconds.
16149 @item @code{ntp} (default: @code{ntp})
16150 The NTP package to use.
16154 @defvr {Scheme Variable} %ntp-servers
16155 List of host names used as the default NTP servers. These are servers of the
16156 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
16159 @deftp {Data Type} ntp-server
16160 The data type representing the configuration of a NTP server.
16163 @item @code{type} (default: @code{'server})
16164 The type of the NTP server, given as a symbol. One of @code{'pool},
16165 @code{'server}, @code{'peer}, @code{'broadcast} or @code{'manycastclient}.
16167 @item @code{address}
16168 The address of the server, as a string.
16170 @item @code{options}
16171 NTPD options to use with that specific server, given as a list of option names
16172 and/or of option names and values tuples. The following example define a server
16173 to use with the options @option{iburst} and @option{prefer}, as well as
16174 @option{version} 3 and a @option{maxpoll} time of 16 seconds.
16179 (address "some.ntp.server.org")
16180 (options `(iburst (version 3) (maxpoll 16) prefer))))
16186 @deffn {Scheme Procedure} openntpd-service-type
16187 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
16188 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
16189 clock synchronized with that of the given servers.
16193 openntpd-service-type
16194 (openntpd-configuration
16195 (listen-on '("127.0.0.1" "::1"))
16196 (sensor '("udcf0 correction 70000"))
16197 (constraint-from '("www.gnu.org"))
16198 (constraints-from '("https://www.google.com/"))
16199 (allow-large-adjustment? #t)))
16204 @defvr {Scheme Variable} %openntpd-servers
16205 This variable is a list of the server addresses defined in
16206 @code{%ntp-servers}.
16209 @deftp {Data Type} openntpd-configuration
16211 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
16212 The openntpd executable to use.
16213 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
16214 A list of local IP addresses or hostnames the ntpd daemon should listen on.
16215 @item @code{query-from} (default: @code{'()})
16216 A list of local IP address the ntpd daemon should use for outgoing queries.
16217 @item @code{sensor} (default: @code{'()})
16218 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
16219 will listen to each sensor that actually exists and ignore non-existent ones.
16220 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
16222 @item @code{server} (default: @code{'()})
16223 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
16224 @item @code{servers} (default: @code{%openntp-servers})
16225 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
16226 @item @code{constraint-from} (default: @code{'()})
16227 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
16228 This time information is not used for precision but acts as an authenticated
16229 constraint, thereby reducing the impact of unauthenticated NTP
16230 man-in-the-middle attacks.
16231 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
16233 @item @code{constraints-from} (default: @code{'()})
16234 As with constraint from, specify a list of URLs, IP addresses or hostnames of
16235 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
16236 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
16237 @item @code{allow-large-adjustment?} (default: @code{#f})
16238 Determines if @code{ntpd} is allowed to make an initial adjustment of more
16244 @deffn {Scheme variable} inetd-service-type
16245 This service runs the @command{inetd} (@pxref{inetd invocation,,,
16246 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
16247 connections on internet sockets, and lazily starts the specified server
16248 program when a connection is made on one of these sockets.
16250 The value of this service is an @code{inetd-configuration} object. The
16251 following example configures the @command{inetd} daemon to provide the
16252 built-in @command{echo} service, as well as an smtp service which
16253 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
16254 gateway @code{hostname}:
16259 (inetd-configuration
16263 (socket-type 'stream)
16270 (socket-type 'stream)
16274 (program (file-append openssh "/bin/ssh"))
16276 '("ssh" "-qT" "-i" "/path/to/ssh_key"
16277 "-W" "smtp-server:25" "user@@hostname")))))))
16280 See below for more details about @code{inetd-configuration}.
16283 @deftp {Data Type} inetd-configuration
16284 Data type representing the configuration of @command{inetd}.
16287 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
16288 The @command{inetd} executable to use.
16290 @item @code{entries} (default: @code{'()})
16291 A list of @command{inetd} service entries. Each entry should be created
16292 by the @code{inetd-entry} constructor.
16296 @deftp {Data Type} inetd-entry
16297 Data type representing an entry in the @command{inetd} configuration.
16298 Each entry corresponds to a socket where @command{inetd} will listen for
16302 @item @code{node} (default: @code{#f})
16303 Optional string, a comma-separated list of local addresses
16304 @command{inetd} should use when listening for this service.
16305 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
16306 description of all options.
16308 A string, the name must correspond to an entry in @code{/etc/services}.
16309 @item @code{socket-type}
16310 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
16312 @item @code{protocol}
16313 A string, must correspond to an entry in @code{/etc/protocols}.
16314 @item @code{wait?} (default: @code{#t})
16315 Whether @command{inetd} should wait for the server to exit before
16316 listening to new service requests.
16318 A string containing the user (and, optionally, group) name of the user
16319 as whom the server should run. The group name can be specified in a
16320 suffix, separated by a colon or period, i.e.@: @code{"user"},
16321 @code{"user:group"} or @code{"user.group"}.
16322 @item @code{program} (default: @code{"internal"})
16323 The server program which will serve the requests, or @code{"internal"}
16324 if @command{inetd} should use a built-in service.
16325 @item @code{arguments} (default: @code{'()})
16326 A list strings or file-like objects, which are the server program's
16327 arguments, starting with the zeroth argument, i.e.@: the name of the
16328 program itself. For @command{inetd}'s internal services, this entry
16329 must be @code{'()} or @code{'("internal")}.
16332 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
16333 detailed discussion of each configuration field.
16337 @defvr {Scheme Variable} tor-service-type
16338 This is the type for a service that runs the @uref{https://torproject.org,
16339 Tor} anonymous networking daemon. The service is configured using a
16340 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
16341 @code{tor} unprivileged user, which is a member of the @code{tor} group.
16345 @deftp {Data Type} tor-configuration
16347 @item @code{tor} (default: @code{tor})
16348 The package that provides the Tor daemon. This package is expected to provide
16349 the daemon at @file{bin/tor} relative to its output directory. The default
16350 package is the @uref{https://www.torproject.org, Tor Project's}
16353 @item @code{config-file} (default: @code{(plain-file "empty" "")})
16354 The configuration file to use. It will be appended to a default configuration
16355 file, and the final configuration file will be passed to @code{tor} via its
16356 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
16357 file-like objects}). See @code{man tor} for details on the configuration file
16360 @item @code{hidden-services} (default: @code{'()})
16361 The list of @code{<hidden-service>} records to use. For any hidden service
16362 you include in this list, appropriate configuration to enable the hidden
16363 service will be automatically added to the default configuration file. You
16364 may conveniently create @code{<hidden-service>} records using the
16365 @code{tor-hidden-service} procedure described below.
16367 @item @code{socks-socket-type} (default: @code{'tcp})
16368 The default socket type that Tor should use for its SOCKS socket. This must
16369 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
16370 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
16371 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
16372 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
16375 If you want to customize the SOCKS socket in more detail, leave
16376 @code{socks-socket-type} at its default value of @code{'tcp} and use
16377 @code{config-file} to override the default by providing your own
16378 @code{SocksPort} option.
16382 @cindex hidden service
16383 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
16384 Define a new Tor @dfn{hidden service} called @var{name} and implementing
16385 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
16388 '((22 "127.0.0.1:22")
16389 (80 "127.0.0.1:8080"))
16392 In this example, port 22 of the hidden service is mapped to local port 22, and
16393 port 80 is mapped to local port 8080.
16395 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
16396 the @file{hostname} file contains the @code{.onion} host name for the hidden
16399 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
16400 project's documentation} for more information.
16403 The @code{(gnu services rsync)} module provides the following services:
16405 You might want an rsync daemon if you have files that you want available
16406 so anyone (or just yourself) can download existing files or upload new
16409 @deffn {Scheme Variable} rsync-service-type
16410 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
16411 The value for this service type is a
16412 @command{rsync-configuration} record as in this example:
16415 (service rsync-service-type)
16418 See below for details about @code{rsync-configuration}.
16421 @deftp {Data Type} rsync-configuration
16422 Data type representing the configuration for @code{rsync-service}.
16425 @item @code{package} (default: @var{rsync})
16426 @code{rsync} package to use.
16428 @item @code{port-number} (default: @code{873})
16429 TCP port on which @command{rsync} listens for incoming connections. If port
16430 is less than @code{1024} @command{rsync} needs to be started as the
16431 @code{root} user and group.
16433 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
16434 Name of the file where @command{rsync} writes its PID.
16436 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
16437 Name of the file where @command{rsync} writes its lock file.
16439 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
16440 Name of the file where @command{rsync} writes its log file.
16442 @item @code{use-chroot?} (default: @var{#t})
16443 Whether to use chroot for @command{rsync} shared directory.
16445 @item @code{share-path} (default: @file{/srv/rsync})
16446 Location of the @command{rsync} shared directory.
16448 @item @code{share-comment} (default: @code{"Rsync share"})
16449 Comment of the @command{rsync} shared directory.
16451 @item @code{read-only?} (default: @var{#f})
16452 Read-write permissions to shared directory.
16454 @item @code{timeout} (default: @code{300})
16455 I/O timeout in seconds.
16457 @item @code{user} (default: @var{"root"})
16458 Owner of the @code{rsync} process.
16460 @item @code{group} (default: @var{"root"})
16461 Group of the @code{rsync} process.
16463 @item @code{uid} (default: @var{"rsyncd"})
16464 User name or user ID that file transfers to and from that module should take
16465 place as when the daemon was run as @code{root}.
16467 @item @code{gid} (default: @var{"rsyncd"})
16468 Group name or group ID that will be used when accessing the module.
16473 Furthermore, @code{(gnu services ssh)} provides the following services.
16477 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
16478 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
16479 [#:allow-empty-passwords? #f] [#:root-login? #f] @
16480 [#:syslog-output? #t] [#:x11-forwarding? #t] @
16481 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
16482 [#:public-key-authentication? #t] [#:initialize? #t]
16483 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
16484 @var{host-key} must designate a file containing the host key, and readable
16487 When @var{daemonic?} is true, @command{lshd} will detach from the
16488 controlling terminal and log its output to syslogd, unless one sets
16489 @var{syslog-output?} to false. Obviously, it also makes lsh-service
16490 depend on existence of syslogd service. When @var{pid-file?} is true,
16491 @command{lshd} writes its PID to the file called @var{pid-file}.
16493 When @var{initialize?} is true, automatically create the seed and host key
16494 upon service activation if they do not exist yet. This may take long and
16495 require interaction.
16497 When @var{initialize?} is false, it is up to the user to initialize the
16498 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
16499 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
16500 basics,,, lsh, LSH Manual}).
16502 When @var{interfaces} is empty, lshd listens for connections on all the
16503 network interfaces; otherwise, @var{interfaces} must be a list of host names
16506 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
16507 passwords, and @var{root-login?} specifies whether to accept log-ins as
16510 The other options should be self-descriptive.
16515 @deffn {Scheme Variable} openssh-service-type
16516 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
16517 shell daemon, @command{sshd}. Its value must be an
16518 @code{openssh-configuration} record as in this example:
16521 (service openssh-service-type
16522 (openssh-configuration
16523 (x11-forwarding? #t)
16524 (permit-root-login 'without-password)
16526 `(("alice" ,(local-file "alice.pub"))
16527 ("bob" ,(local-file "bob.pub"))))))
16530 See below for details about @code{openssh-configuration}.
16532 This service can be extended with extra authorized keys, as in this
16536 (service-extension openssh-service-type
16537 (const `(("charlie"
16538 ,(local-file "charlie.pub")))))
16542 @deftp {Data Type} openssh-configuration
16543 This is the configuration record for OpenSSH's @command{sshd}.
16546 @item @code{openssh} (default @var{openssh})
16547 The Openssh package to use.
16549 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
16550 Name of the file where @command{sshd} writes its PID.
16552 @item @code{port-number} (default: @code{22})
16553 TCP port on which @command{sshd} listens for incoming connections.
16555 @item @code{permit-root-login} (default: @code{#f})
16556 This field determines whether and when to allow logins as root. If
16557 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
16558 If it's the symbol @code{'without-password}, then root logins are
16559 permitted but not with password-based authentication.
16561 @item @code{allow-empty-passwords?} (default: @code{#f})
16562 When true, users with empty passwords may log in. When false, they may
16565 @item @code{password-authentication?} (default: @code{#t})
16566 When true, users may log in with their password. When false, they have
16567 other authentication methods.
16569 @item @code{public-key-authentication?} (default: @code{#t})
16570 When true, users may log in using public key authentication. When
16571 false, users have to use other authentication method.
16573 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
16574 This is used only by protocol version 2.
16576 @item @code{x11-forwarding?} (default: @code{#f})
16577 When true, forwarding of X11 graphical client connections is
16578 enabled---in other words, @command{ssh} options @option{-X} and
16579 @option{-Y} will work.
16581 @item @code{allow-agent-forwarding?} (default: @code{#t})
16582 Whether to allow agent forwarding.
16584 @item @code{allow-tcp-forwarding?} (default: @code{#t})
16585 Whether to allow TCP forwarding.
16587 @item @code{gateway-ports?} (default: @code{#f})
16588 Whether to allow gateway ports.
16590 @item @code{challenge-response-authentication?} (default: @code{#f})
16591 Specifies whether challenge response authentication is allowed (e.g.@: via
16594 @item @code{use-pam?} (default: @code{#t})
16595 Enables the Pluggable Authentication Module interface. If set to
16596 @code{#t}, this will enable PAM authentication using
16597 @code{challenge-response-authentication?} and
16598 @code{password-authentication?}, in addition to PAM account and session
16599 module processing for all authentication types.
16601 Because PAM challenge response authentication usually serves an
16602 equivalent role to password authentication, you should disable either
16603 @code{challenge-response-authentication?} or
16604 @code{password-authentication?}.
16606 @item @code{print-last-log?} (default: @code{#t})
16607 Specifies whether @command{sshd} should print the date and time of the
16608 last user login when a user logs in interactively.
16610 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
16611 Configures external subsystems (e.g.@: file transfer daemon).
16613 This is a list of two-element lists, each of which containing the
16614 subsystem name and a command (with optional arguments) to execute upon
16617 The command @command{internal-sftp} implements an in-process SFTP
16618 server. Alternatively, one can specify the @command{sftp-server} command:
16620 (service openssh-service-type
16621 (openssh-configuration
16623 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
16626 @item @code{accepted-environment} (default: @code{'()})
16627 List of strings describing which environment variables may be exported.
16629 Each string gets on its own line. See the @code{AcceptEnv} option in
16630 @code{man sshd_config}.
16632 This example allows ssh-clients to export the @env{COLORTERM} variable.
16633 It is set by terminal emulators, which support colors. You can use it in
16634 your shell's resource file to enable colors for the prompt and commands
16635 if this variable is set.
16638 (service openssh-service-type
16639 (openssh-configuration
16640 (accepted-environment '("COLORTERM"))))
16643 @item @code{authorized-keys} (default: @code{'()})
16644 @cindex authorized keys, SSH
16645 @cindex SSH authorized keys
16646 This is the list of authorized keys. Each element of the list is a user
16647 name followed by one or more file-like objects that represent SSH public
16651 (openssh-configuration
16653 `(("rekado" ,(local-file "rekado.pub"))
16654 ("chris" ,(local-file "chris.pub"))
16655 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
16659 registers the specified public keys for user accounts @code{rekado},
16660 @code{chris}, and @code{root}.
16662 Additional authorized keys can be specified @i{via}
16663 @code{service-extension}.
16665 Note that this does @emph{not} interfere with the use of
16666 @file{~/.ssh/authorized_keys}.
16668 @item @code{log-level} (default: @code{'info})
16669 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
16670 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
16671 page for @file{sshd_config} for the full list of level names.
16673 @item @code{extra-content} (default: @code{""})
16674 This field can be used to append arbitrary text to the configuration file. It
16675 is especially useful for elaborate configurations that cannot be expressed
16676 otherwise. This configuration, for example, would generally disable root
16677 logins, but permit them from one specific IP address:
16680 (openssh-configuration
16682 Match Address 192.168.0.1
16683 PermitRootLogin yes"))
16689 @deffn {Scheme Procedure} dropbear-service [@var{config}]
16690 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
16691 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
16694 For example, to specify a Dropbear service listening on port 1234, add
16695 this call to the operating system's @code{services} field:
16698 (dropbear-service (dropbear-configuration
16699 (port-number 1234)))
16703 @deftp {Data Type} dropbear-configuration
16704 This data type represents the configuration of a Dropbear SSH daemon.
16707 @item @code{dropbear} (default: @var{dropbear})
16708 The Dropbear package to use.
16710 @item @code{port-number} (default: 22)
16711 The TCP port where the daemon waits for incoming connections.
16713 @item @code{syslog-output?} (default: @code{#t})
16714 Whether to enable syslog output.
16716 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
16717 File name of the daemon's PID file.
16719 @item @code{root-login?} (default: @code{#f})
16720 Whether to allow @code{root} logins.
16722 @item @code{allow-empty-passwords?} (default: @code{#f})
16723 Whether to allow empty passwords.
16725 @item @code{password-authentication?} (default: @code{#t})
16726 Whether to enable password-based authentication.
16731 @deffn {Scheme Variable} autossh-service-type
16732 This is the type for the @uref{https://www.harding.motd.ca/autossh,
16733 AutoSSH} program that runs a copy of @command{ssh} and monitors it,
16734 restarting it as necessary should it die or stop passing traffic.
16735 AutoSSH can be run manually from the command-line by passing arguments
16736 to the binary @command{autossh} from the package @code{autossh}, but it
16737 can also be run as a Guix service. This latter use case is documented
16740 AutoSSH can be used to forward local traffic to a remote machine using
16741 an SSH tunnel, and it respects the @file{~/.ssh/config} of the user it
16744 For example, to specify a service running autossh as the user
16745 @code{pino} and forwarding all local connections to port @code{8081} to
16746 @code{remote:8081} using an SSH tunnel, add this call to the operating
16747 system's @code{services} field:
16750 (service autossh-service-type
16751 (autossh-configuration
16753 (ssh-options (list "-T" "-N" "-L" "8081:localhost:8081" "remote.net"))))
16757 @deftp {Data Type} autossh-configuration
16758 This data type represents the configuration of an AutoSSH service.
16762 @item @code{user} (default @code{"autossh"})
16763 The user as which the AutoSSH service is to be run.
16764 This assumes that the specified user exists.
16766 @item @code{poll} (default @code{600})
16767 Specifies the connection poll time in seconds.
16769 @item @code{first-poll} (default @code{#f})
16770 Specifies how many seconds AutoSSH waits before the first connection
16771 test. After this first test, polling is resumed at the pace defined in
16772 @code{poll}. When set to @code{#f}, the first poll is not treated
16773 specially and will also use the connection poll specified in
16776 @item @code{gate-time} (default @code{30})
16777 Specifies how many seconds an SSH connection must be active before it is
16778 considered successful.
16780 @item @code{log-level} (default @code{1})
16781 The log level, corresponding to the levels used by syslog---so @code{0}
16782 is the most silent while @code{7} is the chattiest.
16784 @item @code{max-start} (default @code{#f})
16785 The maximum number of times SSH may be (re)started before AutoSSH exits.
16786 When set to @code{#f}, no maximum is configured and AutoSSH may restart indefinitely.
16788 @item @code{message} (default @code{""})
16789 The message to append to the echo message sent when testing connections.
16791 @item @code{port} (default @code{"0"})
16792 The ports used for monitoring the connection. When set to @code{"0"},
16793 monitoring is disabled. When set to @code{"@var{n}"} where @var{n} is
16794 a positive integer, ports @var{n} and @var{n}+1 are used for
16795 monitoring the connection, such that port @var{n} is the base
16796 monitoring port and @code{n+1} is the echo port. When set to
16797 @code{"@var{n}:@var{m}"} where @var{n} and @var{m} are positive
16798 integers, the ports @var{n} and @var{m} are used for monitoring the
16799 connection, such that port @var{n} is the base monitoring port and
16800 @var{m} is the echo port.
16802 @item @code{ssh-options} (default @code{'()})
16803 The list of command-line arguments to pass to @command{ssh} when it is
16804 run. Options @option{-f} and @option{-M} are reserved for AutoSSH and
16805 may cause undefined behaviour.
16811 @deffn {Scheme Variable} webssh-service-type
16812 This is the type for the @uref{https://webssh.huashengdun.org/, WebSSH}
16813 program that runs a web SSH client. WebSSH can be run manually from the
16814 command-line by passing arguments to the binary @command{wssh} from the
16815 package @code{webssh}, but it can also be run as a Guix service. This
16816 latter use case is documented here.
16818 For example, to specify a service running WebSSH on loopback interface
16819 on port @code{8888} with reject policy with a list of allowed to
16820 connection hosts, and NGINX as a reverse-proxy to this service listening
16821 for HTTPS connection, add this call to the operating system's
16822 @code{services} field:
16825 (service webssh-service-type
16826 (webssh-configuration (address "127.0.0.1")
16829 (known-hosts '("localhost ecdsa-sha2-nistp256 AAAA…"
16830 "127.0.0.1 ecdsa-sha2-nistp256 AAAA…"))))
16832 (service nginx-service-type
16833 (nginx-configuration
16836 (nginx-server-configuration
16837 (inherit %webssh-configuration-nginx)
16838 (server-name '("webssh.example.com"))
16839 (listen '("443 ssl"))
16840 (ssl-certificate (letsencrypt-certificate "webssh.example.com"))
16841 (ssl-certificate-key (letsencrypt-key "webssh.example.com"))
16843 (cons (nginx-location-configuration
16844 (uri "/.well-known")
16845 (body '("root /var/www;")))
16846 (nginx-server-configuration-locations %webssh-configuration-nginx))))))))
16850 @deftp {Data Type} webssh-configuration
16851 Data type representing the configuration for @code{webssh-service}.
16854 @item @code{package} (default: @var{webssh})
16855 @code{webssh} package to use.
16857 @item @code{user-name} (default: @var{"webssh"})
16858 User name or user ID that file transfers to and from that module should take
16861 @item @code{group-name} (default: @var{"webssh"})
16862 Group name or group ID that will be used when accessing the module.
16864 @item @code{address} (default: @var{#f})
16865 IP address on which @command{webssh} listens for incoming connections.
16867 @item @code{port} (default: @var{8888})
16868 TCP port on which @command{webssh} listens for incoming connections.
16870 @item @code{policy} (default: @var{#f})
16871 Connection policy. @var{reject} policy requires to specify @var{known-hosts}.
16873 @item @code{known-hosts} (default: @var{'()})
16874 List of hosts which allowed for SSH connection from @command{webssh}.
16876 @item @code{log-file} (default: @file{"/var/log/webssh.log"})
16877 Name of the file where @command{webssh} writes its log file.
16879 @item @code{log-level} (default: @var{#f})
16885 @defvr {Scheme Variable} %facebook-host-aliases
16886 This variable contains a string for use in @file{/etc/hosts}
16887 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
16888 line contains a entry that maps a known server name of the Facebook
16889 on-line service---e.g., @code{www.facebook.com}---to the local
16890 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
16892 This variable is typically used in the @code{hosts-file} field of an
16893 @code{operating-system} declaration (@pxref{operating-system Reference,
16894 @file{/etc/hosts}}):
16897 (use-modules (gnu) (guix))
16900 (host-name "mymachine")
16903 ;; Create a /etc/hosts file with aliases for "localhost"
16904 ;; and "mymachine", as well as for Facebook servers.
16905 (plain-file "hosts"
16906 (string-append (local-host-aliases host-name)
16907 %facebook-host-aliases))))
16910 This mechanism can prevent programs running locally, such as Web
16911 browsers, from accessing Facebook.
16914 The @code{(gnu services avahi)} provides the following definition.
16916 @defvr {Scheme Variable} avahi-service-type
16917 This is the service that runs @command{avahi-daemon}, a system-wide
16918 mDNS/DNS-SD responder that allows for service discovery and
16919 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
16920 Its value must be an @code{avahi-configuration} record---see below.
16922 This service extends the name service cache daemon (nscd) so that it can
16923 resolve @code{.local} host names using
16924 @uref{https://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
16925 Service Switch}, for information on host name resolution.
16927 Additionally, add the @var{avahi} package to the system profile so that
16928 commands such as @command{avahi-browse} are directly usable.
16931 @deftp {Data Type} avahi-configuration
16932 Data type representation the configuration for Avahi.
16936 @item @code{host-name} (default: @code{#f})
16937 If different from @code{#f}, use that as the host name to
16938 publish for this machine; otherwise, use the machine's actual host name.
16940 @item @code{publish?} (default: @code{#t})
16941 When true, allow host names and services to be published (broadcast) over the
16944 @item @code{publish-workstation?} (default: @code{#t})
16945 When true, @command{avahi-daemon} publishes the machine's host name and IP
16946 address via mDNS on the local network. To view the host names published on
16947 your local network, you can run:
16950 avahi-browse _workstation._tcp
16953 @item @code{wide-area?} (default: @code{#f})
16954 When true, DNS-SD over unicast DNS is enabled.
16956 @item @code{ipv4?} (default: @code{#t})
16957 @itemx @code{ipv6?} (default: @code{#t})
16958 These fields determine whether to use IPv4/IPv6 sockets.
16960 @item @code{domains-to-browse} (default: @code{'()})
16961 This is a list of domains to browse.
16965 @deffn {Scheme Variable} openvswitch-service-type
16966 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
16967 service, whose value should be an @code{openvswitch-configuration}
16971 @deftp {Data Type} openvswitch-configuration
16972 Data type representing the configuration of Open vSwitch, a multilayer
16973 virtual switch which is designed to enable massive network automation
16974 through programmatic extension.
16977 @item @code{package} (default: @var{openvswitch})
16978 Package object of the Open vSwitch.
16983 @defvr {Scheme Variable} pagekite-service-type
16984 This is the service type for the @uref{https://pagekite.net, PageKite} service,
16985 a tunneling solution for making localhost servers publicly visible, even from
16986 behind restrictive firewalls or NAT without forwarded ports. The value for
16987 this service type is a @code{pagekite-configuration} record.
16989 Here's an example exposing the local HTTP and SSH daemons:
16992 (service pagekite-service-type
16993 (pagekite-configuration
16994 (kites '("http:@@kitename:localhost:80:@@kitesecret"
16995 "raw/22:@@kitename:localhost:22:@@kitesecret"))
16996 (extra-file "/etc/pagekite.rc")))
17000 @deftp {Data Type} pagekite-configuration
17001 Data type representing the configuration of PageKite.
17004 @item @code{package} (default: @var{pagekite})
17005 Package object of PageKite.
17007 @item @code{kitename} (default: @code{#f})
17008 PageKite name for authenticating to the frontend server.
17010 @item @code{kitesecret} (default: @code{#f})
17011 Shared secret for authenticating to the frontend server. You should probably
17012 put this inside @code{extra-file} instead.
17014 @item @code{frontend} (default: @code{#f})
17015 Connect to the named PageKite frontend server instead of the
17016 @uref{https://pagekite.net,,pagekite.net} service.
17018 @item @code{kites} (default: @code{'("http:@@kitename:localhost:80:@@kitesecret")})
17019 List of service kites to use. Exposes HTTP on port 80 by default. The format
17020 is @code{proto:kitename:host:port:secret}.
17022 @item @code{extra-file} (default: @code{#f})
17023 Extra configuration file to read, which you are expected to create manually.
17024 Use this to add additional options and manage shared secrets out-of-band.
17029 @defvr {Scheme Variable} yggdrasil-service-type
17030 The service type for connecting to the @uref{https://yggdrasil-network.github.io/,
17031 Yggdrasil network}, an early-stage implementation of a fully end-to-end
17032 encrypted IPv6 network.
17035 Yggdrasil provides name-independent routing with cryptographically generated
17036 addresses. Static addressing means you can keep the same address as long as
17037 you want, even if you move to a new location, or generate a new address (by
17038 generating new keys) whenever you want.
17039 @uref{https://yggdrasil-network.github.io/2018/07/28/addressing.html}
17042 Pass it a value of @code{yggdrasil-configuration} to connect it to public
17043 peers and/or local peers.
17045 Here is an example using public peers and a static address. The static
17046 signing and encryption keys are defined in @file{/etc/yggdrasil-private.conf}
17047 (the default value for @code{config-file}).
17050 ;; part of the operating-system declaration
17051 (service yggdrasil-service-type
17052 (yggdrasil-configuration
17053 (autoconf? #f) ;; use only the public peers
17056 ;; https://github.com/yggdrasil-network/public-peers
17057 '((peers . #("tcp://1.2.3.4:1337"))))
17058 ;; /etc/yggdrasil-private.conf is the default value for config-file
17062 # sample content for /etc/yggdrasil-private.conf
17064 # Your public encryption key. Your peers may ask you for this to put
17065 # into their AllowedEncryptionPublicKeys configuration.
17066 EncryptionPublicKey: 378dc5...
17068 # Your private encryption key. DO NOT share this with anyone!
17069 EncryptionPrivateKey: 0777...
17071 # Your public signing key. You should not ordinarily need to share
17072 # this with anyone.
17073 SigningPublicKey: e1664...
17075 # Your private signing key. DO NOT share this with anyone!
17076 SigningPrivateKey: 0589d...
17081 @deftp {Data Type} yggdrasil-configuration
17082 Data type representing the configuration of Yggdrasil.
17085 @item @code{package} (default: @code{yggdrasil})
17086 Package object of Yggdrasil.
17088 @item @code{json-config} (default: @code{'()})
17089 Contents of @file{/etc/yggdrasil.conf}. Will be merged with
17090 @file{/etc/yggdrasil-private.conf}. Note that these settings are stored in
17091 the Guix store, which is readable to all users. @strong{Do not store your
17092 private keys in it}. See the output of @code{yggdrasil -genconf} for a
17093 quick overview of valid keys and their default values.
17095 @item @code{autoconf?} (default: @code{#f})
17096 Whether to use automatic mode. Enabling it makes Yggdrasil use adynamic IP
17097 and peer with IPv6 neighbors.
17099 @item @code{log-level} (default: @code{'info})
17100 How much detail to include in logs. Use @code{'debug} for more detail.
17102 @item @code{log-to} (default: @code{'stdout})
17103 Where to send logs. By default, the service logs standard output to
17104 @file{/var/log/yggdrasil.log}. The alternative is @code{'syslog}, which
17105 sends output to the running syslog service.
17107 @item @code{config-file} (default: @code{"/etc/yggdrasil-private.conf"})
17108 What HJSON file to load sensitive data from. This is where private keys
17109 should be stored, which are necessary to specify if you don't want a
17110 randomized address after each restart. Use @code{#f} to disable. Options
17111 defined in this file take precedence over @code{json-config}. Use the output
17112 of @code{yggdrasil -genconf} as a starting point. To configure a static
17113 address, delete everything except these options:
17116 @item @code{EncryptionPublicKey}
17117 @item @code{EncryptionPrivateKey}
17118 @item @code{SigningPublicKey}
17119 @item @code{SigningPrivateKey}
17124 @node Unattended Upgrades
17125 @subsection Unattended Upgrades
17127 @cindex unattended upgrades
17128 @cindex upgrades, unattended
17129 Guix provides a service to perform @emph{unattended upgrades}:
17130 periodically, the system automatically reconfigures itself from the
17131 latest Guix. Guix System has several properties that make unattended
17136 upgrades are transactional (either the upgrade succeeds or it fails, but
17137 you cannot end up with an ``in-between'' system state);
17139 the upgrade log is kept---you can view it with @command{guix system
17140 list-generations}---and you can roll back to any previous generation,
17141 should the upgraded system fail to behave as intended;
17143 channel code is authenticated so you know you can only run genuine code
17144 (@pxref{Channels});
17146 @command{guix system reconfigure} prevents downgrades, which makes it
17147 immune to @dfn{downgrade attacks}.
17150 To set up unattended upgrades, add an instance of
17151 @code{unattended-upgrade-service-type} like the one below to the list of
17152 your operating system services:
17155 (service unattended-upgrade-service-type)
17158 The defaults above set up weekly upgrades: every Sunday at midnight.
17159 You do not need to provide the operating system configuration file: it
17160 uses @file{/run/current-system/configuration.scm}, which ensures it
17161 always uses your latest configuration---@pxref{provenance-service-type},
17162 for more information about this file.
17164 There are several things that can be configured, in particular the
17165 periodicity and services (daemons) to be restarted upon completion.
17166 When the upgrade is successful, the service takes care of deleting
17167 system generations older that some threshold, as per @command{guix
17168 system delete-generations}. See the reference below for details.
17170 To ensure that upgrades are actually happening, you can run
17171 @command{guix system describe}. To investigate upgrade failures, visit
17172 the unattended upgrade log file (see below).
17174 @defvr {Scheme Variable} unattended-upgrade-service-type
17175 This is the service type for unattended upgrades. It sets up an mcron
17176 job (@pxref{Scheduled Job Execution}) that runs @command{guix system
17177 reconfigure} from the latest version of the specified channels.
17179 Its value must be a @code{unattended-upgrade-configuration} record (see
17183 @deftp {Data Type} unattended-upgrade-configuration
17184 This data type represents the configuration of the unattended upgrade
17185 service. The following fields are available:
17188 @item @code{schedule} (default: @code{"30 01 * * 0"})
17189 This is the schedule of upgrades, expressed as a gexp containing an
17190 mcron job schedule (@pxref{Guile Syntax, mcron job specifications,,
17191 mcron, GNU@tie{}mcron}).
17193 @item @code{channels} (default: @code{#~%default-channels})
17194 This gexp specifies the channels to use for the upgrade
17195 (@pxref{Channels}). By default, the tip of the official @code{guix}
17198 @item @code{operating-system-file} (default: @code{"/run/current-system/configuration.scm"})
17199 This field specifies the operating system configuration file to use.
17200 The default is to reuse the config file of the current configuration.
17202 There are cases, though, where referring to
17203 @file{/run/current-system/configuration.scm} is not enough, for instance
17204 because that file refers to extra files (SSH public keys, extra
17205 configuration files, etc.) @i{via} @code{local-file} and similar
17206 constructs. For those cases, we recommend something along these lines:
17209 (unattended-upgrade-configuration
17210 (operating-system-file
17211 (file-append (local-file "." "config-dir" #:recursive? #t)
17215 The effect here is to import all of the current directory into the
17216 store, and to refer to @file{config.scm} within that directory.
17217 Therefore, uses of @code{local-file} within @file{config.scm} will work
17218 as expected. @xref{G-Expressions}, for information about
17219 @code{local-file} and @code{file-append}.
17221 @item @code{services-to-restart} (default: @code{'(mcron)})
17222 This field specifies the Shepherd services to restart when the upgrade
17225 Those services are restarted right away upon completion, as with
17226 @command{herd restart}, which ensures that the latest version is
17227 running---remember that by default @command{guix system reconfigure}
17228 only restarts services that are not currently running, which is
17229 conservative: it minimizes disruption but leaves outdated services
17232 Use @command{herd status} to find out candidates for restarting.
17233 @xref{Services}, for general information about services. Common
17234 services to restart would include @code{ntpd} and @code{ssh-daemon}.
17236 By default, the @code{mcron} service is restarted. This ensures that
17237 the latest version of the unattended upgrade job will be used next time.
17239 @item @code{system-expiration} (default: @code{(* 3 30 24 3600)})
17240 This is the expiration time in seconds for system generations. System
17241 generations older that this amount of time are deleted with
17242 @command{guix system delete-generations} when an upgrade completes.
17245 The unattended upgrade service does not run the garbage collector. You
17246 will probably want to set up your own mcron job to run @command{guix gc}
17250 @item @code{maximum-duration} (default: @code{3600})
17251 Maximum duration in seconds for the upgrade; past that time, the upgrade
17254 This is primarily useful to ensure the upgrade does not end up
17255 rebuilding or re-downloading ``the world''.
17257 @item @code{log-file} (default: @code{"/var/log/unattended-upgrade.log"})
17258 File where unattended upgrades are logged.
17263 @subsection X Window
17266 @cindex X Window System
17267 @cindex login manager
17268 Support for the X Window graphical display system---specifically
17269 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
17270 there is no @code{xorg-service} procedure. Instead, the X server is
17271 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
17274 @cindex GNOME, login manager
17275 GDM of course allows users to log in into window managers and desktop
17276 environments other than GNOME; for those using GNOME, GDM is required for
17277 features such as automatic screen locking.
17279 @cindex window manager
17280 To use X11, you must install at least one @dfn{window manager}---for
17281 example the @code{windowmaker} or @code{openbox} packages---preferably
17282 by adding it to the @code{packages} field of your operating system
17283 definition (@pxref{operating-system Reference, system-wide packages}).
17285 @defvr {Scheme Variable} gdm-service-type
17286 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
17287 Desktop Manager} (GDM), a program that manages graphical display servers and
17288 handles graphical user logins. Its value must be a @code{gdm-configuration}
17291 @cindex session types (X11)
17292 @cindex X11 session types
17293 GDM looks for @dfn{session types} described by the @file{.desktop} files in
17294 @file{/run/current-system/profile/share/xsessions} and allows users to choose
17295 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
17296 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
17297 set of packages automatically makes them available at the log-in screen.
17299 In addition, @file{~/.xsession} files are honored. When available,
17300 @file{~/.xsession} must be an executable that starts a window manager
17301 and/or other X clients.
17304 @deftp {Data Type} gdm-configuration
17306 @item @code{auto-login?} (default: @code{#f})
17307 @itemx @code{default-user} (default: @code{#f})
17308 When @code{auto-login?} is false, GDM presents a log-in screen.
17310 When @code{auto-login?} is true, GDM logs in directly as
17311 @code{default-user}.
17313 @item @code{debug?} (default: @code{#f})
17314 When true, GDM writes debug messages to its log.
17316 @item @code{gnome-shell-assets} (default: ...)
17317 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
17319 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
17320 Configuration of the Xorg graphical server.
17322 @item @code{xsession} (default: @code{(xinitrc)})
17323 Script to run before starting a X session.
17325 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
17326 File name of the @code{dbus-daemon} executable.
17328 @item @code{gdm} (default: @code{gdm})
17329 The GDM package to use.
17333 @defvr {Scheme Variable} slim-service-type
17334 This is the type for the SLiM graphical login manager for X11.
17336 Like GDM, SLiM looks for session types described by @file{.desktop} files and
17337 allows users to choose a session from the log-in screen using @kbd{F1}. It
17338 also honors @file{~/.xsession} files.
17340 Unlike GDM, SLiM does not spawn the user session on a different VT after
17341 logging in, which means that you can only start one graphical session. If you
17342 want to be able to run multiple graphical sessions at the same time you have
17343 to add multiple SLiM services to your system services. The following example
17344 shows how to replace the default GDM service with two SLiM services on tty7
17348 (use-modules (gnu services)
17349 (gnu services desktop)
17350 (gnu services xorg)
17351 (srfi srfi-1)) ;for 'remove'
17355 (services (cons* (service slim-service-type (slim-configuration
17358 (service slim-service-type (slim-configuration
17361 (remove (lambda (service)
17362 (eq? (service-kind service) gdm-service-type))
17363 %desktop-services))))
17368 @deftp {Data Type} slim-configuration
17369 Data type representing the configuration of @code{slim-service-type}.
17372 @item @code{allow-empty-passwords?} (default: @code{#t})
17373 Whether to allow logins with empty passwords.
17375 @item @code{auto-login?} (default: @code{#f})
17376 @itemx @code{default-user} (default: @code{""})
17377 When @code{auto-login?} is false, SLiM presents a log-in screen.
17379 When @code{auto-login?} is true, SLiM logs in directly as
17380 @code{default-user}.
17382 @item @code{theme} (default: @code{%default-slim-theme})
17383 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
17384 The graphical theme to use and its name.
17386 @item @code{auto-login-session} (default: @code{#f})
17387 If true, this must be the name of the executable to start as the default
17388 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
17390 If false, a session described by one of the available @file{.desktop}
17391 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
17395 You must install at least one window manager in the system profile or in
17396 your user profile. Failing to do that, if @code{auto-login-session} is
17397 false, you will be unable to log in.
17400 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
17401 Configuration of the Xorg graphical server.
17403 @item @code{display} (default @code{":0"})
17404 The display on which to start the Xorg graphical server.
17406 @item @code{vt} (default @code{"vt7"})
17407 The VT on which to start the Xorg graphical server.
17409 @item @code{xauth} (default: @code{xauth})
17410 The XAuth package to use.
17412 @item @code{shepherd} (default: @code{shepherd})
17413 The Shepherd package used when invoking @command{halt} and
17416 @item @code{sessreg} (default: @code{sessreg})
17417 The sessreg package used in order to register the session.
17419 @item @code{slim} (default: @code{slim})
17420 The SLiM package to use.
17424 @defvr {Scheme Variable} %default-theme
17425 @defvrx {Scheme Variable} %default-theme-name
17426 The default SLiM theme and its name.
17430 @deftp {Data Type} sddm-configuration
17431 This is the data type representing the SDDM service configuration.
17434 @item @code{display-server} (default: "x11")
17435 Select display server to use for the greeter. Valid values are
17436 @samp{"x11"} or @samp{"wayland"}.
17438 @item @code{numlock} (default: "on")
17439 Valid values are @samp{"on"}, @samp{"off"} or @samp{"none"}.
17441 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
17442 Command to run when halting.
17444 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
17445 Command to run when rebooting.
17447 @item @code{theme} (default "maldives")
17448 Theme to use. Default themes provided by SDDM are @samp{"elarun"},
17449 @samp{"maldives"} or @samp{"maya"}.
17451 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
17452 Directory to look for themes.
17454 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
17455 Directory to look for faces.
17457 @item @code{default-path} (default "/run/current-system/profile/bin")
17458 Default PATH to use.
17460 @item @code{minimum-uid} (default: 1000)
17461 Minimum UID displayed in SDDM and allowed for log-in.
17463 @item @code{maximum-uid} (default: 2000)
17464 Maximum UID to display in SDDM.
17466 @item @code{remember-last-user?} (default #t)
17467 Remember last user.
17469 @item @code{remember-last-session?} (default #t)
17470 Remember last session.
17472 @item @code{hide-users} (default "")
17473 Usernames to hide from SDDM greeter.
17475 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
17476 Users with shells listed will be hidden from the SDDM greeter.
17478 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
17479 Script to run before starting a wayland session.
17481 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
17482 Directory to look for desktop files starting wayland sessions.
17484 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
17485 Configuration of the Xorg graphical server.
17487 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
17490 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
17493 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
17494 Script to run after starting xorg-server.
17496 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
17497 Script to run before stopping xorg-server.
17499 @item @code{xsession-command} (default: @code{xinitrc})
17500 Script to run before starting a X session.
17502 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
17503 Directory to look for desktop files starting X sessions.
17505 @item @code{minimum-vt} (default: 7)
17508 @item @code{auto-login-user} (default "")
17509 User to use for auto-login.
17511 @item @code{auto-login-session} (default "")
17512 Desktop file to use for auto-login.
17514 @item @code{relogin?} (default #f)
17515 Relogin after logout.
17520 @cindex login manager
17522 @defvr {Scheme Variable} sddm-service-type
17523 This is the type of the service to run the
17524 @uref{https://github.com/sddm/sddm,SDDM display manager}. Its value
17525 must be a @code{sddm-configuration} record (see below).
17527 Here's an example use:
17530 (service sddm-service-type
17531 (sddm-configuration
17532 (auto-login-user "alice")
17533 (auto-login-session "xfce.desktop")))
17537 @deftp {Data Type} sddm-configuration
17538 This data type represents the configuration of the SDDM login manager.
17539 The available fields are:
17542 @item @code{sddm} (default: @code{sddm})
17543 The SDDM package to use.
17545 @item @code{display-server} (default: @code{"x11"})
17546 This must be either @code{"x11"} or @code{"wayland"}.
17548 @c FIXME: Add more fields.
17550 @item @code{auto-login-user} (default: @code{""})
17551 If non-empty, this is the user account under which to log in
17554 @item @code{auto-login-session} (default: @code{""})
17555 If non-empty, this is the @file{.desktop} file name to use as the
17556 auto-login session.
17560 @cindex Xorg, configuration
17561 @deftp {Data Type} xorg-configuration
17562 This data type represents the configuration of the Xorg graphical display
17563 server. Note that there is no Xorg service; instead, the X server is started
17564 by a ``display manager'' such as GDM, SDDM, and SLiM. Thus, the configuration
17565 of these display managers aggregates an @code{xorg-configuration} record.
17568 @item @code{modules} (default: @code{%default-xorg-modules})
17569 This is a list of @dfn{module packages} loaded by the Xorg
17570 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
17572 @item @code{fonts} (default: @code{%default-xorg-fonts})
17573 This is a list of font directories to add to the server's @dfn{font path}.
17575 @item @code{drivers} (default: @code{'()})
17576 This must be either the empty list, in which case Xorg chooses a graphics
17577 driver automatically, or a list of driver names that will be tried in this
17578 order---e.g., @code{("modesetting" "vesa")}.
17580 @item @code{resolutions} (default: @code{'()})
17581 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
17582 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
17585 @cindex keyboard layout, for Xorg
17586 @cindex keymap, for Xorg
17587 @item @code{keyboard-layout} (default: @code{#f})
17588 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
17589 English (``qwerty'') for a 105-key PC keyboard.
17591 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
17592 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
17593 information on how to specify the keyboard layout.
17595 @item @code{extra-config} (default: @code{'()})
17596 This is a list of strings or objects appended to the configuration file. It
17597 is used to pass extra text to be added verbatim to the configuration file.
17599 @item @code{server} (default: @code{xorg-server})
17600 This is the package providing the Xorg server.
17602 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
17603 This is the list of command-line arguments to pass to the X server. The
17604 default is @code{-nolisten tcp}.
17608 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
17609 [@var{login-manager-service-type}]
17610 Tell the log-in manager (of type @var{login-manager-service-type}) to use
17611 @var{config}, an @code{<xorg-configuration>} record.
17613 Since the Xorg configuration is embedded in the log-in manager's
17614 configuration---e.g., @code{gdm-configuration}---this procedure provides a
17615 shorthand to set the Xorg configuration.
17618 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
17619 Return a @code{startx} script in which the modules, fonts, etc. specified
17620 in @var{config}, are available. The result should be used in place of
17623 Usually the X server is started by a login manager.
17627 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
17628 Add @var{package}, a package for a screen locker or screen saver whose
17629 command is @var{program}, to the set of setuid programs and add a PAM entry
17630 for it. For example:
17633 (screen-locker-service xlockmore "xlock")
17636 makes the good ol' XlockMore usable.
17640 @node Printing Services
17641 @subsection Printing Services
17643 @cindex printer support with CUPS
17644 The @code{(gnu services cups)} module provides a Guix service definition
17645 for the CUPS printing service. To add printer support to a Guix
17646 system, add a @code{cups-service} to the operating system definition:
17648 @deffn {Scheme Variable} cups-service-type
17649 The service type for the CUPS print server. Its value should be a valid
17650 CUPS configuration (see below). To use the default settings, simply
17653 (service cups-service-type)
17657 The CUPS configuration controls the basic things about your CUPS
17658 installation: what interfaces it listens on, what to do if a print job
17659 fails, how much logging to do, and so on. To actually add a printer,
17660 you have to visit the @url{http://localhost:631} URL, or use a tool such
17661 as GNOME's printer configuration services. By default, configuring a
17662 CUPS service will generate a self-signed certificate if needed, for
17663 secure connections to the print server.
17665 Suppose you want to enable the Web interface of CUPS and also add
17666 support for Epson printers @i{via} the @code{epson-inkjet-printer-escpr}
17667 package and for HP printers @i{via} the @code{hplip-minimal} package.
17668 You can do that directly, like this (you need to use the
17669 @code{(gnu packages cups)} module):
17672 (service cups-service-type
17673 (cups-configuration
17674 (web-interface? #t)
17676 (list cups-filters epson-inkjet-printer-escpr hplip-minimal))))
17679 Note: If you wish to use the Qt5 based GUI which comes with the hplip
17680 package then it is suggested that you install the @code{hplip} package,
17681 either in your OS configuration file or as your user.
17683 The available configuration parameters follow. Each parameter
17684 definition is preceded by its type; for example, @samp{string-list foo}
17685 indicates that the @code{foo} parameter should be specified as a list of
17686 strings. There is also a way to specify the configuration as a string,
17687 if you have an old @code{cupsd.conf} file that you want to port over
17688 from some other system; see the end for more details.
17690 @c The following documentation was initially generated by
17691 @c (generate-documentation) in (gnu services cups). Manually maintained
17692 @c documentation is better, so we shouldn't hesitate to edit below as
17693 @c needed. However if the change you want to make to this documentation
17694 @c can be done in an automated way, it's probably easier to change
17695 @c (generate-documentation) than to make it below and have to deal with
17696 @c the churn as CUPS updates.
17699 Available @code{cups-configuration} fields are:
17701 @deftypevr {@code{cups-configuration} parameter} package cups
17705 @deftypevr {@code{cups-configuration} parameter} package-list extensions (default: @code{(list epson-inkjet-printer-escpr hplip-minimal foomatic-filters splix)})
17706 Drivers and other extensions to the CUPS package.
17709 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
17710 Configuration of where to write logs, what directories to use for print
17711 spools, and related privileged configuration parameters.
17713 Available @code{files-configuration} fields are:
17715 @deftypevr {@code{files-configuration} parameter} log-location access-log
17716 Defines the access log filename. Specifying a blank filename disables
17717 access log generation. The value @code{stderr} causes log entries to be
17718 sent to the standard error file when the scheduler is running in the
17719 foreground, or to the system log daemon when run in the background. The
17720 value @code{syslog} causes log entries to be sent to the system log
17721 daemon. The server name may be included in filenames using the string
17722 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
17724 Defaults to @samp{"/var/log/cups/access_log"}.
17727 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
17728 Where CUPS should cache data.
17730 Defaults to @samp{"/var/cache/cups"}.
17733 @deftypevr {@code{files-configuration} parameter} string config-file-perm
17734 Specifies the permissions for all configuration files that the scheduler
17737 Note that the permissions for the printers.conf file are currently
17738 masked to only allow access from the scheduler user (typically root).
17739 This is done because printer device URIs sometimes contain sensitive
17740 authentication information that should not be generally known on the
17741 system. There is no way to disable this security feature.
17743 Defaults to @samp{"0640"}.
17746 @deftypevr {@code{files-configuration} parameter} log-location error-log
17747 Defines the error log filename. Specifying a blank filename disables
17748 error log generation. The value @code{stderr} causes log entries to be
17749 sent to the standard error file when the scheduler is running in the
17750 foreground, or to the system log daemon when run in the background. The
17751 value @code{syslog} causes log entries to be sent to the system log
17752 daemon. The server name may be included in filenames using the string
17753 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
17755 Defaults to @samp{"/var/log/cups/error_log"}.
17758 @deftypevr {@code{files-configuration} parameter} string fatal-errors
17759 Specifies which errors are fatal, causing the scheduler to exit. The
17764 No errors are fatal.
17767 All of the errors below are fatal.
17770 Browsing initialization errors are fatal, for example failed connections
17771 to the DNS-SD daemon.
17774 Configuration file syntax errors are fatal.
17777 Listen or Port errors are fatal, except for IPv6 failures on the
17778 loopback or @code{any} addresses.
17781 Log file creation or write errors are fatal.
17784 Bad startup file permissions are fatal, for example shared TLS
17785 certificate and key files with world-read permissions.
17788 Defaults to @samp{"all -browse"}.
17791 @deftypevr {@code{files-configuration} parameter} boolean file-device?
17792 Specifies whether the file pseudo-device can be used for new printer
17793 queues. The URI @uref{file:///dev/null} is always allowed.
17795 Defaults to @samp{#f}.
17798 @deftypevr {@code{files-configuration} parameter} string group
17799 Specifies the group name or ID that will be used when executing external
17802 Defaults to @samp{"lp"}.
17805 @deftypevr {@code{files-configuration} parameter} string log-file-perm
17806 Specifies the permissions for all log files that the scheduler writes.
17808 Defaults to @samp{"0644"}.
17811 @deftypevr {@code{files-configuration} parameter} log-location page-log
17812 Defines the page log filename. Specifying a blank filename disables
17813 page log generation. The value @code{stderr} causes log entries to be
17814 sent to the standard error file when the scheduler is running in the
17815 foreground, or to the system log daemon when run in the background. The
17816 value @code{syslog} causes log entries to be sent to the system log
17817 daemon. The server name may be included in filenames using the string
17818 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
17820 Defaults to @samp{"/var/log/cups/page_log"}.
17823 @deftypevr {@code{files-configuration} parameter} string remote-root
17824 Specifies the username that is associated with unauthenticated accesses
17825 by clients claiming to be the root user. The default is @code{remroot}.
17827 Defaults to @samp{"remroot"}.
17830 @deftypevr {@code{files-configuration} parameter} file-name request-root
17831 Specifies the directory that contains print jobs and other HTTP request
17834 Defaults to @samp{"/var/spool/cups"}.
17837 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
17838 Specifies the level of security sandboxing that is applied to print
17839 filters, backends, and other child processes of the scheduler; either
17840 @code{relaxed} or @code{strict}. This directive is currently only
17841 used/supported on macOS.
17843 Defaults to @samp{strict}.
17846 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
17847 Specifies the location of TLS certificates and private keys. CUPS will
17848 look for public and private keys in this directory: @file{.crt} files
17849 for PEM-encoded certificates and corresponding @file{.key} files for
17850 PEM-encoded private keys.
17852 Defaults to @samp{"/etc/cups/ssl"}.
17855 @deftypevr {@code{files-configuration} parameter} file-name server-root
17856 Specifies the directory containing the server configuration files.
17858 Defaults to @samp{"/etc/cups"}.
17861 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
17862 Specifies whether the scheduler calls fsync(2) after writing
17863 configuration or state files.
17865 Defaults to @samp{#f}.
17868 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
17869 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
17872 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
17873 Specifies the directory where temporary files are stored.
17875 Defaults to @samp{"/var/spool/cups/tmp"}.
17878 @deftypevr {@code{files-configuration} parameter} string user
17879 Specifies the user name or ID that is used when running external
17882 Defaults to @samp{"lp"}.
17885 @deftypevr {@code{files-configuration} parameter} string set-env
17886 Set the specified environment variable to be passed to child processes.
17888 Defaults to @samp{"variable value"}.
17892 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
17893 Specifies the logging level for the AccessLog file. The @code{config}
17894 level logs when printers and classes are added, deleted, or modified and
17895 when configuration files are accessed or updated. The @code{actions}
17896 level logs when print jobs are submitted, held, released, modified, or
17897 canceled, and any of the conditions for @code{config}. The @code{all}
17898 level logs all requests.
17900 Defaults to @samp{actions}.
17903 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
17904 Specifies whether to purge job history data automatically when it is no
17905 longer required for quotas.
17907 Defaults to @samp{#f}.
17910 @deftypevr {@code{cups-configuration} parameter} comma-separated-string-list browse-dns-sd-sub-types
17911 Specifies a list of DNS-SD sub-types to advertise for each shared printer.
17912 For example, @samp{"_cups" "_print"} will tell network clients that both
17913 CUPS sharing and IPP Everywhere are supported.
17915 Defaults to @samp{"_cups"}.
17918 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
17919 Specifies which protocols to use for local printer sharing.
17921 Defaults to @samp{dnssd}.
17924 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
17925 Specifies whether the CUPS web interface is advertised.
17927 Defaults to @samp{#f}.
17930 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
17931 Specifies whether shared printers are advertised.
17933 Defaults to @samp{#f}.
17936 @deftypevr {@code{cups-configuration} parameter} string classification
17937 Specifies the security classification of the server. Any valid banner
17938 name can be used, including @samp{"classified"}, @samp{"confidential"},
17939 @samp{"secret"}, @samp{"topsecret"}, and @samp{"unclassified"}, or the
17940 banner can be omitted to disable secure printing functions.
17942 Defaults to @samp{""}.
17945 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
17946 Specifies whether users may override the classification (cover page) of
17947 individual print jobs using the @code{job-sheets} option.
17949 Defaults to @samp{#f}.
17952 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
17953 Specifies the default type of authentication to use.
17955 Defaults to @samp{Basic}.
17958 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
17959 Specifies whether encryption will be used for authenticated requests.
17961 Defaults to @samp{Required}.
17964 @deftypevr {@code{cups-configuration} parameter} string default-language
17965 Specifies the default language to use for text and web content.
17967 Defaults to @samp{"en"}.
17970 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
17971 Specifies the default paper size for new print queues. @samp{"Auto"}
17972 uses a locale-specific default, while @samp{"None"} specifies there is
17973 no default paper size. Specific size names are typically
17974 @samp{"Letter"} or @samp{"A4"}.
17976 Defaults to @samp{"Auto"}.
17979 @deftypevr {@code{cups-configuration} parameter} string default-policy
17980 Specifies the default access policy to use.
17982 Defaults to @samp{"default"}.
17985 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
17986 Specifies whether local printers are shared by default.
17988 Defaults to @samp{#t}.
17991 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
17992 Specifies the delay for updating of configuration and state files, in
17993 seconds. A value of 0 causes the update to happen as soon as possible,
17994 typically within a few milliseconds.
17996 Defaults to @samp{30}.
17999 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
18000 Specifies what to do when an error occurs. Possible values are
18001 @code{abort-job}, which will discard the failed print job;
18002 @code{retry-job}, which will retry the job at a later time;
18003 @code{retry-current-job}, which retries the failed job immediately; and
18004 @code{stop-printer}, which stops the printer.
18006 Defaults to @samp{stop-printer}.
18009 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
18010 Specifies the maximum cost of filters that are run concurrently, which
18011 can be used to minimize disk, memory, and CPU resource problems. A
18012 limit of 0 disables filter limiting. An average print to a
18013 non-PostScript printer needs a filter limit of about 200. A PostScript
18014 printer needs about half that (100). Setting the limit below these
18015 thresholds will effectively limit the scheduler to printing a single job
18018 Defaults to @samp{0}.
18021 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
18022 Specifies the scheduling priority of filters that are run to print a
18023 job. The nice value ranges from 0, the highest priority, to 19, the
18026 Defaults to @samp{0}.
18029 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
18030 Specifies whether to do reverse lookups on connecting clients. The
18031 @code{double} setting causes @code{cupsd} to verify that the hostname
18032 resolved from the address matches one of the addresses returned for that
18033 hostname. Double lookups also prevent clients with unregistered
18034 addresses from connecting to your server. Only set this option to
18035 @code{#t} or @code{double} if absolutely required.
18037 Defaults to @samp{#f}.
18040 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
18041 Specifies the number of seconds to wait before killing the filters and
18042 backend associated with a canceled or held job.
18044 Defaults to @samp{30}.
18047 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
18048 Specifies the interval between retries of jobs in seconds. This is
18049 typically used for fax queues but can also be used with normal print
18050 queues whose error policy is @code{retry-job} or
18051 @code{retry-current-job}.
18053 Defaults to @samp{30}.
18056 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
18057 Specifies the number of retries that are done for jobs. This is
18058 typically used for fax queues but can also be used with normal print
18059 queues whose error policy is @code{retry-job} or
18060 @code{retry-current-job}.
18062 Defaults to @samp{5}.
18065 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
18066 Specifies whether to support HTTP keep-alive connections.
18068 Defaults to @samp{#t}.
18071 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
18072 Specifies how long an idle client connection remains open, in seconds.
18074 Defaults to @samp{30}.
18077 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
18078 Specifies the maximum size of print files, IPP requests, and HTML form
18079 data. A limit of 0 disables the limit check.
18081 Defaults to @samp{0}.
18084 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
18085 Listens on the specified interfaces for connections. Valid values are
18086 of the form @var{address}:@var{port}, where @var{address} is either an
18087 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
18088 indicate all addresses. Values can also be file names of local UNIX
18089 domain sockets. The Listen directive is similar to the Port directive
18090 but allows you to restrict access to specific interfaces or networks.
18093 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
18094 Specifies the number of pending connections that will be allowed. This
18095 normally only affects very busy servers that have reached the MaxClients
18096 limit, but can also be triggered by large numbers of simultaneous
18097 connections. When the limit is reached, the operating system will
18098 refuse additional connections until the scheduler can accept the pending
18101 Defaults to @samp{128}.
18104 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
18105 Specifies a set of additional access controls.
18107 Available @code{location-access-controls} fields are:
18109 @deftypevr {@code{location-access-controls} parameter} file-name path
18110 Specifies the URI path to which the access control applies.
18113 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
18114 Access controls for all access to this path, in the same format as the
18115 @code{access-controls} of @code{operation-access-control}.
18117 Defaults to @samp{()}.
18120 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
18121 Access controls for method-specific access to this path.
18123 Defaults to @samp{()}.
18125 Available @code{method-access-controls} fields are:
18127 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
18128 If @code{#t}, apply access controls to all methods except the listed
18129 methods. Otherwise apply to only the listed methods.
18131 Defaults to @samp{#f}.
18134 @deftypevr {@code{method-access-controls} parameter} method-list methods
18135 Methods to which this access control applies.
18137 Defaults to @samp{()}.
18140 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
18141 Access control directives, as a list of strings. Each string should be
18142 one directive, such as @samp{"Order allow,deny"}.
18144 Defaults to @samp{()}.
18149 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
18150 Specifies the number of debugging messages that are retained for logging
18151 if an error occurs in a print job. Debug messages are logged regardless
18152 of the LogLevel setting.
18154 Defaults to @samp{100}.
18157 @deftypevr {@code{cups-configuration} parameter} log-level log-level
18158 Specifies the level of logging for the ErrorLog file. The value
18159 @code{none} stops all logging while @code{debug2} logs everything.
18161 Defaults to @samp{info}.
18164 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
18165 Specifies the format of the date and time in the log files. The value
18166 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
18168 Defaults to @samp{standard}.
18171 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
18172 Specifies the maximum number of simultaneous clients that are allowed by
18175 Defaults to @samp{100}.
18178 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
18179 Specifies the maximum number of simultaneous clients that are allowed
18180 from a single address.
18182 Defaults to @samp{100}.
18185 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
18186 Specifies the maximum number of copies that a user can print of each
18189 Defaults to @samp{9999}.
18192 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
18193 Specifies the maximum time a job may remain in the @code{indefinite}
18194 hold state before it is canceled. A value of 0 disables cancellation of
18197 Defaults to @samp{0}.
18200 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
18201 Specifies the maximum number of simultaneous jobs that are allowed. Set
18202 to 0 to allow an unlimited number of jobs.
18204 Defaults to @samp{500}.
18207 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
18208 Specifies the maximum number of simultaneous jobs that are allowed per
18209 printer. A value of 0 allows up to MaxJobs jobs per printer.
18211 Defaults to @samp{0}.
18214 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
18215 Specifies the maximum number of simultaneous jobs that are allowed per
18216 user. A value of 0 allows up to MaxJobs jobs per user.
18218 Defaults to @samp{0}.
18221 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
18222 Specifies the maximum time a job may take to print before it is
18223 canceled, in seconds. Set to 0 to disable cancellation of ``stuck'' jobs.
18225 Defaults to @samp{10800}.
18228 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
18229 Specifies the maximum size of the log files before they are rotated, in
18230 bytes. The value 0 disables log rotation.
18232 Defaults to @samp{1048576}.
18235 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
18236 Specifies the maximum amount of time to allow between files in a
18237 multiple file print job, in seconds.
18239 Defaults to @samp{300}.
18242 @deftypevr {@code{cups-configuration} parameter} string page-log-format
18243 Specifies the format of PageLog lines. Sequences beginning with percent
18244 (@samp{%}) characters are replaced with the corresponding information,
18245 while all other characters are copied literally. The following percent
18246 sequences are recognized:
18250 insert a single percent character
18253 insert the value of the specified IPP attribute
18256 insert the number of copies for the current page
18259 insert the current page number
18262 insert the current date and time in common log format
18268 insert the printer name
18271 insert the username
18274 A value of the empty string disables page logging. The string @code{%p
18275 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
18276 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
18279 Defaults to @samp{""}.
18282 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
18283 Passes the specified environment variable(s) to child processes; a list
18286 Defaults to @samp{()}.
18289 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
18290 Specifies named access control policies.
18292 Available @code{policy-configuration} fields are:
18294 @deftypevr {@code{policy-configuration} parameter} string name
18295 Name of the policy.
18298 @deftypevr {@code{policy-configuration} parameter} string job-private-access
18299 Specifies an access list for a job's private values. @code{@@ACL} maps
18300 to the printer's requesting-user-name-allowed or
18301 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
18302 owner. @code{@@SYSTEM} maps to the groups listed for the
18303 @code{system-group} field of the @code{files-config} configuration,
18304 which is reified into the @code{cups-files.conf(5)} file. Other
18305 possible elements of the access list include specific user names, and
18306 @code{@@@var{group}} to indicate members of a specific group. The
18307 access list may also be simply @code{all} or @code{default}.
18309 Defaults to @samp{"@@OWNER @@SYSTEM"}.
18312 @deftypevr {@code{policy-configuration} parameter} string job-private-values
18313 Specifies the list of job values to make private, or @code{all},
18314 @code{default}, or @code{none}.
18316 Defaults to @samp{"job-name job-originating-host-name
18317 job-originating-user-name phone"}.
18320 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
18321 Specifies an access list for a subscription's private values.
18322 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
18323 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
18324 owner. @code{@@SYSTEM} maps to the groups listed for the
18325 @code{system-group} field of the @code{files-config} configuration,
18326 which is reified into the @code{cups-files.conf(5)} file. Other
18327 possible elements of the access list include specific user names, and
18328 @code{@@@var{group}} to indicate members of a specific group. The
18329 access list may also be simply @code{all} or @code{default}.
18331 Defaults to @samp{"@@OWNER @@SYSTEM"}.
18334 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
18335 Specifies the list of job values to make private, or @code{all},
18336 @code{default}, or @code{none}.
18338 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
18339 notify-subscriber-user-name notify-user-data"}.
18342 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
18343 Access control by IPP operation.
18345 Defaults to @samp{()}.
18349 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
18350 Specifies whether job files (documents) are preserved after a job is
18351 printed. If a numeric value is specified, job files are preserved for
18352 the indicated number of seconds after printing. Otherwise a boolean
18353 value applies indefinitely.
18355 Defaults to @samp{86400}.
18358 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
18359 Specifies whether the job history is preserved after a job is printed.
18360 If a numeric value is specified, the job history is preserved for the
18361 indicated number of seconds after printing. If @code{#t}, the job
18362 history is preserved until the MaxJobs limit is reached.
18364 Defaults to @samp{#t}.
18367 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
18368 Specifies the amount of time to wait for job completion before
18369 restarting the scheduler.
18371 Defaults to @samp{30}.
18374 @deftypevr {@code{cups-configuration} parameter} string rip-cache
18375 Specifies the maximum amount of memory to use when converting documents
18376 into bitmaps for a printer.
18378 Defaults to @samp{"128m"}.
18381 @deftypevr {@code{cups-configuration} parameter} string server-admin
18382 Specifies the email address of the server administrator.
18384 Defaults to @samp{"root@@localhost.localdomain"}.
18387 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
18388 The ServerAlias directive is used for HTTP Host header validation when
18389 clients connect to the scheduler from external interfaces. Using the
18390 special name @code{*} can expose your system to known browser-based DNS
18391 rebinding attacks, even when accessing sites through a firewall. If the
18392 auto-discovery of alternate names does not work, we recommend listing
18393 each alternate name with a ServerAlias directive instead of using
18396 Defaults to @samp{*}.
18399 @deftypevr {@code{cups-configuration} parameter} string server-name
18400 Specifies the fully-qualified host name of the server.
18402 Defaults to @samp{"localhost"}.
18405 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
18406 Specifies what information is included in the Server header of HTTP
18407 responses. @code{None} disables the Server header. @code{ProductOnly}
18408 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
18409 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
18410 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
18411 the output of the @code{uname} command. @code{Full} reports @code{CUPS
18412 2.0.0 (@var{uname}) IPP/2.0}.
18414 Defaults to @samp{Minimal}.
18417 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
18418 Listens on the specified interfaces for encrypted connections. Valid
18419 values are of the form @var{address}:@var{port}, where @var{address} is
18420 either an IPv6 address enclosed in brackets, an IPv4 address, or
18421 @code{*} to indicate all addresses.
18423 Defaults to @samp{()}.
18426 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
18427 Sets encryption options. By default, CUPS only supports encryption
18428 using TLS v1.0 or higher using known secure cipher suites. Security is
18429 reduced when @code{Allow} options are used, and enhanced when @code{Deny}
18430 options are used. The @code{AllowRC4} option enables the 128-bit RC4 cipher
18431 suites, which are required for some older clients. The @code{AllowSSL3} option
18432 enables SSL v3.0, which is required for some older clients that do not support
18433 TLS v1.0. The @code{DenyCBC} option disables all CBC cipher suites. The
18434 @code{DenyTLS1.0} option disables TLS v1.0 support - this sets the minimum
18435 protocol version to TLS v1.1.
18437 Defaults to @samp{()}.
18440 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
18441 Specifies whether the scheduler requires clients to strictly adhere to
18442 the IPP specifications.
18444 Defaults to @samp{#f}.
18447 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
18448 Specifies the HTTP request timeout, in seconds.
18450 Defaults to @samp{300}.
18454 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
18455 Specifies whether the web interface is enabled.
18457 Defaults to @samp{#f}.
18460 At this point you're probably thinking ``oh dear, Guix manual, I like
18461 you but you can stop already with the configuration options''. Indeed.
18462 However, one more point: it could be that you have an existing
18463 @code{cupsd.conf} that you want to use. In that case, you can pass an
18464 @code{opaque-cups-configuration} as the configuration of a
18465 @code{cups-service-type}.
18467 Available @code{opaque-cups-configuration} fields are:
18469 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
18473 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
18474 The contents of the @code{cupsd.conf}, as a string.
18477 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
18478 The contents of the @code{cups-files.conf} file, as a string.
18481 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
18482 strings of the same name, you could instantiate a CUPS service like
18486 (service cups-service-type
18487 (opaque-cups-configuration
18488 (cupsd.conf cupsd.conf)
18489 (cups-files.conf cups-files.conf)))
18493 @node Desktop Services
18494 @subsection Desktop Services
18496 The @code{(gnu services desktop)} module provides services that are
18497 usually useful in the context of a ``desktop'' setup---that is, on a
18498 machine running a graphical display server, possibly with graphical user
18499 interfaces, etc. It also defines services that provide specific desktop
18500 environments like GNOME, Xfce or MATE.
18502 To simplify things, the module defines a variable containing the set of
18503 services that users typically expect on a machine with a graphical
18504 environment and networking:
18506 @defvr {Scheme Variable} %desktop-services
18507 This is a list of services that builds upon @code{%base-services} and
18508 adds or adjusts services for a typical ``desktop'' setup.
18510 In particular, it adds a graphical login manager (@pxref{X Window,
18511 @code{gdm-service-type}}), screen lockers, a network management tool
18512 (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
18513 support (@pxref{Networking Services, @code{modem-manager-service-type}}),
18514 energy and color management services, the @code{elogind} login and seat
18515 manager, the Polkit privilege service, the GeoClue location service, the
18516 AccountsService daemon that allows authorized users change system passwords,
18517 an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
18518 name service switch service configured to be able to use @code{nss-mdns}
18519 (@pxref{Name Service Switch, mDNS}).
18522 The @code{%desktop-services} variable can be used as the @code{services}
18523 field of an @code{operating-system} declaration (@pxref{operating-system
18524 Reference, @code{services}}).
18526 Additionally, the @code{gnome-desktop-service-type},
18527 @code{xfce-desktop-service}, @code{mate-desktop-service-type},
18528 @code{lxqt-desktop-service-type} and @code{enlightenment-desktop-service-type}
18529 procedures can add GNOME, Xfce, MATE and/or Enlightenment to a system. To
18530 ``add GNOME'' means that system-level services like the backlight adjustment
18531 helpers and the power management utilities are added to the system, extending
18532 @code{polkit} and @code{dbus} appropriately, allowing GNOME to operate with
18533 elevated privileges on a limited number of special-purpose system interfaces.
18534 Additionally, adding a service made by @code{gnome-desktop-service-type} adds
18535 the GNOME metapackage to the system profile. Likewise, adding the Xfce
18536 service not only adds the @code{xfce} metapackage to the system profile, but
18537 it also gives the Thunar file manager the ability to open a ``root-mode'' file
18538 management window, if the user authenticates using the administrator's
18539 password via the standard polkit graphical interface. To ``add MATE'' means
18540 that @code{polkit} and @code{dbus} are extended appropriately, allowing MATE
18541 to operate with elevated privileges on a limited number of special-purpose
18542 system interfaces. Additionally, adding a service of type
18543 @code{mate-desktop-service-type} adds the MATE metapackage to the system
18544 profile. ``Adding Enlightenment'' means that @code{dbus} is extended
18545 appropriately, and several of Enlightenment's binaries are set as setuid,
18546 allowing Enlightenment's screen locker and other functionality to work as
18549 The desktop environments in Guix use the Xorg display server by
18550 default. If you'd like to use the newer display server protocol
18551 called Wayland, you need to use the @code{sddm-service} instead of
18552 GDM as the graphical login manager. You should then
18553 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
18554 also try starting GNOME on Wayland manually from a TTY with the
18555 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
18556 gnome-session``. Currently only GNOME has support for Wayland.
18558 @defvr {Scheme Variable} gnome-desktop-service-type
18559 This is the type of the service that adds the @uref{https://www.gnome.org,
18560 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
18561 object (see below).
18563 This service adds the @code{gnome} package to the system profile, and extends
18564 polkit with the actions from @code{gnome-settings-daemon}.
18567 @deftp {Data Type} gnome-desktop-configuration
18568 Configuration record for the GNOME desktop environment.
18571 @item @code{gnome} (default: @code{gnome})
18572 The GNOME package to use.
18576 @defvr {Scheme Variable} xfce-desktop-service-type
18577 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
18578 desktop environment. Its value is an @code{xfce-desktop-configuration} object
18581 This service adds the @code{xfce} package to the system profile, and
18582 extends polkit with the ability for @code{thunar} to manipulate the file
18583 system as root from within a user session, after the user has authenticated
18584 with the administrator's password.
18586 Note that @code{xfce4-panel} and its plugin packages should be installed in
18587 the same profile to ensure compatibility. When using this service, you should
18588 add extra plugins (@code{xfce4-whiskermenu-plugin},
18589 @code{xfce4-weather-plugin}, etc.) to the @code{packages} field of your
18590 @code{operating-system}.
18593 @deftp {Data Type} xfce-desktop-configuration
18594 Configuration record for the Xfce desktop environment.
18597 @item @code{xfce} (default: @code{xfce})
18598 The Xfce package to use.
18602 @deffn {Scheme Variable} mate-desktop-service-type
18603 This is the type of the service that runs the @uref{https://mate-desktop.org/,
18604 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
18605 object (see below).
18607 This service adds the @code{mate} package to the system
18608 profile, and extends polkit with the actions from
18609 @code{mate-settings-daemon}.
18612 @deftp {Data Type} mate-desktop-configuration
18613 Configuration record for the MATE desktop environment.
18616 @item @code{mate} (default: @code{mate})
18617 The MATE package to use.
18621 @deffn {Scheme Variable} lxqt-desktop-service-type
18622 This is the type of the service that runs the @uref{https://lxqt.github.io,
18623 LXQt desktop environment}. Its value is a @code{lxqt-desktop-configuration}
18624 object (see below).
18626 This service adds the @code{lxqt} package to the system
18630 @deftp {Data Type} lxqt-desktop-configuration
18631 Configuration record for the LXQt desktop environment.
18634 @item @code{lxqt} (default: @code{lxqt})
18635 The LXQT package to use.
18639 @deffn {Scheme Variable} enlightenment-desktop-service-type
18640 Return a service that adds the @code{enlightenment} package to the system
18641 profile, and extends dbus with actions from @code{efl}.
18644 @deftp {Data Type} enlightenment-desktop-service-configuration
18646 @item @code{enlightenment} (default: @code{enlightenment})
18647 The enlightenment package to use.
18651 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
18652 the default @code{%desktop-services} variable doesn't include any of
18653 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
18654 @code{%desktop-services} in the @code{services} field of your
18655 @code{operating-system}:
18658 (use-modules (gnu))
18659 (use-service-modules desktop)
18662 ;; cons* adds items to the list given as its last argument.
18663 (services (cons* (service gnome-desktop-service-type)
18664 (service xfce-desktop-service)
18665 %desktop-services))
18669 These desktop environments will then be available as options in the
18670 graphical login window.
18672 The actual service definitions included in @code{%desktop-services} and
18673 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
18674 are described below.
18676 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
18677 Return a service that runs the ``system bus'', using @var{dbus}, with
18678 support for @var{services}.
18680 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
18681 facility. Its system bus is used to allow system services to communicate
18682 and to be notified of system-wide events.
18684 @var{services} must be a list of packages that provide an
18685 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
18686 and policy files. For example, to allow avahi-daemon to use the system bus,
18687 @var{services} must be equal to @code{(list avahi)}.
18690 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
18691 Return a service that runs the @code{elogind} login and
18692 seat management daemon. @uref{https://github.com/elogind/elogind,
18693 Elogind} exposes a D-Bus interface that can be used to know which users
18694 are logged in, know what kind of sessions they have open, suspend the
18695 system, inhibit system suspend, reboot the system, and other tasks.
18697 Elogind handles most system-level power events for a computer, for
18698 example suspending the system when a lid is closed, or shutting it down
18699 when the power button is pressed.
18701 The @var{config} keyword argument specifies the configuration for
18702 elogind, and should be the result of an @code{(elogind-configuration
18703 (@var{parameter} @var{value})...)} invocation. Available parameters and
18704 their default values are:
18707 @item kill-user-processes?
18709 @item kill-only-users
18711 @item kill-exclude-users
18713 @item inhibit-delay-max-seconds
18715 @item handle-power-key
18717 @item handle-suspend-key
18719 @item handle-hibernate-key
18721 @item handle-lid-switch
18723 @item handle-lid-switch-docked
18725 @item handle-lid-switch-external-power
18727 @item power-key-ignore-inhibited?
18729 @item suspend-key-ignore-inhibited?
18731 @item hibernate-key-ignore-inhibited?
18733 @item lid-switch-ignore-inhibited?
18735 @item holdoff-timeout-seconds
18739 @item idle-action-seconds
18741 @item runtime-directory-size-percent
18743 @item runtime-directory-size
18747 @item suspend-state
18748 @code{("mem" "standby" "freeze")}
18751 @item hibernate-state
18753 @item hibernate-mode
18754 @code{("platform" "shutdown")}
18755 @item hybrid-sleep-state
18757 @item hybrid-sleep-mode
18758 @code{("suspend" "platform" "shutdown")}
18762 @deffn {Scheme Procedure} accountsservice-service @
18763 [#:accountsservice @var{accountsservice}]
18764 Return a service that runs AccountsService, a system service that can
18765 list available accounts, change their passwords, and so on.
18766 AccountsService integrates with PolicyKit to enable unprivileged users
18767 to acquire the capability to modify their system configuration.
18768 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
18769 accountsservice web site} for more information.
18771 The @var{accountsservice} keyword argument is the @code{accountsservice}
18772 package to expose as a service.
18775 @deffn {Scheme Procedure} polkit-service @
18776 [#:polkit @var{polkit}]
18777 Return a service that runs the
18778 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
18779 management service}, which allows system administrators to grant access to
18780 privileged operations in a structured way. By querying the Polkit service, a
18781 privileged system component can know when it should grant additional
18782 capabilities to ordinary users. For example, an ordinary user can be granted
18783 the capability to suspend the system if the user is logged in locally.
18786 @defvr {Scheme Variable} polkit-wheel-service
18787 Service that adds the @code{wheel} group as admins to the Polkit
18788 service. This makes it so that users in the @code{wheel} group are queried
18789 for their own passwords when performing administrative actions instead of
18790 @code{root}'s, similar to the behaviour used by @code{sudo}.
18793 @defvr {Scheme Variable} upower-service-type
18794 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
18795 system-wide monitor for power consumption and battery levels, with the given
18796 configuration settings.
18798 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
18799 notably used by GNOME.
18802 @deftp {Data Type} upower-configuration
18803 Data type representation the configuration for UPower.
18807 @item @code{upower} (default: @var{upower})
18808 Package to use for @code{upower}.
18810 @item @code{watts-up-pro?} (default: @code{#f})
18811 Enable the Watts Up Pro device.
18813 @item @code{poll-batteries?} (default: @code{#t})
18814 Enable polling the kernel for battery level changes.
18816 @item @code{ignore-lid?} (default: @code{#f})
18817 Ignore the lid state, this can be useful if it's incorrect on a device.
18819 @item @code{use-percentage-for-policy?} (default: @code{#f})
18820 Whether battery percentage based policy should be used. The default is to use
18821 the time left, change to @code{#t} to use the percentage.
18823 @item @code{percentage-low} (default: @code{10})
18824 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
18825 at which the battery is considered low.
18827 @item @code{percentage-critical} (default: @code{3})
18828 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
18829 at which the battery is considered critical.
18831 @item @code{percentage-action} (default: @code{2})
18832 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
18833 at which action will be taken.
18835 @item @code{time-low} (default: @code{1200})
18836 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
18837 seconds at which the battery is considered low.
18839 @item @code{time-critical} (default: @code{300})
18840 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
18841 seconds at which the battery is considered critical.
18843 @item @code{time-action} (default: @code{120})
18844 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
18845 seconds at which action will be taken.
18847 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
18848 The action taken when @code{percentage-action} or @code{time-action} is
18849 reached (depending on the configuration of @code{use-percentage-for-policy?}).
18851 Possible values are:
18861 @code{'hybrid-sleep}.
18867 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
18868 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
18869 UDisks}, a @dfn{disk management} daemon that provides user interfaces
18870 with notifications and ways to mount/unmount disks. Programs that talk
18871 to UDisks include the @command{udisksctl} command, part of UDisks, and
18872 GNOME Disks. Note that Udisks relies on the @command{mount} command, so
18873 it will only be able to use the file-system utilities installed in the
18874 system profile. For example if you want to be able to mount NTFS
18875 file-systems in read and write fashion, you'll need to have
18876 @code{ntfs-3g} installed system-wide.
18879 @deffn {Scheme Variable} colord-service-type
18880 This is the type of the service that runs @command{colord}, a system
18881 service with a D-Bus
18882 interface to manage the color profiles of input and output devices such as
18883 screens and scanners. It is notably used by the GNOME Color Manager graphical
18884 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
18885 site} for more information.
18888 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
18889 Return a configuration allowing an application to access GeoClue
18890 location data. @var{name} is the Desktop ID of the application, without
18891 the @code{.desktop} part. If @var{allowed?} is true, the application
18892 will have access to location information by default. The boolean
18893 @var{system?} value indicates whether an application is a system component
18894 or not. Finally @var{users} is a list of UIDs of all users for which
18895 this application is allowed location info access. An empty users list
18896 means that all users are allowed.
18899 @cindex scanner access
18900 @deffn {Scheme Procedure} sane-service-type
18901 This service provides access to scanners @i{via}
18902 @uref{http://www.sane-project.org, SANE} by installing the necessary udev
18906 @defvr {Scheme Variable} %standard-geoclue-applications
18907 The standard list of well-known GeoClue application configurations,
18908 granting authority to the GNOME date-and-time utility to ask for the
18909 current location in order to set the time zone, and allowing the
18910 IceCat and Epiphany web browsers to request location information.
18911 IceCat and Epiphany both query the user before allowing a web page to
18912 know the user's location.
18915 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
18916 [#:whitelist '()] @
18917 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
18918 [#:submit-data? #f]
18919 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
18920 [#:submission-nick "geoclue"] @
18921 [#:applications %standard-geoclue-applications]
18922 Return a service that runs the GeoClue location service. This service
18923 provides a D-Bus interface to allow applications to request access to a
18924 user's physical location, and optionally to add information to online
18925 location databases. See
18926 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
18927 web site} for more information.
18930 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
18931 [@w{#:auto-enable? #f}]
18932 Return a service that runs the @command{bluetoothd} daemon, which
18933 manages all the Bluetooth devices and provides a number of D-Bus
18934 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
18935 powered automatically at boot, which can be useful when using a
18936 bluetooth keyboard or mouse.
18938 Users need to be in the @code{lp} group to access the D-Bus service.
18941 @defvr {Scheme Variable} gnome-keyring-service-type
18942 This is the type of the service that adds the
18943 @uref{https://wiki.gnome.org/Projects/GnomeKeyring, GNOME Keyring}. Its
18944 value is a @code{gnome-keyring-configuration} object (see below).
18946 This service adds the @code{gnome-keyring} package to the system profile
18947 and extends PAM with entries using @code{pam_gnome_keyring.so}, unlocking
18948 a user's login keyring when they log in or setting its password with passwd.
18951 @deftp {Data Type} gnome-keyring-configuration
18952 Configuration record for the GNOME Keyring service.
18955 @item @code{keyring} (default: @code{gnome-keyring})
18956 The GNOME keyring package to use.
18958 @item @code{pam-services}
18959 A list of @code{(@var{service} . @var{kind})} pairs denoting PAM
18960 services to extend, where @var{service} is the name of an existing
18961 service to extend and @var{kind} is one of @code{login} or
18964 If @code{login} is given, it adds an optional
18965 @code{pam_gnome_keyring.so} to the auth block without arguments and to
18966 the session block with @code{auto_start}. If @code{passwd} is given, it
18967 adds an optional @code{pam_gnome_keyring.so} to the password block
18970 By default, this field contains ``gdm-password'' with the value @code{login}
18971 and ``passwd'' is with the value @code{passwd}.
18976 @node Sound Services
18977 @subsection Sound Services
18979 @cindex sound support
18981 @cindex PulseAudio, sound support
18983 The @code{(gnu services sound)} module provides a service to configure the
18984 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
18985 preferred ALSA output driver.
18987 @deffn {Scheme Variable} alsa-service-type
18988 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
18989 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
18990 configuration file. The value for this type is a @command{alsa-configuration}
18991 record as in this example:
18994 (service alsa-service-type)
18997 See below for details about @code{alsa-configuration}.
19000 @deftp {Data Type} alsa-configuration
19001 Data type representing the configuration for @code{alsa-service}.
19004 @item @code{alsa-plugins} (default: @var{alsa-plugins})
19005 @code{alsa-plugins} package to use.
19007 @item @code{pulseaudio?} (default: @var{#t})
19008 Whether ALSA applications should transparently be made to use the
19009 @uref{https://www.pulseaudio.org/, PulseAudio} sound server.
19011 Using PulseAudio allows you to run several sound-producing applications
19012 at the same time and to individual control them @i{via}
19013 @command{pavucontrol}, among other things.
19015 @item @code{extra-options} (default: @var{""})
19016 String to append to the @file{/etc/asound.conf} file.
19021 Individual users who want to override the system configuration of ALSA can do
19022 it with the @file{~/.asoundrc} file:
19025 # In guix, we have to specify the absolute path for plugins.
19027 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
19030 # Routing ALSA to jack:
19031 # <http://jackaudio.org/faq/routing_alsa.html>.
19035 0 system:playback_1
19036 1 system:playback_2
19053 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
19056 @deffn {Scheme Variable} pulseaudio-service-type
19057 This is the type for the @uref{https://www.pulseaudio.org/, PulseAudio}
19058 sound server. It exists to allow system overrides of the default settings
19059 via @code{pulseaudio-configuration}, see below.
19062 This service overrides per-user configuration files. If you want
19063 PulseAudio to honor configuration files in @file{~/.config/pulse} you
19064 have to unset the environment variables @env{PULSE_CONFIG} and
19065 @env{PULSE_CLIENTCONFIG} in your @file{~/.bash_profile}.
19069 This service on its own does not ensure, that the @code{pulseaudio} package
19070 exists on your machine. It merely adds configuration files for it, as
19071 detailed below. In the (admittedly unlikely) case, that you find yourself
19072 without a @code{pulseaudio} package, consider enabling it through the
19073 @code{alsa-service-type} above.
19077 @deftp {Data Type} pulseaudio-configuration
19078 Data type representing the configuration for @code{pulseaudio-service}.
19081 @item @code{client-conf} (default: @code{'()})
19082 List of settings to set in @file{client.conf}.
19083 Accepts a list of strings or a symbol-value pairs. A string will be
19084 inserted as-is with a newline added. A pair will be formatted as
19085 ``key = value'', again with a newline added.
19087 @item @code{daemon-conf} (default: @code{'((flat-volumes . no))})
19088 List of settings to set in @file{daemon.conf}, formatted just like
19091 @item @code{script-file} (default: @code{(file-append pulseaudio "/etc/pulse/default.pa")})
19092 Script file to use as @file{default.pa}.
19094 @item @code{system-script-file} (default: @code{(file-append pulseaudio "/etc/pulse/system.pa")})
19095 Script file to use as @file{system.pa}.
19099 @deffn {Scheme Variable} ladspa-service-type
19100 This service sets the @var{LADSPA_PATH} variable, so that programs, which
19101 respect it, e.g. PulseAudio, can load LADSPA plugins.
19103 The following example will setup the service to enable modules from the
19104 @code{swh-plugins} package:
19107 (service ladspa-service-type
19108 (ladspa-configuration (plugins (list swh-plugins))))
19111 See @uref{http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html} for the
19116 @node Database Services
19117 @subsection Database Services
19121 The @code{(gnu services databases)} module provides the following services.
19123 @subsubheading PostgreSQL
19125 The following example describes a PostgreSQL service with the default
19129 (service postgresql-service-type
19130 (postgresql-configuration
19131 (postgresql postgresql-10)))
19134 If the services fails to start, it may be due to an incompatible
19135 cluster already present in @var{data-directory}. Adjust it (or, if you
19136 don't need the cluster anymore, delete @var{data-directory}), then
19137 restart the service.
19139 Peer authentication is used by default and the @code{postgres} user
19140 account has no shell, which prevents the direct execution of @code{psql}
19141 commands as this user. To use @code{psql}, you can temporarily log in
19142 as @code{postgres} using a shell, create a PostgreSQL superuser with the
19143 same name as one of the system users and then create the associated
19147 sudo -u postgres -s /bin/sh
19148 createuser --interactive
19149 createdb $MY_USER_LOGIN # Replace appropriately.
19152 @deftp {Data Type} postgresql-configuration
19153 Data type representing the configuration for the
19154 @code{postgresql-service-type}.
19157 @item @code{postgresql}
19158 PostgreSQL package to use for the service.
19160 @item @code{port} (default: @code{5432})
19161 Port on which PostgreSQL should listen.
19163 @item @code{locale} (default: @code{"en_US.utf8"})
19164 Locale to use as the default when creating the database cluster.
19166 @item @code{config-file} (default: @code{(postgresql-config-file)})
19167 The configuration file to use when running PostgreSQL. The default
19168 behaviour uses the postgresql-config-file record with the default values
19171 @item @code{data-directory} (default: @code{"/var/lib/postgresql/data"})
19172 Directory in which to store the data.
19174 @item @code{extension-packages} (default: @code{'()})
19175 @cindex postgresql extension-packages
19176 Additional extensions are loaded from packages listed in
19177 @var{extension-packages}. Extensions are available at runtime. For instance,
19178 to create a geographic database using the @code{postgis} extension, a user can
19179 configure the postgresql-service as in this example:
19183 (use-package-modules databases geo)
19187 ;; postgresql is required to run `psql' but postgis is not required for
19188 ;; proper operation.
19189 (packages (cons* postgresql %base-packages))
19192 (service postgresql-service-type
19193 (postgresql-configuration
19194 (postgresql postgresql-10)
19195 (extension-packages (list postgis))))
19199 Then the extension becomes visible and you can initialise an empty geographic
19200 database in this way:
19204 > create database postgistest;
19205 > \connect postgistest;
19206 > create extension postgis;
19207 > create extension postgis_topology;
19210 There is no need to add this field for contrib extensions such as hstore or
19211 dblink as they are already loadable by postgresql. This field is only
19212 required to add extensions provided by other packages.
19217 @deftp {Data Type} postgresql-config-file
19218 Data type representing the PostgreSQL configuration file. As shown in
19219 the following example, this can be used to customize the configuration
19220 of PostgreSQL. Note that you can use any G-expression or filename in
19221 place of this record, if you already have a configuration file you'd
19222 like to use for example.
19225 (service postgresql-service-type
19226 (postgresql-configuration
19228 (postgresql-config-file
19229 (log-destination "stderr")
19231 (plain-file "pg_hba.conf"
19233 local all all trust
19234 host all all 127.0.0.1/32 md5
19235 host all all ::1/128 md5"))
19237 '(("session_preload_libraries" "'auto_explain'")
19238 ("random_page_cost" "2")
19239 ("auto_explain.log_min_duration" "'100ms'")
19240 ("work_mem" "'500MB'")
19241 ("logging_collector" "on")
19242 ("log_directory" "'/var/log/postgresql'")))))))
19246 @item @code{log-destination} (default: @code{"syslog"})
19247 The logging method to use for PostgreSQL. Multiple values are accepted,
19248 separated by commas.
19250 @item @code{hba-file} (default: @code{%default-postgres-hba})
19251 Filename or G-expression for the host-based authentication
19254 @item @code{ident-file} (default: @code{%default-postgres-ident})
19255 Filename or G-expression for the user name mapping configuration.
19257 @item @code{extra-config} (default: @code{'()})
19258 List of additional keys and values to include in the PostgreSQL config
19259 file. Each entry in the list should be a list where the first element
19260 is the key, and the remaining elements are the values.
19265 @subsubheading MariaDB/MySQL
19267 @defvr {Scheme Variable} mysql-service-type
19268 This is the service type for a MySQL or MariaDB database server. Its value
19269 is a @code{mysql-configuration} object that specifies which package to use,
19270 as well as various settings for the @command{mysqld} daemon.
19273 @deftp {Data Type} mysql-configuration
19274 Data type representing the configuration of @var{mysql-service-type}.
19277 @item @code{mysql} (default: @var{mariadb})
19278 Package object of the MySQL database server, can be either @var{mariadb}
19281 For MySQL, a temporary root password will be displayed at activation time.
19282 For MariaDB, the root password is empty.
19284 @item @code{bind-address} (default: @code{"127.0.0.1"})
19285 The IP on which to listen for network connections. Use @code{"0.0.0.0"}
19286 to bind to all available network interfaces.
19288 @item @code{port} (default: @code{3306})
19289 TCP port on which the database server listens for incoming connections.
19291 @item @code{socket} (default: @code{"/run/mysqld/mysqld.sock"})
19292 Socket file to use for local (non-network) connections.
19294 @item @code{extra-content} (default: @code{""})
19295 Additional settings for the @file{my.cnf} configuration file.
19297 @item @code{auto-upgrade?} (default: @code{#t})
19298 Whether to automatically run @command{mysql_upgrade} after starting the
19299 service. This is necessary to upgrade the @dfn{system schema} after
19300 ``major'' updates (such as switching from MariaDB 10.4 to 10.5), but can
19301 be disabled if you would rather do that manually.
19306 @subsubheading Memcached
19308 @defvr {Scheme Variable} memcached-service-type
19309 This is the service type for the @uref{https://memcached.org/,
19310 Memcached} service, which provides a distributed in memory cache. The
19311 value for the service type is a @code{memcached-configuration} object.
19315 (service memcached-service-type)
19318 @deftp {Data Type} memcached-configuration
19319 Data type representing the configuration of memcached.
19322 @item @code{memcached} (default: @code{memcached})
19323 The Memcached package to use.
19325 @item @code{interfaces} (default: @code{'("0.0.0.0")})
19326 Network interfaces on which to listen.
19328 @item @code{tcp-port} (default: @code{11211})
19329 Port on which to accept connections.
19331 @item @code{udp-port} (default: @code{11211})
19332 Port on which to accept UDP connections on, a value of 0 will disable
19333 listening on a UDP socket.
19335 @item @code{additional-options} (default: @code{'()})
19336 Additional command line options to pass to @code{memcached}.
19340 @subsubheading MongoDB
19342 @defvr {Scheme Variable} mongodb-service-type
19343 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
19344 The value for the service type is a @code{mongodb-configuration} object.
19348 (service mongodb-service-type)
19351 @deftp {Data Type} mongodb-configuration
19352 Data type representing the configuration of mongodb.
19355 @item @code{mongodb} (default: @code{mongodb})
19356 The MongoDB package to use.
19358 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
19359 The configuration file for MongoDB.
19361 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
19362 This value is used to create the directory, so that it exists and is
19363 owned by the mongodb user. It should match the data-directory which
19364 MongoDB is configured to use through the configuration file.
19368 @subsubheading Redis
19370 @defvr {Scheme Variable} redis-service-type
19371 This is the service type for the @uref{https://redis.io/, Redis}
19372 key/value store, whose value is a @code{redis-configuration} object.
19375 @deftp {Data Type} redis-configuration
19376 Data type representing the configuration of redis.
19379 @item @code{redis} (default: @code{redis})
19380 The Redis package to use.
19382 @item @code{bind} (default: @code{"127.0.0.1"})
19383 Network interface on which to listen.
19385 @item @code{port} (default: @code{6379})
19386 Port on which to accept connections on, a value of 0 will disable
19387 listening on a TCP socket.
19389 @item @code{working-directory} (default: @code{"/var/lib/redis"})
19390 Directory in which to store the database and related files.
19394 @node Mail Services
19395 @subsection Mail Services
19399 The @code{(gnu services mail)} module provides Guix service definitions
19400 for email services: IMAP, POP3, and LMTP servers, as well as mail
19401 transport agents (MTAs). Lots of acronyms! These services are detailed
19402 in the subsections below.
19404 @subsubheading Dovecot Service
19406 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
19407 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
19410 By default, Dovecot does not need much configuration; the default
19411 configuration object created by @code{(dovecot-configuration)} will
19412 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
19413 certificate will be generated for TLS-protected connections, though
19414 Dovecot will also listen on cleartext ports by default. There are a
19415 number of options, though, which mail administrators might need to change,
19416 and as is the case with other services, Guix allows the system
19417 administrator to specify these parameters via a uniform Scheme interface.
19419 For example, to specify that mail is located at @code{maildir~/.mail},
19420 one would instantiate the Dovecot service like this:
19423 (dovecot-service #:config
19424 (dovecot-configuration
19425 (mail-location "maildir:~/.mail")))
19428 The available configuration parameters follow. Each parameter
19429 definition is preceded by its type; for example, @samp{string-list foo}
19430 indicates that the @code{foo} parameter should be specified as a list of
19431 strings. There is also a way to specify the configuration as a string,
19432 if you have an old @code{dovecot.conf} file that you want to port over
19433 from some other system; see the end for more details.
19435 @c The following documentation was initially generated by
19436 @c (generate-documentation) in (gnu services mail). Manually maintained
19437 @c documentation is better, so we shouldn't hesitate to edit below as
19438 @c needed. However if the change you want to make to this documentation
19439 @c can be done in an automated way, it's probably easier to change
19440 @c (generate-documentation) than to make it below and have to deal with
19441 @c the churn as dovecot updates.
19443 Available @code{dovecot-configuration} fields are:
19445 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
19446 The dovecot package.
19449 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
19450 A list of IPs or hosts where to listen for connections. @samp{*}
19451 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
19452 interfaces. If you want to specify non-default ports or anything more
19453 complex, customize the address and port fields of the
19454 @samp{inet-listener} of the specific services you are interested in.
19457 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
19458 List of protocols we want to serve. Available protocols include
19459 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
19461 Available @code{protocol-configuration} fields are:
19463 @deftypevr {@code{protocol-configuration} parameter} string name
19464 The name of the protocol.
19467 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
19468 UNIX socket path to the master authentication server to find users.
19469 This is used by imap (for shared users) and lda.
19470 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
19473 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
19474 Space separated list of plugins to load.
19477 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
19478 Maximum number of IMAP connections allowed for a user from each IP
19479 address. NOTE: The username is compared case-sensitively.
19480 Defaults to @samp{10}.
19485 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
19486 List of services to enable. Available services include @samp{imap},
19487 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
19490 Available @code{service-configuration} fields are:
19492 @deftypevr {@code{service-configuration} parameter} string kind
19493 The service kind. Valid values include @code{director},
19494 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
19495 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
19496 @code{tcpwrap}, @code{quota-warning}, or anything else.
19499 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
19500 Listeners for the service. A listener is either a
19501 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
19502 an @code{inet-listener-configuration}.
19503 Defaults to @samp{()}.
19505 Available @code{unix-listener-configuration} fields are:
19507 @deftypevr {@code{unix-listener-configuration} parameter} string path
19508 Path to the file, relative to @code{base-dir} field. This is also used as
19512 @deftypevr {@code{unix-listener-configuration} parameter} string mode
19513 The access mode for the socket.
19514 Defaults to @samp{"0600"}.
19517 @deftypevr {@code{unix-listener-configuration} parameter} string user
19518 The user to own the socket.
19519 Defaults to @samp{""}.
19522 @deftypevr {@code{unix-listener-configuration} parameter} string group
19523 The group to own the socket.
19524 Defaults to @samp{""}.
19528 Available @code{fifo-listener-configuration} fields are:
19530 @deftypevr {@code{fifo-listener-configuration} parameter} string path
19531 Path to the file, relative to @code{base-dir} field. This is also used as
19535 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
19536 The access mode for the socket.
19537 Defaults to @samp{"0600"}.
19540 @deftypevr {@code{fifo-listener-configuration} parameter} string user
19541 The user to own the socket.
19542 Defaults to @samp{""}.
19545 @deftypevr {@code{fifo-listener-configuration} parameter} string group
19546 The group to own the socket.
19547 Defaults to @samp{""}.
19551 Available @code{inet-listener-configuration} fields are:
19553 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
19554 The protocol to listen for.
19557 @deftypevr {@code{inet-listener-configuration} parameter} string address
19558 The address on which to listen, or empty for all addresses.
19559 Defaults to @samp{""}.
19562 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
19563 The port on which to listen.
19566 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
19567 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
19569 Defaults to @samp{#t}.
19574 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
19575 Maximum number of simultaneous client connections per process. Once
19576 this number of connections is received, the next incoming connection
19577 will prompt Dovecot to spawn another process. If set to 0,
19578 @code{default-client-limit} is used instead.
19580 Defaults to @samp{0}.
19584 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
19585 Number of connections to handle before starting a new process.
19586 Typically the only useful values are 0 (unlimited) or 1. 1 is more
19587 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
19588 Defaults to @samp{1}.
19592 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
19593 Maximum number of processes that can exist for this service. If set to
19594 0, @code{default-process-limit} is used instead.
19596 Defaults to @samp{0}.
19600 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
19601 Number of processes to always keep waiting for more connections.
19602 Defaults to @samp{0}.
19605 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
19606 If you set @samp{service-count 0}, you probably need to grow
19608 Defaults to @samp{256000000}.
19613 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
19614 Dict configuration, as created by the @code{dict-configuration}
19617 Available @code{dict-configuration} fields are:
19619 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
19620 A list of key-value pairs that this dict should hold.
19621 Defaults to @samp{()}.
19626 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
19627 A list of passdb configurations, each one created by the
19628 @code{passdb-configuration} constructor.
19630 Available @code{passdb-configuration} fields are:
19632 @deftypevr {@code{passdb-configuration} parameter} string driver
19633 The driver that the passdb should use. Valid values include
19634 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
19636 Defaults to @samp{"pam"}.
19639 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
19640 Space separated list of arguments to the passdb driver.
19641 Defaults to @samp{""}.
19646 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
19647 List of userdb configurations, each one created by the
19648 @code{userdb-configuration} constructor.
19650 Available @code{userdb-configuration} fields are:
19652 @deftypevr {@code{userdb-configuration} parameter} string driver
19653 The driver that the userdb should use. Valid values include
19654 @samp{passwd} and @samp{static}.
19655 Defaults to @samp{"passwd"}.
19658 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
19659 Space separated list of arguments to the userdb driver.
19660 Defaults to @samp{""}.
19663 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
19664 Override fields from passwd.
19665 Defaults to @samp{()}.
19670 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
19671 Plug-in configuration, created by the @code{plugin-configuration}
19675 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
19676 List of namespaces. Each item in the list is created by the
19677 @code{namespace-configuration} constructor.
19679 Available @code{namespace-configuration} fields are:
19681 @deftypevr {@code{namespace-configuration} parameter} string name
19682 Name for this namespace.
19685 @deftypevr {@code{namespace-configuration} parameter} string type
19686 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
19687 Defaults to @samp{"private"}.
19690 @deftypevr {@code{namespace-configuration} parameter} string separator
19691 Hierarchy separator to use. You should use the same separator for
19692 all namespaces or some clients get confused. @samp{/} is usually a good
19693 one. The default however depends on the underlying mail storage
19695 Defaults to @samp{""}.
19698 @deftypevr {@code{namespace-configuration} parameter} string prefix
19699 Prefix required to access this namespace. This needs to be
19700 different for all namespaces. For example @samp{Public/}.
19701 Defaults to @samp{""}.
19704 @deftypevr {@code{namespace-configuration} parameter} string location
19705 Physical location of the mailbox. This is in the same format as
19706 mail_location, which is also the default for it.
19707 Defaults to @samp{""}.
19710 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
19711 There can be only one INBOX, and this setting defines which
19713 Defaults to @samp{#f}.
19716 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
19717 If namespace is hidden, it's not advertised to clients via NAMESPACE
19718 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
19719 useful when converting from another server with different namespaces
19720 which you want to deprecate but still keep working. For example you can
19721 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
19723 Defaults to @samp{#f}.
19726 @deftypevr {@code{namespace-configuration} parameter} boolean list?
19727 Show the mailboxes under this namespace with the LIST command. This
19728 makes the namespace visible for clients that do not support the NAMESPACE
19729 extension. The special @code{children} value lists child mailboxes, but
19730 hides the namespace prefix.
19731 Defaults to @samp{#t}.
19734 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
19735 Namespace handles its own subscriptions. If set to @code{#f}, the
19736 parent namespace handles them. The empty prefix should always have this
19738 Defaults to @samp{#t}.
19741 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
19742 List of predefined mailboxes in this namespace.
19743 Defaults to @samp{()}.
19745 Available @code{mailbox-configuration} fields are:
19747 @deftypevr {@code{mailbox-configuration} parameter} string name
19748 Name for this mailbox.
19751 @deftypevr {@code{mailbox-configuration} parameter} string auto
19752 @samp{create} will automatically create this mailbox.
19753 @samp{subscribe} will both create and subscribe to the mailbox.
19754 Defaults to @samp{"no"}.
19757 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
19758 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
19759 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
19760 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
19761 Defaults to @samp{()}.
19768 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
19769 Base directory where to store runtime data.
19770 Defaults to @samp{"/var/run/dovecot/"}.
19773 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
19774 Greeting message for clients.
19775 Defaults to @samp{"Dovecot ready."}.
19778 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
19779 List of trusted network ranges. Connections from these IPs are
19780 allowed to override their IP addresses and ports (for logging and for
19781 authentication checks). @samp{disable-plaintext-auth} is also ignored
19782 for these networks. Typically you would specify your IMAP proxy servers
19784 Defaults to @samp{()}.
19787 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
19788 List of login access check sockets (e.g.@: tcpwrap).
19789 Defaults to @samp{()}.
19792 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
19793 Show more verbose process titles (in ps). Currently shows user name
19794 and IP address. Useful for seeing who is actually using the IMAP
19795 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
19797 Defaults to @samp{#f}.
19800 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
19801 Should all processes be killed when Dovecot master process shuts down.
19802 Setting this to @code{#f} means that Dovecot can be upgraded without
19803 forcing existing client connections to close (although that could also
19804 be a problem if the upgrade is e.g.@: due to a security fix).
19805 Defaults to @samp{#t}.
19808 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
19809 If non-zero, run mail commands via this many connections to doveadm
19810 server, instead of running them directly in the same process.
19811 Defaults to @samp{0}.
19814 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
19815 UNIX socket or host:port used for connecting to doveadm server.
19816 Defaults to @samp{"doveadm-server"}.
19819 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
19820 List of environment variables that are preserved on Dovecot startup
19821 and passed down to all of its child processes. You can also give
19822 key=value pairs to always set specific settings.
19825 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
19826 Disable LOGIN command and all other plaintext authentications unless
19827 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
19828 matches the local IP (i.e.@: you're connecting from the same computer),
19829 the connection is considered secure and plaintext authentication is
19830 allowed. See also ssl=required setting.
19831 Defaults to @samp{#t}.
19834 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
19835 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
19836 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
19837 for caching to be used.
19838 Defaults to @samp{0}.
19841 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
19842 Time to live for cached data. After TTL expires the cached record
19843 is no longer used, *except* if the main database lookup returns internal
19844 failure. We also try to handle password changes automatically: If
19845 user's previous authentication was successful, but this one wasn't, the
19846 cache isn't used. For now this works only with plaintext
19848 Defaults to @samp{"1 hour"}.
19851 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
19852 TTL for negative hits (user not found, password mismatch).
19853 0 disables caching them completely.
19854 Defaults to @samp{"1 hour"}.
19857 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
19858 List of realms for SASL authentication mechanisms that need them.
19859 You can leave it empty if you don't want to support multiple realms.
19860 Many clients simply use the first one listed here, so keep the default
19862 Defaults to @samp{()}.
19865 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
19866 Default realm/domain to use if none was specified. This is used for
19867 both SASL realms and appending @@domain to username in plaintext
19869 Defaults to @samp{""}.
19872 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
19873 List of allowed characters in username. If the user-given username
19874 contains a character not listed in here, the login automatically fails.
19875 This is just an extra check to make sure user can't exploit any
19876 potential quote escaping vulnerabilities with SQL/LDAP databases. If
19877 you want to allow all characters, set this value to empty.
19878 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
19881 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
19882 Username character translations before it's looked up from
19883 databases. The value contains series of from -> to characters. For
19884 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
19885 translated to @samp{@@}.
19886 Defaults to @samp{""}.
19889 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
19890 Username formatting before it's looked up from databases. You can
19891 use the standard variables here, e.g.@: %Lu would lowercase the username,
19892 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
19893 change the @samp{@@} into @samp{-AT-}. This translation is done after
19894 @samp{auth-username-translation} changes.
19895 Defaults to @samp{"%Lu"}.
19898 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
19899 If you want to allow master users to log in by specifying the master
19900 username within the normal username string (i.e.@: not using SASL
19901 mechanism's support for it), you can specify the separator character
19902 here. The format is then <username><separator><master username>.
19903 UW-IMAP uses @samp{*} as the separator, so that could be a good
19905 Defaults to @samp{""}.
19908 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
19909 Username to use for users logging in with ANONYMOUS SASL
19911 Defaults to @samp{"anonymous"}.
19914 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
19915 Maximum number of dovecot-auth worker processes. They're used to
19916 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
19917 They're automatically created and destroyed as needed.
19918 Defaults to @samp{30}.
19921 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
19922 Host name to use in GSSAPI principal names. The default is to use
19923 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
19924 allow all keytab entries.
19925 Defaults to @samp{""}.
19928 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
19929 Kerberos keytab to use for the GSSAPI mechanism. Will use the
19930 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
19931 need to change the auth service to run as root to be able to read this
19933 Defaults to @samp{""}.
19936 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
19937 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
19938 and @samp{ntlm-auth} helper.
19939 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
19940 Defaults to @samp{#f}.
19943 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
19944 Path for Samba's @samp{ntlm-auth} helper binary.
19945 Defaults to @samp{"/usr/bin/ntlm_auth"}.
19948 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
19949 Time to delay before replying to failed authentications.
19950 Defaults to @samp{"2 secs"}.
19953 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
19954 Require a valid SSL client certificate or the authentication
19956 Defaults to @samp{#f}.
19959 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
19960 Take the username from client's SSL certificate, using
19961 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
19963 Defaults to @samp{#f}.
19966 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
19967 List of wanted authentication mechanisms. Supported mechanisms are:
19968 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
19969 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
19970 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
19971 @samp{disable-plaintext-auth} setting.
19974 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
19975 List of IPs or hostnames to all director servers, including ourself.
19976 Ports can be specified as ip:port. The default port is the same as what
19977 director service's @samp{inet-listener} is using.
19978 Defaults to @samp{()}.
19981 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
19982 List of IPs or hostnames to all backend mail servers. Ranges are
19983 allowed too, like 10.0.0.10-10.0.0.30.
19984 Defaults to @samp{()}.
19987 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
19988 How long to redirect users to a specific server after it no longer
19989 has any connections.
19990 Defaults to @samp{"15 min"}.
19993 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
19994 How the username is translated before being hashed. Useful values
19995 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
19996 are shared within domain.
19997 Defaults to @samp{"%Lu"}.
20000 @deftypevr {@code{dovecot-configuration} parameter} string log-path
20001 Log file to use for error messages. @samp{syslog} logs to syslog,
20002 @samp{/dev/stderr} logs to stderr.
20003 Defaults to @samp{"syslog"}.
20006 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
20007 Log file to use for informational messages. Defaults to
20009 Defaults to @samp{""}.
20012 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
20013 Log file to use for debug messages. Defaults to
20014 @samp{info-log-path}.
20015 Defaults to @samp{""}.
20018 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
20019 Syslog facility to use if you're logging to syslog. Usually if you
20020 don't want to use @samp{mail}, you'll use local0..local7. Also other
20021 standard facilities are supported.
20022 Defaults to @samp{"mail"}.
20025 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
20026 Log unsuccessful authentication attempts and the reasons why they
20028 Defaults to @samp{#f}.
20031 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
20032 In case of password mismatches, log the attempted password. Valid
20033 values are no, plain and sha1. sha1 can be useful for detecting brute
20034 force password attempts vs. user simply trying the same password over
20035 and over again. You can also truncate the value to n chars by appending
20036 ":n" (e.g.@: sha1:6).
20037 Defaults to @samp{"no"}.
20040 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
20041 Even more verbose logging for debugging purposes. Shows for example
20043 Defaults to @samp{#f}.
20046 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
20047 In case of password mismatches, log the passwords and used scheme so
20048 the problem can be debugged. Enabling this also enables
20050 Defaults to @samp{#f}.
20053 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
20054 Enable mail process debugging. This can help you figure out why
20055 Dovecot isn't finding your mails.
20056 Defaults to @samp{#f}.
20059 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
20060 Show protocol level SSL errors.
20061 Defaults to @samp{#f}.
20064 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
20065 Prefix for each line written to log file. % codes are in
20066 strftime(3) format.
20067 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
20070 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
20071 List of elements we want to log. The elements which have a
20072 non-empty variable value are joined together to form a comma-separated
20076 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
20077 Login log format. %s contains @samp{login-log-format-elements}
20078 string, %$ contains the data we want to log.
20079 Defaults to @samp{"%$: %s"}.
20082 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
20083 Log prefix for mail processes. See doc/wiki/Variables.txt for list
20084 of possible variables you can use.
20085 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
20088 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
20089 Format to use for logging mail deliveries. You can use variables:
20092 Delivery status message (e.g.@: @samp{saved to INBOX})
20104 Defaults to @samp{"msgid=%m: %$"}.
20107 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
20108 Location for users' mailboxes. The default is empty, which means
20109 that Dovecot tries to find the mailboxes automatically. This won't work
20110 if the user doesn't yet have any mail, so you should explicitly tell
20111 Dovecot the full location.
20113 If you're using mbox, giving a path to the INBOX
20114 file (e.g.@: @file{/var/mail/%u}) isn't enough. You'll also need to tell Dovecot
20115 where the other mailboxes are kept. This is called the @emph{root mail
20116 directory}, and it must be the first path given in the
20117 @samp{mail-location} setting.
20119 There are a few special variables you can use, e.g.:
20125 user part in user@@domain, same as %u if there's no domain
20127 domain part in user@@domain, empty if there's no domain
20132 See doc/wiki/Variables.txt for full list. Some examples:
20134 @item maildir:~/Maildir
20135 @item mbox:~/mail:INBOX=/var/mail/%u
20136 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
20138 Defaults to @samp{""}.
20141 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
20142 System user and group used to access mails. If you use multiple,
20143 userdb can override these by returning uid or gid fields. You can use
20144 either numbers or names. <doc/wiki/UserIds.txt>.
20145 Defaults to @samp{""}.
20148 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
20150 Defaults to @samp{""}.
20153 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
20154 Group to enable temporarily for privileged operations. Currently
20155 this is used only with INBOX when either its initial creation or
20156 dotlocking fails. Typically this is set to @samp{"mail"} to give access to
20158 Defaults to @samp{""}.
20161 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
20162 Grant access to these supplementary groups for mail processes.
20163 Typically these are used to set up access to shared mailboxes. Note
20164 that it may be dangerous to set these if users can create symlinks
20165 (e.g.@: if @samp{mail} group is set here, @code{ln -s /var/mail ~/mail/var}
20166 could allow a user to delete others' mailboxes, or @code{ln -s
20167 /secret/shared/box ~/mail/mybox} would allow reading it). Defaults to
20171 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
20172 Allow full file system access to clients. There's no access checks
20173 other than what the operating system does for the active UID/GID. It
20174 works with both maildir and mboxes, allowing you to prefix mailboxes
20175 names with e.g.@: @file{/path/} or @file{~user/}.
20176 Defaults to @samp{#f}.
20179 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
20180 Don't use @code{mmap()} at all. This is required if you store indexes to
20181 shared file systems (NFS or clustered file system).
20182 Defaults to @samp{#f}.
20185 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
20186 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
20187 supports @samp{O_EXCL} since version 3, so this should be safe to use
20188 nowadays by default.
20189 Defaults to @samp{#t}.
20192 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
20193 When to use fsync() or fdatasync() calls:
20196 Whenever necessary to avoid losing important data
20198 Useful with e.g.@: NFS when @code{write()}s are delayed
20200 Never use it (best performance, but crashes can lose data).
20202 Defaults to @samp{"optimized"}.
20205 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
20206 Mail storage exists in NFS. Set this to yes to make Dovecot flush
20207 NFS caches whenever needed. If you're using only a single mail server
20209 Defaults to @samp{#f}.
20212 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
20213 Mail index files also exist in NFS. Setting this to yes requires
20214 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
20215 Defaults to @samp{#f}.
20218 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
20219 Locking method for index files. Alternatives are fcntl, flock and
20220 dotlock. Dotlocking uses some tricks which may create more disk I/O
20221 than other locking methods. NFS users: flock doesn't work, remember to
20222 change @samp{mmap-disable}.
20223 Defaults to @samp{"fcntl"}.
20226 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
20227 Directory in which LDA/LMTP temporarily stores incoming mails >128
20229 Defaults to @samp{"/tmp"}.
20232 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
20233 Valid UID range for users. This is mostly to make sure that users can't
20234 log in as daemons or other system users. Note that denying root logins is
20235 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
20237 Defaults to @samp{500}.
20240 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
20242 Defaults to @samp{0}.
20245 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
20246 Valid GID range for users. Users having non-valid GID as primary group ID
20247 aren't allowed to log in. If user belongs to supplementary groups with
20248 non-valid GIDs, those groups are not set.
20249 Defaults to @samp{1}.
20252 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
20254 Defaults to @samp{0}.
20257 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
20258 Maximum allowed length for mail keyword name. It's only forced when
20259 trying to create new keywords.
20260 Defaults to @samp{50}.
20263 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
20264 List of directories under which chrooting is allowed for mail
20265 processes (i.e.@: @file{/var/mail} will allow chrooting to @file{/var/mail/foo/bar}
20266 too). This setting doesn't affect @samp{login-chroot}
20267 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
20268 @samp{/./} in home dirs are ignored. WARNING: Never add directories here
20269 which local users can modify, that may lead to root exploit. Usually
20270 this should be done only if you don't allow shell access for users.
20271 <doc/wiki/Chrooting.txt>.
20272 Defaults to @samp{()}.
20275 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
20276 Default chroot directory for mail processes. This can be overridden
20277 for specific users in user database by giving @samp{/./} in user's home
20278 directory (e.g.@: @samp{/home/./user} chroots into @file{/home}). Note that usually
20279 there is no real need to do chrooting, Dovecot doesn't allow users to
20280 access files outside their mail directory anyway. If your home
20281 directories are prefixed with the chroot directory, append @samp{/.} to
20282 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
20283 Defaults to @samp{""}.
20286 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
20287 UNIX socket path to master authentication server to find users.
20288 This is used by imap (for shared users) and lda.
20289 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
20292 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
20293 Directory where to look up mail plugins.
20294 Defaults to @samp{"/usr/lib/dovecot"}.
20297 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
20298 List of plugins to load for all services. Plugins specific to IMAP,
20299 LDA, etc.@: are added to this list in their own .conf files.
20300 Defaults to @samp{()}.
20303 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
20304 The minimum number of mails in a mailbox before updates are done to
20305 cache file. This allows optimizing Dovecot's behavior to do less disk
20306 writes at the cost of more disk reads.
20307 Defaults to @samp{0}.
20310 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
20311 When IDLE command is running, mailbox is checked once in a while to
20312 see if there are any new mails or other changes. This setting defines
20313 the minimum time to wait between those checks. Dovecot can also use
20314 dnotify, inotify and kqueue to find out immediately when changes
20316 Defaults to @samp{"30 secs"}.
20319 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
20320 Save mails with CR+LF instead of plain LF. This makes sending those
20321 mails take less CPU, especially with sendfile() syscall with Linux and
20322 FreeBSD. But it also creates a bit more disk I/O which may just make it
20323 slower. Also note that if other software reads the mboxes/maildirs,
20324 they may handle the extra CRs wrong and cause problems.
20325 Defaults to @samp{#f}.
20328 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
20329 By default LIST command returns all entries in maildir beginning
20330 with a dot. Enabling this option makes Dovecot return only entries
20331 which are directories. This is done by stat()ing each entry, so it
20332 causes more disk I/O.
20333 (For systems setting struct @samp{dirent->d_type} this check is free
20334 and it's done always regardless of this setting).
20335 Defaults to @samp{#f}.
20338 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
20339 When copying a message, do it with hard links whenever possible.
20340 This makes the performance much better, and it's unlikely to have any
20342 Defaults to @samp{#t}.
20345 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
20346 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
20347 directory only when its mtime changes unexpectedly or when we can't find
20348 the mail otherwise.
20349 Defaults to @samp{#f}.
20352 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
20353 Which locking methods to use for locking mbox. There are four
20358 Create <mailbox>.lock file. This is the oldest and most NFS-safe
20359 solution. If you want to use /var/mail/ like directory, the users will
20360 need write access to that directory.
20362 Same as dotlock, but if it fails because of permissions or because there
20363 isn't enough disk space, just skip it.
20365 Use this if possible. Works with NFS too if lockd is used.
20367 May not exist in all systems. Doesn't work with NFS.
20369 May not exist in all systems. Doesn't work with NFS.
20372 You can use multiple locking methods; if you do the order they're declared
20373 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
20374 locking methods as well. Some operating systems don't allow using some of
20375 them simultaneously.
20378 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
20382 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
20383 Maximum time to wait for lock (all of them) before aborting.
20384 Defaults to @samp{"5 mins"}.
20387 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
20388 If dotlock exists but the mailbox isn't modified in any way,
20389 override the lock file after this much time.
20390 Defaults to @samp{"2 mins"}.
20393 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
20394 When mbox changes unexpectedly we have to fully read it to find out
20395 what changed. If the mbox is large this can take a long time. Since
20396 the change is usually just a newly appended mail, it'd be faster to
20397 simply read the new mails. If this setting is enabled, Dovecot does
20398 this but still safely fallbacks to re-reading the whole mbox file
20399 whenever something in mbox isn't how it's expected to be. The only real
20400 downside to this setting is that if some other MUA changes message
20401 flags, Dovecot doesn't notice it immediately. Note that a full sync is
20402 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
20403 Defaults to @samp{#t}.
20406 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
20407 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
20408 EXAMINE, EXPUNGE or CHECK commands. If this is set,
20409 @samp{mbox-dirty-syncs} is ignored.
20410 Defaults to @samp{#f}.
20413 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
20414 Delay writing mbox headers until doing a full write sync (EXPUNGE
20415 and CHECK commands and when closing the mailbox). This is especially
20416 useful for POP3 where clients often delete all mails. The downside is
20417 that our changes aren't immediately visible to other MUAs.
20418 Defaults to @samp{#t}.
20421 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
20422 If mbox size is smaller than this (e.g.@: 100k), don't write index
20423 files. If an index file already exists it's still read, just not
20425 Defaults to @samp{0}.
20428 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
20429 Maximum dbox file size until it's rotated.
20430 Defaults to @samp{10000000}.
20433 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
20434 Maximum dbox file age until it's rotated. Typically in days. Day
20435 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
20437 Defaults to @samp{"1d"}.
20440 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
20441 When creating new mdbox files, immediately preallocate their size to
20442 @samp{mdbox-rotate-size}. This setting currently works only in Linux
20443 with some file systems (ext4, xfs).
20444 Defaults to @samp{#f}.
20447 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
20448 sdbox and mdbox support saving mail attachments to external files,
20449 which also allows single instance storage for them. Other backends
20450 don't support this for now.
20452 WARNING: This feature hasn't been tested much yet. Use at your own risk.
20454 Directory root where to store mail attachments. Disabled, if empty.
20455 Defaults to @samp{""}.
20458 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
20459 Attachments smaller than this aren't saved externally. It's also
20460 possible to write a plugin to disable saving specific attachments
20462 Defaults to @samp{128000}.
20465 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
20466 File system backend to use for saving attachments:
20469 No SiS done by Dovecot (but this might help FS's own deduplication)
20471 SiS with immediate byte-by-byte comparison during saving
20472 @item sis-queue posix
20473 SiS with delayed comparison and deduplication.
20475 Defaults to @samp{"sis posix"}.
20478 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
20479 Hash format to use in attachment filenames. You can add any text and
20480 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
20481 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
20482 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
20483 Defaults to @samp{"%@{sha1@}"}.
20486 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
20488 Defaults to @samp{100}.
20491 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
20493 Defaults to @samp{1000}.
20496 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
20497 Default VSZ (virtual memory size) limit for service processes.
20498 This is mainly intended to catch and kill processes that leak memory
20499 before they eat up everything.
20500 Defaults to @samp{256000000}.
20503 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
20504 Login user is internally used by login processes. This is the most
20505 untrusted user in Dovecot system. It shouldn't have access to anything
20507 Defaults to @samp{"dovenull"}.
20510 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
20511 Internal user is used by unprivileged processes. It should be
20512 separate from login user, so that login processes can't disturb other
20514 Defaults to @samp{"dovecot"}.
20517 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
20518 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
20519 Defaults to @samp{"required"}.
20522 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
20523 PEM encoded X.509 SSL/TLS certificate (public key).
20524 Defaults to @samp{"</etc/dovecot/default.pem"}.
20527 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
20528 PEM encoded SSL/TLS private key. The key is opened before
20529 dropping root privileges, so keep the key file unreadable by anyone but
20531 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
20534 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
20535 If key file is password protected, give the password here.
20536 Alternatively give it when starting dovecot with -p parameter. Since
20537 this file is often world-readable, you may want to place this setting
20538 instead to a different.
20539 Defaults to @samp{""}.
20542 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
20543 PEM encoded trusted certificate authority. Set this only if you
20544 intend to use @samp{ssl-verify-client-cert? #t}. The file should
20545 contain the CA certificate(s) followed by the matching
20546 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
20547 Defaults to @samp{""}.
20550 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
20551 Require that CRL check succeeds for client certificates.
20552 Defaults to @samp{#t}.
20555 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
20556 Request client to send a certificate. If you also want to require
20557 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
20558 Defaults to @samp{#f}.
20561 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
20562 Which field from certificate to use for username. commonName and
20563 x500UniqueIdentifier are the usual choices. You'll also need to set
20564 @samp{auth-ssl-username-from-cert? #t}.
20565 Defaults to @samp{"commonName"}.
20568 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
20569 Minimum SSL protocol version to accept.
20570 Defaults to @samp{"TLSv1"}.
20573 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
20574 SSL ciphers to use.
20575 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
20578 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
20579 SSL crypto device to use, for valid values run "openssl engine".
20580 Defaults to @samp{""}.
20583 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
20584 Address to use when sending rejection mails.
20585 %d expands to recipient domain.
20586 Defaults to @samp{"postmaster@@%d"}.
20589 @deftypevr {@code{dovecot-configuration} parameter} string hostname
20590 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
20591 and in LMTP replies. Default is the system's real hostname@@domain.
20592 Defaults to @samp{""}.
20595 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
20596 If user is over quota, return with temporary failure instead of
20598 Defaults to @samp{#f}.
20601 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
20602 Binary to use for sending mails.
20603 Defaults to @samp{"/usr/sbin/sendmail"}.
20606 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
20607 If non-empty, send mails via this SMTP host[:port] instead of
20609 Defaults to @samp{""}.
20612 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
20613 Subject: header to use for rejection mails. You can use the same
20614 variables as for @samp{rejection-reason} below.
20615 Defaults to @samp{"Rejected: %s"}.
20618 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
20619 Human readable error message for rejection mails. You can use
20632 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
20635 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
20636 Delimiter character between local-part and detail in email
20638 Defaults to @samp{"+"}.
20641 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
20642 Header where the original recipient address (SMTP's RCPT TO:
20643 address) is taken from if not available elsewhere. With dovecot-lda -a
20644 parameter overrides this. A commonly used header for this is
20646 Defaults to @samp{""}.
20649 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
20650 Should saving a mail to a nonexistent mailbox automatically create
20652 Defaults to @samp{#f}.
20655 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
20656 Should automatically created mailboxes be also automatically
20658 Defaults to @samp{#f}.
20661 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
20662 Maximum IMAP command line length. Some clients generate very long
20663 command lines with huge mailboxes, so you may need to raise this if you
20664 get "Too long argument" or "IMAP command line too large" errors
20666 Defaults to @samp{64000}.
20669 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
20670 IMAP logout format string:
20673 total number of bytes read from client
20675 total number of bytes sent to client.
20677 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
20678 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@}"}.
20681 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
20682 Override the IMAP CAPABILITY response. If the value begins with '+',
20683 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
20684 Defaults to @samp{""}.
20687 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
20688 How long to wait between "OK Still here" notifications when client
20690 Defaults to @samp{"2 mins"}.
20693 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
20694 ID field names and values to send to clients. Using * as the value
20695 makes Dovecot use the default value. The following fields have default
20696 values currently: name, version, os, os-version, support-url,
20698 Defaults to @samp{""}.
20701 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
20702 ID fields sent by client to log. * means everything.
20703 Defaults to @samp{""}.
20706 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
20707 Workarounds for various client bugs:
20710 @item delay-newmail
20711 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
20712 CHECK commands. Some clients ignore them otherwise, for example OSX
20713 Mail (<v2.1). Outlook Express breaks more badly though, without this it
20714 may show user "Message no longer in server" errors. Note that OE6
20715 still breaks even with this workaround if synchronization is set to
20718 @item tb-extra-mailbox-sep
20719 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
20720 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
20721 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
20723 @item tb-lsub-flags
20724 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
20725 This makes Thunderbird realize they aren't selectable and show them
20726 greyed out, instead of only later giving "not selectable" popup error.
20728 Defaults to @samp{()}.
20731 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
20732 Host allowed in URLAUTH URLs sent by client. "*" allows all.
20733 Defaults to @samp{""}.
20737 Whew! Lots of configuration options. The nice thing about it though is
20738 that Guix has a complete interface to Dovecot's configuration
20739 language. This allows not only a nice way to declare configurations,
20740 but also offers reflective capabilities as well: users can write code to
20741 inspect and transform configurations from within Scheme.
20743 However, it could be that you just want to get a @code{dovecot.conf} up
20744 and running. In that case, you can pass an
20745 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
20746 @code{dovecot-service}. As its name indicates, an opaque configuration
20747 does not have easy reflective capabilities.
20749 Available @code{opaque-dovecot-configuration} fields are:
20751 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
20752 The dovecot package.
20755 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
20756 The contents of the @code{dovecot.conf}, as a string.
20759 For example, if your @code{dovecot.conf} is just the empty string, you
20760 could instantiate a dovecot service like this:
20763 (dovecot-service #:config
20764 (opaque-dovecot-configuration
20768 @subsubheading OpenSMTPD Service
20770 @deffn {Scheme Variable} opensmtpd-service-type
20771 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
20772 service, whose value should be an @code{opensmtpd-configuration} object
20773 as in this example:
20776 (service opensmtpd-service-type
20777 (opensmtpd-configuration
20778 (config-file (local-file "./my-smtpd.conf"))))
20782 @deftp {Data Type} opensmtpd-configuration
20783 Data type representing the configuration of opensmtpd.
20786 @item @code{package} (default: @var{opensmtpd})
20787 Package object of the OpenSMTPD SMTP server.
20789 @item @code{config-file} (default: @code{%default-opensmtpd-file})
20790 File-like object of the OpenSMTPD configuration file to use. By default
20791 it listens on the loopback network interface, and allows for mail from
20792 users and daemons on the local machine, as well as permitting email to
20793 remote servers. Run @command{man smtpd.conf} for more information.
20798 @subsubheading Exim Service
20800 @cindex mail transfer agent (MTA)
20801 @cindex MTA (mail transfer agent)
20804 @deffn {Scheme Variable} exim-service-type
20805 This is the type of the @uref{https://exim.org, Exim} mail transfer
20806 agent (MTA), whose value should be an @code{exim-configuration} object
20807 as in this example:
20810 (service exim-service-type
20811 (exim-configuration
20812 (config-file (local-file "./my-exim.conf"))))
20816 In order to use an @code{exim-service-type} service you must also have a
20817 @code{mail-aliases-service-type} service present in your
20818 @code{operating-system} (even if it has no aliases).
20820 @deftp {Data Type} exim-configuration
20821 Data type representing the configuration of exim.
20824 @item @code{package} (default: @var{exim})
20825 Package object of the Exim server.
20827 @item @code{config-file} (default: @code{#f})
20828 File-like object of the Exim configuration file to use. If its value is
20829 @code{#f} then use the default configuration file from the package
20830 provided in @code{package}. The resulting configuration file is loaded
20831 after setting the @code{exim_user} and @code{exim_group} configuration
20837 @subsubheading Getmail service
20842 @deffn {Scheme Variable} getmail-service-type
20843 This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
20844 mail retriever, whose value should be an @code{getmail-configuration}.
20847 Available @code{getmail-configuration} fields are:
20849 @deftypevr {@code{getmail-configuration} parameter} symbol name
20850 A symbol to identify the getmail service.
20852 Defaults to @samp{"unset"}.
20856 @deftypevr {@code{getmail-configuration} parameter} package package
20857 The getmail package to use.
20861 @deftypevr {@code{getmail-configuration} parameter} string user
20862 The user to run getmail as.
20864 Defaults to @samp{"getmail"}.
20868 @deftypevr {@code{getmail-configuration} parameter} string group
20869 The group to run getmail as.
20871 Defaults to @samp{"getmail"}.
20875 @deftypevr {@code{getmail-configuration} parameter} string directory
20876 The getmail directory to use.
20878 Defaults to @samp{"/var/lib/getmail/default"}.
20882 @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
20883 The getmail configuration file to use.
20885 Available @code{getmail-configuration-file} fields are:
20887 @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
20888 What mail account to retrieve mail from, and how to access that account.
20890 Available @code{getmail-retriever-configuration} fields are:
20892 @deftypevr {@code{getmail-retriever-configuration} parameter} string type
20893 The type of mail retriever to use. Valid values include @samp{passwd}
20896 Defaults to @samp{"SimpleIMAPSSLRetriever"}.
20900 @deftypevr {@code{getmail-retriever-configuration} parameter} string server
20901 Username to login to the mail server with.
20903 Defaults to @samp{unset}.
20907 @deftypevr {@code{getmail-retriever-configuration} parameter} string username
20908 Username to login to the mail server with.
20910 Defaults to @samp{unset}.
20914 @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
20915 Port number to connect to.
20917 Defaults to @samp{#f}.
20921 @deftypevr {@code{getmail-retriever-configuration} parameter} string password
20922 Override fields from passwd.
20924 Defaults to @samp{""}.
20928 @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
20929 Override fields from passwd.
20931 Defaults to @samp{()}.
20935 @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
20936 PEM-formatted key file to use for the TLS negotiation.
20938 Defaults to @samp{""}.
20942 @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
20943 PEM-formatted certificate file to use for the TLS negotiation.
20945 Defaults to @samp{""}.
20949 @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
20950 CA certificates to use.
20952 Defaults to @samp{""}.
20956 @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
20957 Extra retriever parameters.
20959 Defaults to @samp{()}.
20965 @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
20966 What to do with retrieved messages.
20968 Available @code{getmail-destination-configuration} fields are:
20970 @deftypevr {@code{getmail-destination-configuration} parameter} string type
20971 The type of mail destination. Valid values include @samp{Maildir},
20972 @samp{Mboxrd} and @samp{MDA_external}.
20974 Defaults to @samp{unset}.
20978 @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
20979 The path option for the mail destination. The behaviour depends on the
20982 Defaults to @samp{""}.
20986 @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
20987 Extra destination parameters
20989 Defaults to @samp{()}.
20995 @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
20998 Available @code{getmail-options-configuration} fields are:
21000 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
21001 If set to @samp{0}, getmail will only print warnings and errors. A
21002 value of @samp{1} means that messages will be printed about retrieving
21003 and deleting messages. If set to @samp{2}, getmail will print messages
21004 about each of it's actions.
21006 Defaults to @samp{1}.
21010 @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
21011 If true, getmail will retrieve all available messages. Otherwise it
21012 will only retrieve messages it hasn't seen previously.
21014 Defaults to @samp{#t}.
21018 @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
21019 If set to true, messages will be deleted from the server after
21020 retrieving and successfully delivering them. Otherwise, messages will
21021 be left on the server.
21023 Defaults to @samp{#f}.
21027 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
21028 Getmail will delete messages this number of days after seeing them, if
21029 they have been delivered. This means messages will be left on the
21030 server this number of days after delivering them. A value of @samp{0}
21031 disabled this feature.
21033 Defaults to @samp{0}.
21037 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
21038 Delete messages larger than this of bytes after retrieving them, even if
21039 the delete and delete-after options are disabled. A value of @samp{0}
21040 disables this feature.
21042 Defaults to @samp{0}.
21046 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
21047 Retrieve messages totalling up to this number of bytes before closing
21048 the session with the server. A value of @samp{0} disables this feature.
21050 Defaults to @samp{0}.
21054 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
21055 Don't retrieve messages larger than this number of bytes. A value of
21056 @samp{0} disables this feature.
21058 Defaults to @samp{0}.
21062 @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
21063 If true, getmail will add a Delivered-To header to messages.
21065 Defaults to @samp{#t}.
21069 @deftypevr {@code{getmail-options-configuration} parameter} boolean received
21070 If set, getmail adds a Received header to the messages.
21072 Defaults to @samp{#t}.
21076 @deftypevr {@code{getmail-options-configuration} parameter} string message-log
21077 Getmail will record a log of its actions to the named file. A value of
21078 @samp{""} disables this feature.
21080 Defaults to @samp{""}.
21084 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
21085 If true, getmail will record a log of its actions using the system
21088 Defaults to @samp{#f}.
21092 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
21093 If true, getmail will log information about messages not retrieved and
21094 the reason for not retrieving them, as well as starting and ending
21097 Defaults to @samp{#f}.
21101 @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
21102 Extra options to include.
21104 Defaults to @samp{()}.
21112 @deftypevr {@code{getmail-configuration} parameter} list idle
21113 A list of mailboxes that getmail should wait on the server for new mail
21114 notifications. This depends on the server supporting the IDLE
21117 Defaults to @samp{()}.
21121 @deftypevr {@code{getmail-configuration} parameter} list environment-variables
21122 Environment variables to set for getmail.
21124 Defaults to @samp{()}.
21128 @subsubheading Mail Aliases Service
21130 @cindex email aliases
21131 @cindex aliases, for email addresses
21133 @deffn {Scheme Variable} mail-aliases-service-type
21134 This is the type of the service which provides @code{/etc/aliases},
21135 specifying how to deliver mail to users on this system.
21138 (service mail-aliases-service-type
21139 '(("postmaster" "bob")
21140 ("bob" "bob@@example.com" "bob@@example2.com")))
21144 The configuration for a @code{mail-aliases-service-type} service is an
21145 association list denoting how to deliver mail that comes to this
21146 system. Each entry is of the form @code{(alias addresses ...)}, with
21147 @code{alias} specifying the local alias and @code{addresses} specifying
21148 where to deliver this user's mail.
21150 The aliases aren't required to exist as users on the local system. In
21151 the above example, there doesn't need to be a @code{postmaster} entry in
21152 the @code{operating-system}'s @code{user-accounts} in order to deliver
21153 the @code{postmaster} mail to @code{bob} (which subsequently would
21154 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
21156 @subsubheading GNU Mailutils IMAP4 Daemon
21157 @cindex GNU Mailutils IMAP4 Daemon
21159 @deffn {Scheme Variable} imap4d-service-type
21160 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
21161 mailutils, GNU Mailutils Manual}), whose value should be an
21162 @code{imap4d-configuration} object as in this example:
21165 (service imap4d-service-type
21166 (imap4d-configuration
21167 (config-file (local-file "imap4d.conf"))))
21171 @deftp {Data Type} imap4d-configuration
21172 Data type representing the configuration of @command{imap4d}.
21175 @item @code{package} (default: @code{mailutils})
21176 The package that provides @command{imap4d}.
21178 @item @code{config-file} (default: @code{%default-imap4d-config-file})
21179 File-like object of the configuration file to use, by default it will listen
21180 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
21181 Mailutils Manual}, for details.
21186 @node Messaging Services
21187 @subsection Messaging Services
21192 The @code{(gnu services messaging)} module provides Guix service
21193 definitions for messaging services. Currently it provides the following
21196 @subsubheading Prosody Service
21198 @deffn {Scheme Variable} prosody-service-type
21199 This is the type for the @uref{https://prosody.im, Prosody XMPP
21200 communication server}. Its value must be a @code{prosody-configuration}
21201 record as in this example:
21204 (service prosody-service-type
21205 (prosody-configuration
21206 (modules-enabled (cons* "groups" "mam" %default-modules-enabled))
21209 (int-component-configuration
21210 (hostname "conference.example.net")
21212 (mod-muc (mod-muc-configuration)))))
21215 (virtualhost-configuration
21216 (domain "example.net"))))))
21219 See below for details about @code{prosody-configuration}.
21223 By default, Prosody does not need much configuration. Only one
21224 @code{virtualhosts} field is needed: it specifies the domain you wish
21227 You can perform various sanity checks on the generated configuration
21228 with the @code{prosodyctl check} command.
21230 Prosodyctl will also help you to import certificates from the
21231 @code{letsencrypt} directory so that the @code{prosody} user can access
21232 them. See @url{https://prosody.im/doc/letsencrypt}.
21235 prosodyctl --root cert import /etc/letsencrypt/live
21238 The available configuration parameters follow. Each parameter
21239 definition is preceded by its type; for example, @samp{string-list foo}
21240 indicates that the @code{foo} parameter should be specified as a list of
21241 strings. Types starting with @code{maybe-} denote parameters that won't
21242 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
21244 There is also a way to specify the configuration as a string, if you
21245 have an old @code{prosody.cfg.lua} file that you want to port over from
21246 some other system; see the end for more details.
21248 The @code{file-object} type designates either a file-like object
21249 (@pxref{G-Expressions, file-like objects}) or a file name.
21251 @c The following documentation was initially generated by
21252 @c (generate-documentation) in (gnu services messaging). Manually maintained
21253 @c documentation is better, so we shouldn't hesitate to edit below as
21254 @c needed. However if the change you want to make to this documentation
21255 @c can be done in an automated way, it's probably easier to change
21256 @c (generate-documentation) than to make it below and have to deal with
21257 @c the churn as Prosody updates.
21259 Available @code{prosody-configuration} fields are:
21261 @deftypevr {@code{prosody-configuration} parameter} package prosody
21262 The Prosody package.
21265 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
21266 Location of the Prosody data storage directory. See
21267 @url{https://prosody.im/doc/configure}.
21268 Defaults to @samp{"/var/lib/prosody"}.
21271 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
21272 Additional plugin directories. They are searched in all the specified
21273 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
21274 Defaults to @samp{()}.
21277 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
21278 Every virtual host and component needs a certificate so that clients and
21279 servers can securely verify its identity. Prosody will automatically load
21280 certificates/keys from the directory specified here.
21281 Defaults to @samp{"/etc/prosody/certs"}.
21284 @deftypevr {@code{prosody-configuration} parameter} string-list admins
21285 This is a list of accounts that are admins for the server. Note that you
21286 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
21287 @url{https://prosody.im/doc/creating_accounts}.
21288 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
21289 Defaults to @samp{()}.
21292 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
21293 Enable use of libevent for better performance under high load. See
21294 @url{https://prosody.im/doc/libevent}.
21295 Defaults to @samp{#f}.
21298 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
21299 This is the list of modules Prosody will load on startup. It looks for
21300 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
21301 Documentation on modules can be found at:
21302 @url{https://prosody.im/doc/modules}.
21303 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
21306 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
21307 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
21308 should you want to disable them then add them to this list.
21309 Defaults to @samp{()}.
21312 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
21313 Path to a text file where the shared groups are defined. If this path is
21314 empty then @samp{mod_groups} does nothing. See
21315 @url{https://prosody.im/doc/modules/mod_groups}.
21316 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
21319 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
21320 Disable account creation by default, for security. See
21321 @url{https://prosody.im/doc/creating_accounts}.
21322 Defaults to @samp{#f}.
21325 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
21326 These are the SSL/TLS-related settings. Most of them are disabled so to
21327 use Prosody's defaults. If you do not completely understand these options, do
21328 not add them to your config, it is easy to lower the security of your server
21329 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
21331 Available @code{ssl-configuration} fields are:
21333 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
21334 This determines what handshake to use.
21337 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
21338 Path to your private key file.
21341 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
21342 Path to your certificate file.
21345 @deftypevr {@code{ssl-configuration} parameter} file-object capath
21346 Path to directory containing root certificates that you wish Prosody to
21347 trust when verifying the certificates of remote servers.
21348 Defaults to @samp{"/etc/ssl/certs"}.
21351 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
21352 Path to a file containing root certificates that you wish Prosody to trust.
21353 Similar to @code{capath} but with all certificates concatenated together.
21356 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
21357 A list of verification options (these mostly map to OpenSSL's
21358 @code{set_verify()} flags).
21361 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
21362 A list of general options relating to SSL/TLS. These map to OpenSSL's
21363 @code{set_options()}. For a full list of options available in LuaSec, see the
21367 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
21368 How long a chain of certificate authorities to check when looking for a
21369 trusted root certificate.
21372 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
21373 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
21374 clients, and in what order.
21377 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
21378 A path to a file containing parameters for Diffie-Hellman key exchange. You
21379 can create such a file with:
21380 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
21383 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
21384 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
21385 @samp{"secp384r1"}.
21388 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
21389 A list of ``extra'' verification options.
21392 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
21393 Password for encrypted private keys.
21398 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
21399 Whether to force all client-to-server connections to be encrypted or not.
21400 See @url{https://prosody.im/doc/modules/mod_tls}.
21401 Defaults to @samp{#f}.
21404 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
21405 Set of mechanisms that will never be offered. See
21406 @url{https://prosody.im/doc/modules/mod_saslauth}.
21407 Defaults to @samp{("DIGEST-MD5")}.
21410 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
21411 Whether to force all server-to-server connections to be encrypted or not.
21412 See @url{https://prosody.im/doc/modules/mod_tls}.
21413 Defaults to @samp{#f}.
21416 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
21417 Whether to require encryption and certificate authentication. This
21418 provides ideal security, but requires servers you communicate with to support
21419 encryption AND present valid, trusted certificates. See
21420 @url{https://prosody.im/doc/s2s#security}.
21421 Defaults to @samp{#f}.
21424 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
21425 Many servers don't support encryption or have invalid or self-signed
21426 certificates. You can list domains here that will not be required to
21427 authenticate using certificates. They will be authenticated using DNS. See
21428 @url{https://prosody.im/doc/s2s#security}.
21429 Defaults to @samp{()}.
21432 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
21433 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
21434 valid certificates for some domains by specifying a list here. See
21435 @url{https://prosody.im/doc/s2s#security}.
21436 Defaults to @samp{()}.
21439 @deftypevr {@code{prosody-configuration} parameter} string authentication
21440 Select the authentication backend to use. The default provider stores
21441 passwords in plaintext and uses Prosody's configured data storage to store the
21442 authentication data. If you do not trust your server please see
21443 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
21444 about using the hashed backend. See also
21445 @url{https://prosody.im/doc/authentication}
21446 Defaults to @samp{"internal_plain"}.
21449 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
21450 Set logging options. Advanced logging configuration is not yet supported
21451 by the Prosody service. See @url{https://prosody.im/doc/logging}.
21452 Defaults to @samp{"*syslog"}.
21455 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
21456 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
21457 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
21460 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
21461 Maximum allowed size of the HTTP body (in bytes).
21464 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
21465 Some modules expose their own URL in various ways. This URL is built
21466 from the protocol, host and port used. If Prosody sits behind a proxy, the
21467 public URL will be @code{http-external-url} instead. See
21468 @url{https://prosody.im/doc/http#external_url}.
21471 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
21472 A host in Prosody is a domain on which user accounts can be created. For
21473 example if you want your users to have addresses like
21474 @samp{"john.smith@@example.com"} then you need to add a host
21475 @samp{"example.com"}. All options in this list will apply only to this host.
21477 Note: the name @emph{virtual} host is used in configuration to avoid confusion with
21478 the actual physical host that Prosody is installed on. A single Prosody
21479 instance can serve many domains, each one defined as a VirtualHost entry in
21480 Prosody's configuration. Conversely a server that hosts a single domain would
21481 have just one VirtualHost entry.
21483 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
21485 Available @code{virtualhost-configuration} fields are:
21487 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:
21488 @deftypevr {@code{virtualhost-configuration} parameter} string domain
21489 Domain you wish Prosody to serve.
21494 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
21495 Components are extra services on a server which are available to clients,
21496 usually on a subdomain of the main server (such as
21497 @samp{"mycomponent.example.com"}). Example components might be chatroom
21498 servers, user directories, or gateways to other protocols.
21500 Internal components are implemented with Prosody-specific plugins. To add an
21501 internal component, you simply fill the hostname field, and the plugin you wish
21502 to use for the component.
21504 See @url{https://prosody.im/doc/components}.
21505 Defaults to @samp{()}.
21507 Available @code{int-component-configuration} fields are:
21509 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:
21510 @deftypevr {@code{int-component-configuration} parameter} string hostname
21511 Hostname of the component.
21514 @deftypevr {@code{int-component-configuration} parameter} string plugin
21515 Plugin you wish to use for the component.
21518 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
21519 Multi-user chat (MUC) is Prosody's module for allowing you to create
21520 hosted chatrooms/conferences for XMPP users.
21522 General information on setting up and using multi-user chatrooms can be found
21523 in the ``Chatrooms'' documentation (@url{https://prosody.im/doc/chatrooms}),
21524 which you should read if you are new to XMPP chatrooms.
21526 See also @url{https://prosody.im/doc/modules/mod_muc}.
21528 Available @code{mod-muc-configuration} fields are:
21530 @deftypevr {@code{mod-muc-configuration} parameter} string name
21531 The name to return in service discovery responses.
21532 Defaults to @samp{"Prosody Chatrooms"}.
21535 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
21536 If @samp{#t}, this will only allow admins to create new chatrooms.
21537 Otherwise anyone can create a room. The value @samp{"local"} restricts room
21538 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
21539 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
21540 restricts to service administrators only.
21541 Defaults to @samp{#f}.
21544 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
21545 Maximum number of history messages that will be sent to the member that has
21546 just joined the room.
21547 Defaults to @samp{20}.
21554 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
21555 External components use XEP-0114, which most standalone components
21556 support. To add an external component, you simply fill the hostname field. See
21557 @url{https://prosody.im/doc/components}.
21558 Defaults to @samp{()}.
21560 Available @code{ext-component-configuration} fields are:
21562 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:
21563 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
21564 Password which the component will use to log in.
21567 @deftypevr {@code{ext-component-configuration} parameter} string hostname
21568 Hostname of the component.
21573 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
21574 Port(s) Prosody listens on for component connections.
21575 Defaults to @samp{(5347)}.
21578 @deftypevr {@code{prosody-configuration} parameter} string component-interface
21579 Interface Prosody listens on for component connections.
21580 Defaults to @samp{"127.0.0.1"}.
21583 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
21584 Raw content that will be added to the configuration file.
21587 It could be that you just want to get a @code{prosody.cfg.lua}
21588 up and running. In that case, you can pass an
21589 @code{opaque-prosody-configuration} record as the value of
21590 @code{prosody-service-type}. As its name indicates, an opaque configuration
21591 does not have easy reflective capabilities.
21592 Available @code{opaque-prosody-configuration} fields are:
21594 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
21595 The prosody package.
21598 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
21599 The contents of the @code{prosody.cfg.lua} to use.
21602 For example, if your @code{prosody.cfg.lua} is just the empty
21603 string, you could instantiate a prosody service like this:
21606 (service prosody-service-type
21607 (opaque-prosody-configuration
21608 (prosody.cfg.lua "")))
21611 @c end of Prosody auto-generated documentation
21613 @subsubheading BitlBee Service
21615 @cindex IRC (Internet Relay Chat)
21616 @cindex IRC gateway
21617 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
21618 interface to a variety of messaging protocols such as XMPP.
21620 @defvr {Scheme Variable} bitlbee-service-type
21621 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
21622 gateway daemon. Its value is a @code{bitlbee-configuration} (see
21625 To have BitlBee listen on port 6667 on localhost, add this line to your
21629 (service bitlbee-service-type)
21633 @deftp {Data Type} bitlbee-configuration
21634 This is the configuration for BitlBee, with the following fields:
21637 @item @code{interface} (default: @code{"127.0.0.1"})
21638 @itemx @code{port} (default: @code{6667})
21639 Listen on the network interface corresponding to the IP address
21640 specified in @var{interface}, on @var{port}.
21642 When @var{interface} is @code{127.0.0.1}, only local clients can
21643 connect; when it is @code{0.0.0.0}, connections can come from any
21644 networking interface.
21646 @item @code{bitlbee} (default: @code{bitlbee})
21647 The BitlBee package to use.
21649 @item @code{plugins} (default: @code{'()})
21650 List of plugin packages to use---e.g., @code{bitlbee-discord}.
21652 @item @code{extra-settings} (default: @code{""})
21653 Configuration snippet added as-is to the BitlBee configuration file.
21657 @subsubheading Quassel Service
21659 @cindex IRC (Internet Relay Chat)
21660 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
21661 meaning that one or more clients can attach to and detach from the
21664 @defvr {Scheme Variable} quassel-service-type
21665 This is the service type for the @url{https://quassel-irc.org/,Quassel}
21666 IRC backend daemon. Its value is a @code{quassel-configuration}
21670 @deftp {Data Type} quassel-configuration
21671 This is the configuration for Quassel, with the following fields:
21674 @item @code{quassel} (default: @code{quassel})
21675 The Quassel package to use.
21677 @item @code{interface} (default: @code{"::,0.0.0.0"})
21678 @item @code{port} (default: @code{4242})
21679 Listen on the network interface(s) corresponding to the IPv4 or IPv6
21680 interfaces specified in the comma delimited @var{interface}, on
21683 @item @code{loglevel} (default: @code{"Info"})
21684 The level of logging desired. Accepted values are Debug, Info, Warning
21689 @node Telephony Services
21690 @subsection Telephony Services
21692 @cindex Murmur (VoIP server)
21693 @cindex VoIP server
21694 This section describes how to set up and run a Murmur server. Murmur is
21695 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
21698 @deftp {Data Type} murmur-configuration
21699 The service type for the Murmur server. An example configuration can
21703 (service murmur-service-type
21704 (murmur-configuration
21706 "Welcome to this Mumble server running on Guix!")
21707 (cert-required? #t) ;disallow text password logins
21708 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
21709 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
21712 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
21713 password with the command that is printed during the activation phase.
21715 It is recommended to register a normal Mumble user account
21716 and grant it admin or moderator rights.
21717 You can use the @code{mumble} client to
21718 login as new normal user, register yourself, and log out.
21719 For the next step login with the name @code{SuperUser} use
21720 the @code{SuperUser} password that you set previously,
21721 and grant your newly registered mumble user administrator or moderator
21722 rights and create some channels.
21724 Available @code{murmur-configuration} fields are:
21727 @item @code{package} (default: @code{mumble})
21728 Package that contains @code{bin/murmurd}.
21730 @item @code{user} (default: @code{"murmur"})
21731 User who will run the Murmur server.
21733 @item @code{group} (default: @code{"murmur"})
21734 Group of the user who will run the murmur server.
21736 @item @code{port} (default: @code{64738})
21737 Port on which the server will listen.
21739 @item @code{welcome-text} (default: @code{""})
21740 Welcome text sent to clients when they connect.
21742 @item @code{server-password} (default: @code{""})
21743 Password the clients have to enter in order to connect.
21745 @item @code{max-users} (default: @code{100})
21746 Maximum of users that can be connected to the server at once.
21748 @item @code{max-user-bandwidth} (default: @code{#f})
21749 Maximum voice traffic a user can send per second.
21751 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
21752 File name of the sqlite database.
21753 The service's user will become the owner of the directory.
21755 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
21756 File name of the log file.
21757 The service's user will become the owner of the directory.
21759 @item @code{autoban-attempts} (default: @code{10})
21760 Maximum number of logins a user can make in @code{autoban-timeframe}
21761 without getting auto banned for @code{autoban-time}.
21763 @item @code{autoban-timeframe} (default: @code{120})
21764 Timeframe for autoban in seconds.
21766 @item @code{autoban-time} (default: @code{300})
21767 Amount of time in seconds for which a client gets banned
21768 when violating the autoban limits.
21770 @item @code{opus-threshold} (default: @code{100})
21771 Percentage of clients that need to support opus
21772 before switching over to opus audio codec.
21774 @item @code{channel-nesting-limit} (default: @code{10})
21775 How deep channels can be nested at maximum.
21777 @item @code{channelname-regex} (default: @code{#f})
21778 A string in form of a Qt regular expression that channel names must conform to.
21780 @item @code{username-regex} (default: @code{#f})
21781 A string in form of a Qt regular expression that user names must conform to.
21783 @item @code{text-message-length} (default: @code{5000})
21784 Maximum size in bytes that a user can send in one text chat message.
21786 @item @code{image-message-length} (default: @code{(* 128 1024)})
21787 Maximum size in bytes that a user can send in one image message.
21789 @item @code{cert-required?} (default: @code{#f})
21790 If it is set to @code{#t} clients that use weak password authentication
21791 will not be accepted. Users must have completed the certificate wizard to join.
21793 @item @code{remember-channel?} (default: @code{#f})
21794 Should murmur remember the last channel each user was in when they disconnected
21795 and put them into the remembered channel when they rejoin.
21797 @item @code{allow-html?} (default: @code{#f})
21798 Should html be allowed in text messages, user comments, and channel descriptions.
21800 @item @code{allow-ping?} (default: @code{#f})
21801 Setting to true exposes the current user count, the maximum user count, and
21802 the server's maximum bandwidth per client to unauthenticated users. In the
21803 Mumble client, this information is shown in the Connect dialog.
21805 Disabling this setting will prevent public listing of the server.
21807 @item @code{bonjour?} (default: @code{#f})
21808 Should the server advertise itself in the local network through the bonjour protocol.
21810 @item @code{send-version?} (default: @code{#f})
21811 Should the murmur server version be exposed in ping requests.
21813 @item @code{log-days} (default: @code{31})
21814 Murmur also stores logs in the database, which are accessible via RPC.
21815 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
21816 or -1 to disable logging to the database.
21818 @item @code{obfuscate-ips?} (default: @code{#t})
21819 Should logged ips be obfuscated to protect the privacy of users.
21821 @item @code{ssl-cert} (default: @code{#f})
21822 File name of the SSL/TLS certificate used for encrypted connections.
21825 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
21827 @item @code{ssl-key} (default: @code{#f})
21828 Filepath to the ssl private key used for encrypted connections.
21830 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
21833 @item @code{ssl-dh-params} (default: @code{#f})
21834 File name of a PEM-encoded file with Diffie-Hellman parameters
21835 for the SSL/TLS encryption. Alternatively you set it to
21836 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
21837 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
21839 @item @code{ssl-ciphers} (default: @code{#f})
21840 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
21843 This option is specified using
21844 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
21845 OpenSSL cipher list notation}.
21847 It is recommended that you try your cipher string using 'openssl ciphers <string>'
21848 before setting it here, to get a feel for which cipher suites you will get.
21849 After setting this option, it is recommend that you inspect your Murmur log
21850 to ensure that Murmur is using the cipher suites that you expected it to.
21852 Note: Changing this option may impact the backwards compatibility of your
21853 Murmur server, and can remove the ability for older Mumble clients to be able
21856 @item @code{public-registration} (default: @code{#f})
21857 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
21859 You can optionally register your server in the public server list that the
21860 @code{mumble} client shows on startup.
21861 You cannot register your server if you have set a @code{server-password},
21862 or set @code{allow-ping} to @code{#f}.
21864 It might take a few hours until it shows up in the public list.
21866 @item @code{file} (default: @code{#f})
21867 Optional alternative override for this configuration.
21871 @deftp {Data Type} murmur-public-registration-configuration
21872 Configuration for public registration of a murmur service.
21876 This is a display name for your server. Not to be confused with the hostname.
21878 @item @code{password}
21879 A password to identify your registration.
21880 Subsequent updates will need the same password. Don't lose your password.
21883 This should be a @code{http://} or @code{https://} link to your web
21886 @item @code{hostname} (default: @code{#f})
21887 By default your server will be listed by its IP address.
21888 If it is set your server will be linked by this host name instead.
21894 @node Monitoring Services
21895 @subsection Monitoring Services
21897 @subsubheading Tailon Service
21899 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
21900 viewing and searching log files.
21902 The following example will configure the service with default values.
21903 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
21906 (service tailon-service-type)
21909 The following example customises more of the Tailon configuration,
21910 adding @command{sed} to the list of allowed commands.
21913 (service tailon-service-type
21914 (tailon-configuration
21916 (tailon-configuration-file
21917 (allowed-commands '("tail" "grep" "awk" "sed"))))))
21921 @deftp {Data Type} tailon-configuration
21922 Data type representing the configuration of Tailon.
21923 This type has the following parameters:
21926 @item @code{config-file} (default: @code{(tailon-configuration-file)})
21927 The configuration file to use for Tailon. This can be set to a
21928 @dfn{tailon-configuration-file} record value, or any gexp
21929 (@pxref{G-Expressions}).
21931 For example, to instead use a local file, the @code{local-file} function
21935 (service tailon-service-type
21936 (tailon-configuration
21937 (config-file (local-file "./my-tailon.conf"))))
21940 @item @code{package} (default: @code{tailon})
21941 The tailon package to use.
21946 @deftp {Data Type} tailon-configuration-file
21947 Data type representing the configuration options for Tailon.
21948 This type has the following parameters:
21951 @item @code{files} (default: @code{(list "/var/log")})
21952 List of files to display. The list can include strings for a single file
21953 or directory, or a list, where the first item is the name of a
21954 subsection, and the remaining items are the files or directories in that
21957 @item @code{bind} (default: @code{"localhost:8080"})
21958 Address and port to which Tailon should bind on.
21960 @item @code{relative-root} (default: @code{#f})
21961 URL path to use for Tailon, set to @code{#f} to not use a path.
21963 @item @code{allow-transfers?} (default: @code{#t})
21964 Allow downloading the log files in the web interface.
21966 @item @code{follow-names?} (default: @code{#t})
21967 Allow tailing of not-yet existent files.
21969 @item @code{tail-lines} (default: @code{200})
21970 Number of lines to read initially from each file.
21972 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
21973 Commands to allow running. By default, @code{sed} is disabled.
21975 @item @code{debug?} (default: @code{#f})
21976 Set @code{debug?} to @code{#t} to show debug messages.
21978 @item @code{wrap-lines} (default: @code{#t})
21979 Initial line wrapping state in the web interface. Set to @code{#t} to
21980 initially wrap lines (the default), or to @code{#f} to initially not
21983 @item @code{http-auth} (default: @code{#f})
21984 HTTP authentication type to use. Set to @code{#f} to disable
21985 authentication (the default). Supported values are @code{"digest"} or
21988 @item @code{users} (default: @code{#f})
21989 If HTTP authentication is enabled (see @code{http-auth}), access will be
21990 restricted to the credentials provided here. To configure users, use a
21991 list of pairs, where the first element of the pair is the username, and
21992 the 2nd element of the pair is the password.
21995 (tailon-configuration-file
21996 (http-auth "basic")
21997 (users '(("user1" . "password1")
21998 ("user2" . "password2"))))
22005 @subsubheading Darkstat Service
22007 Darkstat is a packet sniffer that captures network traffic, calculates
22008 statistics about usage, and serves reports over HTTP.
22010 @defvar {Scheme Variable} darkstat-service-type
22011 This is the service type for the
22012 @uref{https://unix4lyfe.org/darkstat/, darkstat}
22013 service, its value must be a @code{darkstat-configuration} record as in
22017 (service darkstat-service-type
22018 (darkstat-configuration
22019 (interface "eno1")))
22023 @deftp {Data Type} darkstat-configuration
22024 Data type representing the configuration of @command{darkstat}.
22027 @item @code{package} (default: @code{darkstat})
22028 The darkstat package to use.
22030 @item @code{interface}
22031 Capture traffic on the specified network interface.
22033 @item @code{port} (default: @code{"667"})
22034 Bind the web interface to the specified port.
22036 @item @code{bind-address} (default: @code{"127.0.0.1"})
22037 Bind the web interface to the specified address.
22039 @item @code{base} (default: @code{"/"})
22040 Specify the path of the base URL. This can be useful if
22041 @command{darkstat} is accessed via a reverse proxy.
22046 @subsubheading Prometheus Node Exporter Service
22048 @cindex prometheus-node-exporter
22049 The Prometheus ``node exporter'' makes hardware and operating system statistics
22050 provided by the Linux kernel available for the Prometheus monitoring system.
22051 This service should be deployed on all physical nodes and virtual machines,
22052 where monitoring these statistics is desirable.
22054 @defvar {Scheme variable} prometheus-node-exporter-service-type
22055 This is the service type for the
22056 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
22057 service, its value must be a @code{prometheus-node-exporter-configuration}.
22060 (service prometheus-node-exporter-service-type)
22064 @deftp {Data Type} prometheus-node-exporter-configuration
22065 Data type representing the configuration of @command{node_exporter}.
22068 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
22069 The prometheus-node-exporter package to use.
22071 @item @code{web-listen-address} (default: @code{":9100"})
22072 Bind the web interface to the specified address.
22074 @item @code{textfile-directory} (default: @code{"/var/lib/prometheus/node-exporter"})
22075 This directory can be used to export metrics specific to this machine.
22076 Files containing metrics in the text format, with the filename ending in
22077 @code{.prom} should be placed in this directory.
22079 @item @code{extra-options} (default: @code{'()})
22080 Extra options to pass to the Prometheus node exporter.
22085 @subsubheading Zabbix server
22086 @cindex zabbix zabbix-server
22087 Zabbix provides monitoring metrics, among others network utilization, CPU load
22088 and disk space consumption:
22091 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
22092 @item Auto-discovery of servers and network devices and interfaces.
22093 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
22094 @item Distributed monitoring with centralized web administration.
22095 @item Native high performance agents.
22096 @item SLA, and ITIL KPI metrics on reporting.
22097 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
22098 @item Remote command execution through Zabbix proxies.
22101 @c %start of fragment
22103 Available @code{zabbix-server-configuration} fields are:
22105 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
22106 The zabbix-server package.
22110 @deftypevr {@code{zabbix-server-configuration} parameter} string user
22111 User who will run the Zabbix server.
22113 Defaults to @samp{"zabbix"}.
22117 @deftypevr {@code{zabbix-server-configuration} parameter} group group
22118 Group who will run the Zabbix server.
22120 Defaults to @samp{"zabbix"}.
22124 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
22125 Database host name.
22127 Defaults to @samp{"127.0.0.1"}.
22131 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
22134 Defaults to @samp{"zabbix"}.
22138 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
22141 Defaults to @samp{"zabbix"}.
22145 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
22146 Database password. Please, use @code{include-files} with
22147 @code{DBPassword=SECRET} inside a specified file instead.
22149 Defaults to @samp{""}.
22153 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
22156 Defaults to @samp{5432}.
22160 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
22161 Specifies where log messages are written to:
22165 @code{system} - syslog.
22168 @code{file} - file specified with @code{log-file} parameter.
22171 @code{console} - standard output.
22175 Defaults to @samp{""}.
22179 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
22180 Log file name for @code{log-type} @code{file} parameter.
22182 Defaults to @samp{"/var/log/zabbix/server.log"}.
22186 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
22189 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
22193 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
22194 The location of certificate authority (CA) files for SSL server
22195 certificate verification.
22197 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
22201 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
22202 Location of SSL client certificates.
22204 Defaults to @samp{"/etc/ssl/certs"}.
22208 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
22209 Extra options will be appended to Zabbix server configuration file.
22211 Defaults to @samp{""}.
22215 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
22216 You may include individual files or all files in a directory in the
22217 configuration file.
22219 Defaults to @samp{()}.
22223 @c %end of fragment
22225 @subsubheading Zabbix agent
22226 @cindex zabbix zabbix-agent
22228 Zabbix agent gathers information for Zabbix server.
22230 @c %start of fragment
22232 Available @code{zabbix-agent-configuration} fields are:
22234 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
22235 The zabbix-agent package.
22239 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
22240 User who will run the Zabbix agent.
22242 Defaults to @samp{"zabbix"}.
22246 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
22247 Group who will run the Zabbix agent.
22249 Defaults to @samp{"zabbix"}.
22253 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
22254 Unique, case sensitive hostname which is required for active checks and
22255 must match hostname as configured on the server.
22257 Defaults to @samp{""}.
22261 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
22262 Specifies where log messages are written to:
22266 @code{system} - syslog.
22269 @code{file} - file specified with @code{log-file} parameter.
22272 @code{console} - standard output.
22276 Defaults to @samp{""}.
22280 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
22281 Log file name for @code{log-type} @code{file} parameter.
22283 Defaults to @samp{"/var/log/zabbix/agent.log"}.
22287 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
22290 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
22294 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
22295 List of IP addresses, optionally in CIDR notation, or hostnames of
22296 Zabbix servers and Zabbix proxies. Incoming connections will be
22297 accepted only from the hosts listed here.
22299 Defaults to @samp{("127.0.0.1")}.
22303 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
22304 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
22305 proxies for active checks. If port is not specified, default port is
22306 used. If this parameter is not specified, active checks are disabled.
22308 Defaults to @samp{("127.0.0.1")}.
22312 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
22313 Extra options will be appended to Zabbix server configuration file.
22315 Defaults to @samp{""}.
22319 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
22320 You may include individual files or all files in a directory in the
22321 configuration file.
22323 Defaults to @samp{()}.
22327 @c %end of fragment
22329 @subsubheading Zabbix front-end
22330 @cindex zabbix zabbix-front-end
22332 This service provides a WEB interface to Zabbix server.
22334 @c %start of fragment
22336 Available @code{zabbix-front-end-configuration} fields are:
22338 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
22339 NGINX configuration.
22343 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
22344 Database host name.
22346 Defaults to @samp{"localhost"}.
22350 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
22353 Defaults to @samp{5432}.
22357 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
22360 Defaults to @samp{"zabbix"}.
22364 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
22367 Defaults to @samp{"zabbix"}.
22371 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
22372 Database password. Please, use @code{db-secret-file} instead.
22374 Defaults to @samp{""}.
22378 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
22379 Secret file containing the credentials for the Zabbix front-end. The value
22380 must be a local file name, not a G-expression. You are expected to create
22381 this file manually. Its contents will be copied into @file{zabbix.conf.php}
22382 as the value of @code{$DB['PASSWORD']}.
22384 Defaults to @samp{""}.
22388 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
22389 Zabbix server hostname.
22391 Defaults to @samp{"localhost"}.
22395 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
22396 Zabbix server port.
22398 Defaults to @samp{10051}.
22403 @c %end of fragment
22405 @node Kerberos Services
22406 @subsection Kerberos Services
22409 The @code{(gnu services kerberos)} module provides services relating to
22410 the authentication protocol @dfn{Kerberos}.
22412 @subsubheading Krb5 Service
22414 Programs using a Kerberos client library normally
22415 expect a configuration file in @file{/etc/krb5.conf}.
22416 This service generates such a file from a definition provided in the
22417 operating system declaration.
22418 It does not cause any daemon to be started.
22420 No ``keytab'' files are provided by this service---you must explicitly create them.
22421 This service is known to work with the MIT client library, @code{mit-krb5}.
22422 Other implementations have not been tested.
22424 @defvr {Scheme Variable} krb5-service-type
22425 A service type for Kerberos 5 clients.
22429 Here is an example of its use:
22431 (service krb5-service-type
22432 (krb5-configuration
22433 (default-realm "EXAMPLE.COM")
22434 (allow-weak-crypto? #t)
22437 (name "EXAMPLE.COM")
22438 (admin-server "groucho.example.com")
22439 (kdc "karl.example.com"))
22442 (admin-server "kerb-admin.argrx.edu")
22443 (kdc "keys.argrx.edu"))))))
22447 This example provides a Kerberos@tie{}5 client configuration which:
22449 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
22450 of which have distinct administration servers and key distribution centers;
22451 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
22452 specified by clients;
22453 @item Accepts services which only support encryption types known to be weak.
22456 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
22457 Only the most commonly used ones are described here.
22458 For a full list, and more detailed explanation of each, see the MIT
22459 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
22463 @deftp {Data Type} krb5-realm
22464 @cindex realm, kerberos
22467 This field is a string identifying the name of the realm.
22468 A common convention is to use the fully qualified DNS name of your organization,
22469 converted to upper case.
22471 @item @code{admin-server}
22472 This field is a string identifying the host where the administration server is
22476 This field is a string identifying the key distribution center
22481 @deftp {Data Type} krb5-configuration
22484 @item @code{allow-weak-crypto?} (default: @code{#f})
22485 If this flag is @code{#t} then services which only offer encryption algorithms
22486 known to be weak will be accepted.
22488 @item @code{default-realm} (default: @code{#f})
22489 This field should be a string identifying the default Kerberos
22490 realm for the client.
22491 You should set this field to the name of your Kerberos realm.
22492 If this value is @code{#f}
22493 then a realm must be specified with every Kerberos principal when invoking programs
22494 such as @command{kinit}.
22496 @item @code{realms}
22497 This should be a non-empty list of @code{krb5-realm} objects, which clients may
22499 Normally, one of them will have a @code{name} field matching the @code{default-realm}
22505 @subsubheading PAM krb5 Service
22508 The @code{pam-krb5} service allows for login authentication and password
22509 management via Kerberos.
22510 You will need this service if you want PAM enabled applications to authenticate
22511 users using Kerberos.
22513 @defvr {Scheme Variable} pam-krb5-service-type
22514 A service type for the Kerberos 5 PAM module.
22517 @deftp {Data Type} pam-krb5-configuration
22518 Data type representing the configuration of the Kerberos 5 PAM module.
22519 This type has the following parameters:
22521 @item @code{pam-krb5} (default: @code{pam-krb5})
22522 The pam-krb5 package to use.
22524 @item @code{minimum-uid} (default: @code{1000})
22525 The smallest user ID for which Kerberos authentications should be attempted.
22526 Local accounts with lower values will silently fail to authenticate.
22531 @node LDAP Services
22532 @subsection LDAP Services
22534 @cindex nslcd, LDAP service
22536 The @code{(gnu services authentication)} module provides the
22537 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
22538 server. In addition to configuring the service itself, you may want to add
22539 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
22540 Switch} for detailed information.
22542 Here is a simple operating system declaration with a default configuration of
22543 the @code{nslcd-service-type} and a Name Service Switch configuration that
22544 consults the @code{ldap} name service last:
22547 (use-service-modules authentication)
22548 (use-modules (gnu system nss))
22554 (service nslcd-service-type)
22555 (service dhcp-client-service-type)
22557 (name-service-switch
22558 (let ((services (list (name-service (name "db"))
22559 (name-service (name "files"))
22560 (name-service (name "ldap")))))
22561 (name-service-switch
22562 (inherit %mdns-host-lookup-nss)
22563 (password services)
22566 (netgroup services)
22567 (gshadow services)))))
22570 @c %start of generated documentation for nslcd-configuration
22572 Available @code{nslcd-configuration} fields are:
22574 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
22575 The @code{nss-pam-ldapd} package to use.
22579 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
22580 The number of threads to start that can handle requests and perform LDAP
22581 queries. Each thread opens a separate connection to the LDAP server.
22582 The default is to start 5 threads.
22584 Defaults to @samp{disabled}.
22588 @deftypevr {@code{nslcd-configuration} parameter} string uid
22589 This specifies the user id with which the daemon should be run.
22591 Defaults to @samp{"nslcd"}.
22595 @deftypevr {@code{nslcd-configuration} parameter} string gid
22596 This specifies the group id with which the daemon should be run.
22598 Defaults to @samp{"nslcd"}.
22602 @deftypevr {@code{nslcd-configuration} parameter} log-option log
22603 This option controls the way logging is done via a list containing
22604 SCHEME and LEVEL. The SCHEME argument may either be the symbols
22605 @samp{none} or @samp{syslog}, or an absolute file name. The LEVEL
22606 argument is optional and specifies the log level. The log level may be
22607 one of the following symbols: @samp{crit}, @samp{error}, @samp{warning},
22608 @samp{notice}, @samp{info} or @samp{debug}. All messages with the
22609 specified log level or higher are logged.
22611 Defaults to @samp{("/var/log/nslcd" info)}.
22615 @deftypevr {@code{nslcd-configuration} parameter} list uri
22616 The list of LDAP server URIs. Normally, only the first server will be
22617 used with the following servers as fall-back.
22619 Defaults to @samp{("ldap://localhost:389/")}.
22623 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
22624 The version of the LDAP protocol to use. The default is to use the
22625 maximum version supported by the LDAP library.
22627 Defaults to @samp{disabled}.
22631 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
22632 Specifies the distinguished name with which to bind to the directory
22633 server for lookups. The default is to bind anonymously.
22635 Defaults to @samp{disabled}.
22639 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
22640 Specifies the credentials with which to bind. This option is only
22641 applicable when used with binddn.
22643 Defaults to @samp{disabled}.
22647 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
22648 Specifies the distinguished name to use when the root user tries to
22649 modify a user's password using the PAM module.
22651 Defaults to @samp{disabled}.
22655 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
22656 Specifies the credentials with which to bind if the root user tries to
22657 change a user's password. This option is only applicable when used with
22660 Defaults to @samp{disabled}.
22664 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
22665 Specifies the SASL mechanism to be used when performing SASL
22668 Defaults to @samp{disabled}.
22672 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
22673 Specifies the SASL realm to be used when performing SASL authentication.
22675 Defaults to @samp{disabled}.
22679 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
22680 Specifies the authentication identity to be used when performing SASL
22683 Defaults to @samp{disabled}.
22687 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
22688 Specifies the authorization identity to be used when performing SASL
22691 Defaults to @samp{disabled}.
22695 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
22696 Determines whether the LDAP server host name should be canonicalised. If
22697 this is enabled the LDAP library will do a reverse host name lookup. By
22698 default, it is left up to the LDAP library whether this check is
22701 Defaults to @samp{disabled}.
22705 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
22706 Set the name for the GSS-API Kerberos credentials cache.
22708 Defaults to @samp{disabled}.
22712 @deftypevr {@code{nslcd-configuration} parameter} string base
22713 The directory search base.
22715 Defaults to @samp{"dc=example,dc=com"}.
22719 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
22720 Specifies the search scope (subtree, onelevel, base or children). The
22721 default scope is subtree; base scope is almost never useful for name
22722 service lookups; children scope is not supported on all servers.
22724 Defaults to @samp{(subtree)}.
22728 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
22729 Specifies the policy for dereferencing aliases. The default policy is
22730 to never dereference aliases.
22732 Defaults to @samp{disabled}.
22736 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
22737 Specifies whether automatic referral chasing should be enabled. The
22738 default behaviour is to chase referrals.
22740 Defaults to @samp{disabled}.
22744 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
22745 This option allows for custom attributes to be looked up instead of the
22746 default RFC 2307 attributes. It is a list of maps, each consisting of
22747 the name of a map, the RFC 2307 attribute to match and the query
22748 expression for the attribute as it is available in the directory.
22750 Defaults to @samp{()}.
22754 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
22755 A list of filters consisting of the name of a map to which the filter
22756 applies and an LDAP search filter expression.
22758 Defaults to @samp{()}.
22762 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
22763 Specifies the time limit in seconds to use when connecting to the
22764 directory server. The default value is 10 seconds.
22766 Defaults to @samp{disabled}.
22770 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
22771 Specifies the time limit (in seconds) to wait for a response from the
22772 LDAP server. A value of zero, which is the default, is to wait
22773 indefinitely for searches to be completed.
22775 Defaults to @samp{disabled}.
22779 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
22780 Specifies the period if inactivity (in seconds) after which the con‐
22781 nection to the LDAP server will be closed. The default is not to time
22784 Defaults to @samp{disabled}.
22788 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
22789 Specifies the number of seconds to sleep when connecting to all LDAP
22790 servers fails. By default one second is waited between the first
22791 failure and the first retry.
22793 Defaults to @samp{disabled}.
22797 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
22798 Specifies the time after which the LDAP server is considered to be
22799 permanently unavailable. Once this time is reached retries will be done
22800 only once per this time period. The default value is 10 seconds.
22802 Defaults to @samp{disabled}.
22806 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
22807 Specifies whether to use SSL/TLS or not (the default is not to). If
22808 'start-tls is specified then StartTLS is used rather than raw LDAP over
22811 Defaults to @samp{disabled}.
22815 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
22816 Specifies what checks to perform on a server-supplied certificate. The
22817 meaning of the values is described in the ldap.conf(5) manual page.
22819 Defaults to @samp{disabled}.
22823 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
22824 Specifies the directory containing X.509 certificates for peer authen‐
22825 tication. This parameter is ignored when using GnuTLS.
22827 Defaults to @samp{disabled}.
22831 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
22832 Specifies the path to the X.509 certificate for peer authentication.
22834 Defaults to @samp{disabled}.
22838 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
22839 Specifies the path to an entropy source. This parameter is ignored when
22842 Defaults to @samp{disabled}.
22846 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
22847 Specifies the ciphers to use for TLS as a string.
22849 Defaults to @samp{disabled}.
22853 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
22854 Specifies the path to the file containing the local certificate for
22855 client TLS authentication.
22857 Defaults to @samp{disabled}.
22861 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
22862 Specifies the path to the file containing the private key for client TLS
22865 Defaults to @samp{disabled}.
22869 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
22870 Set this to a number greater than 0 to request paged results from the
22871 LDAP server in accordance with RFC2696. The default (0) is to not
22872 request paged results.
22874 Defaults to @samp{disabled}.
22878 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
22879 This option prevents group membership lookups through LDAP for the
22880 specified users. Alternatively, the value 'all-local may be used. With
22881 that value nslcd builds a full list of non-LDAP users on startup.
22883 Defaults to @samp{disabled}.
22887 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
22888 This option ensures that LDAP users with a numeric user id lower than
22889 the specified value are ignored.
22891 Defaults to @samp{disabled}.
22895 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
22896 This option specifies an offset that is added to all LDAP numeric user
22897 ids. This can be used to avoid user id collisions with local users.
22899 Defaults to @samp{disabled}.
22903 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
22904 This option specifies an offset that is added to all LDAP numeric group
22905 ids. This can be used to avoid user id collisions with local groups.
22907 Defaults to @samp{disabled}.
22911 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
22912 If this option is set, the member attribute of a group may point to
22913 another group. Members of nested groups are also returned in the higher
22914 level group and parent groups are returned when finding groups for a
22915 specific user. The default is not to perform extra searches for nested
22918 Defaults to @samp{disabled}.
22922 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
22923 If this option is set, the group member list is not retrieved when
22924 looking up groups. Lookups for finding which groups a user belongs to
22925 will remain functional so the user will likely still get the correct
22926 groups assigned on login.
22928 Defaults to @samp{disabled}.
22932 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
22933 If this option is set, functions which cause all user/group entries to
22934 be loaded from the directory will not succeed in doing so. This can
22935 dramatically reduce LDAP server load in situations where there are a
22936 great number of users and/or groups. This option is not recommended for
22937 most configurations.
22939 Defaults to @samp{disabled}.
22943 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
22944 This option can be used to specify how user and group names are verified
22945 within the system. This pattern is used to check all user and group
22946 names that are requested and returned from LDAP.
22948 Defaults to @samp{disabled}.
22952 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
22953 This specifies whether or not to perform searches using case-insensitive
22954 matching. Enabling this could open up the system to authorization
22955 bypass vulnerabilities and introduce nscd cache poisoning
22956 vulnerabilities which allow denial of service.
22958 Defaults to @samp{disabled}.
22962 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
22963 This option specifies whether password policy controls are requested and
22964 handled from the LDAP server when performing user authentication.
22966 Defaults to @samp{disabled}.
22970 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
22971 By default nslcd performs an LDAP search with the user's credentials
22972 after BIND (authentication) to ensure that the BIND operation was
22973 successful. The default search is a simple check to see if the user's
22974 DN exists. A search filter can be specified that will be used instead.
22975 It should return at least one entry.
22977 Defaults to @samp{disabled}.
22981 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
22982 This option allows flexible fine tuning of the authorisation check that
22983 should be performed. The search filter specified is executed and if any
22984 entries match, access is granted, otherwise access is denied.
22986 Defaults to @samp{disabled}.
22990 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
22991 If this option is set password modification using pam_ldap will be
22992 denied and the specified message will be presented to the user instead.
22993 The message can be used to direct the user to an alternative means of
22994 changing their password.
22996 Defaults to @samp{disabled}.
23000 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
23001 List of pam service names for which LDAP authentication should suffice.
23003 Defaults to @samp{()}.
23007 @c %end of generated documentation for nslcd-configuration
23011 @subsection Web Services
23016 The @code{(gnu services web)} module provides the Apache HTTP Server,
23017 the nginx web server, and also a fastcgi wrapper daemon.
23019 @subsubheading Apache HTTP Server
23021 @deffn {Scheme Variable} httpd-service-type
23022 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
23023 (@dfn{httpd}). The value for this service type is a
23024 @code{httpd-configuration} record.
23026 A simple example configuration is given below.
23029 (service httpd-service-type
23030 (httpd-configuration
23033 (server-name "www.example.com")
23034 (document-root "/srv/http/www.example.com")))))
23037 Other services can also extend the @code{httpd-service-type} to add to
23041 (simple-service 'www.example.com-server httpd-service-type
23045 (list (string-join '("ServerName www.example.com"
23046 "DocumentRoot /srv/http/www.example.com")
23051 The details for the @code{httpd-configuration}, @code{httpd-module},
23052 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
23055 @deffn {Data Type} httpd-configuration
23056 This data type represents the configuration for the httpd service.
23059 @item @code{package} (default: @code{httpd})
23060 The httpd package to use.
23062 @item @code{pid-file} (default: @code{"/var/run/httpd"})
23063 The pid file used by the shepherd-service.
23065 @item @code{config} (default: @code{(httpd-config-file)})
23066 The configuration file to use with the httpd service. The default value
23067 is a @code{httpd-config-file} record, but this can also be a different
23068 G-expression that generates a file, for example a @code{plain-file}. A
23069 file outside of the store can also be specified through a string.
23074 @deffn {Data Type} httpd-module
23075 This data type represents a module for the httpd service.
23079 The name of the module.
23082 The file for the module. This can be relative to the httpd package being
23083 used, the absolute location of a file, or a G-expression for a file
23084 within the store, for example @code{(file-append mod-wsgi
23085 "/modules/mod_wsgi.so")}.
23090 @defvr {Scheme Variable} %default-httpd-modules
23091 A default list of @code{httpd-module} objects.
23094 @deffn {Data Type} httpd-config-file
23095 This data type represents a configuration file for the httpd service.
23098 @item @code{modules} (default: @code{%default-httpd-modules})
23099 The modules to load. Additional modules can be added here, or loaded by
23100 additional configuration.
23102 For example, in order to handle requests for PHP files, you can use Apache’s
23103 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
23106 (service httpd-service-type
23107 (httpd-configuration
23112 (name "proxy_module")
23113 (file "modules/mod_proxy.so"))
23115 (name "proxy_fcgi_module")
23116 (file "modules/mod_proxy_fcgi.so"))
23117 %default-httpd-modules))
23118 (extra-config (list "\
23119 <FilesMatch \\.php$>
23120 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
23121 </FilesMatch>"))))))
23122 (service php-fpm-service-type
23123 (php-fpm-configuration
23124 (socket "/var/run/php-fpm.sock")
23125 (socket-group "httpd")))
23128 @item @code{server-root} (default: @code{httpd})
23129 The @code{ServerRoot} in the configuration file, defaults to the httpd
23130 package. Directives including @code{Include} and @code{LoadModule} are
23131 taken as relative to the server root.
23133 @item @code{server-name} (default: @code{#f})
23134 The @code{ServerName} in the configuration file, used to specify the
23135 request scheme, hostname and port that the server uses to identify
23138 This doesn't need to be set in the server config, and can be specified
23139 in virtual hosts. The default is @code{#f} to not specify a
23142 @item @code{document-root} (default: @code{"/srv/http"})
23143 The @code{DocumentRoot} from which files will be served.
23145 @item @code{listen} (default: @code{'("80")})
23146 The list of values for the @code{Listen} directives in the config
23147 file. The value should be a list of strings, when each string can
23148 specify the port number to listen on, and optionally the IP address and
23151 @item @code{pid-file} (default: @code{"/var/run/httpd"})
23152 The @code{PidFile} to use. This should match the @code{pid-file} set in
23153 the @code{httpd-configuration} so that the Shepherd service is
23154 configured correctly.
23156 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
23157 The @code{ErrorLog} to which the server will log errors.
23159 @item @code{user} (default: @code{"httpd"})
23160 The @code{User} which the server will answer requests as.
23162 @item @code{group} (default: @code{"httpd"})
23163 The @code{Group} which the server will answer requests as.
23165 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
23166 A flat list of strings and G-expressions which will be added to the end
23167 of the configuration file.
23169 Any values which the service is extended with will be appended to this
23175 @deffn {Data Type} httpd-virtualhost
23176 This data type represents a virtualhost configuration block for the httpd service.
23178 These should be added to the extra-config for the httpd-service.
23181 (simple-service 'www.example.com-server httpd-service-type
23185 (list (string-join '("ServerName www.example.com"
23186 "DocumentRoot /srv/http/www.example.com")
23191 @item @code{addresses-and-ports}
23192 The addresses and ports for the @code{VirtualHost} directive.
23194 @item @code{contents}
23195 The contents of the @code{VirtualHost} directive, this should be a list
23196 of strings and G-expressions.
23201 @subsubheading NGINX
23203 @deffn {Scheme Variable} nginx-service-type
23204 Service type for the @uref{https://nginx.org/,NGinx} web server. The
23205 value for this service type is a @code{<nginx-configuration>} record.
23207 A simple example configuration is given below.
23210 (service nginx-service-type
23211 (nginx-configuration
23213 (list (nginx-server-configuration
23214 (server-name '("www.example.com"))
23215 (root "/srv/http/www.example.com"))))))
23218 In addition to adding server blocks to the service configuration
23219 directly, this service can be extended by other services to add server
23220 blocks, as in this example:
23223 (simple-service 'my-extra-server nginx-service-type
23224 (list (nginx-server-configuration
23225 (root "/srv/http/extra-website")
23226 (try-files (list "$uri" "$uri/index.html")))))
23230 At startup, @command{nginx} has not yet read its configuration file, so
23231 it uses a default file to log error messages. If it fails to load its
23232 configuration file, that is where error messages are logged. After the
23233 configuration file is loaded, the default error log file changes as per
23234 configuration. In our case, startup error messages can be found in
23235 @file{/var/run/nginx/logs/error.log}, and after configuration in
23236 @file{/var/log/nginx/error.log}. The second location can be changed
23237 with the @var{log-directory} configuration option.
23239 @deffn {Data Type} nginx-configuration
23240 This data type represents the configuration for NGinx. Some
23241 configuration can be done through this and the other provided record
23242 types, or alternatively, a config file can be provided.
23245 @item @code{nginx} (default: @code{nginx})
23246 The nginx package to use.
23248 @item @code{log-directory} (default: @code{"/var/log/nginx"})
23249 The directory to which NGinx will write log files.
23251 @item @code{run-directory} (default: @code{"/var/run/nginx"})
23252 The directory in which NGinx will create a pid file, and write temporary
23255 @item @code{server-blocks} (default: @code{'()})
23256 A list of @dfn{server blocks} to create in the generated configuration
23257 file, the elements should be of type
23258 @code{<nginx-server-configuration>}.
23260 The following example would setup NGinx to serve @code{www.example.com}
23261 from the @code{/srv/http/www.example.com} directory, without using
23264 (service nginx-service-type
23265 (nginx-configuration
23267 (list (nginx-server-configuration
23268 (server-name '("www.example.com"))
23269 (root "/srv/http/www.example.com"))))))
23272 @item @code{upstream-blocks} (default: @code{'()})
23273 A list of @dfn{upstream blocks} to create in the generated configuration
23274 file, the elements should be of type
23275 @code{<nginx-upstream-configuration>}.
23277 Configuring upstreams through the @code{upstream-blocks} can be useful
23278 when combined with @code{locations} in the
23279 @code{<nginx-server-configuration>} records. The following example
23280 creates a server configuration with one location configuration, that
23281 will proxy requests to a upstream configuration, which will handle
23282 requests with two servers.
23287 (nginx-configuration
23289 (list (nginx-server-configuration
23290 (server-name '("www.example.com"))
23291 (root "/srv/http/www.example.com")
23294 (nginx-location-configuration
23296 (body '("proxy_pass http://server-proxy;"))))))))
23298 (list (nginx-upstream-configuration
23299 (name "server-proxy")
23300 (servers (list "server1.example.com"
23301 "server2.example.com")))))))
23304 @item @code{file} (default: @code{#f})
23305 If a configuration @var{file} is provided, this will be used, rather than
23306 generating a configuration file from the provided @code{log-directory},
23307 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
23308 proper operation, these arguments should match what is in @var{file} to ensure
23309 that the directories are created when the service is activated.
23311 This can be useful if you have an existing configuration file, or it's
23312 not possible to do what is required through the other parts of the
23313 nginx-configuration record.
23315 @item @code{server-names-hash-bucket-size} (default: @code{#f})
23316 Bucket size for the server names hash tables, defaults to @code{#f} to
23317 use the size of the processors cache line.
23319 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
23320 Maximum bucket size for the server names hash tables.
23322 @item @code{modules} (default: @code{'()})
23323 List of nginx dynamic modules to load. This should be a list of file
23324 names of loadable modules, as in this example:
23329 (file-append nginx-accept-language-module "\
23330 /etc/nginx/modules/ngx_http_accept_language_module.so")
23331 (file-append nginx-lua-module "\
23332 /etc/nginx/modules/ngx_http_lua_module.so")))
23335 @item @code{lua-package-path} (default: @code{'()})
23336 List of nginx lua packages to load. This should be a list of package
23337 names of loadable lua modules, as in this example:
23340 (lua-package-path (list lua-resty-core
23347 @item @code{lua-package-cpath} (default: @code{'()})
23348 List of nginx lua C packages to load. This should be a list of package
23349 names of loadable lua C modules, as in this example:
23352 (lua-package-cpath (list lua-resty-signal))
23355 @item @code{global-directives} (default: @code{'((events . ()))})
23356 Association list of global directives for the top level of the nginx
23357 configuration. Values may themselves be association lists.
23361 `((worker_processes . 16)
23363 (events . ((worker_connections . 1024)))))
23366 @item @code{extra-content} (default: @code{""})
23367 Extra content for the @code{http} block. Should be string or a string
23368 valued G-expression.
23373 @deftp {Data Type} nginx-server-configuration
23374 Data type representing the configuration of an nginx server block.
23375 This type has the following parameters:
23378 @item @code{listen} (default: @code{'("80" "443 ssl")})
23379 Each @code{listen} directive sets the address and port for IP, or the
23380 path for a UNIX-domain socket on which the server will accept requests.
23381 Both address and port, or only address or only port can be specified.
23382 An address may also be a hostname, for example:
23385 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
23388 @item @code{server-name} (default: @code{(list 'default)})
23389 A list of server names this server represents. @code{'default} represents the
23390 default server for connections matching no other server.
23392 @item @code{root} (default: @code{"/srv/http"})
23393 Root of the website nginx will serve.
23395 @item @code{locations} (default: @code{'()})
23396 A list of @dfn{nginx-location-configuration} or
23397 @dfn{nginx-named-location-configuration} records to use within this
23400 @item @code{index} (default: @code{(list "index.html")})
23401 Index files to look for when clients ask for a directory. If it cannot be found,
23402 Nginx will send the list of files in the directory.
23404 @item @code{try-files} (default: @code{'()})
23405 A list of files whose existence is checked in the specified order.
23406 @code{nginx} will use the first file it finds to process the request.
23408 @item @code{ssl-certificate} (default: @code{#f})
23409 Where to find the certificate for secure connections. Set it to @code{#f} if
23410 you don't have a certificate or you don't want to use HTTPS.
23412 @item @code{ssl-certificate-key} (default: @code{#f})
23413 Where to find the private key for secure connections. Set it to @code{#f} if
23414 you don't have a key or you don't want to use HTTPS.
23416 @item @code{server-tokens?} (default: @code{#f})
23417 Whether the server should add its configuration to response.
23419 @item @code{raw-content} (default: @code{'()})
23420 A list of raw lines added to the server block.
23425 @deftp {Data Type} nginx-upstream-configuration
23426 Data type representing the configuration of an nginx @code{upstream}
23427 block. This type has the following parameters:
23431 Name for this group of servers.
23433 @item @code{servers}
23434 Specify the addresses of the servers in the group. The address can be
23435 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
23436 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
23437 prefix @samp{unix:}. For addresses using an IP address or domain name,
23438 the default port is 80, and a different port can be specified
23444 @deftp {Data Type} nginx-location-configuration
23445 Data type representing the configuration of an nginx @code{location}
23446 block. This type has the following parameters:
23450 URI which this location block matches.
23452 @anchor{nginx-location-configuration body}
23454 Body of the location block, specified as a list of strings. This can contain
23456 configuration directives. For example, to pass requests to a upstream
23457 server group defined using an @code{nginx-upstream-configuration} block,
23458 the following directive would be specified in the body @samp{(list "proxy_pass
23459 http://upstream-name;")}.
23464 @deftp {Data Type} nginx-named-location-configuration
23465 Data type representing the configuration of an nginx named location
23466 block. Named location blocks are used for request redirection, and not
23467 used for regular request processing. This type has the following
23472 Name to identify this location block.
23475 @xref{nginx-location-configuration body}, as the body for named location
23476 blocks can be used in a similar way to the
23477 @code{nginx-location-configuration body}. One restriction is that the
23478 body of a named location block cannot contain location blocks.
23483 @subsubheading Varnish Cache
23485 Varnish is a fast cache server that sits in between web applications
23486 and end users. It proxies requests from clients and caches the
23487 accessed URLs such that multiple requests for the same resource only
23488 creates one request to the back-end.
23490 @defvr {Scheme Variable} varnish-service-type
23491 Service type for the Varnish daemon.
23494 @deftp {Data Type} varnish-configuration
23495 Data type representing the @code{varnish} service configuration.
23496 This type has the following parameters:
23499 @item @code{package} (default: @code{varnish})
23500 The Varnish package to use.
23502 @item @code{name} (default: @code{"default"})
23503 A name for this Varnish instance. Varnish will create a directory in
23504 @file{/var/varnish/} with this name and keep temporary files there. If
23505 the name starts with a forward slash, it is interpreted as an absolute
23508 Pass the @code{-n} argument to other Varnish programs to connect to the
23509 named instance, e.g.@: @command{varnishncsa -n default}.
23511 @item @code{backend} (default: @code{"localhost:8080"})
23512 The backend to use. This option has no effect if @code{vcl} is set.
23514 @item @code{vcl} (default: #f)
23515 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
23516 is @code{#f}, Varnish will proxy @code{backend} using the default
23517 configuration. Otherwise this must be a file-like object with valid
23520 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
23521 For example, to mirror @url{https://www.gnu.org,www.gnu.org} with VCL you
23522 can do something along these lines:
23525 (define %gnu-mirror
23526 (plain-file "gnu.vcl"
23528 backend gnu @{ .host = \"www.gnu.org\"; @}"))
23532 (services (cons (service varnish-service-type
23533 (varnish-configuration
23535 (vcl %gnu-mirror)))
23539 The configuration of an already running Varnish instance can be inspected
23540 and changed using the @command{varnishadm} program.
23542 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
23543 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
23544 comprehensive documentation on Varnish and its configuration language.
23546 @item @code{listen} (default: @code{'("localhost:80")})
23547 List of addresses Varnish will listen on.
23549 @item @code{storage} (default: @code{'("malloc,128m")})
23550 List of storage backends that will be available in VCL.
23552 @item @code{parameters} (default: @code{'()})
23553 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
23555 @item @code{extra-options} (default: @code{'()})
23556 Additional arguments to pass to the @command{varnishd} process.
23561 @subsubheading Patchwork
23563 Patchwork is a patch tracking system. It can collect patches sent to a
23564 mailing list, and display them in a web interface.
23566 @defvr {Scheme Variable} patchwork-service-type
23567 Service type for Patchwork.
23570 The following example is an example of a minimal service for Patchwork, for
23571 the @code{patchwork.example.com} domain.
23574 (service patchwork-service-type
23575 (patchwork-configuration
23576 (domain "patchwork.example.com")
23578 (patchwork-settings-module
23579 (allowed-hosts (list domain))
23580 (default-from-email "patchwork@@patchwork.example.com")))
23581 (getmail-retriever-config
23582 (getmail-retriever-configuration
23583 (type "SimpleIMAPSSLRetriever")
23584 (server "imap.example.com")
23586 (username "patchwork")
23588 (list (file-append coreutils "/bin/cat")
23589 "/etc/getmail-patchwork-imap-password"))
23591 '((mailboxes . ("Patches"))))))))
23595 There are three records for configuring the Patchwork service. The
23596 @code{<patchwork-configuration>} relates to the configuration for Patchwork
23597 within the HTTPD service.
23599 The @code{settings-module} field within the @code{<patchwork-configuration>}
23600 record can be populated with the @code{<patchwork-settings-module>} record,
23601 which describes a settings module that is generated within the Guix store.
23603 For the @code{database-configuration} field within the
23604 @code{<patchwork-settings-module>}, the
23605 @code{<patchwork-database-configuration>} must be used.
23607 @deftp {Data Type} patchwork-configuration
23608 Data type representing the Patchwork service configuration. This type has the
23609 following parameters:
23612 @item @code{patchwork} (default: @code{patchwork})
23613 The Patchwork package to use.
23615 @item @code{domain}
23616 The domain to use for Patchwork, this is used in the HTTPD service virtual
23619 @item @code{settings-module}
23620 The settings module to use for Patchwork. As a Django application, Patchwork
23621 is configured with a Python module containing the settings. This can either be
23622 an instance of the @code{<patchwork-settings-module>} record, any other record
23623 that represents the settings in the store, or a directory outside of the
23626 @item @code{static-path} (default: @code{"/static/"})
23627 The path under which the HTTPD service should serve the static files.
23629 @item @code{getmail-retriever-config}
23630 The getmail-retriever-configuration record value to use with
23631 Patchwork. Getmail will be configured with this value, the messages will be
23632 delivered to Patchwork.
23637 @deftp {Data Type} patchwork-settings-module
23638 Data type representing a settings module for Patchwork. Some of these
23639 settings relate directly to Patchwork, but others relate to Django, the web
23640 framework used by Patchwork, or the Django Rest Framework library. This type
23641 has the following parameters:
23644 @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
23645 The database connection settings used for Patchwork. See the
23646 @code{<patchwork-database-configuration>} record type for more information.
23648 @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
23649 Patchwork, as a Django web application uses a secret key for cryptographically
23650 signing values. This file should contain a unique unpredictable value.
23652 If this file does not exist, it will be created and populated with a random
23653 value by the patchwork-setup shepherd service.
23655 This setting relates to Django.
23657 @item @code{allowed-hosts}
23658 A list of valid hosts for this Patchwork service. This should at least include
23659 the domain specified in the @code{<patchwork-configuration>} record.
23661 This is a Django setting.
23663 @item @code{default-from-email}
23664 The email address from which Patchwork should send email by default.
23666 This is a Patchwork setting.
23668 @item @code{static-url} (default: @code{#f})
23669 The URL to use when serving static assets. It can be part of a URL, or a full
23670 URL, but must end in a @code{/}.
23672 If the default value is used, the @code{static-path} value from the
23673 @code{<patchwork-configuration>} record will be used.
23675 This is a Django setting.
23677 @item @code{admins} (default: @code{'()})
23678 Email addresses to send the details of errors that occur. Each value should
23679 be a list containing two elements, the name and then the email address.
23681 This is a Django setting.
23683 @item @code{debug?} (default: @code{#f})
23684 Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
23685 messages will be shown.
23687 This is a Django setting.
23689 @item @code{enable-rest-api?} (default: @code{#t})
23690 Whether to enable the Patchwork REST API.
23692 This is a Patchwork setting.
23694 @item @code{enable-xmlrpc?} (default: @code{#t})
23695 Whether to enable the XML RPC API.
23697 This is a Patchwork setting.
23699 @item @code{force-https-links?} (default: @code{#t})
23700 Whether to use HTTPS links on Patchwork pages.
23702 This is a Patchwork setting.
23704 @item @code{extra-settings} (default: @code{""})
23705 Extra code to place at the end of the Patchwork settings module.
23710 @deftp {Data Type} patchwork-database-configuration
23711 Data type representing the database configuration for Patchwork.
23714 @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
23715 The database engine to use.
23717 @item @code{name} (default: @code{"patchwork"})
23718 The name of the database to use.
23720 @item @code{user} (default: @code{"httpd"})
23721 The user to connect to the database as.
23723 @item @code{password} (default: @code{""})
23724 The password to use when connecting to the database.
23726 @item @code{host} (default: @code{""})
23727 The host to make the database connection to.
23729 @item @code{port} (default: @code{""})
23730 The port on which to connect to the database.
23735 @subsubheading Mumi
23737 @cindex Mumi, Debbugs Web interface
23738 @cindex Debbugs, Mumi Web interface
23739 @uref{https://git.elephly.net/gitweb.cgi?p=software/mumi.git, Mumi} is a
23740 Web interface to the Debbugs bug tracker, by default for
23741 @uref{https://bugs.gnu.org, the GNU instance}. Mumi is a Web server,
23742 but it also fetches and indexes mail retrieved from Debbugs.
23744 @defvr {Scheme Variable} mumi-service-type
23745 This is the service type for Mumi.
23748 @deftp {Data Type} mumi-configuration
23749 Data type representing the Mumi service configuration. This type has the
23753 @item @code{mumi} (default: @code{mumi})
23754 The Mumi package to use.
23756 @item @code{mailer?} (default: @code{#true})
23757 Whether to enable or disable the mailer component.
23759 @item @code{mumi-configuration-sender}
23760 The email address used as the sender for comments.
23762 @item @code{mumi-configuration-smtp}
23763 A URI to configure the SMTP settings for Mailutils. This could be
23764 something like @code{sendmail:///path/to/bin/msmtp} or any other URI
23765 supported by Mailutils. @xref{SMTP Mailboxes, SMTP Mailboxes,,
23766 mailutils, GNU@tie{}Mailutils}.
23772 @subsubheading FastCGI
23775 FastCGI is an interface between the front-end and the back-end of a web
23776 service. It is a somewhat legacy facility; new web services should
23777 generally just talk HTTP between the front-end and the back-end.
23778 However there are a number of back-end services such as PHP or the
23779 optimized HTTP Git repository access that use FastCGI, so we have
23780 support for it in Guix.
23782 To use FastCGI, you configure the front-end web server (e.g., nginx) to
23783 dispatch some subset of its requests to the fastcgi backend, which
23784 listens on a local TCP or UNIX socket. There is an intermediary
23785 @code{fcgiwrap} program that sits between the actual backend process and
23786 the web server. The front-end indicates which backend program to run,
23787 passing that information to the @code{fcgiwrap} process.
23789 @defvr {Scheme Variable} fcgiwrap-service-type
23790 A service type for the @code{fcgiwrap} FastCGI proxy.
23793 @deftp {Data Type} fcgiwrap-configuration
23794 Data type representing the configuration of the @code{fcgiwrap} service.
23795 This type has the following parameters:
23797 @item @code{package} (default: @code{fcgiwrap})
23798 The fcgiwrap package to use.
23800 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
23801 The socket on which the @code{fcgiwrap} process should listen, as a
23802 string. Valid @var{socket} values include
23803 @code{unix:@var{/path/to/unix/socket}},
23804 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
23805 @code{tcp6:[@var{ipv6_addr}]:port}.
23807 @item @code{user} (default: @code{fcgiwrap})
23808 @itemx @code{group} (default: @code{fcgiwrap})
23809 The user and group names, as strings, under which to run the
23810 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
23811 the user asks for the specific user or group names @code{fcgiwrap} that
23812 the corresponding user and/or group is present on the system.
23814 It is possible to configure a FastCGI-backed web service to pass HTTP
23815 authentication information from the front-end to the back-end, and to
23816 allow @code{fcgiwrap} to run the back-end process as a corresponding
23817 local user. To enable this capability on the back-end, run
23818 @code{fcgiwrap} as the @code{root} user and group. Note that this
23819 capability also has to be configured on the front-end as well.
23824 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
23825 with some additional features useful for sites of any size.
23827 These features include:
23829 @item Adaptive process spawning
23830 @item Basic statistics (similar to Apache's mod_status)
23831 @item Advanced process management with graceful stop/start
23832 @item Ability to start workers with different uid/gid/chroot/environment
23833 and different php.ini (replaces safe_mode)
23834 @item Stdout & stderr logging
23835 @item Emergency restart in case of accidental opcode cache destruction
23836 @item Accelerated upload support
23837 @item Support for a "slowlog"
23838 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
23839 a special function to finish request & flush all data while continuing to do
23840 something time-consuming (video converting, stats processing, etc.)
23842 ...@: and much more.
23844 @defvr {Scheme Variable} php-fpm-service-type
23845 A Service type for @code{php-fpm}.
23848 @deftp {Data Type} php-fpm-configuration
23849 Data Type for php-fpm service configuration.
23851 @item @code{php} (default: @code{php})
23852 The php package to use.
23853 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
23854 The address on which to accept FastCGI requests. Valid syntaxes are:
23856 @item @code{"ip.add.re.ss:port"}
23857 Listen on a TCP socket to a specific address on a specific port.
23858 @item @code{"port"}
23859 Listen on a TCP socket to all addresses on a specific port.
23860 @item @code{"/path/to/unix/socket"}
23861 Listen on a unix socket.
23864 @item @code{user} (default: @code{php-fpm})
23865 User who will own the php worker processes.
23866 @item @code{group} (default: @code{php-fpm})
23867 Group of the worker processes.
23868 @item @code{socket-user} (default: @code{php-fpm})
23869 User who can speak to the php-fpm socket.
23870 @item @code{socket-group} (default: @code{nginx})
23871 Group that can speak to the php-fpm socket.
23872 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
23873 The process id of the php-fpm process is written to this file
23874 once the service has started.
23875 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
23876 Log for the php-fpm master process.
23877 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
23878 Detailed settings for the php-fpm process manager.
23881 @item @code{<php-fpm-dynamic-process-manager-configuration>}
23882 @item @code{<php-fpm-static-process-manager-configuration>}
23883 @item @code{<php-fpm-on-demand-process-manager-configuration>}
23885 @item @code{display-errors} (default @code{#f})
23886 Determines whether php errors and warning should be sent to clients
23887 and displayed in their browsers.
23888 This is useful for local php development, but a security risk for public sites,
23889 as error messages can reveal passwords and personal data.
23890 @item @code{timezone} (default @code{#f})
23891 Specifies @code{php_admin_value[date.timezone]} parameter.
23892 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
23893 This file will log the @code{stderr} outputs of php worker processes.
23894 Can be set to @code{#f} to disable logging.
23895 @item @code{file} (default @code{#f})
23896 An optional override of the whole configuration.
23897 You can use the @code{mixed-text-file} function or an absolute filepath for it.
23898 @item @code{php-ini-file} (default @code{#f})
23899 An optional override of the default php settings.
23900 It may be any ``file-like'' object (@pxref{G-Expressions, file-like objects}).
23901 You can use the @code{mixed-text-file} function or an absolute filepath for it.
23903 For local development it is useful to set a higher timeout and memory
23904 limit for spawned php processes. This be accomplished with the
23905 following operating system configuration snippet:
23907 (define %local-php-ini
23908 (plain-file "php.ini"
23910 max_execution_time = 1800"))
23914 (services (cons (service php-fpm-service-type
23915 (php-fpm-configuration
23916 (php-ini-file %local-php-ini)))
23920 Consult the @url{https://www.php.net/manual/en/ini.core.php,core php.ini
23921 directives} for comprehensive documentation on the acceptable
23922 @file{php.ini} directives.
23926 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
23927 Data Type for the @code{dynamic} php-fpm process manager. With the
23928 @code{dynamic} process manager, spare worker processes are kept around
23929 based on it's configured limits.
23931 @item @code{max-children} (default: @code{5})
23932 Maximum of worker processes.
23933 @item @code{start-servers} (default: @code{2})
23934 How many worker processes should be started on start-up.
23935 @item @code{min-spare-servers} (default: @code{1})
23936 How many spare worker processes should be kept around at minimum.
23937 @item @code{max-spare-servers} (default: @code{3})
23938 How many spare worker processes should be kept around at maximum.
23942 @deftp {Data type} php-fpm-static-process-manager-configuration
23943 Data Type for the @code{static} php-fpm process manager. With the
23944 @code{static} process manager, an unchanging number of worker processes
23947 @item @code{max-children} (default: @code{5})
23948 Maximum of worker processes.
23952 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
23953 Data Type for the @code{on-demand} php-fpm process manager. With the
23954 @code{on-demand} process manager, worker processes are only created as
23957 @item @code{max-children} (default: @code{5})
23958 Maximum of worker processes.
23959 @item @code{process-idle-timeout} (default: @code{10})
23960 The time in seconds after which a process with no requests is killed.
23965 @deffn {Scheme Procedure} nginx-php-location @
23966 [#:nginx-package nginx] @
23967 [socket (string-append "/var/run/php" @
23968 (version-major (package-version php)) @
23970 A helper function to quickly add php to an @code{nginx-server-configuration}.
23973 A simple services setup for nginx with php can look like this:
23975 (services (cons* (service dhcp-client-service-type)
23976 (service php-fpm-service-type)
23977 (service nginx-service-type
23978 (nginx-server-configuration
23979 (server-name '("example.com"))
23980 (root "/srv/http/")
23982 (list (nginx-php-location)))
23984 (ssl-certificate #f)
23985 (ssl-certificate-key #f)))
23989 @cindex cat-avatar-generator
23990 The cat avatar generator is a simple service to demonstrate the use of php-fpm
23991 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
23992 the hash of a user's email address.
23994 @deffn {Scheme Procedure} cat-avatar-generator-service @
23995 [#:cache-dir "/var/cache/cat-avatar-generator"] @
23996 [#:package cat-avatar-generator] @
23997 [#:configuration (nginx-server-configuration)]
23998 Returns an nginx-server-configuration that inherits @code{configuration}. It
23999 extends the nginx configuration to add a server block that serves @code{package},
24000 a version of cat-avatar-generator. During execution, cat-avatar-generator will
24001 be able to use @code{cache-dir} as its cache directory.
24004 A simple setup for cat-avatar-generator can look like this:
24006 (services (cons* (cat-avatar-generator-service
24008 (nginx-server-configuration
24009 (server-name '("example.com"))))
24014 @subsubheading Hpcguix-web
24016 @cindex hpcguix-web
24017 The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
24018 program is a customizable web interface to browse Guix packages,
24019 initially designed for users of high-performance computing (HPC)
24022 @defvr {Scheme Variable} hpcguix-web-service-type
24023 The service type for @code{hpcguix-web}.
24026 @deftp {Data Type} hpcguix-web-configuration
24027 Data type for the hpcguix-web service configuration.
24031 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
24032 configuration. The main items available in this spec are:
24035 @item @code{title-prefix} (default: @code{"hpcguix | "})
24036 The page title prefix.
24038 @item @code{guix-command} (default: @code{"guix"})
24039 The @command{guix} command.
24041 @item @code{package-filter-proc} (default: @code{(const #t)})
24042 A procedure specifying how to filter packages that are displayed.
24044 @item @code{package-page-extension-proc} (default: @code{(const '())})
24045 Extension package for @code{hpcguix-web}.
24047 @item @code{menu} (default: @code{'()})
24048 Additional entry in page @code{menu}.
24050 @item @code{channels} (default: @code{%default-channels})
24051 List of channels from which the package list is built (@pxref{Channels}).
24053 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
24054 The expiration time, in seconds, after which the package list is rebuilt from
24055 the latest instances of the given channels.
24058 See the hpcguix-web repository for a
24059 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
24062 @item @code{package} (default: @code{hpcguix-web})
24063 The hpcguix-web package to use.
24067 A typical hpcguix-web service declaration looks like this:
24070 (service hpcguix-web-service-type
24071 (hpcguix-web-configuration
24073 #~(define site-config
24074 (hpcweb-configuration
24075 (title-prefix "Guix-HPC - ")
24076 (menu '(("/about" "ABOUT"))))))))
24080 The hpcguix-web service periodically updates the package list it publishes by
24081 pulling channels from Git. To that end, it needs to access X.509 certificates
24082 so that it can authenticate Git servers when communicating over HTTPS, and it
24083 assumes that @file{/etc/ssl/certs} contains those certificates.
24085 Thus, make sure to add @code{nss-certs} or another certificate package to the
24086 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
24087 more information on X.509 certificates.
24090 @subsubheading gmnisrv
24093 The @uref{https://git.sr.ht/~sircmpwn/gmnisrv, gmnisrv} program is a
24094 simple @uref{https://gemini.circumlunar.space/, Gemini} protocol server.
24096 @deffn {Scheme Variable} gmnisrv-service-type
24097 This is the type of the gmnisrv service, whose value should be a
24098 @code{gmnisrv-configuration} object, as in this example:
24101 (service gmnisrv-service-type
24102 (gmnisrv-configuration
24103 (config-file (local-file "./my-gmnisrv.ini"))))
24107 @deftp {Data Type} gmnisrv-configuration
24108 Data type representing the configuration of gmnisrv.
24111 @item @code{package} (default: @var{gmnisrv})
24112 Package object of the gmnisrv server.
24114 @item @code{config-file} (default: @code{%default-gmnisrv-config-file})
24115 File-like object of the gmnisrv configuration file to use. The default
24116 configuration listens on port 1965 and serves files from
24117 @file{/srv/gemini}. Certificates are stored in
24118 @file{/var/lib/gemini/certs}. For more information, run @command{man
24119 gmnisrv} and @command{man gmnisrv.ini}.
24124 @node Certificate Services
24125 @subsection Certificate Services
24128 @cindex HTTP, HTTPS
24129 @cindex Let's Encrypt
24130 @cindex TLS certificates
24131 The @code{(gnu services certbot)} module provides a service to
24132 automatically obtain a valid TLS certificate from the Let's Encrypt
24133 certificate authority. These certificates can then be used to serve
24134 content securely over HTTPS or other TLS-based protocols, with the
24135 knowledge that the client will be able to verify the server's
24138 @url{https://letsencrypt.org/, Let's Encrypt} provides the
24139 @code{certbot} tool to automate the certification process. This tool
24140 first securely generates a key on the server. It then makes a request
24141 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
24142 checks that the request originates from the host in question by using a
24143 challenge-response protocol, requiring the server to provide its
24144 response over HTTP. If that protocol completes successfully, the CA
24145 signs the key, resulting in a certificate. That certificate is valid
24146 for a limited period of time, and therefore to continue to provide TLS
24147 services, the server needs to periodically ask the CA to renew its
24150 The certbot service automates this process: the initial key
24151 generation, the initial certification request to the Let's Encrypt
24152 service, the web server challenge/response integration, writing the
24153 certificate to disk, the automated periodic renewals, and the deployment
24154 tasks associated with the renewal (e.g.@: reloading services, copying keys
24155 with different permissions).
24157 Certbot is run twice a day, at a random minute within the hour. It
24158 won't do anything until your certificates are due for renewal or
24159 revoked, but running it regularly would give your service a chance of
24160 staying online in case a Let's Encrypt-initiated revocation happened for
24163 By using this service, you agree to the ACME Subscriber Agreement, which
24164 can be found there:
24165 @url{https://acme-v01.api.letsencrypt.org/directory}.
24167 @defvr {Scheme Variable} certbot-service-type
24168 A service type for the @code{certbot} Let's Encrypt client. Its value
24169 must be a @code{certbot-configuration} record as in this example:
24172 (define %nginx-deploy-hook
24174 "nginx-deploy-hook"
24175 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
24176 (kill pid SIGHUP))))
24178 (service certbot-service-type
24179 (certbot-configuration
24180 (email "foo@@example.net")
24183 (certificate-configuration
24184 (domains '("example.net" "www.example.net"))
24185 (deploy-hook %nginx-deploy-hook))
24186 (certificate-configuration
24187 (domains '("bar.example.net")))))))
24190 See below for details about @code{certbot-configuration}.
24193 @deftp {Data Type} certbot-configuration
24194 Data type representing the configuration of the @code{certbot} service.
24195 This type has the following parameters:
24198 @item @code{package} (default: @code{certbot})
24199 The certbot package to use.
24201 @item @code{webroot} (default: @code{/var/www})
24202 The directory from which to serve the Let's Encrypt challenge/response
24205 @item @code{certificates} (default: @code{()})
24206 A list of @code{certificates-configuration}s for which to generate
24207 certificates and request signatures. Each certificate has a @code{name}
24208 and several @code{domains}.
24210 @item @code{email} (default: @code{#f})
24211 Optional email address used for registration and recovery contact.
24212 Setting this is encouraged as it allows you to receive important
24213 notifications about the account and issued certificates.
24215 @item @code{server} (default: @code{#f})
24216 Optional URL of ACME server. Setting this overrides certbot's default,
24217 which is the Let's Encrypt server.
24219 @item @code{rsa-key-size} (default: @code{2048})
24220 Size of the RSA key.
24222 @item @code{default-location} (default: @i{see below})
24223 The default @code{nginx-location-configuration}. Because @code{certbot}
24224 needs to be able to serve challenges and responses, it needs to be able
24225 to run a web server. It does so by extending the @code{nginx} web
24226 service with an @code{nginx-server-configuration} listening on the
24227 @var{domains} on port 80, and which has a
24228 @code{nginx-location-configuration} for the @code{/.well-known/} URI
24229 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
24230 these nginx configuration data types.
24232 Requests to other URL paths will be matched by the
24233 @code{default-location}, which if present is added to all
24234 @code{nginx-server-configuration}s.
24236 By default, the @code{default-location} will issue a redirect from
24237 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
24238 you to define what to serve on your site via @code{https}.
24240 Pass @code{#f} to not issue a default location.
24244 @deftp {Data Type} certificate-configuration
24245 Data type representing the configuration of a certificate.
24246 This type has the following parameters:
24249 @item @code{name} (default: @i{see below})
24250 This name is used by Certbot for housekeeping and in file paths; it
24251 doesn't affect the content of the certificate itself. To see
24252 certificate names, run @code{certbot certificates}.
24254 Its default is the first provided domain.
24256 @item @code{domains} (default: @code{()})
24257 The first domain provided will be the subject CN of the certificate, and
24258 all domains will be Subject Alternative Names on the certificate.
24260 @item @code{challenge} (default: @code{#f})
24261 The challenge type that has to be run by certbot. If @code{#f} is specified,
24262 default to the HTTP challenge. If a value is specified, defaults to the
24263 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
24264 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}),
24265 and gives Let's Encrypt permission to log the public IP address of the
24266 requesting machine.
24268 @item @code{authentication-hook} (default: @code{#f})
24269 Command to be run in a shell once for each certificate challenge to be
24270 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
24271 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
24272 contains the validation string and @code{$CERTBOT_TOKEN} contains the
24273 file name of the resource requested when performing an HTTP-01 challenge.
24275 @item @code{cleanup-hook} (default: @code{#f})
24276 Command to be run in a shell once for each certificate challenge that
24277 have been answered by the @code{auth-hook}. For this command, the shell
24278 variables available in the @code{auth-hook} script are still available, and
24279 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
24280 of the @code{auth-hook} script.
24282 @item @code{deploy-hook} (default: @code{#f})
24283 Command to be run in a shell once for each successfully issued
24284 certificate. For this command, the shell variable
24285 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
24286 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
24287 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
24288 contain a space-delimited list of renewed certificate domains (for
24289 example, @samp{"example.com www.example.com"}.
24294 For each @code{certificate-configuration}, the certificate is saved to
24295 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
24296 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
24298 @subsection DNS Services
24299 @cindex DNS (domain name system)
24300 @cindex domain name system (DNS)
24302 The @code{(gnu services dns)} module provides services related to the
24303 @dfn{domain name system} (DNS). It provides a server service for hosting
24304 an @emph{authoritative} DNS server for multiple zones, slave or master.
24305 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
24306 caching and forwarding DNS server for the LAN, which uses
24307 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
24309 @subsubheading Knot Service
24311 An example configuration of an authoritative server for two zones, one master
24315 (define-zone-entries example.org.zone
24316 ;; Name TTL Class Type Data
24317 ("@@" "" "IN" "A" "127.0.0.1")
24318 ("@@" "" "IN" "NS" "ns")
24319 ("ns" "" "IN" "A" "127.0.0.1"))
24321 (define master-zone
24322 (knot-zone-configuration
24323 (domain "example.org")
24325 (origin "example.org")
24326 (entries example.org.zone)))))
24329 (knot-zone-configuration
24330 (domain "plop.org")
24331 (dnssec-policy "default")
24332 (master (list "plop-master"))))
24334 (define plop-master
24335 (knot-remote-configuration
24337 (address (list "208.76.58.171"))))
24341 (services (cons* (service knot-service-type
24342 (knot-configuration
24343 (remotes (list plop-master))
24344 (zones (list master-zone slave-zone))))
24349 @deffn {Scheme Variable} knot-service-type
24350 This is the type for the Knot DNS server.
24352 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
24353 zones, that is to say domain names you would buy from a registrar. This server
24354 is not a resolver, meaning that it can only resolve names for which it is
24355 authoritative. This server can be configured to serve zones as a master server
24356 or a slave server as a per-zone basis. Slave zones will get their data from
24357 masters, and will serve it as an authoritative server. From the point of view
24358 of a resolver, there is no difference between master and slave.
24360 The following data types are used to configure the Knot DNS server:
24363 @deftp {Data Type} knot-key-configuration
24364 Data type representing a key.
24365 This type has the following parameters:
24368 @item @code{id} (default: @code{""})
24369 An identifier for other configuration fields to refer to this key. IDs must
24370 be unique and must not be empty.
24372 @item @code{algorithm} (default: @code{#f})
24373 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
24374 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
24375 and @code{'hmac-sha512}.
24377 @item @code{secret} (default: @code{""})
24378 The secret key itself.
24383 @deftp {Data Type} knot-acl-configuration
24384 Data type representing an Access Control List (ACL) configuration.
24385 This type has the following parameters:
24388 @item @code{id} (default: @code{""})
24389 An identifier for other configuration fields to refer to this key. IDs must be
24390 unique and must not be empty.
24392 @item @code{address} (default: @code{'()})
24393 An ordered list of IP addresses, network subnets, or network ranges represented
24394 with strings. The query must match one of them. Empty value means that
24395 address match is not required.
24397 @item @code{key} (default: @code{'()})
24398 An ordered list of references to keys represented with strings. The string
24399 must match a key ID defined in a @code{knot-key-configuration}. No key means
24400 that a key is not require to match that ACL.
24402 @item @code{action} (default: @code{'()})
24403 An ordered list of actions that are permitted or forbidden by this ACL. Possible
24404 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
24405 and @code{'update}.
24407 @item @code{deny?} (default: @code{#f})
24408 When true, the ACL defines restrictions. Listed actions are forbidden. When
24409 false, listed actions are allowed.
24414 @deftp {Data Type} zone-entry
24415 Data type representing a record entry in a zone file.
24416 This type has the following parameters:
24419 @item @code{name} (default: @code{"@@"})
24420 The name of the record. @code{"@@"} refers to the origin of the zone. Names
24421 are relative to the origin of the zone. For example, in the @code{example.org}
24422 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
24423 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
24424 refers to @code{ns.example.org}.
24426 @item @code{ttl} (default: @code{""})
24427 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
24429 @item @code{class} (default: @code{"IN"})
24430 The class of the record. Knot currently supports only @code{"IN"} and
24431 partially @code{"CH"}.
24433 @item @code{type} (default: @code{"A"})
24434 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
24435 address), NS (Name Server) and MX (Mail eXchange). Many other types are
24438 @item @code{data} (default: @code{""})
24439 The data contained in the record. For instance an IP address associated with
24440 an A record, or a domain name associated with an NS record. Remember that
24441 domain names are relative to the origin unless they end with a dot.
24446 @deftp {Data Type} zone-file
24447 Data type representing the content of a zone file.
24448 This type has the following parameters:
24451 @item @code{entries} (default: @code{'()})
24452 The list of entries. The SOA record is taken care of, so you don't need to
24453 put it in the list of entries. This list should probably contain an entry
24454 for your primary authoritative DNS server. Other than using a list of entries
24455 directly, you can use @code{define-zone-entries} to define a object containing
24456 the list of entries more easily, that you can later pass to the @code{entries}
24457 field of the @code{zone-file}.
24459 @item @code{origin} (default: @code{""})
24460 The name of your zone. This parameter cannot be empty.
24462 @item @code{ns} (default: @code{"ns"})
24463 The domain of your primary authoritative DNS server. The name is relative to
24464 the origin, unless it ends with a dot. It is mandatory that this primary
24465 DNS server corresponds to an NS record in the zone and that it is associated
24466 to an IP address in the list of entries.
24468 @item @code{mail} (default: @code{"hostmaster"})
24469 An email address people can contact you at, as the owner of the zone. This
24470 is translated as @code{<mail>@@<origin>}.
24472 @item @code{serial} (default: @code{1})
24473 The serial number of the zone. As this is used to keep track of changes by
24474 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
24475 Always increment it when you make a change in your zone.
24477 @item @code{refresh} (default: @code{(* 2 24 3600)})
24478 The frequency at which slaves will do a zone transfer. This value is a number
24479 of seconds. It can be computed by multiplications or with
24480 @code{(string->duration)}.
24482 @item @code{retry} (default: @code{(* 15 60)})
24483 The period after which a slave will retry to contact its master when it fails
24484 to do so a first time.
24486 @item @code{expiry} (default: @code{(* 14 24 3600)})
24487 Default TTL of records. Existing records are considered correct for at most
24488 this amount of time. After this period, resolvers will invalidate their cache
24489 and check again that it still exists.
24491 @item @code{nx} (default: @code{3600})
24492 Default TTL of inexistant records. This delay is usually short because you want
24493 your new domains to reach everyone quickly.
24498 @deftp {Data Type} knot-remote-configuration
24499 Data type representing a remote configuration.
24500 This type has the following parameters:
24503 @item @code{id} (default: @code{""})
24504 An identifier for other configuration fields to refer to this remote. IDs must
24505 be unique and must not be empty.
24507 @item @code{address} (default: @code{'()})
24508 An ordered list of destination IP addresses. Addresses are tried in sequence.
24509 An optional port can be given with the @@ separator. For instance:
24510 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
24512 @item @code{via} (default: @code{'()})
24513 An ordered list of source IP addresses. An empty list will have Knot choose
24514 an appropriate source IP. An optional port can be given with the @@ separator.
24515 The default is to choose at random.
24517 @item @code{key} (default: @code{#f})
24518 A reference to a key, that is a string containing the identifier of a key
24519 defined in a @code{knot-key-configuration} field.
24524 @deftp {Data Type} knot-keystore-configuration
24525 Data type representing a keystore to hold dnssec keys.
24526 This type has the following parameters:
24529 @item @code{id} (default: @code{""})
24530 The id of the keystore. It must not be empty.
24532 @item @code{backend} (default: @code{'pem})
24533 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
24535 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
24536 The configuration string of the backend. An example for the PKCS#11 is:
24537 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
24538 For the pem backend, the string represents a path in the file system.
24543 @deftp {Data Type} knot-policy-configuration
24544 Data type representing a dnssec policy. Knot DNS is able to automatically
24545 sign your zones. It can either generate and manage your keys automatically or
24546 use keys that you generate.
24548 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
24549 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
24550 zone. In order to be trusted, the KSK needs to be present in the parent zone
24551 (usually a top-level domain). If your registrar supports dnssec, you will
24552 have to send them your KSK's hash so they can add a DS record in their zone.
24553 This is not automated and need to be done each time you change your KSK.
24555 The policy also defines the lifetime of keys. Usually, ZSK can be changed
24556 easily and use weaker cryptographic functions (they use lower parameters) in
24557 order to sign records quickly, so they are changed often. The KSK however
24558 requires manual interaction with the registrar, so they are changed less often
24559 and use stronger parameters because they sign only one record.
24561 This type has the following parameters:
24564 @item @code{id} (default: @code{""})
24565 The id of the policy. It must not be empty.
24567 @item @code{keystore} (default: @code{"default"})
24568 A reference to a keystore, that is a string containing the identifier of a
24569 keystore defined in a @code{knot-keystore-configuration} field. The
24570 @code{"default"} identifier means the default keystore (a kasp database that
24571 was setup by this service).
24573 @item @code{manual?} (default: @code{#f})
24574 Whether the key management is manual or automatic.
24576 @item @code{single-type-signing?} (default: @code{#f})
24577 When @code{#t}, use the Single-Type Signing Scheme.
24579 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
24580 An algorithm of signing keys and issued signatures.
24582 @item @code{ksk-size} (default: @code{256})
24583 The length of the KSK. Note that this value is correct for the default
24584 algorithm, but would be unsecure for other algorithms.
24586 @item @code{zsk-size} (default: @code{256})
24587 The length of the ZSK. Note that this value is correct for the default
24588 algorithm, but would be unsecure for other algorithms.
24590 @item @code{dnskey-ttl} (default: @code{'default})
24591 The TTL value for DNSKEY records added into zone apex. The special
24592 @code{'default} value means same as the zone SOA TTL.
24594 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
24595 The period between ZSK publication and the next rollover initiation.
24597 @item @code{propagation-delay} (default: @code{(* 24 3600)})
24598 An extra delay added for each key rollover step. This value should be high
24599 enough to cover propagation of data from the master server to all slaves.
24601 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
24602 A validity period of newly issued signatures.
24604 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
24605 A period how long before a signature expiration the signature will be refreshed.
24607 @item @code{nsec3?} (default: @code{#f})
24608 When @code{#t}, NSEC3 will be used instead of NSEC.
24610 @item @code{nsec3-iterations} (default: @code{5})
24611 The number of additional times the hashing is performed.
24613 @item @code{nsec3-salt-length} (default: @code{8})
24614 The length of a salt field in octets, which is appended to the original owner
24615 name before hashing.
24617 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
24618 The validity period of newly issued salt field.
24623 @deftp {Data Type} knot-zone-configuration
24624 Data type representing a zone served by Knot.
24625 This type has the following parameters:
24628 @item @code{domain} (default: @code{""})
24629 The domain served by this configuration. It must not be empty.
24631 @item @code{file} (default: @code{""})
24632 The file where this zone is saved. This parameter is ignored by master zones.
24633 Empty means default location that depends on the domain name.
24635 @item @code{zone} (default: @code{(zone-file)})
24636 The content of the zone file. This parameter is ignored by slave zones. It
24637 must contain a zone-file record.
24639 @item @code{master} (default: @code{'()})
24640 A list of master remotes. When empty, this zone is a master. When set, this
24641 zone is a slave. This is a list of remotes identifiers.
24643 @item @code{ddns-master} (default: @code{#f})
24644 The main master. When empty, it defaults to the first master in the list of
24647 @item @code{notify} (default: @code{'()})
24648 A list of slave remote identifiers.
24650 @item @code{acl} (default: @code{'()})
24651 A list of acl identifiers.
24653 @item @code{semantic-checks?} (default: @code{#f})
24654 When set, this adds more semantic checks to the zone.
24656 @item @code{disable-any?} (default: @code{#f})
24657 When set, this forbids queries of the ANY type.
24659 @item @code{zonefile-sync} (default: @code{0})
24660 The delay between a modification in memory and on disk. 0 means immediate
24663 @item @code{zonefile-load} (default: @code{#f})
24664 The way the zone file contents are applied during zone load. Possible values
24668 @item @code{#f} for using the default value from Knot,
24669 @item @code{'none} for not using the zone file at all,
24670 @item @code{'difference} for computing the difference between already available
24671 contents and zone contents and applying it to the current zone contents,
24672 @item @code{'difference-no-serial} for the same as @code{'difference}, but
24673 ignoring the SOA serial in the zone file, while the server takes care of it
24675 @item @code{'whole} for loading zone contents from the zone file.
24678 @item @code{journal-content} (default: @code{#f})
24679 The way the journal is used to store zone and its changes. Possible values
24680 are @code{'none} to not use it at all, @code{'changes} to store changes and
24681 @code{'all} to store contents. @code{#f} does not set this option, so the
24682 default value from Knot is used.
24684 @item @code{max-journal-usage} (default: @code{#f})
24685 The maximum size for the journal on disk. @code{#f} does not set this option,
24686 so the default value from Knot is used.
24688 @item @code{max-journal-depth} (default: @code{#f})
24689 The maximum size of the history. @code{#f} does not set this option, so the
24690 default value from Knot is used.
24692 @item @code{max-zone-size} (default: @code{#f})
24693 The maximum size of the zone file. This limit is enforced for incoming
24694 transfer and updates. @code{#f} does not set this option, so the default
24695 value from Knot is used.
24697 @item @code{dnssec-policy} (default: @code{#f})
24698 A reference to a @code{knot-policy-configuration} record, or the special
24699 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
24702 @item @code{serial-policy} (default: @code{'increment})
24703 A policy between @code{'increment} and @code{'unixtime}.
24708 @deftp {Data Type} knot-configuration
24709 Data type representing the Knot configuration.
24710 This type has the following parameters:
24713 @item @code{knot} (default: @code{knot})
24716 @item @code{run-directory} (default: @code{"/var/run/knot"})
24717 The run directory. This directory will be used for pid file and sockets.
24719 @item @code{includes} (default: @code{'()})
24720 A list of strings or file-like objects denoting other files that must be
24721 included at the top of the configuration file.
24723 @cindex secrets, Knot service
24724 This can be used to manage secrets out-of-band. For example, secret
24725 keys may be stored in an out-of-band file not managed by Guix, and
24726 thus not visible in @file{/gnu/store}---e.g., you could store secret
24727 key configuration in @file{/etc/knot/secrets.conf} and add this file
24728 to the @code{includes} list.
24730 One can generate a secret tsig key (for nsupdate and zone transfers with the
24731 keymgr command from the knot package. Note that the package is not automatically
24732 installed by the service. The following example shows how to generate a new
24736 keymgr -t mysecret > /etc/knot/secrets.conf
24737 chmod 600 /etc/knot/secrets.conf
24740 Also note that the generated key will be named @var{mysecret}, so it is the
24741 name that needs to be used in the @var{key} field of the
24742 @code{knot-acl-configuration} record and in other places that need to refer
24745 It can also be used to add configuration not supported by this interface.
24747 @item @code{listen-v4} (default: @code{"0.0.0.0"})
24748 An ip address on which to listen.
24750 @item @code{listen-v6} (default: @code{"::"})
24751 An ip address on which to listen.
24753 @item @code{listen-port} (default: @code{53})
24754 A port on which to listen.
24756 @item @code{keys} (default: @code{'()})
24757 The list of knot-key-configuration used by this configuration.
24759 @item @code{acls} (default: @code{'()})
24760 The list of knot-acl-configuration used by this configuration.
24762 @item @code{remotes} (default: @code{'()})
24763 The list of knot-remote-configuration used by this configuration.
24765 @item @code{zones} (default: @code{'()})
24766 The list of knot-zone-configuration used by this configuration.
24771 @subsubheading Knot Resolver Service
24773 @deffn {Scheme Variable} knot-resolver-service-type
24774 This is the type of the knot resolver service, whose value should be
24775 an @code{knot-resolver-configuration} object as in this example:
24778 (service knot-resolver-service-type
24779 (knot-resolver-configuration
24780 (kresd-config-file (plain-file "kresd.conf" "
24781 net.listen('192.168.0.1', 5353)
24782 user('knot-resolver', 'knot-resolver')
24783 modules = @{ 'hints > iterate', 'stats', 'predict' @}
24784 cache.size = 100 * MB
24788 For more information, refer its @url{https://knot-resolver.readthedocs.org/en/stable/daemon.html#configuration, manual}.
24791 @deftp {Data Type} knot-resolver-configuration
24792 Data type representing the configuration of knot-resolver.
24795 @item @code{package} (default: @var{knot-resolver})
24796 Package object of the knot DNS resolver.
24798 @item @code{kresd-config-file} (default: %kresd.conf)
24799 File-like object of the kresd configuration file to use, by default it
24800 will listen on @code{127.0.0.1} and @code{::1}.
24802 @item @code{garbage-collection-interval} (default: 1000)
24803 Number of milliseconds for @code{kres-cache-gc} to periodically trim the cache.
24809 @subsubheading Dnsmasq Service
24811 @deffn {Scheme Variable} dnsmasq-service-type
24812 This is the type of the dnsmasq service, whose value should be an
24813 @code{dnsmasq-configuration} object as in this example:
24816 (service dnsmasq-service-type
24817 (dnsmasq-configuration
24819 (servers '("192.168.1.1"))))
24823 @deftp {Data Type} dnsmasq-configuration
24824 Data type representing the configuration of dnsmasq.
24827 @item @code{package} (default: @var{dnsmasq})
24828 Package object of the dnsmasq server.
24830 @item @code{no-hosts?} (default: @code{#f})
24831 When true, don't read the hostnames in /etc/hosts.
24833 @item @code{port} (default: @code{53})
24834 The port to listen on. Setting this to zero completely disables DNS
24835 responses, leaving only DHCP and/or TFTP functions.
24837 @item @code{local-service?} (default: @code{#t})
24838 Accept DNS queries only from hosts whose address is on a local subnet,
24839 ie a subnet for which an interface exists on the server.
24841 @item @code{listen-addresses} (default: @code{'()})
24842 Listen on the given IP addresses.
24844 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
24845 The file to read the IP address of the upstream nameservers from.
24847 @item @code{no-resolv?} (default: @code{#f})
24848 When true, don't read @var{resolv-file}.
24850 @item @code{servers} (default: @code{'()})
24851 Specify IP address of upstream servers directly.
24853 @item @code{addresses} (default: @code{'()})
24854 For each entry, specify an IP address to return for any host in the
24855 given domains. Queries in the domains are never forwarded and always
24856 replied to with the specified IP address.
24858 This is useful for redirecting hosts locally, for example:
24861 (service dnsmasq-service-type
24862 (dnsmasq-configuration
24864 '(; Redirect to a local web-server.
24865 "/example.org/127.0.0.1"
24866 ; Redirect subdomain to a specific IP.
24867 "/subdomain.example.org/192.168.1.42"))))
24870 Note that rules in @file{/etc/hosts} take precedence over this.
24872 @item @code{cache-size} (default: @code{150})
24873 Set the size of dnsmasq's cache. Setting the cache size to zero
24876 @item @code{negative-cache?} (default: @code{#t})
24877 When false, disable negative caching.
24879 @item @code{tftp-enable?} (default: @code{#f})
24880 Whether to enable the built-in TFTP server.
24882 @item @code{tftp-no-fail?} (default: @code{#f})
24883 If true, does not fail dnsmasq if the TFTP server could not start up.
24885 @item @code{tftp-single-port?} (default: @code{#f})
24886 Whether to use only one single port for TFTP.
24888 @item @code{tftp-secure?} (default: @code{#f})
24889 If true, only files owned by the user running the dnsmasq process are accessible.
24891 If dnsmasq is being run as root, different rules apply:
24892 @code{tftp-secure?} has no effect, but only files which have the
24893 world-readable bit set are accessible.
24895 @item @code{tftp-max} (default: @code{#f})
24896 If set, sets the maximal number of concurrent connections allowed.
24898 @item @code{tftp-mtu} (default: @code{#f})
24899 If set, sets the MTU for TFTP packets to that value.
24901 @item @code{tftp-no-blocksize?} (default: @code{#f})
24902 If true, stops the TFTP server from negotiating the blocksize with a client.
24904 @item @code{tftp-lowercase?} (default: @code{#f})
24905 Whether to convert all filenames in TFTP requests to lowercase.
24907 @item @code{tftp-port-range} (default: @code{#f})
24908 If set, fixes the dynamical ports (one per client) to the given range
24909 (@code{"<start>,<end>"}).
24911 @item @code{tftp-root} (default: @code{/var/empty,lo})
24912 Look for files to transfer using TFTP relative to the given directory.
24913 When this is set, TFTP paths which include ".." are rejected, to stop clients
24914 getting outside the specified root. Absolute paths (starting with /) are
24915 allowed, but they must be within the tftp-root. If the optional interface
24916 argument is given, the directory is only used for TFTP requests via that
24919 @item @code{tftp-unique-root} (default: @code{#f})
24920 If set, add the IP or hardware address of the TFTP client as a path component
24921 on the end of the TFTP-root. Only valid if a TFTP root is set and the
24922 directory exists. Defaults to adding IP address (in standard dotted-quad
24925 For instance, if --tftp-root is "/tftp" and client 1.2.3.4 requests file
24926 "myfile" then the effective path will be "/tftp/1.2.3.4/myfile" if
24927 /tftp/1.2.3.4 exists or /tftp/myfile otherwise. When "=mac" is specified
24928 it will append the MAC address instead, using lowercase zero padded digits
24929 separated by dashes, e.g.: 01-02-03-04-aa-bb Note that resolving MAC
24930 addresses is only possible if the client is in the local network or obtained
24931 a DHCP lease from dnsmasq.
24936 @subsubheading ddclient Service
24939 The ddclient service described below runs the ddclient daemon, which takes
24940 care of automatically updating DNS entries for service providers such as
24941 @uref{https://dyn.com/dns/, Dyn}.
24943 The following example show instantiates the service with its default
24947 (service ddclient-service-type)
24950 Note that ddclient needs to access credentials that are stored in a
24951 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
24952 @code{secret-file} below). You are expected to create this file manually, in
24953 an ``out-of-band'' fashion (you @emph{could} make this file part of the
24954 service configuration, for instance by using @code{plain-file}, but it will be
24955 world-readable @i{via} @file{/gnu/store}). See the examples in the
24956 @file{share/ddclient} directory of the @code{ddclient} package.
24958 @c %start of fragment
24960 Available @code{ddclient-configuration} fields are:
24962 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
24963 The ddclient package.
24967 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
24968 The period after which ddclient will retry to check IP and domain name.
24970 Defaults to @samp{300}.
24974 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
24975 Use syslog for the output.
24977 Defaults to @samp{#t}.
24981 @deftypevr {@code{ddclient-configuration} parameter} string mail
24984 Defaults to @samp{"root"}.
24988 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
24989 Mail failed update to user.
24991 Defaults to @samp{"root"}.
24995 @deftypevr {@code{ddclient-configuration} parameter} string pid
24996 The ddclient PID file.
24998 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
25002 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
25003 Enable SSL support.
25005 Defaults to @samp{#t}.
25009 @deftypevr {@code{ddclient-configuration} parameter} string user
25010 Specifies the user name or ID that is used when running ddclient
25013 Defaults to @samp{"ddclient"}.
25017 @deftypevr {@code{ddclient-configuration} parameter} string group
25018 Group of the user who will run the ddclient program.
25020 Defaults to @samp{"ddclient"}.
25024 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
25025 Secret file which will be appended to @file{ddclient.conf} file. This
25026 file contains credentials for use by ddclient. You are expected to
25027 create it manually.
25029 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
25033 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
25034 Extra options will be appended to @file{ddclient.conf} file.
25036 Defaults to @samp{()}.
25041 @c %end of fragment
25045 @subsection VPN Services
25046 @cindex VPN (virtual private network)
25047 @cindex virtual private network (VPN)
25049 The @code{(gnu services vpn)} module provides services related to
25050 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
25051 your machine to connect to a VPN, and a @emph{server} service for your machine
25052 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
25054 @deffn {Scheme Procedure} openvpn-client-service @
25055 [#:config (openvpn-client-configuration)]
25057 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
25060 @deffn {Scheme Procedure} openvpn-server-service @
25061 [#:config (openvpn-server-configuration)]
25063 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
25065 Both can be run simultaneously.
25068 @c %automatically generated documentation
25070 Available @code{openvpn-client-configuration} fields are:
25072 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
25073 The OpenVPN package.
25077 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
25078 The OpenVPN pid file.
25080 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
25084 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
25085 The protocol (UDP or TCP) used to open a channel between clients and
25088 Defaults to @samp{udp}.
25092 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
25093 The device type used to represent the VPN connection.
25095 Defaults to @samp{tun}.
25099 If you do not have some of these files (eg.@: you use a username and
25100 password), you can disable any of the following three fields by setting
25101 it to @code{'disabled}.
25103 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string ca
25104 The certificate authority to check connections against.
25106 Defaults to @samp{"/etc/openvpn/ca.crt"}.
25110 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string cert
25111 The certificate of the machine the daemon is running on. It should be
25112 signed by the authority given in @code{ca}.
25114 Defaults to @samp{"/etc/openvpn/client.crt"}.
25118 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string key
25119 The key of the machine the daemon is running on. It must be the key whose
25120 certificate is @code{cert}.
25122 Defaults to @samp{"/etc/openvpn/client.key"}.
25126 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
25127 Whether to use the lzo compression algorithm.
25129 Defaults to @samp{#t}.
25133 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
25134 Don't re-read key files across SIGUSR1 or --ping-restart.
25136 Defaults to @samp{#t}.
25140 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
25141 Don't close and reopen TUN/TAP device or run up/down scripts across
25142 SIGUSR1 or --ping-restart restarts.
25144 Defaults to @samp{#t}.
25148 @deftypevr {@code{openvpn-client-configuration} parameter} boolean fast-io?
25149 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
25150 poll/epoll/select prior to the write operation.
25152 Defaults to @samp{#f}.
25155 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
25158 Defaults to @samp{3}.
25162 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
25163 Add an additional layer of HMAC authentication on top of the TLS control
25164 channel to protect against DoS attacks.
25166 Defaults to @samp{#f}.
25170 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string auth-user-pass
25171 Authenticate with server using username/password. The option is a file
25172 containing username/password on 2 lines. Do not use a file-like object as it
25173 would be added to the store and readable by any user.
25175 Defaults to @samp{'disabled}.
25178 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
25179 Whether to check the server certificate has server usage extension.
25181 Defaults to @samp{#t}.
25185 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
25186 Bind to a specific local port number.
25188 Defaults to @samp{#f}.
25192 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
25193 Retry resolving server address.
25195 Defaults to @samp{#t}.
25199 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
25200 A list of remote servers to connect to.
25202 Defaults to @samp{()}.
25204 Available @code{openvpn-remote-configuration} fields are:
25206 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
25209 Defaults to @samp{"my-server"}.
25213 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
25214 Port number the server listens to.
25216 Defaults to @samp{1194}.
25221 @c %end of automatic openvpn-client documentation
25223 @c %automatically generated documentation
25225 Available @code{openvpn-server-configuration} fields are:
25227 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
25228 The OpenVPN package.
25232 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
25233 The OpenVPN pid file.
25235 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
25239 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
25240 The protocol (UDP or TCP) used to open a channel between clients and
25243 Defaults to @samp{udp}.
25247 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
25248 The device type used to represent the VPN connection.
25250 Defaults to @samp{tun}.
25254 If you do not have some of these files (eg.@: you use a username and
25255 password), you can disable any of the following three fields by setting
25256 it to @code{'disabled}.
25258 @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string ca
25259 The certificate authority to check connections against.
25261 Defaults to @samp{"/etc/openvpn/ca.crt"}.
25265 @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string cert
25266 The certificate of the machine the daemon is running on. It should be
25267 signed by the authority given in @code{ca}.
25269 Defaults to @samp{"/etc/openvpn/client.crt"}.
25273 @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string key
25274 The key of the machine the daemon is running on. It must be the key whose
25275 certificate is @code{cert}.
25277 Defaults to @samp{"/etc/openvpn/client.key"}.
25281 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
25282 Whether to use the lzo compression algorithm.
25284 Defaults to @samp{#t}.
25288 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
25289 Don't re-read key files across SIGUSR1 or --ping-restart.
25291 Defaults to @samp{#t}.
25295 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
25296 Don't close and reopen TUN/TAP device or run up/down scripts across
25297 SIGUSR1 or --ping-restart restarts.
25299 Defaults to @samp{#t}.
25303 @deftypevr {@code{openvpn-server-configuration} parameter} boolean fast-io?
25304 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
25305 poll/epoll/select prior to the write operation.
25307 Defaults to @samp{#f}.
25310 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
25313 Defaults to @samp{3}.
25317 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
25318 Add an additional layer of HMAC authentication on top of the TLS control
25319 channel to protect against DoS attacks.
25321 Defaults to @samp{#f}.
25325 @deftypevr {@code{openvpn-server-configuration} parameter} number port
25326 Specifies the port number on which the server listens.
25328 Defaults to @samp{1194}.
25332 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
25333 An ip and mask specifying the subnet inside the virtual network.
25335 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
25339 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
25340 A CIDR notation specifying the IPv6 subnet inside the virtual network.
25342 Defaults to @samp{#f}.
25346 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
25347 The Diffie-Hellman parameters file.
25349 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
25353 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
25354 The file that records client IPs.
25356 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
25360 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
25361 When true, the server will act as a gateway for its clients.
25363 Defaults to @samp{#f}.
25367 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
25368 When true, clients are allowed to talk to each other inside the VPN.
25370 Defaults to @samp{#f}.
25374 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
25375 Causes ping-like messages to be sent back and forth over the link so
25376 that each side knows when the other side has gone down. @code{keepalive}
25377 requires a pair. The first element is the period of the ping sending,
25378 and the second element is the timeout before considering the other side
25383 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
25384 The maximum number of clients.
25386 Defaults to @samp{100}.
25390 @deftypevr {@code{openvpn-server-configuration} parameter} string status
25391 The status file. This file shows a small report on current connection.
25392 It is truncated and rewritten every minute.
25394 Defaults to @samp{"/var/run/openvpn/status"}.
25398 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
25399 The list of configuration for some clients.
25401 Defaults to @samp{()}.
25403 Available @code{openvpn-ccd-configuration} fields are:
25405 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
25408 Defaults to @samp{"client"}.
25412 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
25415 Defaults to @samp{#f}.
25419 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
25422 Defaults to @samp{#f}.
25429 @c %end of automatic openvpn-server documentation
25432 @node Network File System
25433 @subsection Network File System
25436 The @code{(gnu services nfs)} module provides the following services,
25437 which are most commonly used in relation to mounting or exporting
25438 directory trees as @dfn{network file systems} (NFS).
25440 While it is possible to use the individual components that together make
25441 up a Network File System service, we recommended to configure an NFS
25442 server with the @code{nfs-service-type}.
25444 @subsubheading NFS Service
25445 @cindex NFS, server
25447 The NFS service takes care of setting up all NFS component services,
25448 kernel configuration file systems, and installs configuration files in
25449 the locations that NFS expects.
25451 @defvr {Scheme Variable} nfs-service-type
25452 A service type for a complete NFS server.
25455 @deftp {Data Type} nfs-configuration
25456 This data type represents the configuration of the NFS service and all
25459 It has the following parameters:
25461 @item @code{nfs-utils} (default: @code{nfs-utils})
25462 The nfs-utils package to use.
25464 @item @code{nfs-versions} (default: @code{'("4.2" "4.1" "4.0")})
25465 If a list of string values is provided, the @command{rpc.nfsd} daemon
25466 will be limited to supporting the given versions of the NFS protocol.
25468 @item @code{exports} (default: @code{'()})
25469 This is a list of directories the NFS server should export. Each entry
25470 is a list consisting of two elements: a directory name and a string
25471 containing all options. This is an example in which the directory
25472 @file{/export} is served to all NFS clients as a read-only share:
25478 "*(ro,insecure,no_subtree_check,crossmnt,fsid=0)"))))
25481 @item @code{rpcmountd-port} (default: @code{#f})
25482 The network port that the @command{rpc.mountd} daemon should use.
25484 @item @code{rpcstatd-port} (default: @code{#f})
25485 The network port that the @command{rpc.statd} daemon should use.
25487 @item @code{rpcbind} (default: @code{rpcbind})
25488 The rpcbind package to use.
25490 @item @code{idmap-domain} (default: @code{"localdomain"})
25491 The local NFSv4 domain name.
25493 @item @code{nfsd-port} (default: @code{2049})
25494 The network port that the @command{nfsd} daemon should use.
25496 @item @code{nfsd-threads} (default: @code{8})
25497 The number of threads used by the @command{nfsd} daemon.
25499 @item @code{nfsd-tcp?} (default: @code{#t})
25500 Whether the @command{nfsd} daemon should listen on a TCP socket.
25502 @item @code{nfsd-udp?} (default: @code{#f})
25503 Whether the @command{nfsd} daemon should listen on a UDP socket.
25505 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
25506 The directory where the pipefs file system is mounted.
25508 @item @code{debug} (default: @code{'()"})
25509 A list of subsystems for which debugging output should be enabled. This
25510 is a list of symbols. Any of these symbols are valid: @code{nfsd},
25511 @code{nfs}, @code{rpc}, @code{idmap}, @code{statd}, or @code{mountd}.
25515 If you don't need a complete NFS service or prefer to build it yourself
25516 you can use the individual component services that are documented below.
25518 @subsubheading RPC Bind Service
25521 The RPC Bind service provides a facility to map program numbers into
25522 universal addresses.
25523 Many NFS related services use this facility. Hence it is automatically
25524 started when a dependent service starts.
25526 @defvr {Scheme Variable} rpcbind-service-type
25527 A service type for the RPC portmapper daemon.
25531 @deftp {Data Type} rpcbind-configuration
25532 Data type representing the configuration of the RPC Bind Service.
25533 This type has the following parameters:
25535 @item @code{rpcbind} (default: @code{rpcbind})
25536 The rpcbind package to use.
25538 @item @code{warm-start?} (default: @code{#t})
25539 If this parameter is @code{#t}, then the daemon will read a
25540 state file on startup thus reloading state information saved by a previous
25546 @subsubheading Pipefs Pseudo File System
25550 The pipefs file system is used to transfer NFS related data
25551 between the kernel and user space programs.
25553 @defvr {Scheme Variable} pipefs-service-type
25554 A service type for the pipefs pseudo file system.
25557 @deftp {Data Type} pipefs-configuration
25558 Data type representing the configuration of the pipefs pseudo file system service.
25559 This type has the following parameters:
25561 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
25562 The directory to which the file system is to be attached.
25567 @subsubheading GSS Daemon Service
25570 @cindex global security system
25572 The @dfn{global security system} (GSS) daemon provides strong security for RPC
25574 Before exchanging RPC requests an RPC client must establish a security
25575 context. Typically this is done using the Kerberos command @command{kinit}
25576 or automatically at login time using PAM services (@pxref{Kerberos Services}).
25578 @defvr {Scheme Variable} gss-service-type
25579 A service type for the Global Security System (GSS) daemon.
25582 @deftp {Data Type} gss-configuration
25583 Data type representing the configuration of the GSS daemon service.
25584 This type has the following parameters:
25586 @item @code{nfs-utils} (default: @code{nfs-utils})
25587 The package in which the @command{rpc.gssd} command is to be found.
25589 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
25590 The directory where the pipefs file system is mounted.
25596 @subsubheading IDMAP Daemon Service
25598 @cindex name mapper
25600 The idmap daemon service provides mapping between user IDs and user names.
25601 Typically it is required in order to access file systems mounted via NFSv4.
25603 @defvr {Scheme Variable} idmap-service-type
25604 A service type for the Identity Mapper (IDMAP) daemon.
25607 @deftp {Data Type} idmap-configuration
25608 Data type representing the configuration of the IDMAP daemon service.
25609 This type has the following parameters:
25611 @item @code{nfs-utils} (default: @code{nfs-utils})
25612 The package in which the @command{rpc.idmapd} command is to be found.
25614 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
25615 The directory where the pipefs file system is mounted.
25617 @item @code{domain} (default: @code{#f})
25618 The local NFSv4 domain name.
25619 This must be a string or @code{#f}.
25620 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
25622 @item @code{verbosity} (default: @code{0})
25623 The verbosity level of the daemon.
25628 @node Continuous Integration
25629 @subsection Continuous Integration
25631 @cindex continuous integration
25632 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
25633 continuous integration tool for Guix. It can be used both for development and
25634 for providing substitutes to others (@pxref{Substitutes}).
25636 The @code{(gnu services cuirass)} module provides the following service.
25638 @defvr {Scheme Procedure} cuirass-service-type
25639 The type of the Cuirass service. Its value must be a
25640 @code{cuirass-configuration} object, as described below.
25643 To add build jobs, you have to set the @code{specifications} field of the
25644 configuration. Here is an example of a service that polls the Guix repository
25645 and builds the packages from a manifest. Some of the packages are defined in
25646 the @code{"custom-packages"} input, which is the equivalent of
25647 @env{GUIX_PACKAGE_PATH}.
25650 (define %cuirass-specs
25652 '((#:name . "my-manifest")
25653 (#:load-path-inputs . ("guix"))
25654 (#:package-path-inputs . ("custom-packages"))
25655 (#:proc-input . "guix")
25656 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
25657 (#:proc . cuirass-jobs)
25658 (#:proc-args . ((subset . "manifests")
25659 (systems . ("x86_64-linux"))
25660 (manifests . (("config" . "guix/manifest.scm")))))
25661 (#:inputs . (((#:name . "guix")
25662 (#:url . "git://git.savannah.gnu.org/guix.git")
25663 (#:load-path . ".")
25664 (#:branch . "master")
25665 (#:no-compile? . #t))
25666 ((#:name . "config")
25667 (#:url . "https://git.example.org/config.git")
25668 (#:load-path . ".")
25669 (#:branch . "master")
25670 (#:no-compile? . #t))
25671 ((#:name . "custom-packages")
25672 (#:url . "https://git.example.org/custom-packages.git")
25673 (#:load-path . ".")
25674 (#:branch . "master")
25675 (#:no-compile? . #t)))))))
25677 (service cuirass-service-type
25678 (cuirass-configuration
25679 (specifications %cuirass-specs)))
25682 While information related to build jobs is located directly in the
25683 specifications, global settings for the @command{cuirass} process are
25684 accessible in other @code{cuirass-configuration} fields.
25686 @deftp {Data Type} cuirass-configuration
25687 Data type representing the configuration of Cuirass.
25690 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
25691 Location of the log file.
25693 @item @code{web-log-file} (default: @code{"/var/log/cuirass-web.log"})
25694 Location of the log file used by the web interface.
25696 @item @code{queries-log-file} (default: @code{#f})
25697 Location of the SQL queries log file. By default, SQL queries logging is
25700 @item @code{web-queries-log-file} (default: @code{#f})
25701 Location of the web SQL queries log file. By default, web SQL queries
25702 logging is disabled.
25704 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
25705 Location of the repository cache.
25707 @item @code{user} (default: @code{"cuirass"})
25708 Owner of the @code{cuirass} process.
25710 @item @code{group} (default: @code{"cuirass"})
25711 Owner's group of the @code{cuirass} process.
25713 @item @code{interval} (default: @code{60})
25714 Number of seconds between the poll of the repositories followed by the
25717 @item @code{queue-size} (default: @code{1})
25718 Size of the database writer queue.
25720 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
25721 Location of sqlite database which contains the build results and previously
25722 added specifications.
25724 @item @code{ttl} (default: @code{(* 30 24 3600)})
25725 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
25726 are registered for build results. This means that build results are protected
25727 from garbage collection for at least @var{ttl} seconds.
25729 @item @code{port} (default: @code{8081})
25730 Port number used by the HTTP server.
25732 @item @code{host} (default: @code{"localhost"})
25733 Listen on the network interface for @var{host}. The default is to
25734 accept connections from localhost.
25736 @item @code{specifications} (default: @code{#~'()})
25737 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
25738 where a specification is an association list
25739 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
25740 keys are keywords (@code{#:keyword-example}) as shown in the example
25743 @item @code{use-substitutes?} (default: @code{#f})
25744 This allows using substitutes to avoid building every dependencies of a job
25747 @item @code{one-shot?} (default: @code{#f})
25748 Only evaluate specifications and build derivations once.
25750 @item @code{fallback?} (default: @code{#f})
25751 When substituting a pre-built binary fails, fall back to building
25754 @item @code{extra-options} (default: @code{'()})
25755 Extra options to pass when running the Cuirass processes.
25757 @item @code{cuirass} (default: @code{cuirass})
25758 The Cuirass package to use.
25762 @node Power Management Services
25763 @subsection Power Management Services
25766 @cindex power management with TLP
25767 @subsubheading TLP daemon
25769 The @code{(gnu services pm)} module provides a Guix service definition
25770 for the Linux power management tool TLP.
25772 TLP enables various powersaving modes in userspace and kernel.
25773 Contrary to @code{upower-service}, it is not a passive,
25774 monitoring tool, as it will apply custom settings each time a new power
25775 source is detected. More information can be found at
25776 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
25778 @deffn {Scheme Variable} tlp-service-type
25779 The service type for the TLP tool. The default settings are optimised
25780 for battery life on most systems, but you can tweak them to your heart's
25781 content by adding a valid @code{tlp-configuration}:
25783 (service tlp-service-type
25785 (cpu-scaling-governor-on-ac (list "performance"))
25786 (sched-powersave-on-bat? #t)))
25790 Each parameter definition is preceded by its type; for example,
25791 @samp{boolean foo} indicates that the @code{foo} parameter
25792 should be specified as a boolean. Types starting with
25793 @code{maybe-} denote parameters that won't show up in TLP config file
25794 when their value is @code{'disabled}.
25796 @c The following documentation was initially generated by
25797 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
25798 @c documentation is better, so we shouldn't hesitate to edit below as
25799 @c needed. However if the change you want to make to this documentation
25800 @c can be done in an automated way, it's probably easier to change
25801 @c (generate-documentation) than to make it below and have to deal with
25802 @c the churn as TLP updates.
25804 Available @code{tlp-configuration} fields are:
25806 @deftypevr {@code{tlp-configuration} parameter} package tlp
25811 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
25812 Set to true if you wish to enable TLP.
25814 Defaults to @samp{#t}.
25818 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
25819 Default mode when no power supply can be detected. Alternatives are AC
25822 Defaults to @samp{"AC"}.
25826 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
25827 Number of seconds Linux kernel has to wait after the disk goes idle,
25828 before syncing on AC.
25830 Defaults to @samp{0}.
25834 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
25835 Same as @code{disk-idle-ac} but on BAT mode.
25837 Defaults to @samp{2}.
25841 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
25842 Dirty pages flushing periodicity, expressed in seconds.
25844 Defaults to @samp{15}.
25848 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
25849 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
25851 Defaults to @samp{60}.
25855 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
25856 CPU frequency scaling governor on AC mode. With intel_pstate driver,
25857 alternatives are powersave and performance. With acpi-cpufreq driver,
25858 alternatives are ondemand, powersave, performance and conservative.
25860 Defaults to @samp{disabled}.
25864 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
25865 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
25867 Defaults to @samp{disabled}.
25871 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
25872 Set the min available frequency for the scaling governor on AC.
25874 Defaults to @samp{disabled}.
25878 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
25879 Set the max available frequency for the scaling governor on AC.
25881 Defaults to @samp{disabled}.
25885 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
25886 Set the min available frequency for the scaling governor on BAT.
25888 Defaults to @samp{disabled}.
25892 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
25893 Set the max available frequency for the scaling governor on BAT.
25895 Defaults to @samp{disabled}.
25899 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
25900 Limit the min P-state to control the power dissipation of the CPU, in AC
25901 mode. Values are stated as a percentage of the available performance.
25903 Defaults to @samp{disabled}.
25907 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
25908 Limit the max P-state to control the power dissipation of the CPU, in AC
25909 mode. Values are stated as a percentage of the available performance.
25911 Defaults to @samp{disabled}.
25915 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
25916 Same as @code{cpu-min-perf-on-ac} on BAT mode.
25918 Defaults to @samp{disabled}.
25922 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
25923 Same as @code{cpu-max-perf-on-ac} on BAT mode.
25925 Defaults to @samp{disabled}.
25929 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
25930 Enable CPU turbo boost feature on AC mode.
25932 Defaults to @samp{disabled}.
25936 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
25937 Same as @code{cpu-boost-on-ac?} on BAT mode.
25939 Defaults to @samp{disabled}.
25943 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
25944 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
25945 used under light load conditions.
25947 Defaults to @samp{#f}.
25951 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
25952 Same as @code{sched-powersave-on-ac?} but on BAT mode.
25954 Defaults to @samp{#t}.
25958 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
25959 Enable Linux kernel NMI watchdog.
25961 Defaults to @samp{#f}.
25965 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
25966 For Linux kernels with PHC patch applied, change CPU voltages. An
25967 example value would be @samp{"F:V F:V F:V F:V"}.
25969 Defaults to @samp{disabled}.
25973 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
25974 Set CPU performance versus energy saving policy on AC. Alternatives are
25975 performance, normal, powersave.
25977 Defaults to @samp{"performance"}.
25981 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
25982 Same as @code{energy-perf-policy-ac} but on BAT mode.
25984 Defaults to @samp{"powersave"}.
25988 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
25993 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
25994 Hard disk advanced power management level.
25998 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
25999 Same as @code{disk-apm-bat} but on BAT mode.
26003 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
26004 Hard disk spin down timeout. One value has to be specified for each
26005 declared hard disk.
26007 Defaults to @samp{disabled}.
26011 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
26012 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
26014 Defaults to @samp{disabled}.
26018 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
26019 Select IO scheduler for disk devices. One value has to be specified for
26020 each declared hard disk. Example alternatives are cfq, deadline and
26023 Defaults to @samp{disabled}.
26027 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
26028 SATA aggressive link power management (ALPM) level. Alternatives are
26029 min_power, medium_power, max_performance.
26031 Defaults to @samp{"max_performance"}.
26035 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
26036 Same as @code{sata-linkpwr-ac} but on BAT mode.
26038 Defaults to @samp{"min_power"}.
26042 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
26043 Exclude specified SATA host devices for link power management.
26045 Defaults to @samp{disabled}.
26049 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
26050 Enable Runtime Power Management for AHCI controller and disks on AC
26053 Defaults to @samp{disabled}.
26057 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
26058 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
26060 Defaults to @samp{disabled}.
26064 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
26065 Seconds of inactivity before disk is suspended.
26067 Defaults to @samp{15}.
26071 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
26072 PCI Express Active State Power Management level. Alternatives are
26073 default, performance, powersave.
26075 Defaults to @samp{"performance"}.
26079 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
26080 Same as @code{pcie-aspm-ac} but on BAT mode.
26082 Defaults to @samp{"powersave"}.
26086 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
26087 Radeon graphics clock speed level. Alternatives are low, mid, high,
26090 Defaults to @samp{"high"}.
26094 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
26095 Same as @code{radeon-power-ac} but on BAT mode.
26097 Defaults to @samp{"low"}.
26101 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
26102 Radeon dynamic power management method (DPM). Alternatives are battery,
26105 Defaults to @samp{"performance"}.
26109 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
26110 Same as @code{radeon-dpm-state-ac} but on BAT mode.
26112 Defaults to @samp{"battery"}.
26116 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
26117 Radeon DPM performance level. Alternatives are auto, low, high.
26119 Defaults to @samp{"auto"}.
26123 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
26124 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
26126 Defaults to @samp{"auto"}.
26130 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
26131 Wifi power saving mode.
26133 Defaults to @samp{#f}.
26137 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
26138 Same as @code{wifi-power-ac?} but on BAT mode.
26140 Defaults to @samp{#t}.
26144 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
26145 Disable wake on LAN.
26147 Defaults to @samp{#t}.
26151 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
26152 Timeout duration in seconds before activating audio power saving on
26153 Intel HDA and AC97 devices. A value of 0 disables power saving.
26155 Defaults to @samp{0}.
26159 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
26160 Same as @code{sound-powersave-ac} but on BAT mode.
26162 Defaults to @samp{1}.
26166 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
26167 Disable controller in powersaving mode on Intel HDA devices.
26169 Defaults to @samp{#t}.
26173 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
26174 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
26175 powered on again by releasing (and reinserting) the eject lever or by
26176 pressing the disc eject button on newer models.
26178 Defaults to @samp{#f}.
26182 @deftypevr {@code{tlp-configuration} parameter} string bay-device
26183 Name of the optical drive device to power off.
26185 Defaults to @samp{"sr0"}.
26189 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
26190 Runtime Power Management for PCI(e) bus devices. Alternatives are on
26193 Defaults to @samp{"on"}.
26197 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
26198 Same as @code{runtime-pm-ac} but on BAT mode.
26200 Defaults to @samp{"auto"}.
26204 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
26205 Runtime Power Management for all PCI(e) bus devices, except blacklisted
26208 Defaults to @samp{#t}.
26212 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
26213 Exclude specified PCI(e) device addresses from Runtime Power Management.
26215 Defaults to @samp{disabled}.
26219 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
26220 Exclude PCI(e) devices assigned to the specified drivers from Runtime
26225 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
26226 Enable USB autosuspend feature.
26228 Defaults to @samp{#t}.
26232 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
26233 Exclude specified devices from USB autosuspend.
26235 Defaults to @samp{disabled}.
26239 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
26240 Exclude WWAN devices from USB autosuspend.
26242 Defaults to @samp{#t}.
26246 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
26247 Include specified devices into USB autosuspend, even if they are already
26248 excluded by the driver or via @code{usb-blacklist-wwan?}.
26250 Defaults to @samp{disabled}.
26254 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
26255 Enable USB autosuspend before shutdown.
26257 Defaults to @samp{disabled}.
26261 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
26262 Restore radio device state (bluetooth, wifi, wwan) from previous
26263 shutdown on system startup.
26265 Defaults to @samp{#f}.
26270 @cindex CPU frequency scaling with thermald
26271 @subsubheading Thermald daemon
26273 The @code{(gnu services pm)} module provides an interface to
26274 thermald, a CPU frequency scaling service which helps prevent overheating.
26276 @defvr {Scheme Variable} thermald-service-type
26277 This is the service type for
26278 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
26279 Thermal Daemon, which is responsible for controlling the thermal state
26280 of processors and preventing overheating.
26283 @deftp {Data Type} thermald-configuration
26284 Data type representing the configuration of @code{thermald-service-type}.
26287 @item @code{ignore-cpuid-check?} (default: @code{#f})
26288 Ignore cpuid check for supported CPU models.
26290 @item @code{thermald} (default: @var{thermald})
26291 Package object of thermald.
26296 @node Audio Services
26297 @subsection Audio Services
26299 The @code{(gnu services audio)} module provides a service to start MPD
26300 (the Music Player Daemon).
26303 @subsubheading Music Player Daemon
26305 The Music Player Daemon (MPD) is a service that can play music while
26306 being controlled from the local machine or over the network by a variety
26309 The following example shows how one might run @code{mpd} as user
26310 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
26313 (service mpd-service-type
26319 @defvr {Scheme Variable} mpd-service-type
26320 The service type for @command{mpd}
26323 @deftp {Data Type} mpd-configuration
26324 Data type representing the configuration of @command{mpd}.
26327 @item @code{user} (default: @code{"mpd"})
26328 The user to run mpd as.
26330 @item @code{music-dir} (default: @code{"~/Music"})
26331 The directory to scan for music files.
26333 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
26334 The directory to store playlists.
26336 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
26337 The location of the music database.
26339 @item @code{state-file} (default: @code{"~/.mpd/state"})
26340 The location of the file that stores current MPD's state.
26342 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
26343 The location of the sticker database.
26345 @item @code{port} (default: @code{"6600"})
26346 The port to run mpd on.
26348 @item @code{address} (default: @code{"any"})
26349 The address that mpd will bind to. To use a Unix domain socket,
26350 an absolute path can be specified here.
26352 @item @code{outputs} (default: @code{"(list (mpd-output))"})
26353 The audio outputs that MPD can use. By default this is a single output using pulseaudio.
26358 @deftp {Data Type} mpd-output
26359 Data type representing an @command{mpd} audio output.
26362 @item @code{name} (default: @code{"MPD"})
26363 The name of the audio output.
26365 @item @code{type} (default: @code{"pulse"})
26366 The type of audio output.
26368 @item @code{enabled?} (default: @code{#t})
26369 Specifies whether this audio output is enabled when MPD is started. By
26370 default, all audio outputs are enabled. This is just the default
26371 setting when there is no state file; with a state file, the previous
26374 @item @code{tags?} (default: @code{#t})
26375 If set to @code{#f}, then MPD will not send tags to this output. This
26376 is only useful for output plugins that can receive tags, for example the
26377 @code{httpd} output plugin.
26379 @item @code{always-on?} (default: @code{#f})
26380 If set to @code{#t}, then MPD attempts to keep this audio output always
26381 open. This may be useful for streaming servers, when you don’t want to
26382 disconnect all listeners even when playback is accidentally stopped.
26384 @item @code{mixer-type}
26385 This field accepts a symbol that specifies which mixer should be used
26386 for this audio output: the @code{hardware} mixer, the @code{software}
26387 mixer, the @code{null} mixer (allows setting the volume, but with no
26388 effect; this can be used as a trick to implement an external mixer
26389 External Mixer) or no mixer (@code{none}).
26391 @item @code{extra-options} (default: @code{'()})
26392 An association list of option symbols to string values to be appended to
26393 the audio output configuration.
26398 The following example shows a configuration of @code{mpd} that provides
26399 an HTTP audio streaming output.
26402 (service mpd-service-type
26410 `((encoder . "vorbis")
26411 (port . "8080"))))))))
26415 @node Virtualization Services
26416 @subsection Virtualization Services
26418 The @code{(gnu services virtualization)} module provides services for
26419 the libvirt and virtlog daemons, as well as other virtualization-related
26422 @subsubheading Libvirt daemon
26424 @code{libvirtd} is the server side daemon component of the libvirt
26425 virtualization management system. This daemon runs on host servers
26426 and performs required management tasks for virtualized guests.
26428 @deffn {Scheme Variable} libvirt-service-type
26429 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
26430 Its value must be a @code{libvirt-configuration}.
26433 (service libvirt-service-type
26434 (libvirt-configuration
26435 (unix-sock-group "libvirt")
26436 (tls-port "16555")))
26440 @c Auto-generated with (generate-libvirt-documentation)
26441 Available @code{libvirt-configuration} fields are:
26443 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
26448 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
26449 Flag listening for secure TLS connections on the public TCP/IP port.
26450 You must set @code{listen} for this to have any effect.
26452 It is necessary to setup a CA and issue server certificates before using
26455 Defaults to @samp{#t}.
26459 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
26460 Listen for unencrypted TCP connections on the public TCP/IP port. You must
26461 set @code{listen} for this to have any effect.
26463 Using the TCP socket requires SASL authentication by default. Only SASL
26464 mechanisms which support data encryption are allowed. This is
26465 DIGEST_MD5 and GSSAPI (Kerberos5).
26467 Defaults to @samp{#f}.
26471 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
26472 Port for accepting secure TLS connections. This can be a port number,
26475 Defaults to @samp{"16514"}.
26479 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
26480 Port for accepting insecure TCP connections. This can be a port number,
26483 Defaults to @samp{"16509"}.
26487 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
26488 IP address or hostname used for client connections.
26490 Defaults to @samp{"0.0.0.0"}.
26494 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
26495 Flag toggling mDNS advertisement of the libvirt service.
26497 Alternatively can disable for all services on a host by stopping the
26500 Defaults to @samp{#f}.
26504 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
26505 Default mDNS advertisement name. This must be unique on the immediate
26508 Defaults to @samp{"Virtualization Host <hostname>"}.
26512 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
26513 UNIX domain socket group ownership. This can be used to allow a
26514 'trusted' set of users access to management capabilities without
26517 Defaults to @samp{"root"}.
26521 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
26522 UNIX socket permissions for the R/O socket. This is used for monitoring
26525 Defaults to @samp{"0777"}.
26529 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
26530 UNIX socket permissions for the R/W socket. Default allows only root.
26531 If PolicyKit is enabled on the socket, the default will change to allow
26532 everyone (eg, 0777)
26534 Defaults to @samp{"0770"}.
26538 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
26539 UNIX socket permissions for the admin socket. Default allows only owner
26540 (root), do not change it unless you are sure to whom you are exposing
26543 Defaults to @samp{"0777"}.
26547 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
26548 The directory in which sockets will be found/created.
26550 Defaults to @samp{"/var/run/libvirt"}.
26554 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
26555 Authentication scheme for UNIX read-only sockets. By default socket
26556 permissions allow anyone to connect
26558 Defaults to @samp{"polkit"}.
26562 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
26563 Authentication scheme for UNIX read-write sockets. By default socket
26564 permissions only allow root. If PolicyKit support was compiled into
26565 libvirt, the default will be to use 'polkit' auth.
26567 Defaults to @samp{"polkit"}.
26571 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
26572 Authentication scheme for TCP sockets. If you don't enable SASL, then
26573 all TCP traffic is cleartext. Don't do this outside of a dev/test
26576 Defaults to @samp{"sasl"}.
26580 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
26581 Authentication scheme for TLS sockets. TLS sockets already have
26582 encryption provided by the TLS layer, and limited authentication is done
26585 It is possible to make use of any SASL authentication mechanism as well,
26586 by using 'sasl' for this option
26588 Defaults to @samp{"none"}.
26592 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
26593 API access control scheme.
26595 By default an authenticated user is allowed access to all APIs. Access
26596 drivers can place restrictions on this.
26598 Defaults to @samp{()}.
26602 @deftypevr {@code{libvirt-configuration} parameter} string key-file
26603 Server key file path. If set to an empty string, then no private key is
26606 Defaults to @samp{""}.
26610 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
26611 Server key file path. If set to an empty string, then no certificate is
26614 Defaults to @samp{""}.
26618 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
26619 Server key file path. If set to an empty string, then no CA certificate
26622 Defaults to @samp{""}.
26626 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
26627 Certificate revocation list path. If set to an empty string, then no
26630 Defaults to @samp{""}.
26634 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
26635 Disable verification of our own server certificates.
26637 When libvirtd starts it performs some sanity checks against its own
26640 Defaults to @samp{#f}.
26644 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
26645 Disable verification of client certificates.
26647 Client certificate verification is the primary authentication mechanism.
26648 Any client which does not present a certificate signed by the CA will be
26651 Defaults to @samp{#f}.
26655 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
26656 Whitelist of allowed x509 Distinguished Name.
26658 Defaults to @samp{()}.
26662 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
26663 Whitelist of allowed SASL usernames. The format for username depends on
26664 the SASL authentication mechanism.
26666 Defaults to @samp{()}.
26670 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
26671 Override the compile time default TLS priority string. The default is
26672 usually @samp{"NORMAL"} unless overridden at build time. Only set this is it
26673 is desired for libvirt to deviate from the global default settings.
26675 Defaults to @samp{"NORMAL"}.
26679 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
26680 Maximum number of concurrent client connections to allow over all
26683 Defaults to @samp{5000}.
26687 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
26688 Maximum length of queue of connections waiting to be accepted by the
26689 daemon. Note, that some protocols supporting retransmission may obey
26690 this so that a later reattempt at connection succeeds.
26692 Defaults to @samp{1000}.
26696 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
26697 Maximum length of queue of accepted but not yet authenticated clients.
26698 Set this to zero to turn this feature off
26700 Defaults to @samp{20}.
26704 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
26705 Number of workers to start up initially.
26707 Defaults to @samp{5}.
26711 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
26712 Maximum number of worker threads.
26714 If the number of active clients exceeds @code{min-workers}, then more
26715 threads are spawned, up to max_workers limit. Typically you'd want
26716 max_workers to equal maximum number of clients allowed.
26718 Defaults to @samp{20}.
26722 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
26723 Number of priority workers. If all workers from above pool are stuck,
26724 some calls marked as high priority (notably domainDestroy) can be
26725 executed in this pool.
26727 Defaults to @samp{5}.
26731 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
26732 Total global limit on concurrent RPC calls.
26734 Defaults to @samp{20}.
26738 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
26739 Limit on concurrent requests from a single client connection. To avoid
26740 one client monopolizing the server this should be a small fraction of
26741 the global max_requests and max_workers parameter.
26743 Defaults to @samp{5}.
26747 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
26748 Same as @code{min-workers} but for the admin interface.
26750 Defaults to @samp{1}.
26754 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
26755 Same as @code{max-workers} but for the admin interface.
26757 Defaults to @samp{5}.
26761 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
26762 Same as @code{max-clients} but for the admin interface.
26764 Defaults to @samp{5}.
26768 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
26769 Same as @code{max-queued-clients} but for the admin interface.
26771 Defaults to @samp{5}.
26775 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
26776 Same as @code{max-client-requests} but for the admin interface.
26778 Defaults to @samp{5}.
26782 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
26783 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
26785 Defaults to @samp{3}.
26789 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
26792 A filter allows to select a different logging level for a given category
26793 of logs. The format for a filter is one of:
26804 where @code{name} is a string which is matched against the category
26805 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
26806 file, e.g., @samp{"remote"}, @samp{"qemu"}, or @samp{"util.json"} (the
26807 name in the filter can be a substring of the full category name, in
26808 order to match multiple similar categories), the optional @samp{"+"}
26809 prefix tells libvirt to log stack trace for each message matching name,
26810 and @code{x} is the minimal level where matching messages should be
26828 Multiple filters can be defined in a single filters statement, they just
26829 need to be separated by spaces.
26831 Defaults to @samp{"3:remote 4:event"}.
26835 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
26838 An output is one of the places to save logging information. The format
26839 for an output can be:
26843 output goes to stderr
26845 @item x:syslog:name
26846 use syslog for the output and use the given name as the ident
26848 @item x:file:file_path
26849 output to a file, with the given filepath
26852 output to journald logging system
26856 In all case the x prefix is the minimal level, acting as a filter
26873 Multiple outputs can be defined, they just need to be separated by
26876 Defaults to @samp{"3:stderr"}.
26880 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
26881 Allows usage of the auditing subsystem to be altered
26885 0: disable all auditing
26888 1: enable auditing, only if enabled on host
26891 2: enable auditing, and exit if disabled on host.
26895 Defaults to @samp{1}.
26899 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
26900 Send audit messages via libvirt logging infrastructure.
26902 Defaults to @samp{#f}.
26906 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
26907 Host UUID. UUID must not have all digits be the same.
26909 Defaults to @samp{""}.
26913 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
26914 Source to read host UUID.
26918 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
26921 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
26925 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
26928 Defaults to @samp{"smbios"}.
26932 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
26933 A keepalive message is sent to a client after @code{keepalive_interval}
26934 seconds of inactivity to check if the client is still responding. If
26935 set to -1, libvirtd will never send keepalive requests; however clients
26936 can still send them and the daemon will send responses.
26938 Defaults to @samp{5}.
26942 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
26943 Maximum number of keepalive messages that are allowed to be sent to the
26944 client without getting any response before the connection is considered
26947 In other words, the connection is automatically closed approximately
26948 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
26949 the last message received from the client. When @code{keepalive-count}
26950 is set to 0, connections will be automatically closed after
26951 @code{keepalive-interval} seconds of inactivity without sending any
26952 keepalive messages.
26954 Defaults to @samp{5}.
26958 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
26959 Same as above but for admin interface.
26961 Defaults to @samp{5}.
26965 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
26966 Same as above but for admin interface.
26968 Defaults to @samp{5}.
26972 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
26973 Timeout for Open vSwitch calls.
26975 The @code{ovs-vsctl} utility is used for the configuration and its
26976 timeout option is set by default to 5 seconds to avoid potential
26977 infinite waits blocking libvirt.
26979 Defaults to @samp{5}.
26983 @c %end of autogenerated docs
26985 @subsubheading Virtlog daemon
26986 The virtlogd service is a server side daemon component of libvirt that is
26987 used to manage logs from virtual machine consoles.
26989 This daemon is not used directly by libvirt client applications, rather it
26990 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
26991 standalone daemon, the main @code{libvirtd} daemon can be restarted without
26992 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
26993 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
26995 @deffn {Scheme Variable} virtlog-service-type
26996 This is the type of the virtlog daemon.
26997 Its value must be a @code{virtlog-configuration}.
27000 (service virtlog-service-type
27001 (virtlog-configuration
27002 (max-clients 1000)))
27006 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
27007 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
27009 Defaults to @samp{3}.
27013 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
27016 A filter allows to select a different logging level for a given category
27017 of logs The format for a filter is one of:
27028 where @code{name} is a string which is matched against the category
27029 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
27030 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
27031 be a substring of the full category name, in order to match multiple
27032 similar categories), the optional "+" prefix tells libvirt to log stack
27033 trace for each message matching name, and @code{x} is the minimal level
27034 where matching messages should be logged:
27051 Multiple filters can be defined in a single filters statement, they just
27052 need to be separated by spaces.
27054 Defaults to @samp{"3:remote 4:event"}.
27058 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
27061 An output is one of the places to save logging information The format
27062 for an output can be:
27066 output goes to stderr
27068 @item x:syslog:name
27069 use syslog for the output and use the given name as the ident
27071 @item x:file:file_path
27072 output to a file, with the given filepath
27075 output to journald logging system
27079 In all case the x prefix is the minimal level, acting as a filter
27096 Multiple outputs can be defined, they just need to be separated by
27099 Defaults to @samp{"3:stderr"}.
27103 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
27104 Maximum number of concurrent client connections to allow over all
27107 Defaults to @samp{1024}.
27111 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
27112 Maximum file size before rolling over.
27114 Defaults to @samp{2MB}
27118 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
27119 Maximum number of backup files to keep.
27121 Defaults to @samp{3}
27125 @anchor{transparent-emulation-qemu}
27126 @subsubheading Transparent Emulation with QEMU
27129 @cindex @code{binfmt_misc}
27130 @code{qemu-binfmt-service-type} provides support for transparent
27131 emulation of program binaries built for different architectures---e.g.,
27132 it allows you to transparently execute an ARMv7 program on an x86_64
27133 machine. It achieves this by combining the @uref{https://www.qemu.org,
27134 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
27135 This feature only allows you to emulate GNU/Linux on a different
27136 architecture, but see below for GNU/Hurd support.
27138 @defvr {Scheme Variable} qemu-binfmt-service-type
27139 This is the type of the QEMU/binfmt service for transparent emulation.
27140 Its value must be a @code{qemu-binfmt-configuration} object, which
27141 specifies the QEMU package to use as well as the architecture we want to
27145 (service qemu-binfmt-service-type
27146 (qemu-binfmt-configuration
27147 (platforms (lookup-qemu-platforms "arm" "aarch64"))))
27150 In this example, we enable transparent emulation for the ARM and aarch64
27151 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
27152 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
27153 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
27156 @deftp {Data Type} qemu-binfmt-configuration
27157 This is the configuration for the @code{qemu-binfmt} service.
27160 @item @code{platforms} (default: @code{'()})
27161 The list of emulated QEMU platforms. Each item must be a @dfn{platform
27162 object} as returned by @code{lookup-qemu-platforms} (see below).
27164 @item @code{guix-support?} (default: @code{#f})
27165 When it is true, QEMU and all its dependencies are added to the build
27166 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
27167 @option{--chroot-directory} option}). This allows the @code{binfmt_misc}
27168 handlers to be used within the build environment, which in turn means
27169 that you can transparently build programs for another architecture.
27171 For example, let's suppose you're on an x86_64 machine and you have this
27175 (service qemu-binfmt-service-type
27176 (qemu-binfmt-configuration
27177 (platforms (lookup-qemu-platforms "arm"))
27178 (guix-support? #t)))
27184 guix build -s armhf-linux inkscape
27188 and it will build Inkscape for ARMv7 @emph{as if it were a native
27189 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
27190 if you'd like to test a package build for an architecture you don't have
27193 @item @code{qemu} (default: @code{qemu})
27194 The QEMU package to use.
27198 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
27199 Return the list of QEMU platform objects corresponding to
27200 @var{platforms}@dots{}. @var{platforms} must be a list of strings
27201 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
27202 @code{"mips64el"}, and so on.
27205 @deffn {Scheme Procedure} qemu-platform? @var{obj}
27206 Return true if @var{obj} is a platform object.
27209 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
27210 Return the name of @var{platform}---a string such as @code{"arm"}.
27214 @subsubheading The Hurd in a Virtual Machine
27216 @cindex @code{hurd}
27220 Service @code{hurd-vm} provides support for running GNU/Hurd in a
27221 virtual machine (VM), a so-called @dfn{childhurd}. This service is meant
27222 to be used on GNU/Linux and the given GNU/Hurd operating system
27223 configuration is cross-compiled. The virtual machine is a Shepherd
27224 service that can be referred to by the names @code{hurd-vm} and
27225 @code{childhurd} and be controlled with commands such as:
27229 herd stop childhurd
27232 When the service is running, you can view its console by connecting to
27233 it with a VNC client, for example with:
27236 guix environment --ad-hoc tigervnc-client -- \
27237 vncviewer localhost:5900
27240 The default configuration (see @code{hurd-vm-configuration} below)
27241 spawns a secure shell (SSH) server in your GNU/Hurd system, which QEMU
27242 (the virtual machine emulator) redirects to port 10222 on the host.
27243 Thus, you can connect over SSH to the childhurd with:
27246 ssh root@@localhost -p 10022
27249 The childhurd is volatile and stateless: it starts with a fresh root
27250 file system every time you restart it. By default though, all the files
27251 under @file{/etc/childhurd} on the host are copied as is to the root
27252 file system of the childhurd when it boots. This allows you to
27253 initialize ``secrets'' inside the VM: SSH host keys, authorized
27254 substitute keys, and so on---see the explanation of @code{secret-root}
27257 @defvr {Scheme Variable} hurd-vm-service-type
27258 This is the type of the Hurd in a Virtual Machine service. Its value
27259 must be a @code{hurd-vm-configuration} object, which specifies the
27260 operating system (@pxref{operating-system Reference}) and the disk size
27261 for the Hurd Virtual Machine, the QEMU package to use as well as the
27262 options for running it.
27267 (service hurd-vm-service-type
27268 (hurd-vm-configuration
27269 (disk-size (* 5000 (expt 2 20))) ;5G
27270 (memory-size 1024))) ;1024MiB
27273 would create a disk image big enough to build GNU@tie{}Hello, with some
27277 @deftp {Data Type} hurd-vm-configuration
27278 The data type representing the configuration for
27279 @code{hurd-vm-service-type}.
27282 @item @code{os} (default: @var{%hurd-vm-operating-system})
27283 The operating system to instantiate. This default is bare-bones with a
27284 permissive OpenSSH secure shell daemon listening on port 2222
27285 (@pxref{Networking Services, @code{openssh-service-type}}).
27287 @item @code{qemu} (default: @code{qemu-minimal})
27288 The QEMU package to use.
27290 @item @code{image} (default: @var{hurd-vm-disk-image})
27291 The procedure used to build the disk-image built from this
27294 @item @code{disk-size} (default: @code{'guess})
27295 The size of the disk image.
27297 @item @code{memory-size} (default: @code{512})
27298 The memory size of the Virtual Machine in mebibytes.
27300 @item @code{options} (default: @code{'("--snapshot")})
27301 The extra options for running QEMU.
27303 @item @code{id} (default: @code{#f})
27304 If set, a non-zero positive integer used to parameterize Childhurd
27305 instances. It is appended to the service's name,
27306 e.g. @code{childhurd1}.
27308 @item @code{net-options} (default: @var{hurd-vm-net-options})
27309 The procedure used to produce the list of QEMU networking options.
27311 By default, it produces
27314 '("--device" "rtl8139,netdev=net0"
27315 "--netdev" "user,id=net0\
27316 ,hostfwd=tcp:127.0.0.1:@var{secrets-port}-:1004\
27317 ,hostfwd=tcp:127.0.0.1:@var{ssh-port}-:2222\
27318 ,hostfwd=tcp:127.0.0.1:@var{vnc-port}-:5900")
27321 with forwarded ports:
27324 @var{secrets-port}: @code{(+ 11004 (* 1000 @var{ID}))}
27325 @var{ssh-port}: @code{(+ 10022 (* 1000 @var{ID}))}
27326 @var{vnc-port}: @code{(+ 15900 (* 1000 @var{ID}))}
27329 @item @code{secret-root} (default: @file{/etc/childhurd})
27330 The root directory with out-of-band secrets to be installed into the
27331 childhurd once it runs. Childhurds are volatile which means that on
27332 every startup, secrets such as the SSH host keys and Guix signing key
27335 If the @file{/etc/childhurd} directory does not exist, the
27336 @code{secret-service} running in the Childhurd will be sent an empty
27339 By default, the service automatically populates @file{/etc/childhurd}
27340 with the following non-volatile secrets, unless they already exist:
27343 /etc/childhurd/etc/guix/acl
27344 /etc/childhurd/etc/guix/signing-key.pub
27345 /etc/childhurd/etc/guix/signing-key.sec
27346 /etc/childhurd/etc/ssh/ssh_host_ed25519_key
27347 /etc/childhurd/etc/ssh/ssh_host_ecdsa_key
27348 /etc/childhurd/etc/ssh/ssh_host_ed25519_key.pub
27349 /etc/childhurd/etc/ssh/ssh_host_ecdsa_key.pub
27352 These files are automatically sent to the guest Hurd VM when it boots,
27353 including permissions.
27355 @cindex childhurd, offloading
27356 @cindex Hurd, offloading
27357 Having these files in place means that only a couple of things are
27358 missing to allow the host to offload @code{i586-gnu} builds to the
27363 Authorizing the childhurd's key on the host so that the host accepts
27364 build results coming from the childhurd, which can be done like so:
27367 guix archive --authorize < \
27368 /etc/childhurd/etc/guix/signing-key.pub
27372 Adding the childhurd to @file{/etc/guix/machines.scm} (@pxref{Daemon
27376 We're working towards making that happen automatically---get in touch
27377 with us at @email{guix-devel@@gnu.org} to discuss it!
27381 Note that by default the VM image is volatile, i.e., once stopped the
27382 contents are lost. If you want a stateful image instead, override the
27383 configuration's @code{image} and @code{options} without
27384 the @code{--snapshot} flag using something along these lines:
27387 (service hurd-vm-service-type
27388 (hurd-vm-configuration
27389 (image (const "/out/of/store/writable/hurd.img"))
27393 @subsubheading Ganeti
27398 This service is considered experimental. Configuration options may be changed
27399 in a backwards-incompatible manner, and not all features have been thorougly
27400 tested. Users of this service are encouraged to share their experience at
27401 @email{guix-devel@@gnu.org}.
27404 Ganeti is a virtual machine management system. It is designed to keep virtual
27405 machines running on a cluster of servers even in the event of hardware failures,
27406 and to make maintenance and recovery tasks easy. It consists of multiple
27407 services which are described later in this section. In addition to the Ganeti
27408 service, you will need the OpenSSH service (@pxref{Networking Services,
27409 @code{openssh-service-type}}), and update the @file{/etc/hosts} file
27410 (@pxref{operating-system Reference, @code{hosts-file}}) with the cluster name
27411 and address (or use a DNS server).
27413 All nodes participating in a Ganeti cluster should have the same Ganeti and
27414 @file{/etc/hosts} configuration. Here is an example configuration for a Ganeti
27415 cluster node that supports multiple storage backends, and installs the
27416 @code{debootstrap} and @code{guix} @dfn{OS providers}:
27419 (use-package-modules virtualization)
27420 (use-service-modules base ganeti networking ssh)
27423 (host-name "node1")
27424 (hosts-file (plain-file "hosts" (format #f "
27425 127.0.0.1 localhost
27428 192.168.1.200 ganeti.example.com
27429 192.168.1.201 node1.example.com node1
27430 192.168.1.202 node2.example.com node2
27433 ;; Install QEMU so we can use KVM-based instances, and LVM, DRBD and Ceph
27434 ;; in order to use the "plain", "drbd" and "rbd" storage backends.
27435 (packages (append (map specification->package
27436 '("qemu" "lvm2" "drbd-utils" "ceph"
27437 ;; Add the debootstrap and guix OS providers.
27438 "ganeti-instance-guix" "ganeti-instance-debootstrap"))
27441 (append (list (static-networking-service "eth0" "192.168.1.201"
27442 #:netmask "255.255.255.0"
27443 #:gateway "192.168.1.254"
27444 #:name-servers '("192.168.1.252"
27447 ;; Ganeti uses SSH to communicate between nodes.
27448 (service openssh-service-type
27449 (openssh-configuration
27450 (permit-root-login 'without-password)))
27452 (service ganeti-service-type
27453 (ganeti-configuration
27454 ;; This list specifies allowed file system paths
27455 ;; for storing virtual machine images.
27456 (file-storage-paths '("/srv/ganeti/file-storage"))
27457 ;; This variable configures a single "variant" for
27458 ;; both Debootstrap and Guix that works with KVM.
27459 (os %default-ganeti-os))))
27463 Users are advised to read the
27464 @url{http://docs.ganeti.org/ganeti/master/html/admin.html,Ganeti
27465 administrators guide} to learn about the various cluster options and
27466 day-to-day operations. There is also a
27467 @url{https://guix.gnu.org/blog/2020/running-a-ganeti-cluster-on-guix/,blog post}
27468 describing how to configure and initialize a small cluster.
27470 @defvr {Scheme Variable} ganeti-service-type
27471 This is a service type that includes all the various services that Ganeti
27474 Its value is a @code{ganeti-configuration} object that defines the package
27475 to use for CLI operations, as well as configuration for the various daemons.
27476 Allowed file storage paths and available guest operating systems are also
27477 configured through this data type.
27480 @deftp {Data Type} ganeti-configuration
27481 The @code{ganeti} service takes the following configuration options:
27484 @item @code{ganeti} (default: @code{ganeti})
27485 The @code{ganeti} package to use. It will be installed to the system profile
27486 and make @command{gnt-cluster}, @command{gnt-instance}, etc available. Note
27487 that the value specified here does not affect the other services as each refer
27488 to a specific @code{ganeti} package (see below).
27490 @item @code{noded-configuration} (default: @code{(ganeti-noded-configuration)})
27491 @itemx @code{confd-configuration} (default: @code{(ganeti-confd-configuration)})
27492 @itemx @code{wconfd-configuration} (default: @code{(ganeti-wconfd-configuration)})
27493 @itemx @code{luxid-configuration} (default: @code{(ganeti-luxid-configuration)})
27494 @itemx @code{rapi-configuration} (default: @code{(ganeti-rapi-configuration)})
27495 @itemx @code{kvmd-configuration} (default: @code{(ganeti-kvmd-configuration)})
27496 @itemx @code{mond-configuration} (default: @code{(ganeti-mond-configuration)})
27497 @itemx @code{metad-configuration} (default: @code{(ganeti-metad-configuration)})
27498 @itemx @code{watcher-configuration} (default: @code{(ganeti-watcher-configuration)})
27499 @itemx @code{cleaner-configuration} (default: @code{(ganeti-cleaner-configuration)})
27501 These options control the various daemons and cron jobs that are distributed
27502 with Ganeti. The possible values for these are described in detail below.
27503 To override a setting, you must use the configuration type for that service:
27506 (service ganeti-service-type
27507 (ganeti-configuration
27508 (rapi-configuration
27509 (ganeti-rapi-configuration
27510 (interface "eth1"))))
27511 (watcher-configuration
27512 (ganeti-watcher-configuration
27513 (rapi-ip "10.0.0.1"))))
27516 @item @code{file-storage-paths} (default: @code{'()})
27517 List of allowed directories for file storage backend.
27519 @item @code{os} (default: @code{%default-ganeti-os})
27520 List of @code{<ganeti-os>} records.
27523 In essence @code{ganeti-service-type} is shorthand for declaring each service
27527 (service ganeti-noded-service-type)
27528 (service ganeti-confd-service-type)
27529 (service ganeti-wconfd-service-type)
27530 (service ganeti-luxid-service-type)
27531 (service ganeti-kvmd-service-type)
27532 (service ganeti-mond-service-type)
27533 (service ganeti-metad-service-type)
27534 (service ganeti-watcher-service-type)
27535 (service ganeti-cleaner-service-type)
27538 Plus a service extension for @code{etc-service-type} that configures the file
27539 storage backend and OS variants.
27543 @deftp {Data Type} ganeti-os
27544 This data type is suitable for passing to the @code{os} parameter of
27545 @code{ganeti-configuration}. It takes the following parameters:
27549 The name for this OS provider. It is only used to specify where the
27550 configuration ends up. Setting it to ``debootstrap'' will create
27551 @file{/etc/ganeti/instance-debootstrap}.
27553 @item @code{extension}
27554 The file extension for variants of this OS type. For example
27555 @file{.conf} or @file{.scm}.
27557 @item @code{variants} (default: @code{'()})
27558 List of @code{ganeti-os-variant} objects for this OS.
27563 @deftp {Data Type} ganeti-os-variant
27564 This is the data type for a Ganeti OS variant. It takes the following
27569 The name of this variant.
27571 @item @code{configuration}
27572 A configuration file for this variant.
27576 @defvr {Scheme Variable} %default-debootstrap-hooks
27577 This variable contains hooks to configure networking and the GRUB bootloader.
27580 @defvr {Scheme Variable} %default-debootstrap-extra-pkgs
27581 This variable contains a list of packages suitable for a fully-virtualized guest.
27584 @deftp {Data Type} debootstrap-configuration
27586 This data type creates configuration files suitable for the debootstrap OS provider.
27589 @item @code{hooks} (default: @code{%default-debootstrap-hooks})
27590 When not @code{#f}, this must be a G-expression that specifies a directory with
27591 scripts that will run when the OS is installed. It can also be a list of
27592 @code{(name . file-like)} pairs. For example:
27595 `((99-hello-world . ,(plain-file "#!/bin/sh\necho Hello, World")))
27598 That will create a directory with one executable named @code{99-hello-world}
27599 and run it every time this variant is installed. If set to @code{#f}, hooks
27600 in @file{/etc/ganeti/instance-debootstrap/hooks} will be used, if any.
27601 @item @code{proxy} (default: @code{#f})
27602 Optional HTTP proxy to use.
27603 @item @code{mirror} (default: @code{#f})
27604 The Debian mirror. Typically something like @code{http://ftp.no.debian.org/debian}.
27605 The default varies depending on the distribution.
27606 @item @code{arch} (default: @code{#f})
27607 The dpkg architecture. Set to @code{armhf} to debootstrap an ARMv7 instance
27608 on an AArch64 host. Default is to use the current system architecture.
27609 @item @code{suite} (default: @code{"stable"})
27610 When set, this must be a Debian distribution ``suite'' such as @code{buster}
27611 or @code{focal}. If set to @code{#f}, the default for the OS provider is used.
27612 @item @code{extra-pkgs} (default: @code{%default-debootstrap-extra-pkgs})
27613 List of extra packages that will get installed by dpkg in addition
27614 to the minimal system.
27615 @item @code{components} (default: @code{#f})
27616 When set, must be a list of Debian repository ``components''. For example
27617 @code{'("main" "contrib")}.
27618 @item @code{generate-cache?} (default: @code{#t})
27619 Whether to automatically cache the generated debootstrap archive.
27620 @item @code{clean-cache} (default: @code{14})
27621 Discard the cache after this amount of days. Use @code{#f} to never
27623 @item @code{partition-style} (default: @code{'msdos})
27624 The type of partition to create. When set, it must be one of
27625 @code{'msdos}, @code{'none} or a string.
27626 @item @code{partition-alignment} (default: @code{2048})
27627 Alignment of the partition in sectors.
27631 @deffn {Scheme Procedure} debootstrap-variant @var{name} @var{configuration}
27632 This is a helper procedure that creates a @code{ganeti-os-variant} record. It
27633 takes two parameters: a name and a @code{debootstrap-configuration} object.
27636 @deffn {Scheme Procedure} debootstrap-os @var{variants}@dots{}
27637 This is a helper procedure that creates a @code{ganeti-os} record. It takes
27638 a list of variants created with @code{debootstrap-variant}.
27641 @deffn {Scheme Procedure} guix-variant @var{name} @var{configuration}
27642 This is a helper procedure that creates a @code{ganeti-os-variant} record for
27643 use with the Guix OS provider. It takes a name and a G-expression that returns
27644 a ``file-like'' (@pxref{G-Expressions, file-like objects}) object containing a
27645 Guix System configuration.
27648 @deffn {Scheme Procedure} guix-os @var{variants}@dots{}
27649 This is a helper procedure that creates a @code{ganeti-os} record. It
27650 takes a list of variants produced by @code{guix-variant}.
27653 @defvr {Scheme Variable} %default-debootstrap-variants
27654 This is a convenience variable to make the debootstrap provider work
27655 ``out of the box'' without users having to declare variants manually. It
27656 contains a single debootstrap variant with the default configuration:
27659 (list (debootstrap-variant
27661 (debootstrap-configuration)))
27665 @defvr {Scheme Variable} %default-guix-variants
27666 This is a convenience variable to make the Guix OS provider work without
27667 additional configuration. It creates a virtual machine that has an SSH
27668 server, a serial console, and authorizes the Ganeti hosts SSH keys.
27671 (list (guix-variant
27673 (file-append ganeti-instance-guix
27674 "/share/doc/ganeti-instance-guix/examples/dynamic.scm")))
27678 Users can implement support for OS providers unbeknownst to Guix by extending
27679 the @code{ganeti-os} and @code{ganeti-os-variant} records appropriately.
27685 (extension ".conf")
27687 (list (ganeti-os-variant
27689 (configuration (plain-file "bar" "this is fine"))))))
27692 That creates @file{/etc/ganeti/instance-custom/variants/foo.conf} which points
27693 to a file in the store with contents @code{this is fine}. It also creates
27694 @file{/etc/ganeti/instance-custom/variants/variants.list} with contents @code{foo}.
27696 Obviously this may not work for all OS providers out there. If you find the
27697 interface limiting, please reach out to @email{guix-devel@@gnu.org}.
27699 The rest of this section documents the various services that are included by
27700 @code{ganeti-service-type}.
27702 @defvr {Scheme Variable} ganeti-noded-service-type
27703 @command{ganeti-noded} is the daemon responsible for node-specific functions
27704 within the Ganeti system. The value of this service must be a
27705 @code{ganeti-noded-configuration} object.
27708 @deftp {Data Type} ganeti-noded-configuration
27709 This is the configuration for the @code{ganeti-noded} service.
27712 @item @code{ganeti} (default: @code{ganeti})
27713 The @code{ganeti} package to use for this service.
27715 @item @code{port} (default: @code{1811})
27716 The TCP port on which the node daemon listens for network requests.
27718 @item @code{address} (default: @code{"0.0.0.0"})
27719 The network address that the daemon will bind to. The default address means
27720 bind to all available addresses.
27722 @item @code{interface} (default: @code{#f})
27723 When this is set, it must be a specific network interface (e.g.@: @code{eth0})
27724 that the daemon will bind to.
27726 @item @code{max-clients} (default: @code{20})
27727 This sets a limit on the maximum number of simultaneous client connections
27728 that the daemon will handle. Connections above this count are accepted, but
27729 no responses will be sent until enough connections have closed.
27731 @item @code{ssl?} (default: @code{#t})
27732 Whether to use SSL/TLS to encrypt network communications. The certificate
27733 is automatically provisioned by the cluster and can be rotated with
27734 @command{gnt-cluster renew-crypto}.
27736 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
27737 This can be used to provide a specific encryption key for TLS communications.
27739 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
27740 This can be used to provide a specific certificate for TLS communications.
27742 @item @code{debug?} (default: @code{#f})
27743 When true, the daemon performs additional logging for debugging purposes.
27744 Note that this will leak encryption details to the log files, use with caution.
27749 @defvr {Scheme Variable} ganeti-confd-service-type
27750 @command{ganeti-confd} answers queries related to the configuration of a
27751 Ganeti cluster. The purpose of this daemon is to have a highly available
27752 and fast way to query cluster configuration values. It is automatically
27753 active on all @dfn{master candidates}. The value of this service must be a
27754 @code{ganeti-confd-configuration} object.
27758 @deftp {Data Type} ganeti-confd-configuration
27759 This is the configuration for the @code{ganeti-confd} service.
27762 @item @code{ganeti} (default: @code{ganeti})
27763 The @code{ganeti} package to use for this service.
27765 @item @code{port} (default: @code{1814})
27766 The UDP port on which to listen for network requests.
27768 @item @code{address} (default: @code{"0.0.0.0"})
27769 Network address that the daemon will bind to.
27771 @item @code{debug?} (default: @code{#f})
27772 When true, the daemon performs additional logging for debugging purposes.
27777 @defvr {Scheme Variable} ganeti-wconfd-service-type
27778 @command{ganeti-wconfd} is the daemon that has authoritative knowledge
27779 about the cluster configuration and is the only entity that can accept
27780 changes to it. All jobs that need to modify the configuration will do so
27781 by sending appropriate requests to this daemon. It only runs on the
27782 @dfn{master node} and will automatically disable itself on other nodes.
27784 The value of this service must be a
27785 @code{ganeti-wconfd-configuration} object.
27788 @deftp {Data Type} ganeti-wconfd-configuration
27789 This is the configuration for the @code{ganeti-wconfd} service.
27792 @item @code{ganeti} (default: @code{ganeti})
27793 The @code{ganeti} package to use for this service.
27795 @item @code{no-voting?} (default: @code{#f})
27796 The daemon will refuse to start if the majority of cluster nodes does not
27797 agree that it is running on the master node. Set to @code{#t} to start
27798 even if a quorum can not be reached (dangerous, use with caution).
27800 @item @code{debug?} (default: @code{#f})
27801 When true, the daemon performs additional logging for debugging purposes.
27806 @defvr {Scheme Variable} ganeti-luxid-service-type
27807 @command{ganeti-luxid} is a daemon used to answer queries related to the
27808 configuration and the current live state of a Ganeti cluster. Additionally,
27809 it is the authoritative daemon for the Ganeti job queue. Jobs can be
27810 submitted via this daemon and it schedules and starts them.
27812 It takes a @code{ganeti-luxid-configuration} object.
27815 @deftp {Data Type} ganeti-luxid-configuration
27816 This is the configuration for the @code{ganeti-wconfd} service.
27819 @item @code{ganeti} (default: @code{ganeti})
27820 The @code{ganeti} package to use for this service.
27822 @item @code{no-voting?} (default: @code{#f})
27823 The daemon will refuse to start if it cannot verify that the majority of
27824 cluster nodes believes that it is running on the master node. Set to
27825 @code{#t} to ignore such checks and start anyway (this can be dangerous).
27827 @item @code{debug?} (default: @code{#f})
27828 When true, the daemon performs additional logging for debugging purposes.
27833 @defvr {Scheme Variable} ganeti-rapi-service-type
27834 @command{ganeti-rapi} provides a remote API for Ganeti clusters. It runs on
27835 the master node and can be used to perform cluster actions programmatically
27836 via a JSON-based RPC protocol.
27838 Most query operations are allowed without authentication (unless
27839 @var{require-authentication?} is set), whereas write operations require
27840 explicit authorization via the @file{/var/lib/ganeti/rapi/users} file. See
27841 the @url{http://docs.ganeti.org/ganeti/master/html/rapi.html, Ganeti Remote
27842 API documentation} for more information.
27844 The value of this service must be a @code{ganeti-rapi-configuration} object.
27847 @deftp {Data Type} ganeti-rapi-configuration
27848 This is the configuration for the @code{ganeti-rapi} service.
27851 @item @code{ganeti} (default: @code{ganeti})
27852 The @code{ganeti} package to use for this service.
27854 @item @code{require-authentication?} (default: @code{#f})
27855 Whether to require authentication even for read-only operations.
27857 @item @code{port} (default: @code{5080})
27858 The TCP port on which to listen to API requests.
27860 @item @code{address} (default: @code{"0.0.0.0"})
27861 The network address that the service will bind to. By default it listens
27862 on all configured addresses.
27864 @item @code{interface} (default: @code{#f})
27865 When set, it must specify a specific network interface such as @code{eth0}
27866 that the daemon will bind to.
27868 @item @code{max-clients} (default: @code{20})
27869 The maximum number of simultaneous client requests to handle. Further
27870 connections are allowed, but no responses are sent until enough connections
27873 @item @code{ssl?} (default: @code{#t})
27874 Whether to use SSL/TLS encryption on the RAPI port.
27876 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
27877 This can be used to provide a specific encryption key for TLS communications.
27879 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
27880 This can be used to provide a specific certificate for TLS communications.
27882 @item @code{debug?} (default: @code{#f})
27883 When true, the daemon performs additional logging for debugging purposes.
27884 Note that this will leak encryption details to the log files, use with caution.
27889 @defvr {Scheme Variable} ganeti-kvmd-service-type
27890 @command{ganeti-kvmd} is responsible for determining whether a given KVM
27891 instance was shut down by an administrator or a user. Normally Ganeti will
27892 restart an instance that was not stopped through Ganeti itself. If the
27893 cluster option @code{user_shutdown} is true, this daemon monitors the
27894 @code{QMP} socket provided by QEMU and listens for shutdown events, and
27895 marks the instance as @dfn{USER_down} instead of @dfn{ERROR_down} when
27896 it shuts down gracefully by itself.
27898 It takes a @code{ganeti-kvmd-configuration} object.
27901 @deftp {Data Type} ganeti-kvmd-configuration
27904 @item @code{ganeti} (default: @code{ganeti})
27905 The @code{ganeti} package to use for this service.
27907 @item @code{debug?} (default: @code{#f})
27908 When true, the daemon performs additional logging for debugging purposes.
27913 @defvr {Scheme Variable} ganeti-mond-service-type
27914 @command{ganeti-mond} is an optional daemon that provides Ganeti monitoring
27915 functionality. It is responsible for running data collectors and publish the
27916 collected information through a HTTP interface.
27918 It takes a @code{ganeti-mond-configuration} object.
27921 @deftp {Data Type} ganeti-mond-configuration
27924 @item @code{ganeti} (default: @code{ganeti})
27925 The @code{ganeti} package to use for this service.
27927 @item @code{port} (default: @code{1815})
27928 The port on which the daemon will listen.
27930 @item @code{address} (default: @code{"0.0.0.0"})
27931 The network address that the daemon will bind to. By default it binds to all
27932 available interfaces.
27934 @item @code{debug?} (default: @code{#f})
27935 When true, the daemon performs additional logging for debugging purposes.
27940 @defvr {Scheme Variable} ganeti-metad-service-type
27941 @command{ganeti-metad} is an optional daemon that can be used to provide
27942 information about the cluster to instances or OS install scripts.
27944 It takes a @code{ganeti-metad-configuration} object.
27947 @deftp {Data Type} ganeti-metad-configuration
27950 @item @code{ganeti} (default: @code{ganeti})
27951 The @code{ganeti} package to use for this service.
27953 @item @code{port} (default: @code{80})
27954 The port on which the daemon will listen.
27956 @item @code{address} (default: @code{#f})
27957 If set, the daemon will bind to this address only. If left unset, the behavior
27958 depends on the cluster configuration.
27960 @item @code{debug?} (default: @code{#f})
27961 When true, the daemon performs additional logging for debugging purposes.
27966 @defvr {Scheme Variable} ganeti-watcher-service-type
27967 @command{ganeti-watcher} is a script designed to run periodically and ensure
27968 the health of a cluster. It will automatically restart instances that have
27969 stopped without Ganeti's consent, and repairs DRBD links in case a node has
27970 rebooted. It also archives old cluster jobs and restarts Ganeti daemons
27971 that are not running. If the cluster parameter @code{ensure_node_health}
27972 is set, the watcher will also shutdown instances and DRBD devices if the
27973 node it is running on is declared offline by known master candidates.
27975 It can be paused on all nodes with @command{gnt-cluster watcher pause}.
27977 The service takes a @code{ganeti-watcher-configuration} object.
27980 @deftp {Data Type} ganeti-watcher-configuration
27983 @item @code{ganeti} (default: @code{ganeti})
27984 The @code{ganeti} package to use for this service.
27986 @item @code{schedule} (default: @code{'(next-second-from (next-minute (range 0 60 5)))})
27987 How often to run the script. The default is every five minutes.
27989 @item @code{rapi-ip} (default: @code{#f})
27990 This option needs to be specified only if the RAPI daemon is configured to use
27991 a particular interface or address. By default the cluster address is used.
27993 @item @code{job-age} (default: @code{(* 6 3600)})
27994 Archive cluster jobs older than this age, specified in seconds. The default
27995 is 6 hours. This keeps @command{gnt-job list} manageable.
27997 @item @code{verify-disks?} (default: @code{#t})
27998 If this is @code{#f}, the watcher will not try to repair broken DRBD links
27999 automatically. Administrators will need to use @command{gnt-cluster verify-disks}
28002 @item @code{debug?} (default: @code{#f})
28003 When @code{#t}, the script performs additional logging for debugging purposes.
28008 @defvr {Scheme Variable} ganeti-cleaner-service-type
28009 @command{ganeti-cleaner} is a script designed to run periodically and remove
28010 old files from the cluster. This service type controls two @dfn{cron jobs}:
28011 one intended for the master node that permanently purges old cluster jobs,
28012 and one intended for every node that removes expired X509 certificates, keys,
28013 and outdated @command{ganeti-watcher} information. Like all Ganeti services,
28014 it is safe to include even on non-master nodes as it will disable itself as
28017 It takes a @code{ganeti-cleaner-configuration} object.
28020 @deftp {Data Type} ganeti-cleaner-configuration
28023 @item @code{ganeti} (default: @code{ganeti})
28024 The @code{ganeti} package to use for the @command{gnt-cleaner} command.
28026 @item @code{master-schedule} (default: @code{"45 1 * * *"})
28027 How often to run the master cleaning job. The default is once per day, at
28030 @item @code{node-schedule} (default: @code{"45 2 * * *"})
28031 How often to run the node cleaning job. The default is once per day, at
28037 @node Version Control Services
28038 @subsection Version Control Services
28040 The @code{(gnu services version-control)} module provides a service to
28041 allow remote access to local Git repositories. There are three options:
28042 the @code{git-daemon-service}, which provides access to repositories via
28043 the @code{git://} unsecured TCP-based protocol, extending the
28044 @code{nginx} web server to proxy some requests to
28045 @code{git-http-backend}, or providing a web interface with
28046 @code{cgit-service-type}.
28048 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
28050 Return a service that runs @command{git daemon}, a simple TCP server to
28051 expose repositories over the Git protocol for anonymous access.
28053 The optional @var{config} argument should be a
28054 @code{<git-daemon-configuration>} object, by default it allows read-only
28055 access to exported@footnote{By creating the magic file
28056 @file{git-daemon-export-ok} in the repository directory.} repositories under
28061 @deftp {Data Type} git-daemon-configuration
28062 Data type representing the configuration for @code{git-daemon-service}.
28065 @item @code{package} (default: @code{git})
28066 Package object of the Git distributed version control system.
28068 @item @code{export-all?} (default: @code{#f})
28069 Whether to allow access for all Git repositories, even if they do not
28070 have the @file{git-daemon-export-ok} file.
28072 @item @code{base-path} (default: @file{/srv/git})
28073 Whether to remap all the path requests as relative to the given path.
28074 If you run @command{git daemon} with @code{(base-path "/srv/git")} on
28075 @samp{example.com}, then if you later try to pull
28076 @indicateurl{git://example.com/hello.git}, git daemon will interpret the
28077 path as @file{/srv/git/hello.git}.
28079 @item @code{user-path} (default: @code{#f})
28080 Whether to allow @code{~user} notation to be used in requests. When
28081 specified with empty string, requests to
28082 @indicateurl{git://host/~alice/foo} is taken as a request to access
28083 @code{foo} repository in the home directory of user @code{alice}. If
28084 @code{(user-path "@var{path}")} is specified, the same request is taken
28085 as a request to access @file{@var{path}/foo} repository in the home
28086 directory of user @code{alice}.
28088 @item @code{listen} (default: @code{'()})
28089 Whether to listen on specific IP addresses or hostnames, defaults to
28092 @item @code{port} (default: @code{#f})
28093 Whether to listen on an alternative port, which defaults to 9418.
28095 @item @code{whitelist} (default: @code{'()})
28096 If not empty, only allow access to this list of directories.
28098 @item @code{extra-options} (default: @code{'()})
28099 Extra options will be passed to @command{git daemon}, please run
28100 @command{man git-daemon} for more information.
28105 The @code{git://} protocol lacks authentication. When you pull from a
28106 repository fetched via @code{git://}, you don't know whether the data you
28107 receive was modified or is even coming from the specified host, and your
28108 connection is subject to eavesdropping. It's better to use an authenticated
28109 and encrypted transport, such as @code{https}. Although Git allows you
28110 to serve repositories using unsophisticated file-based web servers,
28111 there is a faster protocol implemented by the @code{git-http-backend}
28112 program. This program is the back-end of a proper Git web service. It
28113 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
28114 on running the necessary @code{fcgiwrap} daemon.
28116 Guix has a separate configuration data type for serving Git repositories
28119 @deftp {Data Type} git-http-configuration
28120 Data type representing the configuration for a future
28121 @code{git-http-service-type}; can currently be used to configure Nginx
28122 through @code{git-http-nginx-location-configuration}.
28125 @item @code{package} (default: @var{git})
28126 Package object of the Git distributed version control system.
28128 @item @code{git-root} (default: @file{/srv/git})
28129 Directory containing the Git repositories to expose to the world.
28131 @item @code{export-all?} (default: @code{#f})
28132 Whether to expose access for all Git repositories in @var{git-root},
28133 even if they do not have the @file{git-daemon-export-ok} file.
28135 @item @code{uri-path} (default: @samp{/git/})
28136 Path prefix for Git access. With the default @samp{/git/} prefix, this
28137 will map @indicateurl{http://@var{server}/git/@var{repo}.git} to
28138 @file{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
28139 with this prefix are not passed on to this Git instance.
28141 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
28142 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
28147 There is no @code{git-http-service-type}, currently; instead you can
28148 create an @code{nginx-location-configuration} from a
28149 @code{git-http-configuration} and then add that location to a web
28152 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
28153 [config=(git-http-configuration)]
28154 Compute an @code{nginx-location-configuration} that corresponds to the
28155 given Git http configuration. An example nginx service definition to
28156 serve the default @file{/srv/git} over HTTPS might be:
28159 (service nginx-service-type
28160 (nginx-configuration
28163 (nginx-server-configuration
28164 (listen '("443 ssl"))
28165 (server-name "git.my-host.org")
28167 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
28168 (ssl-certificate-key
28169 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
28172 (git-http-nginx-location-configuration
28173 (git-http-configuration (uri-path "/"))))))))))
28176 This example assumes that you are using Let's Encrypt to get your TLS
28177 certificate. @xref{Certificate Services}. The default @code{certbot}
28178 service will redirect all HTTP traffic on @code{git.my-host.org} to
28179 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
28180 system services. @xref{Web Services}.
28183 @subsubheading Cgit Service
28185 @cindex Cgit service
28186 @cindex Git, web interface
28187 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
28188 repositories written in C.
28190 The following example will configure the service with default values.
28191 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
28194 (service cgit-service-type)
28197 The @code{file-object} type designates either a file-like object
28198 (@pxref{G-Expressions, file-like objects}) or a string.
28200 @c %start of fragment
28202 Available @code{cgit-configuration} fields are:
28204 @deftypevr {@code{cgit-configuration} parameter} package package
28209 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
28210 NGINX configuration.
28214 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
28215 Specifies a command which will be invoked to format the content of about
28216 pages (both top-level and for each repository).
28218 Defaults to @samp{""}.
28222 @deftypevr {@code{cgit-configuration} parameter} string agefile
28223 Specifies a path, relative to each repository path, which can be used to
28224 specify the date and time of the youngest commit in the repository.
28226 Defaults to @samp{""}.
28230 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
28231 Specifies a command that will be invoked for authenticating repository
28234 Defaults to @samp{""}.
28238 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
28239 Flag which, when set to @samp{age}, enables date ordering in the branch
28240 ref list, and when set @samp{name} enables ordering by branch name.
28242 Defaults to @samp{"name"}.
28246 @deftypevr {@code{cgit-configuration} parameter} string cache-root
28247 Path used to store the cgit cache entries.
28249 Defaults to @samp{"/var/cache/cgit"}.
28253 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
28254 Number which specifies the time-to-live, in minutes, for the cached
28255 version of repository pages accessed with a fixed SHA1.
28257 Defaults to @samp{-1}.
28261 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
28262 Number which specifies the time-to-live, in minutes, for the cached
28263 version of repository pages accessed without a fixed SHA1.
28265 Defaults to @samp{5}.
28269 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
28270 Number which specifies the time-to-live, in minutes, for the cached
28271 version of the repository summary page.
28273 Defaults to @samp{5}.
28277 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
28278 Number which specifies the time-to-live, in minutes, for the cached
28279 version of the repository index page.
28281 Defaults to @samp{5}.
28285 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
28286 Number which specifies the time-to-live, in minutes, for the result of
28287 scanning a path for Git repositories.
28289 Defaults to @samp{15}.
28293 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
28294 Number which specifies the time-to-live, in minutes, for the cached
28295 version of the repository about page.
28297 Defaults to @samp{15}.
28301 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
28302 Number which specifies the time-to-live, in minutes, for the cached
28303 version of snapshots.
28305 Defaults to @samp{5}.
28309 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
28310 The maximum number of entries in the cgit cache. When set to @samp{0},
28311 caching is disabled.
28313 Defaults to @samp{0}.
28317 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
28318 Sort items in the repo list case sensitively.
28320 Defaults to @samp{#t}.
28324 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
28325 List of common prefixes which, when combined with a repository URL,
28326 generates valid clone URLs for the repository.
28328 Defaults to @samp{()}.
28332 @deftypevr {@code{cgit-configuration} parameter} list clone-url
28333 List of @code{clone-url} templates.
28335 Defaults to @samp{()}.
28339 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
28340 Command which will be invoked to format commit messages.
28342 Defaults to @samp{""}.
28346 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
28347 Flag which, when set to @samp{date}, enables strict date ordering in the
28348 commit log, and when set to @samp{topo} enables strict topological
28351 Defaults to @samp{"git log"}.
28355 @deftypevr {@code{cgit-configuration} parameter} file-object css
28356 URL which specifies the css document to include in all cgit pages.
28358 Defaults to @samp{"/share/cgit/cgit.css"}.
28362 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
28363 Specifies a command which will be invoked to format names and email
28364 address of committers, authors, and taggers, as represented in various
28365 places throughout the cgit interface.
28367 Defaults to @samp{""}.
28371 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
28372 Flag which, when set to @samp{#t}, will make cgit generate a HTML
28373 fragment suitable for embedding in other HTML pages.
28375 Defaults to @samp{#f}.
28379 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
28380 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
28381 commit history graph to the left of the commit messages in the
28382 repository log page.
28384 Defaults to @samp{#f}.
28388 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
28389 Flag which, when set to @samp{#t}, allows all filter settings to be
28390 overridden in repository-specific cgitrc files.
28392 Defaults to @samp{#f}.
28396 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
28397 Flag which, when set to @samp{#t}, allows users to follow a file in the
28400 Defaults to @samp{#f}.
28404 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
28405 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
28408 Defaults to @samp{#t}.
28412 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
28413 Flag which, when set to @samp{#t}, will make cgit generate extra links
28414 "summary", "commit", "tree" for each repo in the repository index.
28416 Defaults to @samp{#f}.
28420 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
28421 Flag which, when set to @samp{#t}, will make cgit display the owner of
28422 each repo in the repository index.
28424 Defaults to @samp{#t}.
28428 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
28429 Flag which, when set to @samp{#t}, will make cgit print the number of
28430 modified files for each commit on the repository log page.
28432 Defaults to @samp{#f}.
28436 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
28437 Flag which, when set to @samp{#t}, will make cgit print the number of
28438 added and removed lines for each commit on the repository log page.
28440 Defaults to @samp{#f}.
28444 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
28445 Flag which, when set to @code{#t}, will make cgit display remote
28446 branches in the summary and refs views.
28448 Defaults to @samp{#f}.
28452 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
28453 Flag which, when set to @code{1}, will make cgit use the subject of the
28454 parent commit as link text when generating links to parent commits in
28457 Defaults to @samp{#f}.
28461 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
28462 Flag which, when set to @samp{#t}, will make cgit use the subject of the
28463 parent commit as link text when generating links to parent commits in
28466 Defaults to @samp{#f}.
28470 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
28471 Flag which, when set to @samp{#t}, will make cgit generate linenumber
28472 links for plaintext blobs printed in the tree view.
28474 Defaults to @samp{#t}.
28478 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
28479 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
28480 set any repo specific settings.
28482 Defaults to @samp{#f}.
28486 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
28487 URL used as link to a shortcut icon for cgit.
28489 Defaults to @samp{"/favicon.ico"}.
28493 @deftypevr {@code{cgit-configuration} parameter} string footer
28494 The content of the file specified with this option will be included
28495 verbatim at the bottom of all pages (i.e.@: it replaces the standard
28496 "generated by..."@: message).
28498 Defaults to @samp{""}.
28502 @deftypevr {@code{cgit-configuration} parameter} string head-include
28503 The content of the file specified with this option will be included
28504 verbatim in the HTML HEAD section on all pages.
28506 Defaults to @samp{""}.
28510 @deftypevr {@code{cgit-configuration} parameter} string header
28511 The content of the file specified with this option will be included
28512 verbatim at the top of all pages.
28514 Defaults to @samp{""}.
28518 @deftypevr {@code{cgit-configuration} parameter} file-object include
28519 Name of a configfile to include before the rest of the current config-
28522 Defaults to @samp{""}.
28526 @deftypevr {@code{cgit-configuration} parameter} string index-header
28527 The content of the file specified with this option will be included
28528 verbatim above the repository index.
28530 Defaults to @samp{""}.
28534 @deftypevr {@code{cgit-configuration} parameter} string index-info
28535 The content of the file specified with this option will be included
28536 verbatim below the heading on the repository index page.
28538 Defaults to @samp{""}.
28542 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
28543 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
28544 in the servers timezone.
28546 Defaults to @samp{#f}.
28550 @deftypevr {@code{cgit-configuration} parameter} file-object logo
28551 URL which specifies the source of an image which will be used as a logo
28554 Defaults to @samp{"/share/cgit/cgit.png"}.
28558 @deftypevr {@code{cgit-configuration} parameter} string logo-link
28559 URL loaded when clicking on the cgit logo image.
28561 Defaults to @samp{""}.
28565 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
28566 Command which will be invoked to format the Owner column of the main
28569 Defaults to @samp{""}.
28573 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
28574 Number of items to display in atom feeds view.
28576 Defaults to @samp{10}.
28580 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
28581 Number of entries to list per page in "log" view.
28583 Defaults to @samp{50}.
28587 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
28588 Number of commit message characters to display in "log" view.
28590 Defaults to @samp{80}.
28594 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
28595 Specifies the number of entries to list per page on the repository index
28598 Defaults to @samp{50}.
28602 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
28603 Specifies the maximum number of repo description characters to display
28604 on the repository index page.
28606 Defaults to @samp{80}.
28610 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
28611 Specifies the maximum size of a blob to display HTML for in KBytes.
28613 Defaults to @samp{0}.
28617 @deftypevr {@code{cgit-configuration} parameter} string max-stats
28618 Maximum statistics period. Valid values are @samp{week},@samp{month},
28619 @samp{quarter} and @samp{year}.
28621 Defaults to @samp{""}.
28625 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
28626 Mimetype for the specified filename extension.
28628 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
28629 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
28630 "image/png") (svg "image/svg+xml"))}.
28634 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
28635 Specifies the file to use for automatic mimetype lookup.
28637 Defaults to @samp{""}.
28641 @deftypevr {@code{cgit-configuration} parameter} string module-link
28642 Text which will be used as the formatstring for a hyperlink when a
28643 submodule is printed in a directory listing.
28645 Defaults to @samp{""}.
28649 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
28650 If set to the value @samp{#t} caching will be disabled.
28652 Defaults to @samp{#f}.
28656 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
28657 If set to @samp{#t} showing full author email addresses will be
28660 Defaults to @samp{#f}.
28664 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
28665 Flag which, when set to @samp{#t}, will make cgit omit the standard
28666 header on all pages.
28668 Defaults to @samp{#f}.
28672 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
28673 A list of subdirectories inside of @code{repository-directory}, relative
28674 to it, that should loaded as Git repositories. An empty list means that
28675 all subdirectories will be loaded.
28677 Defaults to @samp{()}.
28681 @deftypevr {@code{cgit-configuration} parameter} file-object readme
28682 Text which will be used as default value for @code{cgit-repo-readme}.
28684 Defaults to @samp{""}.
28688 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
28689 If set to @code{#t} and @code{repository-directory} is enabled, if any
28690 repositories are found with a suffix of @code{.git}, this suffix will be
28691 removed for the URL and name.
28693 Defaults to @samp{#f}.
28697 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
28698 Maximum number of files to consider when detecting renames.
28700 Defaults to @samp{-1}.
28704 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
28705 The way in which repositories in each section are sorted.
28707 Defaults to @samp{""}.
28711 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
28712 Text used as content for the @code{robots} meta-tag.
28714 Defaults to @samp{("noindex" "nofollow")}.
28718 @deftypevr {@code{cgit-configuration} parameter} string root-desc
28719 Text printed below the heading on the repository index page.
28721 Defaults to @samp{"a fast webinterface for the git dscm"}.
28725 @deftypevr {@code{cgit-configuration} parameter} string root-readme
28726 The content of the file specified with this option will be included
28727 verbatim below the ``about'' link on the repository index page.
28729 Defaults to @samp{""}.
28733 @deftypevr {@code{cgit-configuration} parameter} string root-title
28734 Text printed as heading on the repository index page.
28736 Defaults to @samp{""}.
28740 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
28741 If set to @samp{#t} and repository-directory is enabled,
28742 repository-directory will recurse into directories whose name starts
28743 with a period. Otherwise, repository-directory will stay away from such
28744 directories, considered as ``hidden''. Note that this does not apply to
28745 the @file{.git} directory in non-bare repos.
28747 Defaults to @samp{#f}.
28751 @deftypevr {@code{cgit-configuration} parameter} list snapshots
28752 Text which specifies the default set of snapshot formats that cgit
28753 generates links for.
28755 Defaults to @samp{()}.
28759 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
28760 Name of the directory to scan for repositories (represents
28763 Defaults to @samp{"/srv/git"}.
28767 @deftypevr {@code{cgit-configuration} parameter} string section
28768 The name of the current repository section - all repositories defined
28769 after this option will inherit the current section name.
28771 Defaults to @samp{""}.
28775 @deftypevr {@code{cgit-configuration} parameter} string section-sort
28776 Flag which, when set to @samp{1}, will sort the sections on the
28777 repository listing by name.
28779 Defaults to @samp{""}.
28783 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
28784 A number which, if defined prior to repository-directory, specifies how
28785 many path elements from each repo path to use as a default section name.
28787 Defaults to @samp{0}.
28791 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
28792 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
28795 Defaults to @samp{#f}.
28799 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
28800 Specifies a command which will be invoked to format plaintext blobs in
28803 Defaults to @samp{""}.
28807 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
28808 Specifies the number of branches to display in the repository ``summary''
28811 Defaults to @samp{10}.
28815 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
28816 Specifies the number of log entries to display in the repository
28819 Defaults to @samp{10}.
28823 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
28824 Specifies the number of tags to display in the repository ``summary''
28827 Defaults to @samp{10}.
28831 @deftypevr {@code{cgit-configuration} parameter} string strict-export
28832 Filename which, if specified, needs to be present within the repository
28833 for cgit to allow access to that repository.
28835 Defaults to @samp{""}.
28839 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
28840 URL which, if specified, will be used as root for all cgit links.
28842 Defaults to @samp{"/"}.
28846 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
28847 A list of @dfn{cgit-repo} records to use with config.
28849 Defaults to @samp{()}.
28851 Available @code{repository-cgit-configuration} fields are:
28853 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
28854 A mask of snapshot formats for this repo that cgit generates links for,
28855 restricted by the global @code{snapshots} setting.
28857 Defaults to @samp{()}.
28861 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
28862 Override the default @code{source-filter}.
28864 Defaults to @samp{""}.
28868 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
28869 The relative URL used to access the repository.
28871 Defaults to @samp{""}.
28875 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
28876 Override the default @code{about-filter}.
28878 Defaults to @samp{""}.
28882 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
28883 Flag which, when set to @samp{age}, enables date ordering in the branch
28884 ref list, and when set to @samp{name} enables ordering by branch name.
28886 Defaults to @samp{""}.
28890 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
28891 A list of URLs which can be used to clone repo.
28893 Defaults to @samp{()}.
28897 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
28898 Override the default @code{commit-filter}.
28900 Defaults to @samp{""}.
28904 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
28905 Flag which, when set to @samp{date}, enables strict date ordering in the
28906 commit log, and when set to @samp{topo} enables strict topological
28909 Defaults to @samp{""}.
28913 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
28914 The name of the default branch for this repository. If no such branch
28915 exists in the repository, the first branch name (when sorted) is used as
28916 default instead. By default branch pointed to by HEAD, or ``master'' if
28917 there is no suitable HEAD.
28919 Defaults to @samp{""}.
28923 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
28924 The value to show as repository description.
28926 Defaults to @samp{""}.
28930 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
28931 The value to show as repository homepage.
28933 Defaults to @samp{""}.
28937 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
28938 Override the default @code{email-filter}.
28940 Defaults to @samp{""}.
28944 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
28945 A flag which can be used to disable the global setting
28946 @code{enable-commit-graph?}.
28948 Defaults to @samp{disabled}.
28952 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
28953 A flag which can be used to disable the global setting
28954 @code{enable-log-filecount?}.
28956 Defaults to @samp{disabled}.
28960 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
28961 A flag which can be used to disable the global setting
28962 @code{enable-log-linecount?}.
28964 Defaults to @samp{disabled}.
28968 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
28969 Flag which, when set to @code{#t}, will make cgit display remote
28970 branches in the summary and refs views.
28972 Defaults to @samp{disabled}.
28976 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
28977 A flag which can be used to override the global setting
28978 @code{enable-subject-links?}.
28980 Defaults to @samp{disabled}.
28984 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
28985 A flag which can be used to override the global setting
28986 @code{enable-html-serving?}.
28988 Defaults to @samp{disabled}.
28992 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
28993 Flag which, when set to @code{#t}, hides the repository from the
28996 Defaults to @samp{#f}.
29000 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
29001 Flag which, when set to @samp{#t}, ignores the repository.
29003 Defaults to @samp{#f}.
29007 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
29008 URL which specifies the source of an image which will be used as a logo
29009 on this repo’s pages.
29011 Defaults to @samp{""}.
29015 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
29016 URL loaded when clicking on the cgit logo image.
29018 Defaults to @samp{""}.
29022 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
29023 Override the default @code{owner-filter}.
29025 Defaults to @samp{""}.
29029 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
29030 Text which will be used as the formatstring for a hyperlink when a
29031 submodule is printed in a directory listing. The arguments for the
29032 formatstring are the path and SHA1 of the submodule commit.
29034 Defaults to @samp{""}.
29038 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
29039 Text which will be used as the formatstring for a hyperlink when a
29040 submodule with the specified subdirectory path is printed in a directory
29043 Defaults to @samp{()}.
29047 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
29048 Override the default maximum statistics period.
29050 Defaults to @samp{""}.
29054 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
29055 The value to show as repository name.
29057 Defaults to @samp{""}.
29061 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
29062 A value used to identify the owner of the repository.
29064 Defaults to @samp{""}.
29068 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
29069 An absolute path to the repository directory.
29071 Defaults to @samp{""}.
29075 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
29076 A path (relative to repo) which specifies a file to include verbatim as
29077 the ``About'' page for this repo.
29079 Defaults to @samp{""}.
29083 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
29084 The name of the current repository section - all repositories defined
29085 after this option will inherit the current section name.
29087 Defaults to @samp{""}.
29091 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
29092 Extra options will be appended to cgitrc file.
29094 Defaults to @samp{()}.
29100 @deftypevr {@code{cgit-configuration} parameter} list extra-options
29101 Extra options will be appended to cgitrc file.
29103 Defaults to @samp{()}.
29108 @c %end of fragment
29110 However, it could be that you just want to get a @code{cgitrc} up and
29111 running. In that case, you can pass an @code{opaque-cgit-configuration}
29112 as a record to @code{cgit-service-type}. As its name indicates, an
29113 opaque configuration does not have easy reflective capabilities.
29115 Available @code{opaque-cgit-configuration} fields are:
29117 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
29121 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
29122 The contents of the @code{cgitrc}, as a string.
29125 For example, if your @code{cgitrc} is just the empty string, you
29126 could instantiate a cgit service like this:
29129 (service cgit-service-type
29130 (opaque-cgit-configuration
29134 @subsubheading Gitolite Service
29136 @cindex Gitolite service
29137 @cindex Git, hosting
29138 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
29139 repositories on a central server.
29141 Gitolite can handle multiple repositories and users, and supports flexible
29142 configuration of the permissions for the users on the repositories.
29144 The following example will configure Gitolite using the default @code{git}
29145 user, and the provided SSH public key.
29148 (service gitolite-service-type
29149 (gitolite-configuration
29150 (admin-pubkey (plain-file
29152 "ssh-rsa AAAA... guix@@example.com"))))
29155 Gitolite is configured through a special admin repository which you can clone,
29156 for example, if you setup Gitolite on @code{example.com}, you would run the
29157 following command to clone the admin repository.
29160 git clone git@@example.com:gitolite-admin
29163 When the Gitolite service is activated, the provided @code{admin-pubkey} will
29164 be inserted in to the @file{keydir} directory in the gitolite-admin
29165 repository. If this results in a change in the repository, it will be
29166 committed using the message ``gitolite setup by GNU Guix''.
29168 @deftp {Data Type} gitolite-configuration
29169 Data type representing the configuration for @code{gitolite-service-type}.
29172 @item @code{package} (default: @var{gitolite})
29173 Gitolite package to use.
29175 @item @code{user} (default: @var{git})
29176 User to use for Gitolite. This will be user that you use when accessing
29179 @item @code{group} (default: @var{git})
29180 Group to use for Gitolite.
29182 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
29183 Directory in which to store the Gitolite configuration and repositories.
29185 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
29186 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
29187 representing the configuration for Gitolite.
29189 @item @code{admin-pubkey} (default: @var{#f})
29190 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
29191 setup Gitolite. This will be inserted in to the @file{keydir} directory
29192 within the gitolite-admin repository.
29194 To specify the SSH key as a string, use the @code{plain-file} function.
29197 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
29203 @deftp {Data Type} gitolite-rc-file
29204 Data type representing the Gitolite RC file.
29207 @item @code{umask} (default: @code{#o0077})
29208 This controls the permissions Gitolite sets on the repositories and their
29211 A value like @code{#o0027} will give read access to the group used by Gitolite
29212 (by default: @code{git}). This is necessary when using Gitolite with software
29213 like cgit or gitweb.
29215 @item @code{git-config-keys} (default: @code{""})
29216 Gitolite allows you to set git config values using the @samp{config} keyword. This
29217 setting allows control over the config keys to accept.
29219 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
29220 Set the role names allowed to be used by users running the perms command.
29222 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
29223 This setting controls the commands and features to enable within Gitolite.
29229 @node Game Services
29230 @subsection Game Services
29232 @subsubheading The Battle for Wesnoth Service
29234 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
29235 based tactical strategy game, with several single player campaigns, and
29236 multiplayer games (both networked and local).
29238 @defvar {Scheme Variable} wesnothd-service-type
29239 Service type for the wesnothd service. Its value must be a
29240 @code{wesnothd-configuration} object. To run wesnothd in the default
29241 configuration, instantiate it as:
29244 (service wesnothd-service-type)
29248 @deftp {Data Type} wesnothd-configuration
29249 Data type representing the configuration of @command{wesnothd}.
29252 @item @code{package} (default: @code{wesnoth-server})
29253 The wesnoth server package to use.
29255 @item @code{port} (default: @code{15000})
29256 The port to bind the server to.
29261 @node PAM Mount Service
29262 @subsection PAM Mount Service
29265 The @code{(gnu services pam-mount)} module provides a service allowing
29266 users to mount volumes when they log in. It should be able to mount any
29267 volume format supported by the system.
29269 @defvar {Scheme Variable} pam-mount-service-type
29270 Service type for PAM Mount support.
29273 @deftp {Data Type} pam-mount-configuration
29274 Data type representing the configuration of PAM Mount.
29276 It takes the following parameters:
29280 The configuration rules that will be used to generate
29281 @file{/etc/security/pam_mount.conf.xml}.
29283 The configuration rules are SXML elements (@pxref{SXML,,, guile, GNU
29284 Guile Reference Manual}), and the default ones don't mount anything for
29288 `((debug (@@ (enable "0")))
29289 (mntoptions (@@ (allow ,(string-join
29290 '("nosuid" "nodev" "loop"
29291 "encryption" "fsck" "nonempty"
29292 "allow_root" "allow_other")
29294 (mntoptions (@@ (require "nosuid,nodev")))
29295 (logout (@@ (wait "0")
29299 (mkmountpoint (@@ (enable "1")
29303 Some @code{volume} elements must be added to automatically mount volumes
29304 at login. Here's an example allowing the user @code{alice} to mount her
29305 encrypted @env{HOME} directory and allowing the user @code{bob} to mount
29306 the partition where he stores his data:
29309 (define pam-mount-rules
29310 `((debug (@@ (enable "0")))
29311 (volume (@@ (user "alice")
29314 (mountpoint "/home/alice")))
29315 (volume (@@ (user "bob")
29318 (mountpoint "/home/bob/data")
29319 (options "defaults,autodefrag,compress")))
29320 (mntoptions (@@ (allow ,(string-join
29321 '("nosuid" "nodev" "loop"
29322 "encryption" "fsck" "nonempty"
29323 "allow_root" "allow_other")
29325 (mntoptions (@@ (require "nosuid,nodev")))
29326 (logout (@@ (wait "0")
29330 (mkmountpoint (@@ (enable "1")
29331 (remove "true")))))
29333 (service pam-mount-service-type
29334 (pam-mount-configuration
29335 (rules pam-mount-rules)))
29338 The complete list of possible options can be found in the man page for
29339 @uref{http://pam-mount.sourceforge.net/pam_mount.conf.5.html, pam_mount.conf}.
29344 @node Guix Services
29345 @subsection Guix Services
29347 @subsubheading Guix Build Coordinator
29348 The @uref{https://git.cbaines.net/guix/build-coordinator/,Guix Build
29349 Coordinator} aids in distributing derivation builds among machines
29350 running an @dfn{agent}. The build daemon is still used to build the
29351 derivations, but the Guix Build Coordinator manages allocating builds
29352 and working with the results.
29355 This service is considered experimental. Configuration options may be
29356 changed in a backwards-incompatible manner, and not all features have
29357 been thorougly tested.
29360 The Guix Build Coordinator consists of one @dfn{coordinator}, and one or
29361 more connected @dfn{agent} processes. The coordinator process handles
29362 clients submitting builds, and allocating builds to agents. The agent
29363 processes talk to a build daemon to actually perform the builds, then
29364 send the results back to the coordinator.
29366 There is a script to run the coordinator component of the Guix Build
29367 Coordinator, but the Guix service uses a custom Guile script instead, to
29368 provide better integration with G-expressions used in the configuration.
29370 @defvar {Scheme Variable} guix-build-coordinator-service-type
29371 Service type for the Guix Build Coordinator. Its value must be a
29372 @code{guix-build-coordinator-configuration} object.
29375 @deftp {Data Type} guix-build-coordinator-configuration
29376 Data type representing the configuration of the Guix Build Coordinator.
29379 @item @code{package} (default: @code{guix-build-coordinator})
29380 The Guix Build Coordinator package to use.
29382 @item @code{user} (default: @code{"guix-build-coordinator"})
29383 The system user to run the service as.
29385 @item @code{group} (default: @code{"guix-build-coordinator"})
29386 The system group to run the service as.
29388 @item @code{database-uri-string} (default: @code{"sqlite:///var/lib/guix-build-coordinator/guix_build_coordinator.db"})
29389 The URI to use for the database.
29391 @item @code{agent-communication-uri} (default: @code{"http://0.0.0.0:8745"})
29392 The URI describing how to listen to requests from agent processes.
29394 @item @code{client-communication-uri} (default: @code{"http://127.0.0.1:8746"})
29395 The URI describing how to listen to requests from clients. The client
29396 API allows submitting builds and currently isn't authenticated, so take
29397 care when configuring this value.
29399 @item @code{allocation-strategy} (default: @code{#~basic-build-allocation-strategy})
29400 A G-expression for the allocation strategy to be used. This is a
29401 procedure that takes the datastore as an argument and populates the
29402 allocation plan in the database.
29404 @item @code{hooks} (default: @var{'()})
29405 An association list of hooks. These provide a way to execute arbitrary
29406 code upon certain events, like a build result being processed.
29408 @item @code{guile} (default: @code{guile-3.0-latest})
29409 The Guile package with which to run the Guix Build Coordinator.
29414 @defvar {Scheme Variable} guix-build-coordinator-agent-service-type
29415 Service type for a Guix Build Coordinator agent. Its value must be a
29416 @code{guix-build-coordinator-agent-configuration} object.
29419 @deftp {Data Type} guix-build-coordinator-agent-configuration
29420 Data type representing the configuration a Guix Build Coordinator agent.
29423 @item @code{package} (default: @code{guix-build-coordinator})
29424 The Guix Build Coordinator package to use.
29426 @item @code{user} (default: @code{"guix-build-coordinator-agent"})
29427 The system user to run the service as.
29429 @item @code{coordinator} (default: @code{"http://localhost:8745"})
29430 The URI to use when connecting to the coordinator.
29433 The UUID of the agent. This should be generated by the coordinator
29434 process, stored in the coordinator database, and used by the intended
29437 @item @code{password} (default: @code{#f})
29438 The password to use when connecting to the coordinator. A file to read
29439 the password from can also be specified, and this is more secure.
29441 @item @code{password-file} (default: @code{#f})
29442 A file containing the password to use when connecting to the
29445 @item @code{systems} (default: @code{#f})
29446 The systems for which this agent should fetch builds. The agent process
29447 will use the current system it's running on as the default.
29449 @item @code{max-parallel-builds} (default: @code{1})
29450 The number of builds to perform in parallel.
29452 @item @code{derivation-substitute-urls} (default: @code{#f})
29453 URLs from which to attempt to fetch substitutes for derivations, if the
29454 derivations aren't already available.
29456 @item @code{non-derivation-substitute-urls} (default: @code{#f})
29457 URLs from which to attempt to fetch substitutes for build inputs, if the
29458 input store items aren't already available.
29463 The Guix Build Coordinator package contains a script to query an
29464 instance of the Guix Data Service for derivations to build, and then
29465 submit builds for those derivations to the coordinator. The service
29466 type below assists in running this script. This is an additional tool
29467 that may be useful when building derivations contained within an
29468 instance of the Guix Data Service.
29470 @defvar {Scheme Variable} guix-build-coordinator-queue-builds-service-type
29471 Service type for the
29472 guix-build-coordinator-queue-builds-from-guix-data-service script. Its
29473 value must be a @code{guix-build-coordinator-queue-builds-configuration}
29477 @deftp {Data Type} guix-build-coordinator-queue-builds-configuration
29478 Data type representing the options to the queue builds from guix data
29482 @item @code{package} (default: @code{guix-build-coordinator})
29483 The Guix Build Coordinator package to use.
29485 @item @code{user} (default: @code{"guix-build-coordinator-queue-builds"})
29486 The system user to run the service as.
29488 @item @code{coordinator} (default: @code{"http://localhost:8745"})
29489 The URI to use when connecting to the coordinator.
29491 @item @code{systems} (default: @code{#f})
29492 The systems for which to fetch derivations to build.
29494 @item @code{systems-and-targets} (default: @code{#f})
29495 An association list of system and target pairs for which to fetch
29496 derivations to build.
29498 @item @code{guix-data-service} (default: @code{"https://data.guix.gnu.org"})
29499 The Guix Data Service instance from which to query to find out about
29500 derivations to build.
29502 @item @code{processed-commits-file} (default: @code{"/var/cache/guix-build-coordinator-queue-builds/processed-commits"})
29503 A file to record which commits have been processed, to avoid needlessly
29504 processing them again if the service is restarted.
29509 @subsubheading Guix Data Service
29510 The @uref{http://data.guix.gnu.org,Guix Data Service} processes, stores
29511 and provides data about GNU Guix. This includes information about
29512 packages, derivations and lint warnings.
29514 The data is stored in a PostgreSQL database, and available through a web
29517 @defvar {Scheme Variable} guix-data-service-type
29518 Service type for the Guix Data Service. Its value must be a
29519 @code{guix-data-service-configuration} object. The service optionally
29520 extends the getmail service, as the guix-commits mailing list is used to
29521 find out about changes in the Guix git repository.
29524 @deftp {Data Type} guix-data-service-configuration
29525 Data type representing the configuration of the Guix Data Service.
29528 @item @code{package} (default: @code{guix-data-service})
29529 The Guix Data Service package to use.
29531 @item @code{user} (default: @code{"guix-data-service"})
29532 The system user to run the service as.
29534 @item @code{group} (default: @code{"guix-data-service"})
29535 The system group to run the service as.
29537 @item @code{port} (default: @code{8765})
29538 The port to bind the web service to.
29540 @item @code{host} (default: @code{"127.0.0.1"})
29541 The host to bind the web service to.
29543 @item @code{getmail-idle-mailboxes} (default: @code{#f})
29544 If set, this is the list of mailboxes that the getmail service will be
29545 configured to listen to.
29547 @item @code{commits-getmail-retriever-configuration} (default: @code{#f})
29548 If set, this is the @code{getmail-retriever-configuration} object with
29549 which to configure getmail to fetch mail from the guix-commits mailing
29552 @item @code{extra-options} (default: @var{'()})
29553 Extra command line options for @code{guix-data-service}.
29555 @item @code{extra-process-jobs-options} (default: @var{'()})
29556 Extra command line options for @code{guix-data-service-process-jobs}.
29561 @node Linux Services
29562 @subsection Linux Services
29565 @cindex out of memory killer
29567 @cindex early out of memory daemon
29568 @subsubheading Early OOM Service
29570 @uref{https://github.com/rfjakob/earlyoom,Early OOM}, also known as
29571 Earlyoom, is a minimalist out of memory (OOM) daemon that runs in user
29572 space and provides a more responsive and configurable alternative to the
29573 in-kernel OOM killer. It is useful to prevent the system from becoming
29574 unresponsive when it runs out of memory.
29576 @deffn {Scheme Variable} earlyoom-service-type
29577 The service type for running @command{earlyoom}, the Early OOM daemon.
29578 Its value must be a @code{earlyoom-configuration} object, described
29579 below. The service can be instantiated in its default configuration
29583 (service earlyoom-service-type)
29587 @deftp {Data Type} earlyoom-configuration
29588 This is the configuration record for the @code{earlyoom-service-type}.
29591 @item @code{earlyoom} (default: @var{earlyoom})
29592 The Earlyoom package to use.
29594 @item @code{minimum-available-memory} (default: @code{10})
29595 The threshold for the minimum @emph{available} memory, in percentages.
29597 @item @code{minimum-free-swap} (default: @code{10})
29598 The threshold for the minimum free swap memory, in percentages.
29600 @item @code{prefer-regexp} (default: @code{#f})
29601 A regular expression (as a string) to match the names of the processes
29602 that should be preferably killed.
29604 @item @code{avoid-regexp} (default: @code{#f})
29605 A regular expression (as a string) to match the names of the processes
29606 that should @emph{not} be killed.
29608 @item @code{memory-report-interval} (default: @code{0})
29609 The interval in seconds at which a memory report is printed. It is
29610 disabled by default.
29612 @item @code{ignore-positive-oom-score-adj?} (default: @code{#f})
29613 A boolean indicating whether the positive adjustments set in
29614 @file{/proc/*/oom_score_adj} should be ignored.
29616 @item @code{show-debug-messages?} (default: @code{#f})
29617 A boolean indicating whether debug messages should be printed. The logs
29618 are saved at @file{/var/log/earlyoom.log}.
29620 @item @code{send-notification-command} (default: @code{#f})
29621 This can be used to provide a custom command used for sending
29627 @cindex kernel module loader
29628 @subsubheading Kernel Module Loader Service
29630 The kernel module loader service allows one to load loadable kernel
29631 modules at boot. This is especially useful for modules that don't
29632 autoload and need to be manually loaded, as it's the case with
29635 @deffn {Scheme Variable} kernel-module-loader-service-type
29636 The service type for loading loadable kernel modules at boot with
29637 @command{modprobe}. Its value must be a list of strings representing
29638 module names. For example loading the drivers provided by
29639 @code{ddcci-driver-linux}, in debugging mode by passing some module
29640 parameters, can be done as follow:
29643 (use-modules (gnu) (gnu services))
29644 (use-package-modules linux)
29645 (use-service-modules linux)
29647 (define ddcci-config
29648 (plain-file "ddcci.conf"
29649 "options ddcci dyndbg delay=120"))
29653 (services (cons* (service kernel-module-loader-service-type
29654 '("ddcci" "ddcci_backlight"))
29655 (simple-service 'ddcci-config etc-service-type
29656 (list `("modprobe.d/ddcci.conf"
29659 (kernel-loadable-modules (list ddcci-driver-linux)))
29664 @cindex compressed swap
29665 @cindex Compressed RAM-based block devices
29666 @subsubheading Zram Device Service
29668 The Zram device service provides a compressed swap device in system
29669 memory. The Linux Kernel documentation has more information about
29670 @uref{https://www.kernel.org/doc/html/latest/admin-guide/blockdev/zram.html,zram}
29673 @deffn {Scheme Variable} zram-device-service-type
29674 This service creates the zram block device, formats it as swap and
29675 enables it as a swap device. The service's value is a
29676 @code{zram-device-configuration} record.
29678 @deftp {Data Type} zram-device-configuration
29679 This is the data type representing the configuration for the zram-device
29683 @item @code{size} (default @code{"1G"})
29684 This is the amount of space you wish to provide for the zram device. It
29685 accepts a string and can be a number of bytes or use a suffix, eg.:
29686 @code{"512M"} or @code{1024000}.
29687 @item @code{compression-algorithm} (default @code{'lzo})
29688 This is the compression algorithm you wish to use. It is difficult to
29689 list all the possible compression options, but common ones supported by
29690 Guix's Linux Libre Kernel include @code{'lzo}, @code{'lz4} and @code{'zstd}.
29691 @item @code{memory-limit} (default @code{0})
29692 This is the maximum amount of memory which the zram device can use.
29693 Setting it to '0' disables the limit. While it is generally expected
29694 that compression will be 2:1, it is possible that uncompressable data
29695 can be written to swap and this is a method to limit how much memory can
29696 be used. It accepts a string and can be a number of bytes or use a
29697 suffix, eg.: @code{"2G"}.
29698 @item @code{priority} (default @code{-1})
29699 This is the priority of the swap device created from the zram device.
29700 @code{swapon} accepts values between -1 and 32767, with higher values
29701 indicating higher priority. Higher priority swap will generally be used
29708 @node Hurd Services
29709 @subsection Hurd Services
29711 @defvr {Scheme Variable} hurd-console-service-type
29712 This service starts the fancy @code{VGA} console client on the Hurd.
29714 The service's value is a @code{hurd-console-configuration} record.
29717 @deftp {Data Type} hurd-console-configuration
29718 This is the data type representing the configuration for the
29719 hurd-console-service.
29722 @item @code{hurd} (default: @var{hurd})
29723 The Hurd package to use.
29727 @defvr {Scheme Variable} hurd-getty-service-type
29728 This service starts a tty using the Hurd @code{getty} program.
29730 The service's value is a @code{hurd-getty-configuration} record.
29733 @deftp {Data Type} hurd-getty-configuration
29734 This is the data type representing the configuration for the
29735 hurd-getty-service.
29738 @item @code{hurd} (default: @var{hurd})
29739 The Hurd package to use.
29742 The name of the console this Getty runs on---e.g., @code{"tty1"}.
29744 @item @code{baud-rate} (default: @code{38400})
29745 An integer specifying the baud rate of the tty.
29750 @node Miscellaneous Services
29751 @subsection Miscellaneous Services
29753 @cindex fingerprint
29754 @subsubheading Fingerprint Service
29756 The @code{(gnu services authentication)} module provides a DBus service to
29757 read and identify fingerprints via a fingerprint sensor.
29759 @defvr {Scheme Variable} fprintd-service-type
29760 The service type for @command{fprintd}, which provides the fingerprint
29761 reading capability.
29764 (service fprintd-service-type)
29769 @subsubheading System Control Service
29771 The @code{(gnu services sysctl)} provides a service to configure kernel
29772 parameters at boot.
29774 @defvr {Scheme Variable} sysctl-service-type
29775 The service type for @command{sysctl}, which modifies kernel parameters
29776 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
29780 (service sysctl-service-type
29781 (sysctl-configuration
29782 (settings '(("net.ipv4.ip_forward" . "1")))))
29786 @deftp {Data Type} sysctl-configuration
29787 The data type representing the configuration of @command{sysctl}.
29790 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
29791 The @command{sysctl} executable to use.
29793 @item @code{settings} (default: @code{'()})
29794 An association list specifies kernel parameters and their values.
29799 @subsubheading PC/SC Smart Card Daemon Service
29801 The @code{(gnu services security-token)} module provides the following service
29802 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
29803 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
29804 manager that coordinates communications with smart card readers, smart cards
29805 and cryptographic tokens that are connected to the system.
29807 @defvr {Scheme Variable} pcscd-service-type
29808 Service type for the @command{pcscd} service. Its value must be a
29809 @code{pcscd-configuration} object. To run pcscd in the default
29810 configuration, instantiate it as:
29813 (service pcscd-service-type)
29817 @deftp {Data Type} pcscd-configuration
29818 The data type representing the configuration of @command{pcscd}.
29821 @item @code{pcsc-lite} (default: @code{pcsc-lite})
29822 The pcsc-lite package that provides pcscd.
29823 @item @code{usb-drivers} (default: @code{(list ccid)})
29824 List of packages that provide USB drivers to pcscd. Drivers are expected to be
29825 under @file{pcsc/drivers} in the store directory of the package.
29830 @subsubheading Lirc Service
29832 The @code{(gnu services lirc)} module provides the following service.
29834 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
29835 [#:device #f] [#:driver #f] [#:config-file #f] @
29836 [#:extra-options '()]
29837 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
29838 decodes infrared signals from remote controls.
29840 Optionally, @var{device}, @var{driver} and @var{config-file}
29841 (configuration file name) may be specified. See @command{lircd} manual
29844 Finally, @var{extra-options} is a list of additional command-line options
29845 passed to @command{lircd}.
29849 @subsubheading Spice Service
29851 The @code{(gnu services spice)} module provides the following service.
29853 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
29854 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
29855 that enables sharing the clipboard with a vm and setting the guest display
29856 resolution when the graphical console window resizes.
29859 @cindex inputattach
29860 @subsubheading inputattach Service
29862 @cindex tablet input, for Xorg
29863 @cindex touchscreen input, for Xorg
29864 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
29865 use input devices such as Wacom tablets, touchscreens, or joysticks with the
29866 Xorg display server.
29868 @deffn {Scheme Variable} inputattach-service-type
29869 Type of a service that runs @command{inputattach} on a device and
29870 dispatches events from it.
29873 @deftp {Data Type} inputattach-configuration
29875 @item @code{device-type} (default: @code{"wacom"})
29876 The type of device to connect to. Run @command{inputattach --help}, from the
29877 @code{inputattach} package, to see the list of supported device types.
29879 @item @code{device} (default: @code{"/dev/ttyS0"})
29880 The device file to connect to the device.
29882 @item @code{baud-rate} (default: @code{#f})
29883 Baud rate to use for the serial connection.
29884 Should be a number or @code{#f}.
29886 @item @code{log-file} (default: @code{#f})
29887 If true, this must be the name of a file to log messages to.
29891 @subsubheading Dictionary Service
29893 The @code{(gnu services dict)} module provides the following service:
29895 @defvr {Scheme Variable} dicod-service-type
29896 This is the type of the service that runs the @command{dicod} daemon, an
29897 implementation of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
29900 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
29901 Return a service that runs the @command{dicod} daemon, an implementation
29902 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
29904 The optional @var{config} argument specifies the configuration for
29905 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
29906 default it serves the GNU Collaborative International Dictionary of English.
29908 You can add @command{open localhost} to your @file{~/.dico} file to make
29909 @code{localhost} the default server for @command{dico} client
29910 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
29913 @deftp {Data Type} dicod-configuration
29914 Data type representing the configuration of dicod.
29917 @item @code{dico} (default: @var{dico})
29918 Package object of the GNU Dico dictionary server.
29920 @item @code{interfaces} (default: @var{'("localhost")})
29921 This is the list of IP addresses and ports and possibly socket file
29922 names to listen to (@pxref{Server Settings, @code{listen} directive,,
29923 dico, GNU Dico Manual}).
29925 @item @code{handlers} (default: @var{'()})
29926 List of @code{<dicod-handler>} objects denoting handlers (module instances).
29928 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
29929 List of @code{<dicod-database>} objects denoting dictionaries to be served.
29933 @deftp {Data Type} dicod-handler
29934 Data type representing a dictionary handler (module instance).
29938 Name of the handler (module instance).
29940 @item @code{module} (default: @var{#f})
29941 Name of the dicod module of the handler (instance). If it is @code{#f},
29942 the module has the same name as the handler.
29943 (@pxref{Modules,,, dico, GNU Dico Manual}).
29945 @item @code{options}
29946 List of strings or gexps representing the arguments for the module handler
29950 @deftp {Data Type} dicod-database
29951 Data type representing a dictionary database.
29955 Name of the database, will be used in DICT commands.
29957 @item @code{handler}
29958 Name of the dicod handler (module instance) used by this database
29959 (@pxref{Handlers,,, dico, GNU Dico Manual}).
29961 @item @code{complex?} (default: @var{#f})
29962 Whether the database configuration complex. The complex configuration
29963 will need a corresponding @code{<dicod-handler>} object, otherwise not.
29965 @item @code{options}
29966 List of strings or gexps representing the arguments for the database
29967 (@pxref{Databases,,, dico, GNU Dico Manual}).
29971 @defvr {Scheme Variable} %dicod-database:gcide
29972 A @code{<dicod-database>} object serving the GNU Collaborative International
29973 Dictionary of English using the @code{gcide} package.
29976 The following is an example @code{dicod-service} configuration.
29979 (dicod-service #:config
29980 (dicod-configuration
29981 (handlers (list (dicod-handler
29985 (list #~(string-append "dbdir=" #$wordnet))))))
29986 (databases (list (dicod-database
29989 (handler "wordnet")
29990 (options '("database=wn")))
29991 %dicod-database:gcide))))
29995 @subsubheading Docker Service
29997 The @code{(gnu services docker)} module provides the following services.
29999 @defvr {Scheme Variable} docker-service-type
30001 This is the type of the service that runs @url{https://www.docker.com,Docker},
30002 a daemon that can execute application bundles (sometimes referred to as
30003 ``containers'') in isolated environments.
30007 @deftp {Data Type} docker-configuration
30008 This is the data type representing the configuration of Docker and Containerd.
30012 @item @code{package} (default: @code{docker})
30013 The Docker daemon package to use.
30015 @item @code{package} (default: @code{docker-cli})
30016 The Docker client package to use.
30018 @item @code{containerd} (default: @var{containerd})
30019 The Containerd package to use.
30021 @item @code{proxy} (default @var{docker-libnetwork-cmd-proxy})
30022 The Docker user-land networking proxy package to use.
30024 @item @code{enable-proxy?} (default @code{#t})
30025 Enable or disable the use of the Docker user-land networking proxy.
30027 @item @code{debug?} (default @code{#f})
30028 Enable or disable debug output.
30030 @item @code{enable-iptables?} (default @code{#t})
30031 Enable or disable the addition of iptables rules.
30036 @cindex Singularity, container service
30037 @defvr {Scheme Variable} singularity-service-type
30038 This is the type of the service that allows you to run
30039 @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
30040 create and run application bundles (aka. ``containers''). The value for this
30041 service is the Singularity package to use.
30043 The service does not install a daemon; instead, it installs helper programs as
30044 setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
30045 @command{singularity run} and similar commands.
30049 @subsubheading Auditd Service
30051 The @code{(gnu services auditd)} module provides the following service.
30053 @defvr {Scheme Variable} auditd-service-type
30055 This is the type of the service that runs
30056 @url{https://people.redhat.com/sgrubb/audit/,auditd},
30057 a daemon that tracks security-relevant information on your system.
30059 Examples of things that can be tracked:
30069 Failed login attempts
30076 @command{auditctl} from the @code{audit} package can be used in order
30077 to add or remove events to be tracked (until the next reboot).
30078 In order to permanently track events, put the command line arguments
30079 of auditctl into a file called @code{audit.rules} in the configuration
30080 directory (see below).
30081 @command{aureport} from the @code{audit} package can be used in order
30082 to view a report of all recorded events.
30083 The audit daemon by default logs into the file
30084 @file{/var/log/audit.log}.
30088 @deftp {Data Type} auditd-configuration
30089 This is the data type representing the configuration of auditd.
30093 @item @code{audit} (default: @code{audit})
30094 The audit package to use.
30096 @item @code{configuration-directory} (default: @code{%default-auditd-configuration-directory})
30097 The directory containing the configuration file for the audit package, which
30098 must be named @code{auditd.conf}, and optionally some audit rules to
30099 instantiate on startup.
30105 @subsubheading R-Shiny service
30107 The @code{(gnu services science)} module provides the following service.
30109 @defvr {Scheme Variable} rshiny-service-type
30111 This is a type of service which is used to run a webapp created with
30112 @code{r-shiny}. This service sets the @env{R_LIBS_USER} environment
30113 variable and runs the provided script to call @code{runApp}.
30115 @deftp {Data Type} rshiny-configuration
30116 This is the data type representing the configuration of rshiny.
30120 @item @code{package} (default: @code{r-shiny})
30121 The package to use.
30123 @item @code{binary} (defaunlt @code{"rshiny"})
30124 The name of the binary or shell script located at @code{package/bin/} to
30125 run when the service is run.
30127 The common way to create this file is as follows:
30131 (let* ((out (assoc-ref %outputs "out"))
30132 (targetdir (string-append out "/share/" ,name))
30133 (app (string-append out "/bin/" ,name))
30134 (Rbin (string-append (assoc-ref %build-inputs "r-min")
30137 (mkdir-p (string-append out "/bin"))
30138 (call-with-output-file app
30144 runApp(launch.browser=0, port=4202)~%\n"
30153 @subsubheading Nix service
30155 The @code{(gnu services nix)} module provides the following service.
30157 @defvr {Scheme Variable} nix-service-type
30159 This is the type of the service that runs build daemon of the
30160 @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
30164 (use-modules (gnu))
30165 (use-service-modules nix)
30166 (use-package-modules package-management)
30170 (packages (append (list nix)
30173 (services (append (list (service nix-service-type))
30177 After @command{guix system reconfigure} configure Nix for your user:
30180 @item Add a Nix channel and update it. See
30181 @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
30183 @item Create a symlink to your profile and activate Nix profile:
30187 $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
30188 $ source /run/current-system/profile/etc/profile.d/nix.sh
30193 @deftp {Data Type} nix-configuration
30194 This data type represents the configuration of the Nix daemon.
30197 @item @code{nix} (default: @code{nix})
30198 The Nix package to use.
30200 @item @code{sandbox} (default: @code{#t})
30201 Specifies whether builds are sandboxed by default.
30203 @item @code{build-sandbox-items} (default: @code{'()})
30204 This is a list of strings or objects appended to the
30205 @code{build-sandbox-items} field of the configuration file.
30207 @item @code{extra-config} (default: @code{'()})
30208 This is a list of strings or objects appended to the configuration file.
30209 It is used to pass extra text to be added verbatim to the configuration
30212 @item @code{extra-options} (default: @code{'()})
30213 Extra command line options for @code{nix-service-type}.
30217 @node Setuid Programs
30218 @section Setuid Programs
30220 @cindex setuid programs
30221 Some programs need to run with ``root'' privileges, even when they are
30222 launched by unprivileged users. A notorious example is the
30223 @command{passwd} program, which users can run to change their
30224 password, and which needs to access the @file{/etc/passwd} and
30225 @file{/etc/shadow} files---something normally restricted to root, for
30226 obvious security reasons. To address that, these executables are
30227 @dfn{setuid-root}, meaning that they always run with root privileges
30228 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
30229 for more info about the setuid mechanism).
30231 The store itself @emph{cannot} contain setuid programs: that would be a
30232 security issue since any user on the system can write derivations that
30233 populate the store (@pxref{The Store}). Thus, a different mechanism is
30234 used: instead of changing the setuid bit directly on files that are in
30235 the store, we let the system administrator @emph{declare} which programs
30236 should be setuid root.
30238 The @code{setuid-programs} field of an @code{operating-system}
30239 declaration contains a list of G-expressions denoting the names of
30240 programs to be setuid-root (@pxref{Using the Configuration System}).
30241 For instance, the @command{passwd} program, which is part of the Shadow
30242 package, can be designated by this G-expression (@pxref{G-Expressions}):
30245 #~(string-append #$shadow "/bin/passwd")
30248 A default set of setuid programs is defined by the
30249 @code{%setuid-programs} variable of the @code{(gnu system)} module.
30251 @defvr {Scheme Variable} %setuid-programs
30252 A list of G-expressions denoting common programs that are setuid-root.
30254 The list includes commands such as @command{passwd}, @command{ping},
30255 @command{su}, and @command{sudo}.
30258 Under the hood, the actual setuid programs are created in the
30259 @file{/run/setuid-programs} directory at system activation time. The
30260 files in this directory refer to the ``real'' binaries, which are in the
30263 @node X.509 Certificates
30264 @section X.509 Certificates
30266 @cindex HTTPS, certificates
30267 @cindex X.509 certificates
30269 Web servers available over HTTPS (that is, HTTP over the transport-layer
30270 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
30271 that the client can then use to @emph{authenticate} the server. To do
30272 that, clients verify that the server's certificate is signed by a
30273 so-called @dfn{certificate authority} (CA). But to verify the CA's
30274 signature, clients must have first acquired the CA's certificate.
30276 Web browsers such as GNU@tie{}IceCat include their own set of CA
30277 certificates, such that they are able to verify CA signatures
30280 However, most other programs that can talk HTTPS---@command{wget},
30281 @command{git}, @command{w3m}, etc.---need to be told where CA
30282 certificates can be found.
30284 @cindex @code{nss-certs}
30285 In Guix, this is done by adding a package that provides certificates
30286 to the @code{packages} field of the @code{operating-system} declaration
30287 (@pxref{operating-system Reference}). Guix includes one such package,
30288 @code{nss-certs}, which is a set of CA certificates provided as part of
30289 Mozilla's Network Security Services.
30291 Note that it is @emph{not} part of @code{%base-packages}, so you need to
30292 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
30293 most applications and libraries look for certificates by default, points
30294 to the certificates installed globally.
30296 Unprivileged users, including users of Guix on a foreign distro,
30297 can also install their own certificate package in
30298 their profile. A number of environment variables need to be defined so
30299 that applications and libraries know where to find them. Namely, the
30300 OpenSSL library honors the @env{SSL_CERT_DIR} and @env{SSL_CERT_FILE}
30301 variables. Some applications add their own environment variables; for
30302 instance, the Git version control system honors the certificate bundle
30303 pointed to by the @env{GIT_SSL_CAINFO} environment variable. Thus, you
30304 would typically run something like:
30307 guix install nss-certs
30308 export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
30309 export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
30310 export GIT_SSL_CAINFO="$SSL_CERT_FILE"
30313 As another example, R requires the @env{CURL_CA_BUNDLE} environment
30314 variable to point to a certificate bundle, so you would have to run
30315 something like this:
30318 guix install nss-certs
30319 export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
30322 For other applications you may want to look up the required environment
30323 variable in the relevant documentation.
30326 @node Name Service Switch
30327 @section Name Service Switch
30329 @cindex name service switch
30331 The @code{(gnu system nss)} module provides bindings to the
30332 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
30333 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
30334 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
30335 extended with new ``name'' lookup methods for system databases, which
30336 includes host names, service names, user accounts, and more (@pxref{Name
30337 Service Switch, System Databases and Name Service Switch,, libc, The GNU
30338 C Library Reference Manual}).
30340 The NSS configuration specifies, for each system database, which lookup
30341 method is to be used, and how the various methods are chained
30342 together---for instance, under which circumstances NSS should try the
30343 next method in the list. The NSS configuration is given in the
30344 @code{name-service-switch} field of @code{operating-system} declarations
30345 (@pxref{operating-system Reference, @code{name-service-switch}}).
30348 @cindex .local, host name lookup
30349 As an example, the declaration below configures the NSS to use the
30350 @uref{https://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
30351 back-end}, which supports host name lookups over multicast DNS (mDNS)
30352 for host names ending in @code{.local}:
30355 (name-service-switch
30356 (hosts (list %files ;first, check /etc/hosts
30358 ;; If the above did not succeed, try
30359 ;; with 'mdns_minimal'.
30361 (name "mdns_minimal")
30363 ;; 'mdns_minimal' is authoritative for
30364 ;; '.local'. When it returns "not found",
30365 ;; no need to try the next methods.
30366 (reaction (lookup-specification
30367 (not-found => return))))
30369 ;; Then fall back to DNS.
30373 ;; Finally, try with the "full" 'mdns'.
30378 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
30379 contains this configuration, so you will not have to type it if all you
30380 want is to have @code{.local} host lookup working.
30382 Note that, in this case, in addition to setting the
30383 @code{name-service-switch} of the @code{operating-system} declaration,
30384 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
30385 @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
30386 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
30387 to the name service cache daemon (@pxref{Base Services,
30388 @code{nscd-service}}).
30390 For convenience, the following variables provide typical NSS
30393 @defvr {Scheme Variable} %default-nss
30394 This is the default name service switch configuration, a
30395 @code{name-service-switch} object.
30398 @defvr {Scheme Variable} %mdns-host-lookup-nss
30399 This is the name service switch configuration with support for host name
30400 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
30403 The reference for name service switch configuration is given below. It
30404 is a direct mapping of the configuration file format of the C library , so
30405 please refer to the C library manual for more information (@pxref{NSS
30406 Configuration File,,, libc, The GNU C Library Reference Manual}).
30407 Compared to the configuration file format of libc NSS, it has the advantage
30408 not only of adding this warm parenthetic feel that we like, but also
30409 static checks: you will know about syntax errors and typos as soon as you
30410 run @command{guix system}.
30412 @deftp {Data Type} name-service-switch
30414 This is the data type representation the configuration of libc's name
30415 service switch (NSS). Each field below represents one of the supported
30432 The system databases handled by the NSS. Each of these fields must be a
30433 list of @code{<name-service>} objects (see below).
30437 @deftp {Data Type} name-service
30439 This is the data type representing an actual name service and the
30440 associated lookup action.
30444 A string denoting the name service (@pxref{Services in the NSS
30445 configuration,,, libc, The GNU C Library Reference Manual}).
30447 Note that name services listed here must be visible to nscd. This is
30448 achieved by passing the @code{#:name-services} argument to
30449 @code{nscd-service} the list of packages providing the needed name
30450 services (@pxref{Base Services, @code{nscd-service}}).
30453 An action specified using the @code{lookup-specification} macro
30454 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
30455 Reference Manual}). For example:
30458 (lookup-specification (unavailable => continue)
30459 (success => return))
30464 @node Initial RAM Disk
30465 @section Initial RAM Disk
30468 @cindex initial RAM disk
30469 For bootstrapping purposes, the Linux-Libre kernel is passed an
30470 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
30471 root file system as well as an initialization script. The latter is
30472 responsible for mounting the real root file system, and for loading any
30473 kernel modules that may be needed to achieve that.
30475 The @code{initrd-modules} field of an @code{operating-system}
30476 declaration allows you to specify Linux-libre kernel modules that must
30477 be available in the initrd. In particular, this is where you would list
30478 modules needed to actually drive the hard disk where your root partition
30479 is---although the default value of @code{initrd-modules} should cover
30480 most use cases. For example, assuming you need the @code{megaraid_sas}
30481 module in addition to the default modules to be able to access your root
30482 file system, you would write:
30487 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
30490 @defvr {Scheme Variable} %base-initrd-modules
30491 This is the list of kernel modules included in the initrd by default.
30494 Furthermore, if you need lower-level customization, the @code{initrd}
30495 field of an @code{operating-system} declaration allows
30496 you to specify which initrd you would like to use. The @code{(gnu
30497 system linux-initrd)} module provides three ways to build an initrd: the
30498 high-level @code{base-initrd} procedure and the low-level
30499 @code{raw-initrd} and @code{expression->initrd} procedures.
30501 The @code{base-initrd} procedure is intended to cover most common uses.
30502 For example, if you want to add a bunch of kernel modules to be loaded
30503 at boot time, you can define the @code{initrd} field of the operating
30504 system declaration like this:
30507 (initrd (lambda (file-systems . rest)
30508 ;; Create a standard initrd but set up networking
30509 ;; with the parameters QEMU expects by default.
30510 (apply base-initrd file-systems
30511 #:qemu-networking? #t
30515 The @code{base-initrd} procedure also handles common use cases that
30516 involves using the system as a QEMU guest, or as a ``live'' system with
30517 volatile root file system.
30519 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
30520 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
30521 such as trying to guess which kernel modules and packages should be included
30522 to the initrd. An example use of @code{raw-initrd} is when a user has
30523 a custom Linux kernel configuration and default kernel modules included by
30524 @code{base-initrd} are not available.
30526 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
30527 honors several options passed on the Linux kernel command line
30528 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
30529 @code{-append} option of QEMU), notably:
30532 @item --load=@var{boot}
30533 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
30534 program, once it has mounted the root file system.
30536 Guix uses this option to yield control to a boot program that runs the
30537 service activation programs and then spawns the GNU@tie{}Shepherd, the
30538 initialization system.
30540 @item --root=@var{root}
30541 Mount @var{root} as the root file system. @var{root} can be a device
30542 name like @code{/dev/sda1}, a file system label, or a file system UUID.
30543 When unspecified, the device name from the root file system of the
30544 operating system declaration is used.
30546 @item --system=@var{system}
30547 Have @file{/run/booted-system} and @file{/run/current-system} point to
30550 @item modprobe.blacklist=@var{modules}@dots{}
30551 @cindex module, black-listing
30552 @cindex black list, of kernel modules
30553 Instruct the initial RAM disk as well as the @command{modprobe} command
30554 (from the kmod package) to refuse to load @var{modules}. @var{modules}
30555 must be a comma-separated list of module names---e.g.,
30556 @code{usbkbd,9pnet}.
30559 Start a read-eval-print loop (REPL) from the initial RAM disk before it
30560 tries to load kernel modules and to mount the root file system. Our
30561 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
30562 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
30563 Manual}, for more information on Guile's REPL.
30567 Now that you know all the features that initial RAM disks produced by
30568 @code{base-initrd} and @code{raw-initrd} provide,
30569 here is how to use it and customize it further.
30572 @cindex initial RAM disk
30573 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
30574 [#:linux-modules '()] [#:mapped-devices '()] @
30575 [#:keyboard-layout #f] @
30576 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
30577 Return a derivation that builds a raw initrd. @var{file-systems} is
30578 a list of file systems to be mounted by the initrd, possibly in addition to
30579 the root file system specified on the kernel command line via @option{--root}.
30580 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
30581 @var{mapped-devices} is a list of device mappings to realize before
30582 @var{file-systems} are mounted (@pxref{Mapped Devices}).
30583 @var{helper-packages} is a list of packages to be copied in the initrd. It may
30584 include @code{e2fsck/static} or other packages needed by the initrd to check
30585 the root file system.
30587 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
30588 the desired console keyboard layout. This is done before @var{mapped-devices}
30589 are set up and before @var{file-systems} are mounted such that, should the
30590 user need to enter a passphrase or use the REPL, this happens using the
30591 intended keyboard layout.
30593 When @var{qemu-networking?} is true, set up networking with the standard QEMU
30594 parameters. When @var{virtio?} is true, load additional modules so that the
30595 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
30597 When @var{volatile-root?} is true, the root file system is writable but any changes
30601 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
30602 [#:mapped-devices '()] [#:keyboard-layout #f] @
30603 [#:qemu-networking? #f] [#:volatile-root? #f] @
30604 [#:linux-modules '()]
30605 Return as a file-like object a generic initrd, with kernel
30606 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
30607 mounted by the initrd, possibly in addition to the root file system specified
30608 on the kernel command line via @option{--root}. @var{mapped-devices} is a list of device
30609 mappings to realize before @var{file-systems} are mounted.
30611 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
30612 the desired console keyboard layout. This is done before @var{mapped-devices}
30613 are set up and before @var{file-systems} are mounted such that, should the
30614 user need to enter a passphrase or use the REPL, this happens using the
30615 intended keyboard layout.
30617 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
30619 The initrd is automatically populated with all the kernel modules necessary
30620 for @var{file-systems} and for the given options. Additional kernel
30621 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
30622 loaded at boot time in the order in which they appear.
30625 Needless to say, the initrds we produce and use embed a
30626 statically-linked Guile, and the initialization program is a Guile
30627 program. That gives a lot of flexibility. The
30628 @code{expression->initrd} procedure builds such an initrd, given the
30629 program to run in that initrd.
30631 @deffn {Scheme Procedure} expression->initrd @var{exp} @
30632 [#:guile %guile-3.0-static-stripped] [#:name "guile-initrd"]
30633 Return as a file-like object a Linux initrd (a gzipped cpio archive)
30634 containing @var{guile} and that evaluates @var{exp}, a G-expression,
30635 upon booting. All the derivations referenced by @var{exp} are
30636 automatically copied to the initrd.
30639 @node Bootloader Configuration
30640 @section Bootloader Configuration
30643 @cindex boot loader
30645 The operating system supports multiple bootloaders. The bootloader is
30646 configured using @code{bootloader-configuration} declaration. All the
30647 fields of this structure are bootloader agnostic except for one field,
30648 @code{bootloader} that indicates the bootloader to be configured and
30651 Some of the bootloaders do not honor every field of
30652 @code{bootloader-configuration}. For instance, the extlinux
30653 bootloader does not support themes and thus ignores the @code{theme}
30656 @deftp {Data Type} bootloader-configuration
30657 The type of a bootloader configuration declaration.
30661 @item @code{bootloader}
30662 @cindex EFI, bootloader
30663 @cindex UEFI, bootloader
30664 @cindex BIOS, bootloader
30665 The bootloader to use, as a @code{bootloader} object. For now
30666 @code{grub-bootloader}, @code{grub-efi-bootloader},
30667 @code{grub-efi-netboot-bootloader}, @code{extlinux-bootloader} and
30668 @code{u-boot-bootloader} are supported.
30670 @cindex ARM, bootloaders
30671 @cindex AArch64, bootloaders
30672 Available bootloaders are described in @code{(gnu bootloader @dots{})}
30673 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
30674 of bootloaders for a wide range of ARM and AArch64 systems, using the
30675 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
30677 @vindex grub-efi-bootloader
30678 @code{grub-efi-bootloader} allows to boot on modern systems using the
30679 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
30680 use if the installation image contains a @file{/sys/firmware/efi} directory
30681 when you boot it on your system.
30683 @vindex grub-bootloader
30684 @code{grub-bootloader} allows you to boot in particular Intel-based machines
30685 in ``legacy'' BIOS mode.
30687 @vindex grub-efi-netboot-bootloader
30688 @code{grub-efi-netboot-bootloader} allows you to boot your system over network
30689 through TFTP. In combination with an NFS root file system this allows you to
30690 build a diskless Guix system.
30692 The installation of the @code{grub-efi-netboot-bootloader} generates the content
30693 of the TFTP root directory at @code{target}
30694 (@pxref{Bootloader Configuration, @code{target}}), to be served by a TFTP server.
30695 You may want to mount your TFTP server directory onto @code{target} to move the
30696 required files to the TFTP server automatically.
30698 If you plan to use an NFS root file system as well (actually if you mount the
30699 store from an NFS share), then the TFTP server needs to serve the file
30700 @file{/boot/grub/grub.cfg} and other files from the store (like GRUBs background
30701 image, the kernel (@pxref{operating-system Reference, @code{kernel}}) and the
30702 initrd (@pxref{operating-system Reference, @code{initrd}})), too. All these
30703 files from the store will be accessed by GRUB through TFTP with their normal
30704 store path, for example as
30705 @file{tftp://tftp-server/gnu/store/…-initrd/initrd.cpio.gz}.
30707 Two symlinks are created to make this possible. The first symlink is
30708 @code{target}@file{/efi/Guix/boot/grub/grub.cfg} pointing to
30709 @file{../../../boot/grub/grub.cfg},
30710 where @code{target} may be @file{/boot}. In this case the link is not leaving
30711 the served TFTP root directory, but otherwise it does. The second link is
30712 @code{target}@file{/gnu/store} and points to @file{../gnu/store}. This link
30713 is leaving the served TFTP root directory.
30715 The assumption behind all this is that you have an NFS server exporting the root
30716 file system for your Guix system, and additionally a TFTP server exporting your
30717 @code{target} directory—usually @file{/boot}—from that same root file system for
30718 your Guix system. In this constellation the symlinks will work.
30720 For other constellations you will have to program your own bootloader installer,
30721 which then takes care to make necessary files from the store accessible through
30722 TFTP, for example by copying them into the TFTP root directory at @code{target}.
30724 It is important to note that symlinks pointing outside the TFTP root directory
30725 may need to be allowed in the configuration of your TFTP server. Further the
30726 store link exposes the whole store through TFTP. Both points need to be
30727 considered carefully for security aspects.
30729 Beside the @code{grub-efi-netboot-bootloader}, the already mentioned TFTP and
30730 NFS servers, you also need a properly configured DHCP server to make the booting
30731 over netboot possible. For all this we can currently only recommend you to look
30732 for instructions about @acronym{PXE, Preboot eXecution Environment}.
30734 @item @code{target}
30735 This is a string denoting the target onto which to install the
30738 The interpretation depends on the bootloader in question. For
30739 @code{grub-bootloader}, for example, it should be a device name understood by
30740 the bootloader @command{installer} command, such as @code{/dev/sda} or
30741 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
30742 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
30743 system, usually @file{/boot/efi}. For @code{grub-efi-netboot-bootloader},
30744 @code{target} should be the mount point corresponding to the TFTP root
30745 directory of your TFTP server.
30747 @item @code{menu-entries} (default: @code{()})
30748 A possibly empty list of @code{menu-entry} objects (see below), denoting
30749 entries to appear in the bootloader menu, in addition to the current
30750 system entry and the entry pointing to previous system generations.
30752 @item @code{default-entry} (default: @code{0})
30753 The index of the default boot menu entry. Index 0 is for the entry of the
30756 @item @code{timeout} (default: @code{5})
30757 The number of seconds to wait for keyboard input before booting. Set to
30758 0 to boot immediately, and to -1 to wait indefinitely.
30760 @cindex keyboard layout, for the bootloader
30761 @item @code{keyboard-layout} (default: @code{#f})
30762 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
30763 layout, usually US@tie{}English (``qwerty'').
30765 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
30769 This option is currently ignored by bootloaders other than @code{grub} and
30773 @item @code{theme} (default: @var{#f})
30774 The bootloader theme object describing the theme to use. If no theme
30775 is provided, some bootloaders might use a default theme, that's true
30778 @item @code{terminal-outputs} (default: @code{'(gfxterm)})
30779 The output terminals used for the bootloader boot menu, as a list of
30780 symbols. GRUB accepts the values: @code{console}, @code{serial},
30781 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
30782 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
30783 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
30784 configuration,,, grub,GNU GRUB manual}).
30786 @item @code{terminal-inputs} (default: @code{'()})
30787 The input terminals used for the bootloader boot menu, as a list of
30788 symbols. For GRUB, the default is the native platform terminal as
30789 determined at run-time. GRUB accepts the values: @code{console},
30790 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
30791 @code{usb_keyboard}. This field corresponds to the GRUB variable
30792 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
30795 @item @code{serial-unit} (default: @code{#f})
30796 The serial unit used by the bootloader, as an integer from 0 to 3.
30797 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
30798 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
30800 @item @code{serial-speed} (default: @code{#f})
30801 The speed of the serial interface, as an integer. For GRUB, the
30802 default value is chosen at run-time; currently GRUB chooses
30803 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
30810 Should you want to list additional boot menu entries @i{via} the
30811 @code{menu-entries} field above, you will need to create them with the
30812 @code{menu-entry} form. For example, imagine you want to be able to
30813 boot another distro (hard to imagine!), you can define a menu entry
30818 (label "The Other Distro")
30819 (linux "/boot/old/vmlinux-2.6.32")
30820 (linux-arguments '("root=/dev/sda2"))
30821 (initrd "/boot/old/initrd"))
30826 @deftp {Data Type} menu-entry
30827 The type of an entry in the bootloader menu.
30832 The label to show in the menu---e.g., @code{"GNU"}.
30834 @item @code{linux} (default: @code{#f})
30835 The Linux kernel image to boot, for example:
30838 (file-append linux-libre "/bzImage")
30841 For GRUB, it is also possible to specify a device explicitly in the
30842 file path using GRUB's device naming convention (@pxref{Naming
30843 convention,,, grub, GNU GRUB manual}), for example:
30846 "(hd0,msdos1)/boot/vmlinuz"
30849 If the device is specified explicitly as above, then the @code{device}
30850 field is ignored entirely.
30852 @item @code{linux-arguments} (default: @code{()})
30853 The list of extra Linux kernel command-line arguments---e.g.,
30854 @code{("console=ttyS0")}.
30856 @item @code{initrd} (default: @code{#f})
30857 A G-Expression or string denoting the file name of the initial RAM disk
30858 to use (@pxref{G-Expressions}).
30860 @item @code{device} (default: @code{#f})
30861 The device where the kernel and initrd are to be found---i.e., for GRUB,
30862 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
30864 This may be a file system label (a string), a file system UUID (a
30865 bytevector, @pxref{File Systems}), or @code{#f}, in which case
30866 the bootloader will search the device containing the file specified by
30867 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
30868 must @emph{not} be an OS device name such as @file{/dev/sda1}.
30870 @item @code{multiboot-kernel} (default: @code{#f})
30871 The kernel to boot in Multiboot-mode (@pxref{multiboot,,, grub, GNU GRUB
30872 manual}). When this field is set, a Multiboot menu-entry is generated.
30876 (file-append mach "/boot/gnumach")
30879 @item @code{multiboot-arguments} (default: @code{()})
30880 The list of extra command-line arguments for the multiboot-kernel.
30882 @item @code{multiboot-modules} (default: @code{()})
30883 The list of commands for loading Multiboot modules. For example:
30886 (list (list (file-append hurd "/hurd/ext2fs.static") "ext2fs"
30888 (list (file-append libc "/lib/ld.so.1") "exec"
30898 @c FIXME: Write documentation once it's stable.
30899 For now only GRUB has theme support. GRUB themes are created using
30900 the @code{grub-theme} form, which is not fully documented yet.
30902 @deftp {Data Type} grub-theme
30903 Data type representing the configuration of the GRUB theme.
30906 @item @code{gfxmode} (default: @code{'("auto")})
30907 The GRUB @code{gfxmode} to set (a list of screen resolution strings,
30908 @pxref{gfxmode,,, grub, GNU GRUB manual}).
30912 @deffn {Scheme Procedure} grub-theme
30913 Return the default GRUB theme used by the operating system if no
30914 @code{theme} field is specified in @code{bootloader-configuration}
30917 It comes with a fancy background image displaying the GNU and Guix
30921 For example, to override the default resolution, you may use something
30926 (bootloader-configuration
30929 (inherit (grub-theme))
30930 (gfxmode '("1024x786x32" "auto"))))))
30933 @node Invoking guix system
30934 @section Invoking @code{guix system}
30936 Once you have written an operating system declaration as seen in the
30937 previous section, it can be @dfn{instantiated} using the @command{guix
30938 system} command. The synopsis is:
30941 guix system @var{options}@dots{} @var{action} @var{file}
30944 @var{file} must be the name of a file containing an
30945 @code{operating-system} declaration. @var{action} specifies how the
30946 operating system is instantiated. Currently the following values are
30951 Display available service type definitions that match the given regular
30952 expressions, sorted by relevance:
30958 $ guix system search console
30959 name: console-fonts
30960 location: gnu/services/base.scm:806:2
30961 extends: shepherd-root
30962 description: Install the given fonts on the specified ttys (fonts are per
30963 + virtual console on GNU/Linux). The value of this service is a list of
30964 + tty/font pairs. The font can be the name of a font provided by the `kbd'
30965 + package or any valid argument to `setfont', as in this example:
30967 + '(("tty1" . "LatGrkCyr-8x16")
30968 + ("tty2" . (file-append
30970 + "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
30971 + ("tty3" . (file-append
30973 + "/share/consolefonts/ter-132n"))) ; for HDPI
30977 location: gnu/services/base.scm:1190:2
30978 extends: shepherd-root
30979 description: Provide console login using the `mingetty' program.
30983 location: gnu/services/base.scm:860:2
30985 description: Provide a console log-in service as specified by its
30986 + configuration value, a `login-configuration' object.
30992 As for @command{guix package --search}, the result is written in
30993 @code{recutils} format, which makes it easy to filter the output
30994 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
30997 Build the operating system described in @var{file}, activate it, and
30998 switch to it@footnote{This action (and the related actions
30999 @code{switch-generation} and @code{roll-back}) are usable only on
31000 systems already running Guix System.}.
31003 @c The paragraph below refers to the problem discussed at
31004 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
31005 It is highly recommended to run @command{guix pull} once before you run
31006 @command{guix system reconfigure} for the first time (@pxref{Invoking
31007 guix pull}). Failing to do that you would see an older version of Guix
31008 once @command{reconfigure} has completed.
31011 This effects all the configuration specified in @var{file}: user
31012 accounts, system services, global package list, setuid programs, etc.
31013 The command starts system services specified in @var{file} that are not
31014 currently running; if a service is currently running this command will
31015 arrange for it to be upgraded the next time it is stopped (e.g.@: by
31016 @code{herd stop X} or @code{herd restart X}).
31018 This command creates a new generation whose number is one greater than
31019 the current generation (as reported by @command{guix system
31020 list-generations}). If that generation already exists, it will be
31021 overwritten. This behavior mirrors that of @command{guix package}
31022 (@pxref{Invoking guix package}).
31024 It also adds a bootloader menu entry for the new OS configuration,
31025 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
31026 entries for older configurations to a submenu, allowing you to choose
31027 an older system generation at boot time should you need it.
31029 @cindex provenance tracking, of the operating system
31030 Upon completion, the new system is deployed under
31031 @file{/run/current-system}. This directory contains @dfn{provenance
31032 meta-data}: the list of channels in use (@pxref{Channels}) and
31033 @var{file} itself, when available. You can view it by running:
31036 guix system describe
31039 This information is useful should you later want to inspect how this
31040 particular generation was built. In fact, assuming @var{file} is
31041 self-contained, you can later rebuild generation @var{n} of your
31042 operating system with:
31045 guix time-machine \
31046 -C /var/guix/profiles/system-@var{n}-link/channels.scm -- \
31047 system reconfigure \
31048 /var/guix/profiles/system-@var{n}-link/configuration.scm
31051 You can think of it as some sort of built-in version control! Your
31052 system is not just a binary artifact: @emph{it carries its own source}.
31053 @xref{Service Reference, @code{provenance-service-type}}, for more
31054 information on provenance tracking.
31056 By default, @command{reconfigure} @emph{prevents you from downgrading
31057 your system}, which could (re)introduce security vulnerabilities and
31058 also cause problems with ``stateful'' services such as database
31059 management systems. You can override that behavior by passing
31060 @option{--allow-downgrades}.
31062 @item switch-generation
31063 @cindex generations
31064 Switch to an existing system generation. This action atomically
31065 switches the system profile to the specified system generation. It
31066 also rearranges the system's existing bootloader menu entries. It
31067 makes the menu entry for the specified system generation the default,
31068 and it moves the entries for the other generations to a submenu, if
31069 supported by the bootloader being used. The next time the system
31070 boots, it will use the specified system generation.
31072 The bootloader itself is not being reinstalled when using this
31073 command. Thus, the installed bootloader is used with an updated
31074 configuration file.
31076 The target generation can be specified explicitly by its generation
31077 number. For example, the following invocation would switch to system
31081 guix system switch-generation 7
31084 The target generation can also be specified relative to the current
31085 generation with the form @code{+N} or @code{-N}, where @code{+3} means
31086 ``3 generations ahead of the current generation,'' and @code{-1} means
31087 ``1 generation prior to the current generation.'' When specifying a
31088 negative value such as @code{-1}, you must precede it with @code{--} to
31089 prevent it from being parsed as an option. For example:
31092 guix system switch-generation -- -1
31095 Currently, the effect of invoking this action is @emph{only} to switch
31096 the system profile to an existing generation and rearrange the
31097 bootloader menu entries. To actually start using the target system
31098 generation, you must reboot after running this action. In the future,
31099 it will be updated to do the same things as @command{reconfigure},
31100 like activating and deactivating services.
31102 This action will fail if the specified generation does not exist.
31105 @cindex rolling back
31106 Switch to the preceding system generation. The next time the system
31107 boots, it will use the preceding system generation. This is the inverse
31108 of @command{reconfigure}, and it is exactly the same as invoking
31109 @command{switch-generation} with an argument of @code{-1}.
31111 Currently, as with @command{switch-generation}, you must reboot after
31112 running this action to actually start using the preceding system
31115 @item delete-generations
31116 @cindex deleting system generations
31117 @cindex saving space
31118 Delete system generations, making them candidates for garbage collection
31119 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
31122 This works in the same way as @samp{guix package --delete-generations}
31123 (@pxref{Invoking guix package, @option{--delete-generations}}). With no
31124 arguments, all system generations but the current one are deleted:
31127 guix system delete-generations
31130 You can also select the generations you want to delete. The example below
31131 deletes all the system generations that are more than two month old:
31134 guix system delete-generations 2m
31137 Running this command automatically reinstalls the bootloader with an updated
31138 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
31139 longer lists the generations that have been deleted.
31142 Build the derivation of the operating system, which includes all the
31143 configuration files and programs needed to boot and run the system.
31144 This action does not actually install anything.
31147 Populate the given directory with all the files necessary to run the
31148 operating system specified in @var{file}. This is useful for first-time
31149 installations of Guix System. For instance:
31152 guix system init my-os-config.scm /mnt
31155 copies to @file{/mnt} all the store items required by the configuration
31156 specified in @file{my-os-config.scm}. This includes configuration
31157 files, packages, and so on. It also creates other essential files
31158 needed for the system to operate correctly---e.g., the @file{/etc},
31159 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
31161 This command also installs bootloader on the target specified in
31162 @file{my-os-config}, unless the @option{--no-bootloader} option was
31166 @cindex virtual machine
31168 @anchor{guix system vm}
31169 Build a virtual machine that contains the operating system declared in
31170 @var{file}, and return a script to run that virtual machine (VM).
31173 The @code{vm} action and others below
31174 can use KVM support in the Linux-libre kernel. Specifically, if the
31175 machine has hardware virtualization support, the corresponding
31176 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
31177 must exist and be readable and writable by the user and by the
31178 build users of the daemon (@pxref{Build Environment Setup}).
31181 Arguments given to the script are passed to QEMU as in the example
31182 below, which enables networking and requests 1@tie{}GiB of RAM for the
31186 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -smp 2 -net user,model=virtio-net-pci
31189 The VM shares its store with the host system.
31191 Additional file systems can be shared between the host and the VM using
31192 the @option{--share} and @option{--expose} command-line options: the former
31193 specifies a directory to be shared with write access, while the latter
31194 provides read-only access to the shared directory.
31196 The example below creates a VM in which the user's home directory is
31197 accessible read-only, and where the @file{/exchange} directory is a
31198 read-write mapping of @file{$HOME/tmp} on the host:
31201 guix system vm my-config.scm \
31202 --expose=$HOME --share=$HOME/tmp=/exchange
31205 On GNU/Linux, the default is to boot directly to the kernel; this has
31206 the advantage of requiring only a very tiny root disk image since the
31207 store of the host can then be mounted.
31209 The @option{--full-boot} option forces a complete boot sequence, starting
31210 with the bootloader. This requires more disk space since a root image
31211 containing at least the kernel, initrd, and bootloader data files must
31212 be created. The @option{--image-size} option can be used to specify the
31215 @cindex System images, creation in various formats
31216 @cindex Creating system images in various formats
31219 @itemx docker-image
31220 Return a virtual machine, disk image, or Docker image of the operating
31221 system declared in @var{file} that stands alone. By default,
31222 @command{guix system} estimates the size of the image needed to store
31223 the system, but you can use the @option{--image-size} option to specify
31224 a value. Docker images are built to contain exactly what they need, so
31225 the @option{--image-size} option is ignored in the case of
31226 @code{docker-image}.
31228 @cindex disk-image, creating disk images
31229 The @code{disk-image} command can produce various image types. The
31230 image type can be selected using the @option{--image-type} option. It
31231 defaults to @code{raw}. When its value is @code{iso9660}, the
31232 @option{--label} option can be used to specify a volume ID with
31233 @code{disk-image}. By default, the root file system of a disk image is
31234 mounted non-volatile; the @option{--volatile} option can be provided to
31235 make it volatile instead. When using @code{disk-image}, the bootloader
31236 installed on the generated image is taken from the provided
31237 @code{operating-system} definition. The following example demonstrates
31238 how to generate an image that uses the @code{grub-efi-bootloader}
31239 bootloader and boot it with QEMU:
31242 image=$(guix system disk-image --image-type=qcow2 \
31243 gnu/system/examples/lightweight-desktop.tmpl)
31244 cp $image /tmp/my-image.qcow2
31245 chmod +w /tmp/my-image.qcow2
31246 qemu-system-x86_64 -enable-kvm -hda /tmp/my-image.qcow2 -m 1000 \
31247 -bios $(guix build ovmf)/share/firmware/ovmf_x64.bin
31250 When using the @code{raw} image type, a raw disk image is produced; it
31251 can be copied as is to a USB stick, for instance. Assuming
31252 @code{/dev/sdc} is the device corresponding to a USB stick, one can copy
31253 the image to it using the following command:
31256 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc status=progress
31259 The @code{--list-image-types} command lists all the available image
31262 @cindex vm-image, creating virtual machine images
31263 When using @code{vm-image}, the returned image is in qcow2 format, which
31264 the QEMU emulator can efficiently use. @xref{Running Guix in a VM}, for
31265 more information on how to run the image in a virtual machine. The
31266 @code{grub-bootloader} bootloader is always used independently of what
31267 is declared in the @code{operating-system} file passed as argument.
31268 This is to make it easier to work with QEMU, which uses the SeaBIOS BIOS
31269 by default, expecting a bootloader to be installed in the Master Boot
31272 @cindex docker-image, creating docker images
31273 When using @code{docker-image}, a Docker image is produced. Guix builds
31274 the image from scratch, not from a pre-existing Docker base image. As a
31275 result, it contains @emph{exactly} what you define in the operating
31276 system configuration file. You can then load the image and launch a
31277 Docker container using commands like the following:
31280 image_id="`docker load < guix-system-docker-image.tar.gz`"
31281 container_id="`docker create $image_id`"
31282 docker start $container_id
31285 This command starts a new Docker container from the specified image. It
31286 will boot the Guix system in the usual manner, which means it will
31287 start any services you have defined in the operating system
31288 configuration. You can get an interactive shell running in the container
31289 using @command{docker exec}:
31292 docker exec -ti $container_id /run/current-system/profile/bin/bash --login
31295 Depending on what you run in the Docker container, it
31296 may be necessary to give the container additional permissions. For
31297 example, if you intend to build software using Guix inside of the Docker
31298 container, you may need to pass the @option{--privileged} option to
31299 @code{docker create}.
31301 Last, the @option{--network} option applies to @command{guix system
31302 docker-image}: it produces an image where network is supposedly shared
31303 with the host, and thus without services like nscd or NetworkManager.
31306 Return a script to run the operating system declared in @var{file}
31307 within a container. Containers are a set of lightweight isolation
31308 mechanisms provided by the kernel Linux-libre. Containers are
31309 substantially less resource-demanding than full virtual machines since
31310 the kernel, shared objects, and other resources can be shared with the
31311 host system; this also means they provide thinner isolation.
31313 Currently, the script must be run as root in order to support more than
31314 a single user and group. The container shares its store with the host
31317 As with the @code{vm} action (@pxref{guix system vm}), additional file
31318 systems to be shared between the host and container can be specified
31319 using the @option{--share} and @option{--expose} options:
31322 guix system container my-config.scm \
31323 --expose=$HOME --share=$HOME/tmp=/exchange
31327 This option requires Linux-libre 3.19 or newer.
31332 @var{options} can contain any of the common build options (@pxref{Common
31333 Build Options}). In addition, @var{options} can contain one of the
31337 @item --expression=@var{expr}
31338 @itemx -e @var{expr}
31339 Consider the operating-system @var{expr} evaluates to.
31340 This is an alternative to specifying a file which evaluates to an
31342 This is used to generate the Guix system installer @pxref{Building the
31343 Installation Image}).
31345 @item --system=@var{system}
31346 @itemx -s @var{system}
31347 Attempt to build for @var{system} instead of the host system type.
31348 This works as per @command{guix build} (@pxref{Invoking guix build}).
31352 Return the derivation file name of the given operating system without
31355 @cindex provenance tracking, of the operating system
31356 @item --save-provenance
31357 As discussed above, @command{guix system init} and @command{guix system
31358 reconfigure} always save provenance information @i{via} a dedicated
31359 service (@pxref{Service Reference, @code{provenance-service-type}}).
31360 However, other commands don't do that by default. If you wish to, say,
31361 create a virtual machine image that contains provenance information, you
31365 guix system vm-image --save-provenance config.scm
31368 That way, the resulting image will effectively ``embed its own source''
31369 in the form of meta-data in @file{/run/current-system}. With that
31370 information, one can rebuild the image to make sure it really contains
31371 what it pretends to contain; or they could use that to derive a variant
31374 @item --image-type=@var{type}
31375 @itemx -t @var{type}
31376 For the @code{disk-image} action, create an image with given @var{type}.
31378 When this option is omitted, @command{guix system} uses the @code{raw}
31381 @cindex ISO-9660 format
31382 @cindex CD image format
31383 @cindex DVD image format
31384 @option{--image-type=iso9660} produces an ISO-9660 image, suitable
31385 for burning on CDs and DVDs.
31387 @item --image-size=@var{size}
31388 For the @code{vm-image} and @code{disk-image} actions, create an image
31389 of the given @var{size}. @var{size} may be a number of bytes, or it may
31390 include a unit as a suffix (@pxref{Block size, size specifications,,
31391 coreutils, GNU Coreutils}).
31393 When this option is omitted, @command{guix system} computes an estimate
31394 of the image size as a function of the size of the system declared in
31399 For the @code{container} action, allow containers to access the host network,
31400 that is, do not create a network namespace.
31402 @item --root=@var{file}
31403 @itemx -r @var{file}
31404 Make @var{file} a symlink to the result, and register it as a garbage
31407 @item --skip-checks
31408 Skip pre-installation safety checks.
31410 By default, @command{guix system init} and @command{guix system
31411 reconfigure} perform safety checks: they make sure the file systems that
31412 appear in the @code{operating-system} declaration actually exist
31413 (@pxref{File Systems}), and that any Linux kernel modules that may be
31414 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
31415 RAM Disk}). Passing this option skips these tests altogether.
31417 @item --allow-downgrades
31418 Instruct @command{guix system reconfigure} to allow system downgrades.
31420 By default, @command{reconfigure} prevents you from downgrading your
31421 system. It achieves that by comparing the provenance info of your
31422 system (shown by @command{guix system describe}) with that of your
31423 @command{guix} command (shown by @command{guix describe}). If the
31424 commits for @command{guix} are not descendants of those used for your
31425 system, @command{guix system reconfigure} errors out. Passing
31426 @option{--allow-downgrades} allows you to bypass these checks.
31429 Make sure you understand its security implications before using
31430 @option{--allow-downgrades}.
31434 @cindex on-error strategy
31435 @cindex error strategy
31436 @item --on-error=@var{strategy}
31437 Apply @var{strategy} when an error occurs when reading @var{file}.
31438 @var{strategy} may be one of the following:
31441 @item nothing-special
31442 Report the error concisely and exit. This is the default strategy.
31445 Likewise, but also display a backtrace.
31448 Report the error and enter Guile's debugger. From there, you can run
31449 commands such as @code{,bt} to get a backtrace, @code{,locals} to
31450 display local variable values, and more generally inspect the state of the
31451 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
31452 a list of available debugging commands.
31456 Once you have built, configured, re-configured, and re-re-configured
31457 your Guix installation, you may find it useful to list the operating
31458 system generations available on disk---and that you can choose from the
31459 bootloader boot menu:
31464 Describe the current system generation: its file name, the kernel and
31465 bootloader used, etc., as well as provenance information when available.
31467 @item list-generations
31468 List a summary of each generation of the operating system available on
31469 disk, in a human-readable way. This is similar to the
31470 @option{--list-generations} option of @command{guix package}
31471 (@pxref{Invoking guix package}).
31473 Optionally, one can specify a pattern, with the same syntax that is used
31474 in @command{guix package --list-generations}, to restrict the list of
31475 generations displayed. For instance, the following command displays
31476 generations that are up to 10 days old:
31479 $ guix system list-generations 10d
31484 The @command{guix system} command has even more to offer! The following
31485 sub-commands allow you to visualize how your system services relate to
31488 @anchor{system-extension-graph}
31491 @item extension-graph
31492 Emit in Dot/Graphviz format to standard output the @dfn{service
31493 extension graph} of the operating system defined in @var{file}
31494 (@pxref{Service Composition}, for more information on service
31500 $ guix system extension-graph @var{file} | xdot -
31503 shows the extension relations among services.
31505 @anchor{system-shepherd-graph}
31506 @item shepherd-graph
31507 Emit in Dot/Graphviz format to standard output the @dfn{dependency
31508 graph} of shepherd services of the operating system defined in
31509 @var{file}. @xref{Shepherd Services}, for more information and for an
31514 @node Invoking guix deploy
31515 @section Invoking @code{guix deploy}
31517 We've already seen @code{operating-system} declarations used to manage a
31518 machine's configuration locally. Suppose you need to configure multiple
31519 machines, though---perhaps you're managing a service on the web that's
31520 comprised of several servers. @command{guix deploy} enables you to use those
31521 same @code{operating-system} declarations to manage multiple remote hosts at
31522 once as a logical ``deployment''.
31525 The functionality described in this section is still under development
31526 and is subject to change. Get in touch with us on
31527 @email{guix-devel@@gnu.org}!
31531 guix deploy @var{file}
31534 Such an invocation will deploy the machines that the code within @var{file}
31535 evaluates to. As an example, @var{file} might contain a definition like this:
31538 ;; This is a Guix deployment of a "bare bones" setup, with
31539 ;; no X11 display server, to a machine with an SSH daemon
31540 ;; listening on localhost:2222. A configuration such as this
31541 ;; may be appropriate for virtual machine with ports
31542 ;; forwarded to the host's loopback interface.
31544 (use-service-modules networking ssh)
31545 (use-package-modules bootloaders)
31549 (host-name "gnu-deployed")
31550 (timezone "Etc/UTC")
31551 (bootloader (bootloader-configuration
31552 (bootloader grub-bootloader)
31553 (target "/dev/vda")
31554 (terminal-outputs '(console))))
31555 (file-systems (cons (file-system
31557 (device "/dev/vda1")
31559 %base-file-systems))
31561 (append (list (service dhcp-client-service-type)
31562 (service openssh-service-type
31563 (openssh-configuration
31564 (permit-root-login #t)
31565 (allow-empty-passwords? #t))))
31569 (operating-system %system)
31570 (environment managed-host-environment-type)
31571 (configuration (machine-ssh-configuration
31572 (host-name "localhost")
31573 (system "x86_64-linux")
31575 (identity "./id_rsa")
31579 The file should evaluate to a list of @var{machine} objects. This example,
31580 upon being deployed, will create a new generation on the remote system
31581 realizing the @code{operating-system} declaration @code{%system}.
31582 @code{environment} and @code{configuration} specify how the machine should be
31583 provisioned---that is, how the computing resources should be created and
31584 managed. The above example does not create any resources, as a
31585 @code{'managed-host} is a machine that is already running the Guix system and
31586 available over the network. This is a particularly simple case; a more
31587 complex deployment may involve, for example, starting virtual machines through
31588 a Virtual Private Server (VPS) provider. In such a case, a different
31589 @var{environment} type would be used.
31591 Do note that you first need to generate a key pair on the coordinator machine
31592 to allow the daemon to export signed archives of files from the store
31593 (@pxref{Invoking guix archive}), though this step is automatic on Guix
31597 # guix archive --generate-key
31601 Each target machine must authorize the key of the master machine so that it
31602 accepts store items it receives from the coordinator:
31605 # guix archive --authorize < coordinator-public-key.txt
31608 @code{user}, in this example, specifies the name of the user account to log in
31609 as to perform the deployment. Its default value is @code{root}, but root
31610 login over SSH may be forbidden in some cases. To work around this,
31611 @command{guix deploy} can log in as an unprivileged user and employ
31612 @code{sudo} to escalate privileges. This will only work if @code{sudo} is
31613 currently installed on the remote and can be invoked non-interactively as
31614 @code{user}. That is, the line in @code{sudoers} granting @code{user} the
31615 ability to use @code{sudo} must contain the @code{NOPASSWD} tag. This can
31616 be accomplished with the following operating system configuration snippet:
31620 (gnu system)) ;for %sudoers-specification
31622 (define %user "username")
31627 (plain-file "sudoers"
31628 (string-append (plain-file-content %sudoers-specification)
31629 (format #f "~a ALL = NOPASSWD: ALL~%"
31634 For more information regarding the format of the @file{sudoers} file,
31635 consult @command{man sudoers}.
31637 @deftp {Data Type} machine
31638 This is the data type representing a single machine in a heterogeneous Guix
31642 @item @code{operating-system}
31643 The object of the operating system configuration to deploy.
31645 @item @code{environment}
31646 An @code{environment-type} describing how the machine should be provisioned.
31648 @item @code{configuration} (default: @code{#f})
31649 An object describing the configuration for the machine's @code{environment}.
31650 If the @code{environment} has a default configuration, @code{#f} may be used.
31651 If @code{#f} is used for an environment with no default configuration,
31652 however, an error will be thrown.
31656 @deftp {Data Type} machine-ssh-configuration
31657 This is the data type representing the SSH client parameters for a machine
31658 with an @code{environment} of @code{managed-host-environment-type}.
31661 @item @code{host-name}
31662 @item @code{build-locally?} (default: @code{#t})
31663 If false, system derivations will be built on the machine being deployed to.
31664 @item @code{system}
31665 The system type describing the architecture of the machine being deployed
31666 to---e.g., @code{"x86_64-linux"}.
31667 @item @code{authorize?} (default: @code{#t})
31668 If true, the coordinator's signing key will be added to the remote's ACL
31670 @item @code{port} (default: @code{22})
31671 @item @code{user} (default: @code{"root"})
31672 @item @code{identity} (default: @code{#f})
31673 If specified, the path to the SSH private key to use to authenticate with the
31676 @item @code{host-key} (default: @code{#f})
31677 This should be the SSH host key of the machine, which looks like this:
31680 ssh-ed25519 AAAAC3Nz@dots{} root@@example.org
31683 When @code{host-key} is @code{#f}, the server is authenticated against
31684 the @file{~/.ssh/known_hosts} file, just like the OpenSSH @command{ssh}
31687 @item @code{allow-downgrades?} (default: @code{#f})
31688 Whether to allow potential downgrades.
31690 Like @command{guix system reconfigure}, @command{guix deploy} compares
31691 the channel commits currently deployed on the remote host (as returned
31692 by @command{guix system describe}) to those currently in use (as
31693 returned by @command{guix describe}) to determine whether commits
31694 currently in use are descendants of those deployed. When this is not
31695 the case and @code{allow-downgrades?} is false, it raises an error.
31696 This ensures you do not accidentally downgrade remote machines.
31700 @deftp {Data Type} digital-ocean-configuration
31701 This is the data type describing the Droplet that should be created for a
31702 machine with an @code{environment} of @code{digital-ocean-environment-type}.
31705 @item @code{ssh-key}
31706 The path to the SSH private key to use to authenticate with the remote
31707 host. In the future, this field may not exist.
31709 A list of string ``tags'' that uniquely identify the machine. Must be given
31710 such that no two machines in the deployment have the same set of tags.
31711 @item @code{region}
31712 A Digital Ocean region slug, such as @code{"nyc3"}.
31714 A Digital Ocean size slug, such as @code{"s-1vcpu-1gb"}
31715 @item @code{enable-ipv6?}
31716 Whether or not the droplet should be created with IPv6 networking.
31720 @node Running Guix in a VM
31721 @section Running Guix in a Virtual Machine
31723 @cindex virtual machine
31724 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
31726 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
31727 This image is a compressed image in QCOW format. You will first need to
31728 decompress with @command{xz -d}, and then you can pass it to an emulator such
31729 as QEMU (see below for details).
31731 This image boots the Xfce graphical environment and it contains some
31732 commonly used tools. You can install more software in the image by running
31733 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
31734 also reconfigure the system based on its initial configuration file available
31735 as @file{/run/current-system/configuration.scm} (@pxref{Using the
31736 Configuration System}).
31738 Instead of using this pre-built image, one can also build their own virtual
31739 machine image using @command{guix system vm-image} (@pxref{Invoking guix
31740 system}). The returned image is in qcow2 format, which the
31741 @uref{https://qemu.org/, QEMU emulator} can efficiently use.
31744 If you built your own image, you must copy it out of the store
31745 (@pxref{The Store}) and give yourself permission to write to the copy
31746 before you can use it. When invoking QEMU, you must choose a system
31747 emulator that is suitable for your hardware platform. Here is a minimal
31748 QEMU invocation that will boot the result of @command{guix system
31749 vm-image} on x86_64 hardware:
31752 $ qemu-system-x86_64 \
31753 -nic user,model=virtio-net-pci \
31754 -enable-kvm -m 1024 \
31755 -device virtio-blk,drive=myhd \
31756 -drive if=none,file=/tmp/qemu-image,id=myhd
31759 Here is what each of these options means:
31762 @item qemu-system-x86_64
31763 This specifies the hardware platform to emulate. This should match the
31766 @item -nic user,model=virtio-net-pci
31767 Enable the unprivileged user-mode network stack. The guest OS can
31768 access the host but not vice versa. This is the simplest way to get the
31769 guest OS online. @code{model} specifies which network device to emulate:
31770 @code{virtio-net-pci} is a special device made for virtualized operating
31771 systems and recommended for most uses. Assuming your hardware platform is
31772 x86_64, you can get a list of available NIC models by running
31773 @command{qemu-system-x86_64 -nic model=help}.
31776 If your system has hardware virtualization extensions, enabling the
31777 virtual machine support (KVM) of the Linux kernel will make things run
31780 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
31782 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
31783 which may be insufficient for some operations.
31785 @item -device virtio-blk,drive=myhd
31786 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
31787 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
31788 better performance than if it were emulating a complete disk drive. See the
31789 QEMU and KVM documentation for more info.
31791 @item -drive if=none,file=/tmp/qemu-image,id=myhd
31792 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing
31793 store of the ``myhd'' drive.
31796 The default @command{run-vm.sh} script that is returned by an invocation of
31797 @command{guix system vm} does not add a @command{-nic user} flag by default.
31798 To get network access from within the vm add the @code{(dhcp-client-service)}
31799 to your system definition and start the VM using
31800 @command{`guix system vm config.scm` -nic user}. An important caveat of using
31801 @command{-nic user} for networking is that @command{ping} will not work, because
31802 it uses the ICMP protocol. You'll have to use a different command to check for
31803 network connectivity, for example @command{guix download}.
31805 @subsection Connecting Through SSH
31809 To enable SSH inside a VM you need to add an SSH server like
31810 @code{openssh-service-type} to your VM (@pxref{Networking Services,
31811 @code{openssh-service-type}}). In addition you need to forward the SSH port,
31812 22 by default, to the host. You can do this with
31815 `guix system vm config.scm` -nic user,model=virtio-net-pci,hostfwd=tcp::10022-:22
31818 To connect to the VM you can run
31821 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
31824 The @command{-p} tells @command{ssh} the port you want to connect to.
31825 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
31826 every time you modify your @command{config.scm} file and the
31827 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
31828 connection to an unknown host every time you connect.
31830 @subsection Using @command{virt-viewer} with Spice
31832 As an alternative to the default @command{qemu} graphical client you can
31833 use the @command{remote-viewer} from the @command{virt-viewer} package. To
31834 connect pass the @command{-spice port=5930,disable-ticketing} flag to
31835 @command{qemu}. See previous section for further information on how to do this.
31837 Spice also allows you to do some nice stuff like share your clipboard with your
31838 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
31841 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
31842 -chardev spicevmc,name=vdagent,id=vdagent
31843 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
31844 name=com.redhat.spice.0
31847 You'll also need to add the @code{(spice-vdagent-service)} to your
31848 system definition (@pxref{Miscellaneous Services, Spice service}).
31850 @node Defining Services
31851 @section Defining Services
31853 The previous sections show the available services and how one can combine
31854 them in an @code{operating-system} declaration. But how do we define
31855 them in the first place? And what is a service anyway?
31858 * Service Composition:: The model for composing services.
31859 * Service Types and Services:: Types and services.
31860 * Service Reference:: API reference.
31861 * Shepherd Services:: A particular type of service.
31864 @node Service Composition
31865 @subsection Service Composition
31869 Here we define a @dfn{service} as, broadly, something that extends the
31870 functionality of the operating system. Often a service is a process---a
31871 @dfn{daemon}---started when the system boots: a secure shell server, a
31872 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
31873 whose execution can be triggered by another daemon---e.g., an FTP server
31874 started by @command{inetd} or a D-Bus service activated by
31875 @command{dbus-daemon}. Occasionally, a service does not map to a
31876 daemon. For instance, the ``account'' service collects user accounts
31877 and makes sure they exist when the system runs; the ``udev'' service
31878 collects device management rules and makes them available to the eudev
31879 daemon; the @file{/etc} service populates the @file{/etc} directory
31882 @cindex service extensions
31883 Guix system services are connected by @dfn{extensions}. For instance, the
31884 secure shell service @emph{extends} the Shepherd---the
31885 initialization system, running as PID@tie{}1---by giving it the command
31886 lines to start and stop the secure shell daemon (@pxref{Networking
31887 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
31888 service by passing it its @file{.service} specification, and extends the
31889 udev service by passing it device management rules (@pxref{Desktop
31890 Services, @code{upower-service}}); the Guix daemon service extends the
31891 Shepherd by passing it the command lines to start and stop the daemon,
31892 and extends the account service by passing it a list of required build
31893 user accounts (@pxref{Base Services}).
31895 All in all, services and their ``extends'' relations form a directed
31896 acyclic graph (DAG). If we represent services as boxes and extensions
31897 as arrows, a typical system might provide something like this:
31899 @image{images/service-graph,,5in,Typical service extension graph.}
31901 @cindex system service
31902 At the bottom, we see the @dfn{system service}, which produces the
31903 directory containing everything to run and boot the system, as returned
31904 by the @command{guix system build} command. @xref{Service Reference},
31905 to learn about the other service types shown here.
31906 @xref{system-extension-graph, the @command{guix system extension-graph}
31907 command}, for information on how to generate this representation for a
31908 particular operating system definition.
31910 @cindex service types
31911 Technically, developers can define @dfn{service types} to express these
31912 relations. There can be any number of services of a given type on the
31913 system---for instance, a system running two instances of the GNU secure
31914 shell server (lsh) has two instances of @code{lsh-service-type}, with
31915 different parameters.
31917 The following section describes the programming interface for service
31918 types and services.
31920 @node Service Types and Services
31921 @subsection Service Types and Services
31923 A @dfn{service type} is a node in the DAG described above. Let us start
31924 with a simple example, the service type for the Guix build daemon
31925 (@pxref{Invoking guix-daemon}):
31928 (define guix-service-type
31932 (list (service-extension shepherd-root-service-type guix-shepherd-service)
31933 (service-extension account-service-type guix-accounts)
31934 (service-extension activation-service-type guix-activation)))
31935 (default-value (guix-configuration))))
31939 It defines three things:
31943 A name, whose sole purpose is to make inspection and debugging easier.
31946 A list of @dfn{service extensions}, where each extension designates the
31947 target service type and a procedure that, given the parameters of the
31948 service, returns a list of objects to extend the service of that type.
31950 Every service type has at least one service extension. The only
31951 exception is the @dfn{boot service type}, which is the ultimate service.
31954 Optionally, a default value for instances of this type.
31957 In this example, @code{guix-service-type} extends three services:
31960 @item shepherd-root-service-type
31961 The @code{guix-shepherd-service} procedure defines how the Shepherd
31962 service is extended. Namely, it returns a @code{<shepherd-service>}
31963 object that defines how @command{guix-daemon} is started and stopped
31964 (@pxref{Shepherd Services}).
31966 @item account-service-type
31967 This extension for this service is computed by @code{guix-accounts},
31968 which returns a list of @code{user-group} and @code{user-account}
31969 objects representing the build user accounts (@pxref{Invoking
31972 @item activation-service-type
31973 Here @code{guix-activation} is a procedure that returns a gexp, which is
31974 a code snippet to run at ``activation time''---e.g., when the service is
31978 A service of this type is instantiated like this:
31981 (service guix-service-type
31982 (guix-configuration
31984 (extra-options '("--gc-keep-derivations"))))
31987 The second argument to the @code{service} form is a value representing
31988 the parameters of this specific service instance.
31989 @xref{guix-configuration-type, @code{guix-configuration}}, for
31990 information about the @code{guix-configuration} data type. When the
31991 value is omitted, the default value specified by
31992 @code{guix-service-type} is used:
31995 (service guix-service-type)
31998 @code{guix-service-type} is quite simple because it extends other
31999 services but is not extensible itself.
32001 @c @subsubsubsection Extensible Service Types
32003 The service type for an @emph{extensible} service looks like this:
32006 (define udev-service-type
32007 (service-type (name 'udev)
32009 (list (service-extension shepherd-root-service-type
32010 udev-shepherd-service)))
32012 (compose concatenate) ;concatenate the list of rules
32013 (extend (lambda (config rules)
32015 (($ <udev-configuration> udev initial-rules)
32016 (udev-configuration
32017 (udev udev) ;the udev package to use
32018 (rules (append initial-rules rules)))))))))
32021 This is the service type for the
32022 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
32023 management daemon}. Compared to the previous example, in addition to an
32024 extension of @code{shepherd-root-service-type}, we see two new fields:
32028 This is the procedure to @dfn{compose} the list of extensions to
32029 services of this type.
32031 Services can extend the udev service by passing it lists of rules; we
32032 compose those extensions simply by concatenating them.
32035 This procedure defines how the value of the service is @dfn{extended} with
32036 the composition of the extensions.
32038 Udev extensions are composed into a list of rules, but the udev service
32039 value is itself a @code{<udev-configuration>} record. So here, we
32040 extend that record by appending the list of rules it contains to the
32041 list of contributed rules.
32044 This is a string giving an overview of the service type. The string can
32045 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
32046 @command{guix system search} command searches these strings and displays
32047 them (@pxref{Invoking guix system}).
32050 There can be only one instance of an extensible service type such as
32051 @code{udev-service-type}. If there were more, the
32052 @code{service-extension} specifications would be ambiguous.
32054 Still here? The next section provides a reference of the programming
32055 interface for services.
32057 @node Service Reference
32058 @subsection Service Reference
32060 We have seen an overview of service types (@pxref{Service Types and
32061 Services}). This section provides a reference on how to manipulate
32062 services and service types. This interface is provided by the
32063 @code{(gnu services)} module.
32065 @deffn {Scheme Procedure} service @var{type} [@var{value}]
32066 Return a new service of @var{type}, a @code{<service-type>} object (see
32067 below). @var{value} can be any object; it represents the parameters of
32068 this particular service instance.
32070 When @var{value} is omitted, the default value specified by @var{type}
32071 is used; if @var{type} does not specify a default value, an error is
32074 For instance, this:
32077 (service openssh-service-type)
32081 is equivalent to this:
32084 (service openssh-service-type
32085 (openssh-configuration))
32088 In both cases the result is an instance of @code{openssh-service-type}
32089 with the default configuration.
32092 @deffn {Scheme Procedure} service? @var{obj}
32093 Return true if @var{obj} is a service.
32096 @deffn {Scheme Procedure} service-kind @var{service}
32097 Return the type of @var{service}---i.e., a @code{<service-type>} object.
32100 @deffn {Scheme Procedure} service-value @var{service}
32101 Return the value associated with @var{service}. It represents its
32105 Here is an example of how a service is created and manipulated:
32109 (service nginx-service-type
32110 (nginx-configuration
32112 (log-directory log-directory)
32113 (run-directory run-directory)
32114 (file config-file))))
32119 (eq? (service-kind s) nginx-service-type)
32123 The @code{modify-services} form provides a handy way to change the
32124 parameters of some of the services of a list such as
32125 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
32126 evaluates to a list of services. Of course, you could always use
32127 standard list combinators such as @code{map} and @code{fold} to do that
32128 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
32129 @code{modify-services} simply provides a more concise form for this
32132 @deffn {Scheme Syntax} modify-services @var{services} @
32133 (@var{type} @var{variable} => @var{body}) @dots{}
32135 Modify the services listed in @var{services} according to the given
32136 clauses. Each clause has the form:
32139 (@var{type} @var{variable} => @var{body})
32142 where @var{type} is a service type---e.g.,
32143 @code{guix-service-type}---and @var{variable} is an identifier that is
32144 bound within the @var{body} to the service parameters---e.g., a
32145 @code{guix-configuration} instance---of the original service of that
32148 The @var{body} should evaluate to the new service parameters, which will
32149 be used to configure the new service. This new service will replace the
32150 original in the resulting list. Because a service's service parameters
32151 are created using @code{define-record-type*}, you can write a succinct
32152 @var{body} that evaluates to the new service parameters by using the
32153 @code{inherit} feature that @code{define-record-type*} provides.
32155 @xref{Using the Configuration System}, for example usage.
32159 Next comes the programming interface for service types. This is
32160 something you want to know when writing new service definitions, but not
32161 necessarily when simply looking for ways to customize your
32162 @code{operating-system} declaration.
32164 @deftp {Data Type} service-type
32165 @cindex service type
32166 This is the representation of a @dfn{service type} (@pxref{Service Types
32171 This is a symbol, used only to simplify inspection and debugging.
32173 @item @code{extensions}
32174 A non-empty list of @code{<service-extension>} objects (see below).
32176 @item @code{compose} (default: @code{#f})
32177 If this is @code{#f}, then the service type denotes services that cannot
32178 be extended---i.e., services that do not receive ``values'' from other
32181 Otherwise, it must be a one-argument procedure. The procedure is called
32182 by @code{fold-services} and is passed a list of values collected from
32183 extensions. It may return any single value.
32185 @item @code{extend} (default: @code{#f})
32186 If this is @code{#f}, services of this type cannot be extended.
32188 Otherwise, it must be a two-argument procedure: @code{fold-services}
32189 calls it, passing it the initial value of the service as the first
32190 argument and the result of applying @code{compose} to the extension
32191 values as the second argument. It must return a value that is a valid
32192 parameter value for the service instance.
32194 @item @code{description}
32195 This is a string, possibly using Texinfo markup, describing in a couple
32196 of sentences what the service is about. This string allows users to
32197 find about the service through @command{guix system search}
32198 (@pxref{Invoking guix system}).
32200 @item @code{default-value} (default: @code{&no-default-value})
32201 The default value associated for instances of this service type. This
32202 allows users to use the @code{service} form without its second argument:
32205 (service @var{type})
32208 The returned service in this case has the default value specified by
32212 @xref{Service Types and Services}, for examples.
32215 @deffn {Scheme Procedure} service-extension @var{target-type} @
32217 Return a new extension for services of type @var{target-type}.
32218 @var{compute} must be a one-argument procedure: @code{fold-services}
32219 calls it, passing it the value associated with the service that provides
32220 the extension; it must return a valid value for the target service.
32223 @deffn {Scheme Procedure} service-extension? @var{obj}
32224 Return true if @var{obj} is a service extension.
32227 Occasionally, you might want to simply extend an existing service. This
32228 involves creating a new service type and specifying the extension of
32229 interest, which can be verbose; the @code{simple-service} procedure
32230 provides a shorthand for this.
32232 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
32233 Return a service that extends @var{target} with @var{value}. This works
32234 by creating a singleton service type @var{name}, of which the returned
32235 service is an instance.
32237 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
32241 (simple-service 'my-mcron-job mcron-service-type
32242 #~(job '(next-hour (3)) "guix gc -F 2G"))
32246 At the core of the service abstraction lies the @code{fold-services}
32247 procedure, which is responsible for ``compiling'' a list of services
32248 down to a single directory that contains everything needed to boot and
32249 run the system---the directory shown by the @command{guix system build}
32250 command (@pxref{Invoking guix system}). In essence, it propagates
32251 service extensions down the service graph, updating each node parameters
32252 on the way, until it reaches the root node.
32254 @deffn {Scheme Procedure} fold-services @var{services} @
32255 [#:target-type @var{system-service-type}]
32256 Fold @var{services} by propagating their extensions down to the root of
32257 type @var{target-type}; return the root service adjusted accordingly.
32260 Lastly, the @code{(gnu services)} module also defines several essential
32261 service types, some of which are listed below.
32263 @defvr {Scheme Variable} system-service-type
32264 This is the root of the service graph. It produces the system directory
32265 as returned by the @command{guix system build} command.
32268 @defvr {Scheme Variable} boot-service-type
32269 The type of the ``boot service'', which produces the @dfn{boot script}.
32270 The boot script is what the initial RAM disk runs when booting.
32273 @defvr {Scheme Variable} etc-service-type
32274 The type of the @file{/etc} service. This service is used to create
32275 files under @file{/etc} and can be extended by
32276 passing it name/file tuples such as:
32279 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
32282 In this example, the effect would be to add an @file{/etc/issue} file
32283 pointing to the given file.
32286 @defvr {Scheme Variable} setuid-program-service-type
32287 Type for the ``setuid-program service''. This service collects lists of
32288 executable file names, passed as gexps, and adds them to the set of
32289 setuid-root programs on the system (@pxref{Setuid Programs}).
32292 @defvr {Scheme Variable} profile-service-type
32293 Type of the service that populates the @dfn{system profile}---i.e., the
32294 programs under @file{/run/current-system/profile}. Other services can
32295 extend it by passing it lists of packages to add to the system profile.
32298 @cindex provenance tracking, of the operating system
32299 @anchor{provenance-service-type}
32300 @defvr {Scheme Variable} provenance-service-type
32301 This is the type of the service that records @dfn{provenance meta-data}
32302 in the system itself. It creates several files under
32303 @file{/run/current-system}:
32307 This is a ``channel file'' that can be passed to @command{guix pull -C}
32308 or @command{guix time-machine -C}, and which describes the channels used
32309 to build the system, if that information was available
32310 (@pxref{Channels}).
32312 @item configuration.scm
32313 This is the file that was passed as the value for this
32314 @code{provenance-service-type} service. By default, @command{guix
32315 system reconfigure} automatically passes the OS configuration file it
32316 received on the command line.
32319 This contains the same information as the two other files but in a
32320 format that is more readily processable.
32323 In general, these two pieces of information (channels and configuration
32324 file) are enough to reproduce the operating system ``from source''.
32327 This information is necessary to rebuild your operating system, but it
32328 is not always sufficient. In particular, @file{configuration.scm}
32329 itself is insufficient if it is not self-contained---if it refers to
32330 external Guile modules or to extra files. If you want
32331 @file{configuration.scm} to be self-contained, we recommend that modules
32332 or files it refers to be part of a channel.
32334 Besides, provenance meta-data is ``silent'' in the sense that it does
32335 not change the bits contained in your system, @emph{except for the
32336 meta-data bits themselves}. Two different OS configurations or sets of
32337 channels can lead to the same system, bit-for-bit; when
32338 @code{provenance-service-type} is used, these two systems will have
32339 different meta-data and thus different store file names, which makes
32340 comparison less trivial.
32343 This service is automatically added to your operating system
32344 configuration when you use @command{guix system reconfigure},
32345 @command{guix system init}, or @command{guix deploy}.
32348 @node Shepherd Services
32349 @subsection Shepherd Services
32351 @cindex shepherd services
32353 @cindex init system
32354 The @code{(gnu services shepherd)} module provides a way to define
32355 services managed by the GNU@tie{}Shepherd, which is the
32356 initialization system---the first process that is started when the
32357 system boots, also known as PID@tie{}1
32358 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
32360 Services in the Shepherd can depend on each other. For instance, the
32361 SSH daemon may need to be started after the syslog daemon has been
32362 started, which in turn can only happen once all the file systems have
32363 been mounted. The simple operating system defined earlier (@pxref{Using
32364 the Configuration System}) results in a service graph like this:
32366 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
32368 You can actually generate such a graph for any operating system
32369 definition using the @command{guix system shepherd-graph} command
32370 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
32372 The @code{%shepherd-root-service} is a service object representing
32373 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
32374 by passing it lists of @code{<shepherd-service>} objects.
32376 @deftp {Data Type} shepherd-service
32377 The data type representing a service managed by the Shepherd.
32380 @item @code{provision}
32381 This is a list of symbols denoting what the service provides.
32383 These are the names that may be passed to @command{herd start},
32384 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
32385 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
32386 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
32388 @item @code{requirement} (default: @code{'()})
32389 List of symbols denoting the Shepherd services this one depends on.
32391 @cindex one-shot services, for the Shepherd
32392 @item @code{one-shot?} (default: @code{#f})
32393 Whether this service is @dfn{one-shot}. One-shot services stop immediately
32394 after their @code{start} action has completed. @xref{Slots of services,,,
32395 shepherd, The GNU Shepherd Manual}, for more info.
32397 @item @code{respawn?} (default: @code{#t})
32398 Whether to restart the service when it stops, for instance when the
32399 underlying process dies.
32402 @itemx @code{stop} (default: @code{#~(const #f)})
32403 The @code{start} and @code{stop} fields refer to the Shepherd's
32404 facilities to start and stop processes (@pxref{Service De- and
32405 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
32406 G-expressions that get expanded in the Shepherd configuration file
32407 (@pxref{G-Expressions}).
32409 @item @code{actions} (default: @code{'()})
32410 @cindex actions, of Shepherd services
32411 This is a list of @code{shepherd-action} objects (see below) defining
32412 @dfn{actions} supported by the service, in addition to the standard
32413 @code{start} and @code{stop} actions. Actions listed here become available as
32414 @command{herd} sub-commands:
32417 herd @var{action} @var{service} [@var{arguments}@dots{}]
32420 @item @code{auto-start?} (default: @code{#t})
32421 Whether this service should be started automatically by the Shepherd. If it
32422 is @code{#f} the service has to be started manually with @code{herd start}.
32424 @item @code{documentation}
32425 A documentation string, as shown when running:
32428 herd doc @var{service-name}
32431 where @var{service-name} is one of the symbols in @code{provision}
32432 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
32434 @item @code{modules} (default: @code{%default-modules})
32435 This is the list of modules that must be in scope when @code{start} and
32436 @code{stop} are evaluated.
32441 @deftp {Data Type} shepherd-action
32442 This is the data type that defines additional actions implemented by a
32443 Shepherd service (see above).
32447 Symbol naming the action.
32449 @item documentation
32450 This is a documentation string for the action. It can be viewed by running:
32453 herd doc @var{service} action @var{action}
32457 This should be a gexp that evaluates to a procedure of at least one argument,
32458 which is the ``running value'' of the service (@pxref{Slots of services,,,
32459 shepherd, The GNU Shepherd Manual}).
32462 The following example defines an action called @code{say-hello} that kindly
32468 (documentation "Say hi!")
32469 (procedure #~(lambda (running . args)
32470 (format #t "Hello, friend! arguments: ~s\n"
32475 Assuming this action is added to the @code{example} service, then you can do:
32478 # herd say-hello example
32479 Hello, friend! arguments: ()
32480 # herd say-hello example a b c
32481 Hello, friend! arguments: ("a" "b" "c")
32484 This, as you can see, is a fairly sophisticated way to say hello.
32485 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
32489 @defvr {Scheme Variable} shepherd-root-service-type
32490 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
32492 This is the service type that extensions target when they want to create
32493 shepherd services (@pxref{Service Types and Services}, for an example).
32494 Each extension must pass a list of @code{<shepherd-service>}.
32497 @defvr {Scheme Variable} %shepherd-root-service
32498 This service represents PID@tie{}1.
32502 @node Documentation
32503 @chapter Documentation
32505 @cindex documentation, searching for
32506 @cindex searching for documentation
32507 @cindex Info, documentation format
32509 @cindex manual pages
32510 In most cases packages installed with Guix come with documentation.
32511 There are two main documentation formats: ``Info'', a browseable
32512 hypertext format used for GNU software, and ``manual pages'' (or ``man
32513 pages''), the linear documentation format traditionally found on Unix.
32514 Info manuals are accessed with the @command{info} command or with Emacs,
32515 and man pages are accessed using @command{man}.
32517 You can look for documentation of software installed on your system by
32518 keyword. For example, the following command searches for information
32519 about ``TLS'' in Info manuals:
32523 "(emacs)Network Security" -- STARTTLS
32524 "(emacs)Network Security" -- TLS
32525 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
32526 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
32531 The command below searches for the same keyword in man pages:
32535 SSL (7) - OpenSSL SSL/TLS library
32536 certtool (1) - GnuTLS certificate tool
32540 These searches are purely local to your computer so you have the
32541 guarantee that documentation you find corresponds to what you have
32542 actually installed, you can access it off-line, and your privacy is
32545 Once you have these results, you can view the relevant documentation by
32549 $ info "(gnutls)Core TLS API"
32559 Info manuals contain sections and indices as well as hyperlinks like
32560 those found in Web pages. The @command{info} reader (@pxref{Top, Info
32561 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
32562 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
32563 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
32564 Introduction}, for an introduction to Info navigation.
32566 @node Installing Debugging Files
32567 @chapter Installing Debugging Files
32569 @cindex debugging files
32570 Program binaries, as produced by the GCC compilers for instance, are
32571 typically written in the ELF format, with a section containing
32572 @dfn{debugging information}. Debugging information is what allows the
32573 debugger, GDB, to map binary code to source code; it is required to
32574 debug a compiled program in good conditions.
32576 This chapter explains how to use separate debug info when packages
32577 provide it, and how to rebuild packages with debug info when it's
32581 * Separate Debug Info:: Installing 'debug' outputs.
32582 * Rebuilding Debug Info:: Building missing debug info.
32585 @node Separate Debug Info
32586 @section Separate Debug Info
32588 The problem with debugging information is that is takes up a fair amount
32589 of disk space. For example, debugging information for the GNU C Library
32590 weighs in at more than 60 MiB. Thus, as a user, keeping all the
32591 debugging info of all the installed programs is usually not an option.
32592 Yet, space savings should not come at the cost of an impediment to
32593 debugging---especially in the GNU system, which should make it easier
32594 for users to exert their computing freedom (@pxref{GNU Distribution}).
32596 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
32597 mechanism that allows users to get the best of both worlds: debugging
32598 information can be stripped from the binaries and stored in separate
32599 files. GDB is then able to load debugging information from those files,
32600 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
32603 The GNU distribution takes advantage of this by storing debugging
32604 information in the @code{lib/debug} sub-directory of a separate package
32605 output unimaginatively called @code{debug} (@pxref{Packages with
32606 Multiple Outputs}). Users can choose to install the @code{debug} output
32607 of a package when they need it. For instance, the following command
32608 installs the debugging information for the GNU C Library and for GNU
32612 guix install glibc:debug guile:debug
32615 GDB must then be told to look for debug files in the user's profile, by
32616 setting the @code{debug-file-directory} variable (consider setting it
32617 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
32621 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
32624 From there on, GDB will pick up debugging information from the
32625 @file{.debug} files under @file{~/.guix-profile/lib/debug}.
32627 In addition, you will most likely want GDB to be able to show the source
32628 code being debugged. To do that, you will have to unpack the source
32629 code of the package of interest (obtained with @code{guix build
32630 --source}, @pxref{Invoking guix build}), and to point GDB to that source
32631 directory using the @code{directory} command (@pxref{Source Path,
32632 @code{directory},, gdb, Debugging with GDB}).
32634 @c XXX: keep me up-to-date
32635 The @code{debug} output mechanism in Guix is implemented by the
32636 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
32637 opt-in---debugging information is available only for the packages with
32638 definitions explicitly declaring a @code{debug} output. To check
32639 whether a package has a @code{debug} output, use @command{guix package
32640 --list-available} (@pxref{Invoking guix package}).
32642 Read on for how to deal with packages lacking a @code{debug} output.
32644 @node Rebuilding Debug Info
32645 @section Rebuilding Debug Info
32647 @cindex debugging info, rebuilding
32648 As we saw above, some packages, but not all, provide debugging info in a
32649 @code{debug} output. What can you do when debugging info is missing?
32650 The @option{--with-debug-info} option provides a solution to that: it
32651 allows you to rebuild the package(s) for which debugging info is
32652 missing---and only those---and to graft those onto the application
32653 you're debugging. Thus, while it's not as fast as installing a
32654 @code{debug} output, it is relatively inexpensive.
32656 Let's illustrate that. Suppose you're experiencing a bug in Inkscape
32657 and would like to see what's going on in GLib, a library that's deep
32658 down in its dependency graph. As it turns out, GLib does not have a
32659 @code{debug} output and the backtrace GDB shows is all sadness:
32663 #0 0x00007ffff5f92190 in g_getenv ()
32664 from /gnu/store/@dots{}-glib-2.62.6/lib/libglib-2.0.so.0
32665 #1 0x00007ffff608a7d6 in gobject_init_ctor ()
32666 from /gnu/store/@dots{}-glib-2.62.6/lib/libgobject-2.0.so.0
32667 #2 0x00007ffff7fe275a in call_init (l=<optimized out>, argc=argc@@entry=1, argv=argv@@entry=0x7fffffffcfd8,
32668 env=env@@entry=0x7fffffffcfe8) at dl-init.c:72
32669 #3 0x00007ffff7fe2866 in call_init (env=0x7fffffffcfe8, argv=0x7fffffffcfd8, argc=1, l=<optimized out>)
32673 To address that, you install Inkscape linked against a variant GLib that
32674 contains debug info:
32677 guix install inkscape --with-debug-info=glib
32680 This time, debugging will be a whole lot nicer:
32683 $ gdb --args sh -c 'exec inkscape'
32686 Function "g_getenv" not defined.
32687 Make breakpoint pending on future shared library load? (y or [n]) y
32688 Breakpoint 1 (g_getenv) pending.
32690 Starting program: /gnu/store/@dots{}-profile/bin/sh -c exec\ inkscape
32693 #0 g_getenv (variable=variable@@entry=0x7ffff60c7a2e "GOBJECT_DEBUG") at ../glib-2.62.6/glib/genviron.c:252
32694 #1 0x00007ffff608a7d6 in gobject_init () at ../glib-2.62.6/gobject/gtype.c:4380
32695 #2 gobject_init_ctor () at ../glib-2.62.6/gobject/gtype.c:4493
32696 #3 0x00007ffff7fe275a in call_init (l=<optimized out>, argc=argc@@entry=3, argv=argv@@entry=0x7fffffffd088,
32697 env=env@@entry=0x7fffffffd0a8) at dl-init.c:72
32703 Note that there can be packages for which @option{--with-debug-info}
32704 will not have the desired effect. @xref{Package Transformation Options,
32705 @option{--with-debug-info}}, for more information.
32707 @node Security Updates
32708 @chapter Security Updates
32710 @cindex security updates
32711 @cindex security vulnerabilities
32712 Occasionally, important security vulnerabilities are discovered in software
32713 packages and must be patched. Guix developers try hard to keep track of
32714 known vulnerabilities and to apply fixes as soon as possible in the
32715 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
32716 containing only security updates). The @command{guix lint} tool helps
32717 developers find out about vulnerable versions of software packages in the
32722 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
32723 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
32724 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
32728 @xref{Invoking guix lint}, for more information.
32730 Guix follows a functional
32731 package management discipline (@pxref{Introduction}), which implies
32732 that, when a package is changed, @emph{every package that depends on it}
32733 must be rebuilt. This can significantly slow down the deployment of
32734 fixes in core packages such as libc or Bash, since basically the whole
32735 distribution would need to be rebuilt. Using pre-built binaries helps
32736 (@pxref{Substitutes}), but deployment may still take more time than
32740 To address this, Guix implements @dfn{grafts}, a mechanism that allows
32741 for fast deployment of critical updates without the costs associated
32742 with a whole-distribution rebuild. The idea is to rebuild only the
32743 package that needs to be patched, and then to ``graft'' it onto packages
32744 explicitly installed by the user and that were previously referring to
32745 the original package. The cost of grafting is typically very low, and
32746 order of magnitudes lower than a full rebuild of the dependency chain.
32748 @cindex replacements of packages, for grafts
32749 For instance, suppose a security update needs to be applied to Bash.
32750 Guix developers will provide a package definition for the ``fixed''
32751 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
32752 Packages}). Then, the original package definition is augmented with a
32753 @code{replacement} field pointing to the package containing the bug fix:
32760 (replacement bash-fixed)))
32763 From there on, any package depending directly or indirectly on Bash---as
32764 reported by @command{guix gc --requisites} (@pxref{Invoking guix
32765 gc})---that is installed is automatically ``rewritten'' to refer to
32766 @code{bash-fixed} instead of @code{bash}. This grafting process takes
32767 time proportional to the size of the package, usually less than a
32768 minute for an ``average'' package on a recent machine. Grafting is
32769 recursive: when an indirect dependency requires grafting, then grafting
32770 ``propagates'' up to the package that the user is installing.
32772 Currently, the length of the name and version of the graft and that of
32773 the package it replaces (@code{bash-fixed} and @code{bash} in the example
32774 above) must be equal. This restriction mostly comes from the fact that
32775 grafting works by patching files, including binary files, directly.
32776 Other restrictions may apply: for instance, when adding a graft to a
32777 package providing a shared library, the original shared library and its
32778 replacement must have the same @code{SONAME} and be binary-compatible.
32780 The @option{--no-grafts} command-line option allows you to forcefully
32781 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
32785 guix build bash --no-grafts
32789 returns the store file name of the original Bash, whereas:
32796 returns the store file name of the ``fixed'', replacement Bash. This
32797 allows you to distinguish between the two variants of Bash.
32799 To verify which Bash your whole profile refers to, you can run
32800 (@pxref{Invoking guix gc}):
32803 guix gc -R `readlink -f ~/.guix-profile` | grep bash
32807 @dots{} and compare the store file names that you get with those above.
32808 Likewise for a complete Guix system generation:
32811 guix gc -R `guix system build my-config.scm` | grep bash
32814 Lastly, to check which Bash running processes are using, you can use the
32815 @command{lsof} command:
32818 lsof | grep /gnu/store/.*bash
32822 @node Bootstrapping
32823 @chapter Bootstrapping
32825 @c Adapted from the ELS 2013 paper.
32827 @cindex bootstrapping
32829 Bootstrapping in our context refers to how the distribution gets built
32830 ``from nothing''. Remember that the build environment of a derivation
32831 contains nothing but its declared inputs (@pxref{Introduction}). So
32832 there's an obvious chicken-and-egg problem: how does the first package
32833 get built? How does the first compiler get compiled?
32835 It is tempting to think of this question as one that only die-hard
32836 hackers may care about. However, while the answer to that question is
32837 technical in nature, its implications are wide-ranging. How the
32838 distribution is bootstrapped defines the extent to which we, as
32839 individuals and as a collective of users and hackers, can trust the
32840 software we run. It is a central concern from the standpoint of
32841 @emph{security} and from a @emph{user freedom} viewpoint.
32843 @cindex bootstrap binaries
32844 The GNU system is primarily made of C code, with libc at its core. The
32845 GNU build system itself assumes the availability of a Bourne shell and
32846 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
32847 `grep'. Furthermore, build programs---programs that run
32848 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
32849 (@pxref{Derivations}). Consequently, to be able to build anything at
32850 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
32851 Binutils, libc, and the other packages mentioned above---the
32852 @dfn{bootstrap binaries}.
32854 These bootstrap binaries are ``taken for granted'', though we can also
32855 re-create them if needed (@pxref{Preparing to Use the Bootstrap
32859 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
32860 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
32863 @node Reduced Binary Seed Bootstrap
32864 @section The Reduced Binary Seed Bootstrap
32866 Guix---like other GNU/Linux distributions---is traditionally bootstrapped from
32867 a set of bootstrap binaries: Bourne shell, command-line tools provided by GNU
32868 Coreutils, Awk, Findutils, `sed', and `grep' and Guile, GCC, Binutils, and the
32869 GNU C Library (@pxref{Bootstrapping}). Usually, these bootstrap binaries are
32870 ``taken for granted.''
32872 Taking the bootstrap binaries for granted means that we consider them to
32873 be a correct and trustworthy ``seed'' for building the complete system.
32874 Therein lies a problem: the combined size of these bootstrap binaries is
32875 about 250MB (@pxref{Bootstrappable Builds,,, mes, GNU Mes}). Auditing
32876 or even inspecting these is next to impossible.
32878 For @code{i686-linux} and @code{x86_64-linux}, Guix now features a
32879 ``Reduced Binary Seed'' bootstrap @footnote{We would like to say: ``Full
32880 Source Bootstrap'' and while we are working towards that goal it would
32881 be hyperbole to use that term for what we do now.}.
32883 The Reduced Binary Seed bootstrap removes the most critical tools---from a
32884 trust perspective---from the bootstrap binaries: GCC, Binutils and the GNU C
32885 Library are replaced by: @code{bootstrap-mescc-tools} (a tiny assembler and
32886 linker) and @code{bootstrap-mes} (a small Scheme Interpreter and a C compiler
32887 written in Scheme and the Mes C Library, built for TinyCC and for GCC).
32889 Using these new binary seeds the ``missing'' Binutils, GCC, and the GNU
32890 C Library are built from source. From here on the more traditional
32891 bootstrap process resumes. This approach has reduced the bootstrap
32892 binaries in size to about 145MB in Guix v1.1.
32894 The next step that Guix has taken is to replace the shell and all its
32895 utilities with implementations in Guile Scheme, the @emph{Scheme-only
32896 bootstrap}. Gash (@pxref{Gash,,, gash, The Gash manual}) is a
32897 POSIX-compatible shell that replaces Bash, and it comes with Gash Utils
32898 which has minimalist replacements for Awk, the GNU Core Utilities, Grep,
32899 Gzip, Sed, and Tar. The rest of the bootstrap binary seeds that were
32900 removed are now built from source.
32902 Building the GNU System from source is currently only possibly by adding
32903 some historical GNU packages as intermediate steps@footnote{Packages
32904 such as @code{gcc-2.95.3}, @code{binutils-2.14}, @code{glibc-2.2.5},
32905 @code{gzip-1.2.4}, @code{tar-1.22}, and some others. For details, see
32906 @file{gnu/packages/commencement.scm}.}. As Gash and Gash Utils mature,
32907 and GNU packages become more bootstrappable again (e.g., new releases of
32908 GNU Sed will also ship as gzipped tarballs again, as alternative to the
32909 hard to bootstrap @code{xz}-compression), this set of added packages can
32910 hopefully be reduced again.
32912 The graph below shows the resulting dependency graph for
32913 @code{gcc-core-mesboot0}, the bootstrap compiler used for the
32914 traditional bootstrap of the rest of the Guix System.
32916 @c ./pre-inst-env guix graph -e '(@@ (gnu packages commencement) gcc-core-mesboot0)' | sed -re 's,((bootstrap-mescc-tools|bootstrap-mes|guile-bootstrap).*shape =) box,\1 ellipse,' > doc/images/gcc-core-mesboot0-graph.dot
32917 @image{images/gcc-core-mesboot0-graph,6in,,Dependency graph of gcc-core-mesboot0}
32919 The only significant binary bootstrap seeds that remain@footnote{
32920 Ignoring the 68KB @code{mescc-tools}; that will be removed later,
32921 together with @code{mes}.} are a Scheme intepreter and a Scheme
32922 compiler: GNU Mes and GNU Guile@footnote{Not shown in this graph are the
32923 static binaries for @file{bash}, @code{tar}, and @code{xz} that are used
32924 to get Guile running.}.
32926 This further reduction has brought down the size of the binary seed to
32927 about 60MB for @code{i686-linux} and @code{x86_64-linux}.
32929 Work is ongoing to remove all binary blobs from our free software
32930 bootstrap stack, working towards a Full Source Bootstrap. Also ongoing
32931 is work to bring these bootstraps to the @code{arm-linux} and
32932 @code{aarch64-linux} architectures and to the Hurd.
32934 If you are interested, join us on @samp{#bootstrappable} on the Freenode
32935 IRC network or discuss on @email{bug-mes@@gnu.org} or
32936 @email{gash-devel@@nongnu.org}.
32938 @node Preparing to Use the Bootstrap Binaries
32939 @section Preparing to Use the Bootstrap Binaries
32941 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
32942 @c large image, it's hard to scroll. Oh well.
32943 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
32945 The figure above shows the very beginning of the dependency graph of the
32946 distribution, corresponding to the package definitions of the @code{(gnu
32947 packages bootstrap)} module. A similar figure can be generated with
32948 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
32951 guix graph -t derivation \
32952 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
32953 | dot -Tps > gcc.ps
32956 or, for the further Reduced Binary Seed bootstrap
32959 guix graph -t derivation \
32960 -e '(@@@@ (gnu packages bootstrap) %bootstrap-mes)' \
32961 | dot -Tps > mes.ps
32964 At this level of detail, things are
32965 slightly complex. First, Guile itself consists of an ELF executable,
32966 along with many source and compiled Scheme files that are dynamically
32967 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
32968 tarball shown in this graph. This tarball is part of Guix's ``source''
32969 distribution, and gets inserted into the store with @code{add-to-store}
32970 (@pxref{The Store}).
32972 But how do we write a derivation that unpacks this tarball and adds it
32973 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
32974 derivation---the first one that gets built---uses @code{bash} as its
32975 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
32976 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
32977 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
32978 the Guix source distribution, whose sole purpose is to allow the Guile
32979 tarball to be unpacked.
32981 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
32982 Guile that can be used to run subsequent build programs. Its first task
32983 is to download tarballs containing the other pre-built binaries---this
32984 is what the @file{.tar.xz.drv} derivations do. Guix modules such as
32985 @code{ftp-client.scm} are used for this purpose. The
32986 @code{module-import.drv} derivations import those modules in a directory
32987 in the store, using the original layout. The
32988 @code{module-import-compiled.drv} derivations compile those modules, and
32989 write them in an output directory with the right layout. This
32990 corresponds to the @code{#:modules} argument of
32991 @code{build-expression->derivation} (@pxref{Derivations}).
32993 Finally, the various tarballs are unpacked by the derivations
32994 @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv}, or
32995 @code{bootstrap-mes-0.drv} and @code{bootstrap-mescc-tools-0.drv}, at which
32996 point we have a working C tool chain.
32998 @unnumberedsec Building the Build Tools
33000 Bootstrapping is complete when we have a full tool chain that does not
33001 depend on the pre-built bootstrap tools discussed above. This
33002 no-dependency requirement is verified by checking whether the files of
33003 the final tool chain contain references to the @file{/gnu/store}
33004 directories of the bootstrap inputs. The process that leads to this
33005 ``final'' tool chain is described by the package definitions found in
33006 the @code{(gnu packages commencement)} module.
33008 The @command{guix graph} command allows us to ``zoom out'' compared to
33009 the graph above, by looking at the level of package objects instead of
33010 individual derivations---remember that a package may translate to
33011 several derivations, typically one derivation to download its source,
33012 one to build the Guile modules it needs, and one to actually build the
33013 package from source. The command:
33016 guix graph -t bag \
33017 -e '(@@@@ (gnu packages commencement)
33018 glibc-final-with-bootstrap-bash)' | xdot -
33022 displays the dependency graph leading to the ``final'' C
33023 library@footnote{You may notice the @code{glibc-intermediate} label,
33024 suggesting that it is not @emph{quite} final, but as a good
33025 approximation, we will consider it final.}, depicted below.
33027 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
33029 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
33030 The first tool that gets built with the bootstrap binaries is
33031 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
33032 for all the following packages. From there Findutils and Diffutils get
33035 Then come the first-stage Binutils and GCC, built as pseudo cross
33036 tools---i.e., with @option{--target} equal to @option{--host}. They are
33037 used to build libc. Thanks to this cross-build trick, this libc is
33038 guaranteed not to hold any reference to the initial tool chain.
33040 From there the final Binutils and GCC (not shown above) are built. GCC
33041 uses @command{ld} from the final Binutils, and links programs against
33042 the just-built libc. This tool chain is used to build the other
33043 packages used by Guix and by the GNU Build System: Guile, Bash,
33046 And voilà! At this point we have the complete set of build tools that
33047 the GNU Build System expects. These are in the @code{%final-inputs}
33048 variable of the @code{(gnu packages commencement)} module, and are
33049 implicitly used by any package that uses @code{gnu-build-system}
33050 (@pxref{Build Systems, @code{gnu-build-system}}).
33053 @unnumberedsec Building the Bootstrap Binaries
33055 @cindex bootstrap binaries
33056 Because the final tool chain does not depend on the bootstrap binaries,
33057 those rarely need to be updated. Nevertheless, it is useful to have an
33058 automated way to produce them, should an update occur, and this is what
33059 the @code{(gnu packages make-bootstrap)} module provides.
33061 The following command builds the tarballs containing the bootstrap binaries
33062 (Binutils, GCC, glibc, for the traditional bootstrap and linux-libre-headers,
33063 bootstrap-mescc-tools, bootstrap-mes for the Reduced Binary Seed bootstrap,
33064 and Guile, and a tarball containing a mixture of Coreutils and other basic
33065 command-line tools):
33068 guix build bootstrap-tarballs
33071 The generated tarballs are those that should be referred to in the
33072 @code{(gnu packages bootstrap)} module mentioned at the beginning of
33075 Still here? Then perhaps by now you've started to wonder: when do we
33076 reach a fixed point? That is an interesting question! The answer is
33077 unknown, but if you would like to investigate further (and have
33078 significant computational and storage resources to do so), then let us
33081 @unnumberedsec Reducing the Set of Bootstrap Binaries
33083 Our traditional bootstrap includes GCC, GNU Libc, Guile, etc. That's a lot of
33084 binary code! Why is that a problem? It's a problem because these big chunks
33085 of binary code are practically non-auditable, which makes it hard to establish
33086 what source code produced them. Every unauditable binary also leaves us
33087 vulnerable to compiler backdoors as described by Ken Thompson in the 1984
33088 paper @emph{Reflections on Trusting Trust}.
33090 This is mitigated by the fact that our bootstrap binaries were generated
33091 from an earlier Guix revision. Nevertheless it lacks the level of
33092 transparency that we get in the rest of the package dependency graph,
33093 where Guix always gives us a source-to-binary mapping. Thus, our goal
33094 is to reduce the set of bootstrap binaries to the bare minimum.
33096 The @uref{https://bootstrappable.org, Bootstrappable.org web site} lists
33097 on-going projects to do that. One of these is about replacing the
33098 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
33099 of increasing complexity, which could be built from source starting from
33100 a simple and auditable assembler.
33102 Our first major achievement is the replacement of of GCC, the GNU C Library
33103 and Binutils by MesCC-Tools (a simple hex linker and macro assembler) and Mes
33104 (@pxref{Top, GNU Mes Reference Manual,, mes, GNU Mes}, a Scheme interpreter
33105 and C compiler in Scheme). Neither MesCC-Tools nor Mes can be fully
33106 bootstrapped yet and thus we inject them as binary seeds. We call this the
33107 Reduced Binary Seed bootstrap, as it has halved the size of our bootstrap
33108 binaries! Also, it has eliminated the C compiler binary; i686-linux and
33109 x86_64-linux Guix packages are now bootstrapped without any binary C compiler.
33111 Work is ongoing to make MesCC-Tools and Mes fully bootstrappable and we are
33112 also looking at any other bootstrap binaries. Your help is welcome!
33115 @chapter Porting to a New Platform
33117 As discussed above, the GNU distribution is self-contained, and
33118 self-containment is achieved by relying on pre-built ``bootstrap
33119 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
33120 operating system kernel, CPU architecture, and application binary
33121 interface (ABI). Thus, to port the distribution to a platform that is
33122 not yet supported, one must build those bootstrap binaries, and update
33123 the @code{(gnu packages bootstrap)} module to use them on that platform.
33125 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
33126 When everything goes well, and assuming the GNU tool chain supports the
33127 target platform, this can be as simple as running a command like this
33131 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
33134 For this to work, the @code{glibc-dynamic-linker} procedure in
33135 @code{(gnu packages bootstrap)} must be augmented to return the right
33136 file name for libc's dynamic linker on that platform; likewise,
33137 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
33138 taught about the new platform.
33140 Once these are built, the @code{(gnu packages bootstrap)} module needs
33141 to be updated to refer to these binaries on the target platform. That
33142 is, the hashes and URLs of the bootstrap tarballs for the new platform
33143 must be added alongside those of the currently supported platforms. The
33144 bootstrap Guile tarball is treated specially: it is expected to be
33145 available locally, and @file{gnu/local.mk} has rules to download it for
33146 the supported architectures; a rule for the new platform must be added
33149 In practice, there may be some complications. First, it may be that the
33150 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
33151 above) is not recognized by all the GNU tools. Typically, glibc
33152 recognizes some of these, whereas GCC uses an extra @option{--with-abi}
33153 configure flag (see @code{gcc.scm} for examples of how to handle this).
33154 Second, some of the required packages could fail to build for that
33155 platform. Lastly, the generated binaries could be broken for some
33158 @c *********************************************************************
33159 @include contributing.texi
33161 @c *********************************************************************
33162 @node Acknowledgments
33163 @chapter Acknowledgments
33165 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
33166 which was designed and
33167 implemented by Eelco Dolstra, with contributions from other people (see
33168 the @file{nix/AUTHORS} file in Guix). Nix pioneered functional package
33169 management, and promoted unprecedented features, such as transactional
33170 package upgrades and rollbacks, per-user profiles, and referentially
33171 transparent build processes. Without this work, Guix would not exist.
33173 The Nix-based software distributions, Nixpkgs and NixOS, have also been
33174 an inspiration for Guix.
33176 GNU@tie{}Guix itself is a collective work with contributions from a
33177 number of people. See the @file{AUTHORS} file in Guix for more
33178 information on these fine people. The @file{THANKS} file lists people
33179 who have helped by reporting bugs, taking care of the infrastructure,
33180 providing artwork and themes, making suggestions, and more---thank you!
33183 @c *********************************************************************
33184 @node GNU Free Documentation License
33185 @appendix GNU Free Documentation License
33186 @cindex license, GNU Free Documentation License
33187 @include fdl-1.3.texi
33189 @c *********************************************************************
33190 @node Concept Index
33191 @unnumbered Concept Index
33194 @node Programming Index
33195 @unnumbered Programming Index
33196 @syncodeindex tp fn
33197 @syncodeindex vr fn
33202 @c Local Variables:
33203 @c ispell-local-dictionary: "american";