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, 2021 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, 2021 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, 2021 Chris Marusich@*
35 Copyright @copyright{} 2016, 2017, 2018, 2019, 2020, 2021 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, 2020, 2021 Christopher Baines@*
42 Copyright @copyright{} 2017, 2018, 2019 Clément Lassieur@*
43 Copyright @copyright{} 2017, 2018, 2020, 2021 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, 2021 Christopher Lemmer Webber@*
49 Copyright @copyright{} 2017, 2018, 2019, 2020 Marius Bakke@*
50 Copyright @copyright{} 2017, 2019, 2020 Hartmut Goebel@*
51 Copyright @copyright{} 2017, 2019, 2020, 2021 Maxim Cournoyer@*
52 Copyright @copyright{} 2017, 2018, 2019, 2020, 2021 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, 2021 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, 2021 Alexandru-Sergiu Marton@*
85 Copyright @copyright{} 2020 raingloom@*
86 Copyright @copyright{} 2020 Daniel Brooks@*
87 Copyright @copyright{} 2020 John Soo@*
88 Copyright @copyright{} 2020 Jonathan Brielmaier@*
89 Copyright @copyright{} 2020 Edgar Vincent@*
90 Copyright @copyright{} 2021 Maxime Devos@*
92 Permission is granted to copy, distribute and/or modify this document
93 under the terms of the GNU Free Documentation License, Version 1.3 or
94 any later version published by the Free Software Foundation; with no
95 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
96 copy of the license is included in the section entitled ``GNU Free
97 Documentation License''.
100 @dircategory System administration
102 * Guix: (guix). Manage installed software and system configuration.
103 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
104 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
105 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
106 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
107 * guix deploy: (guix)Invoking guix deploy. Manage operating system configurations for remote hosts.
110 @dircategory Software development
112 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
113 * guix build: (guix)Invoking guix build. Building packages.
114 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
118 @title GNU Guix Reference Manual
119 @subtitle Using the GNU Guix Functional Package Manager
120 @author The GNU Guix Developers
123 @vskip 0pt plus 1filll
124 Edition @value{EDITION} @*
132 @c *********************************************************************
136 This document describes GNU Guix version @value{VERSION}, a functional
137 package management tool written for the GNU system.
139 @c TRANSLATORS: You can replace the following paragraph with information on
140 @c how to join your own translation team and how to report issues with the
142 This manual is also available in Simplified Chinese (@pxref{Top,,, guix.zh_CN,
143 GNU Guix参考手册}), French (@pxref{Top,,, guix.fr, Manuel de référence de GNU
144 Guix}), German (@pxref{Top,,, guix.de, Referenzhandbuch zu GNU Guix}),
145 Spanish (@pxref{Top,,, guix.es, Manual de referencia de GNU Guix}), and
146 Russian (@pxref{Top,,, guix.ru, Руководство GNU Guix}). If you
147 would like to translate it in your native language, consider joining
148 @uref{https://translate.fedoraproject.org/projects/guix/documentation-manual,
152 * Introduction:: What is Guix about?
153 * Installation:: Installing Guix.
154 * System Installation:: Installing the whole operating system.
155 * Getting Started:: Your first steps.
156 * Package Management:: Package installation, upgrade, etc.
157 * Channels:: Customizing the package collection.
158 * Development:: Guix-aided software development.
159 * Programming Interface:: Using Guix in Scheme.
160 * Utilities:: Package management commands.
161 * System Configuration:: Configuring the operating system.
162 * Documentation:: Browsing software user manuals.
163 * Installing Debugging Files:: Feeding the debugger.
164 * Security Updates:: Deploying security fixes quickly.
165 * Bootstrapping:: GNU/Linux built from scratch.
166 * Porting:: Targeting another platform or kernel.
167 * Contributing:: Your help needed!
169 * Acknowledgments:: Thanks!
170 * GNU Free Documentation License:: The license of this manual.
171 * Concept Index:: Concepts.
172 * Programming Index:: Data types, functions, and variables.
175 --- The Detailed Node Listing ---
179 * Managing Software the Guix Way:: What's special.
180 * GNU Distribution:: The packages and tools.
184 * Binary Installation:: Getting Guix running in no time!
185 * Requirements:: Software needed to build and run Guix.
186 * Running the Test Suite:: Testing Guix.
187 * Setting Up the Daemon:: Preparing the build daemon's environment.
188 * Invoking guix-daemon:: Running the build daemon.
189 * Application Setup:: Application-specific setup.
190 * Upgrading Guix:: Upgrading Guix and its build daemon.
192 Setting Up the Daemon
194 * Build Environment Setup:: Preparing the isolated build environment.
195 * Daemon Offload Setup:: Offloading builds to remote machines.
196 * SELinux Support:: Using an SELinux policy for the daemon.
200 * Limitations:: What you can expect.
201 * Hardware Considerations:: Supported hardware.
202 * USB Stick and DVD Installation:: Preparing the installation medium.
203 * Preparing for Installation:: Networking, partitioning, etc.
204 * Guided Graphical Installation:: Easy graphical installation.
205 * Manual Installation:: Manual installation for wizards.
206 * After System Installation:: When installation succeeded.
207 * Installing Guix in a VM:: Guix System playground.
208 * Building the Installation Image:: How this comes to be.
212 * Keyboard Layout and Networking and Partitioning:: Initial setup.
213 * Proceeding with the Installation:: Installing.
217 * Features:: How Guix will make your life brighter.
218 * Invoking guix package:: Package installation, removal, etc.
219 * Substitutes:: Downloading pre-built binaries.
220 * Packages with Multiple Outputs:: Single source package, multiple outputs.
221 * Invoking guix gc:: Running the garbage collector.
222 * Invoking guix pull:: Fetching the latest Guix and distribution.
223 * Invoking guix time-machine:: Running an older revision of Guix.
224 * Inferiors:: Interacting with another revision of Guix.
225 * Invoking guix describe:: Display information about your Guix revision.
226 * Invoking guix archive:: Exporting and importing store files.
230 * Official Substitute Server:: One particular source of substitutes.
231 * Substitute Server Authorization:: How to enable or disable substitutes.
232 * Getting Substitutes from Other Servers:: Substitute diversity.
233 * Substitute Authentication:: How Guix verifies substitutes.
234 * Proxy Settings:: How to get substitutes via proxy.
235 * Substitution Failure:: What happens when substitution fails.
236 * On Trusting Binaries:: How can you trust that binary blob?
240 * Specifying Additional Channels:: Extending the package collection.
241 * Using a Custom Guix Channel:: Using a customized Guix.
242 * Replicating Guix:: Running the @emph{exact same} Guix.
243 * Channel Authentication:: How Guix verifies what it fetches.
244 * Channels with Substitutes:: Using channels with available substitutes.
245 * Creating a Channel:: How to write your custom channel.
246 * Package Modules in a Sub-directory:: Specifying the channel's package modules location.
247 * Declaring Channel Dependencies:: How to depend on other channels.
248 * Specifying Channel Authorizations:: Defining channel authors authorizations.
249 * Primary URL:: Distinguishing mirror to original.
250 * Writing Channel News:: Communicating information to channel's users.
254 * Invoking guix environment:: Setting up development environments.
255 * Invoking guix pack:: Creating software bundles.
256 * The GCC toolchain:: Working with languages supported by GCC.
257 * Invoking guix git authenticate:: Authenticating Git repositories.
259 Programming Interface
261 * Package Modules:: Packages from the programmer's viewpoint.
262 * Defining Packages:: Defining new packages.
263 * Defining Package Variants:: Customizing packages.
264 * Build Systems:: Specifying how packages are built.
265 * Build Phases:: Phases of the build process of a package.
266 * Build Utilities:: Helpers for your package definitions and more.
267 * The Store:: Manipulating the package store.
268 * Derivations:: Low-level interface to package derivations.
269 * The Store Monad:: Purely functional interface to the store.
270 * G-Expressions:: Manipulating build expressions.
271 * Invoking guix repl:: Programming Guix in Guile.
275 * package Reference:: The package data type.
276 * origin Reference:: The origin data type.
280 * Invoking guix build:: Building packages from the command line.
281 * Invoking guix edit:: Editing package definitions.
282 * Invoking guix download:: Downloading a file and printing its hash.
283 * Invoking guix hash:: Computing the cryptographic hash of a file.
284 * Invoking guix import:: Importing package definitions.
285 * Invoking guix refresh:: Updating package definitions.
286 * Invoking guix lint:: Finding errors in package definitions.
287 * Invoking guix size:: Profiling disk usage.
288 * Invoking guix graph:: Visualizing the graph of packages.
289 * Invoking guix publish:: Sharing substitutes.
290 * Invoking guix challenge:: Challenging substitute servers.
291 * Invoking guix copy:: Copying to and from a remote store.
292 * Invoking guix container:: Process isolation.
293 * Invoking guix weather:: Assessing substitute availability.
294 * Invoking guix processes:: Listing client processes.
296 Invoking @command{guix build}
298 * Common Build Options:: Build options for most commands.
299 * Package Transformation Options:: Creating variants of packages.
300 * Additional Build Options:: Options specific to 'guix build'.
301 * Debugging Build Failures:: Real life packaging experience.
305 * Using the Configuration System:: Customizing your GNU system.
306 * operating-system Reference:: Detail of operating-system declarations.
307 * File Systems:: Configuring file system mounts.
308 * Mapped Devices:: Block device extra processing.
309 * User Accounts:: Specifying user accounts.
310 * Keyboard Layout:: How the system interprets key strokes.
311 * Locales:: Language and cultural convention settings.
312 * Services:: Specifying system services.
313 * Setuid Programs:: Programs running with root privileges.
314 * X.509 Certificates:: Authenticating HTTPS servers.
315 * Name Service Switch:: Configuring libc's name service switch.
316 * Initial RAM Disk:: Linux-Libre bootstrapping.
317 * Bootloader Configuration:: Configuring the boot loader.
318 * Invoking guix system:: Instantiating a system configuration.
319 * Invoking guix deploy:: Deploying a system configuration to a remote host.
320 * Running Guix in a VM:: How to run Guix System in a virtual machine.
321 * Defining Services:: Adding new service definitions.
325 * Base Services:: Essential system services.
326 * Scheduled Job Execution:: The mcron service.
327 * Log Rotation:: The rottlog service.
328 * Networking Services:: Network setup, SSH daemon, etc.
329 * Unattended Upgrades:: Automated system upgrades.
330 * X Window:: Graphical display.
331 * Printing Services:: Local and remote printer support.
332 * Desktop Services:: D-Bus and desktop services.
333 * Sound Services:: ALSA and Pulseaudio services.
334 * Database Services:: SQL databases, key-value stores, etc.
335 * Mail Services:: IMAP, POP3, SMTP, and all that.
336 * Messaging Services:: Messaging services.
337 * Telephony Services:: Telephony services.
338 * Monitoring Services:: Monitoring services.
339 * Kerberos Services:: Kerberos services.
340 * LDAP Services:: LDAP services.
341 * Web Services:: Web servers.
342 * Certificate Services:: TLS certificates via Let's Encrypt.
343 * DNS Services:: DNS daemons.
344 * VPN Services:: VPN daemons.
345 * Network File System:: NFS related services.
346 * Continuous Integration:: Cuirass and Laminar services.
347 * Power Management Services:: Extending battery life.
348 * Audio Services:: The MPD.
349 * Virtualization Services:: Virtualization services.
350 * Version Control Services:: Providing remote access to Git repositories.
351 * Game Services:: Game servers.
352 * PAM Mount Service:: Service to mount volumes when logging in.
353 * Guix Services:: Services relating specifically to Guix.
354 * Linux Services:: Services tied to the Linux kernel.
355 * Hurd Services:: Services specific for a Hurd System.
356 * Miscellaneous Services:: Other services.
360 * Service Composition:: The model for composing services.
361 * Service Types and Services:: Types and services.
362 * Service Reference:: API reference.
363 * Shepherd Services:: A particular type of service.
365 Installing Debugging Files
367 * Separate Debug Info:: Installing 'debug' outputs.
368 * Rebuilding Debug Info:: Building missing debug info.
372 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
373 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
378 @c *********************************************************************
380 @chapter Introduction
383 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
384 using the international phonetic alphabet (IPA).} is a package
385 management tool for and distribution of the GNU system.
386 Guix makes it easy for unprivileged
387 users to install, upgrade, or remove software packages, to roll back to a
388 previous package set, to build packages from source, and generally
389 assists with the creation and maintenance of software environments.
392 @cindex GuixSD, now Guix System
393 @cindex Guix System Distribution, now Guix System
394 You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
395 complements the available tools without interference (@pxref{Installation}),
396 or you can use it as a standalone operating system distribution,
397 @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
398 System Distribution'' or ``GuixSD''. We now consider it makes more sense to
399 group everything under the ``Guix'' banner since, after all, Guix System is
400 readily available through the @command{guix system} command, even if you're
401 using a different distro underneath!}. @xref{GNU Distribution}.
404 * Managing Software the Guix Way:: What's special.
405 * GNU Distribution:: The packages and tools.
408 @node Managing Software the Guix Way
409 @section Managing Software the Guix Way
411 @cindex user interfaces
412 Guix provides a command-line package management interface
413 (@pxref{Package Management}), tools to help with software development
414 (@pxref{Development}), command-line utilities for more advanced usage
415 (@pxref{Utilities}), as well as Scheme programming interfaces
416 (@pxref{Programming Interface}).
418 Its @dfn{build daemon} is responsible for building packages on behalf of
419 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
420 binaries from authorized sources (@pxref{Substitutes}).
422 @cindex extensibility of the distribution
423 @cindex customization, of packages
424 Guix includes package definitions for many GNU and non-GNU packages, all
425 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
426 user's computing freedom}. It is @emph{extensible}: users can write
427 their own package definitions (@pxref{Defining Packages}) and make them
428 available as independent package modules (@pxref{Package Modules}). It
429 is also @emph{customizable}: users can @emph{derive} specialized package
430 definitions from existing ones, including from the command line
431 (@pxref{Package Transformation Options}).
433 @cindex functional package management
435 Under the hood, Guix implements the @dfn{functional package management}
436 discipline pioneered by Nix (@pxref{Acknowledgments}).
437 In Guix, the package build and installation process is seen
438 as a @emph{function}, in the mathematical sense. That function takes inputs,
439 such as build scripts, a compiler, and libraries, and
440 returns an installed package. As a pure function, its result depends
441 solely on its inputs---for instance, it cannot refer to software or
442 scripts that were not explicitly passed as inputs. A build function
443 always produces the same result when passed a given set of inputs. It
444 cannot alter the environment of the running system in
445 any way; for instance, it cannot create, modify, or delete files outside
446 of its build and installation directories. This is achieved by running
447 build processes in isolated environments (or @dfn{containers}), where only their
448 explicit inputs are visible.
451 The result of package build functions is @dfn{cached} in the file
452 system, in a special directory called @dfn{the store} (@pxref{The
453 Store}). Each package is installed in a directory of its own in the
454 store---by default under @file{/gnu/store}. The directory name contains
455 a hash of all the inputs used to build that package; thus, changing an
456 input yields a different directory name.
458 This approach is the foundation for the salient features of Guix: support
459 for transactional package upgrade and rollback, per-user installation, and
460 garbage collection of packages (@pxref{Features}).
463 @node GNU Distribution
464 @section GNU Distribution
467 Guix comes with a distribution of the GNU system consisting entirely of
468 free software@footnote{The term ``free'' here refers to the
469 @url{https://www.gnu.org/philosophy/free-sw.html,freedom provided to
470 users of that software}.}. The
471 distribution can be installed on its own (@pxref{System Installation}),
472 but it is also possible to install Guix as a package manager on top of
473 an installed GNU/Linux system (@pxref{Installation}). When we need to
474 distinguish between the two, we refer to the standalone distribution as
477 The distribution provides core GNU packages such as GNU libc, GCC, and
478 Binutils, as well as many GNU and non-GNU applications. The complete
479 list of available packages can be browsed
480 @url{https://www.gnu.org/software/guix/packages,on-line} or by
481 running @command{guix package} (@pxref{Invoking guix package}):
484 guix package --list-available
487 Our goal is to provide a practical 100% free software distribution of
488 Linux-based and other variants of GNU, with a focus on the promotion and
489 tight integration of GNU components, and an emphasis on programs and
490 tools that help users exert that freedom.
492 Packages are currently available on the following platforms:
497 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel.
500 Intel 32-bit architecture (IA32), Linux-Libre kernel.
503 ARMv7-A architecture with hard float, Thumb-2 and NEON,
504 using the EABI hard-float application binary interface (ABI),
505 and Linux-Libre kernel.
508 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel.
511 @uref{https://hurd.gnu.org, GNU/Hurd} on the Intel 32-bit architecture
514 This configuration is experimental and under development. The easiest
515 way for you to give it a try is by setting up an instance of
516 @code{hurd-vm-service-type} on your GNU/Linux machine
517 (@pxref{transparent-emulation-qemu, @code{hurd-vm-service-type}}).
518 @xref{Contributing}, on how to help!
520 @item mips64el-linux (deprecated)
521 little-endian 64-bit MIPS processors, specifically the Loongson series,
522 n32 ABI, and Linux-Libre kernel. This configuration is no longer fully
523 supported; in particular, there is no ongoing work to ensure that this
524 architecture still works. Should someone decide they wish to revive this
525 architecture then the code is still available.
527 @item powerpc64le-linux
528 little-endian 64-bit Power ISA processors, Linux-Libre kernel. This
529 includes POWER9 systems such as the
530 @uref{https://www.fsf.org/news/talos-ii-mainboard-and-talos-ii-lite-mainboard-now-fsf-certified-to-respect-your-freedom,
531 RYF Talos II mainboard}. This platform is available as a "technology
532 preview": although it is supported, substitutes are not yet available
533 from the build farm (@pxref{Substitutes}), and some packages may fail to
534 build (@pxref{Tracking Bugs and Patches}). That said, the Guix
535 community is actively working on improving this support, and now is a
536 great time to try it and get involved!
540 With Guix@tie{}System, you @emph{declare} all aspects of the operating system
541 configuration and Guix takes care of instantiating the configuration in a
542 transactional, reproducible, and stateless fashion (@pxref{System
543 Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
544 initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
545 Manual}), the well-known GNU utilities and tool chain, as well as the
546 graphical environment or system services of your choice.
548 Guix System is available on all the above platforms except
549 @code{mips64el-linux} and @code{powerpc64le-linux}.
552 For information on porting to other architectures or kernels,
555 Building this distribution is a cooperative effort, and you are invited
556 to join! @xref{Contributing}, for information about how you can help.
559 @c *********************************************************************
561 @chapter Installation
563 @cindex installing Guix
566 We recommend the use of this
567 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
568 shell installer script} to install Guix on top of a running GNU/Linux system,
569 thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
570 with the installation of the package manager, which can be done on top of a
571 running GNU/Linux system. If, instead, you want to install the complete GNU
572 operating system, @pxref{System Installation}.} The script automates the
573 download, installation, and initial configuration of Guix. It should be run
577 @cindex foreign distro
578 @cindex directories related to foreign distro
579 When installed on a foreign distro, GNU@tie{}Guix complements the available
580 tools without interference. Its data lives exclusively in two directories,
581 usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
582 such as @file{/etc}, are left untouched.
584 Once installed, Guix can be updated by running @command{guix pull}
585 (@pxref{Invoking guix pull}).
587 If you prefer to perform the installation steps manually or want to tweak
588 them, you may find the following subsections useful. They describe the
589 software requirements of Guix, as well as how to install it manually and get
593 * Binary Installation:: Getting Guix running in no time!
594 * Requirements:: Software needed to build and run Guix.
595 * Running the Test Suite:: Testing Guix.
596 * Setting Up the Daemon:: Preparing the build daemon's environment.
597 * Invoking guix-daemon:: Running the build daemon.
598 * Application Setup:: Application-specific setup.
599 * Upgrading Guix:: Upgrading Guix and its build daemon.
602 @node Binary Installation
603 @section Binary Installation
605 @cindex installing Guix from binaries
606 @cindex installer script
607 This section describes how to install Guix on an arbitrary system from a
608 self-contained tarball providing binaries for Guix and for all its
609 dependencies. This is often quicker than installing from source, which
610 is described in the next sections. The only requirement is to have
613 @c Note duplicated from the ``Installation'' node.
615 We recommend the use of this
616 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
617 shell installer script}. The script automates the download, installation, and
618 initial configuration steps described below. It should be run as the root
619 user. As root, you can thus run this:
623 wget https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh
624 chmod +x guix-install.sh
628 When you're done, @pxref{Application Setup} for extra configuration you
629 might need, and @ref{Getting Started} for your first steps!
632 Installing goes along these lines:
636 @cindex downloading Guix binary
637 Download the binary tarball from
638 @indicateurl{@value{BASE-URL}/guix-binary-@value{VERSION}.x86_64-linux.tar.xz},
639 where @code{x86_64-linux} can be replaced with @code{i686-linux} for an
640 @code{i686} (32-bits) machine already running the kernel Linux, and so on
641 (@pxref{GNU Distribution}).
643 @c The following is somewhat duplicated in ``System Installation''.
644 Make sure to download the associated @file{.sig} file and to verify the
645 authenticity of the tarball against it, along these lines:
648 $ wget @value{BASE-URL}/guix-binary-@value{VERSION}.x86_64-linux.tar.xz.sig
649 $ gpg --verify guix-binary-@value{VERSION}.x86_64-linux.tar.xz.sig
652 If that command fails because you do not have the required public key,
653 then run this command to import it:
656 $ wget '@value{OPENPGP-SIGNING-KEY-URL}' \
657 -qO - | gpg --import -
661 and rerun the @code{gpg --verify} command.
663 Take note that a warning like ``This key is not certified with a trusted
664 signature!'' is normal.
666 @c end authentication part
669 Now, you need to become the @code{root} user. Depending on your distribution,
670 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
674 # tar --warning=no-timestamp -xf \
675 /path/to/guix-binary-@value{VERSION}.x86_64-linux.tar.xz
676 # mv var/guix /var/ && mv gnu /
679 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
680 The latter contains a ready-to-use profile for @code{root} (see next
683 Do @emph{not} unpack the tarball on a working Guix system since that
684 would overwrite its own essential files.
686 The @option{--warning=no-timestamp} option makes sure GNU@tie{}tar does
687 not emit warnings about ``implausibly old time stamps'' (such
688 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
690 They stem from the fact that all the
691 files in the archive have their modification time set to 1 (which
692 means January 1st, 1970). This is done on purpose to make sure the
693 archive content is independent of its creation time, thus making it
697 Make the profile available under @file{~root/.config/guix/current}, which is
698 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
701 # mkdir -p ~root/.config/guix
702 # ln -sf /var/guix/profiles/per-user/root/current-guix \
703 ~root/.config/guix/current
706 Source @file{etc/profile} to augment @env{PATH} and other relevant
707 environment variables:
710 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
711 source $GUIX_PROFILE/etc/profile
715 Create the group and user accounts for build users as explained below
716 (@pxref{Build Environment Setup}).
719 Run the daemon, and set it to automatically start on boot.
721 If your host distro uses the systemd init system, this can be achieved
724 @c Versions of systemd that supported symlinked service files are not
725 @c yet widely deployed, so we should suggest that users copy the service
728 @c See this thread for more information:
729 @c https://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
732 # cp ~root/.config/guix/current/lib/systemd/system/gnu-store.mount \
733 ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
735 # systemctl enable --now gnu-store.mount guix-daemon
738 If your host distro uses the Upstart init system:
741 # initctl reload-configuration
742 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
747 Otherwise, you can still start the daemon manually with:
750 # ~root/.config/guix/current/bin/guix-daemon \
751 --build-users-group=guixbuild
755 Make the @command{guix} command available to other users on the machine,
759 # mkdir -p /usr/local/bin
761 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
764 It is also a good idea to make the Info version of this manual available
768 # mkdir -p /usr/local/share/info
769 # cd /usr/local/share/info
770 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
774 That way, assuming @file{/usr/local/share/info} is in the search path,
775 running @command{info guix} will open this manual (@pxref{Other Info
776 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
780 @cindex substitutes, authorization thereof
781 To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
782 (@pxref{Substitutes}), authorize them:
785 # guix archive --authorize < \
786 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
790 Each user may need to perform a few additional steps to make their Guix
791 environment ready for use, @pxref{Application Setup}.
794 Voilà, the installation is complete!
796 You can confirm that Guix is working by installing a sample package into
803 The binary installation tarball can be (re)produced and verified simply
804 by running the following command in the Guix source tree:
807 make guix-binary.@var{system}.tar.xz
811 ...@: which, in turn, runs:
814 guix pack -s @var{system} --localstatedir \
815 --profile-name=current-guix guix
818 @xref{Invoking guix pack}, for more info on this handy tool.
821 @section Requirements
823 This section lists requirements when building Guix from source. The
824 build procedure for Guix is the same as for other GNU software, and is
825 not covered here. Please see the files @file{README} and @file{INSTALL}
826 in the Guix source tree for additional details.
828 @cindex official website
829 GNU Guix is available for download from its website at
830 @url{https://www.gnu.org/software/guix/}.
832 GNU Guix depends on the following packages:
835 @item @url{https://gnu.org/software/guile/, GNU Guile}, version 3.0.x or
837 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
840 @uref{https://gnutls.org/, GnuTLS}, specifically its Guile bindings
841 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
842 Guile,, gnutls-guile, GnuTLS-Guile});
844 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
846 @item @uref{https://notabug.org/guile-zlib/guile-zlib, Guile-zlib},
847 version 0.1.0 or later;
848 @item @uref{https://notabug.org/guile-lzlib/guile-lzlib, Guile-lzlib};
849 @item @uref{https://www.nongnu.org/guile-avahi/, Guile-Avahi};
851 @c FIXME: We need the #:fetch-options parameter of 'submodule-update',
852 @c which appeared in 0.5.0. Change below after string freeze.
853 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, version 0.3.0
855 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON}
857 @item @url{https://www.gnu.org/software/make/, GNU Make}.
860 The following dependencies are optional:
864 @c Note: We need at least 0.13.0 for #:nodelay.
865 Support for build offloading (@pxref{Daemon Offload Setup}) and
866 @command{guix copy} (@pxref{Invoking guix copy}) depends on
867 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
868 version 0.13.0 or later.
871 @uref{https://notabug.org/guile-zstd/guile-zstd, Guile-zstd}, for zstd
872 compression and decompression in @command{guix publish} and for
873 substitutes (@pxref{Invoking guix publish}).
876 @uref{https://ngyro.com/software/guile-semver.html, Guile-Semver} for
877 the @code{crate} importer (@pxref{Invoking guix import}).
880 @uref{https://www.nongnu.org/guile-lib/doc/ref/htmlprag/, Guile-Lib} for
881 the @code{go} importer (@pxref{Invoking guix import}) and for some of
882 the ``updaters'' (@pxref{Invoking guix refresh}).
885 When @url{http://www.bzip.org, libbz2} is available,
886 @command{guix-daemon} can use it to compress build logs.
889 Unless @option{--disable-daemon} was passed to @command{configure}, the
890 following packages are also needed:
893 @item @url{https://gnupg.org/, GNU libgcrypt};
894 @item @url{https://sqlite.org, SQLite 3};
895 @item @url{https://gcc.gnu.org, GCC's g++}, with support for the
899 @cindex state directory
900 When configuring Guix on a system that already has a Guix installation,
901 be sure to specify the same state directory as the existing installation
902 using the @option{--localstatedir} option of the @command{configure}
903 script (@pxref{Directory Variables, @code{localstatedir},, standards,
904 GNU Coding Standards}). Usually, this @var{localstatedir} option is
905 set to the value @file{/var}. The @command{configure} script protects
906 against unintended misconfiguration of @var{localstatedir} so you do not
907 inadvertently corrupt your store (@pxref{The Store}).
909 @node Running the Test Suite
910 @section Running the Test Suite
913 After a successful @command{configure} and @code{make} run, it is a good
914 idea to run the test suite. It can help catch issues with the setup or
915 environment, or bugs in Guix itself---and really, reporting test
916 failures is a good way to help improve the software. To run the test
923 Test cases can run in parallel: you can use the @code{-j} option of
924 GNU@tie{}make to speed things up. The first run may take a few minutes
925 on a recent machine; subsequent runs will be faster because the store
926 that is created for test purposes will already have various things in
929 It is also possible to run a subset of the tests by defining the
930 @code{TESTS} makefile variable as in this example:
933 make check TESTS="tests/store.scm tests/cpio.scm"
936 By default, tests results are displayed at a file level. In order to
937 see the details of every individual test cases, it is possible to define
938 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
941 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
944 The underlying SRFI 64 custom Automake test driver used for the 'check'
945 test suite (located at @file{build-aux/test-driver.scm}) also allows
946 selecting which test cases to run at a finer level, via its
947 @option{--select} and @option{--exclude} options. Here's an example, to
948 run all the test cases from the @file{tests/packages.scm} test file
949 whose names start with ``transaction-upgrade-entry'':
952 export SCM_LOG_DRIVER_FLAGS="--select=^transaction-upgrade-entry"
953 make check TESTS="tests/packages.scm"
956 Those wishing to inspect the results of failed tests directly from the
957 command line can add the @option{--errors-only=yes} option to the
958 @code{SCM_LOG_DRIVER_FLAGS} makefile variable and set the @code{VERBOSE}
959 Automake makefile variable, as in:
962 make check SCM_LOG_DRIVER_FLAGS="--brief=no --errors-only=yes" VERBOSE=1
965 The @option{--show-duration=yes} option can be used to print the
966 duration of the individual test cases, when used in combination with
970 make check SCM_LOG_DRIVER_FLAGS="--brief=no --show-duration=yes"
973 @xref{Parallel Test Harness,,,automake,GNU Automake} for more
974 information about the Automake Parallel Test Harness.
976 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
977 @file{test-suite.log} file. Please specify the Guix version being used
978 as well as version numbers of the dependencies (@pxref{Requirements}) in
981 Guix also comes with a whole-system test suite that tests complete
982 Guix System instances. It can only run on systems where
983 Guix is already installed, using:
990 or, again, by defining @code{TESTS} to select a subset of tests to run:
993 make check-system TESTS="basic mcron"
996 These system tests are defined in the @code{(gnu tests @dots{})}
997 modules. They work by running the operating systems under test with
998 lightweight instrumentation in a virtual machine (VM). They can be
999 computationally intensive or rather cheap, depending on whether
1000 substitutes are available for their dependencies (@pxref{Substitutes}).
1001 Some of them require a lot of storage space to hold VM images.
1003 Again in case of test failures, please send @email{bug-guix@@gnu.org}
1006 @node Setting Up the Daemon
1007 @section Setting Up the Daemon
1010 Operations such as building a package or running the garbage collector
1011 are all performed by a specialized process, the @dfn{build daemon}, on
1012 behalf of clients. Only the daemon may access the store and its
1013 associated database. Thus, any operation that manipulates the store
1014 goes through the daemon. For instance, command-line tools such as
1015 @command{guix package} and @command{guix build} communicate with the
1016 daemon (@i{via} remote procedure calls) to instruct it what to do.
1018 The following sections explain how to prepare the build daemon's
1019 environment. See also @ref{Substitutes}, for information on how to allow
1020 the daemon to download pre-built binaries.
1023 * Build Environment Setup:: Preparing the isolated build environment.
1024 * Daemon Offload Setup:: Offloading builds to remote machines.
1025 * SELinux Support:: Using an SELinux policy for the daemon.
1028 @node Build Environment Setup
1029 @subsection Build Environment Setup
1031 @cindex build environment
1032 In a standard multi-user setup, Guix and its daemon---the
1033 @command{guix-daemon} program---are installed by the system
1034 administrator; @file{/gnu/store} is owned by @code{root} and
1035 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
1036 Guix tools to build packages or otherwise access the store, and the
1037 daemon will do it on their behalf, ensuring that the store is kept in a
1038 consistent state, and allowing built packages to be shared among users.
1041 When @command{guix-daemon} runs as @code{root}, you may not want package
1042 build processes themselves to run as @code{root} too, for obvious
1043 security reasons. To avoid that, a special pool of @dfn{build users}
1044 should be created for use by build processes started by the daemon.
1045 These build users need not have a shell and a home directory: they will
1046 just be used when the daemon drops @code{root} privileges in build
1047 processes. Having several such users allows the daemon to launch
1048 distinct build processes under separate UIDs, which guarantees that they
1049 do not interfere with each other---an essential feature since builds are
1050 regarded as pure functions (@pxref{Introduction}).
1052 On a GNU/Linux system, a build user pool may be created like this (using
1053 Bash syntax and the @code{shadow} commands):
1055 @c See https://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
1056 @c for why `-G' is needed.
1058 # groupadd --system guixbuild
1059 # for i in $(seq -w 1 10);
1061 useradd -g guixbuild -G guixbuild \
1062 -d /var/empty -s $(which nologin) \
1063 -c "Guix build user $i" --system \
1069 The number of build users determines how many build jobs may run in
1070 parallel, as specified by the @option{--max-jobs} option
1071 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
1072 @command{guix system vm} and related commands, you may need to add the
1073 build users to the @code{kvm} group so they can access @file{/dev/kvm},
1074 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
1075 (@pxref{Invoking guix system}).
1077 The @code{guix-daemon} program may then be run as @code{root} with the
1078 following command@footnote{If your machine uses the systemd init system,
1079 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
1080 file in @file{/etc/systemd/system} will ensure that
1081 @command{guix-daemon} is automatically started. Similarly, if your
1082 machine uses the Upstart init system, drop the
1083 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
1084 file in @file{/etc/init}.}:
1087 # guix-daemon --build-users-group=guixbuild
1092 This way, the daemon starts build processes in a chroot, under one of
1093 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
1094 environment contains nothing but:
1096 @c Keep this list in sync with libstore/build.cc! -----------------------
1099 a minimal @code{/dev} directory, created mostly independently from the
1100 host @code{/dev}@footnote{``Mostly'', because while the set of files
1101 that appear in the chroot's @code{/dev} is fixed, most of these files
1102 can only be created if the host has them.};
1105 the @code{/proc} directory; it only shows the processes of the container
1106 since a separate PID name space is used;
1109 @file{/etc/passwd} with an entry for the current user and an entry for
1113 @file{/etc/group} with an entry for the user's group;
1116 @file{/etc/hosts} with an entry that maps @code{localhost} to
1120 a writable @file{/tmp} directory.
1123 You can influence the directory where the daemon stores build trees
1124 @i{via} the @env{TMPDIR} environment variable. However, the build tree
1125 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
1126 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
1127 This way, the value of @env{TMPDIR} does not leak inside build
1128 environments, which avoids discrepancies in cases where build processes
1129 capture the name of their build tree.
1133 The daemon also honors the @env{http_proxy} and @env{https_proxy}
1134 environment variables for HTTP and HTTPS downloads it performs, be it
1135 for fixed-output derivations (@pxref{Derivations}) or for substitutes
1136 (@pxref{Substitutes}).
1138 If you are installing Guix as an unprivileged user, it is still possible
1139 to run @command{guix-daemon} provided you pass @option{--disable-chroot}.
1140 However, build processes will not be isolated from one another, and not
1141 from the rest of the system. Thus, build processes may interfere with
1142 each other, and may access programs, libraries, and other files
1143 available on the system---making it much harder to view them as
1144 @emph{pure} functions.
1147 @node Daemon Offload Setup
1148 @subsection Using the Offload Facility
1152 When desired, the build daemon can @dfn{offload} derivation builds to
1153 other machines running Guix, using the @code{offload} @dfn{build
1154 hook}@footnote{This feature is available only when
1155 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1156 present.}. When that feature is enabled, a list of user-specified build
1157 machines is read from @file{/etc/guix/machines.scm}; every time a build
1158 is requested, for instance via @code{guix build}, the daemon attempts to
1159 offload it to one of the machines that satisfy the constraints of the
1160 derivation, in particular its system types---e.g., @code{x86_64-linux}.
1161 A single machine can have multiple system types, either because its
1162 architecture natively supports it, via emulation
1163 (@pxref{transparent-emulation-qemu, Transparent Emulation with QEMU}),
1164 or both. Missing prerequisites for the build are
1165 copied over SSH to the target machine, which then proceeds with the
1166 build; upon success the output(s) of the build are copied back to the
1167 initial machine. The offload facility comes with a basic scheduler that
1168 attempts to select the best machine. The best machine is chosen among
1169 the available machines based on criteria such as:
1173 The availability of a build slot. A build machine can have as many
1174 build slots (connections) as the value of the @code{parallel-builds}
1175 field of its @code{build-machine} object.
1178 Its relative speed, as defined via the @code{speed} field of its
1179 @code{build-machine} object.
1182 Its load. The normalized machine load must be lower than a threshold
1183 value, configurable via the @code{overload-threshold} field of its
1184 @code{build-machine} object.
1187 Disk space availability. More than a 100 MiB must be available.
1190 The @file{/etc/guix/machines.scm} file typically looks like this:
1193 (list (build-machine
1194 (name "eightysix.example.org")
1195 (systems (list "x86_64-linux" "i686-linux"))
1196 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1198 (speed 2.)) ;incredibly fast!
1201 (name "armeight.example.org")
1202 (systems (list "aarch64-linux"))
1203 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1206 (string-append (getenv "HOME")
1207 "/.ssh/identity-for-guix"))))
1211 In the example above we specify a list of two build machines, one for
1212 the @code{x86_64} and @code{i686} architectures and one for the
1213 @code{aarch64} architecture.
1215 In fact, this file is---not surprisingly!---a Scheme file that is
1216 evaluated when the @code{offload} hook is started. Its return value
1217 must be a list of @code{build-machine} objects. While this example
1218 shows a fixed list of build machines, one could imagine, say, using
1219 DNS-SD to return a list of potential build machines discovered in the
1220 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1221 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1224 @deftp {Data Type} build-machine
1225 This data type represents build machines to which the daemon may offload
1226 builds. The important fields are:
1231 The host name of the remote machine.
1234 The system types the remote machine supports---e.g., @code{(list
1235 "x86_64-linux" "i686-linux")}.
1238 The user account to use when connecting to the remote machine over SSH.
1239 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1240 allow non-interactive logins.
1243 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1244 This is used to authenticate the machine when we connect to it. It is a
1245 long string that looks like this:
1248 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1251 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1252 key can be found in a file such as
1253 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1255 If the machine is running the SSH daemon of GNU@tie{}lsh,
1256 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1257 similar file. It can be converted to the OpenSSH format using
1258 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1261 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1262 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1267 A number of optional fields may be specified:
1271 @item @code{port} (default: @code{22})
1272 Port number of SSH server on the machine.
1274 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1275 The SSH private key file to use when connecting to the machine, in
1276 OpenSSH format. This key must not be protected with a passphrase.
1278 Note that the default value is the private key @emph{of the root
1279 account}. Make sure it exists if you use the default.
1281 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1282 @itemx @code{compression-level} (default: @code{3})
1283 The SSH-level compression methods and compression level requested.
1285 Note that offloading relies on SSH compression to reduce bandwidth usage
1286 when transferring files to and from build machines.
1288 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1289 File name of the Unix-domain socket @command{guix-daemon} is listening
1292 @item @code{overload-threshold} (default: @code{0.6})
1293 The load threshold above which a potential offload machine is
1294 disregarded by the offload scheduler. The value roughly translates to
1295 the total processor usage of the build machine, ranging from 0.0 (0%) to
1296 1.0 (100%). It can also be disabled by setting
1297 @code{overload-threshold} to @code{#f}.
1299 @item @code{parallel-builds} (default: @code{1})
1300 The number of builds that may run in parallel on the machine.
1302 @item @code{speed} (default: @code{1.0})
1303 A ``relative speed factor''. The offload scheduler will tend to prefer
1304 machines with a higher speed factor.
1306 @item @code{features} (default: @code{'()})
1307 A list of strings denoting specific features supported by the machine.
1308 An example is @code{"kvm"} for machines that have the KVM Linux modules
1309 and corresponding hardware support. Derivations can request features by
1310 name, and they will be scheduled on matching build machines.
1315 The @command{guix} command must be in the search path on the build
1316 machines. You can check whether this is the case by running:
1319 ssh build-machine guix repl --version
1322 There is one last thing to do once @file{machines.scm} is in place. As
1323 explained above, when offloading, files are transferred back and forth
1324 between the machine stores. For this to work, you first need to
1325 generate a key pair on each machine to allow the daemon to export signed
1326 archives of files from the store (@pxref{Invoking guix archive}):
1329 # guix archive --generate-key
1333 Each build machine must authorize the key of the master machine so that
1334 it accepts store items it receives from the master:
1337 # guix archive --authorize < master-public-key.txt
1341 Likewise, the master machine must authorize the key of each build machine.
1343 All the fuss with keys is here to express pairwise mutual trust
1344 relations between the master and the build machines. Concretely, when
1345 the master receives files from a build machine (and @i{vice versa}), its
1346 build daemon can make sure they are genuine, have not been tampered
1347 with, and that they are signed by an authorized key.
1349 @cindex offload test
1350 To test whether your setup is operational, run this command on the
1357 This will attempt to connect to each of the build machines specified in
1358 @file{/etc/guix/machines.scm}, make sure Guix is
1359 available on each machine, attempt to export to the machine and import
1360 from it, and report any error in the process.
1362 If you want to test a different machine file, just specify it on the
1366 # guix offload test machines-qualif.scm
1369 Last, you can test the subset of the machines whose name matches a
1370 regular expression like this:
1373 # guix offload test machines.scm '\.gnu\.org$'
1376 @cindex offload status
1377 To display the current load of all build hosts, run this command on the
1381 # guix offload status
1385 @node SELinux Support
1386 @subsection SELinux Support
1388 @cindex SELinux, daemon policy
1389 @cindex mandatory access control, SELinux
1390 @cindex security, guix-daemon
1391 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1392 can be installed on a system where SELinux is enabled, in order to label
1393 Guix files and to specify the expected behavior of the daemon. Since
1394 Guix System does not provide an SELinux base policy, the daemon policy cannot
1395 be used on Guix System.
1397 @subsubsection Installing the SELinux policy
1398 @cindex SELinux, policy installation
1399 To install the policy run this command as root:
1402 semodule -i etc/guix-daemon.cil
1405 Then relabel the file system with @code{restorecon} or by a different
1406 mechanism provided by your system.
1408 Once the policy is installed, the file system has been relabeled, and
1409 the daemon has been restarted, it should be running in the
1410 @code{guix_daemon_t} context. You can confirm this with the following
1414 ps -Zax | grep guix-daemon
1417 Monitor the SELinux log files as you run a command like @code{guix build
1418 hello} to convince yourself that SELinux permits all necessary
1421 @subsubsection Limitations
1422 @cindex SELinux, limitations
1424 This policy is not perfect. Here is a list of limitations or quirks
1425 that should be considered when deploying the provided SELinux policy for
1430 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1431 operations involve contexts that have anything to do with
1432 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1433 but it would be preferable to define socket rules for only this label.
1436 @code{guix gc} cannot access arbitrary links to profiles. By design,
1437 the file label of the destination of a symlink is independent of the
1438 file label of the link itself. Although all profiles under
1439 $localstatedir are labelled, the links to these profiles inherit the
1440 label of the directory they are in. For links in the user’s home
1441 directory this will be @code{user_home_t}. But for links from the root
1442 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1443 directory, etc, this won’t work. @code{guix gc} would be prevented from
1444 reading and following these links.
1447 The daemon’s feature to listen for TCP connections might no longer work.
1448 This might require extra rules, because SELinux treats network sockets
1449 differently from files.
1452 Currently all files with a name matching the regular expression
1453 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1454 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1455 that name in any profile would be permitted to run in the
1456 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1457 build a package that provides this executable and convince a user to
1458 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1459 At that point SELinux could not prevent it from accessing files that are
1460 allowed for processes in that domain.
1462 You will need to relabel the store directory after all upgrades to
1463 @file{guix-daemon}, such as after running @code{guix pull}. Assuming the
1464 store is in @file{/gnu}, you can do this with @code{restorecon -vR /gnu},
1465 or by other means provided by your operating system.
1467 We could generate a much more restrictive policy at installation time,
1468 so that only the @emph{exact} file name of the currently installed
1469 @code{guix-daemon} executable would be labelled with
1470 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1471 The downside is that root would have to install or upgrade the policy at
1472 installation time whenever the Guix package that provides the
1473 effectively running @code{guix-daemon} executable is upgraded.
1476 @node Invoking guix-daemon
1477 @section Invoking @command{guix-daemon}
1479 The @command{guix-daemon} program implements all the functionality to
1480 access the store. This includes launching build processes, running the
1481 garbage collector, querying the availability of a build result, etc. It
1482 is normally run as @code{root} like this:
1485 # guix-daemon --build-users-group=guixbuild
1489 For details on how to set it up, @pxref{Setting Up the Daemon}.
1492 @cindex container, build environment
1493 @cindex build environment
1494 @cindex reproducible builds
1495 By default, @command{guix-daemon} launches build processes under
1496 different UIDs, taken from the build group specified with
1497 @option{--build-users-group}. In addition, each build process is run in a
1498 chroot environment that only contains the subset of the store that the
1499 build process depends on, as specified by its derivation
1500 (@pxref{Programming Interface, derivation}), plus a set of specific
1501 system directories. By default, the latter contains @file{/dev} and
1502 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1503 @dfn{container}: in addition to having its own file system tree, it has
1504 a separate mount name space, its own PID name space, network name space,
1505 etc. This helps achieve reproducible builds (@pxref{Features}).
1507 When the daemon performs a build on behalf of the user, it creates a
1508 build directory under @file{/tmp} or under the directory specified by
1509 its @env{TMPDIR} environment variable. This directory is shared with
1510 the container for the duration of the build, though within the container,
1511 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1513 The build directory is automatically deleted upon completion, unless the
1514 build failed and the client specified @option{--keep-failed}
1515 (@pxref{Common Build Options, @option{--keep-failed}}).
1517 The daemon listens for connections and spawns one sub-process for each session
1518 started by a client (one of the @command{guix} sub-commands). The
1519 @command{guix processes} command allows you to get an overview of the activity
1520 on your system by viewing each of the active sessions and clients.
1521 @xref{Invoking guix processes}, for more information.
1523 The following command-line options are supported:
1526 @item --build-users-group=@var{group}
1527 Take users from @var{group} to run build processes (@pxref{Setting Up
1528 the Daemon, build users}).
1530 @item --no-substitutes
1532 Do not use substitutes for build products. That is, always build things
1533 locally instead of allowing downloads of pre-built binaries
1534 (@pxref{Substitutes}).
1536 When the daemon runs with @option{--no-substitutes}, clients can still
1537 explicitly enable substitution @i{via} the @code{set-build-options}
1538 remote procedure call (@pxref{The Store}).
1540 @anchor{daemon-substitute-urls}
1541 @item --substitute-urls=@var{urls}
1542 Consider @var{urls} the default whitespace-separated list of substitute
1543 source URLs. When this option is omitted,
1544 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1546 This means that substitutes may be downloaded from @var{urls}, as long
1547 as they are signed by a trusted signature (@pxref{Substitutes}).
1549 @xref{Getting Substitutes from Other Servers}, for more information on
1550 how to configure the daemon to get substitutes from other servers.
1554 Do not use offload builds to other machines (@pxref{Daemon Offload
1555 Setup}). That is, always build things locally instead of offloading
1556 builds to remote machines.
1558 @item --cache-failures
1559 Cache build failures. By default, only successful builds are cached.
1561 When this option is used, @command{guix gc --list-failures} can be used
1562 to query the set of store items marked as failed; @command{guix gc
1563 --clear-failures} removes store items from the set of cached failures.
1564 @xref{Invoking guix gc}.
1566 @item --cores=@var{n}
1568 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1571 The default value is @code{0}, but it may be overridden by clients, such
1572 as the @option{--cores} option of @command{guix build} (@pxref{Invoking
1575 The effect is to define the @env{NIX_BUILD_CORES} environment variable
1576 in the build process, which can then use it to exploit internal
1577 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1579 @item --max-jobs=@var{n}
1581 Allow at most @var{n} build jobs in parallel. The default value is
1582 @code{1}. Setting it to @code{0} means that no builds will be performed
1583 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1584 Setup}), or simply fail.
1586 @item --max-silent-time=@var{seconds}
1587 When the build or substitution process remains silent for more than
1588 @var{seconds}, terminate it and report a build failure.
1590 The default value is @code{0}, which disables the timeout.
1592 The value specified here can be overridden by clients (@pxref{Common
1593 Build Options, @option{--max-silent-time}}).
1595 @item --timeout=@var{seconds}
1596 Likewise, when the build or substitution process lasts for more than
1597 @var{seconds}, terminate it and report a build failure.
1599 The default value is @code{0}, which disables the timeout.
1601 The value specified here can be overridden by clients (@pxref{Common
1602 Build Options, @option{--timeout}}).
1604 @item --rounds=@var{N}
1605 Build each derivation @var{n} times in a row, and raise an error if
1606 consecutive build results are not bit-for-bit identical. Note that this
1607 setting can be overridden by clients such as @command{guix build}
1608 (@pxref{Invoking guix build}).
1610 When used in conjunction with @option{--keep-failed}, the differing
1611 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1612 This makes it easy to look for differences between the two results.
1615 Produce debugging output.
1617 This is useful to debug daemon start-up issues, but then it may be
1618 overridden by clients, for example the @option{--verbosity} option of
1619 @command{guix build} (@pxref{Invoking guix build}).
1621 @item --chroot-directory=@var{dir}
1622 Add @var{dir} to the build chroot.
1624 Doing this may change the result of build processes---for instance if
1625 they use optional dependencies found in @var{dir} when it is available,
1626 and not otherwise. For that reason, it is not recommended to do so.
1627 Instead, make sure that each derivation declares all the inputs that it
1630 @item --disable-chroot
1631 Disable chroot builds.
1633 Using this option is not recommended since, again, it would allow build
1634 processes to gain access to undeclared dependencies. It is necessary,
1635 though, when @command{guix-daemon} is running under an unprivileged user
1638 @item --log-compression=@var{type}
1639 Compress build logs according to @var{type}, one of @code{gzip},
1640 @code{bzip2}, or @code{none}.
1642 Unless @option{--lose-logs} is used, all the build logs are kept in the
1643 @var{localstatedir}. To save space, the daemon automatically compresses
1644 them with Bzip2 by default.
1646 @item --discover[=yes|no]
1647 Whether to discover substitute servers on the local network using mDNS
1650 This feature is still experimental. However, here are a few
1655 It might be faster/less expensive than fetching from remote servers;
1657 There are no security risks, only genuine substitutes will be used
1658 (@pxref{Substitute Authentication});
1660 An attacker advertising @command{guix publish} on your LAN cannot serve
1661 you malicious binaries, but they can learn what software you’re
1664 Servers may serve substitute over HTTP, unencrypted, so anyone on the
1665 LAN can see what software you’re installing.
1668 It is also possible to enable or disable substitute server discovery at
1669 run-time by running:
1672 herd discover guix-daemon on
1673 herd discover guix-daemon off
1676 @item --disable-deduplication
1677 @cindex deduplication
1678 Disable automatic file ``deduplication'' in the store.
1680 By default, files added to the store are automatically ``deduplicated'':
1681 if a newly added file is identical to another one found in the store,
1682 the daemon makes the new file a hard link to the other file. This can
1683 noticeably reduce disk usage, at the expense of slightly increased
1684 input/output load at the end of a build process. This option disables
1687 @item --gc-keep-outputs[=yes|no]
1688 Tell whether the garbage collector (GC) must keep outputs of live
1692 @cindex garbage collector roots
1693 When set to @code{yes}, the GC will keep the outputs of any live
1694 derivation available in the store---the @file{.drv} files. The default
1695 is @code{no}, meaning that derivation outputs are kept only if they are
1696 reachable from a GC root. @xref{Invoking guix gc}, for more on GC
1699 @item --gc-keep-derivations[=yes|no]
1700 Tell whether the garbage collector (GC) must keep derivations
1701 corresponding to live outputs.
1703 When set to @code{yes}, as is the case by default, the GC keeps
1704 derivations---i.e., @file{.drv} files---as long as at least one of their
1705 outputs is live. This allows users to keep track of the origins of
1706 items in their store. Setting it to @code{no} saves a bit of disk
1709 In this way, setting @option{--gc-keep-derivations} to @code{yes} causes
1710 liveness to flow from outputs to derivations, and setting
1711 @option{--gc-keep-outputs} to @code{yes} causes liveness to flow from
1712 derivations to outputs. When both are set to @code{yes}, the effect is
1713 to keep all the build prerequisites (the sources, compiler, libraries,
1714 and other build-time tools) of live objects in the store, regardless of
1715 whether these prerequisites are reachable from a GC root. This is
1716 convenient for developers since it saves rebuilds or downloads.
1718 @item --impersonate-linux-2.6
1719 On Linux-based systems, impersonate Linux 2.6. This means that the
1720 kernel's @command{uname} system call will report 2.6 as the release number.
1722 This might be helpful to build programs that (usually wrongfully) depend
1723 on the kernel version number.
1726 Do not keep build logs. By default they are kept under
1727 @file{@var{localstatedir}/guix/log}.
1729 @item --system=@var{system}
1730 Assume @var{system} as the current system type. By default it is the
1731 architecture/kernel pair found at configure time, such as
1732 @code{x86_64-linux}.
1734 @item --listen=@var{endpoint}
1735 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1736 as the file name of a Unix-domain socket if it starts with
1737 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1738 host name or host name and port to listen to. Here are a few examples:
1741 @item --listen=/gnu/var/daemon
1742 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1743 creating it if needed.
1745 @item --listen=localhost
1746 @cindex daemon, remote access
1747 @cindex remote access to the daemon
1748 @cindex daemon, cluster setup
1749 @cindex clusters, daemon setup
1750 Listen for TCP connections on the network interface corresponding to
1751 @code{localhost}, on port 44146.
1753 @item --listen=128.0.0.42:1234
1754 Listen for TCP connections on the network interface corresponding to
1755 @code{128.0.0.42}, on port 1234.
1758 This option can be repeated multiple times, in which case
1759 @command{guix-daemon} accepts connections on all the specified
1760 endpoints. Users can tell client commands what endpoint to connect to
1761 by setting the @env{GUIX_DAEMON_SOCKET} environment variable
1762 (@pxref{The Store, @env{GUIX_DAEMON_SOCKET}}).
1765 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1766 @option{--listen=@var{host}} is suitable on local networks, such as
1767 clusters, where only trusted nodes may connect to the build daemon. In
1768 other cases where remote access to the daemon is needed, we recommend
1769 using Unix-domain sockets along with SSH.
1772 When @option{--listen} is omitted, @command{guix-daemon} listens for
1773 connections on the Unix-domain socket located at
1774 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1778 @node Application Setup
1779 @section Application Setup
1781 @cindex foreign distro
1782 When using Guix on top of GNU/Linux distribution other than Guix System---a
1783 so-called @dfn{foreign distro}---a few additional steps are needed to
1784 get everything in place. Here are some of them.
1788 @anchor{locales-and-locpath}
1789 @cindex locales, when not on Guix System
1791 @vindex GUIX_LOCPATH
1792 Packages installed @i{via} Guix will not use the locale data of the
1793 host system. Instead, you must first install one of the locale packages
1794 available with Guix and then define the @env{GUIX_LOCPATH} environment
1798 $ guix install glibc-locales
1799 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1802 Note that the @code{glibc-locales} package contains data for all the
1803 locales supported by the GNU@tie{}libc and weighs in at around
1804 917@tie{}MiB@. Alternatively, the @code{glibc-utf8-locales} is smaller but
1805 limited to a few UTF-8 locales.
1807 The @env{GUIX_LOCPATH} variable plays a role similar to @env{LOCPATH}
1808 (@pxref{Locale Names, @env{LOCPATH},, libc, The GNU C Library Reference
1809 Manual}). There are two important differences though:
1813 @env{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1814 provided by foreign distros. Thus, using @env{GUIX_LOCPATH} allows you
1815 to make sure the programs of the foreign distro will not end up loading
1816 incompatible locale data.
1819 libc suffixes each entry of @env{GUIX_LOCPATH} with @code{/X.Y}, where
1820 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1821 should your Guix profile contain a mixture of programs linked against
1822 different libc version, each libc version will only try to load locale
1823 data in the right format.
1826 This is important because the locale data format used by different libc
1827 versions may be incompatible.
1829 @subsection Name Service Switch
1831 @cindex name service switch, glibc
1832 @cindex NSS (name service switch), glibc
1833 @cindex nscd (name service caching daemon)
1834 @cindex name service caching daemon (nscd)
1835 When using Guix on a foreign distro, we @emph{strongly recommend} that
1836 the system run the GNU C library's @dfn{name service cache daemon},
1837 @command{nscd}, which should be listening on the
1838 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1839 installed with Guix may fail to look up host names or user accounts, or
1840 may even crash. The next paragraphs explain why.
1842 @cindex @file{nsswitch.conf}
1843 The GNU C library implements a @dfn{name service switch} (NSS), which is
1844 an extensible mechanism for ``name lookups'' in general: host name
1845 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1846 The GNU C Library Reference Manual}).
1848 @cindex Network information service (NIS)
1849 @cindex NIS (Network information service)
1850 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1851 lookup implementations: for example, the @code{nss-mdns} plugin allow
1852 resolution of @code{.local} host names, the @code{nis} plugin allows
1853 user account lookup using the Network information service (NIS), and so
1854 on. These extra ``lookup services'' are configured system-wide in
1855 @file{/etc/nsswitch.conf}, and all the programs running on the system
1856 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1859 When they perform a name lookup---for instance by calling the
1860 @code{getaddrinfo} function in C---applications first try to connect to
1861 the nscd; on success, nscd performs name lookups on their behalf. If
1862 the nscd is not running, then they perform the name lookup by
1863 themselves, by loading the name lookup services into their own address
1864 space and running it. These name lookup services---the
1865 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1866 the host system's C library, rather than from the C library the
1867 application is linked against (the C library coming from Guix).
1869 And this is where the problem is: if your application is linked against
1870 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1871 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1872 likely crash or have its name lookups fail unexpectedly.
1874 Running @command{nscd} on the system, among other advantages, eliminates
1875 this binary incompatibility problem because those @code{libnss_*.so}
1876 files are loaded in the @command{nscd} process, not in applications
1879 @subsection X11 Fonts
1882 The majority of graphical applications use Fontconfig to locate and
1883 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1884 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1885 by default. Thus, to allow graphical applications installed with Guix
1886 to display fonts, you have to install fonts with Guix as well.
1887 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1888 @code{font-gnu-freefont}.
1890 @cindex @code{fc-cache}
1892 Once you have installed or removed fonts, or when you notice an
1893 application that does not find fonts, you may need to install Fontconfig
1894 and to force an update of its font cache by running:
1897 guix install fontconfig
1901 To display text written in Chinese languages, Japanese, or Korean in
1902 graphical applications, consider installing
1903 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1904 has multiple outputs, one per language family (@pxref{Packages with
1905 Multiple Outputs}). For instance, the following command installs fonts
1906 for Chinese languages:
1909 guix install font-adobe-source-han-sans:cn
1912 @cindex @code{xterm}
1913 Older programs such as @command{xterm} do not use Fontconfig and instead
1914 rely on server-side font rendering. Such programs require to specify a
1915 full name of a font using XLFD (X Logical Font Description), like this:
1918 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1921 To be able to use such full names for the TrueType fonts installed in
1922 your Guix profile, you need to extend the font path of the X server:
1924 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1925 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1927 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1930 @cindex @code{xlsfonts}
1931 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1932 to make sure your TrueType fonts are listed there.
1935 @subsection X.509 Certificates
1937 @cindex @code{nss-certs}
1938 The @code{nss-certs} package provides X.509 certificates, which allow
1939 programs to authenticate Web servers accessed over HTTPS.
1941 When using Guix on a foreign distro, you can install this package and
1942 define the relevant environment variables so that packages know where to
1943 look for certificates. @xref{X.509 Certificates}, for detailed
1946 @subsection Emacs Packages
1948 @cindex @code{emacs}
1949 When you install Emacs packages with Guix, the Elisp files are placed
1950 under the @file{share/emacs/site-lisp/} directory of the profile in
1951 which they are installed. The Elisp libraries are made available to
1952 Emacs through the @env{EMACSLOADPATH} environment variable, which is
1953 set when installing Emacs itself.
1955 Additionally, autoload definitions are automatically evaluated at the
1956 initialization of Emacs, by the Guix-specific
1957 @code{guix-emacs-autoload-packages} procedure. If, for some reason, you
1958 want to avoid auto-loading the Emacs packages installed with Guix, you
1959 can do so by running Emacs with the @option{--no-site-file} option
1960 (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1963 @node Upgrading Guix
1964 @section Upgrading Guix
1966 @cindex Upgrading Guix, on a foreign distro
1968 To upgrade Guix, run:
1974 @xref{Invoking guix pull}, for more information.
1976 @cindex upgrading Guix for the root user, on a foreign distro
1977 @cindex upgrading the Guix daemon, on a foreign distro
1978 @cindex @command{guix pull} for the root user, on a foreign distro
1980 On a foreign distro, you can upgrade the build daemon by running:
1987 followed by (assuming your distro uses the systemd service management
1991 systemctl restart guix-daemon.service
1994 On Guix System, upgrading the daemon is achieved by reconfiguring the
1995 system (@pxref{Invoking guix system, @code{guix system reconfigure}}).
1999 @c *********************************************************************
2000 @node System Installation
2001 @chapter System Installation
2003 @cindex installing Guix System
2004 @cindex Guix System, installation
2005 This section explains how to install Guix System
2006 on a machine. Guix, as a package manager, can
2007 also be installed on top of a running GNU/Linux system,
2008 @pxref{Installation}.
2012 @c This paragraph is for people reading this from tty2 of the
2013 @c installation image.
2014 You are reading this documentation with an Info reader. For details on
2015 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
2016 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
2017 Info}. Hit @kbd{l} afterwards to come back here.
2019 Alternatively, run @command{info info} in another tty to keep the manual
2025 * Limitations:: What you can expect.
2026 * Hardware Considerations:: Supported hardware.
2027 * USB Stick and DVD Installation:: Preparing the installation medium.
2028 * Preparing for Installation:: Networking, partitioning, etc.
2029 * Guided Graphical Installation:: Easy graphical installation.
2030 * Manual Installation:: Manual installation for wizards.
2031 * After System Installation:: When installation succeeded.
2032 * Installing Guix in a VM:: Guix System playground.
2033 * Building the Installation Image:: How this comes to be.
2037 @section Limitations
2039 We consider Guix System to be ready for a wide range of ``desktop'' and server
2040 use cases. The reliability guarantees it provides---transactional upgrades
2041 and rollbacks, reproducibility---make it a solid foundation.
2043 Nevertheless, before you proceed with the installation, be aware of the
2044 following noteworthy limitations applicable to version @value{VERSION}:
2048 More and more system services are provided (@pxref{Services}), but some
2052 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
2053 as well as a number of X11 window managers. However, KDE is currently
2057 More than a disclaimer, this is an invitation to report issues (and success
2058 stories!), and to join us in improving it. @xref{Contributing}, for more
2062 @node Hardware Considerations
2063 @section Hardware Considerations
2065 @cindex hardware support on Guix System
2066 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
2067 builds around the kernel Linux-libre, which means that only hardware for
2068 which free software drivers and firmware exist is supported. Nowadays,
2069 a wide range of off-the-shelf hardware is supported on
2070 GNU/Linux-libre---from keyboards to graphics cards to scanners and
2071 Ethernet controllers. Unfortunately, there are still areas where
2072 hardware vendors deny users control over their own computing, and such
2073 hardware is not supported on Guix System.
2075 @cindex WiFi, hardware support
2076 One of the main areas where free drivers or firmware are lacking is WiFi
2077 devices. WiFi devices known to work include those using Atheros chips
2078 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
2079 driver, and those using Broadcom/AirForce chips (BCM43xx with
2080 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
2081 Linux-libre driver. Free firmware exists for both and is available
2082 out-of-the-box on Guix System, as part of @code{%base-firmware}
2083 (@pxref{operating-system Reference, @code{firmware}}).
2085 @cindex RYF, Respects Your Freedom
2086 The @uref{https://www.fsf.org/, Free Software Foundation} runs
2087 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
2088 certification program for hardware products that respect your freedom
2089 and your privacy and ensure that you have control over your device. We
2090 encourage you to check the list of RYF-certified devices.
2092 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
2093 web site. It contains a catalog of hardware devices with information
2094 about their support in GNU/Linux.
2097 @node USB Stick and DVD Installation
2098 @section USB Stick and DVD Installation
2100 An ISO-9660 installation image that can be written to a USB stick or
2101 burnt to a DVD can be downloaded from
2102 @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso.xz},
2103 where you can replace @code{x86_64-linux} with one of:
2107 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
2110 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
2113 @c start duplication of authentication part from ``Binary Installation''
2114 Make sure to download the associated @file{.sig} file and to verify the
2115 authenticity of the image against it, along these lines:
2118 $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso.xz.sig
2119 $ gpg --verify guix-system-install-@value{VERSION}.x86_64-linux.iso.xz.sig
2122 If that command fails because you do not have the required public key,
2123 then run this command to import it:
2126 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
2127 -qO - | gpg --import -
2131 and rerun the @code{gpg --verify} command.
2133 Take note that a warning like ``This key is not certified with a trusted
2134 signature!'' is normal.
2138 This image contains the tools necessary for an installation.
2139 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
2141 @unnumberedsubsec Copying to a USB Stick
2143 To copy the image to a USB stick, follow these steps:
2147 Decompress the image using the @command{xz} command:
2150 xz -d guix-system-install-@value{VERSION}.x86_64-linux.iso.xz
2154 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
2155 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
2156 copy the image with:
2159 dd if=guix-system-install-@value{VERSION}.x86_64-linux.iso of=/dev/sdX status=progress
2163 Access to @file{/dev/sdX} usually requires root privileges.
2166 @unnumberedsubsec Burning on a DVD
2168 To copy the image to a DVD, follow these steps:
2172 Decompress the image using the @command{xz} command:
2175 xz -d guix-system-install-@value{VERSION}.x86_64-linux.iso.xz
2179 Insert a blank DVD into your machine, and determine
2180 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
2181 copy the image with:
2184 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.x86_64-linux.iso
2187 Access to @file{/dev/srX} usually requires root privileges.
2190 @unnumberedsubsec Booting
2192 Once this is done, you should be able to reboot the system and boot from
2193 the USB stick or DVD@. The latter usually requires you to get in the
2194 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
2195 In order to boot from Libreboot, switch to the command mode by pressing
2196 the @kbd{c} key and type @command{search_grub usb}.
2198 @xref{Installing Guix in a VM}, if, instead, you would like to install
2199 Guix System in a virtual machine (VM).
2202 @node Preparing for Installation
2203 @section Preparing for Installation
2205 Once you have booted, you can use the guided graphical installer, which makes
2206 it easy to get started (@pxref{Guided Graphical Installation}). Alternatively,
2207 if you are already familiar with GNU/Linux and if you want more control than
2208 what the graphical installer provides, you can choose the ``manual''
2209 installation process (@pxref{Manual Installation}).
2211 The graphical installer is available on TTY1. You can obtain root shells on
2212 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
2213 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
2214 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
2215 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
2216 which allows you to select text with the left mouse button and to paste it
2217 with the middle button.
2220 Installation requires access to the Internet so that any missing
2221 dependencies of your system configuration can be downloaded. See the
2222 ``Networking'' section below.
2225 @node Guided Graphical Installation
2226 @section Guided Graphical Installation
2228 The graphical installer is a text-based user interface. It will guide you,
2229 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
2231 The first dialog boxes allow you to set up the system as you use it during the
2232 installation: you can choose the language, keyboard layout, and set up
2233 networking, which will be used during the installation. The image below shows
2234 the networking dialog.
2236 @image{images/installer-network,5in,, networking setup with the graphical installer}
2238 Later steps allow you to partition your hard disk, as shown in the image
2239 below, to choose whether or not to use encrypted file systems, to enter the
2240 host name and root password, and to create an additional account, among other
2243 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2245 Note that, at any time, the installer allows you to exit the current
2246 installation step and resume at a previous step, as show in the image below.
2248 @image{images/installer-resume,5in,, resuming the installation process}
2250 Once you're done, the installer produces an operating system configuration and
2251 displays it (@pxref{Using the Configuration System}). At that point you can
2252 hit ``OK'' and installation will proceed. On success, you can reboot into the
2253 new system and enjoy. @xref{After System Installation}, for what's next!
2256 @node Manual Installation
2257 @section Manual Installation
2259 This section describes how you would ``manually'' install GNU@tie{}Guix System
2260 on your machine. This option requires familiarity with GNU/Linux, with the
2261 shell, and with common administration tools. If you think this is not for
2262 you, consider using the guided graphical installer (@pxref{Guided Graphical
2265 The installation system provides root shells on TTYs 3 to 6; press
2266 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2267 many common tools needed to install the system. But it is also a full-blown
2268 Guix System, which means that you can install additional packages, should you
2269 need it, using @command{guix package} (@pxref{Invoking guix package}).
2272 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2273 * Proceeding with the Installation:: Installing.
2276 @node Keyboard Layout and Networking and Partitioning
2277 @subsection Keyboard Layout, Networking, and Partitioning
2279 Before you can install the system, you may want to adjust the keyboard layout,
2280 set up networking, and partition your target hard disk. This section will
2281 guide you through this.
2283 @subsubsection Keyboard Layout
2285 @cindex keyboard layout
2286 The installation image uses the US qwerty keyboard layout. If you want
2287 to change it, you can use the @command{loadkeys} command. For example,
2288 the following command selects the Dvorak keyboard layout:
2294 See the files under @file{/run/current-system/profile/share/keymaps} for
2295 a list of available keyboard layouts. Run @command{man loadkeys} for
2298 @subsubsection Networking
2300 Run the following command to see what your network interfaces are called:
2307 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2313 @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2314 Wired interfaces have a name starting with @samp{e}; for example, the
2315 interface corresponding to the first on-board Ethernet controller is
2316 called @samp{eno1}. Wireless interfaces have a name starting with
2317 @samp{w}, like @samp{w1p2s0}.
2320 @item Wired connection
2321 To configure a wired network run the following command, substituting
2322 @var{interface} with the name of the wired interface you want to use.
2325 ifconfig @var{interface} up
2329 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2332 ip link set @var{interface} up
2335 @item Wireless connection
2338 To configure wireless networking, you can create a configuration file
2339 for the @command{wpa_supplicant} configuration tool (its location is not
2340 important) using one of the available text editors such as
2344 nano wpa_supplicant.conf
2347 As an example, the following stanza can go to this file and will work
2348 for many wireless networks, provided you give the actual SSID and
2349 passphrase for the network you are connecting to:
2353 ssid="@var{my-ssid}"
2355 psk="the network's secret passphrase"
2359 Start the wireless service and run it in the background with the
2360 following command (substitute @var{interface} with the name of the
2361 network interface you want to use):
2364 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2367 Run @command{man wpa_supplicant} for more information.
2371 At this point, you need to acquire an IP address. On a network where IP
2372 addresses are automatically assigned @i{via} DHCP, you can run:
2375 dhclient -v @var{interface}
2378 Try to ping a server to see if networking is up and running:
2384 Setting up network access is almost always a requirement because the
2385 image does not contain all the software and tools that may be needed.
2387 @cindex proxy, during system installation
2388 If you need HTTP and HTTPS access to go through a proxy, run the
2392 herd set-http-proxy guix-daemon @var{URL}
2396 where @var{URL} is the proxy URL, for example
2397 @code{http://example.org:8118}.
2399 @cindex installing over SSH
2400 If you want to, you can continue the installation remotely by starting
2404 herd start ssh-daemon
2407 Make sure to either set a password with @command{passwd}, or configure
2408 OpenSSH public key authentication before logging in.
2410 @subsubsection Disk Partitioning
2412 Unless this has already been done, the next step is to partition, and
2413 then format the target partition(s).
2415 The installation image includes several partitioning tools, including
2416 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2417 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2418 the partition layout you want:
2424 If your disk uses the GUID Partition Table (GPT) format and you plan to
2425 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2426 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2429 @cindex EFI, installation
2430 @cindex UEFI, installation
2431 @cindex ESP, EFI system partition
2432 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2433 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2434 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2437 parted /dev/sda set 1 esp on
2441 @vindex grub-bootloader
2442 @vindex grub-efi-bootloader
2443 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2444 @file{/sys/firmware/efi} exists in the installation image, then you should
2445 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2446 Otherwise you should use the BIOS-based GRUB, known as
2447 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2451 Once you are done partitioning the target hard disk drive, you have to
2452 create a file system on the relevant partition(s)@footnote{Currently
2453 Guix System only supports ext4, btrfs, JFS, and F2FS file systems. In
2454 particular, code that reads file system UUIDs and labels only works for these
2455 file system types.}. For the ESP, if you have one and assuming it is
2456 @file{/dev/sda1}, run:
2459 mkfs.fat -F32 /dev/sda1
2462 For the root file system, ext4 is the most widely used format. Other
2463 file systems, such as Btrfs, support compression, which is reported to
2464 nicely complement file deduplication that the daemon performs
2465 independently of the file system (@pxref{Invoking guix-daemon,
2468 Preferably, assign file systems a label so that you can easily and
2469 reliably refer to them in @code{file-system} declarations (@pxref{File
2470 Systems}). This is typically done using the @code{-L} option of
2471 @command{mkfs.ext4} and related commands. So, assuming the target root
2472 partition lives at @file{/dev/sda2}, a file system with the label
2473 @code{my-root} can be created with:
2476 mkfs.ext4 -L my-root /dev/sda2
2479 @cindex encrypted disk
2480 If you are instead planning to encrypt the root partition, you can use
2481 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2482 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2483 @code{man cryptsetup}} for more information). Assuming you want to
2484 store the root partition on @file{/dev/sda2}, the command sequence would
2485 be along these lines:
2488 cryptsetup luksFormat /dev/sda2
2489 cryptsetup open --type luks /dev/sda2 my-partition
2490 mkfs.ext4 -L my-root /dev/mapper/my-partition
2493 Once that is done, mount the target file system under @file{/mnt}
2494 with a command like (again, assuming @code{my-root} is the label of the
2498 mount LABEL=my-root /mnt
2501 Also mount any other file systems you would like to use on the target
2502 system relative to this path. If you have opted for @file{/boot/efi} as an
2503 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2504 found by @code{guix system init} afterwards.
2506 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2507 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2508 sure to initialize them with @command{mkswap}. Assuming you have one
2509 swap partition on @file{/dev/sda3}, you would run:
2516 Alternatively, you may use a swap file. For example, assuming that in
2517 the new system you want to use the file @file{/swapfile} as a swap file,
2518 you would run@footnote{This example will work for many types of file
2519 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2520 btrfs), the required steps may be different. For details, see the
2521 manual pages for @command{mkswap} and @command{swapon}.}:
2524 # This is 10 GiB of swap space. Adjust "count" to change the size.
2525 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2526 # For security, make the file readable and writable only by root.
2527 chmod 600 /mnt/swapfile
2528 mkswap /mnt/swapfile
2529 swapon /mnt/swapfile
2532 Note that if you have encrypted the root partition and created a swap
2533 file in its file system as described above, then the encryption also
2534 protects the swap file, just like any other file in that file system.
2536 @node Proceeding with the Installation
2537 @subsection Proceeding with the Installation
2539 With the target partitions ready and the target root mounted on
2540 @file{/mnt}, we're ready to go. First, run:
2543 herd start cow-store /mnt
2546 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2547 during the installation phase are written to the target disk on @file{/mnt}
2548 rather than kept in memory. This is necessary because the first phase of
2549 the @command{guix system init} command (see below) entails downloads or
2550 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2552 Next, you have to edit a file and
2553 provide the declaration of the operating system to be installed. To
2554 that end, the installation system comes with three text editors. We
2555 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2556 supports syntax highlighting and parentheses matching; other editors
2557 include GNU Zile (an Emacs clone), and
2558 nvi (a clone of the original BSD @command{vi} editor).
2559 We strongly recommend storing that file on the target root file system, say,
2560 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2561 configuration file once you have rebooted into the newly-installed system.
2563 @xref{Using the Configuration System}, for an overview of the
2564 configuration file. The example configurations discussed in that
2565 section are available under @file{/etc/configuration} in the
2566 installation image. Thus, to get started with a system configuration
2567 providing a graphical display server (a ``desktop'' system), you can run
2568 something along these lines:
2572 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2573 # nano /mnt/etc/config.scm
2576 You should pay attention to what your configuration file contains, and
2581 Make sure the @code{bootloader-configuration} form refers to the target
2582 you want to install GRUB on. It should mention @code{grub-bootloader} if
2583 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2584 for newer UEFI systems. For legacy systems, the @code{target} field
2585 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2586 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2587 currently mounted and a @code{file-system} entry is specified in your
2591 Be sure that your file system labels match the value of their respective
2592 @code{device} fields in your @code{file-system} configuration, assuming
2593 your @code{file-system} configuration uses the @code{file-system-label}
2594 procedure in its @code{device} field.
2597 If there are encrypted or RAID partitions, make sure to add a
2598 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2601 Once you are done preparing the configuration file, the new system must
2602 be initialized (remember that the target root file system is mounted
2606 guix system init /mnt/etc/config.scm /mnt
2610 This copies all the necessary files and installs GRUB on
2611 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2612 more information, @pxref{Invoking guix system}. This command may trigger
2613 downloads or builds of missing packages, which can take some time.
2615 Once that command has completed---and hopefully succeeded!---you can run
2616 @command{reboot} and boot into the new system. The @code{root} password
2617 in the new system is initially empty; other users' passwords need to be
2618 initialized by running the @command{passwd} command as @code{root},
2619 unless your configuration specifies otherwise
2620 (@pxref{user-account-password, user account passwords}).
2621 @xref{After System Installation}, for what's next!
2624 @node After System Installation
2625 @section After System Installation
2627 Success, you've now booted into Guix System! From then on, you can update the
2628 system whenever you want by running, say:
2632 sudo guix system reconfigure /etc/config.scm
2636 This builds a new system generation with the latest packages and services
2637 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2638 your system includes the latest security updates (@pxref{Security Updates}).
2640 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2642 @cindex sudo vs. @command{guix pull}
2643 Note that @command{sudo guix} runs your user's @command{guix} command and
2644 @emph{not} root's, because @command{sudo} leaves @env{PATH} unchanged. To
2645 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2647 The difference matters here, because @command{guix pull} updates
2648 the @command{guix} command and package definitions only for the user it is run
2649 as. This means that if you choose to use @command{guix system reconfigure} in
2650 root's login shell, you'll need to @command{guix pull} separately.
2653 Now, @pxref{Getting Started}, and
2654 join us on @code{#guix} on the Freenode IRC network or on
2655 @email{guix-devel@@gnu.org} to share your experience!
2658 @node Installing Guix in a VM
2659 @section Installing Guix in a Virtual Machine
2661 @cindex virtual machine, Guix System installation
2662 @cindex virtual private server (VPS)
2663 @cindex VPS (virtual private server)
2664 If you'd like to install Guix System in a virtual machine (VM) or on a
2665 virtual private server (VPS) rather than on your beloved machine, this
2668 To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
2669 disk image, follow these steps:
2673 First, retrieve and decompress the Guix system installation image as
2674 described previously (@pxref{USB Stick and DVD Installation}).
2677 Create a disk image that will hold the installed system. To make a
2678 qcow2-formatted disk image, use the @command{qemu-img} command:
2681 qemu-img create -f qcow2 guix-system.img 50G
2684 The resulting file will be much smaller than 50 GB (typically less than
2685 1 MB), but it will grow as the virtualized storage device is filled up.
2688 Boot the USB installation image in an VM:
2691 qemu-system-x86_64 -m 1024 -smp 1 -enable-kvm \
2692 -nic user,model=virtio-net-pci -boot menu=on,order=d \
2693 -drive file=guix-system.img \
2694 -drive media=cdrom,file=guix-system-install-@value{VERSION}.@var{system}.iso
2697 @code{-enable-kvm} is optional, but significantly improves performance,
2698 @pxref{Running Guix in a VM}.
2701 You're now root in the VM, proceed with the installation process.
2702 @xref{Preparing for Installation}, and follow the instructions.
2705 Once installation is complete, you can boot the system that's on your
2706 @file{guix-system.img} image. @xref{Running Guix in a VM}, for how to do
2709 @node Building the Installation Image
2710 @section Building the Installation Image
2712 @cindex installation image
2713 The installation image described above was built using the @command{guix
2714 system} command, specifically:
2717 guix system image -t iso9660 gnu/system/install.scm
2720 Have a look at @file{gnu/system/install.scm} in the source tree,
2721 and see also @ref{Invoking guix system} for more information
2722 about the installation image.
2724 @section Building the Installation Image for ARM Boards
2726 Many ARM boards require a specific variant of the
2727 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2729 If you build a disk image and the bootloader is not available otherwise
2730 (on another boot drive etc), it's advisable to build an image that
2731 includes the bootloader, specifically:
2734 guix system image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2737 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2738 board, a list of possible boards will be printed.
2740 @c *********************************************************************
2741 @node Getting Started
2742 @chapter Getting Started
2744 Presumably, you've reached this section because either you have
2745 installed Guix on top of another distribution (@pxref{Installation}), or
2746 you've installed the standalone Guix System (@pxref{System
2747 Installation}). It's time for you to get started using Guix and this
2748 section aims to help you do that and give you a feel of what it's like.
2750 Guix is about installing software, so probably the first thing you'll
2751 want to do is to actually look for software. Let's say you're looking
2752 for a text editor, you can run:
2755 guix search text editor
2758 This command shows you a number of matching @dfn{packages}, each time
2759 showing the package's name, version, a description, and additional info.
2760 Once you've found out the one you want to use, let's say Emacs (ah ha!),
2761 you can go ahead and install it (run this command as a regular user,
2762 @emph{no need for root privileges}!):
2769 You've installed your first package, congrats! The package is now
2770 visible in your default @dfn{profile}, @file{$HOME/.guix-profile}---a
2771 profile is a directory containing installed packages.
2772 In the process, you've
2773 probably noticed that Guix downloaded pre-built binaries; or, if you
2774 explicitly chose to @emph{not} use pre-built binaries, then probably
2775 Guix is still building software (@pxref{Substitutes}, for more info).
2777 Unless you're using Guix System, the @command{guix install} command must
2778 have printed this hint:
2781 hint: Consider setting the necessary environment variables by running:
2783 GUIX_PROFILE="$HOME/.guix-profile"
2784 . "$GUIX_PROFILE/etc/profile"
2786 Alternately, see `guix package --search-paths -p "$HOME/.guix-profile"'.
2789 Indeed, you must now tell your shell where @command{emacs} and other
2790 programs installed with Guix are to be found. Pasting the two lines
2791 above will do just that: it will add
2792 @code{$HOME/.guix-profile/bin}---which is where the installed package
2793 is---to the @code{PATH} environment variable. You can paste these two
2794 lines in your shell so they take effect right away, but more importantly
2795 you should add them to @file{~/.bash_profile} (or equivalent file if you
2796 do not use Bash) so that environment variables are set next time you
2797 spawn a shell. You only need to do this once and other search paths
2798 environment variables will be taken care of similarly---e.g., if you
2799 eventually install @code{python} and Python libraries, @code{PYTHONPATH}
2802 You can go on installing packages at your will. To list installed
2806 guix package --list-installed
2809 To remove a package, you would unsurprisingly run @command{guix remove}.
2810 A distinguishing feature is the ability to @dfn{roll back} any operation
2811 you made---installation, removal, upgrade---by simply typing:
2814 guix package --roll-back
2817 This is because each operation is in fact a @dfn{transaction} that
2818 creates a new @dfn{generation}. These generations and the difference
2819 between them can be displayed by running:
2822 guix package --list-generations
2825 Now you know the basics of package management!
2827 @quotation Going further
2828 @xref{Package Management}, for more about package management. You may
2829 like @dfn{declarative} package management with @command{guix package
2830 --manifest}, managing separate @dfn{profiles} with @option{--profile},
2831 deleting old generations, collecting garbage, and other nifty features
2832 that will come in handy as you become more familiar with Guix. If you
2833 are a developer, @pxref{Development} for additional tools. And if
2834 you're curious, @pxref{Features}, to peek under the hood.
2837 Once you've installed a set of packages, you will want to periodically
2838 @emph{upgrade} them to the latest and greatest version. To do that, you
2839 will first pull the latest revision of Guix and its package collection:
2845 The end result is a new @command{guix} command, under
2846 @file{~/.config/guix/current/bin}. Unless you're on Guix System, the
2847 first time you run @command{guix pull}, be sure to follow the hint that
2848 the command prints and, similar to what we saw above, paste these two
2849 lines in your terminal and @file{.bash_profile}:
2852 GUIX_PROFILE="$HOME/.config/guix/current"
2853 . "$GUIX_PROFILE/etc/profile"
2857 You must also instruct your shell to point to this new @command{guix}:
2863 At this point, you're running a brand new Guix. You can thus go ahead
2864 and actually upgrade all the packages you previously installed:
2870 As you run this command, you will see that binaries are downloaded (or
2871 perhaps some packages are built), and eventually you end up with the
2872 upgraded packages. Should one of these upgraded packages not be to your
2873 liking, remember you can always roll back!
2875 You can display the exact revision of Guix you're currently using by
2882 The information it displays is @emph{all it takes to reproduce the exact
2883 same Guix}, be it at a different point in time or on a different
2886 @quotation Going further
2887 @xref{Invoking guix pull}, for more information. @xref{Channels}, on
2888 how to specify additional @dfn{channels} to pull packages from, how to
2889 replicate Guix, and more. You may also find @command{time-machine}
2890 handy (@pxref{Invoking guix time-machine}).
2893 If you installed Guix System, one of the first things you'll want to do
2894 is to upgrade your system. Once you've run @command{guix pull} to get
2895 the latest Guix, you can upgrade the system like this:
2898 sudo guix system reconfigure /etc/config.scm
2901 Upon completion, the system runs the latest versions of its software
2902 packages. When you eventually reboot, you'll notice a sub-menu in the
2903 bootloader that reads ``Old system generations'': it's what allows you
2904 to boot @emph{an older generation of your system}, should the latest
2905 generation be ``broken'' or otherwise unsatisfying. Just like for
2906 packages, you can always @emph{roll back} to a previous generation
2907 @emph{of the whole system}:
2910 sudo guix system roll-back
2913 There are many things you'll probably want to tweak on your system:
2914 adding new user accounts, adding new system services, fiddling with the
2915 configuration of those services, etc. The system configuration is
2916 @emph{entirely} described in the @file{/etc/config.scm} file.
2917 @xref{Using the Configuration System}, to learn how to change it.
2919 Now you know enough to get started!
2921 @quotation Resources
2922 The rest of this manual provides a reference for all things Guix. Here
2923 are some additional resources you may find useful:
2927 @xref{Top,,, guix-cookbook, The GNU Guix Cookbook}, for a list of
2928 ``how-to'' style of recipes for a variety of applications.
2931 The @uref{https://guix.gnu.org/guix-refcard.pdf, GNU Guix Reference
2932 Card} lists in two pages most of the commands and options you'll ever
2936 The web site contains @uref{https://guix.gnu.org/en/videos/,
2937 instructional videos} covering topics such as everyday use of Guix, how
2938 to get help, and how to become a contributor.
2941 @xref{Documentation}, to learn how to access documentation on your
2945 We hope you will enjoy Guix as much as the community enjoys building it!
2948 @c *********************************************************************
2949 @node Package Management
2950 @chapter Package Management
2953 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2954 remove software packages, without having to know about their build
2955 procedures or dependencies. Guix also goes beyond this obvious set of
2958 This chapter describes the main features of Guix, as well as the
2959 package management tools it provides. Along with the command-line
2960 interface described below (@pxref{Invoking guix package, @code{guix
2961 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2962 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2963 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2967 guix install emacs-guix
2971 * Features:: How Guix will make your life brighter.
2972 * Invoking guix package:: Package installation, removal, etc.
2973 * Substitutes:: Downloading pre-built binaries.
2974 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2975 * Invoking guix gc:: Running the garbage collector.
2976 * Invoking guix pull:: Fetching the latest Guix and distribution.
2977 * Invoking guix time-machine:: Running an older revision of Guix.
2978 * Inferiors:: Interacting with another revision of Guix.
2979 * Invoking guix describe:: Display information about your Guix revision.
2980 * Invoking guix archive:: Exporting and importing store files.
2986 Here we assume you've already made your first steps with Guix
2987 (@pxref{Getting Started}) and would like to get an overview about what's
2988 going on under the hood.
2990 When using Guix, each package ends up in the @dfn{package store}, in its
2991 own directory---something that resembles
2992 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2994 Instead of referring to these directories, users have their own
2995 @dfn{profile}, which points to the packages that they actually want to
2996 use. These profiles are stored within each user's home directory, at
2997 @code{$HOME/.guix-profile}.
2999 For example, @code{alice} installs GCC 4.7.2. As a result,
3000 @file{/home/alice/.guix-profile/bin/gcc} points to
3001 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
3002 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
3003 simply continues to point to
3004 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
3005 coexist on the same system without any interference.
3007 The @command{guix package} command is the central tool to manage
3008 packages (@pxref{Invoking guix package}). It operates on the per-user
3009 profiles, and can be used @emph{with normal user privileges}.
3011 @cindex transactions
3012 The command provides the obvious install, remove, and upgrade
3013 operations. Each invocation is actually a @emph{transaction}: either
3014 the specified operation succeeds, or nothing happens. Thus, if the
3015 @command{guix package} process is terminated during the transaction,
3016 or if a power outage occurs during the transaction, then the user's
3017 profile remains in its previous state, and remains usable.
3019 In addition, any package transaction may be @emph{rolled back}. So, if,
3020 for example, an upgrade installs a new version of a package that turns
3021 out to have a serious bug, users may roll back to the previous instance
3022 of their profile, which was known to work well. Similarly, the global
3023 system configuration on Guix is subject to
3024 transactional upgrades and roll-back
3025 (@pxref{Using the Configuration System}).
3027 All packages in the package store may be @emph{garbage-collected}.
3028 Guix can determine which packages are still referenced by user
3029 profiles, and remove those that are provably no longer referenced
3030 (@pxref{Invoking guix gc}). Users may also explicitly remove old
3031 generations of their profile so that the packages they refer to can be
3034 @cindex reproducibility
3035 @cindex reproducible builds
3036 Guix takes a @dfn{purely functional} approach to package
3037 management, as described in the introduction (@pxref{Introduction}).
3038 Each @file{/gnu/store} package directory name contains a hash of all the
3039 inputs that were used to build that package---compiler, libraries, build
3040 scripts, etc. This direct correspondence allows users to make sure a
3041 given package installation matches the current state of their
3042 distribution. It also helps maximize @dfn{build reproducibility}:
3043 thanks to the isolated build environments that are used, a given build
3044 is likely to yield bit-identical files when performed on different
3045 machines (@pxref{Invoking guix-daemon, container}).
3048 This foundation allows Guix to support @dfn{transparent binary/source
3049 deployment}. When a pre-built binary for a @file{/gnu/store} item is
3050 available from an external source---a @dfn{substitute}, Guix just
3051 downloads it and unpacks it;
3052 otherwise, it builds the package from source, locally
3053 (@pxref{Substitutes}). Because build results are usually bit-for-bit
3054 reproducible, users do not have to trust servers that provide
3055 substitutes: they can force a local build and @emph{challenge} providers
3056 (@pxref{Invoking guix challenge}).
3058 Control over the build environment is a feature that is also useful for
3059 developers. The @command{guix environment} command allows developers of
3060 a package to quickly set up the right development environment for their
3061 package, without having to manually install the dependencies of the
3062 package into their profile (@pxref{Invoking guix environment}).
3064 @cindex replication, of software environments
3065 @cindex provenance tracking, of software artifacts
3066 All of Guix and its package definitions is version-controlled, and
3067 @command{guix pull} allows you to ``travel in time'' on the history of Guix
3068 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
3069 Guix instance on a different machine or at a later point in time, which in
3070 turn allows you to @emph{replicate complete software environments}, while
3071 retaining precise @dfn{provenance tracking} of the software.
3073 @node Invoking guix package
3074 @section Invoking @command{guix package}
3076 @cindex installing packages
3077 @cindex removing packages
3078 @cindex package installation
3079 @cindex package removal
3081 The @command{guix package} command is the tool that allows users to
3082 install, upgrade, and remove packages, as well as rolling back to
3083 previous configurations. These operations work on a user
3084 @dfn{profile}---a directory of installed packages. Each user has a
3085 default profile in @file{$HOME/.guix-profile}.
3086 The command operates only on the user's own profile,
3087 and works with normal user privileges (@pxref{Features}). Its syntax
3091 guix package @var{options}
3094 @cindex transactions
3095 Primarily, @var{options} specifies the operations to be performed during
3096 the transaction. Upon completion, a new profile is created, but
3097 previous @dfn{generations} of the profile remain available, should the user
3100 For example, to remove @code{lua} and install @code{guile} and
3101 @code{guile-cairo} in a single transaction:
3104 guix package -r lua -i guile guile-cairo
3107 @cindex aliases, for @command{guix package}
3108 For your convenience, we also provide the following aliases:
3112 @command{guix search} is an alias for @command{guix package -s},
3114 @command{guix install} is an alias for @command{guix package -i},
3116 @command{guix remove} is an alias for @command{guix package -r},
3118 @command{guix upgrade} is an alias for @command{guix package -u},
3120 and @command{guix show} is an alias for @command{guix package --show=}.
3123 These aliases are less expressive than @command{guix package} and provide
3124 fewer options, so in some cases you'll probably want to use @command{guix
3127 @command{guix package} also supports a @dfn{declarative approach}
3128 whereby the user specifies the exact set of packages to be available and
3129 passes it @i{via} the @option{--manifest} option
3130 (@pxref{profile-manifest, @option{--manifest}}).
3133 For each user, a symlink to the user's default profile is automatically
3134 created in @file{$HOME/.guix-profile}. This symlink always points to the
3135 current generation of the user's default profile. Thus, users can add
3136 @file{$HOME/.guix-profile/bin} to their @env{PATH} environment
3137 variable, and so on.
3138 @cindex search paths
3139 If you are not using Guix System, consider adding the
3140 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
3141 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
3142 shells get all the right environment variable definitions:
3145 GUIX_PROFILE="$HOME/.guix-profile" ; \
3146 source "$GUIX_PROFILE/etc/profile"
3149 In a multi-user setup, user profiles are stored in a place registered as
3150 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
3151 to (@pxref{Invoking guix gc}). That directory is normally
3152 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
3153 @var{localstatedir} is the value passed to @code{configure} as
3154 @option{--localstatedir}, and @var{user} is the user name. The
3155 @file{per-user} directory is created when @command{guix-daemon} is
3156 started, and the @var{user} sub-directory is created by @command{guix
3159 The @var{options} can be among the following:
3163 @item --install=@var{package} @dots{}
3164 @itemx -i @var{package} @dots{}
3165 Install the specified @var{package}s.
3167 Each @var{package} may specify either a simple package name, such as
3168 @code{guile}, or a package name followed by an at-sign and version number,
3169 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
3170 case, the newest version prefixed by @code{1.8} is selected).
3172 If no version number is specified, the
3173 newest available version will be selected. In addition, @var{package}
3174 may contain a colon, followed by the name of one of the outputs of the
3175 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
3176 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
3177 name (and optionally version) are searched for among the GNU
3178 distribution modules (@pxref{Package Modules}).
3180 @cindex propagated inputs
3181 Sometimes packages have @dfn{propagated inputs}: these are dependencies
3182 that automatically get installed along with the required package
3183 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
3184 @code{package} objects}, for information about propagated inputs in
3185 package definitions).
3187 @anchor{package-cmd-propagated-inputs}
3188 An example is the GNU MPC library: its C header files refer to those of
3189 the GNU MPFR library, which in turn refer to those of the GMP library.
3190 Thus, when installing MPC, the MPFR and GMP libraries also get installed
3191 in the profile; removing MPC also removes MPFR and GMP---unless they had
3192 also been explicitly installed by the user.
3194 Besides, packages sometimes rely on the definition of environment
3195 variables for their search paths (see explanation of
3196 @option{--search-paths} below). Any missing or possibly incorrect
3197 environment variable definitions are reported here.
3199 @item --install-from-expression=@var{exp}
3201 Install the package @var{exp} evaluates to.
3203 @var{exp} must be a Scheme expression that evaluates to a
3204 @code{<package>} object. This option is notably useful to disambiguate
3205 between same-named variants of a package, with expressions such as
3206 @code{(@@ (gnu packages base) guile-final)}.
3208 Note that this option installs the first output of the specified
3209 package, which may be insufficient when needing a specific output of a
3210 multiple-output package.
3212 @item --install-from-file=@var{file}
3213 @itemx -f @var{file}
3214 Install the package that the code within @var{file} evaluates to.
3216 As an example, @var{file} might contain a definition like this
3217 (@pxref{Defining Packages}):
3220 @include package-hello.scm
3223 Developers may find it useful to include such a @file{guix.scm} file
3224 in the root of their project source tree that can be used to test
3225 development snapshots and create reproducible development environments
3226 (@pxref{Invoking guix environment}).
3228 The @var{file} may also contain a JSON representation of one or more
3229 package definitions. Running @code{guix package -f} on
3230 @file{hello.json} with the following contents would result in installing
3231 the package @code{greeter} after building @code{myhello}:
3234 @verbatiminclude package-hello.json
3237 @item --remove=@var{package} @dots{}
3238 @itemx -r @var{package} @dots{}
3239 Remove the specified @var{package}s.
3241 As for @option{--install}, each @var{package} may specify a version number
3242 and/or output name in addition to the package name. For instance,
3243 @samp{-r glibc:debug} would remove the @code{debug} output of
3246 @item --upgrade[=@var{regexp} @dots{}]
3247 @itemx -u [@var{regexp} @dots{}]
3248 @cindex upgrading packages
3249 Upgrade all the installed packages. If one or more @var{regexp}s are
3250 specified, upgrade only installed packages whose name matches a
3251 @var{regexp}. Also see the @option{--do-not-upgrade} option below.
3253 Note that this upgrades package to the latest version of packages found
3254 in the distribution currently installed. To update your distribution,
3255 you should regularly run @command{guix pull} (@pxref{Invoking guix
3258 @cindex package transformations, upgrades
3259 When upgrading, package transformations that were originally applied
3260 when creating the profile are automatically re-applied (@pxref{Package
3261 Transformation Options}). For example, assume you first installed Emacs
3262 from the tip of its development branch with:
3265 guix install emacs-next --with-branch=emacs-next=master
3268 Next time you run @command{guix upgrade}, Guix will again pull the tip
3269 of the Emacs development branch and build @code{emacs-next} from that
3272 Note that transformation options such as @option{--with-branch} and
3273 @option{--with-source} depend on external state; it is up to you to
3274 ensure that they work as expected. You can also discard a
3275 transformations that apply to a package by running:
3278 guix install @var{package}
3281 @item --do-not-upgrade[=@var{regexp} @dots{}]
3282 When used together with the @option{--upgrade} option, do @emph{not}
3283 upgrade any packages whose name matches a @var{regexp}. For example, to
3284 upgrade all packages in the current profile except those containing the
3285 substring ``emacs'':
3288 $ guix package --upgrade . --do-not-upgrade emacs
3291 @item @anchor{profile-manifest}--manifest=@var{file}
3292 @itemx -m @var{file}
3293 @cindex profile declaration
3294 @cindex profile manifest
3295 Create a new generation of the profile from the manifest object
3296 returned by the Scheme code in @var{file}. This option can be repeated
3297 several times, in which case the manifests are concatenated.
3299 This allows you to @emph{declare} the profile's contents rather than
3300 constructing it through a sequence of @option{--install} and similar
3301 commands. The advantage is that @var{file} can be put under version
3302 control, copied to different machines to reproduce the same profile, and
3305 @c FIXME: Add reference to (guix profile) documentation when available.
3306 @var{file} must return a @dfn{manifest} object, which is roughly a list
3309 @findex packages->manifest
3311 (use-package-modules guile emacs)
3316 ;; Use a specific package output.
3317 (list guile-2.0 "debug")))
3320 @findex specifications->manifest
3321 In this example we have to know which modules define the @code{emacs}
3322 and @code{guile-2.0} variables to provide the right
3323 @code{use-package-modules} line, which can be cumbersome. We can
3324 instead provide regular package specifications and let
3325 @code{specifications->manifest} look up the corresponding package
3329 (specifications->manifest
3330 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
3333 @xref{export-manifest, @option{--export-manifest}}, to learn how to
3334 obtain a manifest file from an existing profile.
3337 @cindex rolling back
3338 @cindex undoing transactions
3339 @cindex transactions, undoing
3340 Roll back to the previous @dfn{generation} of the profile---i.e., undo
3341 the last transaction.
3343 When combined with options such as @option{--install}, roll back occurs
3344 before any other actions.
3346 When rolling back from the first generation that actually contains
3347 installed packages, the profile is made to point to the @dfn{zeroth
3348 generation}, which contains no files apart from its own metadata.
3350 After having rolled back, installing, removing, or upgrading packages
3351 overwrites previous future generations. Thus, the history of the
3352 generations in a profile is always linear.
3354 @item --switch-generation=@var{pattern}
3355 @itemx -S @var{pattern}
3357 Switch to a particular generation defined by @var{pattern}.
3359 @var{pattern} may be either a generation number or a number prefixed
3360 with ``+'' or ``-''. The latter means: move forward/backward by a
3361 specified number of generations. For example, if you want to return to
3362 the latest generation after @option{--roll-back}, use
3363 @option{--switch-generation=+1}.
3365 The difference between @option{--roll-back} and
3366 @option{--switch-generation=-1} is that @option{--switch-generation} will
3367 not make a zeroth generation, so if a specified generation does not
3368 exist, the current generation will not be changed.
3370 @item --search-paths[=@var{kind}]
3371 @cindex search paths
3372 Report environment variable definitions, in Bash syntax, that may be
3373 needed in order to use the set of installed packages. These environment
3374 variables are used to specify @dfn{search paths} for files used by some
3375 of the installed packages.
3377 For example, GCC needs the @env{CPATH} and @env{LIBRARY_PATH}
3378 environment variables to be defined so it can look for headers and
3379 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
3380 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
3381 library are installed in the profile, then @option{--search-paths} will
3382 suggest setting these variables to @file{@var{profile}/include} and
3383 @file{@var{profile}/lib}, respectively.
3385 The typical use case is to define these environment variables in the
3389 $ eval `guix package --search-paths`
3392 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
3393 meaning that the returned environment variable definitions will either
3394 be exact settings, or prefixes or suffixes of the current value of these
3395 variables. When omitted, @var{kind} defaults to @code{exact}.
3397 This option can also be used to compute the @emph{combined} search paths
3398 of several profiles. Consider this example:
3401 $ guix package -p foo -i guile
3402 $ guix package -p bar -i guile-json
3403 $ guix package -p foo -p bar --search-paths
3406 The last command above reports about the @env{GUILE_LOAD_PATH}
3407 variable, even though, taken individually, neither @file{foo} nor
3408 @file{bar} would lead to that recommendation.
3411 @cindex profile, choosing
3412 @item --profile=@var{profile}
3413 @itemx -p @var{profile}
3414 Use @var{profile} instead of the user's default profile.
3416 @var{profile} must be the name of a file that will be created upon
3417 completion. Concretely, @var{profile} will be a mere symbolic link
3418 (``symlink'') pointing to the actual profile where packages are
3422 $ guix install hello -p ~/code/my-profile
3424 $ ~/code/my-profile/bin/hello
3428 All it takes to get rid of the profile is to remove this symlink and its
3429 siblings that point to specific generations:
3432 $ rm ~/code/my-profile ~/code/my-profile-*-link
3435 @item --list-profiles
3436 List all the user's profiles:
3439 $ guix package --list-profiles
3440 /home/charlie/.guix-profile
3441 /home/charlie/code/my-profile
3442 /home/charlie/code/devel-profile
3443 /home/charlie/tmp/test
3446 When running as root, list all the profiles of all the users.
3448 @cindex collisions, in a profile
3449 @cindex colliding packages in profiles
3450 @cindex profile collisions
3451 @item --allow-collisions
3452 Allow colliding packages in the new profile. Use at your own risk!
3454 By default, @command{guix package} reports as an error @dfn{collisions}
3455 in the profile. Collisions happen when two or more different versions
3456 or variants of a given package end up in the profile.
3459 Use the bootstrap Guile to build the profile. This option is only
3460 useful to distribution developers.
3464 In addition to these actions, @command{guix package} supports the
3465 following options to query the current state of a profile, or the
3466 availability of packages:
3470 @item --search=@var{regexp}
3471 @itemx -s @var{regexp}
3472 @anchor{guix-search}
3473 @cindex searching for packages
3474 List the available packages whose name, synopsis, or description matches
3475 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
3476 Print all the metadata of matching packages in
3477 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
3478 GNU recutils manual}).
3480 This allows specific fields to be extracted using the @command{recsel}
3481 command, for instance:
3484 $ guix package -s malloc | recsel -p name,version,relevance
3498 Similarly, to show the name of all the packages available under the
3499 terms of the GNU@tie{}LGPL version 3:
3502 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
3509 It is also possible to refine search results using several @code{-s} flags to
3510 @command{guix package}, or several arguments to @command{guix search}. For
3511 example, the following command returns a list of board games (this time using
3512 the @command{guix search} alias):
3515 $ guix search '\<board\>' game | recsel -p name
3520 If we were to omit @code{-s game}, we would also get software packages
3521 that deal with printed circuit boards; removing the angle brackets
3522 around @code{board} would further add packages that have to do with
3525 And now for a more elaborate example. The following command searches
3526 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
3527 libraries, and prints the name and synopsis of the matching packages:
3530 $ guix search crypto library | \
3531 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
3535 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
3536 information on @dfn{selection expressions} for @code{recsel -e}.
3538 @item --show=@var{package}
3539 Show details about @var{package}, taken from the list of available packages, in
3540 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
3544 $ guix package --show=python | recsel -p name,version
3552 You may also specify the full name of a package to only get details about a
3553 specific version of it (this time using the @command{guix show} alias):
3555 $ guix show python@@3.4 | recsel -p name,version
3562 @item --list-installed[=@var{regexp}]
3563 @itemx -I [@var{regexp}]
3564 List the currently installed packages in the specified profile, with the
3565 most recently installed packages shown last. When @var{regexp} is
3566 specified, list only installed packages whose name matches @var{regexp}.
3568 For each installed package, print the following items, separated by
3569 tabs: the package name, its version string, the part of the package that
3570 is installed (for instance, @code{out} for the default output,
3571 @code{include} for its headers, etc.), and the path of this package in
3574 @item --list-available[=@var{regexp}]
3575 @itemx -A [@var{regexp}]
3576 List packages currently available in the distribution for this system
3577 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3578 available packages whose name matches @var{regexp}.
3580 For each package, print the following items separated by tabs: its name,
3581 its version string, the parts of the package (@pxref{Packages with
3582 Multiple Outputs}), and the source location of its definition.
3584 @item --list-generations[=@var{pattern}]
3585 @itemx -l [@var{pattern}]
3587 Return a list of generations along with their creation dates; for each
3588 generation, show the installed packages, with the most recently
3589 installed packages shown last. Note that the zeroth generation is never
3592 For each installed package, print the following items, separated by
3593 tabs: the name of a package, its version string, the part of the package
3594 that is installed (@pxref{Packages with Multiple Outputs}), and the
3595 location of this package in the store.
3597 When @var{pattern} is used, the command returns only matching
3598 generations. Valid patterns include:
3601 @item @emph{Integers and comma-separated integers}. Both patterns denote
3602 generation numbers. For instance, @option{--list-generations=1} returns
3605 And @option{--list-generations=1,8,2} outputs three generations in the
3606 specified order. Neither spaces nor trailing commas are allowed.
3608 @item @emph{Ranges}. @option{--list-generations=2..9} prints the
3609 specified generations and everything in between. Note that the start of
3610 a range must be smaller than its end.
3612 It is also possible to omit the endpoint. For example,
3613 @option{--list-generations=2..}, returns all generations starting from the
3616 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3617 or months by passing an integer along with the first letter of the
3618 duration. For example, @option{--list-generations=20d} lists generations
3619 that are up to 20 days old.
3622 @item --delete-generations[=@var{pattern}]
3623 @itemx -d [@var{pattern}]
3624 When @var{pattern} is omitted, delete all generations except the current
3627 This command accepts the same patterns as @option{--list-generations}.
3628 When @var{pattern} is specified, delete the matching generations. When
3629 @var{pattern} specifies a duration, generations @emph{older} than the
3630 specified duration match. For instance, @option{--delete-generations=1m}
3631 deletes generations that are more than one month old.
3633 If the current generation matches, it is @emph{not} deleted. Also, the
3634 zeroth generation is never deleted.
3636 Note that deleting generations prevents rolling back to them.
3637 Consequently, this command must be used with care.
3639 @cindex manifest, exporting
3640 @anchor{export-manifest}
3641 @item --export-manifest
3642 Write to standard output a manifest suitable for @option{--manifest}
3643 corresponding to the chosen profile(s).
3645 This option is meant to help you migrate from the ``imperative''
3646 operating mode---running @command{guix install}, @command{guix upgrade},
3647 etc.---to the declarative mode that @option{--manifest} offers.
3649 Be aware that the resulting manifest @emph{approximates} what your
3650 profile actually contains; for instance, depending on how your profile
3651 was created, it can refer to packages or package versions that are not
3652 exactly what you specified.
3654 Keep in mind that a manifest is purely symbolic: it only contains
3655 package names and possibly versions, and their meaning varies over time.
3656 If you wish to ``pin'' channels to the revisions that were used to build
3657 the profile(s), see @option{--export-channels} below.
3659 @cindex pinning, channel revisions of a profile
3660 @item --export-channels
3661 Write to standard output the list of channels used by the chosen
3662 profile(s), in a format suitable for @command{guix pull --channels} or
3663 @command{guix time-machine --channels} (@pxref{Channels}).
3665 Together with @option{--export-manifest}, this option provides
3666 information allowing you to replicate the current profile
3667 (@pxref{Replicating Guix}).
3669 However, note that the output of this command @emph{approximates} what
3670 was actually used to build this profile. In particular, a single
3671 profile might have been built from several different revisions of the
3672 same channel. In that case, @option{--export-manifest} chooses the last
3673 one and writes the list of other revisions in a comment. If you really
3674 need to pick packages from different channel revisions, you can use
3675 inferiors in your manifest to do so (@pxref{Inferiors}).
3677 Together with @option{--export-manifest}, this is a good starting point
3678 if you are willing to migrate from the ``imperative'' model to the fully
3679 declarative model consisting of a manifest file along with a channels
3680 file pinning the exact channel revision(s) you want.
3683 Finally, since @command{guix package} may actually start build
3684 processes, it supports all the common build options (@pxref{Common Build
3685 Options}). It also supports package transformation options, such as
3686 @option{--with-source}, and preserves them across upgrades
3687 (@pxref{Package Transformation Options}).
3690 @section Substitutes
3693 @cindex pre-built binaries
3694 Guix supports transparent source/binary deployment, which means that it
3695 can either build things locally, or download pre-built items from a
3696 server, or both. We call these pre-built items @dfn{substitutes}---they
3697 are substitutes for local build results. In many cases, downloading a
3698 substitute is much faster than building things locally.
3700 Substitutes can be anything resulting from a derivation build
3701 (@pxref{Derivations}). Of course, in the common case, they are
3702 pre-built package binaries, but source tarballs, for instance, which
3703 also result from derivation builds, can be available as substitutes.
3706 * Official Substitute Server:: One particular source of substitutes.
3707 * Substitute Server Authorization:: How to enable or disable substitutes.
3708 * Getting Substitutes from Other Servers:: Substitute diversity.
3709 * Substitute Authentication:: How Guix verifies substitutes.
3710 * Proxy Settings:: How to get substitutes via proxy.
3711 * Substitution Failure:: What happens when substitution fails.
3712 * On Trusting Binaries:: How can you trust that binary blob?
3715 @node Official Substitute Server
3716 @subsection Official Substitute Server
3719 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
3720 that builds packages from Guix continuously for some
3721 architectures, and makes them available as substitutes. This is the
3722 default source of substitutes; it can be overridden by passing the
3723 @option{--substitute-urls} option either to @command{guix-daemon}
3724 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3725 or to client tools such as @command{guix package}
3726 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3729 Substitute URLs can be either HTTP or HTTPS.
3730 HTTPS is recommended because communications are encrypted; conversely,
3731 using HTTP makes all communications visible to an eavesdropper, who
3732 could use the information gathered to determine, for instance, whether
3733 your system has unpatched security vulnerabilities.
3735 Substitutes from the official build farm are enabled by default when
3736 using Guix System (@pxref{GNU Distribution}). However,
3737 they are disabled by default when using Guix on a foreign distribution,
3738 unless you have explicitly enabled them via one of the recommended
3739 installation steps (@pxref{Installation}). The following paragraphs
3740 describe how to enable or disable substitutes for the official build
3741 farm; the same procedure can also be used to enable substitutes for any
3742 other substitute server.
3744 @node Substitute Server Authorization
3745 @subsection Substitute Server Authorization
3748 @cindex substitutes, authorization thereof
3749 @cindex access control list (ACL), for substitutes
3750 @cindex ACL (access control list), for substitutes
3751 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
3753 must add its public key to the access control list (ACL) of archive
3754 imports, using the @command{guix archive} command (@pxref{Invoking guix
3755 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
3756 be compromised and to serve genuine substitutes.
3759 If you are using Guix System, you can skip this section: Guix System
3760 authorizes substitutes from @code{@value{SUBSTITUTE-SERVER}} by default.
3763 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
3764 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
3765 the installation prefix of Guix. If you installed Guix from source,
3766 make sure you checked the GPG signature of
3767 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3768 Then, you can run something like this:
3771 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
3774 Once this is in place, the output of a command like @code{guix build}
3775 should change from something like:
3778 $ guix build emacs --dry-run
3779 The following derivations would be built:
3780 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3781 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3782 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3783 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3791 $ guix build emacs --dry-run
3792 112.3 MB would be downloaded:
3793 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3794 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3795 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3796 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3801 The text changed from ``The following derivations would be built'' to
3802 ``112.3 MB would be downloaded''. This indicates that substitutes from
3803 @code{@value{SUBSTITUTE-SERVER}} are usable and will be downloaded, when
3804 possible, for future builds.
3806 @cindex substitutes, how to disable
3807 The substitute mechanism can be disabled globally by running
3808 @code{guix-daemon} with @option{--no-substitutes} (@pxref{Invoking
3809 guix-daemon}). It can also be disabled temporarily by passing the
3810 @option{--no-substitutes} option to @command{guix package},
3811 @command{guix build}, and other command-line tools.
3813 @node Getting Substitutes from Other Servers
3814 @subsection Getting Substitutes from Other Servers
3816 @cindex substitute servers, adding more
3817 Guix can look up and fetch substitutes from several servers. This is
3818 useful when you are using packages from additional channels for which
3819 the official server does not have substitutes but another server
3820 provides them. Another situation where this is useful is when you would
3821 prefer to download from your organization's substitute server, resorting
3822 to the official server only as a fallback or dismissing it altogether.
3824 You can give Guix a list of substitute server URLs and it will check
3825 them in the specified order. You also need to explicitly authorize the
3826 public keys of substitute servers to instruct Guix to accept the
3827 substitutes they sign.
3829 On Guix System, this is achieved by modifying the configuration of the
3830 @code{guix} service. Since the @code{guix} service is part of the
3831 default lists of services, @code{%base-services} and
3832 @code{%desktop-services}, you can use @code{modify-services} to change
3833 its configuration and add the URLs and substitute keys that you want
3834 (@pxref{Service Reference, @code{modify-services}}).
3836 As an example, suppose you want to fetch substitutes from
3837 @code{guix.example.org} and to authorize the signing key of that server,
3838 in addition to the default @code{@value{SUBSTITUTE-SERVER}}. The
3839 resulting operating system configuration will look something like:
3845 ;; Assume we're starting from '%desktop-services'. Replace it
3846 ;; with the list of services you're actually using.
3847 (modify-services %desktop-services
3848 (guix-service-type config =>
3852 (append (list "https://guix.example.org")
3853 %default-substitute-urls))
3855 (append (list (local-file "./key.pub"))
3856 %default-authorized-guix-keys)))))))
3859 This assumes that the file @file{key.pub} contains the signing key of
3860 @code{guix.example.org}. With this change in place in your operating
3861 system configuration file (say @file{/etc/config.scm}), you can
3862 reconfigure and restart the @code{guix-daemon} service or reboot so the
3863 changes take effect:
3866 $ sudo guix system reconfigure /etc/config.scm
3867 $ sudo herd restart guix-daemon
3870 If you're running Guix on a ``foreign distro'', you would instead take
3871 the following steps to get substitutes from additional servers:
3875 Edit the service configuration file for @code{guix-daemon}; when using
3876 systemd, this is normally
3877 @file{/etc/systemd/system/guix-daemon.service}. Add the
3878 @option{--substitute-urls} option on the @command{guix-daemon} command
3879 line and list the URLs of interest (@pxref{daemon-substitute-urls,
3880 @code{guix-daemon --substitute-urls}}):
3883 @dots{} --substitute-urls='https://guix.example.org https://@value{SUBSTITUTE-SERVER}'
3887 Restart the daemon. For systemd, it goes like this:
3890 systemctl daemon-reload
3891 systemctl restart guix-daemon.service
3895 Authorize the key of the new server (@pxref{Invoking guix archive}):
3898 guix archive --authorize < key.pub
3901 Again this assumes @file{key.pub} contains the public key that
3902 @code{guix.example.org} uses to sign substitutes.
3905 Now you're all set! Substitutes will be preferably taken from
3906 @code{https://guix.example.org}, using @code{@value{SUBSTITUTE-SERVER}}
3907 as a fallback. Of course you can list as many substitute servers as you
3908 like, with the caveat that substitute lookup can be slowed down if too
3909 many servers need to be contacted.
3911 Note that there are also situations where one may want to add the URL of
3912 a substitute server @emph{without} authorizing its key.
3913 @xref{Substitute Authentication}, to understand this fine point.
3915 @node Substitute Authentication
3916 @subsection Substitute Authentication
3918 @cindex digital signatures
3919 Guix detects and raises an error when attempting to use a substitute
3920 that has been tampered with. Likewise, it ignores substitutes that are
3921 not signed, or that are not signed by one of the keys listed in the ACL.
3923 There is one exception though: if an unauthorized server provides
3924 substitutes that are @emph{bit-for-bit identical} to those provided by
3925 an authorized server, then the unauthorized server becomes eligible for
3926 downloads. For example, assume we have chosen two substitute servers
3930 --substitute-urls="https://a.example.org https://b.example.org"
3934 @cindex reproducible builds
3935 If the ACL contains only the key for @samp{b.example.org}, and if
3936 @samp{a.example.org} happens to serve the @emph{exact same} substitutes,
3937 then Guix will download substitutes from @samp{a.example.org} because it
3938 comes first in the list and can be considered a mirror of
3939 @samp{b.example.org}. In practice, independent build machines usually
3940 produce the same binaries, thanks to bit-reproducible builds (see
3943 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3944 (in other words, the server is not authenticated), contrary to what
3945 HTTPS clients such as Web browsers usually do. This is because Guix
3946 authenticates substitute information itself, as explained above, which
3947 is what we care about (whereas X.509 certificates are about
3948 authenticating bindings between domain names and public keys).
3950 @node Proxy Settings
3951 @subsection Proxy Settings
3955 Substitutes are downloaded over HTTP or HTTPS@. The @env{http_proxy} and
3956 @env{https_proxy} environment variables can be set in the environment of
3957 @command{guix-daemon} and are honored for downloads of substitutes.
3958 Note that the value of those environment variables in the environment
3959 where @command{guix build}, @command{guix package}, and other client
3960 commands are run has @emph{absolutely no effect}.
3962 @node Substitution Failure
3963 @subsection Substitution Failure
3965 Even when a substitute for a derivation is available, sometimes the
3966 substitution attempt will fail. This can happen for a variety of
3967 reasons: the substitute server might be offline, the substitute may
3968 recently have been deleted, the connection might have been interrupted,
3971 When substitutes are enabled and a substitute for a derivation is
3972 available, but the substitution attempt fails, Guix will attempt to
3973 build the derivation locally depending on whether or not
3974 @option{--fallback} was given (@pxref{fallback-option,, common build
3975 option @option{--fallback}}). Specifically, if @option{--fallback} was
3976 omitted, then no local build will be performed, and the derivation is
3977 considered to have failed. However, if @option{--fallback} was given,
3978 then Guix will attempt to build the derivation locally, and the success
3979 or failure of the derivation depends on the success or failure of the
3980 local build. Note that when substitutes are disabled or no substitute
3981 is available for the derivation in question, a local build will
3982 @emph{always} be performed, regardless of whether or not
3983 @option{--fallback} was given.
3985 To get an idea of how many substitutes are available right now, you can
3986 try running the @command{guix weather} command (@pxref{Invoking guix
3987 weather}). This command provides statistics on the substitutes provided
3990 @node On Trusting Binaries
3991 @subsection On Trusting Binaries
3993 @cindex trust, of pre-built binaries
3994 Today, each individual's control over their own computing is at the
3995 mercy of institutions, corporations, and groups with enough power and
3996 determination to subvert the computing infrastructure and exploit its
3997 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
3998 convenient, we encourage users to also build on their own, or even run
3999 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
4000 interesting target. One way to help is by publishing the software you
4001 build using @command{guix publish} so that others have one more choice
4002 of server to download substitutes from (@pxref{Invoking guix publish}).
4004 Guix has the foundations to maximize build reproducibility
4005 (@pxref{Features}). In most cases, independent builds of a given
4006 package or derivation should yield bit-identical results. Thus, through
4007 a diverse set of independent package builds, we can strengthen the
4008 integrity of our systems. The @command{guix challenge} command aims to
4009 help users assess substitute servers, and to assist developers in
4010 finding out about non-deterministic package builds (@pxref{Invoking guix
4011 challenge}). Similarly, the @option{--check} option of @command{guix
4012 build} allows users to check whether previously-installed substitutes
4013 are genuine by rebuilding them locally (@pxref{build-check,
4014 @command{guix build --check}}).
4016 In the future, we want Guix to have support to publish and retrieve
4017 binaries to/from other users, in a peer-to-peer fashion. If you would
4018 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
4020 @node Packages with Multiple Outputs
4021 @section Packages with Multiple Outputs
4023 @cindex multiple-output packages
4024 @cindex package outputs
4027 Often, packages defined in Guix have a single @dfn{output}---i.e., the
4028 source package leads to exactly one directory in the store. When running
4029 @command{guix install glibc}, one installs the default output of the
4030 GNU libc package; the default output is called @code{out}, but its name
4031 can be omitted as shown in this command. In this particular case, the
4032 default output of @code{glibc} contains all the C header files, shared
4033 libraries, static libraries, Info documentation, and other supporting
4036 Sometimes it is more appropriate to separate the various types of files
4037 produced from a single source package into separate outputs. For
4038 instance, the GLib C library (used by GTK+ and related packages)
4039 installs more than 20 MiB of reference documentation as HTML pages.
4040 To save space for users who do not need it, the documentation goes to a
4041 separate output, called @code{doc}. To install the main GLib output,
4042 which contains everything but the documentation, one would run:
4048 @cindex documentation
4049 The command to install its documentation is:
4052 guix install glib:doc
4055 Some packages install programs with different ``dependency footprints''.
4056 For instance, the WordNet package installs both command-line tools and
4057 graphical user interfaces (GUIs). The former depend solely on the C
4058 library, whereas the latter depend on Tcl/Tk and the underlying X
4059 libraries. In this case, we leave the command-line tools in the default
4060 output, whereas the GUIs are in a separate output. This allows users
4061 who do not need the GUIs to save space. The @command{guix size} command
4062 can help find out about such situations (@pxref{Invoking guix size}).
4063 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
4065 There are several such multiple-output packages in the GNU distribution.
4066 Other conventional output names include @code{lib} for libraries and
4067 possibly header files, @code{bin} for stand-alone programs, and
4068 @code{debug} for debugging information (@pxref{Installing Debugging
4069 Files}). The outputs of a packages are listed in the third column of
4070 the output of @command{guix package --list-available} (@pxref{Invoking
4074 @node Invoking guix gc
4075 @section Invoking @command{guix gc}
4077 @cindex garbage collector
4079 Packages that are installed, but not used, may be @dfn{garbage-collected}.
4080 The @command{guix gc} command allows users to explicitly run the garbage
4081 collector to reclaim space from the @file{/gnu/store} directory. It is
4082 the @emph{only} way to remove files from @file{/gnu/store}---removing
4083 files or directories manually may break it beyond repair!
4086 @cindex garbage collector roots
4087 The garbage collector has a set of known @dfn{roots}: any file under
4088 @file{/gnu/store} reachable from a root is considered @dfn{live} and
4089 cannot be deleted; any other file is considered @dfn{dead} and may be
4090 deleted. The set of garbage collector roots (``GC roots'' for short)
4091 includes default user profiles; by default, the symlinks under
4092 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
4093 added with @command{guix build --root}, for example (@pxref{Invoking
4094 guix build}). The @command{guix gc --list-roots} command lists them.
4096 Prior to running @code{guix gc --collect-garbage} to make space, it is
4097 often useful to remove old generations from user profiles; that way, old
4098 package builds referenced by those generations can be reclaimed. This
4099 is achieved by running @code{guix package --delete-generations}
4100 (@pxref{Invoking guix package}).
4102 Our recommendation is to run a garbage collection periodically, or when
4103 you are short on disk space. For instance, to guarantee that at least
4104 5@tie{}GB are available on your disk, simply run:
4110 It is perfectly safe to run as a non-interactive periodic job
4111 (@pxref{Scheduled Job Execution}, for how to set up such a job).
4112 Running @command{guix gc} with no arguments will collect as
4113 much garbage as it can, but that is often inconvenient: you may find
4114 yourself having to rebuild or re-download software that is ``dead'' from
4115 the GC viewpoint but that is necessary to build other pieces of
4116 software---e.g., the compiler tool chain.
4118 The @command{guix gc} command has three modes of operation: it can be
4119 used to garbage-collect any dead files (the default), to delete specific
4120 files (the @option{--delete} option), to print garbage-collector
4121 information, or for more advanced queries. The garbage collection
4122 options are as follows:
4125 @item --collect-garbage[=@var{min}]
4126 @itemx -C [@var{min}]
4127 Collect garbage---i.e., unreachable @file{/gnu/store} files and
4128 sub-directories. This is the default operation when no option is
4131 When @var{min} is given, stop once @var{min} bytes have been collected.
4132 @var{min} may be a number of bytes, or it may include a unit as a
4133 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
4134 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
4136 When @var{min} is omitted, collect all the garbage.
4138 @item --free-space=@var{free}
4139 @itemx -F @var{free}
4140 Collect garbage until @var{free} space is available under
4141 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
4142 as @code{500MiB}, as described above.
4144 When @var{free} or more is already available in @file{/gnu/store}, do
4145 nothing and exit immediately.
4147 @item --delete-generations[=@var{duration}]
4148 @itemx -d [@var{duration}]
4149 Before starting the garbage collection process, delete all the generations
4150 older than @var{duration}, for all the user profiles; when run as root, this
4151 applies to all the profiles @emph{of all the users}.
4153 For example, this command deletes all the generations of all your profiles
4154 that are older than 2 months (except generations that are current), and then
4155 proceeds to free space until at least 10 GiB are available:
4158 guix gc -d 2m -F 10G
4163 Attempt to delete all the store files and directories specified as
4164 arguments. This fails if some of the files are not in the store, or if
4165 they are still live.
4167 @item --list-failures
4168 List store items corresponding to cached build failures.
4170 This prints nothing unless the daemon was started with
4171 @option{--cache-failures} (@pxref{Invoking guix-daemon,
4172 @option{--cache-failures}}).
4175 List the GC roots owned by the user; when run as root, list @emph{all} the GC
4179 List store items in use by currently running processes. These store
4180 items are effectively considered GC roots: they cannot be deleted.
4182 @item --clear-failures
4183 Remove the specified store items from the failed-build cache.
4185 Again, this option only makes sense when the daemon is started with
4186 @option{--cache-failures}. Otherwise, it does nothing.
4189 Show the list of dead files and directories still present in the
4190 store---i.e., files and directories no longer reachable from any root.
4193 Show the list of live store files and directories.
4197 In addition, the references among existing store files can be queried:
4203 @cindex package dependencies
4204 List the references (respectively, the referrers) of store files given
4210 List the requisites of the store files passed as arguments. Requisites
4211 include the store files themselves, their references, and the references
4212 of these, recursively. In other words, the returned list is the
4213 @dfn{transitive closure} of the store files.
4215 @xref{Invoking guix size}, for a tool to profile the size of the closure
4216 of an element. @xref{Invoking guix graph}, for a tool to visualize
4217 the graph of references.
4221 Return the derivation(s) leading to the given store items
4222 (@pxref{Derivations}).
4224 For example, this command:
4227 guix gc --derivers $(guix package -I ^emacs$ | cut -f4)
4231 returns the @file{.drv} file(s) leading to the @code{emacs} package
4232 installed in your profile.
4234 Note that there may be zero matching @file{.drv} files, for instance
4235 because these files have been garbage-collected. There can also be more
4236 than one matching @file{.drv} due to fixed-output derivations.
4239 Lastly, the following options allow you to check the integrity of the
4240 store and to control disk usage.
4244 @item --verify[=@var{options}]
4245 @cindex integrity, of the store
4246 @cindex integrity checking
4247 Verify the integrity of the store.
4249 By default, make sure that all the store items marked as valid in the
4250 database of the daemon actually exist in @file{/gnu/store}.
4252 When provided, @var{options} must be a comma-separated list containing one
4253 or more of @code{contents} and @code{repair}.
4255 When passing @option{--verify=contents}, the daemon computes the
4256 content hash of each store item and compares it against its hash in the
4257 database. Hash mismatches are reported as data corruptions. Because it
4258 traverses @emph{all the files in the store}, this command can take a
4259 long time, especially on systems with a slow disk drive.
4261 @cindex repairing the store
4262 @cindex corruption, recovering from
4263 Using @option{--verify=repair} or @option{--verify=contents,repair}
4264 causes the daemon to try to repair corrupt store items by fetching
4265 substitutes for them (@pxref{Substitutes}). Because repairing is not
4266 atomic, and thus potentially dangerous, it is available only to the
4267 system administrator. A lightweight alternative, when you know exactly
4268 which items in the store are corrupt, is @command{guix build --repair}
4269 (@pxref{Invoking guix build}).
4272 @cindex deduplication
4273 Optimize the store by hard-linking identical files---this is
4274 @dfn{deduplication}.
4276 The daemon performs deduplication after each successful build or archive
4277 import, unless it was started with @option{--disable-deduplication}
4278 (@pxref{Invoking guix-daemon, @option{--disable-deduplication}}). Thus,
4279 this option is primarily useful when the daemon was running with
4280 @option{--disable-deduplication}.
4284 @node Invoking guix pull
4285 @section Invoking @command{guix pull}
4287 @cindex upgrading Guix
4288 @cindex updating Guix
4289 @cindex @command{guix pull}
4291 @cindex security, @command{guix pull}
4292 @cindex authenticity, of code obtained with @command{guix pull}
4293 Packages are installed or upgraded to the latest version available in
4294 the distribution currently available on your local machine. To update
4295 that distribution, along with the Guix tools, you must run @command{guix
4296 pull}: the command downloads the latest Guix source code and package
4297 descriptions, and deploys it. Source code is downloaded from a
4298 @uref{https://git-scm.com, Git} repository, by default the official
4299 GNU@tie{}Guix repository, though this can be customized. @command{guix
4300 pull} ensures that the code it downloads is @emph{authentic} by
4301 verifying that commits are signed by Guix developers.
4303 Specifically, @command{guix pull} downloads code from the @dfn{channels}
4304 (@pxref{Channels}) specified by one of the followings, in this order:
4308 the @option{--channels} option;
4310 the user's @file{~/.config/guix/channels.scm} file;
4312 the system-wide @file{/etc/guix/channels.scm} file;
4314 the built-in default channels specified in the @code{%default-channels}
4318 On completion, @command{guix package} will use packages and package
4319 versions from this just-retrieved copy of Guix. Not only that, but all
4320 the Guix commands and Scheme modules will also be taken from that latest
4321 version. New @command{guix} sub-commands added by the update also
4324 Any user can update their Guix copy using @command{guix pull}, and the
4325 effect is limited to the user who ran @command{guix pull}. For
4326 instance, when user @code{root} runs @command{guix pull}, this has no
4327 effect on the version of Guix that user @code{alice} sees, and vice
4330 The result of running @command{guix pull} is a @dfn{profile} available
4331 under @file{~/.config/guix/current} containing the latest Guix. Thus,
4332 make sure to add it to the beginning of your search path so that you use
4333 the latest version, and similarly for the Info manual
4334 (@pxref{Documentation}):
4337 export PATH="$HOME/.config/guix/current/bin:$PATH"
4338 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
4341 The @option{--list-generations} or @option{-l} option lists past generations
4342 produced by @command{guix pull}, along with details about their provenance:
4346 Generation 1 Jun 10 2018 00:18:18
4348 repository URL: https://git.savannah.gnu.org/git/guix.git
4349 branch: origin/master
4350 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
4352 Generation 2 Jun 11 2018 11:02:49
4354 repository URL: https://git.savannah.gnu.org/git/guix.git
4355 branch: origin/master
4356 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
4357 2 new packages: keepalived, libnfnetlink
4358 6 packages upgraded: emacs-nix-mode@@2.0.4,
4359 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
4360 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
4362 Generation 3 Jun 13 2018 23:31:07 (current)
4364 repository URL: https://git.savannah.gnu.org/git/guix.git
4365 branch: origin/master
4366 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
4367 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
4368 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
4371 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
4372 describe the current status of Guix.
4374 This @code{~/.config/guix/current} profile works exactly like the profiles
4375 created by @command{guix package} (@pxref{Invoking guix package}). That
4376 is, you can list generations, roll back to the previous
4377 generation---i.e., the previous Guix---and so on:
4380 $ guix pull --roll-back
4381 switched from generation 3 to 2
4382 $ guix pull --delete-generations=1
4383 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
4386 You can also use @command{guix package} (@pxref{Invoking guix package})
4387 to manage the profile by naming it explicitly:
4389 $ guix package -p ~/.config/guix/current --roll-back
4390 switched from generation 3 to 2
4391 $ guix package -p ~/.config/guix/current --delete-generations=1
4392 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
4395 The @command{guix pull} command is usually invoked with no arguments,
4396 but it supports the following options:
4399 @item --url=@var{url}
4400 @itemx --commit=@var{commit}
4401 @itemx --branch=@var{branch}
4402 Download code for the @code{guix} channel from the specified @var{url}, at the
4403 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4404 string), or @var{branch}.
4406 @cindex @file{channels.scm}, configuration file
4407 @cindex configuration file for channels
4408 These options are provided for convenience, but you can also specify your
4409 configuration in the @file{~/.config/guix/channels.scm} file or using the
4410 @option{--channels} option (see below).
4412 @item --channels=@var{file}
4413 @itemx -C @var{file}
4414 Read the list of channels from @var{file} instead of
4415 @file{~/.config/guix/channels.scm} or @file{/etc/guix/channels.scm}.
4416 @var{file} must contain Scheme code that
4417 evaluates to a list of channel objects. @xref{Channels}, for more
4420 @cindex channel news
4423 Display the list of packages added or upgraded since the previous
4424 generation, as well as, occasionally, news written by channel authors
4425 for their users (@pxref{Channels, Writing Channel News}).
4427 The package information is the same as displayed upon @command{guix
4428 pull} completion, but without ellipses; it is also similar to the output
4429 of @command{guix pull -l} for the last generation (see below).
4431 @item --list-generations[=@var{pattern}]
4432 @itemx -l [@var{pattern}]
4433 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
4434 is provided, the subset of generations that match @var{pattern}.
4435 The syntax of @var{pattern} is the same as with @code{guix package
4436 --list-generations} (@pxref{Invoking guix package}).
4439 @cindex rolling back
4440 @cindex undoing transactions
4441 @cindex transactions, undoing
4442 Roll back to the previous @dfn{generation} of @file{~/.config/guix/current}---i.e.,
4443 undo the last transaction.
4445 @item --switch-generation=@var{pattern}
4446 @itemx -S @var{pattern}
4448 Switch to a particular generation defined by @var{pattern}.
4450 @var{pattern} may be either a generation number or a number prefixed
4451 with ``+'' or ``-''. The latter means: move forward/backward by a
4452 specified number of generations. For example, if you want to return to
4453 the latest generation after @option{--roll-back}, use
4454 @option{--switch-generation=+1}.
4456 @item --delete-generations[=@var{pattern}]
4457 @itemx -d [@var{pattern}]
4458 When @var{pattern} is omitted, delete all generations except the current
4461 This command accepts the same patterns as @option{--list-generations}.
4462 When @var{pattern} is specified, delete the matching generations. When
4463 @var{pattern} specifies a duration, generations @emph{older} than the
4464 specified duration match. For instance, @option{--delete-generations=1m}
4465 deletes generations that are more than one month old.
4467 If the current generation matches, it is @emph{not} deleted.
4469 Note that deleting generations prevents rolling back to them.
4470 Consequently, this command must be used with care.
4472 @xref{Invoking guix describe}, for a way to display information about the
4473 current generation only.
4475 @item --profile=@var{profile}
4476 @itemx -p @var{profile}
4477 Use @var{profile} instead of @file{~/.config/guix/current}.
4481 Show which channel commit(s) would be used and what would be built or
4482 substituted but do not actually do it.
4484 @item --allow-downgrades
4485 Allow pulling older or unrelated revisions of channels than those
4488 @cindex downgrade attacks, protection against
4489 By default, @command{guix pull} protects against so-called ``downgrade
4490 attacks'' whereby the Git repository of a channel would be reset to an
4491 earlier or unrelated revision of itself, potentially leading you to
4492 install older, known-vulnerable versions of software packages.
4495 Make sure you understand its security implications before using
4496 @option{--allow-downgrades}.
4499 @item --disable-authentication
4500 Allow pulling channel code without authenticating it.
4502 @cindex authentication, of channel code
4503 By default, @command{guix pull} authenticates code downloaded from
4504 channels by verifying that its commits are signed by authorized
4505 developers, and raises an error if this is not the case. This option
4506 instructs it to not perform any such verification.
4509 Make sure you understand its security implications before using
4510 @option{--disable-authentication}.
4513 @item --system=@var{system}
4514 @itemx -s @var{system}
4515 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
4516 the system type of the build host.
4519 Use the bootstrap Guile to build the latest Guix. This option is only
4520 useful to Guix developers.
4523 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
4524 repository and branch to pull from, as well as @emph{additional} repositories
4525 containing package modules that should be deployed. @xref{Channels}, for more
4528 In addition, @command{guix pull} supports all the common build options
4529 (@pxref{Common Build Options}).
4531 @node Invoking guix time-machine
4532 @section Invoking @command{guix time-machine}
4534 @cindex @command{guix time-machine}
4535 @cindex pinning, channels
4536 @cindex replicating Guix
4537 @cindex reproducibility, of Guix
4539 The @command{guix time-machine} command provides access to other
4540 revisions of Guix, for example to install older versions of packages,
4541 or to reproduce a computation in an identical environment. The revision
4542 of Guix to be used is defined by a commit or by a channel
4543 description file created by @command{guix describe}
4544 (@pxref{Invoking guix describe}).
4546 The general syntax is:
4549 guix time-machine @var{options}@dots{} -- @var{command} @var {arg}@dots{}
4552 where @var{command} and @var{arg}@dots{} are passed unmodified to the
4553 @command{guix} command of the specified revision. The @var{options} that define
4554 this revision are the same as for @command{guix pull} (@pxref{Invoking guix pull}):
4557 @item --url=@var{url}
4558 @itemx --commit=@var{commit}
4559 @itemx --branch=@var{branch}
4560 Use the @code{guix} channel from the specified @var{url}, at the
4561 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4562 string), or @var{branch}.
4564 @item --channels=@var{file}
4565 @itemx -C @var{file}
4566 Read the list of channels from @var{file}. @var{file} must contain
4567 Scheme code that evaluates to a list of channel objects.
4568 @xref{Channels} for more information.
4571 As for @command{guix pull}, the absence of any options means that the
4572 latest commit on the master branch will be used. The command
4575 guix time-machine -- build hello
4578 will thus build the package @code{hello} as defined in the master branch,
4579 which is in general a newer revision of Guix than you have installed.
4580 Time travel works in both directions!
4582 Note that @command{guix time-machine} can trigger builds of channels and
4583 their dependencies, and these are controlled by the standard build
4584 options (@pxref{Common Build Options}).
4589 @c TODO: Remove this once we're more confident about API stability.
4591 The functionality described here is a ``technology preview'' as of version
4592 @value{VERSION}. As such, the interface is subject to change.
4596 @cindex composition of Guix revisions
4597 Sometimes you might need to mix packages from the revision of Guix you're
4598 currently running with packages available in a different revision of Guix.
4599 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
4600 revisions in arbitrary ways.
4602 @cindex inferior packages
4603 Technically, an ``inferior'' is essentially a separate Guix process connected
4604 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
4605 @code{(guix inferior)} module allows you to create inferiors and to
4606 communicate with them. It also provides a high-level interface to browse and
4607 manipulate the packages that an inferior provides---@dfn{inferior packages}.
4609 When combined with channels (@pxref{Channels}), inferiors provide a simple way
4610 to interact with a separate revision of Guix. For example, let's assume you
4611 want to install in your profile the current @code{guile} package, along with
4612 the @code{guile-json} as it existed in an older revision of Guix---perhaps
4613 because the newer @code{guile-json} has an incompatible API and you want to
4614 run your code against the old API@. To do that, you could write a manifest for
4615 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
4616 manifest, you would create an inferior for that old Guix revision you care
4617 about, and you would look up the @code{guile-json} package in the inferior:
4620 (use-modules (guix inferior) (guix channels)
4621 (srfi srfi-1)) ;for 'first'
4624 ;; This is the old revision from which we want to
4625 ;; extract guile-json.
4628 (url "https://git.savannah.gnu.org/git/guix.git")
4630 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
4633 ;; An inferior representing the above revision.
4634 (inferior-for-channels channels))
4636 ;; Now create a manifest with the current "guile" package
4637 ;; and the old "guile-json" package.
4639 (list (first (lookup-inferior-packages inferior "guile-json"))
4640 (specification->package "guile")))
4643 On its first run, @command{guix package --manifest} might have to build the
4644 channel you specified before it can create the inferior; subsequent runs will
4645 be much faster because the Guix revision will be cached.
4647 The @code{(guix inferior)} module provides the following procedures to open an
4650 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
4651 [#:cache-directory] [#:ttl]
4652 Return an inferior for @var{channels}, a list of channels. Use the cache at
4653 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4654 This procedure opens a new connection to the build daemon.
4656 As a side effect, this procedure may build or substitute binaries for
4657 @var{channels}, which can take time.
4660 @deffn {Scheme Procedure} open-inferior @var{directory} @
4661 [#:command "bin/guix"]
4662 Open the inferior Guix in @var{directory}, running
4663 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4664 the inferior could not be launched.
4667 @cindex inferior packages
4668 The procedures listed below allow you to obtain and manipulate inferior
4671 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4672 Return the list of packages known to @var{inferior}.
4675 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4677 Return the sorted list of inferior packages matching @var{name} in
4678 @var{inferior}, with highest version numbers first. If @var{version} is true,
4679 return only packages with a version number prefixed by @var{version}.
4682 @deffn {Scheme Procedure} inferior-package? @var{obj}
4683 Return true if @var{obj} is an inferior package.
4686 @deffn {Scheme Procedure} inferior-package-name @var{package}
4687 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4688 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4689 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4690 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4691 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4692 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4693 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4694 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4695 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4696 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4697 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4698 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4699 These procedures are the counterpart of package record accessors
4700 (@pxref{package Reference}). Most of them work by querying the inferior
4701 @var{package} comes from, so the inferior must still be live when you call
4705 Inferior packages can be used transparently like any other package or
4706 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4707 transparently handled by the @code{packages->manifest} procedure, which is
4708 commonly used in manifests (@pxref{Invoking guix package, the
4709 @option{--manifest} option of @command{guix package}}). Thus you can insert
4710 an inferior package pretty much anywhere you would insert a regular package:
4711 in manifests, in the @code{packages} field of your @code{operating-system}
4712 declaration, and so on.
4714 @node Invoking guix describe
4715 @section Invoking @command{guix describe}
4717 @cindex reproducibility
4718 @cindex replicating Guix
4719 Often you may want to answer questions like: ``Which revision of Guix am I
4720 using?'' or ``Which channels am I using?'' This is useful information in many
4721 situations: if you want to @emph{replicate} an environment on a different
4722 machine or user account, if you want to report a bug or to determine what
4723 change in the channels you are using caused it, or if you want to record your
4724 system state for reproducibility purposes. The @command{guix describe}
4725 command answers these questions.
4727 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4728 displays the channel(s) that it was built from, including their repository URL
4729 and commit IDs (@pxref{Channels}):
4733 Generation 10 Sep 03 2018 17:32:44 (current)
4735 repository URL: https://git.savannah.gnu.org/git/guix.git
4737 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4740 If you're familiar with the Git version control system, this is similar in
4741 spirit to @command{git describe}; the output is also similar to that of
4742 @command{guix pull --list-generations}, but limited to the current generation
4743 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4744 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4745 information is all it takes to describe the revision of Guix you're using, and
4746 also to replicate it.
4748 To make it easier to replicate Guix, @command{guix describe} can also be asked
4749 to return a list of channels instead of the human-readable description above:
4752 $ guix describe -f channels
4755 (url "https://git.savannah.gnu.org/git/guix.git")
4757 "e0fa68c7718fffd33d81af415279d6ddb518f727")
4759 (make-channel-introduction
4760 "9edb3f66fd807b096b48283debdcddccfea34bad"
4761 (openpgp-fingerprint
4762 "BBB0 2DDF 2CEA F6A8 0D1D E643 A2A0 6DF2 A33A 54FA")))))
4766 You can save this to a file and feed it to @command{guix pull -C} on some
4767 other machine or at a later point in time, which will instantiate @emph{this
4768 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4769 From there on, since you're able to deploy the same revision of Guix, you can
4770 just as well @emph{replicate a complete software environment}. We humbly
4771 think that this is @emph{awesome}, and we hope you'll like it too!
4773 The details of the options supported by @command{guix describe} are as
4777 @item --format=@var{format}
4778 @itemx -f @var{format}
4779 Produce output in the specified @var{format}, one of:
4783 produce human-readable output;
4785 produce a list of channel specifications that can be passed to @command{guix
4786 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4788 @item channels-sans-intro
4789 like @code{channels}, but omit the @code{introduction} field; use it to
4790 produce a channel specification suitable for Guix version 1.1.0 or
4791 earlier---the @code{introduction} field has to do with channel
4792 authentication (@pxref{Channels, Channel Authentication}) and is not
4793 supported by these older versions;
4796 produce a list of channel specifications in JSON format;
4798 produce a list of channel specifications in Recutils format.
4801 @item --list-formats
4802 Display available formats for @option{--format} option.
4804 @item --profile=@var{profile}
4805 @itemx -p @var{profile}
4806 Display information about @var{profile}.
4809 @node Invoking guix archive
4810 @section Invoking @command{guix archive}
4812 @cindex @command{guix archive}
4814 The @command{guix archive} command allows users to @dfn{export} files
4815 from the store into a single archive, and to later @dfn{import} them on
4816 a machine that runs Guix.
4817 In particular, it allows store files to be transferred from one machine
4818 to the store on another machine.
4821 If you're looking for a way to produce archives in a format suitable for
4822 tools other than Guix, @pxref{Invoking guix pack}.
4825 @cindex exporting store items
4826 To export store files as an archive to standard output, run:
4829 guix archive --export @var{options} @var{specifications}...
4832 @var{specifications} may be either store file names or package
4833 specifications, as for @command{guix package} (@pxref{Invoking guix
4834 package}). For instance, the following command creates an archive
4835 containing the @code{gui} output of the @code{git} package and the main
4836 output of @code{emacs}:
4839 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4842 If the specified packages are not built yet, @command{guix archive}
4843 automatically builds them. The build process may be controlled with the
4844 common build options (@pxref{Common Build Options}).
4846 To transfer the @code{emacs} package to a machine connected over SSH,
4850 guix archive --export -r emacs | ssh the-machine guix archive --import
4854 Similarly, a complete user profile may be transferred from one machine
4855 to another like this:
4858 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4859 ssh the-machine guix archive --import
4863 However, note that, in both examples, all of @code{emacs} and the
4864 profile as well as all of their dependencies are transferred (due to
4865 @option{-r}), regardless of what is already available in the store on
4866 the target machine. The @option{--missing} option can help figure out
4867 which items are missing from the target store. The @command{guix copy}
4868 command simplifies and optimizes this whole process, so this is probably
4869 what you should use in this case (@pxref{Invoking guix copy}).
4871 @cindex nar, archive format
4872 @cindex normalized archive (nar)
4873 @cindex nar bundle, archive format
4874 Each store item is written in the @dfn{normalized archive} or @dfn{nar}
4875 format (described below), and the output of @command{guix archive
4876 --export} (and input of @command{guix archive --import}) is a @dfn{nar
4880 comparable in spirit to `tar', but with differences
4881 that make it more appropriate for our purposes. First, rather than
4882 recording all Unix metadata for each file, the nar format only mentions
4883 the file type (regular, directory, or symbolic link); Unix permissions
4884 and owner/group are dismissed. Second, the order in which directory
4885 entries are stored always follows the order of file names according to
4886 the C locale collation order. This makes archive production fully
4889 That nar bundle format is essentially the concatenation of zero or more
4890 nars along with metadata for each store item it contains: its file name,
4891 references, corresponding derivation, and a digital signature.
4893 When exporting, the daemon digitally signs the contents of the archive,
4894 and that digital signature is appended. When importing, the daemon
4895 verifies the signature and rejects the import in case of an invalid
4896 signature or if the signing key is not authorized.
4897 @c FIXME: Add xref to daemon doc about signatures.
4899 The main options are:
4903 Export the specified store files or packages (see below). Write the
4904 resulting archive to the standard output.
4906 Dependencies are @emph{not} included in the output, unless
4907 @option{--recursive} is passed.
4911 When combined with @option{--export}, this instructs @command{guix archive}
4912 to include dependencies of the given items in the archive. Thus, the
4913 resulting archive is self-contained: it contains the closure of the
4914 exported store items.
4917 Read an archive from the standard input, and import the files listed
4918 therein into the store. Abort if the archive has an invalid digital
4919 signature, or if it is signed by a public key not among the authorized
4920 keys (see @option{--authorize} below).
4923 Read a list of store file names from the standard input, one per line,
4924 and write on the standard output the subset of these files missing from
4927 @item --generate-key[=@var{parameters}]
4928 @cindex signing, archives
4929 Generate a new key pair for the daemon. This is a prerequisite before
4930 archives can be exported with @option{--export}. This
4931 operation is usually instantaneous but it can take time if the system's
4932 entropy pool needs to be refilled. On Guix System,
4933 @code{guix-service-type} takes care of generating this key pair the
4936 The generated key pair is typically stored under @file{/etc/guix}, in
4937 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
4938 key, which must be kept secret). When @var{parameters} is omitted,
4939 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
4940 versions before 1.6.0, it is a 4096-bit RSA key.
4941 Alternatively, @var{parameters} can specify
4942 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
4943 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
4944 Libgcrypt Reference Manual}).
4947 @cindex authorizing, archives
4948 Authorize imports signed by the public key passed on standard input.
4949 The public key must be in ``s-expression advanced format''---i.e., the
4950 same format as the @file{signing-key.pub} file.
4952 The list of authorized keys is kept in the human-editable file
4953 @file{/etc/guix/acl}. The file contains
4954 @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
4955 s-expressions''} and is structured as an access-control list in the
4956 @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
4959 @item --extract=@var{directory}
4960 @itemx -x @var{directory}
4961 Read a single-item archive as served by substitute servers
4962 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
4963 low-level operation needed in only very narrow use cases; see below.
4965 For example, the following command extracts the substitute for Emacs
4966 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
4970 https://@value{SUBSTITUTE-SERVER}/nar/gzip/@dots{}-emacs-24.5 \
4971 | gunzip | guix archive -x /tmp/emacs
4974 Single-item archives are different from multiple-item archives produced
4975 by @command{guix archive --export}; they contain a single store item,
4976 and they do @emph{not} embed a signature. Thus this operation does
4977 @emph{no} signature verification and its output should be considered
4980 The primary purpose of this operation is to facilitate inspection of
4981 archive contents coming from possibly untrusted substitute servers
4982 (@pxref{Invoking guix challenge}).
4986 Read a single-item archive as served by substitute servers
4987 (@pxref{Substitutes}) and print the list of files it contains, as in
4992 https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-emacs-26.3 \
4993 | lzip -d | guix archive -t
4998 @c *********************************************************************
5003 @cindex @file{channels.scm}, configuration file
5004 @cindex configuration file for channels
5005 @cindex @command{guix pull}, configuration file
5006 @cindex configuration of @command{guix pull}
5007 Guix and its package collection are updated by running @command{guix pull}
5008 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
5009 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
5010 customized by defining @dfn{channels} in the
5011 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
5012 of a Git repository to be deployed, and @command{guix pull} can be instructed
5013 to pull from one or more channels. In other words, channels can be used
5014 to @emph{customize} and to @emph{extend} Guix, as we will see below.
5015 Guix is able to take into account security concerns and deal with authenticated
5019 * Specifying Additional Channels:: Extending the package collection.
5020 * Using a Custom Guix Channel:: Using a customized Guix.
5021 * Replicating Guix:: Running the @emph{exact same} Guix.
5022 * Channel Authentication:: How Guix verifies what it fetches.
5023 * Channels with Substitutes:: Using channels with available substitutes.
5024 * Creating a Channel:: How to write your custom channel.
5025 * Package Modules in a Sub-directory:: Specifying the channel's package modules location.
5026 * Declaring Channel Dependencies:: How to depend on other channels.
5027 * Specifying Channel Authorizations:: Defining channel authors authorizations.
5028 * Primary URL:: Distinguishing mirror to original.
5029 * Writing Channel News:: Communicating information to channel's users.
5032 @node Specifying Additional Channels
5033 @section Specifying Additional Channels
5035 @cindex extending the package collection (channels)
5036 @cindex variant packages (channels)
5037 You can specify @emph{additional channels} to pull from. To use a channel, write
5038 @code{~/.config/guix/channels.scm} to instruct @command{guix pull} to pull from it
5039 @emph{in addition} to the default Guix channel(s):
5041 @vindex %default-channels
5043 ;; Add variant packages to those Guix provides.
5045 (name 'variant-packages)
5046 (url "https://example.org/variant-packages.git"))
5051 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
5052 add a channel the list of channels that the variable @code{%default-channels}
5053 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
5054 Manual}). With this file in place, @command{guix pull} builds not only Guix
5055 but also the package modules from your own repository. The result in
5056 @file{~/.config/guix/current} is the union of Guix with your own package
5060 $ guix pull --list-generations
5062 Generation 19 Aug 27 2018 16:20:48
5064 repository URL: https://git.savannah.gnu.org/git/guix.git
5066 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
5067 variant-packages dd3df5e
5068 repository URL: https://example.org/variant-packages.git
5070 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
5071 11 new packages: variant-gimp, variant-emacs-with-cool-features, @dots{}
5072 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
5076 The output of @command{guix pull} above shows that Generation@tie{}19 includes
5077 both Guix and packages from the @code{variant-personal-packages} channel. Among
5078 the new and upgraded packages that are listed, some like @code{variant-gimp} and
5079 @code{variant-emacs-with-cool-features} might come from
5080 @code{variant-packages}, while others come from the Guix default channel.
5082 @node Using a Custom Guix Channel
5083 @section Using a Custom Guix Channel
5085 The channel called @code{guix} specifies where Guix itself---its command-line
5086 tools as well as its package collection---should be downloaded. For instance,
5087 suppose you want to update from another copy of the Guix repository at
5088 @code{example.org}, and specifically the @code{super-hacks} branch, you can
5089 write in @code{~/.config/guix/channels.scm} this specification:
5092 ;; Tell 'guix pull' to use another repo.
5095 (url "https://example.org/another-guix.git")
5096 (branch "super-hacks")))
5100 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
5101 branch of the repository at @code{example.org}. The authentication concern is
5102 addressed below ((@pxref{Channel Authentication}).
5104 @node Replicating Guix
5105 @section Replicating Guix
5107 @cindex pinning, channels
5108 @cindex replicating Guix
5109 @cindex reproducibility, of Guix
5110 The @command{guix pull --list-generations} output above shows precisely which
5111 commits were used to build this instance of Guix. We can thus replicate it,
5112 say, on another machine, by providing a channel specification in
5113 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
5116 ;; Deploy specific commits of my channels of interest.
5119 (url "https://git.savannah.gnu.org/git/guix.git")
5120 (commit "6298c3ffd9654d3231a6f25390b056483e8f407c"))
5122 (name 'variant-packages)
5123 (url "https://example.org/variant-packages.git")
5124 (commit "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
5127 The @command{guix describe --format=channels} command can even generate this
5128 list of channels directly (@pxref{Invoking guix describe}). The resulting
5129 file can be used with the -C options of @command{guix pull}
5130 (@pxref{Invoking guix pull}) or @command{guix time-machine}
5131 (@pxref{Invoking guix time-machine}).
5133 At this point the two machines run the @emph{exact same Guix}, with access to
5134 the @emph{exact same packages}. The output of @command{guix build gimp} on
5135 one machine will be exactly the same, bit for bit, as the output of the same
5136 command on the other machine. It also means both machines have access to all
5137 the source code of Guix and, transitively, to all the source code of every
5140 This gives you super powers, allowing you to track the provenance of binary
5141 artifacts with very fine grain, and to reproduce software environments at
5142 will---some sort of ``meta reproducibility'' capabilities, if you will.
5143 @xref{Inferiors}, for another way to take advantage of these super powers.
5145 @node Channel Authentication
5146 @section Channel Authentication
5148 @anchor{channel-authentication}
5149 @cindex authentication, of channel code
5150 The @command{guix pull} and @command{guix time-machine} commands
5151 @dfn{authenticate} the code retrieved from channels: they make sure each
5152 commit that is fetched is signed by an authorized developer. The goal
5153 is to protect from unauthorized modifications to the channel that would
5154 lead users to run malicious code.
5156 As a user, you must provide a @dfn{channel introduction} in your
5157 channels file so that Guix knows how to authenticate its first commit.
5158 A channel specification, including its introduction, looks something
5163 (name 'some-channel)
5164 (url "https://example.org/some-channel.git")
5166 (make-channel-introduction
5167 "6f0d8cc0d88abb59c324b2990bfee2876016bb86"
5168 (openpgp-fingerprint
5169 "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
5172 The specification above shows the name and URL of the channel. The call
5173 to @code{make-channel-introduction} above specifies that authentication
5174 of this channel starts at commit @code{6f0d8cc@dots{}}, which is signed
5175 by the OpenPGP key with fingerprint @code{CABB A931@dots{}}.
5177 For the main channel, called @code{guix}, you automatically get that
5178 information from your Guix installation. For other channels, include
5179 the channel introduction provided by the channel authors in your
5180 @file{channels.scm} file. Make sure you retrieve the channel
5181 introduction from a trusted source since that is the root of your trust.
5183 If you're curious about the authentication mechanics, read on!
5185 @node Channels with Substitutes
5186 @section Channels with Substitutes
5188 When running @command{guix pull}, Guix will first compile the
5189 definitions of every available package. This is an expensive operation
5190 for which substitutes (@pxref{Substitutes}) may be available. The
5191 following snippet in @file{channels.scm} will ensure that @command{guix
5192 pull} uses the latest commit with available substitutes for the package
5193 definitions: this is done by querying the continuous integration
5194 server at @url{https://ci.guix.gnu.org}.
5197 (use-modules (guix ci))
5199 (list (channel-with-substitutes-available
5200 %default-guix-channel
5201 "https://ci.guix.gnu.org"))
5204 Note that this does not mean that all the packages that you will
5205 install after running @command{guix pull} will have available
5206 substitutes. It only ensures that @command{guix pull} will not try to
5207 compile package definitions. This is particularly useful when using
5208 machines with limited resources.
5210 @node Creating a Channel
5211 @section Creating a Channel
5213 @cindex personal packages (channels)
5214 @cindex channels, for personal packages
5215 Let's say you have a bunch of custom package variants or personal packages
5216 that you think would make little sense to contribute to the Guix project, but
5217 would like to have these packages transparently available to you at the
5218 command line. You would first write modules containing those package
5219 definitions (@pxref{Package Modules}), maintain them in a Git repository, and
5220 then you and anyone else can use it as an additional channel to get packages
5223 @c What follows stems from discussions at
5224 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
5225 @c earlier discussions on guix-devel@gnu.org.
5227 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
5228 publish your personal channel to the world, we would like to share a few words
5233 Before publishing a channel, please consider contributing your package
5234 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
5235 to free software of all sorts, and packages in Guix proper are readily
5236 available to all Guix users and benefit from the project's quality assurance
5240 When you maintain package definitions outside Guix, we, Guix developers,
5241 consider that @emph{the compatibility burden is on you}. Remember that
5242 package modules and package definitions are just Scheme code that uses various
5243 programming interfaces (APIs). We want to remain free to change these APIs to
5244 keep improving Guix, possibly in ways that break your channel. We never
5245 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
5249 Corollary: if you're using an external channel and that channel breaks, please
5250 @emph{report the issue to the channel authors}, not to the Guix project.
5253 You've been warned! Having said this, we believe external channels are a
5254 practical way to exert your freedom to augment Guix' package collection and to
5255 share your improvements, which are basic tenets of
5256 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
5257 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
5260 To create a channel, create a Git repository containing your own package
5261 modules and make it available. The repository can contain anything, but a
5262 useful channel will contain Guile modules that export packages. Once you
5263 start using a channel, Guix will behave as if the root directory of that
5264 channel's Git repository has been added to the Guile load path (@pxref{Load
5265 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
5266 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
5267 module, then the module will be available under the name @code{(my-packages
5268 my-tools)}, and you will be able to use it like any other module
5269 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
5271 As a channel author, consider bundling authentication material with your
5272 channel so that users can authenticate it. @xref{Channel
5273 Authentication}, and @ref{Specifying Channel Authorizations}, for info
5277 @node Package Modules in a Sub-directory
5278 @section Package Modules in a Sub-directory
5280 @cindex subdirectory, channels
5281 As a channel author, you may want to keep your channel modules in a
5282 sub-directory. If your modules are in the sub-directory @file{guix}, you must
5283 add a meta-data file @file{.guix-channel} that contains:
5291 @node Declaring Channel Dependencies
5292 @section Declaring Channel Dependencies
5294 @cindex dependencies, channels
5295 @cindex meta-data, channels
5296 Channel authors may decide to augment a package collection provided by other
5297 channels. They can declare their channel to be dependent on other channels in
5298 a meta-data file @file{.guix-channel}, which is to be placed in the root of
5299 the channel repository.
5301 The meta-data file should contain a simple S-expression like this:
5308 (name some-collection)
5309 (url "https://example.org/first-collection.git")
5311 ;; The 'introduction' bit below is optional: you would
5312 ;; provide it for dependencies that can be authenticated.
5314 (channel-introduction
5316 (commit "a8883b58dc82e167c96506cf05095f37c2c2c6cd")
5317 (signer "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
5319 (name some-other-collection)
5320 (url "https://example.org/second-collection.git")
5321 (branch "testing"))))
5324 In the above example this channel is declared to depend on two other channels,
5325 which will both be fetched automatically. The modules provided by the channel
5326 will be compiled in an environment where the modules of all these declared
5327 channels are available.
5329 For the sake of reliability and maintainability, you should avoid dependencies
5330 on channels that you don't control, and you should aim to keep the number of
5331 dependencies to a minimum.
5333 @node Specifying Channel Authorizations
5334 @section Specifying Channel Authorizations
5336 @cindex channel authorizations
5337 @anchor{channel-authorizations}
5338 As we saw above, Guix ensures the source code it pulls from channels
5339 comes from authorized developers. As a channel author, you need to
5340 specify the list of authorized developers in the
5341 @file{.guix-authorizations} file in the channel's Git repository. The
5342 authentication rule is simple: each commit must be signed by a key
5343 listed in the @file{.guix-authorizations} file of its parent
5344 commit(s)@footnote{Git commits form a @dfn{directed acyclic graph}
5345 (DAG). Each commit can have zero or more parents; ``regular'' commits
5346 have one parent and merge commits have two parent commits. Read
5347 @uref{https://eagain.net/articles/git-for-computer-scientists/, @i{Git
5348 for Computer Scientists}} for a great overview.} The
5349 @file{.guix-authorizations} file looks like this:
5352 ;; Example '.guix-authorizations' file.
5355 (version 0) ;current file format version
5357 (("AD17 A21E F8AE D8F1 CC02 DBD9 F8AE D8F1 765C 61E3"
5359 ("2A39 3FFF 68F4 EF7A 3D29 12AF 68F4 EF7A 22FB B2D5"
5361 ("CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"
5365 Each fingerprint is followed by optional key/value pairs, as in the
5366 example above. Currently these key/value pairs are ignored.
5368 This authentication rule creates a chicken-and-egg issue: how do we
5369 authenticate the first commit? Related to that: how do we deal with
5370 channels whose repository history contains unsigned commits and lack
5371 @file{.guix-authorizations}? And how do we fork existing channels?
5373 @cindex channel introduction
5374 Channel introductions answer these questions by describing the first
5375 commit of a channel that should be authenticated. The first time a
5376 channel is fetched with @command{guix pull} or @command{guix
5377 time-machine}, the command looks up the introductory commit and verifies
5378 that it is signed by the specified OpenPGP key. From then on, it
5379 authenticates commits according to the rule above.
5381 Additionally, your channel must provide all the OpenPGP keys that were
5382 ever mentioned in @file{.guix-authorizations}, stored as @file{.key}
5383 files, which can be either binary or ``ASCII-armored''. By default,
5384 those @file{.key} files are searched for in the branch named
5385 @code{keyring} but you can specify a different branch name in
5386 @code{.guix-channel} like so:
5391 (keyring-reference "my-keyring-branch"))
5394 To summarize, as the author of a channel, there are three things you have
5395 to do to allow users to authenticate your code:
5399 Export the OpenPGP keys of past and present committers with @command{gpg
5400 --export} and store them in @file{.key} files, by default in a branch
5401 named @code{keyring} (we recommend making it an @dfn{orphan branch}).
5404 Introduce an initial @file{.guix-authorizations} in the channel's
5405 repository. Do that in a signed commit (@pxref{Commit Access}, for
5406 information on how to sign Git commits.)
5409 Advertise the channel introduction, for instance on your channel's web
5410 page. The channel introduction, as we saw above, is the commit/key
5411 pair---i.e., the commit that introduced @file{.guix-authorizations}, and
5412 the fingerprint of the OpenPGP used to sign it.
5415 Before pushing to your public Git repository, you can run @command{guix
5416 git-authenticate} to verify that you did sign all the commits you are
5417 about to push with an authorized key:
5420 guix git authenticate @var{commit} @var{signer}
5424 where @var{commit} and @var{signer} are your channel introduction.
5425 @xref{Invoking guix git authenticate}, for details.
5427 Publishing a signed channel requires discipline: any mistake, such as an
5428 unsigned commit or a commit signed by an unauthorized key, will prevent
5429 users from pulling from your channel---well, that's the whole point of
5430 authentication! Pay attention to merges in particular: merge commits
5431 are considered authentic if and only if they are signed by a key present
5432 in the @file{.guix-authorizations} file of @emph{both} branches.
5435 @section Primary URL
5437 @cindex primary URL, channels
5438 Channel authors can indicate the primary URL of their channel's Git
5439 repository in the @file{.guix-channel} file, like so:
5444 (url "https://example.org/guix.git"))
5447 This allows @command{guix pull} to determine whether it is pulling code
5448 from a mirror of the channel; when that is the case, it warns the user
5449 that the mirror might be stale and displays the primary URL@. That way,
5450 users cannot be tricked into fetching code from a stale mirror that does
5451 not receive security updates.
5453 This feature only makes sense for authenticated repositories, such as
5454 the official @code{guix} channel, for which @command{guix pull} ensures
5455 the code it fetches is authentic.
5457 @node Writing Channel News
5458 @section Writing Channel News
5460 @cindex news, for channels
5461 Channel authors may occasionally want to communicate to their users
5462 information about important changes in the channel. You'd send them all
5463 an email, but that's not convenient.
5465 Instead, channels can provide a @dfn{news file}; when the channel users
5466 run @command{guix pull}, that news file is automatically read and
5467 @command{guix pull --news} can display the announcements that correspond
5468 to the new commits that have been pulled, if any.
5470 To do that, channel authors must first declare the name of the news file
5471 in their @file{.guix-channel} file:
5476 (news-file "etc/news.txt"))
5479 The news file itself, @file{etc/news.txt} in this example, must look
5480 something like this:
5485 (entry (tag "the-bug-fix")
5486 (title (en "Fixed terrible bug")
5488 (body (en "@@emph@{Good news@}! It's fixed!")
5489 (eo "Certe ĝi pli bone funkcias nun!")))
5490 (entry (commit "bdcabe815cd28144a2d2b4bc3c5057b051fa9906")
5491 (title (en "Added a great package")
5492 (ca "Què vol dir guix?"))
5493 (body (en "Don't miss the @@code@{hello@} package!"))))
5496 While the news file is using the Scheme syntax, avoid naming it with a
5497 @file{.scm} extension or else it will get picked up when building the
5498 channel and yield an error since it is not a valid module.
5499 Alternatively, you can move the channel module to a subdirectory and
5500 store the news file in another directory.
5502 The file consists of a list of @dfn{news entries}. Each entry is
5503 associated with a commit or tag: it describes changes made in this
5504 commit, possibly in preceding commits as well. Users see entries only
5505 the first time they obtain the commit the entry refers to.
5507 The @code{title} field should be a one-line summary while @code{body}
5508 can be arbitrarily long, and both can contain Texinfo markup
5509 (@pxref{Overview,,, texinfo, GNU Texinfo}). Both the title and body are
5510 a list of language tag/message tuples, which allows @command{guix pull}
5511 to display news in the language that corresponds to the user's locale.
5513 If you want to translate news using a gettext-based workflow, you can
5514 extract translatable strings with @command{xgettext} (@pxref{xgettext
5515 Invocation,,, gettext, GNU Gettext Utilities}). For example, assuming
5516 you write news entries in English first, the command below creates a PO
5517 file containing the strings to translate:
5520 xgettext -o news.po -l scheme -ken etc/news.txt
5523 To sum up, yes, you could use your channel as a blog. But beware, this
5524 is @emph{not quite} what your users might expect.
5526 @c *********************************************************************
5528 @chapter Development
5530 @cindex software development
5531 If you are a software developer, Guix provides tools that you should find
5532 helpful---independently of the language you're developing in. This is what
5533 this chapter is about.
5535 The @command{guix environment} command provides a convenient way to set up
5536 @dfn{development environments} containing all the dependencies and tools
5537 necessary to work on the software package of your choice. The @command{guix
5538 pack} command allows you to create @dfn{application bundles} that can be
5539 easily distributed to users who do not run Guix.
5542 * Invoking guix environment:: Setting up development environments.
5543 * Invoking guix pack:: Creating software bundles.
5544 * The GCC toolchain:: Working with languages supported by GCC.
5545 * Invoking guix git authenticate:: Authenticating Git repositories.
5548 @node Invoking guix environment
5549 @section Invoking @command{guix environment}
5551 @cindex reproducible build environments
5552 @cindex development environments
5553 @cindex @command{guix environment}
5554 @cindex environment, package build environment
5555 The purpose of @command{guix environment} is to assist hackers in
5556 creating reproducible development environments without polluting their
5557 package profile. The @command{guix environment} tool takes one or more
5558 packages, builds all of their inputs, and creates a shell
5559 environment to use them.
5561 The general syntax is:
5564 guix environment @var{options} @var{package}@dots{}
5567 The following example spawns a new shell set up for the development of
5571 guix environment guile
5574 If the needed dependencies are not built yet, @command{guix environment}
5575 automatically builds them. The environment of the new shell is an
5576 augmented version of the environment that @command{guix environment} was
5577 run in. It contains the necessary search paths for building the given
5578 package added to the existing environment variables. To create
5579 a ``pure'' environment, in which the original environment variables have
5580 been unset, use the @option{--pure} option@footnote{Users sometimes
5581 wrongfully augment environment variables such as @env{PATH} in their
5582 @file{~/.bashrc} file. As a consequence, when @command{guix
5583 environment} launches it, Bash may read @file{~/.bashrc}, thereby
5584 introducing ``impurities'' in these environment variables. It is an
5585 error to define such environment variables in @file{.bashrc}; instead,
5586 they should be defined in @file{.bash_profile}, which is sourced only by
5587 log-in shells. @xref{Bash Startup Files,,, bash, The GNU Bash Reference
5588 Manual}, for details on Bash start-up files.}.
5590 Exiting from a Guix environment is the same as exiting from the shell,
5591 and will place the user back in the old environment before @command{guix
5592 environment} was invoked. The next garbage collection (@pxref{Invoking
5593 guix gc}) will clean up packages that were installed from within the
5594 environment and are no longer used outside of it.
5596 @vindex GUIX_ENVIRONMENT
5597 @command{guix environment} defines the @env{GUIX_ENVIRONMENT}
5598 variable in the shell it spawns; its value is the file name of the
5599 profile of this environment. This allows users to, say, define a
5600 specific prompt for development environments in their @file{.bashrc}
5601 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
5604 if [ -n "$GUIX_ENVIRONMENT" ]
5606 export PS1="\u@@\h \w [dev]\$ "
5611 ...@: or to browse the profile:
5614 $ ls "$GUIX_ENVIRONMENT/bin"
5617 Additionally, more than one package may be specified, in which case the
5618 union of the inputs for the given packages are used. For example, the
5619 command below spawns a shell where all of the dependencies of both Guile
5620 and Emacs are available:
5623 guix environment guile emacs
5626 Sometimes an interactive shell session is not desired. An arbitrary
5627 command may be invoked by placing the @code{--} token to separate the
5628 command from the rest of the arguments:
5631 guix environment guile -- make -j4
5634 In other situations, it is more convenient to specify the list of
5635 packages needed in the environment. For example, the following command
5636 runs @command{python} from an environment containing Python@tie{}2.7 and
5640 guix environment --ad-hoc python2-numpy python-2.7 -- python
5643 Furthermore, one might want the dependencies of a package and also some
5644 additional packages that are not build-time or runtime dependencies, but
5645 are useful when developing nonetheless. Because of this, the
5646 @option{--ad-hoc} flag is positional. Packages appearing before
5647 @option{--ad-hoc} are interpreted as packages whose dependencies will be
5648 added to the environment. Packages appearing after are interpreted as
5649 packages that will be added to the environment directly. For example,
5650 the following command creates a Guix development environment that
5651 additionally includes Git and strace:
5654 guix environment --pure guix --ad-hoc git strace
5658 Sometimes it is desirable to isolate the environment as much as
5659 possible, for maximal purity and reproducibility. In particular, when
5660 using Guix on a host distro that is not Guix System, it is desirable to
5661 prevent access to @file{/usr/bin} and other system-wide resources from
5662 the development environment. For example, the following command spawns
5663 a Guile REPL in a ``container'' where only the store and the current
5664 working directory are mounted:
5667 guix environment --ad-hoc --container guile -- guile
5671 The @option{--container} option requires Linux-libre 3.19 or newer.
5674 @cindex certificates
5675 Another typical use case for containers is to run security-sensitive
5676 applications such as a web browser. To run Eolie, we must expose and
5677 share some files and directories; we include @code{nss-certs} and expose
5678 @file{/etc/ssl/certs/} for HTTPS authentication; finally we preserve the
5679 @env{DISPLAY} environment variable since containerized graphical
5680 applications won't display without it.
5683 guix environment --preserve='^DISPLAY$' --container --network \
5684 --expose=/etc/machine-id \
5685 --expose=/etc/ssl/certs/ \
5686 --share=$HOME/.local/share/eolie/=$HOME/.local/share/eolie/ \
5687 --ad-hoc eolie nss-certs dbus -- eolie
5690 The available options are summarized below.
5693 @item --root=@var{file}
5694 @itemx -r @var{file}
5695 @cindex persistent environment
5696 @cindex garbage collector root, for environments
5697 Make @var{file} a symlink to the profile for this environment, and
5698 register it as a garbage collector root.
5700 This is useful if you want to protect your environment from garbage
5701 collection, to make it ``persistent''.
5703 When this option is omitted, the environment is protected from garbage
5704 collection only for the duration of the @command{guix environment}
5705 session. This means that next time you recreate the same environment,
5706 you could have to rebuild or re-download packages. @xref{Invoking guix
5707 gc}, for more on GC roots.
5709 @item --expression=@var{expr}
5710 @itemx -e @var{expr}
5711 Create an environment for the package or list of packages that
5712 @var{expr} evaluates to.
5714 For example, running:
5717 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
5720 starts a shell with the environment for this specific variant of the
5726 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
5729 starts a shell with all the base system packages available.
5731 The above commands only use the default output of the given packages.
5732 To select other outputs, two element tuples can be specified:
5735 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
5738 @item --load=@var{file}
5739 @itemx -l @var{file}
5740 Create an environment for the package or list of packages that the code
5741 within @var{file} evaluates to.
5743 As an example, @var{file} might contain a definition like this
5744 (@pxref{Defining Packages}):
5747 @verbatiminclude environment-gdb.scm
5750 @item --manifest=@var{file}
5751 @itemx -m @var{file}
5752 Create an environment for the packages contained in the manifest object
5753 returned by the Scheme code in @var{file}. This option can be repeated
5754 several times, in which case the manifests are concatenated.
5756 This is similar to the same-named option in @command{guix package}
5757 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
5761 Include all specified packages in the resulting environment, as if an
5762 @i{ad hoc} package were defined with them as inputs. This option is
5763 useful for quickly creating an environment without having to write a
5764 package expression to contain the desired inputs.
5766 For instance, the command:
5769 guix environment --ad-hoc guile guile-sdl -- guile
5772 runs @command{guile} in an environment where Guile and Guile-SDL are
5775 Note that this example implicitly asks for the default output of
5776 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
5777 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
5778 of @code{glib} (@pxref{Packages with Multiple Outputs}).
5780 This option may be composed with the default behavior of @command{guix
5781 environment}. Packages appearing before @option{--ad-hoc} are
5782 interpreted as packages whose dependencies will be added to the
5783 environment, the default behavior. Packages appearing after are
5784 interpreted as packages that will be added to the environment directly.
5787 Unset existing environment variables when building the new environment, except
5788 those specified with @option{--preserve} (see below). This has the effect of
5789 creating an environment in which search paths only contain package inputs.
5791 @item --preserve=@var{regexp}
5792 @itemx -E @var{regexp}
5793 When used alongside @option{--pure}, preserve the environment variables
5794 matching @var{regexp}---in other words, put them on a ``white list'' of
5795 environment variables that must be preserved. This option can be repeated
5799 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
5803 This example runs @command{mpirun} in a context where the only environment
5804 variables defined are @env{PATH}, environment variables whose name starts
5805 with @samp{SLURM}, as well as the usual ``precious'' variables (@env{HOME},
5808 @item --search-paths
5809 Display the environment variable definitions that make up the
5812 @item --system=@var{system}
5813 @itemx -s @var{system}
5814 Attempt to build for @var{system}---e.g., @code{i686-linux}.
5819 Run @var{command} within an isolated container. The current working
5820 directory outside the container is mapped inside the container.
5821 Additionally, unless overridden with @option{--user}, a dummy home
5822 directory is created that matches the current user's home directory, and
5823 @file{/etc/passwd} is configured accordingly.
5825 The spawned process runs as the current user outside the container. Inside
5826 the container, it has the same UID and GID as the current user, unless
5827 @option{--user} is passed (see below).
5831 For containers, share the network namespace with the host system.
5832 Containers created without this flag only have access to the loopback
5835 @item --link-profile
5837 For containers, link the environment profile to @file{~/.guix-profile}
5838 within the container and set @code{GUIX_ENVIRONMENT} to that.
5839 This is equivalent to making @file{~/.guix-profile} a symlink to the
5840 actual profile within the container.
5841 Linking will fail and abort the environment if the directory already
5842 exists, which will certainly be the case if @command{guix environment}
5843 was invoked in the user's home directory.
5845 Certain packages are configured to look in @file{~/.guix-profile} for
5846 configuration files and data;@footnote{For example, the
5847 @code{fontconfig} package inspects @file{~/.guix-profile/share/fonts}
5848 for additional fonts.} @option{--link-profile} allows these programs to
5849 behave as expected within the environment.
5851 @item --user=@var{user}
5852 @itemx -u @var{user}
5853 For containers, use the username @var{user} in place of the current
5854 user. The generated @file{/etc/passwd} entry within the container will
5855 contain the name @var{user}, the home directory will be
5856 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
5857 the UID and GID inside the container are 1000. @var{user}
5858 need not exist on the system.
5860 Additionally, any shared or exposed path (see @option{--share} and
5861 @option{--expose} respectively) whose target is within the current user's
5862 home directory will be remapped relative to @file{/home/USER}; this
5863 includes the automatic mapping of the current working directory.
5866 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
5868 guix environment --container --user=foo \
5869 --expose=$HOME/test \
5870 --expose=/tmp/target=$HOME/target
5873 While this will limit the leaking of user identity through home paths
5874 and each of the user fields, this is only one useful component of a
5875 broader privacy/anonymity solution---not one in and of itself.
5878 For containers, the default behavior is to share the current working
5879 directory with the isolated container and immediately change to that
5880 directory within the container. If this is undesirable,
5881 @option{--no-cwd} will cause the current working directory to @emph{not}
5882 be automatically shared and will change to the user's home directory
5883 within the container instead. See also @option{--user}.
5885 @item --expose=@var{source}[=@var{target}]
5886 @itemx --share=@var{source}[=@var{target}]
5887 For containers, @option{--expose} (resp. @option{--share}) exposes the
5888 file system @var{source} from the host system as the read-only
5889 (resp. writable) file system @var{target} within the container. If
5890 @var{target} is not specified, @var{source} is used as the target mount
5891 point in the container.
5893 The example below spawns a Guile REPL in a container in which the user's
5894 home directory is accessible read-only via the @file{/exchange}
5898 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
5903 @command{guix environment}
5904 also supports all of the common build options that @command{guix
5905 build} supports (@pxref{Common Build Options}) as well as package
5906 transformation options (@pxref{Package Transformation Options}).
5908 @node Invoking guix pack
5909 @section Invoking @command{guix pack}
5911 Occasionally you want to pass software to people who are not (yet!)
5912 lucky enough to be using Guix. You'd tell them to run @command{guix
5913 package -i @var{something}}, but that's not possible in this case. This
5914 is where @command{guix pack} comes in.
5917 If you are looking for ways to exchange binaries among machines that
5918 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
5919 publish}, and @ref{Invoking guix archive}.
5924 @cindex application bundle
5925 @cindex software bundle
5926 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
5927 @dfn{software bundle}: it creates a tarball or some other archive
5928 containing the binaries of the software you're interested in, and all
5929 its dependencies. The resulting archive can be used on any machine that
5930 does not have Guix, and people can run the exact same binaries as those
5931 you have with Guix. The pack itself is created in a bit-reproducible
5932 fashion, so anyone can verify that it really contains the build results
5933 that you pretend to be shipping.
5935 For example, to create a bundle containing Guile, Emacs, Geiser, and all
5936 their dependencies, you can run:
5939 $ guix pack guile emacs geiser
5941 /gnu/store/@dots{}-pack.tar.gz
5944 The result here is a tarball containing a @file{/gnu/store} directory
5945 with all the relevant packages. The resulting tarball contains a
5946 @dfn{profile} with the three packages of interest; the profile is the
5947 same as would be created by @command{guix package -i}. It is this
5948 mechanism that is used to create Guix's own standalone binary tarball
5949 (@pxref{Binary Installation}).
5951 Users of this pack would have to run
5952 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
5953 find inconvenient. To work around it, you can create, say, a
5954 @file{/opt/gnu/bin} symlink to the profile:
5957 guix pack -S /opt/gnu/bin=bin guile emacs geiser
5961 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
5963 @cindex relocatable binaries, with @command{guix pack}
5964 What if the recipient of your pack does not have root privileges on
5965 their machine, and thus cannot unpack it in the root file system? In
5966 that case, you will want to use the @option{--relocatable} option (see
5967 below). This option produces @dfn{relocatable binaries}, meaning they
5968 they can be placed anywhere in the file system hierarchy: in the example
5969 above, users can unpack your tarball in their home directory and
5970 directly run @file{./opt/gnu/bin/guile}.
5972 @cindex Docker, build an image with guix pack
5973 Alternatively, you can produce a pack in the Docker image format using
5974 the following command:
5977 guix pack -f docker -S /bin=bin guile guile-readline
5981 The result is a tarball that can be passed to the @command{docker load}
5982 command, followed by @code{docker run}:
5985 docker load < @var{file}
5986 docker run -ti guile-guile-readline /bin/guile
5990 where @var{file} is the image returned by @var{guix pack}, and
5991 @code{guile-guile-readline} is its ``image tag''. See the
5992 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
5993 documentation} for more information.
5995 @cindex Singularity, build an image with guix pack
5996 @cindex SquashFS, build an image with guix pack
5997 Yet another option is to produce a SquashFS image with the following
6001 guix pack -f squashfs bash guile emacs geiser
6005 The result is a SquashFS file system image that can either be mounted or
6006 directly be used as a file system container image with the
6007 @uref{https://www.sylabs.io/docs/, Singularity container execution
6008 environment}, using commands like @command{singularity shell} or
6009 @command{singularity exec}.
6011 Several command-line options allow you to customize your pack:
6014 @item --format=@var{format}
6015 @itemx -f @var{format}
6016 Produce a pack in the given @var{format}.
6018 The available formats are:
6022 This is the default format. It produces a tarball containing all the
6023 specified binaries and symlinks.
6026 This produces a tarball that follows the
6027 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
6028 Docker Image Specification}. The ``repository name'' as it appears in
6029 the output of the @command{docker images} command is computed from
6030 package names passed on the command line or in the manifest file.
6033 This produces a SquashFS image containing all the specified binaries and
6034 symlinks, as well as empty mount points for virtual file systems like
6038 Singularity @emph{requires} you to provide @file{/bin/sh} in the image.
6039 For that reason, @command{guix pack -f squashfs} always implies @code{-S
6040 /bin=bin}. Thus, your @command{guix pack} invocation must always start
6041 with something like:
6044 guix pack -f squashfs bash @dots{}
6047 If you forget the @code{bash} (or similar) package, @command{singularity
6048 run} and @command{singularity exec} will fail with an unhelpful ``no
6049 such file or directory'' message.
6053 @cindex relocatable binaries
6056 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
6057 anywhere in the file system hierarchy and run from there.
6059 When this option is passed once, the resulting binaries require support for
6060 @dfn{user namespaces} in the kernel Linux; when passed
6061 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
6062 PRoot support, can be thought of as the abbreviation of ``Really
6063 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to
6064 other techniques if user namespaces are unavailable, and essentially
6065 work anywhere---see below for the implications.
6067 For example, if you create a pack containing Bash with:
6070 guix pack -RR -S /mybin=bin bash
6074 ...@: you can copy that pack to a machine that lacks Guix, and from your
6075 home directory as a normal user, run:
6083 In that shell, if you type @code{ls /gnu/store}, you'll notice that
6084 @file{/gnu/store} shows up and contains all the dependencies of
6085 @code{bash}, even though the machine actually lacks @file{/gnu/store}
6086 altogether! That is probably the simplest way to deploy Guix-built
6087 software on a non-Guix machine.
6090 By default, relocatable binaries rely on the @dfn{user namespace} feature of
6091 the kernel Linux, which allows unprivileged users to mount or change root.
6092 Old versions of Linux did not support it, and some GNU/Linux distributions
6095 To produce relocatable binaries that work even in the absence of user
6096 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
6097 case, binaries will try user namespace support and fall back to another
6098 @dfn{execution engine} if user namespaces are not supported. The
6099 following execution engines are supported:
6103 Try user namespaces and fall back to PRoot if user namespaces are not
6104 supported (see below).
6107 Try user namespaces and fall back to Fakechroot if user namespaces are
6108 not supported (see below).
6111 Run the program through user namespaces and abort if they are not
6115 Run through PRoot. The @uref{https://proot-me.github.io/, PRoot} program
6116 provides the necessary
6117 support for file system virtualization. It achieves that by using the
6118 @code{ptrace} system call on the running program. This approach has the
6119 advantage to work without requiring special kernel support, but it incurs
6120 run-time overhead every time a system call is made.
6123 Run through Fakechroot. @uref{https://github.com/dex4er/fakechroot/,
6124 Fakechroot} virtualizes file system accesses by intercepting calls to C
6125 library functions such as @code{open}, @code{stat}, @code{exec}, and so
6126 on. Unlike PRoot, it incurs very little overhead. However, it does not
6127 always work: for example, some file system accesses made from within the
6128 C library are not intercepted, and file system accesses made @i{via}
6129 direct syscalls are not intercepted either, leading to erratic behavior.
6132 @vindex GUIX_EXECUTION_ENGINE
6133 When running a wrapped program, you can explicitly request one of the
6134 execution engines listed above by setting the
6135 @env{GUIX_EXECUTION_ENGINE} environment variable accordingly.
6138 @cindex entry point, for Docker images
6139 @item --entry-point=@var{command}
6140 Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
6141 format supports it---currently @code{docker} and @code{squashfs} (Singularity)
6142 support it. @var{command} must be relative to the profile contained in the
6145 The entry point specifies the command that tools like @code{docker run} or
6146 @code{singularity run} automatically start by default. For example, you can
6150 guix pack -f docker --entry-point=bin/guile guile
6153 The resulting pack can easily be loaded and @code{docker run} with no extra
6154 arguments will spawn @code{bin/guile}:
6157 docker load -i pack.tar.gz
6158 docker run @var{image-id}
6161 @item --expression=@var{expr}
6162 @itemx -e @var{expr}
6163 Consider the package @var{expr} evaluates to.
6165 This has the same purpose as the same-named option in @command{guix
6166 build} (@pxref{Additional Build Options, @option{--expression} in
6167 @command{guix build}}).
6169 @item --manifest=@var{file}
6170 @itemx -m @var{file}
6171 Use the packages contained in the manifest object returned by the Scheme
6172 code in @var{file}. This option can be repeated several times, in which
6173 case the manifests are concatenated.
6175 This has a similar purpose as the same-named option in @command{guix
6176 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
6177 same manifest files. It allows you to define a collection of packages
6178 once and use it both for creating profiles and for creating archives
6179 for use on machines that do not have Guix installed. Note that you can
6180 specify @emph{either} a manifest file @emph{or} a list of packages,
6183 @item --system=@var{system}
6184 @itemx -s @var{system}
6185 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
6186 the system type of the build host.
6188 @item --target=@var{triplet}
6189 @cindex cross-compilation
6190 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
6191 as @code{"aarch64-linux-gnu"} (@pxref{Specifying target triplets, GNU
6192 configuration triplets,, autoconf, Autoconf}).
6194 @item --compression=@var{tool}
6195 @itemx -C @var{tool}
6196 Compress the resulting tarball using @var{tool}---one of @code{gzip},
6197 @code{zstd}, @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no
6200 @item --symlink=@var{spec}
6201 @itemx -S @var{spec}
6202 Add the symlinks specified by @var{spec} to the pack. This option can
6203 appear several times.
6205 @var{spec} has the form @code{@var{source}=@var{target}}, where
6206 @var{source} is the symlink that will be created and @var{target} is the
6209 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
6210 symlink pointing to the @file{bin} sub-directory of the profile.
6212 @item --save-provenance
6213 Save provenance information for the packages passed on the command line.
6214 Provenance information includes the URL and commit of the channels in use
6217 Provenance information is saved in the
6218 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
6219 usual package metadata---the name and version of each package, their
6220 propagated inputs, and so on. It is useful information to the recipient of
6221 the pack, who then knows how the pack was (supposedly) obtained.
6223 This option is not enabled by default because, like timestamps, provenance
6224 information contributes nothing to the build process. In other words, there
6225 is an infinity of channel URLs and commit IDs that can lead to the same pack.
6226 Recording such ``silent'' metadata in the output thus potentially breaks the
6227 source-to-binary bitwise reproducibility property.
6229 @item --root=@var{file}
6230 @itemx -r @var{file}
6231 @cindex garbage collector root, for packs
6232 Make @var{file} a symlink to the resulting pack, and register it as a garbage
6235 @item --localstatedir
6236 @itemx --profile-name=@var{name}
6237 Include the ``local state directory'', @file{/var/guix}, in the resulting
6238 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
6239 profile---by default @var{name} is @code{guix-profile}, which corresponds to
6240 @file{~root/.guix-profile}.
6242 @file{/var/guix} contains the store database (@pxref{The Store}) as well
6243 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
6244 the pack means that the store is ``complete'' and manageable by Guix;
6245 not providing it pack means that the store is ``dead'': items cannot be
6246 added to it or removed from it after extraction of the pack.
6248 One use case for this is the Guix self-contained binary tarball
6249 (@pxref{Binary Installation}).
6253 Print the name of the derivation that builds the pack.
6256 Use the bootstrap binaries to build the pack. This option is only
6257 useful to Guix developers.
6260 In addition, @command{guix pack} supports all the common build options
6261 (@pxref{Common Build Options}) and all the package transformation
6262 options (@pxref{Package Transformation Options}).
6265 @node The GCC toolchain
6266 @section The GCC toolchain
6270 @cindex linker wrapper
6271 @cindex toolchain, for C development
6272 @cindex toolchain, for Fortran development
6274 If you need a complete toolchain for compiling and linking C or C++
6275 source code, use the @code{gcc-toolchain} package. This package
6276 provides a complete GCC toolchain for C/C++ development, including GCC
6277 itself, the GNU C Library (headers and binaries, plus debugging symbols
6278 in the @code{debug} output), Binutils, and a linker wrapper.
6280 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
6281 passed to the linker, add corresponding @code{-rpath} arguments, and
6282 invoke the actual linker with this new set of arguments. You can instruct the
6283 wrapper to refuse to link against libraries not in the store by setting the
6284 @env{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
6286 The package @code{gfortran-toolchain} provides a complete GCC toolchain
6287 for Fortran development. For other languages, please use
6288 @samp{guix search gcc toolchain} (@pxref{guix-search,, Invoking guix package}).
6291 @node Invoking guix git authenticate
6292 @section Invoking @command{guix git authenticate}
6294 The @command{guix git authenticate} command authenticates a Git checkout
6295 following the same rule as for channels (@pxref{channel-authentication,
6296 channel authentication}). That is, starting from a given commit, it
6297 ensures that all subsequent commits are signed by an OpenPGP key whose
6298 fingerprint appears in the @file{.guix-authorizations} file of its
6301 You will find this command useful if you maintain a channel. But in
6302 fact, this authentication mechanism is useful in a broader context, so
6303 you might want to use it for Git repositories that have nothing to do
6306 The general syntax is:
6309 guix git authenticate @var{commit} @var{signer} [@var{options}@dots{}]
6312 By default, this command authenticates the Git checkout in the current
6313 directory; it outputs nothing and exits with exit code zero on success
6314 and non-zero on failure. @var{commit} above denotes the first commit
6315 where authentication takes place, and @var{signer} is the OpenPGP
6316 fingerprint of public key used to sign @var{commit}. Together, they
6317 form a ``channel introduction'' (@pxref{channel-authentication, channel
6318 introduction}). The options below allow you to fine-tune the process.
6321 @item --repository=@var{directory}
6322 @itemx -r @var{directory}
6323 Open the Git repository in @var{directory} instead of the current
6326 @item --keyring=@var{reference}
6327 @itemx -k @var{reference}
6328 Load OpenPGP keyring from @var{reference}, the reference of a branch
6329 such as @code{origin/keyring} or @code{my-keyring}. The branch must
6330 contain OpenPGP public keys in @file{.key} files, either in binary form
6331 or ``ASCII-armored''. By default the keyring is loaded from the branch
6332 named @code{keyring}.
6335 Display commit signing statistics upon completion.
6337 @item --cache-key=@var{key}
6338 Previously-authenticated commits are cached in a file under
6339 @file{~/.cache/guix/authentication}. This option forces the cache to be
6340 stored in file @var{key} in that directory.
6342 @item --historical-authorizations=@var{file}
6343 By default, any commit whose parent commit(s) lack the
6344 @file{.guix-authorizations} file is considered inauthentic. In
6345 contrast, this option considers the authorizations in @var{file} for any
6346 commit that lacks @file{.guix-authorizations}. The format of @var{file}
6347 is the same as that of @file{.guix-authorizations}
6348 (@pxref{channel-authorizations, @file{.guix-authorizations} format}).
6352 @c *********************************************************************
6353 @node Programming Interface
6354 @chapter Programming Interface
6356 GNU Guix provides several Scheme programming interfaces (APIs) to
6357 define, build, and query packages. The first interface allows users to
6358 write high-level package definitions. These definitions refer to
6359 familiar packaging concepts, such as the name and version of a package,
6360 its build system, and its dependencies. These definitions can then be
6361 turned into concrete build actions.
6363 Build actions are performed by the Guix daemon, on behalf of users. In a
6364 standard setup, the daemon has write access to the store---the
6365 @file{/gnu/store} directory---whereas users do not. The recommended
6366 setup also has the daemon perform builds in chroots, under specific
6367 build users, to minimize interference with the rest of the system.
6370 Lower-level APIs are available to interact with the daemon and the
6371 store. To instruct the daemon to perform a build action, users actually
6372 provide it with a @dfn{derivation}. A derivation is a low-level
6373 representation of the build actions to be taken, and the environment in
6374 which they should occur---derivations are to package definitions what
6375 assembly is to C programs. The term ``derivation'' comes from the fact
6376 that build results @emph{derive} from them.
6378 This chapter describes all these APIs in turn, starting from high-level
6379 package definitions.
6382 * Package Modules:: Packages from the programmer's viewpoint.
6383 * Defining Packages:: Defining new packages.
6384 * Defining Package Variants:: Customizing packages.
6385 * Build Systems:: Specifying how packages are built.
6386 * Build Phases:: Phases of the build process of a package.
6387 * Build Utilities:: Helpers for your package definitions and more.
6388 * The Store:: Manipulating the package store.
6389 * Derivations:: Low-level interface to package derivations.
6390 * The Store Monad:: Purely functional interface to the store.
6391 * G-Expressions:: Manipulating build expressions.
6392 * Invoking guix repl:: Programming Guix in Guile
6395 @node Package Modules
6396 @section Package Modules
6398 From a programming viewpoint, the package definitions of the
6399 GNU distribution are provided by Guile modules in the @code{(gnu packages
6400 @dots{})} name space@footnote{Note that packages under the @code{(gnu
6401 packages @dots{})} module name space are not necessarily ``GNU
6402 packages''. This module naming scheme follows the usual Guile module
6403 naming convention: @code{gnu} means that these modules are distributed
6404 as part of the GNU system, and @code{packages} identifies modules that
6405 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
6406 Reference Manual}). For instance, the @code{(gnu packages emacs)}
6407 module exports a variable named @code{emacs}, which is bound to a
6408 @code{<package>} object (@pxref{Defining Packages}).
6410 The @code{(gnu packages @dots{})} module name space is
6411 automatically scanned for packages by the command-line tools. For
6412 instance, when running @code{guix install emacs}, all the @code{(gnu
6413 packages @dots{})} modules are scanned until one that exports a package
6414 object whose name is @code{emacs} is found. This package search
6415 facility is implemented in the @code{(gnu packages)} module.
6417 @cindex customization, of packages
6418 @cindex package module search path
6419 Users can store package definitions in modules with different
6420 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
6421 name and module name must match. For instance, the @code{(my-packages
6422 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
6423 relative to the load path specified with @option{--load-path} or
6424 @env{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
6425 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
6426 these package definitions visible to the user interfaces:
6430 By adding the directory containing your package modules to the search path
6431 with the @code{-L} flag of @command{guix package} and other commands
6432 (@pxref{Common Build Options}), or by setting the @env{GUIX_PACKAGE_PATH}
6433 environment variable described below.
6436 By defining a @dfn{channel} and configuring @command{guix pull} so that it
6437 pulls from it. A channel is essentially a Git repository containing package
6438 modules. @xref{Channels}, for more information on how to define and use
6442 @env{GUIX_PACKAGE_PATH} works similarly to other search path variables:
6444 @defvr {Environment Variable} GUIX_PACKAGE_PATH
6445 This is a colon-separated list of directories to search for additional
6446 package modules. Directories listed in this variable take precedence
6447 over the own modules of the distribution.
6450 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
6451 each package is built based solely on other packages in the
6452 distribution. The root of this dependency graph is a small set of
6453 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
6454 bootstrap)} module. For more information on bootstrapping,
6455 @pxref{Bootstrapping}.
6457 @node Defining Packages
6458 @section Defining Packages
6460 The high-level interface to package definitions is implemented in the
6461 @code{(guix packages)} and @code{(guix build-system)} modules. As an
6462 example, the package definition, or @dfn{recipe}, for the GNU Hello
6463 package looks like this:
6466 (define-module (gnu packages hello)
6467 #:use-module (guix packages)
6468 #:use-module (guix download)
6469 #:use-module (guix build-system gnu)
6470 #:use-module (guix licenses)
6471 #:use-module (gnu packages gawk))
6473 (define-public hello
6479 (uri (string-append "mirror://gnu/hello/hello-" version
6483 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
6484 (build-system gnu-build-system)
6485 (arguments '(#:configure-flags '("--enable-silent-rules")))
6486 (inputs `(("gawk" ,gawk)))
6487 (synopsis "Hello, GNU world: An example GNU package")
6488 (description "Guess what GNU Hello prints!")
6489 (home-page "https://www.gnu.org/software/hello/")
6494 Without being a Scheme expert, the reader may have guessed the meaning
6495 of the various fields here. This expression binds the variable
6496 @code{hello} to a @code{<package>} object, which is essentially a record
6497 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
6498 This package object can be inspected using procedures found in the
6499 @code{(guix packages)} module; for instance, @code{(package-name hello)}
6500 returns---surprise!---@code{"hello"}.
6502 With luck, you may be able to import part or all of the definition of
6503 the package you are interested in from another repository, using the
6504 @code{guix import} command (@pxref{Invoking guix import}).
6506 In the example above, @code{hello} is defined in a module of its own,
6507 @code{(gnu packages hello)}. Technically, this is not strictly
6508 necessary, but it is convenient to do so: all the packages defined in
6509 modules under @code{(gnu packages @dots{})} are automatically known to
6510 the command-line tools (@pxref{Package Modules}).
6512 There are a few points worth noting in the above package definition:
6516 The @code{source} field of the package is an @code{<origin>} object
6517 (@pxref{origin Reference}, for the complete reference).
6518 Here, the @code{url-fetch} method from @code{(guix download)} is used,
6519 meaning that the source is a file to be downloaded over FTP or HTTP.
6521 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
6522 the GNU mirrors defined in @code{(guix download)}.
6524 The @code{sha256} field specifies the expected SHA256 hash of the file
6525 being downloaded. It is mandatory, and allows Guix to check the
6526 integrity of the file. The @code{(base32 @dots{})} form introduces the
6527 base32 representation of the hash. You can obtain this information with
6528 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
6529 hash} (@pxref{Invoking guix hash}).
6532 When needed, the @code{origin} form can also have a @code{patches} field
6533 listing patches to be applied, and a @code{snippet} field giving a
6534 Scheme expression to modify the source code.
6537 @cindex GNU Build System
6538 The @code{build-system} field specifies the procedure to build the
6539 package (@pxref{Build Systems}). Here, @code{gnu-build-system}
6540 represents the familiar GNU Build System, where packages may be
6541 configured, built, and installed with the usual @code{./configure &&
6542 make && make check && make install} command sequence.
6544 When you start packaging non-trivial software, you may need tools to
6545 manipulate those build phases, manipulate files, and so on. @xref{Build
6546 Utilities}, for more on this.
6549 The @code{arguments} field specifies options for the build system
6550 (@pxref{Build Systems}). Here it is interpreted by
6551 @code{gnu-build-system} as a request run @file{configure} with the
6552 @option{--enable-silent-rules} flag.
6558 What about these quote (@code{'}) characters? They are Scheme syntax to
6559 introduce a literal list; @code{'} is synonymous with @code{quote}.
6560 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
6561 for details. Here the value of the @code{arguments} field is a list of
6562 arguments passed to the build system down the road, as with @code{apply}
6563 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
6566 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
6567 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
6568 @code{#:configure-flags} is a keyword used to pass a keyword argument
6569 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
6573 The @code{inputs} field specifies inputs to the build process---i.e.,
6574 build-time or run-time dependencies of the package. Here, we define an
6575 input called @code{"gawk"} whose value is that of the @code{gawk}
6576 variable; @code{gawk} is itself bound to a @code{<package>} object.
6578 @cindex backquote (quasiquote)
6581 @cindex comma (unquote)
6585 @findex unquote-splicing
6586 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
6587 us to introduce a literal list in the @code{inputs} field, while
6588 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
6589 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
6592 Note that GCC, Coreutils, Bash, and other essential tools do not need to
6593 be specified as inputs here. Instead, @code{gnu-build-system} takes care
6594 of ensuring that they are present (@pxref{Build Systems}).
6596 However, any other dependencies need to be specified in the
6597 @code{inputs} field. Any dependency not specified here will simply be
6598 unavailable to the build process, possibly leading to a build failure.
6601 @xref{package Reference}, for a full description of possible fields.
6603 Once a package definition is in place, the
6604 package may actually be built using the @code{guix build} command-line
6605 tool (@pxref{Invoking guix build}), troubleshooting any build failures
6606 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
6607 package definition using the @command{guix edit} command
6608 (@pxref{Invoking guix edit}).
6609 @xref{Packaging Guidelines}, for
6610 more information on how to test package definitions, and
6611 @ref{Invoking guix lint}, for information on how to check a definition
6612 for style conformance.
6613 @vindex GUIX_PACKAGE_PATH
6614 Lastly, @pxref{Channels}, for information
6615 on how to extend the distribution by adding your own package definitions
6618 Finally, updating the package definition to a new upstream version
6619 can be partly automated by the @command{guix refresh} command
6620 (@pxref{Invoking guix refresh}).
6622 Behind the scenes, a derivation corresponding to the @code{<package>}
6623 object is first computed by the @code{package-derivation} procedure.
6624 That derivation is stored in a @file{.drv} file under @file{/gnu/store}.
6625 The build actions it prescribes may then be realized by using the
6626 @code{build-derivations} procedure (@pxref{The Store}).
6628 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
6629 Return the @code{<derivation>} object of @var{package} for @var{system}
6630 (@pxref{Derivations}).
6632 @var{package} must be a valid @code{<package>} object, and @var{system}
6633 must be a string denoting the target system type---e.g.,
6634 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
6635 must be a connection to the daemon, which operates on the store
6636 (@pxref{The Store}).
6640 @cindex cross-compilation
6641 Similarly, it is possible to compute a derivation that cross-builds a
6642 package for some other system:
6644 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
6645 @var{package} @var{target} [@var{system}]
6646 Return the @code{<derivation>} object of @var{package} cross-built from
6647 @var{system} to @var{target}.
6649 @var{target} must be a valid GNU triplet denoting the target hardware
6650 and operating system, such as @code{"aarch64-linux-gnu"}
6651 (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
6654 Once you have package definitions, you can easily define @emph{variants}
6655 of those packages. @xref{Defining Package Variants}, for more on that.
6658 * package Reference:: The package data type.
6659 * origin Reference:: The origin data type.
6663 @node package Reference
6664 @subsection @code{package} Reference
6666 This section summarizes all the options available in @code{package}
6667 declarations (@pxref{Defining Packages}).
6669 @deftp {Data Type} package
6670 This is the data type representing a package recipe.
6674 The name of the package, as a string.
6676 @item @code{version}
6677 The version of the package, as a string.
6680 An object telling how the source code for the package should be
6681 acquired. Most of the time, this is an @code{origin} object, which
6682 denotes a file fetched from the Internet (@pxref{origin Reference}). It
6683 can also be any other ``file-like'' object such as a @code{local-file},
6684 which denotes a file from the local file system (@pxref{G-Expressions,
6685 @code{local-file}}).
6687 @item @code{build-system}
6688 The build system that should be used to build the package (@pxref{Build
6691 @item @code{arguments} (default: @code{'()})
6692 The arguments that should be passed to the build system. This is a
6693 list, typically containing sequential keyword-value pairs.
6695 @item @code{inputs} (default: @code{'()})
6696 @itemx @code{native-inputs} (default: @code{'()})
6697 @itemx @code{propagated-inputs} (default: @code{'()})
6698 @cindex inputs, of packages
6699 These fields list dependencies of the package. Each one is a list of
6700 tuples, where each tuple has a label for the input (a string) as its
6701 first element, a package, origin, or derivation as its second element,
6702 and optionally the name of the output thereof that should be used, which
6703 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
6704 more on package outputs). For example, the list below specifies three
6708 `(("libffi" ,libffi)
6709 ("libunistring" ,libunistring)
6710 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
6713 @cindex cross compilation, package dependencies
6714 The distinction between @code{native-inputs} and @code{inputs} is
6715 necessary when considering cross-compilation. When cross-compiling,
6716 dependencies listed in @code{inputs} are built for the @emph{target}
6717 architecture; conversely, dependencies listed in @code{native-inputs}
6718 are built for the architecture of the @emph{build} machine.
6720 @code{native-inputs} is typically used to list tools needed at
6721 build time, but not at run time, such as Autoconf, Automake, pkg-config,
6722 Gettext, or Bison. @command{guix lint} can report likely mistakes in
6723 this area (@pxref{Invoking guix lint}).
6725 @anchor{package-propagated-inputs}
6726 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
6727 specified packages will be automatically installed to profiles
6728 (@pxref{Features, the role of profiles in Guix}) alongside the package
6729 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
6730 package}}, for information on how @command{guix package} deals with
6733 For example this is necessary when packaging a C/C++ library that needs
6734 headers of another library to compile, or when a pkg-config file refers
6735 to another one @i{via} its @code{Requires} field.
6737 Another example where @code{propagated-inputs} is useful is for languages
6738 that lack a facility to record the run-time search path akin to the
6739 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
6740 more. When packaging libraries written in those languages, ensure they
6741 can find library code they depend on at run time by listing run-time
6742 dependencies in @code{propagated-inputs} rather than @code{inputs}.
6744 @item @code{outputs} (default: @code{'("out")})
6745 The list of output names of the package. @xref{Packages with Multiple
6746 Outputs}, for typical uses of additional outputs.
6748 @item @code{native-search-paths} (default: @code{'()})
6749 @itemx @code{search-paths} (default: @code{'()})
6750 A list of @code{search-path-specification} objects describing
6751 search-path environment variables honored by the package.
6753 @item @code{replacement} (default: @code{#f})
6754 This must be either @code{#f} or a package object that will be used as a
6755 @dfn{replacement} for this package. @xref{Security Updates, grafts},
6758 @item @code{synopsis}
6759 A one-line description of the package.
6761 @item @code{description}
6762 A more elaborate description of the package.
6764 @item @code{license}
6765 @cindex license, of packages
6766 The license of the package; a value from @code{(guix licenses)},
6767 or a list of such values.
6769 @item @code{home-page}
6770 The URL to the home-page of the package, as a string.
6772 @item @code{supported-systems} (default: @code{%supported-systems})
6773 The list of systems supported by the package, as strings of the form
6774 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
6776 @item @code{location} (default: source location of the @code{package} form)
6777 The source location of the package. It is useful to override this when
6778 inheriting from another package, in which case this field is not
6779 automatically corrected.
6783 @deffn {Scheme Syntax} this-package
6784 When used in the @emph{lexical scope} of a package field definition, this
6785 identifier resolves to the package being defined.
6787 The example below shows how to add a package as a native input of itself when
6795 ;; When cross-compiled, Guile, for example, depends on
6796 ;; a native version of itself. Add it here.
6797 (native-inputs (if (%current-target-system)
6798 `(("self" ,this-package))
6802 It is an error to refer to @code{this-package} outside a package definition.
6805 Because packages are regular Scheme objects that capture a complete
6806 dependency graph and associated build procedures, it is often useful to
6807 write procedures that take a package and return a modified version
6808 thereof according to some parameters. Below are a few examples.
6810 @cindex tool chain, choosing a package's tool chain
6811 @deffn {Scheme Procedure} package-with-c-toolchain @var{package} @var{toolchain}
6812 Return a variant of @var{package} that uses @var{toolchain} instead of
6813 the default GNU C/C++ toolchain. @var{toolchain} must be a list of
6814 inputs (label/package tuples) providing equivalent functionality, such
6815 as the @code{gcc-toolchain} package.
6817 The example below returns a variant of the @code{hello} package built
6818 with GCC@tie{}10.x and the rest of the GNU tool chain (Binutils and the
6819 GNU C Library) instead of the default tool chain:
6822 (let ((toolchain (specification->package "gcc-toolchain@@10")))
6823 (package-with-c-toolchain hello `(("toolchain" ,toolchain))))
6826 The build tool chain is part of the @dfn{implicit inputs} of
6827 packages---it's usually not listed as part of the various ``inputs''
6828 fields and is instead pulled in by the build system. Consequently, this
6829 procedure works by changing the build system of @var{package} so that it
6830 pulls in @var{toolchain} instead of the defaults. @ref{Build Systems},
6831 for more on build systems.
6834 @node origin Reference
6835 @subsection @code{origin} Reference
6837 This section documents @dfn{origins}. An @code{origin} declaration
6838 specifies data that must be ``produced''---downloaded, usually---and
6839 whose content hash is known in advance. Origins are primarily used to
6840 represent the source code of packages (@pxref{Defining Packages}). For
6841 that reason, the @code{origin} form allows you to declare patches to
6842 apply to the original source code as well as code snippets to modify it.
6844 @deftp {Data Type} origin
6845 This is the data type representing a source code origin.
6849 An object containing the URI of the source. The object type depends on
6850 the @code{method} (see below). For example, when using the
6851 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
6852 values are: a URL represented as a string, or a list thereof.
6854 @cindex fixed-output derivations, for download
6856 A monadic procedure that handles the given URI@. The procedure must
6857 accept at least three arguments: the value of the @code{uri} field and
6858 the hash algorithm and hash value specified by the @code{hash} field.
6859 It must return a store item or a derivation in the store monad
6860 (@pxref{The Store Monad}); most methods return a fixed-output derivation
6861 (@pxref{Derivations}).
6863 Commonly used methods include @code{url-fetch}, which fetches data from
6864 a URL, and @code{git-fetch}, which fetches data from a Git repository
6868 A bytevector containing the SHA-256 hash of the source. This is
6869 equivalent to providing a @code{content-hash} SHA256 object in the
6870 @code{hash} field described below.
6873 The @code{content-hash} object of the source---see below for how to use
6874 @code{content-hash}.
6876 You can obtain this information using @code{guix download}
6877 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
6880 @item @code{file-name} (default: @code{#f})
6881 The file name under which the source code should be saved. When this is
6882 @code{#f}, a sensible default value will be used in most cases. In case
6883 the source is fetched from a URL, the file name from the URL will be
6884 used. For version control checkouts, it is recommended to provide the
6885 file name explicitly because the default is not very descriptive.
6887 @item @code{patches} (default: @code{'()})
6888 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
6889 file-like objects}) pointing to patches to be applied to the source.
6891 This list of patches must be unconditional. In particular, it cannot
6892 depend on the value of @code{%current-system} or
6893 @code{%current-target-system}.
6895 @item @code{snippet} (default: @code{#f})
6896 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
6897 in the source directory. This is a convenient way to modify the source,
6898 sometimes more convenient than a patch.
6900 @item @code{patch-flags} (default: @code{'("-p1")})
6901 A list of command-line flags that should be passed to the @code{patch}
6904 @item @code{patch-inputs} (default: @code{#f})
6905 Input packages or derivations to the patching process. When this is
6906 @code{#f}, the usual set of inputs necessary for patching are provided,
6907 such as GNU@tie{}Patch.
6909 @item @code{modules} (default: @code{'()})
6910 A list of Guile modules that should be loaded during the patching
6911 process and while running the code in the @code{snippet} field.
6913 @item @code{patch-guile} (default: @code{#f})
6914 The Guile package that should be used in the patching process. When
6915 this is @code{#f}, a sensible default is used.
6919 @deftp {Data Type} content-hash @var{value} [@var{algorithm}]
6920 Construct a content hash object for the given @var{algorithm}, and with
6921 @var{value} as its hash value. When @var{algorithm} is omitted, assume
6922 it is @code{sha256}.
6924 @var{value} can be a literal string, in which case it is base32-decoded,
6925 or it can be a bytevector.
6927 The following forms are all equivalent:
6930 (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj")
6931 (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"
6933 (content-hash (base32
6934 "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"))
6935 (content-hash (base64 "kkb+RPaP7uyMZmu4eXPVkM4BN8yhRd8BTHLslb6f/Rc=")
6939 Technically, @code{content-hash} is currently implemented as a macro.
6940 It performs sanity checks at macro-expansion time, when possible, such
6941 as ensuring that @var{value} has the right size for @var{algorithm}.
6944 As we have seen above, how exactly the data an origin refers to is
6945 retrieved is determined by its @code{method} field. The @code{(guix
6946 download)} module provides the most common method, @code{url-fetch},
6949 @deffn {Scheme Procedure} url-fetch @var{url} @var{hash-algo} @var{hash} @
6950 [name] [#:executable? #f]
6951 Return a fixed-output derivation that fetches data from @var{url} (a
6952 string, or a list of strings denoting alternate URLs), which is expected
6953 to have hash @var{hash} of type @var{hash-algo} (a symbol). By default,
6954 the file name is the base name of URL; optionally, @var{name} can
6955 specify a different file name. When @var{executable?} is true, make the
6956 downloaded file executable.
6958 When one of the URL starts with @code{mirror://}, then its host part is
6959 interpreted as the name of a mirror scheme, taken from @file{%mirror-file}.
6961 Alternatively, when URL starts with @code{file://}, return the
6962 corresponding file name in the store.
6965 Likewise, the @code{(guix git-download)} module defines the
6966 @code{git-fetch} origin method, which fetches data from a Git version
6967 control repository, and the @code{git-reference} data type to describe
6968 the repository and revision to fetch.
6970 @deffn {Scheme Procedure} git-fetch @var{ref} @var{hash-algo} @var{hash}
6971 Return a fixed-output derivation that fetches @var{ref}, a
6972 @code{<git-reference>} object. The output is expected to have recursive
6973 hash @var{hash} of type @var{hash-algo} (a symbol). Use @var{name} as
6974 the file name, or a generic name if @code{#f}.
6977 @deftp {Data Type} git-reference
6978 This data type represents a Git reference for @code{git-fetch} to
6983 The URL of the Git repository to clone.
6986 This string denotes either the commit to fetch (a hexadecimal string,
6987 either the full SHA1 commit or a ``short'' commit string; the latter is
6988 not recommended) or the tag to fetch.
6990 @item @code{recursive?} (default: @code{#f})
6991 This Boolean indicates whether to recursively fetch Git sub-modules.
6994 The example below denotes the @code{v2.10} tag of the GNU@tie{}Hello
6999 (url "https://git.savannah.gnu.org/git/hello.git")
7003 This is equivalent to the reference below, which explicitly names the
7008 (url "https://git.savannah.gnu.org/git/hello.git")
7009 (commit "dc7dc56a00e48fe6f231a58f6537139fe2908fb9"))
7013 For Mercurial repositories, the module @code{(guix hg-download)} defines
7014 the @code{hg-fetch} origin method and @code{hg-reference} data type for
7015 support of the Mercurial version control system.
7017 @deffn {Scheme Procedure} hg-fetch @var{ref} @var{hash-algo} @var{hash} @
7019 Return a fixed-output derivation that fetches @var{ref}, a
7020 @code{<hg-reference>} object. The output is expected to have recursive
7021 hash @var{hash} of type @var{hash-algo} (a symbol). Use @var{name} as
7022 the file name, or a generic name if @code{#false}.
7025 @node Defining Package Variants
7026 @section Defining Package Variants
7028 @cindex customizing packages
7029 @cindex variants, of packages
7030 One of the nice things with Guix is that, given a package definition,
7031 you can easily @emph{derive} variants of that package---for a different
7032 upstream version, with different dependencies, different compilation
7033 options, and so on. Some of these custom packages can be defined
7034 straight from the command line (@pxref{Package Transformation Options}).
7035 This section describes how to define package variants in code. This can
7036 be useful in ``manifests'' (@pxref{profile-manifest,
7037 @option{--manifest}}) and in your own package collection
7038 (@pxref{Creating a Channel}), among others!
7040 @cindex inherit, for package definitions
7041 As discussed earlier, packages are first-class objects in the Scheme
7042 language. The @code{(guix packages)} module provides the @code{package}
7043 construct to define new package objects (@pxref{package Reference}).
7044 The easiest way to define a package variant is using the @code{inherit}
7045 keyword together with @code{package}. This allows you to inherit from a
7046 package definition while overriding the fields you want.
7048 For example, given the @code{hello} variable, which contains a
7049 definition for the current version of GNU@tie{}Hello, here's how you
7050 would define a variant for version 2.2 (released in 2006, it's
7054 (use-modules (gnu packages base)) ;for 'hello'
7062 (uri (string-append "mirror://gnu/hello/hello-" version
7066 "0lappv4slgb5spyqbh6yl5r013zv72yqg2pcl30mginf3wdqd8k9"))))))
7069 The example above corresponds to what the @option{--with-source} package
7070 transformation option does. Essentially @code{hello-2.2} preserves all
7071 the fields of @code{hello}, except @code{version} and @code{source},
7072 which it overrides. Note that the original @code{hello} variable is
7073 still there, in the @code{(gnu packages base)} module, unchanged. When
7074 you define a custom package like this, you are really @emph{adding} a
7075 new package definition; the original one remains available.
7077 You can just as well define variants with a different set of
7078 dependencies than the original package. For example, the default
7079 @code{gdb} package depends on @code{guile}, but since that is an
7080 optional dependency, you can define a variant that removes that
7084 (use-modules (gnu packages gdb) ;for 'gdb'
7085 (srfi srfi-1)) ;for 'alist-delete'
7087 (define gdb-sans-guile
7090 (inputs (alist-delete "guile"
7091 (package-inputs gdb)))))
7094 The @code{alist-delete} call above removes the tuple from the
7095 @code{inputs} field that has @code{"guile"} as its first element
7096 (@pxref{SRFI-1 Association Lists,,, guile, GNU Guile Reference
7099 In some cases, you may find it useful to write functions
7100 (``procedures'', in Scheme parlance) that return a package based on some
7101 parameters. For example, consider the @code{luasocket} library for the
7102 Lua programming language. We want to create @code{luasocket} packages
7103 for major versions of Lua. One way to do that is to define a procedure
7104 that takes a Lua package and returns a @code{luasocket} package that
7108 (define (make-lua-socket name lua)
7109 ;; Return a luasocket package built with LUA.
7113 ;; several fields omitted
7116 (synopsis "Socket library for Lua")))
7118 (define-public lua5.1-socket
7119 (make-lua-socket "lua5.1-socket" lua-5.1))
7121 (define-public lua5.2-socket
7122 (make-lua-socket "lua5.2-socket" lua-5.2))
7125 Here we have defined packages @code{lua5.1-socket} and
7126 @code{lua5.2-socket} by calling @code{make-lua-socket} with different
7127 arguments. @xref{Procedures,,, guile, GNU Guile Reference Manual}, for
7128 more info on procedures. Having top-level public definitions for these
7129 two packages means that they can be referred to from the command line
7130 (@pxref{Package Modules}).
7132 @cindex package transformations
7133 These are pretty simple package variants. As a convenience, the
7134 @code{(guix transformations)} module provides a high-level interface
7135 that directly maps to the more sophisticated package transformation
7136 options (@pxref{Package Transformation Options}):
7138 @deffn {Scheme Procedure} options->transformation @var{opts}
7139 Return a procedure that, when passed an object to build (package,
7140 derivation, etc.), applies the transformations specified by @var{opts} and returns
7141 the resulting objects. @var{opts} must be a list of symbol/string pairs such as:
7144 ((with-branch . "guile-gcrypt=master")
7145 (without-tests . "libgcrypt"))
7148 Each symbol names a transformation and the corresponding string is an argument
7149 to that transformation.
7152 For instance, a manifest equivalent to this command:
7156 --with-branch=guile-gcrypt=master \
7157 --with-debug-info=zlib
7161 ... would look like this:
7164 (use-modules (guix transformations))
7167 ;; The package transformation procedure.
7168 (options->transformation
7169 '((with-branch . "guile-gcrypt=master")
7170 (with-debug-info . "zlib"))))
7173 (list (transform (specification->package "guix"))))
7176 @cindex input rewriting
7177 @cindex dependency graph rewriting
7178 The @code{options->transformation} procedure is convenient, but it's
7179 perhaps also not as flexible as you may like. How is it implemented?
7180 The astute reader probably noticed that most package transformation
7181 options go beyond the superficial changes shown in the first examples of
7182 this section: they involve @dfn{input rewriting}, whereby the dependency
7183 graph of a package is rewritten by replacing specific inputs by others.
7185 Dependency graph rewriting, for the purposes of swapping packages in the
7186 graph, is what the @code{package-input-rewriting} procedure in
7187 @code{(guix packages)} implements.
7189 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
7190 [@var{rewrite-name}] [#:deep? #t]
7191 Return a procedure that, when passed a package, replaces its direct and
7192 indirect dependencies, including implicit inputs when @var{deep?} is
7193 true, according to @var{replacements}. @var{replacements} is a list of
7194 package pairs; the first element of each pair is the package to replace,
7195 and the second one is the replacement.
7197 Optionally, @var{rewrite-name} is a one-argument procedure that takes
7198 the name of a package and returns its new name after rewrite.
7202 Consider this example:
7205 (define libressl-instead-of-openssl
7206 ;; This is a procedure to replace OPENSSL by LIBRESSL,
7208 (package-input-rewriting `((,openssl . ,libressl))))
7210 (define git-with-libressl
7211 (libressl-instead-of-openssl git))
7215 Here we first define a rewriting procedure that replaces @var{openssl}
7216 with @var{libressl}. Then we use it to define a @dfn{variant} of the
7217 @var{git} package that uses @var{libressl} instead of @var{openssl}.
7218 This is exactly what the @option{--with-input} command-line option does
7219 (@pxref{Package Transformation Options, @option{--with-input}}).
7221 The following variant of @code{package-input-rewriting} can match packages to
7222 be replaced by name rather than by identity.
7224 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements} [#:deep? #t]
7225 Return a procedure that, given a package, applies the given
7226 @var{replacements} to all the package graph, including implicit inputs
7227 unless @var{deep?} is false. @var{replacements} is a list of
7228 spec/procedures pair; each spec is a package specification such as
7229 @code{"gcc"} or @code{"guile@@2"}, and each procedure takes a matching
7230 package and returns a replacement for that package.
7233 The example above could be rewritten this way:
7236 (define libressl-instead-of-openssl
7237 ;; Replace all the packages called "openssl" with LibreSSL.
7238 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
7241 The key difference here is that, this time, packages are matched by spec and
7242 not by identity. In other words, any package in the graph that is called
7243 @code{openssl} will be replaced.
7245 A more generic procedure to rewrite a package dependency graph is
7246 @code{package-mapping}: it supports arbitrary changes to nodes in the
7249 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}] [#:deep? #f]
7250 Return a procedure that, given a package, applies @var{proc} to all the packages
7251 depended on and returns the resulting package. The procedure stops recursion
7252 when @var{cut?} returns true for a given package. When @var{deep?} is true, @var{proc} is
7253 applied to implicit inputs as well.
7258 @section Build Systems
7260 @cindex build system
7261 Each package definition specifies a @dfn{build system} and arguments for
7262 that build system (@pxref{Defining Packages}). This @code{build-system}
7263 field represents the build procedure of the package, as well as implicit
7264 dependencies of that build procedure.
7266 Build systems are @code{<build-system>} objects. The interface to
7267 create and manipulate them is provided by the @code{(guix build-system)}
7268 module, and actual build systems are exported by specific modules.
7270 @cindex bag (low-level package representation)
7271 Under the hood, build systems first compile package objects to
7272 @dfn{bags}. A @dfn{bag} is like a package, but with less
7273 ornamentation---in other words, a bag is a lower-level representation of
7274 a package, which includes all the inputs of that package, including some
7275 that were implicitly added by the build system. This intermediate
7276 representation is then compiled to a derivation (@pxref{Derivations}).
7277 The @code{package-with-c-toolchain} is an example of a way to change the
7278 implicit inputs that a package's build system pulls in (@pxref{package
7279 Reference, @code{package-with-c-toolchain}}).
7281 Build systems accept an optional list of @dfn{arguments}. In package
7282 definitions, these are passed @i{via} the @code{arguments} field
7283 (@pxref{Defining Packages}). They are typically keyword arguments
7284 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
7285 Guile Reference Manual}). The value of these arguments is usually
7286 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
7287 by the daemon (@pxref{Derivations}).
7289 The main build system is @code{gnu-build-system}, which implements the
7290 standard build procedure for GNU and many other packages. It
7291 is provided by the @code{(guix build-system gnu)} module.
7293 @defvr {Scheme Variable} gnu-build-system
7294 @code{gnu-build-system} represents the GNU Build System, and variants
7295 thereof (@pxref{Configuration, configuration and makefile conventions,,
7296 standards, GNU Coding Standards}).
7298 @cindex build phases
7299 In a nutshell, packages using it are configured, built, and installed with
7300 the usual @code{./configure && make && make check && make install}
7301 command sequence. In practice, a few additional steps are often needed.
7302 All these steps are split up in separate @dfn{phases}.
7303 @xref{Build Phases}, for more info on build phases and ways to customize
7306 In addition, this build system ensures that the ``standard'' environment
7307 for GNU packages is available. This includes tools such as GCC, libc,
7308 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
7309 build-system gnu)} module for a complete list). We call these the
7310 @dfn{implicit inputs} of a package, because package definitions do not
7311 have to mention them.
7313 This build system supports a number of keyword arguments, which can be
7314 passed @i{via} the @code{arguments} field of a package. Here are some
7315 of the main parameters:
7319 This argument specifies build-side code that evaluates to an alist of
7320 build phases. @xref{Build Phases}, for more information.
7322 @item #:configure-flags
7323 This is a list of flags (strings) passed to the @command{configure}
7324 script. @xref{Defining Packages}, for an example.
7327 This list of strings contains flags passed as arguments to
7328 @command{make} invocations in the @code{build}, @code{check}, and
7329 @code{install} phases.
7331 @item #:out-of-source?
7332 This Boolean, @code{#f} by default, indicates whether to run builds in a
7333 build directory separate from the source tree.
7335 When it is true, the @code{configure} phase creates a separate build
7336 directory, changes to that directory, and runs the @code{configure}
7337 script from there. This is useful for packages that require it, such as
7341 This Boolean, @code{#t} by default, indicates whether the @code{check}
7342 phase should run the package's test suite.
7345 This string, @code{"check"} by default, gives the name of the makefile
7346 target used by the @code{check} phase.
7348 @item #:parallel-build?
7349 @itemx #:parallel-tests?
7350 These Boolean values specify whether to build, respectively run the test
7351 suite, in parallel, with the @code{-j} flag of @command{make}. When
7352 they are true, @code{make} is passed @code{-j@var{n}}, where @var{n} is
7353 the number specified as the @option{--cores} option of
7354 @command{guix-daemon} or that of the @command{guix} client command
7355 (@pxref{Common Build Options, @option{--cores}}).
7357 @cindex RUNPATH, validation
7358 @item #:validate-runpath?
7359 This Boolean, @code{#t} by default, determines whether to ``validate''
7360 the @code{RUNPATH} of ELF binaries (@code{.so} shared libraries as well
7361 as executables) previously installed by the @code{install} phase.
7363 This validation step consists in making sure that all the shared
7364 libraries needed by an ELF binaries, which are listed as
7365 @code{DT_NEEDED} entries in its @code{PT_DYNAMIC} segment, appear in the
7366 @code{DT_RUNPATH} entry of that binary. In other words, it ensures that
7367 running or using those binaries will not result in a ``file not found''
7368 error at run time. @xref{Options, @option{-rpath},, ld, The GNU
7369 Linker}, for more information on @code{RUNPATH}.
7371 @item #:substitutable?
7372 This Boolean, @code{#t} by default, tells whether the package outputs
7373 should be substitutable---i.e., whether users should be able to obtain
7374 substitutes for them instead of building locally (@pxref{Substitutes}).
7376 @item #:allowed-references
7377 @itemx #:disallowed-references
7378 When true, these arguments must be a list of dependencies that must not
7379 appear among the references of the build results. If, upon build
7380 completion, some of these references are retained, the build process
7383 This is useful to ensure that a package does not erroneously keep a
7384 reference to some of it build-time inputs, in cases where doing so
7385 would, for example, unnecessarily increase its size (@pxref{Invoking
7389 Most other build systems support these keyword arguments.
7392 Other @code{<build-system>} objects are defined to support other
7393 conventions and tools used by free software packages. They inherit most
7394 of @code{gnu-build-system}, and differ mainly in the set of inputs
7395 implicitly added to the build process, and in the list of phases
7396 executed. Some of these build systems are listed below.
7398 @defvr {Scheme Variable} ant-build-system
7399 This variable is exported by @code{(guix build-system ant)}. It
7400 implements the build procedure for Java packages that can be built with
7401 @url{https://ant.apache.org/, Ant build tool}.
7403 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
7404 provided by the @code{icedtea} package to the set of inputs. Different
7405 packages can be specified with the @code{#:ant} and @code{#:jdk}
7406 parameters, respectively.
7408 When the original package does not provide a suitable Ant build file,
7409 the parameter @code{#:jar-name} can be used to generate a minimal Ant
7410 build file @file{build.xml} with tasks to build the specified jar
7411 archive. In this case the parameter @code{#:source-dir} can be used to
7412 specify the source sub-directory, defaulting to ``src''.
7414 The @code{#:main-class} parameter can be used with the minimal ant
7415 buildfile to specify the main class of the resulting jar. This makes the
7416 jar file executable. The @code{#:test-include} parameter can be used to
7417 specify the list of junit tests to run. It defaults to
7418 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
7419 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
7420 because abstract classes cannot be run as tests.
7422 The parameter @code{#:build-target} can be used to specify the Ant task
7423 that should be run during the @code{build} phase. By default the
7424 ``jar'' task will be run.
7428 @defvr {Scheme Variable} android-ndk-build-system
7429 @cindex Android distribution
7430 @cindex Android NDK build system
7431 This variable is exported by @code{(guix build-system android-ndk)}. It
7432 implements a build procedure for Android NDK (native development kit)
7433 packages using a Guix-specific build process.
7435 The build system assumes that packages install their public interface
7436 (header) files to the subdirectory @file{include} of the @code{out} output and
7437 their libraries to the subdirectory @file{lib} the @code{out} output.
7439 It's also assumed that the union of all the dependencies of a package
7440 has no conflicting files.
7442 For the time being, cross-compilation is not supported - so right now
7443 the libraries and header files are assumed to be host tools.
7447 @defvr {Scheme Variable} asdf-build-system/source
7448 @defvrx {Scheme Variable} asdf-build-system/sbcl
7449 @defvrx {Scheme Variable} asdf-build-system/ecl
7451 These variables, exported by @code{(guix build-system asdf)}, implement
7452 build procedures for Common Lisp packages using
7453 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
7454 definition facility for Common Lisp programs and libraries.
7456 The @code{asdf-build-system/source} system installs the packages in
7457 source form, and can be loaded using any common lisp implementation, via
7458 ASDF@. The others, such as @code{asdf-build-system/sbcl}, install binary
7459 systems in the format which a particular implementation understands.
7460 These build systems can also be used to produce executable programs, or
7461 lisp images which contain a set of packages pre-loaded.
7463 The build system uses naming conventions. For binary packages, the
7464 package name should be prefixed with the lisp implementation, such as
7465 @code{sbcl-} for @code{asdf-build-system/sbcl}.
7467 Additionally, the corresponding source package should be labeled using
7468 the same convention as python packages (see @ref{Python Modules}), using
7469 the @code{cl-} prefix.
7471 In order to create executable programs and images, the build-side
7472 procedures @code{build-program} and @code{build-image} can be used.
7473 They should be called in a build phase after the
7474 @code{create-asdf-configuration} phase, so that the system which was
7475 just built can be used within the resulting image. @code{build-program}
7476 requires a list of Common Lisp expressions to be passed as the
7477 @code{#:entry-program} argument.
7479 By default, all the @file{.asd} files present in the sources are read to
7480 find system definitions. The @code{#:asd-files} parameter can be used
7481 to specify the list of @file{.asd} files to read. Furthermore, if the
7482 package defines a system for its tests in a separate file, it will be
7483 loaded before the tests are run if it is specified by the
7484 @code{#:test-asd-file} parameter. If it is not set, the files
7485 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
7486 and @code{test.asd} will be tried if they exist.
7488 If for some reason the package must be named in a different way than the
7489 naming conventions suggest, or if several systems must be compiled, the
7490 @code{#:asd-systems} parameter can be used to specify the list of system
7495 @defvr {Scheme Variable} cargo-build-system
7496 @cindex Rust programming language
7497 @cindex Cargo (Rust build system)
7498 This variable is exported by @code{(guix build-system cargo)}. It
7499 supports builds of packages using Cargo, the build tool of the
7500 @uref{https://www.rust-lang.org, Rust programming language}.
7502 It adds @code{rustc} and @code{cargo} to the set of inputs.
7503 A different Rust package can be specified with the @code{#:rust} parameter.
7505 Regular cargo dependencies should be added to the package definition similarly
7506 to other packages; those needed only at build time to native-inputs, others to
7507 inputs. If you need to add source-only crates then you should add them to via
7508 the @code{#:cargo-inputs} parameter as a list of name and spec pairs, where the
7509 spec can be a package or a source definition. Note that the spec must
7510 evaluate to a path to a gzipped tarball which includes a @code{Cargo.toml}
7511 file at its root, or it will be ignored. Similarly, cargo dev-dependencies
7512 should be added to the package definition via the
7513 @code{#:cargo-development-inputs} parameter.
7515 In its @code{configure} phase, this build system will make any source inputs
7516 specified in the @code{#:cargo-inputs} and @code{#:cargo-development-inputs}
7517 parameters available to cargo. It will also remove an included
7518 @code{Cargo.lock} file to be recreated by @code{cargo} during the
7519 @code{build} phase. The @code{package} phase will run @code{cargo package}
7520 to create a source crate for future use. The @code{install} phase installs
7521 the binaries defined by the crate. Unless @code{install-source? #f} is
7522 defined it will also install a source crate repository of itself and unpacked
7523 sources, to ease in future hacking on rust packages.
7526 @defvr {Scheme Variable} chicken-build-system
7527 This variable is exported by @code{(guix build-system chicken)}. It
7528 builds @uref{https://call-cc.org/, CHICKEN Scheme} modules, also called
7529 ``eggs'' or ``extensions''. CHICKEN generates C source code, which then
7530 gets compiled by a C compiler, in this case GCC.
7532 This build system adds @code{chicken} to the package inputs, as well as
7533 the packages of @code{gnu-build-system}.
7535 The build system can't (yet) deduce the egg's name automatically, so just like
7536 with @code{go-build-system} and its @code{#:import-path}, you should define
7537 @code{#:egg-name} in the package's @code{arguments} field.
7539 For example, if you are packaging the @code{srfi-1} egg:
7542 (arguments '(#:egg-name "srfi-1"))
7545 Egg dependencies must be defined in @code{propagated-inputs}, not @code{inputs}
7546 because CHICKEN doesn't embed absolute references in compiled eggs.
7547 Test dependencies should go to @code{native-inputs}, as usual.
7550 @defvr {Scheme Variable} copy-build-system
7551 This variable is exported by @code{(guix build-system copy)}. It
7552 supports builds of simple packages that don't require much compiling,
7553 mostly just moving files around.
7555 It adds much of the @code{gnu-build-system} packages to the set of
7556 inputs. Because of this, the @code{copy-build-system} does not require
7557 all the boilerplate code often needed for the
7558 @code{trivial-build-system}.
7560 To further simplify the file installation process, an
7561 @code{#:install-plan} argument is exposed to let the packager specify
7562 which files go where. The install plan is a list of @code{(@var{source}
7563 @var{target} [@var{filters}])}. @var{filters} are optional.
7566 @item When @var{source} matches a file or directory without trailing slash, install it to @var{target}.
7568 @item If @var{target} has a trailing slash, install @var{source} basename beneath @var{target}.
7569 @item Otherwise install @var{source} as @var{target}.
7572 @item When @var{source} is a directory with a trailing slash, or when @var{filters} are used,
7573 the trailing slash of @var{target} is implied with the same meaning
7576 @item Without @var{filters}, install the full @var{source} @emph{content} to @var{target}.
7577 @item With @var{filters} among @code{#:include}, @code{#:include-regexp}, @code{#:exclude},
7578 @code{#:exclude-regexp}, only select files are installed depending on
7579 the filters. Each filters is specified by a list of strings.
7581 @item With @code{#:include}, install all the files which the path suffix matches
7582 at least one of the elements in the given list.
7583 @item With @code{#:include-regexp}, install all the files which the
7584 subpaths match at least one of the regular expressions in the given
7586 @item The @code{#:exclude} and @code{#:exclude-regexp} filters
7587 are the complement of their inclusion counterpart. Without @code{#:include} flags,
7588 install all files but those matching the exclusion filters.
7589 If both inclusions and exclusions are specified, the exclusions are done
7590 on top of the inclusions.
7593 In all cases, the paths relative to @var{source} are preserved within
7600 @item @code{("foo/bar" "share/my-app/")}: Install @file{bar} to @file{share/my-app/bar}.
7601 @item @code{("foo/bar" "share/my-app/baz")}: Install @file{bar} to @file{share/my-app/baz}.
7602 @item @code{("foo/" "share/my-app")}: Install the content of @file{foo} inside @file{share/my-app},
7603 e.g., install @file{foo/sub/file} to @file{share/my-app/sub/file}.
7604 @item @code{("foo/" "share/my-app" #:include ("sub/file"))}: Install only @file{foo/sub/file} to
7605 @file{share/my-app/sub/file}.
7606 @item @code{("foo/sub" "share/my-app" #:include ("file"))}: Install @file{foo/sub/file} to
7607 @file{share/my-app/file}.
7612 @cindex Clojure (programming language)
7613 @cindex simple Clojure build system
7614 @defvr {Scheme Variable} clojure-build-system
7615 This variable is exported by @code{(guix build-system clojure)}. It implements
7616 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
7617 using plain old @code{compile} in Clojure. Cross-compilation is not supported
7620 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
7621 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
7622 @code{#:zip} parameters, respectively.
7624 A list of source directories, test directories and jar names can be specified
7625 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
7626 parameters, respectively. Compile directory and main class can be specified
7627 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
7628 Other parameters are documented below.
7630 This build system is an extension of @code{ant-build-system}, but with the
7631 following phases changed:
7636 This phase calls @code{compile} in Clojure to compile source files and runs
7637 @command{jar} to create jars from both source files and compiled files
7638 according to the include list and exclude list specified in
7639 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
7640 has priority over the include list. These lists consist of symbols
7641 representing Clojure libraries or the special keyword @code{#:all} representing
7642 all Clojure libraries found under the source directories. The parameter
7643 @code{#:omit-source?} decides if source should be included into the jars.
7646 This phase runs tests according to the include list and exclude list specified
7647 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
7648 meanings are analogous to that of @code{#:aot-include} and
7649 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
7650 stands for all Clojure libraries found under the test directories. The
7651 parameter @code{#:tests?} decides if tests should be run.
7654 This phase installs all jars built previously.
7657 Apart from the above, this build system also contains an additional phase:
7662 This phase installs all top-level files with base name matching
7663 @code{%doc-regex}. A different regex can be specified with the
7664 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
7665 directories specified in @code{#:doc-dirs} are installed as well.
7669 @defvr {Scheme Variable} cmake-build-system
7670 This variable is exported by @code{(guix build-system cmake)}. It
7671 implements the build procedure for packages using the
7672 @url{https://www.cmake.org, CMake build tool}.
7674 It automatically adds the @code{cmake} package to the set of inputs.
7675 Which package is used can be specified with the @code{#:cmake}
7678 The @code{#:configure-flags} parameter is taken as a list of flags
7679 passed to the @command{cmake} command. The @code{#:build-type}
7680 parameter specifies in abstract terms the flags passed to the compiler;
7681 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
7682 debugging information''), which roughly means that code is compiled with
7683 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
7686 @defvr {Scheme Variable} dune-build-system
7687 This variable is exported by @code{(guix build-system dune)}. It
7688 supports builds of packages using @uref{https://dune.build/, Dune}, a build
7689 tool for the OCaml programming language. It is implemented as an extension
7690 of the @code{ocaml-build-system} which is described below. As such, the
7691 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
7694 It automatically adds the @code{dune} package to the set of inputs.
7695 Which package is used can be specified with the @code{#:dune}
7698 There is no @code{configure} phase because dune packages typically don't
7699 need to be configured. The @code{#:build-flags} parameter is taken as a
7700 list of flags passed to the @code{dune} command during the build.
7702 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
7703 command instead of the more recent @code{dune} command while building
7704 a package. Its default value is @code{#f}.
7706 The @code{#:package} parameter can be passed to specify a package name, which
7707 is useful when a package contains multiple packages and you want to build
7708 only one of them. This is equivalent to passing the @code{-p} argument to
7712 @defvr {Scheme Variable} go-build-system
7713 This variable is exported by @code{(guix build-system go)}. It
7714 implements a build procedure for Go packages using the standard
7715 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
7716 Go build mechanisms}.
7718 The user is expected to provide a value for the key @code{#:import-path}
7719 and, in some cases, @code{#:unpack-path}. The
7720 @url{https://golang.org/doc/code.html#ImportPaths, import path}
7721 corresponds to the file system path expected by the package's build
7722 scripts and any referring packages, and provides a unique way to
7723 refer to a Go package. It is typically based on a combination of the
7724 package source code's remote URI and file system hierarchy structure. In
7725 some cases, you will need to unpack the package's source code to a
7726 different directory structure than the one indicated by the import path,
7727 and @code{#:unpack-path} should be used in such cases.
7729 Packages that provide Go libraries should install their source code into
7730 the built output. The key @code{#:install-source?}, which defaults to
7731 @code{#t}, controls whether or not the source code is installed. It can
7732 be set to @code{#f} for packages that only provide executable files.
7735 @defvr {Scheme Variable} glib-or-gtk-build-system
7736 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
7737 is intended for use with packages making use of GLib or GTK+.
7739 This build system adds the following two phases to the ones defined by
7740 @code{gnu-build-system}:
7743 @item glib-or-gtk-wrap
7744 The phase @code{glib-or-gtk-wrap} ensures that programs in
7745 @file{bin/} are able to find GLib ``schemas'' and
7746 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
7747 modules}. This is achieved by wrapping the programs in launch scripts
7748 that appropriately set the @env{XDG_DATA_DIRS} and @env{GTK_PATH}
7749 environment variables.
7751 It is possible to exclude specific package outputs from that wrapping
7752 process by listing their names in the
7753 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
7754 when an output is known not to contain any GLib or GTK+ binaries, and
7755 where wrapping would gratuitously add a dependency of that output on
7758 @item glib-or-gtk-compile-schemas
7759 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
7760 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
7761 GSettings schemas} of GLib are compiled. Compilation is performed by the
7762 @command{glib-compile-schemas} program. It is provided by the package
7763 @code{glib:bin} which is automatically imported by the build system.
7764 The @code{glib} package providing @command{glib-compile-schemas} can be
7765 specified with the @code{#:glib} parameter.
7768 Both phases are executed after the @code{install} phase.
7771 @defvr {Scheme Variable} guile-build-system
7772 This build system is for Guile packages that consist exclusively of Scheme
7773 code and that are so lean that they don't even have a makefile, let alone a
7774 @file{configure} script. It compiles Scheme code using @command{guild
7775 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
7776 installs the @file{.scm} and @file{.go} files in the right place. It also
7777 installs documentation.
7779 This build system supports cross-compilation by using the
7780 @option{--target} option of @samp{guild compile}.
7782 Packages built with @code{guile-build-system} must provide a Guile package in
7783 their @code{native-inputs} field.
7786 @defvr {Scheme Variable} julia-build-system
7787 This variable is exported by @code{(guix build-system julia)}. It
7788 implements the build procedure used by @uref{https://julialang.org/,
7789 julia} packages, which essentially is similar to running @samp{julia -e
7790 'using Pkg; Pkg.add(package)'} in an environment where
7791 @env{JULIA_LOAD_PATH} contains the paths to all Julia package inputs.
7792 Tests are run by calling @code{/test/runtests.jl}.
7794 The Julia package name is read from the file @file{Project.toml}. This
7795 value can be overridden by passing the argument @code{#:julia-package-name}
7796 (which must be correctly capitalized).
7798 Julia packages usually manage their binary dependencies via
7799 @code{JLLWrappers.jl}, a Julia package that creates a module (named
7800 after the wrapped library followed by @code{_jll.jl}.
7802 To add the binary path @code{_jll.jl} packages, you need to patch the
7803 files under @file{src/wrappers/}, replacing the call to the macro
7804 @code{JLLWrappers.@@generate_wrapper_header}, adding as a second
7805 argument containing the store path the binary.
7807 As an example, in the MbedTLS Julia package, we add a build phase
7808 (@pxref{Build Phases}) to insert the absolute file name of the wrapped
7812 (add-after 'unpack 'override-binary-path
7813 (lambda* (#:key inputs #:allow-other-keys)
7814 (for-each (lambda (wrapper)
7815 (substitute* wrapper
7816 (("generate_wrapper_header.*")
7818 "generate_wrapper_header(\"MbedTLS\", \""
7819 (assoc-ref inputs "mbedtls-apache") "\")\n"))))
7820 ;; There's a Julia file for each platform, override them all.
7821 (find-files "src/wrappers/" "\\.jl$"))))
7824 Some older packages that aren't using @file{Package.toml} yet, will require
7825 this file to be created, too. The function @code{julia-create-package-toml}
7826 helps creating the file. You need to pass the outputs and the source of the
7827 package, it's name (the same as the @code{file-name} parameter), the package
7828 uuid, the package version, and a list of dependencies specified by their name
7832 @defvr {Scheme Variable} maven-build-system
7833 This variable is exported by @code{(guix build-system maven)}. It implements
7834 a build procedure for @uref{https://maven.apache.org, Maven} packages. Maven
7835 is a dependency and lifecycle management tool for Java. A user of Maven
7836 specifies dependencies and plugins in a @file{pom.xml} file that Maven reads.
7837 When Maven does not have one of the dependencies or plugins in its repository,
7838 it will download them and use them to build the package.
7840 The maven build system ensures that maven will not try to download any
7841 dependency by running in offline mode. Maven will fail if a dependency is
7842 missing. Before running Maven, the @file{pom.xml} (and subprojects) are
7843 modified to specify the version of dependencies and plugins that match the
7844 versions available in the guix build environment. Dependencies and plugins
7845 must be installed in the fake maven repository at @file{lib/m2}, and are
7846 symlinked into a proper repository before maven is run. Maven is instructed
7847 to use that repository for the build and installs built artifacts there.
7848 Changed files are copied to the @file{lib/m2} directory of the package output.
7850 You can specify a @file{pom.xml} file with the @code{#:pom-file} argument,
7851 or let the build system use the default @file{pom.xml} file in the sources.
7853 In case you need to specify a dependency's version manually, you can use the
7854 @code{#:local-packages} argument. It takes an association list where the key
7855 is the groupId of the package and its value is an association list where the
7856 key is the artifactId of the package and its value is the version you want to
7857 override in the @file{pom.xml}.
7859 Some packages use dependencies or plugins that are not useful at runtime nor
7860 at build time in Guix. You can alter the @file{pom.xml} file to remove them
7861 using the @code{#:exclude} argument. Its value is an association list where
7862 the key is the groupId of the plugin or dependency you want to remove, and
7863 the value is a list of artifactId you want to remove.
7865 You can override the default @code{jdk} and @code{maven} packages with the
7866 corresponding argument, @code{#:jdk} and @code{#:maven}.
7868 The @code{#:maven-plugins} argument is a list of maven plugins used during
7869 the build, with the same format as the @code{inputs} fields of the package
7870 declaration. Its default value is @code{(default-maven-plugins)} which is
7874 @defvr {Scheme Variable} minify-build-system
7875 This variable is exported by @code{(guix build-system minify)}. It
7876 implements a minification procedure for simple JavaScript packages.
7878 It adds @code{uglify-js} to the set of inputs and uses it to compress
7879 all JavaScript files in the @file{src} directory. A different minifier
7880 package can be specified with the @code{#:uglify-js} parameter, but it
7881 is expected that the package writes the minified code to the standard
7884 When the input JavaScript files are not all located in the @file{src}
7885 directory, the parameter @code{#:javascript-files} can be used to
7886 specify a list of file names to feed to the minifier.
7889 @defvr {Scheme Variable} ocaml-build-system
7890 This variable is exported by @code{(guix build-system ocaml)}. It implements
7891 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
7892 of choosing the correct set of commands to run for each package. OCaml
7893 packages can expect many different commands to be run. This build system will
7896 When the package has a @file{setup.ml} file present at the top-level, it will
7897 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
7898 @code{ocaml setup.ml -install}. The build system will assume that this file
7899 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
7900 care of setting the prefix and enabling tests if they are not disabled. You
7901 can pass configure and build flags with the @code{#:configure-flags} and
7902 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
7903 set of flags used to enable tests. The @code{#:use-make?} key can be used to
7904 bypass this system in the build and install phases.
7906 When the package has a @file{configure} file, it is assumed that it is a
7907 hand-made configure script that requires a different argument format than
7908 in the @code{gnu-build-system}. You can add more flags with the
7909 @code{#:configure-flags} key.
7911 When the package has a @file{Makefile} file (or @code{#:use-make?} is
7912 @code{#t}), it will be used and more flags can be passed to the build and
7913 install phases with the @code{#:make-flags} key.
7915 Finally, some packages do not have these files and use a somewhat standard
7916 location for its build system. In that case, the build system will run
7917 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
7918 providing the path to the required findlib module. Additional flags can
7919 be passed via the @code{#:build-flags} key. Install is taken care of by
7920 @command{opam-installer}. In this case, the @code{opam} package must
7921 be added to the @code{native-inputs} field of the package definition.
7923 Note that most OCaml packages assume they will be installed in the same
7924 directory as OCaml, which is not what we want in guix. In particular, they
7925 will install @file{.so} files in their module's directory, which is usually
7926 fine because it is in the OCaml compiler directory. In guix though, these
7927 libraries cannot be found and we use @env{CAML_LD_LIBRARY_PATH}. This
7928 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
7929 @file{.so} libraries should be installed.
7932 @defvr {Scheme Variable} python-build-system
7933 This variable is exported by @code{(guix build-system python)}. It
7934 implements the more or less standard build procedure used by Python
7935 packages, which consists in running @code{python setup.py build} and
7936 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
7938 For packages that install stand-alone Python programs under @code{bin/},
7939 it takes care of wrapping these programs so that their @env{PYTHONPATH}
7940 environment variable points to all the Python libraries they depend on.
7942 Which Python package is used to perform the build can be specified with
7943 the @code{#:python} parameter. This is a useful way to force a package
7944 to be built for a specific version of the Python interpreter, which
7945 might be necessary if the package is only compatible with a single
7946 interpreter version.
7948 By default guix calls @code{setup.py} under control of
7949 @code{setuptools}, much like @command{pip} does. Some packages are not
7950 compatible with setuptools (and pip), thus you can disable this by
7951 setting the @code{#:use-setuptools?} parameter to @code{#f}.
7954 @defvr {Scheme Variable} perl-build-system
7955 This variable is exported by @code{(guix build-system perl)}. It
7956 implements the standard build procedure for Perl packages, which either
7957 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
7958 followed by @code{Build} and @code{Build install}; or in running
7959 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
7960 @code{make} and @code{make install}, depending on which of
7961 @code{Build.PL} or @code{Makefile.PL} is present in the package
7962 distribution. Preference is given to the former if both @code{Build.PL}
7963 and @code{Makefile.PL} exist in the package distribution. This
7964 preference can be reversed by specifying @code{#t} for the
7965 @code{#:make-maker?} parameter.
7967 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
7968 passes flags specified by the @code{#:make-maker-flags} or
7969 @code{#:module-build-flags} parameter, respectively.
7971 Which Perl package is used can be specified with @code{#:perl}.
7974 @defvr {Scheme Variable} renpy-build-system
7975 This variable is exported by @code{(guix build-system renpy)}. It implements
7976 the more or less standard build procedure used by Ren'py games, which consists
7977 of loading @code{#:game} once, thereby creating bytecode for it.
7979 It further creates a wrapper script in @code{bin/} and a desktop entry in
7980 @code{share/applications}, both of which can be used to launch the game.
7982 Which Ren'py package is used can be specified with @code{#:renpy}.
7983 Games can also be installed in outputs other than ``out'' by using
7987 @defvr {Scheme Variable} qt-build-system
7988 This variable is exported by @code{(guix build-system qt)}. It
7989 is intended for use with applications using Qt or KDE.
7991 This build system adds the following two phases to the ones defined by
7992 @code{cmake-build-system}:
7996 The phase @code{check-setup} prepares the environment for running
7997 the checks as commonly used by Qt test programs.
7998 For now this only sets some environment variables:
7999 @code{QT_QPA_PLATFORM=offscreen},
8000 @code{DBUS_FATAL_WARNINGS=0} and
8001 @code{CTEST_OUTPUT_ON_FAILURE=1}.
8003 This phase is added before the @code{check} phase.
8004 It's a separate phase to ease adjusting if necessary.
8007 The phase @code{qt-wrap}
8008 searches for Qt5 plugin paths, QML paths and some XDG in the inputs
8009 and output. In case some path is found, all programs in the output's
8010 @file{bin/}, @file{sbin/}, @file{libexec/} and @file{lib/libexec/} directories
8011 are wrapped in scripts defining the necessary environment variables.
8013 It is possible to exclude specific package outputs from that wrapping process
8014 by listing their names in the @code{#:qt-wrap-excluded-outputs} parameter.
8015 This is useful when an output is known not to contain any Qt binaries, and
8016 where wrapping would gratuitously add a dependency of that output on Qt, KDE,
8019 This phase is added after the @code{install} phase.
8023 @defvr {Scheme Variable} r-build-system
8024 This variable is exported by @code{(guix build-system r)}. It
8025 implements the build procedure used by @uref{https://r-project.org, R}
8026 packages, which essentially is little more than running @samp{R CMD
8027 INSTALL --library=/gnu/store/@dots{}} in an environment where
8028 @env{R_LIBS_SITE} contains the paths to all R package inputs. Tests are
8029 run after installation using the R function
8030 @code{tools::testInstalledPackage}.
8033 @defvr {Scheme Variable} rakudo-build-system
8034 This variable is exported by @code{(guix build-system rakudo)}. It
8035 implements the build procedure used by @uref{https://rakudo.org/,
8036 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
8037 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
8038 installs the binaries, library files and the resources, as well as wrap
8039 the files under the @code{bin/} directory. Tests can be skipped by
8040 passing @code{#f} to the @code{tests?} parameter.
8042 Which rakudo package is used can be specified with @code{rakudo}.
8043 Which perl6-tap-harness package used for the tests can be specified with
8044 @code{#:prove6} or removed by passing @code{#f} to the
8045 @code{with-prove6?} parameter.
8046 Which perl6-zef package used for tests and installing can be specified
8047 with @code{#:zef} or removed by passing @code{#f} to the
8048 @code{with-zef?} parameter.
8051 @defvr {Scheme Variable} texlive-build-system
8052 This variable is exported by @code{(guix build-system texlive)}. It is
8053 used to build TeX packages in batch mode with a specified engine. The
8054 build system sets the @env{TEXINPUTS} variable to find all TeX source
8055 files in the inputs.
8057 By default it runs @code{luatex} on all files ending on @code{ins}. A
8058 different engine and format can be specified with the
8059 @code{#:tex-format} argument. Different build targets can be specified
8060 with the @code{#:build-targets} argument, which expects a list of file
8061 names. The build system adds only @code{texlive-bin} and
8062 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
8063 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
8064 and @code{#:texlive-latex-base}, respectively.
8066 The @code{#:tex-directory} parameter tells the build system where to
8067 install the built files under the texmf tree.
8070 @defvr {Scheme Variable} ruby-build-system
8071 This variable is exported by @code{(guix build-system ruby)}. It
8072 implements the RubyGems build procedure used by Ruby packages, which
8073 involves running @code{gem build} followed by @code{gem install}.
8075 The @code{source} field of a package that uses this build system
8076 typically references a gem archive, since this is the format that Ruby
8077 developers use when releasing their software. The build system unpacks
8078 the gem archive, potentially patches the source, runs the test suite,
8079 repackages the gem, and installs it. Additionally, directories and
8080 tarballs may be referenced to allow building unreleased gems from Git or
8081 a traditional source release tarball.
8083 Which Ruby package is used can be specified with the @code{#:ruby}
8084 parameter. A list of additional flags to be passed to the @command{gem}
8085 command can be specified with the @code{#:gem-flags} parameter.
8088 @defvr {Scheme Variable} waf-build-system
8089 This variable is exported by @code{(guix build-system waf)}. It
8090 implements a build procedure around the @code{waf} script. The common
8091 phases---@code{configure}, @code{build}, and @code{install}---are
8092 implemented by passing their names as arguments to the @code{waf}
8095 The @code{waf} script is executed by the Python interpreter. Which
8096 Python package is used to run the script can be specified with the
8097 @code{#:python} parameter.
8100 @defvr {Scheme Variable} scons-build-system
8101 This variable is exported by @code{(guix build-system scons)}. It
8102 implements the build procedure used by the SCons software construction
8103 tool. This build system runs @code{scons} to build the package,
8104 @code{scons test} to run tests, and then @code{scons install} to install
8107 Additional flags to be passed to @code{scons} can be specified with the
8108 @code{#:scons-flags} parameter. The default build and install targets
8109 can be overridden with @code{#:build-targets} and
8110 @code{#:install-targets} respectively. The version of Python used to
8111 run SCons can be specified by selecting the appropriate SCons package
8112 with the @code{#:scons} parameter.
8115 @defvr {Scheme Variable} haskell-build-system
8116 This variable is exported by @code{(guix build-system haskell)}. It
8117 implements the Cabal build procedure used by Haskell packages, which
8118 involves running @code{runhaskell Setup.hs configure
8119 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
8120 Instead of installing the package by running @code{runhaskell Setup.hs
8121 install}, to avoid trying to register libraries in the read-only
8122 compiler store directory, the build system uses @code{runhaskell
8123 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
8124 addition, the build system generates the package documentation by
8125 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
8126 is passed. Optional Haddock parameters can be passed with the help of
8127 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
8128 not found, the build system looks for @code{Setup.lhs} instead.
8130 Which Haskell compiler is used can be specified with the @code{#:haskell}
8131 parameter which defaults to @code{ghc}.
8134 @defvr {Scheme Variable} dub-build-system
8135 This variable is exported by @code{(guix build-system dub)}. It
8136 implements the Dub build procedure used by D packages, which
8137 involves running @code{dub build} and @code{dub run}.
8138 Installation is done by copying the files manually.
8140 Which D compiler is used can be specified with the @code{#:ldc}
8141 parameter which defaults to @code{ldc}.
8144 @anchor{emacs-build-system}
8145 @defvr {Scheme Variable} emacs-build-system
8146 This variable is exported by @code{(guix build-system emacs)}. It
8147 implements an installation procedure similar to the packaging system
8148 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
8150 It first creates the @code{@code{package}-autoloads.el} file, then it
8151 byte compiles all Emacs Lisp files. Differently from the Emacs
8152 packaging system, the Info documentation files are moved to the standard
8153 documentation directory and the @file{dir} file is deleted. The Elisp
8154 package files are installed directly under @file{share/emacs/site-lisp}.
8157 @defvr {Scheme Variable} font-build-system
8158 This variable is exported by @code{(guix build-system font)}. It
8159 implements an installation procedure for font packages where upstream
8160 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
8161 need to be copied into place. It copies font files to standard
8162 locations in the output directory.
8165 @defvr {Scheme Variable} meson-build-system
8166 This variable is exported by @code{(guix build-system meson)}. It
8167 implements the build procedure for packages that use
8168 @url{https://mesonbuild.com, Meson} as their build system.
8170 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
8171 of inputs, and they can be changed with the parameters @code{#:meson}
8172 and @code{#:ninja} if needed. The default Meson is
8173 @code{meson-for-build}, which is special because it doesn't clear the
8174 @code{RUNPATH} of binaries and libraries when they are installed.
8176 This build system is an extension of @code{gnu-build-system}, but with the
8177 following phases changed to some specific for Meson:
8182 The phase runs @code{meson} with the flags specified in
8183 @code{#:configure-flags}. The flag @option{--buildtype} is always set to
8184 @code{debugoptimized} unless something else is specified in
8185 @code{#:build-type}.
8188 The phase runs @code{ninja} to build the package in parallel by default, but
8189 this can be changed with @code{#:parallel-build?}.
8192 The phase runs @code{ninja} with the target specified in @code{#:test-target},
8193 which is @code{"test"} by default.
8196 The phase runs @code{ninja install} and can not be changed.
8199 Apart from that, the build system also adds the following phases:
8204 This phase ensures that all binaries can find the libraries they need.
8205 It searches for required libraries in subdirectories of the package being
8206 built, and adds those to @code{RUNPATH} where needed. It also removes
8207 references to libraries left over from the build phase by
8208 @code{meson-for-build}, such as test dependencies, that aren't actually
8209 required for the program to run.
8211 @item glib-or-gtk-wrap
8212 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
8213 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
8215 @item glib-or-gtk-compile-schemas
8216 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
8217 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
8221 @defvr {Scheme Variable} linux-module-build-system
8222 @code{linux-module-build-system} allows building Linux kernel modules.
8224 @cindex build phases
8225 This build system is an extension of @code{gnu-build-system}, but with the
8226 following phases changed:
8231 This phase configures the environment so that the Linux kernel's Makefile
8232 can be used to build the external kernel module.
8235 This phase uses the Linux kernel's Makefile in order to build the external
8239 This phase uses the Linux kernel's Makefile in order to install the external
8243 It is possible and useful to specify the Linux kernel to use for building
8244 the module (in the @code{arguments} form of a package using the
8245 @code{linux-module-build-system}, use the key @code{#:linux} to specify it).
8248 @defvr {Scheme Variable} node-build-system
8249 This variable is exported by @code{(guix build-system node)}. It
8250 implements the build procedure used by @uref{https://nodejs.org,
8251 Node.js}, which implements an approximation of the @code{npm install}
8252 command, followed by an @code{npm test} command.
8254 Which Node.js package is used to interpret the @code{npm} commands can
8255 be specified with the @code{#:node} parameter which defaults to
8259 Lastly, for packages that do not need anything as sophisticated, a
8260 ``trivial'' build system is provided. It is trivial in the sense that
8261 it provides basically no support: it does not pull any implicit inputs,
8262 and does not have a notion of build phases.
8264 @defvr {Scheme Variable} trivial-build-system
8265 This variable is exported by @code{(guix build-system trivial)}.
8267 This build system requires a @code{#:builder} argument. This argument
8268 must be a Scheme expression that builds the package output(s)---as
8269 with @code{build-expression->derivation} (@pxref{Derivations,
8270 @code{build-expression->derivation}}).
8274 @section Build Phases
8276 @cindex build phases, for packages
8277 Almost all package build systems implement a notion @dfn{build phases}:
8278 a sequence of actions that the build system executes, when you build the
8279 package, leading to the installed byproducts in the store. A notable
8280 exception is the ``bare-bones'' @code{trivial-build-system}
8281 (@pxref{Build Systems}).
8283 As discussed in the previous section, those build systems provide a
8284 standard list of phases. For @code{gnu-build-system}, the main build
8285 phases are the following:
8289 Unpack the source tarball, and change the current directory to the
8290 extracted source tree. If the source is actually a directory, copy it
8291 to the build tree, and enter that directory.
8293 @item patch-source-shebangs
8294 Patch shebangs encountered in source files so they refer to the right
8295 store file names. For instance, this changes @code{#!/bin/sh} to
8296 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
8299 Run the @file{configure} script with a number of default options, such
8300 as @option{--prefix=/gnu/store/@dots{}}, as well as the options specified
8301 by the @code{#:configure-flags} argument.
8304 Run @code{make} with the list of flags specified with
8305 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
8306 (the default), build with @code{make -j}.
8309 Run @code{make check}, or some other target specified with
8310 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
8311 @code{#:parallel-tests?} argument is true (the default), run @code{make
8315 Run @code{make install} with the flags listed in @code{#:make-flags}.
8317 @item patch-shebangs
8318 Patch shebangs on the installed executable files.
8321 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
8322 is false), copying them to the @code{debug} output when available
8323 (@pxref{Installing Debugging Files}).
8326 Other build systems have similar phases, with some variations. For
8327 example, @code{cmake-build-system} has same-named phases but its
8328 @code{configure} phases runs @code{cmake} instead of @code{./configure}.
8329 Others, such as @code{python-build-system}, have a wholly different list
8330 of standard phases. All this code runs on the @dfn{build side}: it is
8331 evaluated when you actually build the package, in a dedicated build
8332 process spawned by the build daemon (@pxref{Invoking guix-daemon}).
8334 Build phases are represented as association lists or ``alists''
8335 (@pxref{Association Lists,,, guile, GNU Guile Reference Manual}) where
8336 each key is a symbol for the name of the phase and the associated value
8337 is a procedure that accepts an arbitrary number of arguments. By
8338 convention, those procedures receive information about the build in the
8339 form of @dfn{keyword parameters}, which they can use or ignore.
8341 @vindex %standard-phases
8342 For example, here is how @code{(guix build gnu-build-system)} defines
8343 @code{%standard-phases}, the variable holding its alist of build
8344 phases@footnote{We present a simplified view of those build phases, but
8345 do take a look at @code{(guix build gnu-build-system)} to see all the
8349 ;; The build phases of 'gnu-build-system'.
8351 (define* (unpack #:key source #:allow-other-keys)
8352 ;; Extract the source tarball.
8353 (invoke "tar" "xvf" source))
8355 (define* (configure #:key outputs #:allow-other-keys)
8356 ;; Run the 'configure' script. Install to output "out".
8357 (let ((out (assoc-ref outputs "out")))
8358 (invoke "./configure"
8359 (string-append "--prefix=" out))))
8361 (define* (build #:allow-other-keys)
8365 (define* (check #:key (test-target "check") (tests? #true)
8367 ;; Run the test suite.
8369 (invoke "make" test-target)
8370 (display "test suite not run\n")))
8372 (define* (install #:allow-other-keys)
8373 ;; Install files to the prefix 'configure' specified.
8374 (invoke "make" "install"))
8376 (define %standard-phases
8377 ;; The list of standard phases (quite a few are omitted
8378 ;; for brevity). Each element is a symbol/procedure pair.
8379 (list (cons 'unpack unpack)
8380 (cons 'configure configure)
8383 (cons 'install install)))
8386 This shows how @code{%standard-phases} is defined as a list of
8387 symbol/procedure pairs (@pxref{Pairs,,, guile, GNU Guile Reference
8388 Manual}). The first pair associates the @code{unpack} procedure with
8389 the @code{unpack} symbol---a name; the second pair defines the
8390 @code{configure} phase similarly, and so on. When building a package
8391 that uses @code{gnu-build-system} with its default list of phases, those
8392 phases are executed sequentially. You can see the name of each phase
8393 started and completed in the build log of packages that you build.
8395 Let's now look at the procedures themselves. Each one is defined with
8396 @code{define*}: @code{#:key} lists keyword parameters the procedure
8397 accepts, possibly with a default value, and @code{#:allow-other-keys}
8398 specifies that other keyword parameters are ignored (@pxref{Optional
8399 Arguments,,, guile, GNU Guile Reference Manual}).
8401 The @code{unpack} procedure honors the @code{source} parameter, which
8402 the build system uses to pass the file name of the source tarball (or
8403 version control checkout), and it ignores other parameters. The
8404 @code{configure} phase only cares about the @code{outputs} parameter, an
8405 alist mapping package output names to their store file name
8406 (@pxref{Packages with Multiple Outputs}). It extracts the file name of
8407 for @code{out}, the default output, and passes it to
8408 @command{./configure} as the installation prefix, meaning that
8409 @command{make install} will eventually copy all the files in that
8410 directory (@pxref{Configuration, configuration and makefile
8411 conventions,, standards, GNU Coding Standards}). @code{build} and
8412 @code{install} ignore all their arguments. @code{check} honors the
8413 @code{test-target} argument, which specifies the name of the Makefile
8414 target to run tests; it prints a message and skips tests when
8415 @code{tests?} is false.
8417 @cindex build phases, customizing
8418 The list of phases used for a particular package can be changed with the
8419 @code{#:phases} parameter of the build system. Changing the set of
8420 build phases boils down to building a new alist of phases based on the
8421 @code{%standard-phases} alist described above. This can be done with
8422 standard alist procedures such as @code{alist-delete} (@pxref{SRFI-1
8423 Association Lists,,, guile, GNU Guile Reference Manual}); however, it is
8424 more convenient to do so with @code{modify-phases} (@pxref{Build
8425 Utilities, @code{modify-phases}}).
8427 Here is an example of a package definition that removes the
8428 @code{configure} phase of @code{%standard-phases} and inserts a new
8429 phase before the @code{build} phase, called
8430 @code{set-prefix-in-makefile}:
8433 (define-public example
8436 ;; other fields omitted
8437 (build-system gnu-build-system)
8439 '(#:phases (modify-phases %standard-phases
8441 (add-before 'build 'set-prefix-in-makefile
8442 (lambda* (#:key outputs #:allow-other-keys)
8443 ;; Modify the makefile so that its
8444 ;; 'PREFIX' variable points to "out".
8445 (let ((out (assoc-ref outputs "out")))
8446 (substitute* "Makefile"
8448 (string-append "PREFIX = "
8453 The new phase that is inserted is written as an anonymous procedure,
8454 introduced with @code{lambda*}; it honors the @code{outputs} parameter
8455 we have seen before. @xref{Build Utilities}, for more about the helpers
8456 used by this phase, and for more examples of @code{modify-phases}.
8458 @cindex code staging
8459 @cindex staging, of code
8460 Keep in mind that build phases are code evaluated at the time the
8461 package is actually built. This explains why the whole
8462 @code{modify-phases} expression above is quoted (it comes after the
8463 @code{'} or apostrophe): it is @dfn{staged} for later execution.
8464 @xref{G-Expressions}, for an explanation of code staging and the
8465 @dfn{code strata} involved.
8467 @node Build Utilities
8468 @section Build Utilities
8470 As soon as you start writing non-trivial package definitions
8471 (@pxref{Defining Packages}) or other build actions
8472 (@pxref{G-Expressions}), you will likely start looking for helpers for
8473 ``shell-like'' actions---creating directories, copying and deleting
8474 files recursively, manipulating build phases, and so on. The
8475 @code{(guix build utils)} module provides such utility procedures.
8477 Most build systems load @code{(guix build utils)} (@pxref{Build
8478 Systems}). Thus, when writing custom build phases for your package
8479 definitions, you can usually assume those procedures are in scope.
8481 When writing G-expressions, you can import @code{(guix build utils)} on
8482 the ``build side'' using @code{with-imported-modules} and then put it in
8483 scope with the @code{use-modules} form (@pxref{Using Guile Modules,,,
8484 guile, GNU Guile Reference Manual}):
8487 (with-imported-modules '((guix build utils)) ;import it
8488 (computed-file "empty-tree"
8491 (use-modules (guix build utils))
8493 ;; Happily use its 'mkdir-p' procedure.
8494 (mkdir-p (string-append #$output "/a/b/c")))))
8497 The remainder of this section is the reference for most of the utility
8498 procedures provided by @code{(guix build utils)}.
8500 @c TODO Document what's missing.
8502 @subsection Dealing with Store File Names
8504 This section documents procedures that deal with store file names.
8506 @deffn {Scheme Procedure} %store-directory
8507 Return the directory name of the store.
8510 @deffn {Scheme Procedure} store-file-name? @var{file}
8511 Return true if @var{file} is in the store.
8514 @deffn {Scheme Procedure} strip-store-file-name @var{file}
8515 Strip the @file{/gnu/store} and hash from @var{file}, a store file name.
8516 The result is typically a @code{"@var{package}-@var{version}"} string.
8519 @deffn {Scheme Procedure} package-name->name+version @var{name}
8520 Given @var{name}, a package name like @code{"foo-0.9.1b"}, return two
8521 values: @code{"foo"} and @code{"0.9.1b"}. When the version part is
8522 unavailable, @var{name} and @code{#f} are returned. The first hyphen
8523 followed by a digit is considered to introduce the version part.
8526 @subsection File Types
8528 The procedures below deal with files and file types.
8530 @deffn {Scheme Procedure} directory-exists? @var{dir}
8531 Return @code{#t} if @var{dir} exists and is a directory.
8534 @deffn {Scheme Procedure} executable-file? @var{file}
8535 Return @code{#t} if @var{file} exists and is executable.
8538 @deffn {Scheme Procedure} symbolic-link? @var{file}
8539 Return @code{#t} if @var{file} is a symbolic link (aka. a ``symlink'').
8542 @deffn {Scheme Procedure} elf-file? @var{file}
8543 @deffnx {Scheme Procedure} ar-file? @var{file}
8544 @deffnx {Scheme Procedure} gzip-file? @var{file}
8545 Return @code{#t} if @var{file} is, respectively, an ELF file, an
8546 @code{ar} archive (such as a @file{.a} static library), or a gzip file.
8549 @deffn {Scheme Procedure} reset-gzip-timestamp @var{file} [#:keep-mtime? #t]
8550 If @var{file} is a gzip file, reset its embedded timestamp (as with
8551 @command{gzip --no-name}) and return true. Otherwise return @code{#f}.
8552 When @var{keep-mtime?} is true, preserve @var{file}'s modification time.
8555 @subsection File Manipulation
8557 The following procedures and macros help create, modify, and delete
8558 files. They provide functionality comparable to common shell utilities
8559 such as @command{mkdir -p}, @command{cp -r}, @command{rm -r}, and
8560 @command{sed}. They complement Guile's extensive, but low-level, file
8561 system interface (@pxref{POSIX,,, guile, GNU Guile Reference Manual}).
8563 @deffn {Scheme Syntax} with-directory-excursion @var{directory} @var{body}@dots{}
8564 Run @var{body} with @var{directory} as the process's current directory.
8566 Essentially, this macro changes the current directory to @var{directory}
8567 before evaluating @var{body}, using @code{chdir} (@pxref{Processes,,,
8568 guile, GNU Guile Reference Manual}). It changes back to the initial
8569 directory when the dynamic extent of @var{body} is left, be it @i{via}
8570 normal procedure return or @i{via} a non-local exit such as an
8574 @deffn {Scheme Procedure} mkdir-p @var{dir}
8575 Create directory @var{dir} and all its ancestors.
8578 @deffn {Scheme Procedure} install-file @var{file} @var{directory}
8579 Create @var{directory} if it does not exist and copy @var{file} in there
8580 under the same name.
8583 @deffn {Scheme Procedure} make-file-writable @var{file}
8584 Make @var{file} writable for its owner.
8587 @deffn {Scheme Procedure} copy-recursively @var{source} @var{destination} @
8588 [#:log (current-output-port)] [#:follow-symlinks? #f] [#:keep-mtime? #f]
8589 Copy @var{source} directory to @var{destination}. Follow symlinks if
8590 @var{follow-symlinks?} is true; otherwise, just preserve them. When
8591 @var{keep-mtime?} is true, keep the modification time of the files in
8592 @var{source} on those of @var{destination}. Write verbose output to the
8596 @deffn {Scheme Procedure} delete-file-recursively @var{dir} @
8597 [#:follow-mounts? #f]
8598 Delete @var{dir} recursively, like @command{rm -rf}, without following
8599 symlinks. Don't follow mount points either, unless @var{follow-mounts?}
8600 is true. Report but ignore errors.
8603 @deffn {Scheme Syntax} substitute* @var{file} @
8604 ((@var{regexp} @var{match-var}@dots{}) @var{body}@dots{}) @dots{}
8605 Substitute @var{regexp} in @var{file} by the string returned by
8606 @var{body}. @var{body} is evaluated with each @var{match-var} bound to
8607 the corresponding positional regexp sub-expression. For example:
8613 (("foo([a-z]+)bar(.*)$" all letters end)
8614 (string-append "baz" letter end)))
8617 Here, anytime a line of @var{file} contains @code{hello}, it is replaced
8618 by @code{good morning}. Anytime a line of @var{file} matches the second
8619 regexp, @code{all} is bound to the complete match, @code{letters} is bound
8620 to the first sub-expression, and @code{end} is bound to the last one.
8622 When one of the @var{match-var} is @code{_}, no variable is bound to the
8623 corresponding match substring.
8625 Alternatively, @var{file} may be a list of file names, in which case
8626 they are all subject to the substitutions.
8628 Be careful about using @code{$} to match the end of a line; by itself it
8629 won't match the terminating newline of a line.
8632 @subsection File Search
8634 @cindex file, searching
8635 This section documents procedures to search and filter files.
8637 @deffn {Scheme Procedure} file-name-predicate @var{regexp}
8638 Return a predicate that returns true when passed a file name whose base
8639 name matches @var{regexp}.
8642 @deffn {Scheme Procedure} find-files @var{dir} [@var{pred}] @
8643 [#:stat lstat] [#:directories? #f] [#:fail-on-error? #f]
8644 Return the lexicographically sorted list of files under @var{dir} for
8645 which @var{pred} returns true. @var{pred} is passed two arguments: the
8646 absolute file name, and its stat buffer; the default predicate always
8647 returns true. @var{pred} can also be a regular expression, in which
8648 case it is equivalent to @code{(file-name-predicate @var{pred})}.
8649 @var{stat} is used to obtain file information; using @code{lstat} means
8650 that symlinks are not followed. If @var{directories?} is true, then
8651 directories will also be included. If @var{fail-on-error?} is true,
8652 raise an exception upon error.
8655 Here are a few examples where we assume that the current directory is
8656 the root of the Guix source tree:
8659 ;; List all the regular files in the current directory.
8661 @result{} ("./.dir-locals.el" "./.gitignore" @dots{})
8663 ;; List all the .scm files under gnu/services.
8664 (find-files "gnu/services" "\\.scm$")
8665 @result{} ("gnu/services/admin.scm" "gnu/services/audio.scm" @dots{})
8667 ;; List ar files in the current directory.
8668 (find-files "." (lambda (file stat) (ar-file? file)))
8669 @result{} ("./libformat.a" "./libstore.a" @dots{})
8672 @deffn {Scheme Procedure} which @var{program}
8673 Return the complete file name for @var{program} as found in
8674 @code{$PATH}, or @code{#f} if @var{program} could not be found.
8677 @subsection Build Phases
8679 @cindex build phases
8680 The @code{(guix build utils)} also contains tools to manipulate build
8681 phases as used by build systems (@pxref{Build Systems}). Build phases
8682 are represented as association lists or ``alists'' (@pxref{Association
8683 Lists,,, guile, GNU Guile Reference Manual}) where each key is a symbol
8684 naming the phase and the associated value is a procedure (@pxref{Build
8687 Guile core and the @code{(srfi srfi-1)} module both provide tools to
8688 manipulate alists. The @code{(guix build utils)} module complements
8689 those with tools written with build phases in mind.
8691 @cindex build phases, modifying
8692 @deffn {Scheme Syntax} modify-phases @var{phases} @var{clause}@dots{}
8693 Modify @var{phases} sequentially as per each @var{clause}, which may
8694 have one of the following forms:
8697 (delete @var{old-phase-name})
8698 (replace @var{old-phase-name} @var{new-phase})
8699 (add-before @var{old-phase-name} @var{new-phase-name} @var{new-phase})
8700 (add-after @var{old-phase-name} @var{new-phase-name} @var{new-phase})
8703 Where every @var{phase-name} above is an expression evaluating to a
8704 symbol, and @var{new-phase} an expression evaluating to a procedure.
8707 The example below is taken from the definition of the @code{grep}
8708 package. It adds a phase to run after the @code{install} phase, called
8709 @code{fix-egrep-and-fgrep}. That phase is a procedure (@code{lambda*}
8710 is for anonymous procedures) that takes a @code{#:outputs} keyword
8711 argument and ignores extra keyword arguments (@pxref{Optional
8712 Arguments,,, guile, GNU Guile Reference Manual}, for more on
8713 @code{lambda*} and optional and keyword arguments.) The phase uses
8714 @code{substitute*} to modify the installed @file{egrep} and @file{fgrep}
8715 scripts so that they refer to @code{grep} by its absolute file name:
8718 (modify-phases %standard-phases
8719 (add-after 'install 'fix-egrep-and-fgrep
8720 ;; Patch 'egrep' and 'fgrep' to execute 'grep' via its
8721 ;; absolute file name instead of searching for it in $PATH.
8722 (lambda* (#:key outputs #:allow-other-keys)
8723 (let* ((out (assoc-ref outputs "out"))
8724 (bin (string-append out "/bin")))
8725 (substitute* (list (string-append bin "/egrep")
8726 (string-append bin "/fgrep"))
8728 (string-append "exec " bin "/grep")))
8732 In the example below, phases are modified in two ways: the standard
8733 @code{configure} phase is deleted, presumably because the package does
8734 not have a @file{configure} script or anything similar, and the default
8735 @code{install} phase is replaced by one that manually copies the
8736 executable files to be installed:
8739 (modify-phases %standard-phases
8740 (delete 'configure) ;no 'configure' script
8742 (lambda* (#:key outputs #:allow-other-keys)
8743 ;; The package's Makefile doesn't provide an "install"
8744 ;; rule so do it by ourselves.
8745 (let ((bin (string-append (assoc-ref outputs "out")
8747 (install-file "footswitch" bin)
8748 (install-file "scythe" bin)
8752 @c TODO: Add more examples.
8761 Conceptually, the @dfn{store} is the place where derivations that have
8762 been built successfully are stored---by default, @file{/gnu/store}.
8763 Sub-directories in the store are referred to as @dfn{store items} or
8764 sometimes @dfn{store paths}. The store has an associated database that
8765 contains information such as the store paths referred to by each store
8766 path, and the list of @emph{valid} store items---results of successful
8767 builds. This database resides in @file{@var{localstatedir}/guix/db},
8768 where @var{localstatedir} is the state directory specified @i{via}
8769 @option{--localstatedir} at configure time, usually @file{/var}.
8771 The store is @emph{always} accessed by the daemon on behalf of its clients
8772 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
8773 connect to the daemon over a Unix-domain socket, send requests to it,
8774 and read the result---these are remote procedure calls, or RPCs.
8777 Users must @emph{never} modify files under @file{/gnu/store} directly.
8778 This would lead to inconsistencies and break the immutability
8779 assumptions of Guix's functional model (@pxref{Introduction}).
8781 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
8782 how to check the integrity of the store and attempt recovery from
8783 accidental modifications.
8786 The @code{(guix store)} module provides procedures to connect to the
8787 daemon, and to perform RPCs. These are described below. By default,
8788 @code{open-connection}, and thus all the @command{guix} commands,
8789 connect to the local daemon or to the URI specified by the
8790 @env{GUIX_DAEMON_SOCKET} environment variable.
8792 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
8793 When set, the value of this variable should be a file name or a URI
8794 designating the daemon endpoint. When it is a file name, it denotes a
8795 Unix-domain socket to connect to. In addition to file names, the
8796 supported URI schemes are:
8801 These are for Unix-domain sockets.
8802 @code{file:///var/guix/daemon-socket/socket} is equivalent to
8803 @file{/var/guix/daemon-socket/socket}.
8806 @cindex daemon, remote access
8807 @cindex remote access to the daemon
8808 @cindex daemon, cluster setup
8809 @cindex clusters, daemon setup
8810 These URIs denote connections over TCP/IP, without encryption nor
8811 authentication of the remote host. The URI must specify the host name
8812 and optionally a port number (by default port 44146 is used):
8815 guix://master.guix.example.org:1234
8818 This setup is suitable on local networks, such as clusters, where only
8819 trusted nodes may connect to the build daemon at
8820 @code{master.guix.example.org}.
8822 The @option{--listen} option of @command{guix-daemon} can be used to
8823 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
8824 @option{--listen}}).
8827 @cindex SSH access to build daemons
8828 These URIs allow you to connect to a remote daemon over SSH@. This
8829 feature requires Guile-SSH (@pxref{Requirements}) and a working
8830 @command{guile} binary in @env{PATH} on the destination machine. It
8831 supports public key and GSSAPI authentication. A typical URL might look
8835 ssh://charlie@@guix.example.org:22
8838 As for @command{guix copy}, the usual OpenSSH client configuration files
8839 are honored (@pxref{Invoking guix copy}).
8842 Additional URI schemes may be supported in the future.
8844 @c XXX: Remove this note when the protocol incurs fewer round trips
8845 @c and when (guix derivations) no longer relies on file system access.
8847 The ability to connect to remote build daemons is considered
8848 experimental as of @value{VERSION}. Please get in touch with us to
8849 share any problems or suggestions you may have (@pxref{Contributing}).
8853 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
8854 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
8855 @var{reserve-space?} is true, instruct it to reserve a little bit of
8856 extra space on the file system so that the garbage collector can still
8857 operate should the disk become full. Return a server object.
8859 @var{file} defaults to @code{%default-socket-path}, which is the normal
8860 location given the options that were passed to @command{configure}.
8863 @deffn {Scheme Procedure} close-connection @var{server}
8864 Close the connection to @var{server}.
8867 @defvr {Scheme Variable} current-build-output-port
8868 This variable is bound to a SRFI-39 parameter, which refers to the port
8869 where build and error logs sent by the daemon should be written.
8872 Procedures that make RPCs all take a server object as their first
8875 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
8876 @cindex invalid store items
8877 Return @code{#t} when @var{path} designates a valid store item and
8878 @code{#f} otherwise (an invalid item may exist on disk but still be
8879 invalid, for instance because it is the result of an aborted or failed
8882 A @code{&store-protocol-error} condition is raised if @var{path} is not
8883 prefixed by the store directory (@file{/gnu/store}).
8886 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
8887 Add @var{text} under file @var{name} in the store, and return its store
8888 path. @var{references} is the list of store paths referred to by the
8889 resulting store path.
8892 @deffn {Scheme Procedure} build-derivations @var{store} @var{derivations} @
8894 Build @var{derivations}, a list of @code{<derivation>} objects, @file{.drv}
8895 file names, or derivation/output pairs, using the specified
8896 @var{mode}---@code{(build-mode normal)} by default.
8899 Note that the @code{(guix monads)} module provides a monad as well as
8900 monadic versions of the above procedures, with the goal of making it
8901 more convenient to work with code that accesses the store (@pxref{The
8905 @i{This section is currently incomplete.}
8908 @section Derivations
8911 Low-level build actions and the environment in which they are performed
8912 are represented by @dfn{derivations}. A derivation contains the
8913 following pieces of information:
8917 The outputs of the derivation---derivations produce at least one file or
8918 directory in the store, but may produce more.
8921 @cindex build-time dependencies
8922 @cindex dependencies, build-time
8923 The inputs of the derivations---i.e., its build-time dependencies---which may
8924 be other derivations or plain files in the store (patches, build scripts,
8928 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
8931 The file name of a build script in the store, along with the arguments
8935 A list of environment variables to be defined.
8939 @cindex derivation path
8940 Derivations allow clients of the daemon to communicate build actions to
8941 the store. They exist in two forms: as an in-memory representation,
8942 both on the client- and daemon-side, and as files in the store whose
8943 name end in @file{.drv}---these files are referred to as @dfn{derivation
8944 paths}. Derivations paths can be passed to the @code{build-derivations}
8945 procedure to perform the build actions they prescribe (@pxref{The
8948 @cindex fixed-output derivations
8949 Operations such as file downloads and version-control checkouts for
8950 which the expected content hash is known in advance are modeled as
8951 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
8952 of a fixed-output derivation are independent of its inputs---e.g., a
8953 source code download produces the same result regardless of the download
8954 method and tools being used.
8957 @cindex run-time dependencies
8958 @cindex dependencies, run-time
8959 The outputs of derivations---i.e., the build results---have a set of
8960 @dfn{references}, as reported by the @code{references} RPC or the
8961 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
8962 are the set of run-time dependencies of the build results. References are a
8963 subset of the inputs of the derivation; this subset is automatically computed
8964 by the build daemon by scanning all the files in the outputs.
8966 The @code{(guix derivations)} module provides a representation of
8967 derivations as Scheme objects, along with procedures to create and
8968 otherwise manipulate derivations. The lowest-level primitive to create
8969 a derivation is the @code{derivation} procedure:
8971 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
8972 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
8973 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
8974 [#:system (%current-system)] [#:references-graphs #f] @
8975 [#:allowed-references #f] [#:disallowed-references #f] @
8976 [#:leaked-env-vars #f] [#:local-build? #f] @
8977 [#:substitutable? #t] [#:properties '()]
8978 Build a derivation with the given arguments, and return the resulting
8979 @code{<derivation>} object.
8981 When @var{hash} and @var{hash-algo} are given, a
8982 @dfn{fixed-output derivation} is created---i.e., one whose result is
8983 known in advance, such as a file download. If, in addition,
8984 @var{recursive?} is true, then that fixed output may be an executable
8985 file or a directory and @var{hash} must be the hash of an archive
8986 containing this output.
8988 When @var{references-graphs} is true, it must be a list of file
8989 name/store path pairs. In that case, the reference graph of each store
8990 path is exported in the build environment in the corresponding file, in
8991 a simple text format.
8993 When @var{allowed-references} is true, it must be a list of store items
8994 or outputs that the derivation's output may refer to. Likewise,
8995 @var{disallowed-references}, if true, must be a list of things the
8996 outputs may @emph{not} refer to.
8998 When @var{leaked-env-vars} is true, it must be a list of strings
8999 denoting environment variables that are allowed to ``leak'' from the
9000 daemon's environment to the build environment. This is only applicable
9001 to fixed-output derivations---i.e., when @var{hash} is true. The main
9002 use is to allow variables such as @code{http_proxy} to be passed to
9003 derivations that download files.
9005 When @var{local-build?} is true, declare that the derivation is not a
9006 good candidate for offloading and should rather be built locally
9007 (@pxref{Daemon Offload Setup}). This is the case for small derivations
9008 where the costs of data transfers would outweigh the benefits.
9010 When @var{substitutable?} is false, declare that substitutes of the
9011 derivation's output should not be used (@pxref{Substitutes}). This is
9012 useful, for instance, when building packages that capture details of the
9013 host CPU instruction set.
9015 @var{properties} must be an association list describing ``properties'' of the
9016 derivation. It is kept as-is, uninterpreted, in the derivation.
9020 Here's an example with a shell script as its builder, assuming
9021 @var{store} is an open connection to the daemon, and @var{bash} points
9022 to a Bash executable in the store:
9025 (use-modules (guix utils)
9029 (let ((builder ; add the Bash script to the store
9030 (add-text-to-store store "my-builder.sh"
9031 "echo hello world > $out\n" '())))
9032 (derivation store "foo"
9033 bash `("-e" ,builder)
9034 #:inputs `((,bash) (,builder))
9035 #:env-vars '(("HOME" . "/homeless"))))
9036 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
9039 As can be guessed, this primitive is cumbersome to use directly. A
9040 better approach is to write build scripts in Scheme, of course! The
9041 best course of action for that is to write the build code as a
9042 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
9043 information, @pxref{G-Expressions}.
9045 Once upon a time, @code{gexp->derivation} did not exist and constructing
9046 derivations with build code written in Scheme was achieved with
9047 @code{build-expression->derivation}, documented below. This procedure
9048 is now deprecated in favor of the much nicer @code{gexp->derivation}.
9050 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
9051 @var{name} @var{exp} @
9052 [#:system (%current-system)] [#:inputs '()] @
9053 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
9054 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
9055 [#:references-graphs #f] [#:allowed-references #f] @
9056 [#:disallowed-references #f] @
9057 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
9058 Return a derivation that executes Scheme expression @var{exp} as a
9059 builder for derivation @var{name}. @var{inputs} must be a list of
9060 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
9061 @code{"out"} is assumed. @var{modules} is a list of names of Guile
9062 modules from the current search path to be copied in the store,
9063 compiled, and made available in the load path during the execution of
9064 @var{exp}---e.g., @code{((guix build utils) (guix build
9065 gnu-build-system))}.
9067 @var{exp} is evaluated in an environment where @code{%outputs} is bound
9068 to a list of output/path pairs, and where @code{%build-inputs} is bound
9069 to a list of string/output-path pairs made from @var{inputs}.
9070 Optionally, @var{env-vars} is a list of string pairs specifying the name
9071 and value of environment variables visible to the builder. The builder
9072 terminates by passing the result of @var{exp} to @code{exit}; thus, when
9073 @var{exp} returns @code{#f}, the build is considered to have failed.
9075 @var{exp} is built using @var{guile-for-build} (a derivation). When
9076 @var{guile-for-build} is omitted or is @code{#f}, the value of the
9077 @code{%guile-for-build} fluid is used instead.
9079 See the @code{derivation} procedure for the meaning of
9080 @var{references-graphs}, @var{allowed-references},
9081 @var{disallowed-references}, @var{local-build?}, and
9082 @var{substitutable?}.
9086 Here's an example of a single-output derivation that creates a directory
9087 containing one file:
9090 (let ((builder '(let ((out (assoc-ref %outputs "out")))
9091 (mkdir out) ; create /gnu/store/@dots{}-goo
9092 (call-with-output-file (string-append out "/test")
9094 (display '(hello guix) p))))))
9095 (build-expression->derivation store "goo" builder))
9097 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
9101 @node The Store Monad
9102 @section The Store Monad
9106 The procedures that operate on the store described in the previous
9107 sections all take an open connection to the build daemon as their first
9108 argument. Although the underlying model is functional, they either have
9109 side effects or depend on the current state of the store.
9111 The former is inconvenient: the connection to the build daemon has to be
9112 carried around in all those functions, making it impossible to compose
9113 functions that do not take that parameter with functions that do. The
9114 latter can be problematic: since store operations have side effects
9115 and/or depend on external state, they have to be properly sequenced.
9117 @cindex monadic values
9118 @cindex monadic functions
9119 This is where the @code{(guix monads)} module comes in. This module
9120 provides a framework for working with @dfn{monads}, and a particularly
9121 useful monad for our uses, the @dfn{store monad}. Monads are a
9122 construct that allows two things: associating ``context'' with values
9123 (in our case, the context is the store), and building sequences of
9124 computations (here computations include accesses to the store). Values
9125 in a monad---values that carry this additional context---are called
9126 @dfn{monadic values}; procedures that return such values are called
9127 @dfn{monadic procedures}.
9129 Consider this ``normal'' procedure:
9132 (define (sh-symlink store)
9133 ;; Return a derivation that symlinks the 'bash' executable.
9134 (let* ((drv (package-derivation store bash))
9135 (out (derivation->output-path drv))
9136 (sh (string-append out "/bin/bash")))
9137 (build-expression->derivation store "sh"
9138 `(symlink ,sh %output))))
9141 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
9142 as a monadic function:
9145 (define (sh-symlink)
9146 ;; Same, but return a monadic value.
9147 (mlet %store-monad ((drv (package->derivation bash)))
9148 (gexp->derivation "sh"
9149 #~(symlink (string-append #$drv "/bin/bash")
9153 There are several things to note in the second version: the @code{store}
9154 parameter is now implicit and is ``threaded'' in the calls to the
9155 @code{package->derivation} and @code{gexp->derivation} monadic
9156 procedures, and the monadic value returned by @code{package->derivation}
9157 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
9159 As it turns out, the call to @code{package->derivation} can even be
9160 omitted since it will take place implicitly, as we will see later
9161 (@pxref{G-Expressions}):
9164 (define (sh-symlink)
9165 (gexp->derivation "sh"
9166 #~(symlink (string-append #$bash "/bin/bash")
9171 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
9172 @c for the funny quote.
9173 Calling the monadic @code{sh-symlink} has no effect. As someone once
9174 said, ``you exit a monad like you exit a building on fire: by running''.
9175 So, to exit the monad and get the desired effect, one must use
9176 @code{run-with-store}:
9179 (run-with-store (open-connection) (sh-symlink))
9180 @result{} /gnu/store/...-sh-symlink
9183 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
9184 new ``meta-commands'' to make it easier to deal with monadic procedures:
9185 @code{run-in-store}, and @code{enter-store-monad}. The former is used
9186 to ``run'' a single monadic value through the store:
9189 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
9190 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
9193 The latter enters a recursive REPL, where all the return values are
9194 automatically run through the store:
9197 scheme@@(guile-user)> ,enter-store-monad
9198 store-monad@@(guile-user) [1]> (package->derivation hello)
9199 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
9200 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
9201 $3 = "/gnu/store/@dots{}-foo"
9202 store-monad@@(guile-user) [1]> ,q
9203 scheme@@(guile-user)>
9207 Note that non-monadic values cannot be returned in the
9208 @code{store-monad} REPL.
9210 The main syntactic forms to deal with monads in general are provided by
9211 the @code{(guix monads)} module and are described below.
9213 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
9214 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
9218 @deffn {Scheme Syntax} return @var{val}
9219 Return a monadic value that encapsulates @var{val}.
9222 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
9223 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
9224 procedures @var{mproc}@dots{}@footnote{This operation is commonly
9225 referred to as ``bind'', but that name denotes an unrelated procedure in
9226 Guile. Thus we use this somewhat cryptic symbol inherited from the
9227 Haskell language.}. There can be one @var{mproc} or several of them, as
9232 (with-monad %state-monad
9234 (lambda (x) (return (+ 1 x)))
9235 (lambda (x) (return (* 2 x)))))
9239 @result{} some-state
9243 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
9245 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
9247 Bind the variables @var{var} to the monadic values @var{mval} in
9248 @var{body}, which is a sequence of expressions. As with the bind
9249 operator, this can be thought of as ``unpacking'' the raw, non-monadic
9250 value ``contained'' in @var{mval} and making @var{var} refer to that
9251 raw, non-monadic value within the scope of the @var{body}. The form
9252 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
9253 @var{val}, as per @code{let}. The binding operations occur in sequence
9254 from left to right. The last expression of @var{body} must be a monadic
9255 expression, and its result will become the result of the @code{mlet} or
9256 @code{mlet*} when run in the @var{monad}.
9258 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
9259 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
9262 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
9263 Bind @var{mexp} and the following monadic expressions in sequence,
9264 returning the result of the last expression. Every expression in the
9265 sequence must be a monadic expression.
9267 This is akin to @code{mlet}, except that the return values of the
9268 monadic expressions are ignored. In that sense, it is analogous to
9269 @code{begin}, but applied to monadic expressions.
9272 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
9273 When @var{condition} is true, evaluate the sequence of monadic
9274 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
9275 @var{condition} is false, return @code{*unspecified*} in the current
9276 monad. Every expression in the sequence must be a monadic expression.
9279 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
9280 When @var{condition} is false, evaluate the sequence of monadic
9281 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
9282 @var{condition} is true, return @code{*unspecified*} in the current
9283 monad. Every expression in the sequence must be a monadic expression.
9287 The @code{(guix monads)} module provides the @dfn{state monad}, which
9288 allows an additional value---the state---to be @emph{threaded} through
9289 monadic procedure calls.
9291 @defvr {Scheme Variable} %state-monad
9292 The state monad. Procedures in the state monad can access and change
9293 the state that is threaded.
9295 Consider the example below. The @code{square} procedure returns a value
9296 in the state monad. It returns the square of its argument, but also
9297 increments the current state value:
9301 (mlet %state-monad ((count (current-state)))
9302 (mbegin %state-monad
9303 (set-current-state (+ 1 count))
9306 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
9311 When ``run'' through @code{%state-monad}, we obtain that additional state
9312 value, which is the number of @code{square} calls.
9315 @deffn {Monadic Procedure} current-state
9316 Return the current state as a monadic value.
9319 @deffn {Monadic Procedure} set-current-state @var{value}
9320 Set the current state to @var{value} and return the previous state as a
9324 @deffn {Monadic Procedure} state-push @var{value}
9325 Push @var{value} to the current state, which is assumed to be a list,
9326 and return the previous state as a monadic value.
9329 @deffn {Monadic Procedure} state-pop
9330 Pop a value from the current state and return it as a monadic value.
9331 The state is assumed to be a list.
9334 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
9335 Run monadic value @var{mval} starting with @var{state} as the initial
9336 state. Return two values: the resulting value, and the resulting state.
9339 The main interface to the store monad, provided by the @code{(guix
9340 store)} module, is as follows.
9342 @defvr {Scheme Variable} %store-monad
9343 The store monad---an alias for @code{%state-monad}.
9345 Values in the store monad encapsulate accesses to the store. When its
9346 effect is needed, a value of the store monad must be ``evaluated'' by
9347 passing it to the @code{run-with-store} procedure (see below).
9350 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
9351 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
9352 open store connection.
9355 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
9356 Return as a monadic value the absolute file name in the store of the file
9357 containing @var{text}, a string. @var{references} is a list of store items that the
9358 resulting text file refers to; it defaults to the empty list.
9361 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
9362 Return as a monadic value the absolute file name in the store of the file
9363 containing @var{data}, a bytevector. @var{references} is a list of store
9364 items that the resulting binary file refers to; it defaults to the empty list.
9367 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
9368 [#:recursive? #t] [#:select? (const #t)]
9369 Return the name of @var{file} once interned in the store. Use
9370 @var{name} as its store name, or the basename of @var{file} if
9371 @var{name} is omitted.
9373 When @var{recursive?} is true, the contents of @var{file} are added
9374 recursively; if @var{file} designates a flat file and @var{recursive?}
9375 is true, its contents are added, and its permission bits are kept.
9377 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
9378 @var{stat})} for each directory entry, where @var{file} is the entry's
9379 absolute file name and @var{stat} is the result of @code{lstat}; exclude
9380 entries for which @var{select?} does not return true.
9382 The example below adds a file to the store, under two different names:
9385 (run-with-store (open-connection)
9386 (mlet %store-monad ((a (interned-file "README"))
9387 (b (interned-file "README" "LEGU-MIN")))
9388 (return (list a b))))
9390 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
9395 The @code{(guix packages)} module exports the following package-related
9398 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
9399 [#:system (%current-system)] [#:target #f] @
9402 value in the absolute file name of @var{file} within the @var{output}
9403 directory of @var{package}. When @var{file} is omitted, return the name
9404 of the @var{output} directory of @var{package}. When @var{target} is
9405 true, use it as a cross-compilation target triplet.
9407 Note that this procedure does @emph{not} build @var{package}. Thus, the
9408 result might or might not designate an existing file. We recommend not
9409 using this procedure unless you know what you are doing.
9412 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
9413 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
9414 @var{target} [@var{system}]
9415 Monadic version of @code{package-derivation} and
9416 @code{package-cross-derivation} (@pxref{Defining Packages}).
9421 @section G-Expressions
9423 @cindex G-expression
9424 @cindex build code quoting
9425 So we have ``derivations'', which represent a sequence of build actions
9426 to be performed to produce an item in the store (@pxref{Derivations}).
9427 These build actions are performed when asking the daemon to actually
9428 build the derivations; they are run by the daemon in a container
9429 (@pxref{Invoking guix-daemon}).
9431 @cindex code staging
9432 @cindex staging, of code
9433 @cindex strata of code
9434 It should come as no surprise that we like to write these build actions
9435 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
9436 code@footnote{The term @dfn{stratum} in this context was coined by
9437 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
9438 Kiselyov, who has written insightful
9439 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
9440 on this topic}, refers to this kind of code generation as
9441 @dfn{staging}.}: the ``host code''---code that defines packages, talks
9442 to the daemon, etc.---and the ``build code''---code that actually
9443 performs build actions, such as making directories, invoking
9444 @command{make}, and so on (@pxref{Build Phases}).
9446 To describe a derivation and its build actions, one typically needs to
9447 embed build code inside host code. It boils down to manipulating build
9448 code as data, and the homoiconicity of Scheme---code has a direct
9449 representation as data---comes in handy for that. But we need more than
9450 the normal @code{quasiquote} mechanism in Scheme to construct build
9453 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
9454 S-expressions adapted to build expressions. G-expressions, or
9455 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
9456 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
9457 @code{#$}, and @code{#$@@}), which are comparable to
9458 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
9459 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
9460 GNU Guile Reference Manual}). However, there are major differences:
9464 Gexps are meant to be written to a file and run or manipulated by other
9468 When a high-level object such as a package or derivation is unquoted
9469 inside a gexp, the result is as if its output file name had been
9473 Gexps carry information about the packages or derivations they refer to,
9474 and these dependencies are automatically added as inputs to the build
9475 processes that use them.
9478 @cindex lowering, of high-level objects in gexps
9479 This mechanism is not limited to package and derivation
9480 objects: @dfn{compilers} able to ``lower'' other high-level objects to
9481 derivations or files in the store can be defined,
9482 such that these objects can also be inserted
9483 into gexps. For example, a useful type of high-level objects that can be
9484 inserted in a gexp is ``file-like objects'', which make it easy to
9485 add files to the store and to refer to them in
9486 derivations and such (see @code{local-file} and @code{plain-file}
9489 To illustrate the idea, here is an example of a gexp:
9496 (symlink (string-append #$coreutils "/bin/ls")
9500 This gexp can be passed to @code{gexp->derivation}; we obtain a
9501 derivation that builds a directory containing exactly one symlink to
9502 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
9505 (gexp->derivation "the-thing" build-exp)
9508 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
9509 substituted to the reference to the @var{coreutils} package in the
9510 actual build code, and @var{coreutils} is automatically made an input to
9511 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
9512 output)}) is replaced by a string containing the directory name of the
9513 output of the derivation.
9515 @cindex cross compilation
9516 In a cross-compilation context, it is useful to distinguish between
9517 references to the @emph{native} build of a package---that can run on the
9518 host---versus references to cross builds of a package. To that end, the
9519 @code{#+} plays the same role as @code{#$}, but is a reference to a
9520 native package build:
9523 (gexp->derivation "vi"
9526 (mkdir (string-append #$output "/bin"))
9527 (system* (string-append #+coreutils "/bin/ln")
9529 (string-append #$emacs "/bin/emacs")
9530 (string-append #$output "/bin/vi")))
9531 #:target "aarch64-linux-gnu")
9535 In the example above, the native build of @var{coreutils} is used, so
9536 that @command{ln} can actually run on the host; but then the
9537 cross-compiled build of @var{emacs} is referenced.
9539 @cindex imported modules, for gexps
9540 @findex with-imported-modules
9541 Another gexp feature is @dfn{imported modules}: sometimes you want to be
9542 able to use certain Guile modules from the ``host environment'' in the
9543 gexp, so those modules should be imported in the ``build environment''.
9544 The @code{with-imported-modules} form allows you to express that:
9547 (let ((build (with-imported-modules '((guix build utils))
9549 (use-modules (guix build utils))
9550 (mkdir-p (string-append #$output "/bin"))))))
9551 (gexp->derivation "empty-dir"
9554 (display "success!\n")
9559 In this example, the @code{(guix build utils)} module is automatically
9560 pulled into the isolated build environment of our gexp, such that
9561 @code{(use-modules (guix build utils))} works as expected.
9563 @cindex module closure
9564 @findex source-module-closure
9565 Usually you want the @emph{closure} of the module to be imported---i.e.,
9566 the module itself and all the modules it depends on---rather than just
9567 the module; failing to do that, attempts to use the module will fail
9568 because of missing dependent modules. The @code{source-module-closure}
9569 procedure computes the closure of a module by looking at its source file
9570 headers, which comes in handy in this case:
9573 (use-modules (guix modules)) ;for 'source-module-closure'
9575 (with-imported-modules (source-module-closure
9576 '((guix build utils)
9578 (gexp->derivation "something-with-vms"
9580 (use-modules (guix build utils)
9585 @cindex extensions, for gexps
9586 @findex with-extensions
9587 In the same vein, sometimes you want to import not just pure-Scheme
9588 modules, but also ``extensions'' such as Guile bindings to C libraries
9589 or other ``full-blown'' packages. Say you need the @code{guile-json}
9590 package available on the build side, here's how you would do it:
9593 (use-modules (gnu packages guile)) ;for 'guile-json'
9595 (with-extensions (list guile-json)
9596 (gexp->derivation "something-with-json"
9598 (use-modules (json))
9602 The syntactic form to construct gexps is summarized below.
9604 @deffn {Scheme Syntax} #~@var{exp}
9605 @deffnx {Scheme Syntax} (gexp @var{exp})
9606 Return a G-expression containing @var{exp}. @var{exp} may contain one
9607 or more of the following forms:
9611 @itemx (ungexp @var{obj})
9612 Introduce a reference to @var{obj}. @var{obj} may have one of the
9613 supported types, for example a package or a
9614 derivation, in which case the @code{ungexp} form is replaced by its
9615 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
9617 If @var{obj} is a list, it is traversed and references to supported
9618 objects are substituted similarly.
9620 If @var{obj} is another gexp, its contents are inserted and its
9621 dependencies are added to those of the containing gexp.
9623 If @var{obj} is another kind of object, it is inserted as is.
9625 @item #$@var{obj}:@var{output}
9626 @itemx (ungexp @var{obj} @var{output})
9627 This is like the form above, but referring explicitly to the
9628 @var{output} of @var{obj}---this is useful when @var{obj} produces
9629 multiple outputs (@pxref{Packages with Multiple Outputs}).
9632 @itemx #+@var{obj}:output
9633 @itemx (ungexp-native @var{obj})
9634 @itemx (ungexp-native @var{obj} @var{output})
9635 Same as @code{ungexp}, but produces a reference to the @emph{native}
9636 build of @var{obj} when used in a cross compilation context.
9638 @item #$output[:@var{output}]
9639 @itemx (ungexp output [@var{output}])
9640 Insert a reference to derivation output @var{output}, or to the main
9641 output when @var{output} is omitted.
9643 This only makes sense for gexps passed to @code{gexp->derivation}.
9646 @itemx (ungexp-splicing @var{lst})
9647 Like the above, but splices the contents of @var{lst} inside the
9651 @itemx (ungexp-native-splicing @var{lst})
9652 Like the above, but refers to native builds of the objects listed in
9657 G-expressions created by @code{gexp} or @code{#~} are run-time objects
9658 of the @code{gexp?} type (see below).
9661 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
9662 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
9663 in their execution environment.
9665 Each item in @var{modules} can be the name of a module, such as
9666 @code{(guix build utils)}, or it can be a module name, followed by an
9667 arrow, followed by a file-like object:
9670 `((guix build utils)
9672 ((guix config) => ,(scheme-file "config.scm"
9673 #~(define-module @dots{}))))
9677 In the example above, the first two modules are taken from the search
9678 path, and the last one is created from the given file-like object.
9680 This form has @emph{lexical} scope: it has an effect on the gexps
9681 directly defined in @var{body}@dots{}, but not on those defined, say, in
9682 procedures called from @var{body}@dots{}.
9685 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
9686 Mark the gexps defined in @var{body}@dots{} as requiring
9687 @var{extensions} in their build and execution environment.
9688 @var{extensions} is typically a list of package objects such as those
9689 defined in the @code{(gnu packages guile)} module.
9691 Concretely, the packages listed in @var{extensions} are added to the
9692 load path while compiling imported modules in @var{body}@dots{}; they
9693 are also added to the load path of the gexp returned by
9697 @deffn {Scheme Procedure} gexp? @var{obj}
9698 Return @code{#t} if @var{obj} is a G-expression.
9701 G-expressions are meant to be written to disk, either as code building
9702 some derivation, or as plain files in the store. The monadic procedures
9703 below allow you to do that (@pxref{The Store Monad}, for more
9704 information about monads).
9706 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
9707 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
9708 [#:hash #f] [#:hash-algo #f] @
9709 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
9710 [#:module-path @code{%load-path}] @
9711 [#:effective-version "2.2"] @
9712 [#:references-graphs #f] [#:allowed-references #f] @
9713 [#:disallowed-references #f] @
9714 [#:leaked-env-vars #f] @
9715 [#:script-name (string-append @var{name} "-builder")] @
9716 [#:deprecation-warnings #f] @
9717 [#:local-build? #f] [#:substitutable? #t] @
9718 [#:properties '()] [#:guile-for-build #f]
9719 Return a derivation @var{name} that runs @var{exp} (a gexp) with
9720 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
9721 stored in a file called @var{script-name}. When @var{target} is true,
9722 it is used as the cross-compilation target triplet for packages referred
9725 @var{modules} is deprecated in favor of @code{with-imported-modules}.
9727 make @var{modules} available in the evaluation context of @var{exp};
9728 @var{modules} is a list of names of Guile modules searched in
9729 @var{module-path} to be copied in the store, compiled, and made available in
9730 the load path during the execution of @var{exp}---e.g., @code{((guix
9731 build utils) (guix build gnu-build-system))}.
9733 @var{effective-version} determines the string to use when adding extensions of
9734 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
9736 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
9739 When @var{references-graphs} is true, it must be a list of tuples of one of the
9743 (@var{file-name} @var{package})
9744 (@var{file-name} @var{package} @var{output})
9745 (@var{file-name} @var{derivation})
9746 (@var{file-name} @var{derivation} @var{output})
9747 (@var{file-name} @var{store-item})
9750 The right-hand-side of each element of @var{references-graphs} is automatically made
9751 an input of the build process of @var{exp}. In the build environment, each
9752 @var{file-name} contains the reference graph of the corresponding item, in a simple
9755 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
9756 In the latter case, the list denotes store items that the result is allowed to
9757 refer to. Any reference to another store item will lead to a build error.
9758 Similarly for @var{disallowed-references}, which can list items that must not be
9759 referenced by the outputs.
9761 @var{deprecation-warnings} determines whether to show deprecation warnings while
9762 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
9764 The other arguments are as for @code{derivation} (@pxref{Derivations}).
9767 @cindex file-like objects
9768 The @code{local-file}, @code{plain-file}, @code{computed-file},
9769 @code{program-file}, and @code{scheme-file} procedures below return
9770 @dfn{file-like objects}. That is, when unquoted in a G-expression,
9771 these objects lead to a file in the store. Consider this G-expression:
9774 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
9775 #$(local-file "/tmp/my-nscd.conf"))
9778 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
9779 to the store. Once expanded, for instance @i{via}
9780 @code{gexp->derivation}, the G-expression refers to that copy under
9781 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
9782 does not have any effect on what the G-expression does.
9783 @code{plain-file} can be used similarly; it differs in that the file
9784 content is directly passed as a string.
9786 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
9787 [#:recursive? #f] [#:select? (const #t)]
9788 Return an object representing local file @var{file} to add to the store;
9789 this object can be used in a gexp. If @var{file} is a literal string
9790 denoting a relative file name, it is looked up relative to the source
9791 file where it appears; if @var{file} is not a literal string, it is
9792 looked up relative to the current working directory at run time.
9793 @var{file} will be added to the store under @var{name}--by default the
9794 base name of @var{file}.
9796 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
9797 designates a flat file and @var{recursive?} is true, its contents are added, and its
9798 permission bits are kept.
9800 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
9801 @var{stat})} for each directory entry, where @var{file} is the entry's
9802 absolute file name and @var{stat} is the result of @code{lstat}; exclude
9803 entries for which @var{select?} does not return true.
9805 This is the declarative counterpart of the @code{interned-file} monadic
9806 procedure (@pxref{The Store Monad, @code{interned-file}}).
9809 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
9810 Return an object representing a text file called @var{name} with the given
9811 @var{content} (a string or a bytevector) to be added to the store.
9813 This is the declarative counterpart of @code{text-file}.
9816 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
9819 Return an object representing the store item @var{name}, a file or
9820 directory computed by @var{gexp}. When @var{local-build?} is true (the
9821 default), the derivation is built locally. @var{options} is a list of
9822 additional arguments to pass to @code{gexp->derivation}.
9824 This is the declarative counterpart of @code{gexp->derivation}.
9827 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
9828 [#:guile (default-guile)] [#:module-path %load-path] @
9829 [#:system (%current-system)] [#:target #f]
9830 Return an executable script @var{name} that runs @var{exp} using
9831 @var{guile}, with @var{exp}'s imported modules in its search path.
9832 Look up @var{exp}'s modules in @var{module-path}.
9834 The example below builds a script that simply invokes the @command{ls}
9838 (use-modules (guix gexp) (gnu packages base))
9840 (gexp->script "list-files"
9841 #~(execl #$(file-append coreutils "/bin/ls")
9845 When ``running'' it through the store (@pxref{The Store Monad,
9846 @code{run-with-store}}), we obtain a derivation that produces an
9847 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
9850 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
9852 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
9856 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
9857 [#:guile #f] [#:module-path %load-path]
9858 Return an object representing the executable store item @var{name} that
9859 runs @var{gexp}. @var{guile} is the Guile package used to execute that
9860 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
9862 This is the declarative counterpart of @code{gexp->script}.
9865 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
9866 [#:set-load-path? #t] [#:module-path %load-path] @
9868 [#:guile (default-guile)]
9869 Return a derivation that builds a file @var{name} containing @var{exp}.
9870 When @var{splice?} is true, @var{exp} is considered to be a list of
9871 expressions that will be spliced in the resulting file.
9873 When @var{set-load-path?} is true, emit code in the resulting file to
9874 set @code{%load-path} and @code{%load-compiled-path} to honor
9875 @var{exp}'s imported modules. Look up @var{exp}'s modules in
9878 The resulting file holds references to all the dependencies of @var{exp}
9879 or a subset thereof.
9882 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} @
9883 [#:splice? #f] [#:set-load-path? #t]
9884 Return an object representing the Scheme file @var{name} that contains
9887 This is the declarative counterpart of @code{gexp->file}.
9890 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
9891 Return as a monadic value a derivation that builds a text file
9892 containing all of @var{text}. @var{text} may list, in addition to
9893 strings, objects of any type that can be used in a gexp: packages,
9894 derivations, local file objects, etc. The resulting store file holds
9895 references to all these.
9897 This variant should be preferred over @code{text-file} anytime the file
9898 to create will reference items from the store. This is typically the
9899 case when building a configuration file that embeds store file names,
9903 (define (profile.sh)
9904 ;; Return the name of a shell script in the store that
9905 ;; initializes the 'PATH' environment variable.
9906 (text-file* "profile.sh"
9907 "export PATH=" coreutils "/bin:"
9908 grep "/bin:" sed "/bin\n"))
9911 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
9912 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
9913 preventing them from being garbage-collected during its lifetime.
9916 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
9917 Return an object representing store file @var{name} containing
9918 @var{text}. @var{text} is a sequence of strings and file-like objects,
9922 (mixed-text-file "profile"
9923 "export PATH=" coreutils "/bin:" grep "/bin")
9926 This is the declarative counterpart of @code{text-file*}.
9929 @deffn {Scheme Procedure} file-union @var{name} @var{files}
9930 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
9931 Each item in @var{files} must be a two-element list where the first element is the
9932 file name to use in the new directory, and the second element is a gexp
9933 denoting the target file. Here's an example:
9937 `(("hosts" ,(plain-file "hosts"
9938 "127.0.0.1 localhost"))
9939 ("bashrc" ,(plain-file "bashrc"
9940 "alias ls='ls --color=auto'"))))
9943 This yields an @code{etc} directory containing these two files.
9946 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
9947 Return a directory that is the union of @var{things}, where @var{things} is a list of
9948 file-like objects denoting directories. For example:
9951 (directory-union "guile+emacs" (list guile emacs))
9954 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
9957 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
9958 Return a file-like object that expands to the concatenation of @var{obj}
9959 and @var{suffix}, where @var{obj} is a lowerable object and each
9960 @var{suffix} is a string.
9962 As an example, consider this gexp:
9965 (gexp->script "run-uname"
9966 #~(system* #$(file-append coreutils
9970 The same effect could be achieved with:
9973 (gexp->script "run-uname"
9974 #~(system* (string-append #$coreutils
9978 There is one difference though: in the @code{file-append} case, the
9979 resulting script contains the absolute file name as a string, whereas in
9980 the second case, the resulting script contains a @code{(string-append
9981 @dots{})} expression to construct the file name @emph{at run time}.
9984 @deffn {Scheme Syntax} let-system @var{system} @var{body}@dots{}
9985 @deffnx {Scheme Syntax} let-system (@var{system} @var{target}) @var{body}@dots{}
9986 Bind @var{system} to the currently targeted system---e.g.,
9987 @code{"x86_64-linux"}---within @var{body}.
9989 In the second case, additionally bind @var{target} to the current
9990 cross-compilation target---a GNU triplet such as
9991 @code{"arm-linux-gnueabihf"}---or @code{#f} if we are not
9994 @code{let-system} is useful in the occasional case where the object
9995 spliced into the gexp depends on the target system, as in this example:
9999 #+(let-system system
10000 (cond ((string-prefix? "armhf-" system)
10001 (file-append qemu "/bin/qemu-system-arm"))
10002 ((string-prefix? "x86_64-" system)
10003 (file-append qemu "/bin/qemu-system-x86_64"))
10005 (error "dunno!"))))
10006 "-net" "user" #$image)
10010 @deffn {Scheme Syntax} with-parameters ((@var{parameter} @var{value}) @dots{}) @var{exp}
10011 This macro is similar to the @code{parameterize} form for
10012 dynamically-bound @dfn{parameters} (@pxref{Parameters,,, guile, GNU
10013 Guile Reference Manual}). The key difference is that it takes effect
10014 when the file-like object returned by @var{exp} is lowered to a
10015 derivation or store item.
10017 A typical use of @code{with-parameters} is to force the system in effect
10018 for a given object:
10021 (with-parameters ((%current-system "i686-linux"))
10025 The example above returns an object that corresponds to the i686 build
10026 of Coreutils, regardless of the current value of @code{%current-system}.
10030 Of course, in addition to gexps embedded in ``host'' code, there are
10031 also modules containing build tools. To make it clear that they are
10032 meant to be used in the build stratum, these modules are kept in the
10033 @code{(guix build @dots{})} name space.
10035 @cindex lowering, of high-level objects in gexps
10036 Internally, high-level objects are @dfn{lowered}, using their compiler,
10037 to either derivations or store items. For instance, lowering a package
10038 yields a derivation, and lowering a @code{plain-file} yields a store
10039 item. This is achieved using the @code{lower-object} monadic procedure.
10041 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
10043 Return as a value in @code{%store-monad} the derivation or store item
10044 corresponding to @var{obj} for @var{system}, cross-compiling for
10045 @var{target} if @var{target} is true. @var{obj} must be an object that
10046 has an associated gexp compiler, such as a @code{<package>}.
10049 @node Invoking guix repl
10050 @section Invoking @command{guix repl}
10052 @cindex REPL, read-eval-print loop, script
10053 The @command{guix repl} command makes it easier to program Guix in Guile
10054 by launching a Guile @dfn{read-eval-print loop} (REPL) for interactive
10055 programming (@pxref{Using Guile Interactively,,, guile,
10056 GNU Guile Reference Manual}), or by running Guile scripts
10057 (@pxref{Running Guile Scripts,,, guile,
10058 GNU Guile Reference Manual}).
10059 Compared to just launching the @command{guile}
10060 command, @command{guix repl} guarantees that all the Guix modules and all its
10061 dependencies are available in the search path.
10063 The general syntax is:
10066 guix repl @var{options} [@var{file} @var{args}]
10069 When a @var{file} argument is provided, @var{file} is
10070 executed as a Guile scripts:
10073 guix repl my-script.scm
10076 To pass arguments to the script, use @code{--} to prevent them from
10077 being interpreted as arguments to @command{guix repl} itself:
10080 guix repl -- my-script.scm --input=foo.txt
10083 To make a script executable directly from the shell, using the guix
10084 executable that is on the user's search path, add the following two
10085 lines at the top of the script:
10088 @code{#!/usr/bin/env -S guix repl --}
10092 Without a file name argument, a Guile REPL is started:
10096 scheme@@(guile-user)> ,use (gnu packages base)
10097 scheme@@(guile-user)> coreutils
10098 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
10102 In addition, @command{guix repl} implements a simple machine-readable REPL
10103 protocol for use by @code{(guix inferior)}, a facility to interact with
10104 @dfn{inferiors}, separate processes running a potentially different revision
10107 The available options are as follows:
10110 @item --type=@var{type}
10111 @itemx -t @var{type}
10112 Start a REPL of the given @var{TYPE}, which can be one of the following:
10116 This is default, and it spawns a standard full-featured Guile REPL.
10118 Spawn a REPL that uses the machine-readable protocol. This is the protocol
10119 that the @code{(guix inferior)} module speaks.
10122 @item --listen=@var{endpoint}
10123 By default, @command{guix repl} reads from standard input and writes to
10124 standard output. When this option is passed, it will instead listen for
10125 connections on @var{endpoint}. Here are examples of valid options:
10128 @item --listen=tcp:37146
10129 Accept connections on localhost on port 37146.
10131 @item --listen=unix:/tmp/socket
10132 Accept connections on the Unix-domain socket @file{/tmp/socket}.
10135 @item --load-path=@var{directory}
10136 @itemx -L @var{directory}
10137 Add @var{directory} to the front of the package module search path
10138 (@pxref{Package Modules}).
10140 This allows users to define their own packages and make them visible to
10141 the script or REPL.
10144 Inhibit loading of the @file{~/.guile} file. By default, that
10145 configuration file is loaded when spawning a @code{guile} REPL.
10148 @c *********************************************************************
10152 This section describes Guix command-line utilities. Some of them are
10153 primarily targeted at developers and users who write new package
10154 definitions, while others are more generally useful. They complement
10155 the Scheme programming interface of Guix in a convenient way.
10158 * Invoking guix build:: Building packages from the command line.
10159 * Invoking guix edit:: Editing package definitions.
10160 * Invoking guix download:: Downloading a file and printing its hash.
10161 * Invoking guix hash:: Computing the cryptographic hash of a file.
10162 * Invoking guix import:: Importing package definitions.
10163 * Invoking guix refresh:: Updating package definitions.
10164 * Invoking guix lint:: Finding errors in package definitions.
10165 * Invoking guix size:: Profiling disk usage.
10166 * Invoking guix graph:: Visualizing the graph of packages.
10167 * Invoking guix publish:: Sharing substitutes.
10168 * Invoking guix challenge:: Challenging substitute servers.
10169 * Invoking guix copy:: Copying to and from a remote store.
10170 * Invoking guix container:: Process isolation.
10171 * Invoking guix weather:: Assessing substitute availability.
10172 * Invoking guix processes:: Listing client processes.
10175 @node Invoking guix build
10176 @section Invoking @command{guix build}
10178 @cindex package building
10179 @cindex @command{guix build}
10180 The @command{guix build} command builds packages or derivations and
10181 their dependencies, and prints the resulting store paths. Note that it
10182 does not modify the user's profile---this is the job of the
10183 @command{guix package} command (@pxref{Invoking guix package}). Thus,
10184 it is mainly useful for distribution developers.
10186 The general syntax is:
10189 guix build @var{options} @var{package-or-derivation}@dots{}
10192 As an example, the following command builds the latest versions of Emacs
10193 and of Guile, displays their build logs, and finally displays the
10194 resulting directories:
10197 guix build emacs guile
10200 Similarly, the following command builds all the available packages:
10203 guix build --quiet --keep-going \
10204 $(guix package -A | cut -f1,2 --output-delimiter=@@)
10207 @var{package-or-derivation} may be either the name of a package found in
10208 the software distribution such as @code{coreutils} or
10209 @code{coreutils@@8.20}, or a derivation such as
10210 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
10211 package with the corresponding name (and optionally version) is searched
10212 for among the GNU distribution modules (@pxref{Package Modules}).
10214 Alternatively, the @option{--expression} option may be used to specify a
10215 Scheme expression that evaluates to a package; this is useful when
10216 disambiguating among several same-named packages or package variants is
10219 There may be zero or more @var{options}. The available options are
10220 described in the subsections below.
10223 * Common Build Options:: Build options for most commands.
10224 * Package Transformation Options:: Creating variants of packages.
10225 * Additional Build Options:: Options specific to 'guix build'.
10226 * Debugging Build Failures:: Real life packaging experience.
10229 @node Common Build Options
10230 @subsection Common Build Options
10232 A number of options that control the build process are common to
10233 @command{guix build} and other commands that can spawn builds, such as
10234 @command{guix package} or @command{guix archive}. These are the
10239 @item --load-path=@var{directory}
10240 @itemx -L @var{directory}
10241 Add @var{directory} to the front of the package module search path
10242 (@pxref{Package Modules}).
10244 This allows users to define their own packages and make them visible to
10245 the command-line tools.
10247 @item --keep-failed
10249 Keep the build tree of failed builds. Thus, if a build fails, its build
10250 tree is kept under @file{/tmp}, in a directory whose name is shown at
10251 the end of the build log. This is useful when debugging build issues.
10252 @xref{Debugging Build Failures}, for tips and tricks on how to debug
10255 This option implies @option{--no-offload}, and it has no effect when
10256 connecting to a remote daemon with a @code{guix://} URI (@pxref{The
10257 Store, the @env{GUIX_DAEMON_SOCKET} variable}).
10261 Keep going when some of the derivations fail to build; return only once
10262 all the builds have either completed or failed.
10264 The default behavior is to stop as soon as one of the specified
10265 derivations has failed.
10269 Do not build the derivations.
10271 @anchor{fallback-option}
10273 When substituting a pre-built binary fails, fall back to building
10274 packages locally (@pxref{Substitution Failure}).
10276 @item --substitute-urls=@var{urls}
10277 @anchor{client-substitute-urls}
10278 Consider @var{urls} the whitespace-separated list of substitute source
10279 URLs, overriding the default list of URLs of @command{guix-daemon}
10280 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
10282 This means that substitutes may be downloaded from @var{urls}, provided
10283 they are signed by a key authorized by the system administrator
10284 (@pxref{Substitutes}).
10286 When @var{urls} is the empty string, substitutes are effectively
10289 @item --no-substitutes
10290 Do not use substitutes for build products. That is, always build things
10291 locally instead of allowing downloads of pre-built binaries
10292 (@pxref{Substitutes}).
10295 Do not ``graft'' packages. In practice, this means that package updates
10296 available as grafts are not applied. @xref{Security Updates}, for more
10297 information on grafts.
10299 @item --rounds=@var{n}
10300 Build each derivation @var{n} times in a row, and raise an error if
10301 consecutive build results are not bit-for-bit identical.
10303 This is a useful way to detect non-deterministic builds processes.
10304 Non-deterministic build processes are a problem because they make it
10305 practically impossible for users to @emph{verify} whether third-party
10306 binaries are genuine. @xref{Invoking guix challenge}, for more.
10308 When used in conjunction with @option{--keep-failed}, the differing
10309 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
10310 This makes it easy to look for differences between the two results.
10313 Do not use offload builds to other machines (@pxref{Daemon Offload
10314 Setup}). That is, always build things locally instead of offloading
10315 builds to remote machines.
10317 @item --max-silent-time=@var{seconds}
10318 When the build or substitution process remains silent for more than
10319 @var{seconds}, terminate it and report a build failure.
10321 By default, the daemon's setting is honored (@pxref{Invoking
10322 guix-daemon, @option{--max-silent-time}}).
10324 @item --timeout=@var{seconds}
10325 Likewise, when the build or substitution process lasts for more than
10326 @var{seconds}, terminate it and report a build failure.
10328 By default, the daemon's setting is honored (@pxref{Invoking
10329 guix-daemon, @option{--timeout}}).
10331 @c Note: This option is actually not part of %standard-build-options but
10332 @c most programs honor it.
10333 @cindex verbosity, of the command-line tools
10334 @cindex build logs, verbosity
10335 @item -v @var{level}
10336 @itemx --verbosity=@var{level}
10337 Use the given verbosity @var{level}, an integer. Choosing 0 means that
10338 no output is produced, 1 is for quiet output; 2 is similar to 1 but it
10339 additionally displays download URLs; 3 shows all the build log output on
10342 @item --cores=@var{n}
10344 Allow the use of up to @var{n} CPU cores for the build. The special
10345 value @code{0} means to use as many CPU cores as available.
10347 @item --max-jobs=@var{n}
10349 Allow at most @var{n} build jobs in parallel. @xref{Invoking
10350 guix-daemon, @option{--max-jobs}}, for details about this option and the
10351 equivalent @command{guix-daemon} option.
10353 @item --debug=@var{level}
10354 Produce debugging output coming from the build daemon. @var{level} must be an
10355 integer between 0 and 5; higher means more verbose output. Setting a level of
10356 4 or more may be helpful when debugging setup issues with the build daemon.
10360 Behind the scenes, @command{guix build} is essentially an interface to
10361 the @code{package-derivation} procedure of the @code{(guix packages)}
10362 module, and to the @code{build-derivations} procedure of the @code{(guix
10363 derivations)} module.
10365 In addition to options explicitly passed on the command line,
10366 @command{guix build} and other @command{guix} commands that support
10367 building honor the @env{GUIX_BUILD_OPTIONS} environment variable.
10369 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
10370 Users can define this variable to a list of command line options that
10371 will automatically be used by @command{guix build} and other
10372 @command{guix} commands that can perform builds, as in the example
10376 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
10379 These options are parsed independently, and the result is appended to
10380 the parsed command-line options.
10384 @node Package Transformation Options
10385 @subsection Package Transformation Options
10387 @cindex package variants
10388 Another set of command-line options supported by @command{guix build}
10389 and also @command{guix package} are @dfn{package transformation
10390 options}. These are options that make it possible to define @dfn{package
10391 variants}---for instance, packages built from different source code.
10392 This is a convenient way to create customized packages on the fly
10393 without having to type in the definitions of package variants
10394 (@pxref{Defining Packages}).
10396 Package transformation options are preserved across upgrades:
10397 @command{guix upgrade} attempts to apply transformation options
10398 initially used when creating the profile to the upgraded packages.
10400 The available options are listed below. Most commands support them and
10401 also support a @option{--help-transform} option that lists all the
10402 available options and a synopsis (these options are not shown in the
10403 @option{--help} output for brevity).
10407 @item --with-source=@var{source}
10408 @itemx --with-source=@var{package}=@var{source}
10409 @itemx --with-source=@var{package}@@@var{version}=@var{source}
10410 Use @var{source} as the source of @var{package}, and @var{version} as
10411 its version number.
10412 @var{source} must be a file name or a URL, as for @command{guix
10413 download} (@pxref{Invoking guix download}).
10415 When @var{package} is omitted,
10416 it is taken to be the package name specified on the
10417 command line that matches the base of @var{source}---e.g.,
10418 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
10419 package is @code{guile}.
10421 Likewise, when @var{version} is omitted, the version string is inferred from
10422 @var{source}; in the previous example, it is @code{2.0.10}.
10424 This option allows users to try out versions of packages other than the
10425 one provided by the distribution. The example below downloads
10426 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
10427 the @code{ed} package:
10430 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
10433 As a developer, @option{--with-source} makes it easy to test release
10437 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
10440 @dots{} or to build from a checkout in a pristine environment:
10443 $ git clone git://git.sv.gnu.org/guix.git
10444 $ guix build guix --with-source=guix@@1.0=./guix
10447 @item --with-input=@var{package}=@var{replacement}
10448 Replace dependency on @var{package} by a dependency on
10449 @var{replacement}. @var{package} must be a package name, and
10450 @var{replacement} must be a package specification such as @code{guile}
10451 or @code{guile@@1.8}.
10453 For instance, the following command builds Guix, but replaces its
10454 dependency on the current stable version of Guile with a dependency on
10455 the legacy version of Guile, @code{guile@@2.0}:
10458 guix build --with-input=guile=guile@@2.0 guix
10461 This is a recursive, deep replacement. So in this example, both
10462 @code{guix} and its dependency @code{guile-json} (which also depends on
10463 @code{guile}) get rebuilt against @code{guile@@2.0}.
10465 This is implemented using the @code{package-input-rewriting} Scheme
10466 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
10468 @item --with-graft=@var{package}=@var{replacement}
10469 This is similar to @option{--with-input} but with an important difference:
10470 instead of rebuilding the whole dependency chain, @var{replacement} is
10471 built and then @dfn{grafted} onto the binaries that were initially
10472 referring to @var{package}. @xref{Security Updates}, for more
10473 information on grafts.
10475 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
10476 and all its dependencies, replacing references to the version of GnuTLS
10477 they currently refer to:
10480 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
10483 This has the advantage of being much faster than rebuilding everything.
10484 But there is a caveat: it works if and only if @var{package} and
10485 @var{replacement} are strictly compatible---for example, if they provide
10486 a library, the application binary interface (ABI) of those libraries
10487 must be compatible. If @var{replacement} is somehow incompatible with
10488 @var{package}, then the resulting package may be unusable. Use with
10491 @cindex debugging info, rebuilding
10492 @item --with-debug-info=@var{package}
10493 Build @var{package} in a way that preserves its debugging info and graft
10494 it onto packages that depend on it. This is useful if @var{package}
10495 does not already provide debugging info as a @code{debug} output
10496 (@pxref{Installing Debugging Files}).
10498 For example, suppose you're experiencing a crash in Inkscape and would
10499 like to see what's up in GLib, a library deep down in Inkscape's
10500 dependency graph. GLib lacks a @code{debug} output, so debugging is
10501 tough. Fortunately, you rebuild GLib with debugging info and tack it on
10505 guix install inkscape --with-debug-info=glib
10508 Only GLib needs to be recompiled so this takes a reasonable amount of
10509 time. @xref{Installing Debugging Files}, for more info.
10512 Under the hood, this option works by passing the @samp{#:strip-binaries?
10513 #f} to the build system of the package of interest (@pxref{Build
10514 Systems}). Most build systems support that option but some do not. In
10515 that case, an error is raised.
10517 Likewise, if a C/C++ package is built without @code{-g} (which is rarely
10518 the case), debugging info will remain unavailable even when
10519 @code{#:strip-binaries?} is false.
10522 @cindex tool chain, changing the build tool chain of a package
10523 @item --with-c-toolchain=@var{package}=@var{toolchain}
10524 This option changes the compilation of @var{package} and everything that
10525 depends on it so that they get built with @var{toolchain} instead of the
10526 default GNU tool chain for C/C++.
10528 Consider this example:
10531 guix build octave-cli \
10532 --with-c-toolchain=fftw=gcc-toolchain@@10 \
10533 --with-c-toolchain=fftwf=gcc-toolchain@@10
10536 The command above builds a variant of the @code{fftw} and @code{fftwf}
10537 packages using version 10 of @code{gcc-toolchain} instead of the default
10538 tool chain, and then builds a variant of the GNU@tie{}Octave
10539 command-line interface using them. GNU@tie{}Octave itself is also built
10540 with @code{gcc-toolchain@@10}.
10542 This other example builds the Hardware Locality (@code{hwloc}) library
10543 and its dependents up to @code{intel-mpi-benchmarks} with the Clang C
10547 guix build --with-c-toolchain=hwloc=clang-toolchain \
10548 intel-mpi-benchmarks
10552 There can be application binary interface (ABI) incompatibilities among
10553 tool chains. This is particularly true of the C++ standard library and
10554 run-time support libraries such as that of OpenMP@. By rebuilding all
10555 dependents with the same tool chain, @option{--with-c-toolchain} minimizes
10556 the risks of incompatibility but cannot entirely eliminate them. Choose
10557 @var{package} wisely.
10560 @item --with-git-url=@var{package}=@var{url}
10561 @cindex Git, using the latest commit
10562 @cindex latest commit, building
10563 Build @var{package} from the latest commit of the @code{master} branch of the
10564 Git repository at @var{url}. Git sub-modules of the repository are fetched,
10567 For example, the following command builds the NumPy Python library against the
10568 latest commit of the master branch of Python itself:
10571 guix build python-numpy \
10572 --with-git-url=python=https://github.com/python/cpython
10575 This option can also be combined with @option{--with-branch} or
10576 @option{--with-commit} (see below).
10578 @cindex continuous integration
10579 Obviously, since it uses the latest commit of the given branch, the result of
10580 such a command varies over time. Nevertheless it is a convenient way to
10581 rebuild entire software stacks against the latest commit of one or more
10582 packages. This is particularly useful in the context of continuous
10585 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
10586 consecutive accesses to the same repository. You may want to clean it up once
10587 in a while to save disk space.
10589 @item --with-branch=@var{package}=@var{branch}
10590 Build @var{package} from the latest commit of @var{branch}. If the
10591 @code{source} field of @var{package} is an origin with the @code{git-fetch}
10592 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
10593 repository URL is taken from that @code{source}. Otherwise you have to use
10594 @option{--with-git-url} to specify the URL of the Git repository.
10596 For instance, the following command builds @code{guile-sqlite3} from the
10597 latest commit of its @code{master} branch, and then builds @code{guix} (which
10598 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
10599 specific @code{guile-sqlite3} build:
10602 guix build --with-branch=guile-sqlite3=master cuirass
10605 @item --with-commit=@var{package}=@var{commit}
10606 This is similar to @option{--with-branch}, except that it builds from
10607 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
10608 Git commit SHA1 identifier or a tag.
10610 @item --with-patch=@var{package}=@var{file}
10611 Add @var{file} to the list of patches applied to @var{package}, where
10612 @var{package} is a spec such as @code{python@@3.8} or @code{glibc}.
10613 @var{file} must contain a patch; it is applied with the flags specified
10614 in the @code{origin} of @var{package} (@pxref{origin Reference}), which
10615 by default includes @code{-p1} (@pxref{patch Directories,,, diffutils,
10616 Comparing and Merging Files}).
10618 As an example, the command below rebuilds Coreutils with the GNU C
10619 Library (glibc) patched with the given patch:
10622 guix build coreutils --with-patch=glibc=./glibc-frob.patch
10625 In this example, glibc itself as well as everything that leads to
10626 Coreutils in the dependency graph is rebuilt.
10628 @cindex upstream, latest version
10629 @item --with-latest=@var{package}
10630 So you like living on the bleeding edge? This option is for you! It
10631 replaces occurrences of @var{package} in the dependency graph with its
10632 latest upstream version, as reported by @command{guix refresh}
10633 (@pxref{Invoking guix refresh}).
10635 It does so by determining the latest upstream release of @var{package}
10636 (if possible), downloading it, and authenticating it @emph{if} it comes
10637 with an OpenPGP signature.
10639 As an example, the command below builds Guix against the latest version
10643 guix build guix --with-latest=guile-json
10646 There are limitations. First, in cases where the tool cannot or does
10647 not know how to authenticate source code, you are at risk of running
10648 malicious code; a warning is emitted in this case. Second, this option
10649 simply changes the source used in the existing package definitions,
10650 which is not always sufficient: there might be additional dependencies
10651 that need to be added, patches to apply, and more generally the quality
10652 assurance work that Guix developers normally do will be missing.
10654 You've been warned! In all the other cases, it's a snappy way to stay
10655 on top. We encourage you to submit patches updating the actual package
10656 definitions once you have successfully tested an upgrade
10657 (@pxref{Contributing}).
10659 @cindex test suite, skipping
10660 @item --without-tests=@var{package}
10661 Build @var{package} without running its tests. This can be useful in
10662 situations where you want to skip the lengthy test suite of a
10663 intermediate package, or if a package's test suite fails in a
10664 non-deterministic fashion. It should be used with care because running
10665 the test suite is a good way to ensure a package is working as intended.
10667 Turning off tests leads to a different store item. Consequently, when
10668 using this option, anything that depends on @var{package} must be
10669 rebuilt, as in this example:
10672 guix install --without-tests=python python-notebook
10675 The command above installs @code{python-notebook} on top of
10676 @code{python} built without running its test suite. To do so, it also
10677 rebuilds everything that depends on @code{python}, including
10678 @code{python-notebook} itself.
10680 Internally, @option{--without-tests} relies on changing the
10681 @code{#:tests?} option of a package's @code{check} phase (@pxref{Build
10682 Systems}). Note that some packages use a customized @code{check} phase
10683 that does not respect a @code{#:tests? #f} setting. Therefore,
10684 @option{--without-tests} has no effect on these packages.
10688 Wondering how to achieve the same effect using Scheme code, for example
10689 in your manifest, or how to write your own package transformation?
10690 @xref{Defining Package Variants}, for an overview of the programming
10691 interfaces available.
10693 @node Additional Build Options
10694 @subsection Additional Build Options
10696 The command-line options presented below are specific to @command{guix
10703 Build quietly, without displaying the build log; this is equivalent to
10704 @option{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
10705 (or similar) and can always be retrieved using the @option{--log-file} option.
10707 @item --file=@var{file}
10708 @itemx -f @var{file}
10709 Build the package, derivation, or other file-like object that the code within
10710 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
10712 As an example, @var{file} might contain a package definition like this
10713 (@pxref{Defining Packages}):
10716 @include package-hello.scm
10719 The @var{file} may also contain a JSON representation of one or more
10720 package definitions. Running @code{guix build -f} on @file{hello.json}
10721 with the following contents would result in building the packages
10722 @code{myhello} and @code{greeter}:
10725 @verbatiminclude package-hello.json
10728 @item --manifest=@var{manifest}
10729 @itemx -m @var{manifest}
10730 Build all packages listed in the given @var{manifest}
10731 (@pxref{profile-manifest, @option{--manifest}}).
10733 @item --expression=@var{expr}
10734 @itemx -e @var{expr}
10735 Build the package or derivation @var{expr} evaluates to.
10737 For example, @var{expr} may be @code{(@@ (gnu packages guile)
10738 guile-1.8)}, which unambiguously designates this specific variant of
10739 version 1.8 of Guile.
10741 Alternatively, @var{expr} may be a G-expression, in which case it is used
10742 as a build program passed to @code{gexp->derivation}
10743 (@pxref{G-Expressions}).
10745 Lastly, @var{expr} may refer to a zero-argument monadic procedure
10746 (@pxref{The Store Monad}). The procedure must return a derivation as a
10747 monadic value, which is then passed through @code{run-with-store}.
10751 Build the source derivations of the packages, rather than the packages
10754 For instance, @code{guix build -S gcc} returns something like
10755 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
10758 The returned source tarball is the result of applying any patches and
10759 code snippets specified in the package @code{origin} (@pxref{Defining
10762 @cindex source, verification
10763 As with other derivations, the result of building a source derivation
10764 can be verified using the @option{--check} option (@pxref{build-check}).
10765 This is useful to validate that a (potentially already built or
10766 substituted, thus cached) package source matches against its declared
10769 Note that @command{guix build -S} compiles the sources only of the
10770 specified packages. They do not include the sources of statically
10771 linked dependencies and by themselves are insufficient for reproducing
10775 Fetch and return the source of @var{package-or-derivation} and all their
10776 dependencies, recursively. This is a handy way to obtain a local copy
10777 of all the source code needed to build @var{packages}, allowing you to
10778 eventually build them even without network access. It is an extension
10779 of the @option{--source} option and can accept one of the following
10780 optional argument values:
10784 This value causes the @option{--sources} option to behave in the same way
10785 as the @option{--source} option.
10788 Build the source derivations of all packages, including any source that
10789 might be listed as @code{inputs}. This is the default value.
10792 $ guix build --sources tzdata
10793 The following derivations will be built:
10794 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
10795 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
10799 Build the source derivations of all packages, as well of all transitive
10800 inputs to the packages. This can be used e.g.@: to
10801 prefetch package source for later offline building.
10804 $ guix build --sources=transitive tzdata
10805 The following derivations will be built:
10806 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
10807 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
10808 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
10809 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
10810 /gnu/store/@dots{}-make-4.1.tar.xz.drv
10811 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
10817 @item --system=@var{system}
10818 @itemx -s @var{system}
10819 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
10820 the system type of the build host. The @command{guix build} command allows
10821 you to repeat this option several times, in which case it builds for all the
10822 specified systems; other commands ignore extraneous @option{-s} options.
10825 The @option{--system} flag is for @emph{native} compilation and must not
10826 be confused with cross-compilation. See @option{--target} below for
10827 information on cross-compilation.
10830 An example use of this is on Linux-based systems, which can emulate
10831 different personalities. For instance, passing
10832 @option{--system=i686-linux} on an @code{x86_64-linux} system or
10833 @option{--system=armhf-linux} on an @code{aarch64-linux} system allows
10834 you to build packages in a complete 32-bit environment.
10837 Building for an @code{armhf-linux} system is unconditionally enabled on
10838 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
10839 allow for this functionality, notably the ThunderX.
10842 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
10843 is enabled (@pxref{Virtualization Services,
10844 @code{qemu-binfmt-service-type}}), you can build for any system for
10845 which a QEMU @code{binfmt_misc} handler is installed.
10847 Builds for a system other than that of the machine you are using can
10848 also be offloaded to a remote machine of the right architecture.
10849 @xref{Daemon Offload Setup}, for more information on offloading.
10851 @item --target=@var{triplet}
10852 @cindex cross-compilation
10853 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
10854 as @code{"aarch64-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
10855 configuration triplets,, autoconf, Autoconf}).
10857 @anchor{build-check}
10859 @cindex determinism, checking
10860 @cindex reproducibility, checking
10861 Rebuild @var{package-or-derivation}, which are already available in the
10862 store, and raise an error if the build results are not bit-for-bit
10865 This mechanism allows you to check whether previously installed
10866 substitutes are genuine (@pxref{Substitutes}), or whether the build result
10867 of a package is deterministic. @xref{Invoking guix challenge}, for more
10868 background information and tools.
10870 When used in conjunction with @option{--keep-failed}, the differing
10871 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
10872 This makes it easy to look for differences between the two results.
10875 @cindex repairing store items
10876 @cindex corruption, recovering from
10877 Attempt to repair the specified store items, if they are corrupt, by
10878 re-downloading or rebuilding them.
10880 This operation is not atomic and thus restricted to @code{root}.
10882 @item --derivations
10884 Return the derivation paths, not the output paths, of the given
10887 @item --root=@var{file}
10888 @itemx -r @var{file}
10889 @cindex GC roots, adding
10890 @cindex garbage collector roots, adding
10891 Make @var{file} a symlink to the result, and register it as a garbage
10894 Consequently, the results of this @command{guix build} invocation are
10895 protected from garbage collection until @var{file} is removed. When
10896 that option is omitted, build results are eligible for garbage
10897 collection as soon as the build completes. @xref{Invoking guix gc}, for
10901 @cindex build logs, access
10902 Return the build log file names or URLs for the given
10903 @var{package-or-derivation}, or raise an error if build logs are
10906 This works regardless of how packages or derivations are specified. For
10907 instance, the following invocations are equivalent:
10910 guix build --log-file $(guix build -d guile)
10911 guix build --log-file $(guix build guile)
10912 guix build --log-file guile
10913 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
10916 If a log is unavailable locally, and unless @option{--no-substitutes} is
10917 passed, the command looks for a corresponding log on one of the
10918 substitute servers (as specified with @option{--substitute-urls}).
10920 So for instance, imagine you want to see the build log of GDB on MIPS,
10921 but you are actually on an @code{x86_64} machine:
10924 $ guix build --log-file gdb -s aarch64-linux
10925 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
10928 You can freely access a huge library of build logs!
10931 @node Debugging Build Failures
10932 @subsection Debugging Build Failures
10934 @cindex build failures, debugging
10935 When defining a new package (@pxref{Defining Packages}), you will
10936 probably find yourself spending some time debugging and tweaking the
10937 build until it succeeds. To do that, you need to operate the build
10938 commands yourself in an environment as close as possible to the one the
10941 To that end, the first thing to do is to use the @option{--keep-failed}
10942 or @option{-K} option of @command{guix build}, which will keep the
10943 failed build tree in @file{/tmp} or whatever directory you specified as
10944 @env{TMPDIR} (@pxref{Common Build Options, @option{--keep-failed}}).
10946 From there on, you can @command{cd} to the failed build tree and source
10947 the @file{environment-variables} file, which contains all the
10948 environment variable definitions that were in place when the build
10949 failed. So let's say you're debugging a build failure in package
10950 @code{foo}; a typical session would look like this:
10953 $ guix build foo -K
10954 @dots{} @i{build fails}
10955 $ cd /tmp/guix-build-foo.drv-0
10956 $ source ./environment-variables
10960 Now, you can invoke commands as if you were the daemon (almost) and
10961 troubleshoot your build process.
10963 Sometimes it happens that, for example, a package's tests pass when you
10964 run them manually but they fail when the daemon runs them. This can
10965 happen because the daemon runs builds in containers where, unlike in our
10966 environment above, network access is missing, @file{/bin/sh} does not
10967 exist, etc. (@pxref{Build Environment Setup}).
10969 In such cases, you may need to run inspect the build process from within
10970 a container similar to the one the build daemon creates:
10973 $ guix build -K foo
10975 $ cd /tmp/guix-build-foo.drv-0
10976 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
10977 [env]# source ./environment-variables
10981 Here, @command{guix environment -C} creates a container and spawns a new
10982 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
10983 strace gdb} part adds the @command{strace} and @command{gdb} commands to
10984 the container, which you may find handy while debugging. The
10985 @option{--no-grafts} option makes sure we get the exact same
10986 environment, with ungrafted packages (@pxref{Security Updates}, for more
10989 To get closer to a container like that used by the build daemon, we can
10990 remove @file{/bin/sh}:
10996 (Don't worry, this is harmless: this is all happening in the throw-away
10997 container created by @command{guix environment}.)
10999 The @command{strace} command is probably not in the search path, but we
11003 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
11006 In this way, not only you will have reproduced the environment variables
11007 the daemon uses, you will also be running the build process in a container
11008 similar to the one the daemon uses.
11011 @node Invoking guix edit
11012 @section Invoking @command{guix edit}
11014 @cindex @command{guix edit}
11015 @cindex package definition, editing
11016 So many packages, so many source files! The @command{guix edit} command
11017 facilitates the life of users and packagers by pointing their editor at
11018 the source file containing the definition of the specified packages.
11022 guix edit gcc@@4.9 vim
11026 launches the program specified in the @env{VISUAL} or in the
11027 @env{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
11030 If you are using a Guix Git checkout (@pxref{Building from Git}), or
11031 have created your own packages on @env{GUIX_PACKAGE_PATH}
11032 (@pxref{Package Modules}), you will be able to edit the package
11033 recipes. In other cases, you will be able to examine the read-only recipes
11034 for packages currently in the store.
11036 Instead of @env{GUIX_PACKAGE_PATH}, the command-line option
11037 @option{--load-path=@var{directory}} (or in short @option{-L
11038 @var{directory}}) allows you to add @var{directory} to the front of the
11039 package module search path and so make your own packages visible.
11041 @node Invoking guix download
11042 @section Invoking @command{guix download}
11044 @cindex @command{guix download}
11045 @cindex downloading package sources
11046 When writing a package definition, developers typically need to download
11047 a source tarball, compute its SHA256 hash, and write that
11048 hash in the package definition (@pxref{Defining Packages}). The
11049 @command{guix download} tool helps with this task: it downloads a file
11050 from the given URI, adds it to the store, and prints both its file name
11051 in the store and its SHA256 hash.
11053 The fact that the downloaded file is added to the store saves bandwidth:
11054 when the developer eventually tries to build the newly defined package
11055 with @command{guix build}, the source tarball will not have to be
11056 downloaded again because it is already in the store. It is also a
11057 convenient way to temporarily stash files, which may be deleted
11058 eventually (@pxref{Invoking guix gc}).
11060 The @command{guix download} command supports the same URIs as used in
11061 package definitions. In particular, it supports @code{mirror://} URIs.
11062 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
11063 Guile bindings for GnuTLS are available in the user's environment; when
11064 they are not available, an error is raised. @xref{Guile Preparations,
11065 how to install the GnuTLS bindings for Guile,, gnutls-guile,
11066 GnuTLS-Guile}, for more information.
11068 @command{guix download} verifies HTTPS server certificates by loading
11069 the certificates of X.509 authorities from the directory pointed to by
11070 the @env{SSL_CERT_DIR} environment variable (@pxref{X.509
11071 Certificates}), unless @option{--no-check-certificate} is used.
11073 The following options are available:
11076 @item --hash=@var{algorithm}
11077 @itemx -H @var{algorithm}
11078 Compute a hash using the specified @var{algorithm}. @xref{Invoking guix
11079 hash}, for more information.
11081 @item --format=@var{fmt}
11082 @itemx -f @var{fmt}
11083 Write the hash in the format specified by @var{fmt}. For more
11084 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
11086 @item --no-check-certificate
11087 Do not validate the X.509 certificates of HTTPS servers.
11089 When using this option, you have @emph{absolutely no guarantee} that you
11090 are communicating with the authentic server responsible for the given
11091 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
11093 @item --output=@var{file}
11094 @itemx -o @var{file}
11095 Save the downloaded file to @var{file} instead of adding it to the
11099 @node Invoking guix hash
11100 @section Invoking @command{guix hash}
11102 @cindex @command{guix hash}
11103 The @command{guix hash} command computes the hash of a file.
11104 It is primarily a convenience tool for anyone contributing to the
11105 distribution: it computes the cryptographic hash of a file, which can be
11106 used in the definition of a package (@pxref{Defining Packages}).
11108 The general syntax is:
11111 guix hash @var{option} @var{file}
11114 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
11115 hash of data read from standard input. @command{guix hash} has the
11120 @item --hash=@var{algorithm}
11121 @itemx -H @var{algorithm}
11122 Compute a hash using the specified @var{algorithm}, @code{sha256} by
11125 @var{algorithm} must the name of a cryptographic hash algorithm
11126 supported by Libgcrypt @i{via} Guile-Gcrypt---e.g., @code{sha512} or
11127 @code{sha3-256} (@pxref{Hash Functions,,, guile-gcrypt, Guile-Gcrypt
11128 Reference Manual}).
11130 @item --format=@var{fmt}
11131 @itemx -f @var{fmt}
11132 Write the hash in the format specified by @var{fmt}.
11134 Supported formats: @code{base64}, @code{nix-base32}, @code{base32}, @code{base16}
11135 (@code{hex} and @code{hexadecimal} can be used as well).
11137 If the @option{--format} option is not specified, @command{guix hash}
11138 will output the hash in @code{nix-base32}. This representation is used
11139 in the definitions of packages.
11143 Compute the hash on @var{file} recursively.
11145 In this case, the hash is computed on an archive containing @var{file},
11146 including its children if it is a directory. Some of the metadata of
11147 @var{file} is part of the archive; for instance, when @var{file} is a
11148 regular file, the hash is different depending on whether @var{file} is
11149 executable or not. Metadata such as time stamps has no impact on the
11150 hash (@pxref{Invoking guix archive}).
11151 @c FIXME: Replace xref above with xref to an ``Archive'' section when
11154 @item --exclude-vcs
11156 When combined with @option{--recursive}, exclude version control system
11157 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.).
11160 As an example, here is how you would compute the hash of a Git checkout,
11161 which is useful when using the @code{git-fetch} method (@pxref{origin
11165 $ git clone http://example.org/foo.git
11171 @node Invoking guix import
11172 @section Invoking @command{guix import}
11174 @cindex importing packages
11175 @cindex package import
11176 @cindex package conversion
11177 @cindex Invoking @command{guix import}
11178 The @command{guix import} command is useful for people who would like to
11179 add a package to the distribution with as little work as
11180 possible---a legitimate demand. The command knows of a few
11181 repositories from which it can ``import'' package metadata. The result
11182 is a package definition, or a template thereof, in the format we know
11183 (@pxref{Defining Packages}).
11185 The general syntax is:
11188 guix import @var{importer} @var{options}@dots{}
11191 @var{importer} specifies the source from which to import package
11192 metadata, and @var{options} specifies a package identifier and other
11193 options specific to @var{importer}.
11195 Some of the importers rely on the ability to run the @command{gpgv} command.
11196 For these, GnuPG must be installed and in @code{$PATH}; run @code{guix install
11199 Currently, the available ``importers'' are:
11203 Import metadata for the given GNU package. This provides a template
11204 for the latest version of that GNU package, including the hash of its
11205 source tarball, and its canonical synopsis and description.
11207 Additional information such as the package dependencies and its
11208 license needs to be figured out manually.
11210 For example, the following command returns a package definition for
11214 guix import gnu hello
11217 Specific command-line options are:
11220 @item --key-download=@var{policy}
11221 As for @command{guix refresh}, specify the policy to handle missing
11222 OpenPGP keys when verifying the package signature. @xref{Invoking guix
11223 refresh, @option{--key-download}}.
11228 Import metadata from the @uref{https://pypi.python.org/, Python Package
11229 Index}. Information is taken from the JSON-formatted description
11230 available at @code{pypi.python.org} and usually includes all the relevant
11231 information, including package dependencies. For maximum efficiency, it
11232 is recommended to install the @command{unzip} utility, so that the
11233 importer can unzip Python wheels and gather data from them.
11235 The command below imports metadata for the @code{itsdangerous} Python
11239 guix import pypi itsdangerous
11245 Traverse the dependency graph of the given upstream package recursively
11246 and generate package expressions for all those packages that are not yet
11252 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
11253 is taken from the JSON-formatted description available at
11254 @code{rubygems.org} and includes most relevant information, including
11255 runtime dependencies. There are some caveats, however. The metadata
11256 doesn't distinguish between synopses and descriptions, so the same string
11257 is used for both fields. Additionally, the details of non-Ruby
11258 dependencies required to build native extensions is unavailable and left
11259 as an exercise to the packager.
11261 The command below imports metadata for the @code{rails} Ruby package:
11264 guix import gem rails
11270 Traverse the dependency graph of the given upstream package recursively
11271 and generate package expressions for all those packages that are not yet
11277 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
11278 Information is taken from the JSON-formatted metadata provided through
11279 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
11280 relevant information, such as module dependencies. License information
11281 should be checked closely. If Perl is available in the store, then the
11282 @code{corelist} utility will be used to filter core modules out of the
11283 list of dependencies.
11285 The command command below imports metadata for the Acme::Boolean Perl
11289 guix import cpan Acme::Boolean
11294 @cindex Bioconductor
11295 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
11296 central repository for the @uref{https://r-project.org, GNU@tie{}R
11297 statistical and graphical environment}.
11299 Information is extracted from the @file{DESCRIPTION} file of the package.
11301 The command command below imports metadata for the Cairo R package:
11304 guix import cran Cairo
11307 When @option{--recursive} is added, the importer will traverse the
11308 dependency graph of the given upstream package recursively and generate
11309 package expressions for all those packages that are not yet in Guix.
11311 When @option{--style=specification} is added, the importer will generate
11312 package definitions whose inputs are package specifications instead of
11313 references to package variables. This is useful when generated package
11314 definitions are to be appended to existing user modules, as the list of
11315 used package modules need not be changed. The default is
11316 @option{--style=variable}.
11318 When @option{--archive=bioconductor} is added, metadata is imported from
11319 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
11320 packages for the analysis and comprehension of high-throughput
11321 genomic data in bioinformatics.
11323 Information is extracted from the @file{DESCRIPTION} file contained in the
11326 The command below imports metadata for the GenomicRanges R package:
11329 guix import cran --archive=bioconductor GenomicRanges
11332 Finally, you can also import R packages that have not yet been published on
11333 CRAN or Bioconductor as long as they are in a git repository. Use
11334 @option{--archive=git} followed by the URL of the git repository:
11337 guix import cran --archive=git https://github.com/immunogenomics/harmony
11343 Import metadata from @uref{https://www.ctan.org/, CTAN}, the
11344 comprehensive TeX archive network for TeX packages that are part of the
11345 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
11347 Information about the package is obtained through the XML API provided
11348 by CTAN, while the source code is downloaded from the SVN repository of
11349 the Tex Live project. This is done because the CTAN does not keep
11350 versioned archives.
11352 The command command below imports metadata for the @code{fontspec}
11356 guix import texlive fontspec
11359 When @option{--archive=@var{directory}} is added, the source code is
11360 downloaded not from the @file{latex} sub-directory of the
11361 @file{texmf-dist/source} tree in the TeX Live SVN repository, but from
11362 the specified sibling @var{directory} under the same root.
11364 The command below imports metadata for the @code{ifxetex} package from
11365 CTAN while fetching the sources from the directory
11366 @file{texmf/source/generic}:
11369 guix import texlive --archive=generic ifxetex
11373 @cindex JSON, import
11374 Import package metadata from a local JSON file. Consider the following
11375 example package definition in JSON format:
11381 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
11382 "build-system": "gnu",
11383 "home-page": "https://www.gnu.org/software/hello/",
11384 "synopsis": "Hello, GNU world: An example GNU package",
11385 "description": "GNU Hello prints a greeting.",
11386 "license": "GPL-3.0+",
11387 "native-inputs": ["gettext"]
11391 The field names are the same as for the @code{<package>} record
11392 (@xref{Defining Packages}). References to other packages are provided
11393 as JSON lists of quoted package specification strings such as
11394 @code{guile} or @code{guile@@2.0}.
11396 The importer also supports a more explicit source definition using the
11397 common fields for @code{<origin>} records:
11403 "method": "url-fetch",
11404 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
11406 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
11413 The command below reads metadata from the JSON file @code{hello.json}
11414 and outputs a package expression:
11417 guix import json hello.json
11421 Import metadata from a local copy of the source of the
11422 @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
11423 relies on the @command{nix-instantiate} command of
11424 @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
11425 typically written in a mixture of Nix-language and Bash code. This
11426 command only imports the high-level package structure that is written in
11427 the Nix language. It normally includes all the basic fields of a
11428 package definition.
11430 When importing a GNU package, the synopsis and descriptions are replaced
11431 by their canonical upstream variant.
11433 Usually, you will first need to do:
11436 export NIX_REMOTE=daemon
11440 so that @command{nix-instantiate} does not try to open the Nix database.
11442 As an example, the command below imports the package definition of
11443 LibreOffice (more precisely, it imports the definition of the package
11444 bound to the @code{libreoffice} top-level attribute):
11447 guix import nix ~/path/to/nixpkgs libreoffice
11452 Import metadata from the Haskell community's central package archive
11453 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
11454 Cabal files and includes all the relevant information, including package
11457 Specific command-line options are:
11462 Read a Cabal file from standard input.
11463 @item --no-test-dependencies
11465 Do not include dependencies required only by the test suites.
11466 @item --cabal-environment=@var{alist}
11467 @itemx -e @var{alist}
11468 @var{alist} is a Scheme alist defining the environment in which the
11469 Cabal conditionals are evaluated. The accepted keys are: @code{os},
11470 @code{arch}, @code{impl} and a string representing the name of a flag.
11471 The value associated with a flag has to be either the symbol
11472 @code{true} or @code{false}. The value associated with other keys
11473 has to conform to the Cabal file format definition. The default value
11474 associated with the keys @code{os}, @code{arch} and @code{impl} is
11475 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
11478 Traverse the dependency graph of the given upstream package recursively
11479 and generate package expressions for all those packages that are not yet
11483 The command below imports metadata for the latest version of the
11484 HTTP Haskell package without including test dependencies and
11485 specifying the value of the flag @samp{network-uri} as @code{false}:
11488 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
11491 A specific package version may optionally be specified by following the
11492 package name by an at-sign and a version number as in the following example:
11495 guix import hackage mtl@@2.1.3.1
11500 The @code{stackage} importer is a wrapper around the @code{hackage} one.
11501 It takes a package name, looks up the package version included in a
11502 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
11503 release and uses the @code{hackage} importer to retrieve its metadata.
11504 Note that it is up to you to select an LTS release compatible with the
11505 GHC compiler used by Guix.
11507 Specific command-line options are:
11510 @item --no-test-dependencies
11512 Do not include dependencies required only by the test suites.
11513 @item --lts-version=@var{version}
11514 @itemx -l @var{version}
11515 @var{version} is the desired LTS release version. If omitted the latest
11519 Traverse the dependency graph of the given upstream package recursively
11520 and generate package expressions for all those packages that are not yet
11524 The command below imports metadata for the HTTP Haskell package
11525 included in the LTS Stackage release version 7.18:
11528 guix import stackage --lts-version=7.18 HTTP
11533 Import metadata from an Emacs Lisp Package Archive (ELPA) package
11534 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
11536 Specific command-line options are:
11539 @item --archive=@var{repo}
11540 @itemx -a @var{repo}
11541 @var{repo} identifies the archive repository from which to retrieve the
11542 information. Currently the supported repositories and their identifiers
11546 @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
11547 identifier. This is the default.
11549 Packages from @code{elpa.gnu.org} are signed with one of the keys
11550 contained in the GnuPG keyring at
11551 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
11552 @code{emacs} package (@pxref{Package Installation, ELPA package
11553 signatures,, emacs, The GNU Emacs Manual}).
11556 @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
11557 @code{melpa-stable} identifier.
11560 @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
11566 Traverse the dependency graph of the given upstream package recursively
11567 and generate package expressions for all those packages that are not yet
11573 Import metadata from the crates.io Rust package repository
11574 @uref{https://crates.io, crates.io}, as in this example:
11577 guix import crate blake2-rfc
11580 The crate importer also allows you to specify a version string:
11583 guix import crate constant-time-eq@@0.1.0
11586 Additional options include:
11591 Traverse the dependency graph of the given upstream package recursively
11592 and generate package expressions for all those packages that are not yet
11599 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
11600 repository used by the OCaml community.
11602 Additional options include:
11607 Traverse the dependency graph of the given upstream package recursively
11608 and generate package expressions for all those packages that are not yet
11611 Select the given repository (a repository name). Possible values include:
11613 @item @code{opam}, the default opam repository,
11614 @item @code{coq} or @code{coq-released}, the stable repository for coq packages,
11615 @item @code{coq-core-dev}, the repository that contains development versions of coq,
11616 @item @code{coq-extra-dev}, the repository that contains development versions
11623 Import metadata for a Go module using
11624 @uref{https://proxy.golang.org, proxy.golang.org}.
11627 guix import go gopkg.in/yaml.v2
11630 It is possible to use a package specification with a @code{@@VERSION}
11631 suffix to import a specific version.
11633 Additional options include:
11638 Traverse the dependency graph of the given upstream package recursively
11639 and generate package expressions for all those packages that are not yet
11641 @item --pin-versions
11642 When using this option, the importer preserves the exact versions of the
11643 Go modules dependencies instead of using their latest available
11644 versions. This can be useful when attempting to import packages that
11645 recursively depend on former versions of themselves to build. When
11646 using this mode, the symbol of the package is made by appending the
11647 version to its name, so that multiple versions of the same package can
11652 The structure of the @command{guix import} code is modular. It would be
11653 useful to have more importers for other package formats, and your help
11654 is welcome here (@pxref{Contributing}).
11656 @node Invoking guix refresh
11657 @section Invoking @command{guix refresh}
11659 @cindex @command {guix refresh}
11660 The primary audience of the @command{guix refresh} command is packagers.
11661 As a user, you may be interested in the @option{--with-latest} option,
11662 which can bring you package update superpowers built upon @command{guix
11663 refresh} (@pxref{Package Transformation Options,
11664 @option{--with-latest}}). By default, @command{guix refresh} reports
11665 any packages provided by the distribution that are outdated compared to
11666 the latest upstream version, like this:
11670 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
11671 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
11674 Alternatively, one can specify packages to consider, in which case a
11675 warning is emitted for packages that lack an updater:
11678 $ guix refresh coreutils guile guile-ssh
11679 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
11680 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
11683 @command{guix refresh} browses the upstream repository of each package and determines
11684 the highest version number of the releases therein. The command
11685 knows how to update specific types of packages: GNU packages, ELPA
11686 packages, etc.---see the documentation for @option{--type} below. There
11687 are many packages, though, for which it lacks a method to determine
11688 whether a new upstream release is available. However, the mechanism is
11689 extensible, so feel free to get in touch with us to add a new method!
11694 Consider the packages specified, and all the packages upon which they depend.
11697 $ guix refresh --recursive coreutils
11698 gnu/packages/acl.scm:40:13: acl would be upgraded from 2.2.53 to 2.3.1
11699 gnu/packages/m4.scm:30:12: 1.4.18 is already the latest version of m4
11700 gnu/packages/xml.scm:68:2: warning: no updater for expat
11701 gnu/packages/multiprecision.scm:40:12: 6.1.2 is already the latest version of gmp
11707 Sometimes the upstream name differs from the package name used in Guix,
11708 and @command{guix refresh} needs a little help. Most updaters honor the
11709 @code{upstream-name} property in package definitions, which can be used
11713 (define-public network-manager
11715 (name "network-manager")
11717 (properties '((upstream-name . "NetworkManager")))))
11720 When passed @option{--update}, it modifies distribution source files to
11721 update the version numbers and source tarball hashes of those package
11722 recipes (@pxref{Defining Packages}). This is achieved by downloading
11723 each package's latest source tarball and its associated OpenPGP
11724 signature, authenticating the downloaded tarball against its signature
11725 using @command{gpgv}, and finally computing its hash---note that GnuPG must be
11726 installed and in @code{$PATH}; run @code{guix install gnupg} if needed.
11729 key used to sign the tarball is missing from the user's keyring, an
11730 attempt is made to automatically retrieve it from a public key server;
11731 when this is successful, the key is added to the user's keyring; otherwise,
11732 @command{guix refresh} reports an error.
11734 The following options are supported:
11738 @item --expression=@var{expr}
11739 @itemx -e @var{expr}
11740 Consider the package @var{expr} evaluates to.
11742 This is useful to precisely refer to a package, as in this example:
11745 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
11748 This command lists the dependents of the ``final'' libc (essentially all
11753 Update distribution source files (package recipes) in place. This is
11754 usually run from a checkout of the Guix source tree (@pxref{Running
11755 Guix Before It Is Installed}):
11758 $ ./pre-inst-env guix refresh -s non-core -u
11761 @xref{Defining Packages}, for more information on package definitions.
11763 @item --select=[@var{subset}]
11764 @itemx -s @var{subset}
11765 Select all the packages in @var{subset}, one of @code{core} or
11768 The @code{core} subset refers to all the packages at the core of the
11769 distribution---i.e., packages that are used to build ``everything
11770 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
11771 changing one of these packages in the distribution entails a rebuild of
11772 all the others. Thus, such updates are an inconvenience to users in
11773 terms of build time or bandwidth used to achieve the upgrade.
11775 The @code{non-core} subset refers to the remaining packages. It is
11776 typically useful in cases where an update of the core packages would be
11779 @item --manifest=@var{file}
11780 @itemx -m @var{file}
11781 Select all the packages from the manifest in @var{file}. This is useful to
11782 check if any packages of the user manifest can be updated.
11784 @item --type=@var{updater}
11785 @itemx -t @var{updater}
11786 Select only packages handled by @var{updater} (may be a comma-separated
11787 list of updaters). Currently, @var{updater} may be one of:
11791 the updater for GNU packages;
11793 the updater for packages hosted at @uref{https://savannah.gnu.org, Savannah};
11795 the updater for packages hosted at @uref{https://sourceforge.net, SourceForge};
11797 the updater for GNOME packages;
11799 the updater for KDE packages;
11801 the updater for X.org packages;
11803 the updater for packages hosted on kernel.org;
11805 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
11807 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
11809 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
11811 the updater for @uref{https://www.cpan.org/, CPAN} packages;
11813 the updater for @uref{https://pypi.python.org, PyPI} packages.
11815 the updater for @uref{https://rubygems.org, RubyGems} packages.
11817 the updater for @uref{https://github.com, GitHub} packages.
11819 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
11821 the updater for @uref{https://www.stackage.org, Stackage} packages.
11823 the updater for @uref{https://crates.io, Crates} packages.
11825 the updater for @uref{https://launchpad.net, Launchpad} packages.
11827 a generic updater that crawls the HTML page where the source tarball of
11828 the package is hosted, when applicable.
11831 For instance, the following command only checks for updates of Emacs
11832 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
11835 $ guix refresh --type=elpa,cran
11836 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
11837 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
11840 @item --list-updaters
11842 List available updaters and exit (see @option{--type} above).
11844 For each updater, display the fraction of packages it covers; at the
11845 end, display the fraction of packages covered by all these updaters.
11848 In addition, @command{guix refresh} can be passed one or more package
11849 names, as in this example:
11852 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
11856 The command above specifically updates the @code{emacs} and
11857 @code{idutils} packages. The @option{--select} option would have no
11858 effect in this case. You might also want to update definitions that
11859 correspond to the packages installed in your profile:
11862 $ ./pre-inst-env guix refresh -u \
11863 $(guix package --list-installed | cut -f1)
11866 When considering whether to upgrade a package, it is sometimes
11867 convenient to know which packages would be affected by the upgrade and
11868 should be checked for compatibility. For this the following option may
11869 be used when passing @command{guix refresh} one or more package names:
11873 @item --list-dependent
11875 List top-level dependent packages that would need to be rebuilt as a
11876 result of upgrading one or more packages.
11878 @xref{Invoking guix graph, the @code{reverse-package} type of
11879 @command{guix graph}}, for information on how to visualize the list of
11880 dependents of a package.
11884 Be aware that the @option{--list-dependent} option only
11885 @emph{approximates} the rebuilds that would be required as a result of
11886 an upgrade. More rebuilds might be required under some circumstances.
11889 $ guix refresh --list-dependent flex
11890 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
11891 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
11894 The command above lists a set of packages that could be built to check
11895 for compatibility with an upgraded @code{flex} package.
11899 @item --list-transitive
11900 List all the packages which one or more packages depend upon.
11903 $ guix refresh --list-transitive flex
11904 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
11905 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{}
11910 The command above lists a set of packages which, when changed, would cause
11911 @code{flex} to be rebuilt.
11913 The following options can be used to customize GnuPG operation:
11917 @item --gpg=@var{command}
11918 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
11919 for in @code{$PATH}.
11921 @item --keyring=@var{file}
11922 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
11923 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
11924 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
11925 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
11926 information on a tool to manipulate keybox files).
11928 When this option is omitted, @command{guix refresh} uses
11929 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
11930 signing keys. OpenPGP signatures are checked against keys from this keyring;
11931 missing keys are downloaded to this keyring as well (see
11932 @option{--key-download} below).
11934 You can export keys from your default GPG keyring into a keybox file using
11935 commands like this one:
11938 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
11941 Likewise, you can fetch keys to a specific keybox file like this:
11944 gpg --no-default-keyring --keyring mykeyring.kbx \
11945 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
11948 @xref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
11949 Privacy Guard}, for more information on GPG's @option{--keyring} option.
11951 @item --key-download=@var{policy}
11952 Handle missing OpenPGP keys according to @var{policy}, which may be one
11957 Always download missing OpenPGP keys from the key server, and add them
11958 to the user's GnuPG keyring.
11961 Never try to download missing OpenPGP keys. Instead just bail out.
11964 When a package signed with an unknown OpenPGP key is encountered, ask
11965 the user whether to download it or not. This is the default behavior.
11968 @item --key-server=@var{host}
11969 Use @var{host} as the OpenPGP key server when importing a public key.
11971 @item --load-path=@var{directory}
11972 Add @var{directory} to the front of the package module search path
11973 (@pxref{Package Modules}).
11975 This allows users to define their own packages and make them visible to
11976 the command-line tools.
11980 The @code{github} updater uses the
11981 @uref{https://developer.github.com/v3/, GitHub API} to query for new
11982 releases. When used repeatedly e.g.@: when refreshing all packages,
11983 GitHub will eventually refuse to answer any further API requests. By
11984 default 60 API requests per hour are allowed, and a full refresh on all
11985 GitHub packages in Guix requires more than this. Authentication with
11986 GitHub through the use of an API token alleviates these limits. To use
11987 an API token, set the environment variable @env{GUIX_GITHUB_TOKEN} to a
11988 token procured from @uref{https://github.com/settings/tokens} or
11992 @node Invoking guix lint
11993 @section Invoking @command{guix lint}
11995 @cindex @command{guix lint}
11996 @cindex package, checking for errors
11997 The @command{guix lint} command is meant to help package developers avoid
11998 common errors and use a consistent style. It runs a number of checks on
11999 a given set of packages in order to find common mistakes in their
12000 definitions. Available @dfn{checkers} include (see
12001 @option{--list-checkers} for a complete list):
12006 Validate certain typographical and stylistic rules about package
12007 descriptions and synopses.
12009 @item inputs-should-be-native
12010 Identify inputs that should most likely be native inputs.
12016 @itemx source-file-name
12017 Probe @code{home-page} and @code{source} URLs and report those that are
12018 invalid. Suggest a @code{mirror://} URL when applicable. If the
12019 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
12020 URL@. Check that the source file name is meaningful, e.g.@: is not just a
12021 version number or ``git-checkout'', without a declared @code{file-name}
12022 (@pxref{origin Reference}).
12024 @item source-unstable-tarball
12025 Parse the @code{source} URL to determine if a tarball from GitHub is
12026 autogenerated or if it is a release tarball. Unfortunately GitHub's
12027 autogenerated tarballs are sometimes regenerated.
12030 Check that the derivation of the given packages can be successfully
12031 computed for all the supported systems (@pxref{Derivations}).
12033 @item profile-collisions
12034 Check whether installing the given packages in a profile would lead to
12035 collisions. Collisions occur when several packages with the same name
12036 but a different version or a different store file name are propagated.
12037 @xref{package Reference, @code{propagated-inputs}}, for more information
12038 on propagated inputs.
12041 @cindex Software Heritage, source code archive
12042 @cindex archival of source code, Software Heritage
12043 Checks whether the package's source code is archived at
12044 @uref{https://www.softwareheritage.org, Software Heritage}.
12046 When the source code that is not archived comes from a version-control system
12047 (VCS)---e.g., it's obtained with @code{git-fetch}, send Software Heritage a
12048 ``save'' request so that it eventually archives it. This ensures that the
12049 source will remain available in the long term, and that Guix can fall back to
12050 Software Heritage should the source code disappear from its original host.
12051 The status of recent ``save'' requests can be
12052 @uref{https://archive.softwareheritage.org/save/#requests, viewed on-line}.
12054 When source code is a tarball obtained with @code{url-fetch}, simply print a
12055 message when it is not archived. As of this writing, Software Heritage does
12056 not allow requests to save arbitrary tarballs; we are working on ways to
12057 ensure that non-VCS source code is also archived.
12060 @uref{https://archive.softwareheritage.org/api/#rate-limiting, limits the
12061 request rate per IP address}. When the limit is reached, @command{guix lint}
12062 prints a message and the @code{archival} checker stops doing anything until
12063 that limit has been reset.
12066 @cindex security vulnerabilities
12067 @cindex CVE, Common Vulnerabilities and Exposures
12068 Report known vulnerabilities found in the Common Vulnerabilities and
12069 Exposures (CVE) databases of the current and past year
12070 @uref{https://nvd.nist.gov/vuln/data-feeds, published by the US
12073 To view information about a particular vulnerability, visit pages such as:
12077 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
12079 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
12083 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
12084 @code{CVE-2015-7554}.
12086 Package developers can specify in package recipes the
12087 @uref{https://nvd.nist.gov/products/cpe,Common Platform Enumeration (CPE)}
12088 name and version of the package when they differ from the name or version
12089 that Guix uses, as in this example:
12095 ;; CPE calls this package "grub2".
12096 (properties '((cpe-name . "grub2")
12097 (cpe-version . "2.3"))))
12100 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
12101 Some entries in the CVE database do not specify which version of a
12102 package they apply to, and would thus ``stick around'' forever. Package
12103 developers who found CVE alerts and verified they can be ignored can
12104 declare them as in this example:
12110 ;; These CVEs no longer apply and can be safely ignored.
12111 (properties `((lint-hidden-cve . ("CVE-2011-0433"
12114 "CVE-2011-5244")))))
12118 Warn about obvious source code formatting issues: trailing white space,
12119 use of tabulations, etc.
12122 The general syntax is:
12125 guix lint @var{options} @var{package}@dots{}
12128 If no package is given on the command line, then all packages are checked.
12129 The @var{options} may be zero or more of the following:
12132 @item --list-checkers
12134 List and describe all the available checkers that will be run on packages
12139 Only enable the checkers specified in a comma-separated list using the
12140 names returned by @option{--list-checkers}.
12144 Only disable the checkers specified in a comma-separated list using the
12145 names returned by @option{--list-checkers}.
12149 Only enable the checkers that do not depend on Internet access.
12151 @item --load-path=@var{directory}
12152 @itemx -L @var{directory}
12153 Add @var{directory} to the front of the package module search path
12154 (@pxref{Package Modules}).
12156 This allows users to define their own packages and make them visible to
12157 the command-line tools.
12161 @node Invoking guix size
12162 @section Invoking @command{guix size}
12165 @cindex package size
12167 @cindex @command{guix size}
12168 The @command{guix size} command helps package developers profile the
12169 disk usage of packages. It is easy to overlook the impact of an
12170 additional dependency added to a package, or the impact of using a
12171 single output for a package that could easily be split (@pxref{Packages
12172 with Multiple Outputs}). Such are the typical issues that
12173 @command{guix size} can highlight.
12175 The command can be passed one or more package specifications
12176 such as @code{gcc@@4.8}
12177 or @code{guile:debug}, or a file name in the store. Consider this
12181 $ guix size coreutils
12182 store item total self
12183 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
12184 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
12185 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
12186 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
12187 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
12188 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
12189 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
12190 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
12195 The store items listed here constitute the @dfn{transitive closure} of
12196 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
12197 would be returned by:
12200 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
12203 Here the output shows three columns next to store items. The first column,
12204 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
12205 the store item---that is, its own size plus the size of all its
12206 dependencies. The next column, labeled ``self'', shows the size of the
12207 item itself. The last column shows the ratio of the size of the item
12208 itself to the space occupied by all the items listed here.
12210 In this example, we see that the closure of Coreutils weighs in at
12211 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
12212 libraries. (That libc and GCC's libraries represent a large fraction of
12213 the closure is not a problem @i{per se} because they are always available
12214 on the system anyway.)
12216 Since the command also accepts store file names, assessing the size of
12217 a build result is straightforward:
12220 guix size $(guix system build config.scm)
12223 When the package(s) passed to @command{guix size} are available in the
12224 store@footnote{More precisely, @command{guix size} looks for the
12225 @emph{ungrafted} variant of the given package(s), as returned by
12226 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
12227 for information on grafts.}, @command{guix size} queries the daemon to determine its
12228 dependencies, and measures its size in the store, similar to @command{du
12229 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
12232 When the given packages are @emph{not} in the store, @command{guix size}
12233 reports information based on the available substitutes
12234 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
12235 store items that are not even on disk, only available remotely.
12237 You can also specify several package names:
12240 $ guix size coreutils grep sed bash
12241 store item total self
12242 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
12243 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
12244 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
12245 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
12251 In this example we see that the combination of the four packages takes
12252 102.3@tie{}MiB in total, which is much less than the sum of each closure
12253 since they have a lot of dependencies in common.
12255 When looking at the profile returned by @command{guix size}, you may
12256 find yourself wondering why a given package shows up in the profile at
12257 all. To understand it, you can use @command{guix graph --path -t
12258 references} to display the shortest path between the two packages
12259 (@pxref{Invoking guix graph}).
12261 The available options are:
12265 @item --substitute-urls=@var{urls}
12266 Use substitute information from @var{urls}.
12267 @xref{client-substitute-urls, the same option for @code{guix build}}.
12269 @item --sort=@var{key}
12270 Sort lines according to @var{key}, one of the following options:
12274 the size of each item (the default);
12276 the total size of the item's closure.
12279 @item --map-file=@var{file}
12280 Write a graphical map of disk usage in PNG format to @var{file}.
12282 For the example above, the map looks like this:
12284 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
12285 produced by @command{guix size}}
12287 This option requires that
12288 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
12289 installed and visible in Guile's module search path. When that is not
12290 the case, @command{guix size} fails as it tries to load it.
12292 @item --system=@var{system}
12293 @itemx -s @var{system}
12294 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
12296 @item --load-path=@var{directory}
12297 @itemx -L @var{directory}
12298 Add @var{directory} to the front of the package module search path
12299 (@pxref{Package Modules}).
12301 This allows users to define their own packages and make them visible to
12302 the command-line tools.
12305 @node Invoking guix graph
12306 @section Invoking @command{guix graph}
12309 @cindex @command{guix graph}
12310 @cindex package dependencies
12311 Packages and their dependencies form a @dfn{graph}, specifically a
12312 directed acyclic graph (DAG). It can quickly become difficult to have a
12313 mental model of the package DAG, so the @command{guix graph} command
12314 provides a visual representation of the DAG@. By default,
12315 @command{guix graph} emits a DAG representation in the input format of
12316 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
12317 directly to the @command{dot} command of Graphviz. It can also emit an
12318 HTML page with embedded JavaScript code to display a ``chord diagram''
12319 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
12320 emit Cypher queries to construct a graph in a graph database supporting
12321 the @uref{https://www.opencypher.org/, openCypher} query language. With
12322 @option{--path}, it simply displays the shortest path between two
12323 packages. The general syntax is:
12326 guix graph @var{options} @var{package}@dots{}
12329 For example, the following command generates a PDF file representing the
12330 package DAG for the GNU@tie{}Core Utilities, showing its build-time
12334 guix graph coreutils | dot -Tpdf > dag.pdf
12337 The output looks like this:
12339 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
12341 Nice little graph, no?
12343 You may find it more pleasant to navigate the graph interactively with
12344 @command{xdot} (from the @code{xdot} package):
12347 guix graph coreutils | xdot -
12350 But there is more than one graph! The one above is concise: it is the
12351 graph of package objects, omitting implicit inputs such as GCC, libc,
12352 grep, etc. It is often useful to have such a concise graph, but
12353 sometimes one may want to see more details. @command{guix graph} supports
12354 several types of graphs, allowing you to choose the level of detail:
12358 This is the default type used in the example above. It shows the DAG of
12359 package objects, excluding implicit dependencies. It is concise, but
12360 filters out many details.
12362 @item reverse-package
12363 This shows the @emph{reverse} DAG of packages. For example:
12366 guix graph --type=reverse-package ocaml
12369 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
12370 you are also interested in cases where OCaml is an implicit dependency, see
12371 @code{reverse-bag} below).
12373 Note that for core packages this can yield huge graphs. If all you want
12374 is to know the number of packages that depend on a given package, use
12375 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
12376 @option{--list-dependent}}).
12379 This is the package DAG, @emph{including} implicit inputs.
12381 For instance, the following command:
12384 guix graph --type=bag-emerged coreutils
12387 ...@: yields this bigger graph:
12389 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
12391 At the bottom of the graph, we see all the implicit inputs of
12392 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
12394 Now, note that the dependencies of these implicit inputs---that is, the
12395 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
12396 here, for conciseness.
12399 Similar to @code{bag-emerged}, but this time including all the bootstrap
12402 @item bag-with-origins
12403 Similar to @code{bag}, but also showing origins and their dependencies.
12406 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
12407 it also takes implicit dependencies into account. For example:
12410 guix graph -t reverse-bag dune
12414 ...@: yields the graph of all packages that depend on Dune, directly or
12415 indirectly. Since Dune is an @emph{implicit} dependency of many packages
12416 @i{via} @code{dune-build-system}, this shows a large number of packages,
12417 whereas @code{reverse-package} would show very few if any.
12420 This is the most detailed representation: It shows the DAG of
12421 derivations (@pxref{Derivations}) and plain store items. Compared to
12422 the above representation, many additional nodes are visible, including
12423 build scripts, patches, Guile modules, etc.
12425 For this type of graph, it is also possible to pass a @file{.drv} file
12426 name instead of a package name, as in:
12429 guix graph -t derivation $(guix system build -d my-config.scm)
12433 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
12434 For example, the following command shows the graph for the package
12435 module that defines the @code{guile} package:
12438 guix graph -t module guile | xdot -
12442 All the types above correspond to @emph{build-time dependencies}. The
12443 following graph type represents the @emph{run-time dependencies}:
12447 This is the graph of @dfn{references} of a package output, as returned
12448 by @command{guix gc --references} (@pxref{Invoking guix gc}).
12450 If the given package output is not available in the store, @command{guix
12451 graph} attempts to obtain dependency information from substitutes.
12453 Here you can also pass a store file name instead of a package name. For
12454 example, the command below produces the reference graph of your profile
12455 (which can be big!):
12458 guix graph -t references $(readlink -f ~/.guix-profile)
12462 This is the graph of the @dfn{referrers} of a store item, as returned by
12463 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
12465 This relies exclusively on local information from your store. For
12466 instance, let us suppose that the current Inkscape is available in 10
12467 profiles on your machine; @command{guix graph -t referrers inkscape}
12468 will show a graph rooted at Inkscape and with those 10 profiles linked
12471 It can help determine what is preventing a store item from being garbage
12476 @cindex shortest path, between packages
12477 Often, the graph of the package you are interested in does not fit on
12478 your screen, and anyway all you want to know is @emph{why} that package
12479 actually depends on some seemingly unrelated package. The
12480 @option{--path} option instructs @command{guix graph} to display the
12481 shortest path between two packages (or derivations, or store items,
12485 $ guix graph --path emacs libunistring
12488 libunistring@@0.9.10
12489 $ guix graph --path -t derivation emacs libunistring
12490 /gnu/store/@dots{}-emacs-26.3.drv
12491 /gnu/store/@dots{}-mailutils-3.9.drv
12492 /gnu/store/@dots{}-libunistring-0.9.10.drv
12493 $ guix graph --path -t references emacs libunistring
12494 /gnu/store/@dots{}-emacs-26.3
12495 /gnu/store/@dots{}-libidn2-2.2.0
12496 /gnu/store/@dots{}-libunistring-0.9.10
12499 The available options are the following:
12502 @item --type=@var{type}
12503 @itemx -t @var{type}
12504 Produce a graph output of @var{type}, where @var{type} must be one of
12505 the values listed above.
12508 List the supported graph types.
12510 @item --backend=@var{backend}
12511 @itemx -b @var{backend}
12512 Produce a graph using the selected @var{backend}.
12514 @item --list-backends
12515 List the supported graph backends.
12517 Currently, the available backends are Graphviz and d3.js.
12520 Display the shortest path between two nodes of the type specified by
12521 @option{--type}. The example below shows the shortest path between
12522 @code{libreoffice} and @code{llvm} according to the references of
12523 @code{libreoffice}:
12526 $ guix graph --path -t references libreoffice llvm
12527 /gnu/store/@dots{}-libreoffice-6.4.2.2
12528 /gnu/store/@dots{}-libepoxy-1.5.4
12529 /gnu/store/@dots{}-mesa-19.3.4
12530 /gnu/store/@dots{}-llvm-9.0.1
12533 @item --expression=@var{expr}
12534 @itemx -e @var{expr}
12535 Consider the package @var{expr} evaluates to.
12537 This is useful to precisely refer to a package, as in this example:
12540 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
12543 @item --system=@var{system}
12544 @itemx -s @var{system}
12545 Display the graph for @var{system}---e.g., @code{i686-linux}.
12547 The package dependency graph is largely architecture-independent, but there
12548 are some architecture-dependent bits that this option allows you to visualize.
12550 @item --load-path=@var{directory}
12551 @itemx -L @var{directory}
12552 Add @var{directory} to the front of the package module search path
12553 (@pxref{Package Modules}).
12555 This allows users to define their own packages and make them visible to
12556 the command-line tools.
12559 On top of that, @command{guix graph} supports all the usual package
12560 transformation options (@pxref{Package Transformation Options}). This
12561 makes it easy to view the effect of a graph-rewriting transformation
12562 such as @option{--with-input}. For example, the command below outputs
12563 the graph of @code{git} once @code{openssl} has been replaced by
12564 @code{libressl} everywhere in the graph:
12567 guix graph git --with-input=openssl=libressl
12570 So many possibilities, so much fun!
12572 @node Invoking guix publish
12573 @section Invoking @command{guix publish}
12575 @cindex @command{guix publish}
12576 The purpose of @command{guix publish} is to enable users to easily share
12577 their store with others, who can then use it as a substitute server
12578 (@pxref{Substitutes}).
12580 When @command{guix publish} runs, it spawns an HTTP server which allows
12581 anyone with network access to obtain substitutes from it. This means
12582 that any machine running Guix can also act as if it were a build farm,
12583 since the HTTP interface is compatible with Cuirass, the software behind
12584 the @code{@value{SUBSTITUTE-SERVER}} build farm.
12586 For security, each substitute is signed, allowing recipients to check
12587 their authenticity and integrity (@pxref{Substitutes}). Because
12588 @command{guix publish} uses the signing key of the system, which is only
12589 readable by the system administrator, it must be started as root; the
12590 @option{--user} option makes it drop root privileges early on.
12592 The signing key pair must be generated before @command{guix publish} is
12593 launched, using @command{guix archive --generate-key} (@pxref{Invoking
12596 When the @option{--advertise} option is passed, the server advertises
12597 its availability on the local network using multicast DNS (mDNS) and DNS
12598 service discovery (DNS-SD), currently @i{via} Guile-Avahi (@pxref{Top,,,
12599 guile-avahi, Using Avahi in Guile Scheme Programs}).
12601 The general syntax is:
12604 guix publish @var{options}@dots{}
12607 Running @command{guix publish} without any additional arguments will
12608 spawn an HTTP server on port 8080:
12614 Once a publishing server has been authorized, the daemon may download
12615 substitutes from it. @xref{Getting Substitutes from Other Servers}.
12617 By default, @command{guix publish} compresses archives on the fly as it
12618 serves them. This ``on-the-fly'' mode is convenient in that it requires
12619 no setup and is immediately available. However, when serving lots of
12620 clients, we recommend using the @option{--cache} option, which enables
12621 caching of the archives before they are sent to clients---see below for
12622 details. The @command{guix weather} command provides a handy way to
12623 check what a server provides (@pxref{Invoking guix weather}).
12625 As a bonus, @command{guix publish} also serves as a content-addressed
12626 mirror for source files referenced in @code{origin} records
12627 (@pxref{origin Reference}). For instance, assuming @command{guix
12628 publish} is running on @code{example.org}, the following URL returns the
12629 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
12630 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
12633 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
12636 Obviously, these URLs only work for files that are in the store; in
12637 other cases, they return 404 (``Not Found'').
12639 @cindex build logs, publication
12640 Build logs are available from @code{/log} URLs like:
12643 http://example.org/log/gwspk@dots{}-guile-2.2.3
12647 When @command{guix-daemon} is configured to save compressed build logs,
12648 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
12649 URLs return the compressed log as-is, with an appropriate
12650 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
12651 running @command{guix-daemon} with @option{--log-compression=gzip} since
12652 Web browsers can automatically decompress it, which is not the case with
12655 The following options are available:
12658 @item --port=@var{port}
12659 @itemx -p @var{port}
12660 Listen for HTTP requests on @var{port}.
12662 @item --listen=@var{host}
12663 Listen on the network interface for @var{host}. The default is to
12664 accept connections from any interface.
12666 @item --user=@var{user}
12667 @itemx -u @var{user}
12668 Change privileges to @var{user} as soon as possible---i.e., once the
12669 server socket is open and the signing key has been read.
12671 @item --compression[=@var{method}[:@var{level}]]
12672 @itemx -C [@var{method}[:@var{level}]]
12673 Compress data using the given @var{method} and @var{level}. @var{method} is
12674 one of @code{lzip}, @code{zstd}, and @code{gzip}; when @var{method} is
12675 omitted, @code{gzip} is used.
12677 When @var{level} is zero, disable compression. The range 1 to 9 corresponds
12678 to different compression levels: 1 is the fastest, and 9 is the best
12679 (CPU-intensive). The default is 3.
12681 Usually, @code{lzip} compresses noticeably better than @code{gzip} for a
12682 small increase in CPU usage; see
12683 @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip
12684 Web page}. However, @code{lzip} achieves low decompression throughput
12685 (on the order of 50@tie{}MiB/s on modern hardware), which can be a
12686 bottleneck for someone who downloads over a fast network connection.
12688 The compression ratio of @code{zstd} is between that of @code{lzip} and
12689 that of @code{gzip}; its main advantage is a
12690 @uref{https://facebook.github.io/zstd/,high decompression speed}.
12692 Unless @option{--cache} is used, compression occurs on the fly and
12693 the compressed streams are not
12694 cached. Thus, to reduce load on the machine that runs @command{guix
12695 publish}, it may be a good idea to choose a low compression level, to
12696 run @command{guix publish} behind a caching proxy, or to use
12697 @option{--cache}. Using @option{--cache} has the advantage that it
12698 allows @command{guix publish} to add @code{Content-Length} HTTP header
12701 This option can be repeated, in which case every substitute gets compressed
12702 using all the selected methods, and all of them are advertised. This is
12703 useful when users may not support all the compression methods: they can select
12704 the one they support.
12706 @item --cache=@var{directory}
12707 @itemx -c @var{directory}
12708 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
12709 and only serve archives that are in cache.
12711 When this option is omitted, archives and meta-data are created
12712 on-the-fly. This can reduce the available bandwidth, especially when
12713 compression is enabled, since this may become CPU-bound. Another
12714 drawback of the default mode is that the length of archives is not known
12715 in advance, so @command{guix publish} does not add a
12716 @code{Content-Length} HTTP header to its responses, which in turn
12717 prevents clients from knowing the amount of data being downloaded.
12719 Conversely, when @option{--cache} is used, the first request for a store
12720 item (@i{via} a @code{.narinfo} URL) triggers a
12721 background process to @dfn{bake} the archive---computing its
12722 @code{.narinfo} and compressing the archive, if needed. Once the
12723 archive is cached in @var{directory}, subsequent requests succeed and
12724 are served directly from the cache, which guarantees that clients get
12725 the best possible bandwidth.
12727 That first @code{.narinfo} request nonetheless returns 200, provided the
12728 requested store item is ``small enough'', below the cache bypass
12729 threshold---see @option{--cache-bypass-threshold} below. That way,
12730 clients do not have to wait until the archive is baked. For larger
12731 store items, the first @code{.narinfo} request returns 404, meaning that
12732 clients have to wait until the archive is baked.
12734 The ``baking'' process is performed by worker threads. By default, one
12735 thread per CPU core is created, but this can be customized. See
12736 @option{--workers} below.
12738 When @option{--ttl} is used, cached entries are automatically deleted
12739 when they have expired.
12741 @item --workers=@var{N}
12742 When @option{--cache} is used, request the allocation of @var{N} worker
12743 threads to ``bake'' archives.
12745 @item --ttl=@var{ttl}
12746 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
12747 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
12748 days, @code{1m} means 1 month, and so on.
12750 This allows the user's Guix to keep substitute information in cache for
12751 @var{ttl}. However, note that @code{guix publish} does not itself
12752 guarantee that the store items it provides will indeed remain available
12753 for as long as @var{ttl}.
12755 Additionally, when @option{--cache} is used, cached entries that have
12756 not been accessed for @var{ttl} and that no longer have a corresponding
12757 item in the store, may be deleted.
12759 @item --cache-bypass-threshold=@var{size}
12760 When used in conjunction with @option{--cache}, store items smaller than
12761 @var{size} are immediately available, even when they are not yet in
12762 cache. @var{size} is a size in bytes, or it can be suffixed by @code{M}
12763 for megabytes and so on. The default is @code{10M}.
12765 ``Cache bypass'' allows you to reduce the publication delay for clients
12766 at the expense of possibly additional I/O and CPU use on the server
12767 side: depending on the client access patterns, those store items can end
12768 up being baked several times until a copy is available in cache.
12770 Increasing the threshold may be useful for sites that have few users, or
12771 to guarantee that users get substitutes even for store items that are
12774 @item --nar-path=@var{path}
12775 Use @var{path} as the prefix for the URLs of ``nar'' files
12776 (@pxref{Invoking guix archive, normalized archives}).
12778 By default, nars are served at a URL such as
12779 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
12780 change the @code{/nar} part to @var{path}.
12782 @item --public-key=@var{file}
12783 @itemx --private-key=@var{file}
12784 Use the specific @var{file}s as the public/private key pair used to sign
12785 the store items being published.
12787 The files must correspond to the same key pair (the private key is used
12788 for signing and the public key is merely advertised in the signature
12789 metadata). They must contain keys in the canonical s-expression format
12790 as produced by @command{guix archive --generate-key} (@pxref{Invoking
12791 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
12792 @file{/etc/guix/signing-key.sec} are used.
12794 @item --repl[=@var{port}]
12795 @itemx -r [@var{port}]
12796 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
12797 Reference Manual}) on @var{port} (37146 by default). This is used
12798 primarily for debugging a running @command{guix publish} server.
12801 Enabling @command{guix publish} on Guix System is a one-liner: just
12802 instantiate a @code{guix-publish-service-type} service in the @code{services} field
12803 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
12804 @code{guix-publish-service-type}}).
12806 If you are instead running Guix on a ``foreign distro'', follow these
12811 If your host distro uses the systemd init system:
12814 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
12815 /etc/systemd/system/
12816 # systemctl start guix-publish && systemctl enable guix-publish
12820 If your host distro uses the Upstart init system:
12823 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
12824 # start guix-publish
12828 Otherwise, proceed similarly with your distro's init system.
12831 @node Invoking guix challenge
12832 @section Invoking @command{guix challenge}
12834 @cindex reproducible builds
12835 @cindex verifiable builds
12836 @cindex @command{guix challenge}
12838 Do the binaries provided by this server really correspond to the source
12839 code it claims to build? Is a package build process deterministic?
12840 These are the questions the @command{guix challenge} command attempts to
12843 The former is obviously an important question: Before using a substitute
12844 server (@pxref{Substitutes}), one had better @emph{verify} that it
12845 provides the right binaries, and thus @emph{challenge} it. The latter
12846 is what enables the former: If package builds are deterministic, then
12847 independent builds of the package should yield the exact same result,
12848 bit for bit; if a server provides a binary different from the one
12849 obtained locally, it may be either corrupt or malicious.
12851 We know that the hash that shows up in @file{/gnu/store} file names is
12852 the hash of all the inputs of the process that built the file or
12853 directory---compilers, libraries, build scripts,
12854 etc. (@pxref{Introduction}). Assuming deterministic build processes,
12855 one store file name should map to exactly one build output.
12856 @command{guix challenge} checks whether there is, indeed, a single
12857 mapping by comparing the build outputs of several independent builds of
12858 any given store item.
12860 The command output looks like this:
12863 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
12864 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
12865 updating list of substitutes from 'https://guix.example.org'... 100.0%
12866 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
12867 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
12868 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
12869 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
12871 /lib/libcrypto.so.1.1
12874 /gnu/store/@dots{}-git-2.5.0 contents differ:
12875 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
12876 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
12877 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
12879 /libexec/git-core/git-fsck
12881 /gnu/store/@dots{}-pius-2.1.1 contents differ:
12882 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
12883 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
12884 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
12886 /share/man/man1/pius.1.gz
12890 6,406 store items were analyzed:
12891 - 4,749 (74.1%) were identical
12892 - 525 (8.2%) differed
12893 - 1,132 (17.7%) were inconclusive
12897 In this example, @command{guix challenge} first scans the store to
12898 determine the set of locally-built derivations---as opposed to store
12899 items that were downloaded from a substitute server---and then queries
12900 all the substitute servers. It then reports those store items for which
12901 the servers obtained a result different from the local build.
12903 @cindex non-determinism, in package builds
12904 As an example, @code{guix.example.org} always gets a different answer.
12905 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
12906 case of Git. This might indicate that the build process of Git is
12907 non-deterministic, meaning that its output varies as a function of
12908 various things that Guix does not fully control, in spite of building
12909 packages in isolated environments (@pxref{Features}). Most common
12910 sources of non-determinism include the addition of timestamps in build
12911 results, the inclusion of random numbers, and directory listings sorted
12912 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
12915 To find out what is wrong with this Git binary, the easiest approach is
12919 guix challenge git \
12920 --diff=diffoscope \
12921 --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
12924 This automatically invokes @command{diffoscope}, which displays detailed
12925 information about files that differ.
12927 Alternatively, we can do something along these lines (@pxref{Invoking guix
12931 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-git-2.5.0 \
12932 | lzip -d | guix archive -x /tmp/git
12933 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
12936 This command shows the difference between the files resulting from the
12937 local build, and the files resulting from the build on
12938 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
12939 diffutils, Comparing and Merging Files}). The @command{diff} command
12940 works great for text files. When binary files differ, a better option
12941 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
12942 visualize differences for all kinds of files.
12944 Once you have done that work, you can tell whether the differences are due
12945 to a non-deterministic build process or to a malicious server. We try
12946 hard to remove sources of non-determinism in packages to make it easier
12947 to verify substitutes, but of course, this is a process that
12948 involves not just Guix, but a large part of the free software community.
12949 In the meantime, @command{guix challenge} is one tool to help address
12952 If you are writing packages for Guix, you are encouraged to check
12953 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
12954 same build result as you did with:
12957 $ guix challenge @var{package}
12961 where @var{package} is a package specification such as
12962 @code{guile@@2.0} or @code{glibc:debug}.
12964 The general syntax is:
12967 guix challenge @var{options} [@var{packages}@dots{}]
12970 When a difference is found between the hash of a locally-built item and
12971 that of a server-provided substitute, or among substitutes provided by
12972 different servers, the command displays it as in the example above and
12973 its exit code is 2 (other non-zero exit codes denote other kinds of
12976 The one option that matters is:
12980 @item --substitute-urls=@var{urls}
12981 Consider @var{urls} the whitespace-separated list of substitute source
12982 URLs to compare to.
12984 @item --diff=@var{mode}
12985 Upon mismatches, show differences according to @var{mode}, one of:
12988 @item @code{simple} (the default)
12989 Show the list of files that differ.
12991 @item @code{diffoscope}
12992 @itemx @var{command}
12993 Invoke @uref{https://diffoscope.org/, Diffoscope}, passing it
12994 two directories whose contents do not match.
12996 When @var{command} is an absolute file name, run @var{command} instead
13000 Do not show further details about the differences.
13003 Thus, unless @option{--diff=none} is passed, @command{guix challenge}
13004 downloads the store items from the given substitute servers so that it
13009 Show details about matches (identical contents) in addition to
13010 information about mismatches.
13014 @node Invoking guix copy
13015 @section Invoking @command{guix copy}
13017 @cindex copy, of store items, over SSH
13018 @cindex SSH, copy of store items
13019 @cindex sharing store items across machines
13020 @cindex transferring store items across machines
13021 The @command{guix copy} command copies items from the store of one
13022 machine to that of another machine over a secure shell (SSH)
13023 connection@footnote{This command is available only when Guile-SSH was
13024 found. @xref{Requirements}, for details.}. For example, the following
13025 command copies the @code{coreutils} package, the user's profile, and all
13026 their dependencies over to @var{host}, logged in as @var{user}:
13029 guix copy --to=@var{user}@@@var{host} \
13030 coreutils $(readlink -f ~/.guix-profile)
13033 If some of the items to be copied are already present on @var{host},
13034 they are not actually sent.
13036 The command below retrieves @code{libreoffice} and @code{gimp} from
13037 @var{host}, assuming they are available there:
13040 guix copy --from=@var{host} libreoffice gimp
13043 The SSH connection is established using the Guile-SSH client, which is
13044 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
13045 @file{~/.ssh/config}, and uses the SSH agent for authentication.
13047 The key used to sign items that are sent must be accepted by the remote
13048 machine. Likewise, the key used by the remote machine to sign items you
13049 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
13050 own daemon. @xref{Invoking guix archive}, for more information about
13051 store item authentication.
13053 The general syntax is:
13056 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
13059 You must always specify one of the following options:
13062 @item --to=@var{spec}
13063 @itemx --from=@var{spec}
13064 Specify the host to send to or receive from. @var{spec} must be an SSH
13065 spec such as @code{example.org}, @code{charlie@@example.org}, or
13066 @code{charlie@@example.org:2222}.
13069 The @var{items} can be either package names, such as @code{gimp}, or
13070 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
13072 When specifying the name of a package to send, it is first built if
13073 needed, unless @option{--dry-run} was specified. Common build options
13074 are supported (@pxref{Common Build Options}).
13077 @node Invoking guix container
13078 @section Invoking @command{guix container}
13080 @cindex @command{guix container}
13082 As of version @value{VERSION}, this tool is experimental. The interface
13083 is subject to radical change in the future.
13086 The purpose of @command{guix container} is to manipulate processes
13087 running within an isolated environment, commonly known as a
13088 ``container'', typically created by the @command{guix environment}
13089 (@pxref{Invoking guix environment}) and @command{guix system container}
13090 (@pxref{Invoking guix system}) commands.
13092 The general syntax is:
13095 guix container @var{action} @var{options}@dots{}
13098 @var{action} specifies the operation to perform with a container, and
13099 @var{options} specifies the context-specific arguments for the action.
13101 The following actions are available:
13105 Execute a command within the context of a running container.
13110 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
13113 @var{pid} specifies the process ID of the running container.
13114 @var{program} specifies an executable file name within the root file
13115 system of the container. @var{arguments} are the additional options that
13116 will be passed to @var{program}.
13118 The following command launches an interactive login shell inside a
13119 Guix system container, started by @command{guix system container}, and whose
13120 process ID is 9001:
13123 guix container exec 9001 /run/current-system/profile/bin/bash --login
13126 Note that the @var{pid} cannot be the parent process of a container. It
13127 must be PID 1 of the container or one of its child processes.
13131 @node Invoking guix weather
13132 @section Invoking @command{guix weather}
13134 Occasionally you're grumpy because substitutes are lacking and you end
13135 up building packages by yourself (@pxref{Substitutes}). The
13136 @command{guix weather} command reports on substitute availability on the
13137 specified servers so you can have an idea of whether you'll be grumpy
13138 today. It can sometimes be useful info as a user, but it is primarily
13139 useful to people running @command{guix publish} (@pxref{Invoking guix
13142 @cindex statistics, for substitutes
13143 @cindex availability of substitutes
13144 @cindex substitute availability
13145 @cindex weather, substitute availability
13146 Here's a sample run:
13149 $ guix weather --substitute-urls=https://guix.example.org
13150 computing 5,872 package derivations for x86_64-linux...
13151 looking for 6,128 store items on https://guix.example.org..
13152 updating list of substitutes from 'https://guix.example.org'... 100.0%
13153 https://guix.example.org
13154 43.4% substitutes available (2,658 out of 6,128)
13155 7,032.5 MiB of nars (compressed)
13156 19,824.2 MiB on disk (uncompressed)
13157 0.030 seconds per request (182.9 seconds in total)
13158 33.5 requests per second
13160 9.8% (342 out of 3,470) of the missing items are queued
13162 x86_64-linux: 518 (59.7%)
13163 i686-linux: 221 (25.5%)
13164 aarch64-linux: 128 (14.8%)
13165 build rate: 23.41 builds per hour
13166 x86_64-linux: 11.16 builds per hour
13167 i686-linux: 6.03 builds per hour
13168 aarch64-linux: 6.41 builds per hour
13171 @cindex continuous integration, statistics
13172 As you can see, it reports the fraction of all the packages for which
13173 substitutes are available on the server---regardless of whether
13174 substitutes are enabled, and regardless of whether this server's signing
13175 key is authorized. It also reports the size of the compressed archives
13176 (``nars'') provided by the server, the size the corresponding store
13177 items occupy in the store (assuming deduplication is turned off), and
13178 the server's throughput. The second part gives continuous integration
13179 (CI) statistics, if the server supports it. In addition, using the
13180 @option{--coverage} option, @command{guix weather} can list ``important''
13181 package substitutes missing on the server (see below).
13183 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
13184 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
13185 challenge}, it ignores signatures on those substitutes, which is
13186 innocuous since the command only gathers statistics and cannot install
13189 The general syntax is:
13192 guix weather @var{options}@dots{} [@var{packages}@dots{}]
13195 When @var{packages} is omitted, @command{guix weather} checks the availability
13196 of substitutes for @emph{all} the packages, or for those specified with
13197 @option{--manifest}; otherwise it only considers the specified packages. It
13198 is also possible to query specific system types with @option{--system}.
13199 @command{guix weather} exits with a non-zero code when the fraction of
13200 available substitutes is below 100%.
13202 The available options are listed below.
13205 @item --substitute-urls=@var{urls}
13206 @var{urls} is the space-separated list of substitute server URLs to
13207 query. When this option is omitted, the default set of substitute
13208 servers is queried.
13210 @item --system=@var{system}
13211 @itemx -s @var{system}
13212 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
13213 option can be repeated, in which case @command{guix weather} will query
13214 substitutes for several system types.
13216 @item --manifest=@var{file}
13217 Instead of querying substitutes for all the packages, only ask for those
13218 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
13219 with the @code{-m} option of @command{guix package} (@pxref{Invoking
13222 This option can be repeated several times, in which case the manifests
13225 @item --coverage[=@var{count}]
13226 @itemx -c [@var{count}]
13227 Report on substitute coverage for packages: list packages with at least
13228 @var{count} dependents (zero by default) for which substitutes are
13229 unavailable. Dependent packages themselves are not listed: if @var{b} depends
13230 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
13231 @var{b} usually lacks substitutes as well. The result looks like this:
13234 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
13235 computing 8,983 package derivations for x86_64-linux...
13236 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
13237 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
13238 @value{SUBSTITUTE-URL}
13239 64.7% substitutes available (6,047 out of 9,343)
13241 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
13242 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
13243 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
13244 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
13248 What this example shows is that @code{kcoreaddons} and presumably the 58
13249 packages that depend on it have no substitutes at
13250 @code{@value{SUBSTITUTE-SERVER}}; likewise for @code{qgpgme} and the 46
13251 packages that depend on it.
13253 If you are a Guix developer, or if you are taking care of this build farm,
13254 you'll probably want to have a closer look at these packages: they may simply
13257 @item --display-missing
13258 Display the list of store items for which substitutes are missing.
13261 @node Invoking guix processes
13262 @section Invoking @command{guix processes}
13264 The @command{guix processes} command can be useful to developers and system
13265 administrators, especially on multi-user machines and on build farms: it lists
13266 the current sessions (connections to the daemon), as well as information about
13267 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
13268 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
13269 listed.}. Here's an example of the information it returns:
13272 $ sudo guix processes
13275 ClientCommand: guix environment --ad-hoc python
13279 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
13283 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
13284 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
13285 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
13286 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
13288 ChildCommand: guix offload x86_64-linux 7200 1 28800
13290 ChildCommand: guix offload x86_64-linux 7200 1 28800
13292 ChildCommand: guix offload x86_64-linux 7200 1 28800
13295 In this example we see that @command{guix-daemon} has three clients:
13296 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
13297 integration tool; their process identifier (PID) is given by the
13298 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
13299 @command{guix-daemon} sub-process of this particular session.
13301 The @code{LockHeld} fields show which store items are currently locked
13302 by this session, which corresponds to store items being built or
13303 substituted (the @code{LockHeld} field is not displayed when
13304 @command{guix processes} is not running as root). Last, by looking at
13305 the @code{ChildPID} and @code{ChildCommand} fields, we understand that
13306 these three builds are being offloaded (@pxref{Daemon Offload Setup}).
13308 The output is in Recutils format so we can use the handy @command{recsel}
13309 command to select sessions of interest (@pxref{Selection Expressions,,,
13310 recutils, GNU recutils manual}). As an example, the command shows the command
13311 line and PID of the client that triggered the build of a Perl package:
13314 $ sudo guix processes | \
13315 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
13317 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
13320 Additional options are listed below.
13323 @item --format=@var{format}
13324 @itemx -f @var{format}
13325 Produce output in the specified @var{format}, one of:
13329 The default option. It outputs a set of Session recutils records
13330 that include each @code{ChildProcess} as a field.
13333 Normalize the output records into record sets (@pxref{Record Sets,,,
13334 recutils, GNU recutils manual}). Normalizing into record sets allows
13335 joins across record types. The example below lists the PID of each
13336 @code{ChildProcess} and the associated PID for @code{Session} that
13337 spawned the @code{ChildProcess} where the @code{Session} was started
13338 using @command{guix build}.
13341 $ guix processes --format=normalized | \
13345 -p Session.PID,PID \
13346 -e 'Session.ClientCommand ~ "guix build"'
13359 @node System Configuration
13360 @chapter System Configuration
13362 @cindex system configuration
13363 Guix System supports a consistent whole-system configuration
13364 mechanism. By that we mean that all aspects of the global system
13365 configuration---such as the available system services, timezone and
13366 locale settings, user accounts---are declared in a single place. Such
13367 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
13369 One of the advantages of putting all the system configuration under the
13370 control of Guix is that it supports transactional system upgrades, and
13371 makes it possible to roll back to a previous system instantiation,
13372 should something go wrong with the new one (@pxref{Features}). Another
13373 advantage is that it makes it easy to replicate the exact same configuration
13374 across different machines, or at different points in time, without
13375 having to resort to additional administration tools layered on top of
13376 the own tools of the system.
13377 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
13379 This section describes this mechanism. First we focus on the system
13380 administrator's viewpoint---explaining how the system is configured and
13381 instantiated. Then we show how this mechanism can be extended, for
13382 instance to support new system services.
13385 * Using the Configuration System:: Customizing your GNU system.
13386 * operating-system Reference:: Detail of operating-system declarations.
13387 * File Systems:: Configuring file system mounts.
13388 * Mapped Devices:: Block device extra processing.
13389 * User Accounts:: Specifying user accounts.
13390 * Keyboard Layout:: How the system interprets key strokes.
13391 * Locales:: Language and cultural convention settings.
13392 * Services:: Specifying system services.
13393 * Setuid Programs:: Programs running with root privileges.
13394 * X.509 Certificates:: Authenticating HTTPS servers.
13395 * Name Service Switch:: Configuring libc's name service switch.
13396 * Initial RAM Disk:: Linux-Libre bootstrapping.
13397 * Bootloader Configuration:: Configuring the boot loader.
13398 * Invoking guix system:: Instantiating a system configuration.
13399 * Invoking guix deploy:: Deploying a system configuration to a remote host.
13400 * Running Guix in a VM:: How to run Guix System in a virtual machine.
13401 * Defining Services:: Adding new service definitions.
13404 @node Using the Configuration System
13405 @section Using the Configuration System
13407 The operating system is configured by providing an
13408 @code{operating-system} declaration in a file that can then be passed to
13409 the @command{guix system} command (@pxref{Invoking guix system}). A
13410 simple setup, with the default system services, the default Linux-Libre
13411 kernel, initial RAM disk, and boot loader looks like this:
13413 @findex operating-system
13415 @include os-config-bare-bones.texi
13418 This example should be self-describing. Some of the fields defined
13419 above, such as @code{host-name} and @code{bootloader}, are mandatory.
13420 Others, such as @code{packages} and @code{services}, can be omitted, in
13421 which case they get a default value.
13423 Below we discuss the effect of some of the most important fields
13424 (@pxref{operating-system Reference}, for details about all the available
13425 fields), and how to @dfn{instantiate} the operating system using
13426 @command{guix system}.
13428 @unnumberedsubsec Bootloader
13430 @cindex legacy boot, on Intel machines
13431 @cindex BIOS boot, on Intel machines
13434 The @code{bootloader} field describes the method that will be used to boot
13435 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
13436 mode, as in the example above. However, more recent machines rely instead on
13437 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
13438 the @code{bootloader} field should contain something along these lines:
13441 (bootloader-configuration
13442 (bootloader grub-efi-bootloader)
13443 (target "/boot/efi"))
13446 @xref{Bootloader Configuration}, for more information on the available
13447 configuration options.
13449 @unnumberedsubsec Globally-Visible Packages
13451 @vindex %base-packages
13452 The @code{packages} field lists packages that will be globally visible
13453 on the system, for all user accounts---i.e., in every user's @env{PATH}
13454 environment variable---in addition to the per-user profiles
13455 (@pxref{Invoking guix package}). The @code{%base-packages} variable
13456 provides all the tools one would expect for basic user and administrator
13457 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
13458 the GNU Zile lightweight text editor, @command{find}, @command{grep},
13459 etc. The example above adds GNU@tie{}Screen to those,
13460 taken from the @code{(gnu packages screen)}
13461 module (@pxref{Package Modules}). The
13462 @code{(list package output)} syntax can be used to add a specific output
13466 (use-modules (gnu packages))
13467 (use-modules (gnu packages dns))
13471 (packages (cons (list bind "utils")
13475 @findex specification->package
13476 Referring to packages by variable name, like @code{bind} above, has
13477 the advantage of being unambiguous; it also allows typos and such to be
13478 diagnosed right away as ``unbound variables''. The downside is that one
13479 needs to know which module defines which package, and to augment the
13480 @code{use-package-modules} line accordingly. To avoid that, one can use
13481 the @code{specification->package} procedure of the @code{(gnu packages)}
13482 module, which returns the best package for a given name or name and
13486 (use-modules (gnu packages))
13490 (packages (append (map specification->package
13491 '("tcpdump" "htop" "gnupg@@2.0"))
13495 @unnumberedsubsec System Services
13498 @vindex %base-services
13499 The @code{services} field lists @dfn{system services} to be made
13500 available when the system starts (@pxref{Services}).
13501 The @code{operating-system} declaration above specifies that, in
13502 addition to the basic services, we want the OpenSSH secure shell
13503 daemon listening on port 2222 (@pxref{Networking Services,
13504 @code{openssh-service-type}}). Under the hood,
13505 @code{openssh-service-type} arranges so that @command{sshd} is started with the
13506 right command-line options, possibly with supporting configuration files
13507 generated as needed (@pxref{Defining Services}).
13509 @cindex customization, of services
13510 @findex modify-services
13511 Occasionally, instead of using the base services as is, you will want to
13512 customize them. To do this, use @code{modify-services} (@pxref{Service
13513 Reference, @code{modify-services}}) to modify the list.
13515 For example, suppose you want to modify @code{guix-daemon} and Mingetty
13516 (the console log-in) in the @code{%base-services} list (@pxref{Base
13517 Services, @code{%base-services}}). To do that, you can write the
13518 following in your operating system declaration:
13521 (define %my-services
13522 ;; My very own list of services.
13523 (modify-services %base-services
13524 (guix-service-type config =>
13525 (guix-configuration
13527 ;; Fetch substitutes from example.org.
13529 (list "https://example.org/guix"
13530 "https://ci.guix.gnu.org"))))
13531 (mingetty-service-type config =>
13532 (mingetty-configuration
13534 ;; Automatially log in as "guest".
13535 (auto-login "guest")))))
13539 (services %my-services))
13542 This changes the configuration---i.e., the service parameters---of the
13543 @code{guix-service-type} instance, and that of all the
13544 @code{mingetty-service-type} instances in the @code{%base-services} list.
13545 Observe how this is accomplished: first, we arrange for the original
13546 configuration to be bound to the identifier @code{config} in the
13547 @var{body}, and then we write the @var{body} so that it evaluates to the
13548 desired configuration. In particular, notice how we use @code{inherit}
13549 to create a new configuration which has the same values as the old
13550 configuration, but with a few modifications.
13552 @cindex encrypted disk
13553 The configuration for a typical ``desktop'' usage, with an encrypted
13554 root partition, the X11 display
13555 server, GNOME and Xfce (users can choose which of these desktop
13556 environments to use at the log-in screen by pressing @kbd{F1}), network
13557 management, power management, and more, would look like this:
13560 @include os-config-desktop.texi
13563 A graphical system with a choice of lightweight window managers
13564 instead of full-blown desktop environments would look like this:
13567 @include os-config-lightweight-desktop.texi
13570 This example refers to the @file{/boot/efi} file system by its UUID,
13571 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
13572 as returned by the @command{blkid} command.
13574 @xref{Desktop Services}, for the exact list of services provided by
13575 @code{%desktop-services}. @xref{X.509 Certificates}, for background
13576 information about the @code{nss-certs} package that is used here.
13578 Again, @code{%desktop-services} is just a list of service objects. If
13579 you want to remove services from there, you can do so using the
13580 procedures for list filtering (@pxref{SRFI-1 Filtering and
13581 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
13582 following expression returns a list that contains all the services in
13583 @code{%desktop-services} minus the Avahi service:
13586 (remove (lambda (service)
13587 (eq? (service-kind service) avahi-service-type))
13591 Alternatively, the @code{modify-services} macro can be used:
13594 (modify-services %desktop-services
13595 (delete avahi-service-type))
13599 @unnumberedsubsec Instantiating the System
13601 Assuming the @code{operating-system} declaration
13602 is stored in the @file{my-system-config.scm}
13603 file, the @command{guix system reconfigure my-system-config.scm} command
13604 instantiates that configuration, and makes it the default GRUB boot
13605 entry (@pxref{Invoking guix system}).
13607 The normal way to change the system configuration is by updating this
13608 file and re-running @command{guix system reconfigure}. One should never
13609 have to touch files in @file{/etc} or to run commands that modify the
13610 system state such as @command{useradd} or @command{grub-install}. In
13611 fact, you must avoid that since that would not only void your warranty
13612 but also prevent you from rolling back to previous versions of your
13613 system, should you ever need to.
13615 @cindex roll-back, of the operating system
13616 Speaking of roll-back, each time you run @command{guix system
13617 reconfigure}, a new @dfn{generation} of the system is created---without
13618 modifying or deleting previous generations. Old system generations get
13619 an entry in the bootloader boot menu, allowing you to boot them in case
13620 something went wrong with the latest generation. Reassuring, no? The
13621 @command{guix system list-generations} command lists the system
13622 generations available on disk. It is also possible to roll back the
13623 system via the commands @command{guix system roll-back} and
13624 @command{guix system switch-generation}.
13626 Although the @command{guix system reconfigure} command will not modify
13627 previous generations, you must take care when the current generation is not
13628 the latest (e.g., after invoking @command{guix system roll-back}), since
13629 the operation might overwrite a later generation (@pxref{Invoking guix
13632 @unnumberedsubsec The Programming Interface
13634 At the Scheme level, the bulk of an @code{operating-system} declaration
13635 is instantiated with the following monadic procedure (@pxref{The Store
13638 @deffn {Monadic Procedure} operating-system-derivation os
13639 Return a derivation that builds @var{os}, an @code{operating-system}
13640 object (@pxref{Derivations}).
13642 The output of the derivation is a single directory that refers to all
13643 the packages, configuration files, and other supporting files needed to
13644 instantiate @var{os}.
13647 This procedure is provided by the @code{(gnu system)} module. Along
13648 with @code{(gnu services)} (@pxref{Services}), this module contains the
13649 guts of Guix System. Make sure to visit it!
13652 @node operating-system Reference
13653 @section @code{operating-system} Reference
13655 This section summarizes all the options available in
13656 @code{operating-system} declarations (@pxref{Using the Configuration
13659 @deftp {Data Type} operating-system
13660 This is the data type representing an operating system configuration.
13661 By that, we mean all the global system configuration, not per-user
13662 configuration (@pxref{Using the Configuration System}).
13665 @item @code{kernel} (default: @code{linux-libre})
13666 The package object of the operating system kernel to
13667 use@footnote{Currently only the Linux-libre kernel is fully supported.
13668 Using GNU@tie{}mach with the GNU@tie{}Hurd is experimental and only
13669 available when building a virtual machine disk image.}.
13672 @item @code{hurd} (default: @code{#f})
13673 The package object of the Hurd to be started by the kernel. When this
13674 field is set, produce a GNU/Hurd operating system. In that case,
13675 @code{kernel} must also be set to the @code{gnumach} package---the
13676 microkernel the Hurd runs on.
13679 This feature is experimental and only supported for disk images.
13682 @item @code{kernel-loadable-modules} (default: '())
13683 A list of objects (usually packages) to collect loadable kernel modules
13684 from--e.g. @code{(list ddcci-driver-linux)}.
13686 @item @code{kernel-arguments} (default: @code{%default-kernel-arguments})
13687 List of strings or gexps representing additional arguments to pass on
13688 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
13690 @item @code{bootloader}
13691 The system bootloader configuration object. @xref{Bootloader Configuration}.
13694 This is the label (a string) as it appears in the bootloader's menu entry.
13695 The default label includes the kernel name and version.
13697 @item @code{keyboard-layout} (default: @code{#f})
13698 This field specifies the keyboard layout to use in the console. It can be
13699 either @code{#f}, in which case the default keyboard layout is used (usually
13700 US English), or a @code{<keyboard-layout>} record. @xref{Keyboard Layout},
13701 for more information.
13703 This keyboard layout is in effect as soon as the kernel has booted. For
13704 instance, it is the keyboard layout in effect when you type a passphrase if
13705 your root file system is on a @code{luks-device-mapping} mapped device
13706 (@pxref{Mapped Devices}).
13709 This does @emph{not} specify the keyboard layout used by the bootloader, nor
13710 that used by the graphical display server. @xref{Bootloader Configuration},
13711 for information on how to specify the bootloader's keyboard layout. @xref{X
13712 Window}, for information on how to specify the keyboard layout used by the X
13716 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
13718 @cindex initial RAM disk
13719 The list of Linux kernel modules that need to be available in the
13720 initial RAM disk. @xref{Initial RAM Disk}.
13722 @item @code{initrd} (default: @code{base-initrd})
13723 A procedure that returns an initial RAM disk for the Linux
13724 kernel. This field is provided to support low-level customization and
13725 should rarely be needed for casual use. @xref{Initial RAM Disk}.
13727 @item @code{firmware} (default: @code{%base-firmware})
13729 List of firmware packages loadable by the operating system kernel.
13731 The default includes firmware needed for Atheros- and Broadcom-based
13732 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
13733 respectively). @xref{Hardware Considerations}, for more info on
13734 supported hardware.
13736 @item @code{host-name}
13739 @item @code{hosts-file}
13741 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
13742 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
13743 Reference Manual}). The default is a file with entries for
13744 @code{localhost} and @var{host-name}.
13746 @item @code{mapped-devices} (default: @code{'()})
13747 A list of mapped devices. @xref{Mapped Devices}.
13749 @item @code{file-systems}
13750 A list of file systems. @xref{File Systems}.
13752 @cindex swap devices
13754 @item @code{swap-devices} (default: @code{'()})
13755 A list of UUIDs, file system labels, or strings identifying devices or
13756 files to be used for ``swap
13757 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
13758 Manual}). Here are some examples:
13761 @item (list (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb"))
13762 Use the swap partition with the given UUID@. You can learn the UUID of a
13763 Linux swap partition by running @command{swaplabel @var{device}}, where
13764 @var{device} is the @file{/dev} file name of that partition.
13766 @item (list (file-system-label "swap"))
13767 Use the partition with label @code{swap}. Again, the
13768 @command{swaplabel} command allows you to view and change the label of a
13769 Linux swap partition.
13771 @item (list "/swapfile")
13772 Use the file @file{/swapfile} as swap space.
13774 @item (list "/dev/sda3" "/dev/sdb2")
13775 Use the @file{/dev/sda3} and @file{/dev/sdb2} partitions as swap space.
13776 We recommend referring to swap devices by UUIDs or labels as shown above
13780 It is possible to specify a swap file in a file system on a mapped
13781 device (under @file{/dev/mapper}), provided that the necessary device
13782 mapping and file system are also specified. @xref{Mapped Devices} and
13783 @ref{File Systems}.
13785 @item @code{users} (default: @code{%base-user-accounts})
13786 @itemx @code{groups} (default: @code{%base-groups})
13787 List of user accounts and groups. @xref{User Accounts}.
13789 If the @code{users} list lacks a user account with UID@tie{}0, a
13790 ``root'' account with UID@tie{}0 is automatically added.
13792 @item @code{skeletons} (default: @code{(default-skeletons)})
13793 A list of target file name/file-like object tuples (@pxref{G-Expressions,
13794 file-like objects}). These are the skeleton files that will be added to
13795 the home directory of newly-created user accounts.
13797 For instance, a valid value may look like this:
13800 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
13801 (".guile" ,(plain-file "guile"
13802 "(use-modules (ice-9 readline))
13803 (activate-readline)")))
13806 @item @code{issue} (default: @code{%default-issue})
13807 A string denoting the contents of the @file{/etc/issue} file, which is
13808 displayed when users log in on a text console.
13810 @item @code{packages} (default: @code{%base-packages})
13811 A list of packages to be installed in the global profile, which is accessible
13812 at @file{/run/current-system/profile}. Each element is either a package
13813 variable or a package/output tuple. Here's a simple example of both:
13816 (cons* git ; the default "out" output
13817 (list git "send-email") ; another output of git
13818 %base-packages) ; the default set
13821 The default set includes core utilities and it is good practice to
13822 install non-core utilities in user profiles (@pxref{Invoking guix
13825 @item @code{timezone}
13826 A timezone identifying string---e.g., @code{"Europe/Paris"}.
13828 You can run the @command{tzselect} command to find out which timezone
13829 string corresponds to your region. Choosing an invalid timezone name
13830 causes @command{guix system} to fail.
13832 @item @code{locale} (default: @code{"en_US.utf8"})
13833 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
13834 Library Reference Manual}). @xref{Locales}, for more information.
13836 @item @code{locale-definitions} (default: @code{%default-locale-definitions})
13837 The list of locale definitions to be compiled and that may be used at
13838 run time. @xref{Locales}.
13840 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
13841 The list of GNU@tie{}libc packages whose locale data and tools are used
13842 to build the locale definitions. @xref{Locales}, for compatibility
13843 considerations that justify this option.
13845 @item @code{name-service-switch} (default: @code{%default-nss})
13846 Configuration of the libc name service switch (NSS)---a
13847 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
13850 @item @code{services} (default: @code{%base-services})
13851 A list of service objects denoting system services. @xref{Services}.
13853 @cindex essential services
13854 @item @code{essential-services} (default: ...)
13855 The list of ``essential services''---i.e., things like instances of
13856 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
13857 Reference}), which are derived from the operating system definition itself.
13858 As a user you should @emph{never} need to touch this field.
13860 @item @code{pam-services} (default: @code{(base-pam-services)})
13862 @cindex pluggable authentication modules
13863 Linux @dfn{pluggable authentication module} (PAM) services.
13864 @c FIXME: Add xref to PAM services section.
13866 @item @code{setuid-programs} (default: @code{%setuid-programs})
13867 List of string-valued G-expressions denoting setuid programs.
13868 @xref{Setuid Programs}.
13870 @item @code{sudoers-file} (default: @code{%sudoers-specification})
13871 @cindex sudoers file
13872 The contents of the @file{/etc/sudoers} file as a file-like object
13873 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
13875 This file specifies which users can use the @command{sudo} command, what
13876 they are allowed to do, and what privileges they may gain. The default
13877 is that only @code{root} and members of the @code{wheel} group may use
13882 @deffn {Scheme Syntax} this-operating-system
13883 When used in the @emph{lexical scope} of an operating system field definition,
13884 this identifier resolves to the operating system being defined.
13886 The example below shows how to refer to the operating system being defined in
13887 the definition of the @code{label} field:
13890 (use-modules (gnu) (guix))
13894 (label (package-full-name
13895 (operating-system-kernel this-operating-system))))
13898 It is an error to refer to @code{this-operating-system} outside an operating
13905 @section File Systems
13907 The list of file systems to be mounted is specified in the
13908 @code{file-systems} field of the operating system declaration
13909 (@pxref{Using the Configuration System}). Each file system is declared
13910 using the @code{file-system} form, like this:
13914 (mount-point "/home")
13915 (device "/dev/sda3")
13919 As usual, some of the fields are mandatory---those shown in the example
13920 above---while others can be omitted. These are described below.
13922 @deftp {Data Type} file-system
13923 Objects of this type represent file systems to be mounted. They
13924 contain the following members:
13928 This is a string specifying the type of the file system---e.g.,
13931 @item @code{mount-point}
13932 This designates the place where the file system is to be mounted.
13934 @item @code{device}
13935 This names the ``source'' of the file system. It can be one of three
13936 things: a file system label, a file system UUID, or the name of a
13937 @file{/dev} node. Labels and UUIDs offer a way to refer to file
13938 systems without having to hard-code their actual device
13939 name@footnote{Note that, while it is tempting to use
13940 @file{/dev/disk/by-uuid} and similar device names to achieve the same
13941 result, this is not recommended: These special device nodes are created
13942 by the udev daemon and may be unavailable at the time the device is
13945 @findex file-system-label
13946 File system labels are created using the @code{file-system-label}
13947 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
13948 plain strings. Here's an example of a file system referred to by its
13949 label, as shown by the @command{e2label} command:
13953 (mount-point "/home")
13955 (device (file-system-label "my-home")))
13959 UUIDs are converted from their string representation (as shown by the
13960 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
13961 @code{uuid} form expects 16-byte UUIDs as defined in
13962 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
13963 form of UUID used by the ext2 family of file systems and others, but it
13964 is different from ``UUIDs'' found in FAT file systems, for instance.},
13969 (mount-point "/home")
13971 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
13974 When the source of a file system is a mapped device (@pxref{Mapped
13975 Devices}), its @code{device} field @emph{must} refer to the mapped
13976 device name---e.g., @file{"/dev/mapper/root-partition"}.
13977 This is required so that
13978 the system knows that mounting the file system depends on having the
13979 corresponding device mapping established.
13981 @item @code{flags} (default: @code{'()})
13982 This is a list of symbols denoting mount flags. Recognized flags
13983 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
13984 access to special files), @code{no-suid} (ignore setuid and setgid
13985 bits), @code{no-atime} (do not update file access times),
13986 @code{strict-atime} (update file access time), @code{lazy-time} (only
13987 update time on the in-memory version of the file inode), and
13988 @code{no-exec} (disallow program execution).
13989 @xref{Mount-Unmount-Remount,,, libc, The GNU C Library Reference
13990 Manual}, for more information on these flags.
13992 @item @code{options} (default: @code{#f})
13993 This is either @code{#f}, or a string denoting mount options passed to
13994 the file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C
13995 Library Reference Manual}, for details and run @command{man 8 mount} for
13996 options for various file systems. Note that the
13997 @code{file-system-options->alist} and @code{alist->file-system-options}
13998 procedures from @code{(gnu system file-systems)} can be used to convert
13999 file system options given as an association list to the string
14000 representation, and vice-versa.
14002 @item @code{mount?} (default: @code{#t})
14003 This value indicates whether to automatically mount the file system when
14004 the system is brought up. When set to @code{#f}, the file system gets
14005 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
14006 is not automatically mounted.
14008 @item @code{needed-for-boot?} (default: @code{#f})
14009 This Boolean value indicates whether the file system is needed when
14010 booting. If that is true, then the file system is mounted when the
14011 initial RAM disk (initrd) is loaded. This is always the case, for
14012 instance, for the root file system.
14014 @item @code{check?} (default: @code{#t})
14015 This Boolean indicates whether the file system needs to be checked for
14016 errors before being mounted.
14018 @item @code{create-mount-point?} (default: @code{#f})
14019 When true, the mount point is created if it does not exist yet.
14021 @item @code{mount-may-fail?} (default: @code{#f})
14022 When true, this indicates that mounting this file system can fail but
14023 that should not be considered an error. This is useful in unusual
14024 cases; an example of this is @code{efivarfs}, a file system that can
14025 only be mounted on EFI/UEFI systems.
14027 @item @code{dependencies} (default: @code{'()})
14028 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
14029 representing file systems that must be mounted or mapped devices that
14030 must be opened before (and unmounted or closed after) this one.
14032 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
14033 a dependency of @file{/sys/fs/cgroup/cpu} and
14034 @file{/sys/fs/cgroup/memory}.
14036 Another example is a file system that depends on a mapped device, for
14037 example for an encrypted partition (@pxref{Mapped Devices}).
14041 @deffn {Scheme Procedure} file-system-label @var{str}
14042 This procedure returns an opaque file system label from @var{str}, a
14046 (file-system-label "home")
14047 @result{} #<file-system-label "home">
14050 File system labels are used to refer to file systems by label rather
14051 than by device name. See above for examples.
14054 The @code{(gnu system file-systems)} exports the following useful
14057 @defvr {Scheme Variable} %base-file-systems
14058 These are essential file systems that are required on normal systems,
14059 such as @code{%pseudo-terminal-file-system} and @code{%immutable-store} (see
14060 below). Operating system declarations should always contain at least
14064 @defvr {Scheme Variable} %pseudo-terminal-file-system
14065 This is the file system to be mounted as @file{/dev/pts}. It supports
14066 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
14067 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
14068 Manual}). Pseudo-terminals are used by terminal emulators such as
14072 @defvr {Scheme Variable} %shared-memory-file-system
14073 This file system is mounted as @file{/dev/shm} and is used to support
14074 memory sharing across processes (@pxref{Memory-mapped I/O,
14075 @code{shm_open},, libc, The GNU C Library Reference Manual}).
14078 @defvr {Scheme Variable} %immutable-store
14079 This file system performs a read-only ``bind mount'' of
14080 @file{/gnu/store}, making it read-only for all the users including
14081 @code{root}. This prevents against accidental modification by software
14082 running as @code{root} or by system administrators.
14084 The daemon itself is still able to write to the store: it remounts it
14085 read-write in its own ``name space.''
14088 @defvr {Scheme Variable} %binary-format-file-system
14089 The @code{binfmt_misc} file system, which allows handling of arbitrary
14090 executable file types to be delegated to user space. This requires the
14091 @code{binfmt.ko} kernel module to be loaded.
14094 @defvr {Scheme Variable} %fuse-control-file-system
14095 The @code{fusectl} file system, which allows unprivileged users to mount
14096 and unmount user-space FUSE file systems. This requires the
14097 @code{fuse.ko} kernel module to be loaded.
14100 The @code{(gnu system uuid)} module provides tools to deal with file
14101 system ``unique identifiers'' (UUIDs).
14103 @deffn {Scheme Procedure} uuid @var{str} [@var{type}]
14104 Return an opaque UUID (unique identifier) object of the given @var{type}
14105 (a symbol) by parsing @var{str} (a string):
14108 (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")
14109 @result{} #<<uuid> type: dce bv: @dots{}>
14111 (uuid "1234-ABCD" 'fat)
14112 @result{} #<<uuid> type: fat bv: @dots{}>
14115 @var{type} may be one of @code{dce}, @code{iso9660}, @code{fat},
14116 @code{ntfs}, or one of the commonly found synonyms for these.
14118 UUIDs are another way to unambiguously refer to file systems in
14119 operating system configuration. See the examples above.
14123 @node Btrfs file system
14124 @subsection Btrfs file system
14126 The Btrfs has special features, such as subvolumes, that merit being
14127 explained in more details. The following section attempts to cover
14128 basic as well as complex uses of a Btrfs file system with the Guix
14131 In its simplest usage, a Btrfs file system can be described, for
14136 (mount-point "/home")
14138 (device (file-system-label "my-home")))
14141 The example below is more complex, as it makes use of a Btrfs
14142 subvolume, named @code{rootfs}. The parent Btrfs file system is labeled
14143 @code{my-btrfs-pool}, and is located on an encrypted device (hence the
14144 dependency on @code{mapped-devices}):
14148 (device (file-system-label "my-btrfs-pool"))
14151 (options "subvol=rootfs")
14152 (dependencies mapped-devices))
14155 Some bootloaders, for example GRUB, only mount a Btrfs partition at its
14156 top level during the early boot, and rely on their configuration to
14157 refer to the correct subvolume path within that top level. The
14158 bootloaders operating in this way typically produce their configuration
14159 on a running system where the Btrfs partitions are already mounted and
14160 where the subvolume information is readily available. As an example,
14161 @command{grub-mkconfig}, the configuration generator command shipped
14162 with GRUB, reads @file{/proc/self/mountinfo} to determine the top-level
14163 path of a subvolume.
14165 The Guix System produces a bootloader configuration using the operating
14166 system configuration as its sole input; it is therefore necessary to
14167 extract the subvolume name on which @file{/gnu/store} lives (if any)
14168 from that operating system configuration. To better illustrate,
14169 consider a subvolume named 'rootfs' which contains the root file system
14170 data. In such situation, the GRUB bootloader would only see the top
14171 level of the root Btrfs partition, e.g.:
14175 ├── rootfs (subvolume directory)
14176 ├── gnu (normal directory)
14177 ├── store (normal directory)
14181 Thus, the subvolume name must be prepended to the @file{/gnu/store} path
14182 of the kernel, initrd binaries and any other files referred to in the
14183 GRUB configuration that must be found during the early boot.
14185 The next example shows a nested hierarchy of subvolumes and
14190 ├── rootfs (subvolume)
14191 ├── gnu (normal directory)
14192 ├── store (subvolume)
14196 This scenario would work without mounting the 'store' subvolume.
14197 Mounting 'rootfs' is sufficient, since the subvolume name matches its
14198 intended mount point in the file system hierarchy. Alternatively, the
14199 'store' subvolume could be referred to by setting the @code{subvol}
14200 option to either @code{/rootfs/gnu/store} or @code{rootfs/gnu/store}.
14202 Finally, a more contrived example of nested subvolumes:
14206 ├── root-snapshots (subvolume)
14207 ├── root-current (subvolume)
14208 ├── guix-store (subvolume)
14212 Here, the 'guix-store' subvolume doesn't match its intended mount point,
14213 so it is necessary to mount it. The subvolume must be fully specified,
14214 by passing its file name to the @code{subvol} option. To illustrate,
14215 the 'guix-store' subvolume could be mounted on @file{/gnu/store} by using
14216 a file system declaration such as:
14220 (device (file-system-label "btrfs-pool-1"))
14221 (mount-point "/gnu/store")
14223 (options "subvol=root-snapshots/root-current/guix-store,\
14224 compress-force=zstd,space_cache=v2"))
14227 @node Mapped Devices
14228 @section Mapped Devices
14230 @cindex device mapping
14231 @cindex mapped devices
14232 The Linux kernel has a notion of @dfn{device mapping}: a block device,
14233 such as a hard disk partition, can be @dfn{mapped} into another device,
14234 usually in @code{/dev/mapper/},
14235 with additional processing over the data that flows through
14236 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
14237 concept of a ``mapped device'' and that of a file system: both boil down
14238 to @emph{translating} input/output operations made on a file to
14239 operations on its backing store. Thus, the Hurd implements mapped
14240 devices, like file systems, using the generic @dfn{translator} mechanism
14241 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
14242 typical example is encryption device mapping: all writes to the mapped
14243 device are encrypted, and all reads are deciphered, transparently.
14244 Guix extends this notion by considering any device or set of devices that
14245 are @dfn{transformed} in some way to create a new device; for instance,
14246 RAID devices are obtained by @dfn{assembling} several other devices, such
14247 as hard disks or partitions, into a new one that behaves as one partition.
14249 Mapped devices are declared using the @code{mapped-device} form,
14250 defined as follows; for examples, see below.
14252 @deftp {Data Type} mapped-device
14253 Objects of this type represent device mappings that will be made when
14254 the system boots up.
14258 This is either a string specifying the name of the block device to be mapped,
14259 such as @code{"/dev/sda3"}, or a list of such strings when several devices
14260 need to be assembled for creating a new one. In case of LVM this is a
14261 string specifying name of the volume group to be mapped.
14264 This string specifies the name of the resulting mapped device. For
14265 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
14266 specifying @code{"my-partition"} leads to the creation of
14267 the @code{"/dev/mapper/my-partition"} device.
14268 For RAID devices of type @code{raid-device-mapping}, the full device name
14269 such as @code{"/dev/md0"} needs to be given.
14270 LVM logical volumes of type @code{lvm-device-mapping} need to
14271 be specified as @code{"VGNAME-LVNAME"}.
14274 This list of strings specifies names of the resulting mapped devices in case
14275 there are several. The format is identical to @var{target}.
14278 This must be a @code{mapped-device-kind} object, which specifies how
14279 @var{source} is mapped to @var{target}.
14283 @defvr {Scheme Variable} luks-device-mapping
14284 This defines LUKS block device encryption using the @command{cryptsetup}
14285 command from the package with the same name. It relies on the
14286 @code{dm-crypt} Linux kernel module.
14289 @defvr {Scheme Variable} raid-device-mapping
14290 This defines a RAID device, which is assembled using the @code{mdadm}
14291 command from the package with the same name. It requires a Linux kernel
14292 module for the appropriate RAID level to be loaded, such as @code{raid456}
14293 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
14296 @cindex LVM, logical volume manager
14297 @defvr {Scheme Variable} lvm-device-mapping
14298 This defines one or more logical volumes for the Linux
14299 @uref{https://www.sourceware.org/lvm2/, Logical Volume Manager (LVM)}.
14300 The volume group is activated by the @command{vgchange} command from the
14301 @code{lvm2} package.
14304 @cindex disk encryption
14306 The following example specifies a mapping from @file{/dev/sda3} to
14307 @file{/dev/mapper/home} using LUKS---the
14308 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
14309 standard mechanism for disk encryption.
14310 The @file{/dev/mapper/home}
14311 device can then be used as the @code{device} of a @code{file-system}
14312 declaration (@pxref{File Systems}).
14316 (source "/dev/sda3")
14318 (type luks-device-mapping))
14321 Alternatively, to become independent of device numbering, one may obtain
14322 the LUKS UUID (@dfn{unique identifier}) of the source device by a
14326 cryptsetup luksUUID /dev/sda3
14329 and use it as follows:
14333 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
14335 (type luks-device-mapping))
14338 @cindex swap encryption
14339 It is also desirable to encrypt swap space, since swap space may contain
14340 sensitive data. One way to accomplish that is to use a swap file in a
14341 file system on a device mapped via LUKS encryption. In this way, the
14342 swap file is encrypted because the entire device is encrypted.
14343 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
14345 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
14346 may be declared as follows:
14350 (source (list "/dev/sda1" "/dev/sdb1"))
14351 (target "/dev/md0")
14352 (type raid-device-mapping))
14355 The @file{/dev/md0} device can then be used as the @code{device} of a
14356 @code{file-system} declaration (@pxref{File Systems}).
14357 Note that the RAID level need not be given; it is chosen during the
14358 initial creation and formatting of the RAID device and is determined
14359 automatically later.
14361 LVM logical volumes ``alpha'' and ``beta'' from volume group ``vg0'' can
14362 be declared as follows:
14367 (targets (list "vg0-alpha" "vg0-beta"))
14368 (type lvm-device-mapping))
14371 Devices @file{/dev/mapper/vg0-alpha} and @file{/dev/mapper/vg0-beta} can
14372 then be used as the @code{device} of a @code{file-system} declaration
14373 (@pxref{File Systems}).
14375 @node User Accounts
14376 @section User Accounts
14380 @cindex user accounts
14381 User accounts and groups are entirely managed through the
14382 @code{operating-system} declaration. They are specified with the
14383 @code{user-account} and @code{user-group} forms:
14389 (supplementary-groups '("wheel" ;allow use of sudo, etc.
14390 "audio" ;sound card
14391 "video" ;video devices such as webcams
14392 "cdrom")) ;the good ol' CD-ROM
14393 (comment "Bob's sister"))
14396 Here's a user account that uses a different shell and a custom home
14397 directory (the default would be @file{"/home/bob"}):
14403 (comment "Alice's bro")
14404 (shell (file-append zsh "/bin/zsh"))
14405 (home-directory "/home/robert"))
14408 When booting or upon completion of @command{guix system reconfigure},
14409 the system ensures that only the user accounts and groups specified in
14410 the @code{operating-system} declaration exist, and with the specified
14411 properties. Thus, account or group creations or modifications made by
14412 directly invoking commands such as @command{useradd} are lost upon
14413 reconfiguration or reboot. This ensures that the system remains exactly
14416 @deftp {Data Type} user-account
14417 Objects of this type represent user accounts. The following members may
14422 The name of the user account.
14426 This is the name (a string) or identifier (a number) of the user group
14427 this account belongs to.
14429 @item @code{supplementary-groups} (default: @code{'()})
14430 Optionally, this can be defined as a list of group names that this
14431 account belongs to.
14433 @item @code{uid} (default: @code{#f})
14434 This is the user ID for this account (a number), or @code{#f}. In the
14435 latter case, a number is automatically chosen by the system when the
14436 account is created.
14438 @item @code{comment} (default: @code{""})
14439 A comment about the account, such as the account owner's full name.
14441 @item @code{home-directory}
14442 This is the name of the home directory for the account.
14444 @item @code{create-home-directory?} (default: @code{#t})
14445 Indicates whether the home directory of this account should be created
14446 if it does not exist yet.
14448 @item @code{shell} (default: Bash)
14449 This is a G-expression denoting the file name of a program to be used as
14450 the shell (@pxref{G-Expressions}). For example, you would refer to the
14451 Bash executable like this:
14454 (file-append bash "/bin/bash")
14458 ... and to the Zsh executable like that:
14461 (file-append zsh "/bin/zsh")
14464 @item @code{system?} (default: @code{#f})
14465 This Boolean value indicates whether the account is a ``system''
14466 account. System accounts are sometimes treated specially; for instance,
14467 graphical login managers do not list them.
14469 @anchor{user-account-password}
14470 @cindex password, for user accounts
14471 @item @code{password} (default: @code{#f})
14472 You would normally leave this field to @code{#f}, initialize user
14473 passwords as @code{root} with the @command{passwd} command, and then let
14474 users change it with @command{passwd}. Passwords set with
14475 @command{passwd} are of course preserved across reboot and
14478 If you @emph{do} want to set an initial password for an account, then
14479 this field must contain the encrypted password, as a string. You can use the
14480 @code{crypt} procedure for this purpose:
14487 ;; Specify a SHA-512-hashed initial password.
14488 (password (crypt "InitialPassword!" "$6$abc")))
14492 The hash of this initial password will be available in a file in
14493 @file{/gnu/store}, readable by all the users, so this method must be used with
14497 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
14498 more information on password encryption, and @ref{Encryption,,, guile, GNU
14499 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
14505 User group declarations are even simpler:
14508 (user-group (name "students"))
14511 @deftp {Data Type} user-group
14512 This type is for, well, user groups. There are just a few fields:
14516 The name of the group.
14518 @item @code{id} (default: @code{#f})
14519 The group identifier (a number). If @code{#f}, a new number is
14520 automatically allocated when the group is created.
14522 @item @code{system?} (default: @code{#f})
14523 This Boolean value indicates whether the group is a ``system'' group.
14524 System groups have low numerical IDs.
14526 @item @code{password} (default: @code{#f})
14527 What, user groups can have a password? Well, apparently yes. Unless
14528 @code{#f}, this field specifies the password of the group.
14533 For convenience, a variable lists all the basic user groups one may
14536 @defvr {Scheme Variable} %base-groups
14537 This is the list of basic user groups that users and/or packages expect
14538 to be present on the system. This includes groups such as ``root'',
14539 ``wheel'', and ``users'', as well as groups used to control access to
14540 specific devices such as ``audio'', ``disk'', and ``cdrom''.
14543 @defvr {Scheme Variable} %base-user-accounts
14544 This is the list of basic system accounts that programs may expect to
14545 find on a GNU/Linux system, such as the ``nobody'' account.
14547 Note that the ``root'' account is not included here. It is a
14548 special-case and is automatically added whether or not it is specified.
14551 @node Keyboard Layout
14552 @section Keyboard Layout
14554 @cindex keyboard layout
14556 To specify what each key of your keyboard does, you need to tell the operating
14557 system what @dfn{keyboard layout} you want to use. The default, when nothing
14558 is specified, is the US English QWERTY layout for 105-key PC keyboards.
14559 However, German speakers will usually prefer the German QWERTZ layout, French
14560 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
14561 or bépo, and they might even want to further customize the effect of some of
14562 the keys. This section explains how to get that done.
14564 @cindex keyboard layout, definition
14565 There are three components that will want to know about your keyboard layout:
14569 The @emph{bootloader} may want to know what keyboard layout you want to use
14570 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
14571 you want, for instance, to make sure that you can type the passphrase of your
14572 encrypted root partition using the right layout.
14575 The @emph{operating system kernel}, Linux, will need that so that the console
14576 is properly configured (@pxref{operating-system Reference,
14577 @code{keyboard-layout}}).
14580 The @emph{graphical display server}, usually Xorg, also has its own idea of
14581 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
14584 Guix allows you to configure all three separately but, fortunately, it allows
14585 you to share the same keyboard layout for all three components.
14587 @cindex XKB, keyboard layouts
14588 Keyboard layouts are represented by records created by the
14589 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
14590 the X Keyboard extension (XKB), each layout has four attributes: a name (often
14591 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
14592 optional variant name, an optional keyboard model name, and a possibly empty
14593 list of additional options. In most cases the layout name is all you care
14596 @deffn {Scheme Procedure} keyboard-layout @var{name} [@var{variant}] @
14597 [#:model] [#:options '()]
14598 Return a new keyboard layout with the given @var{name} and @var{variant}.
14600 @var{name} must be a string such as @code{"fr"}; @var{variant} must be a
14601 string such as @code{"bepo"} or @code{"nodeadkeys"}. See the
14602 @code{xkeyboard-config} package for valid options.
14605 Here are a few examples:
14608 ;; The German QWERTZ layout. Here we assume a standard
14609 ;; "pc105" keyboard model.
14610 (keyboard-layout "de")
14612 ;; The bépo variant of the French layout.
14613 (keyboard-layout "fr" "bepo")
14615 ;; The Catalan layout.
14616 (keyboard-layout "es" "cat")
14618 ;; Arabic layout with "Alt-Shift" to switch to US layout.
14619 (keyboard-layout "ar,us" #:options '("grp:alt_shift_toggle"))
14621 ;; The Latin American Spanish layout. In addition, the
14622 ;; "Caps Lock" key is used as an additional "Ctrl" key,
14623 ;; and the "Menu" key is used as a "Compose" key to enter
14624 ;; accented letters.
14625 (keyboard-layout "latam"
14626 #:options '("ctrl:nocaps" "compose:menu"))
14628 ;; The Russian layout for a ThinkPad keyboard.
14629 (keyboard-layout "ru" #:model "thinkpad")
14631 ;; The "US international" layout, which is the US layout plus
14632 ;; dead keys to enter accented characters. This is for an
14633 ;; Apple MacBook keyboard.
14634 (keyboard-layout "us" "intl" #:model "macbook78")
14637 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
14638 for a complete list of supported layouts, variants, and models.
14640 @cindex keyboard layout, configuration
14641 Let's say you want your system to use the Turkish keyboard layout throughout
14642 your system---bootloader, console, and Xorg. Here's what your system
14643 configuration would look like:
14645 @findex set-xorg-configuration
14647 ;; Using the Turkish layout for the bootloader, the console,
14652 (keyboard-layout (keyboard-layout "tr")) ;for the console
14653 (bootloader (bootloader-configuration
14654 (bootloader grub-efi-bootloader)
14655 (target "/boot/efi")
14656 (keyboard-layout keyboard-layout))) ;for GRUB
14657 (services (cons (set-xorg-configuration
14658 (xorg-configuration ;for Xorg
14659 (keyboard-layout keyboard-layout)))
14660 %desktop-services)))
14663 In the example above, for GRUB and for Xorg, we just refer to the
14664 @code{keyboard-layout} field defined above, but we could just as well refer to
14665 a different layout. The @code{set-xorg-configuration} procedure communicates
14666 the desired Xorg configuration to the graphical log-in manager, by default
14669 We've discussed how to specify the @emph{default} keyboard layout of your
14670 system when it starts, but you can also adjust it at run time:
14674 If you're using GNOME, its settings panel has a ``Region & Language'' entry
14675 where you can select one or more keyboard layouts.
14678 Under Xorg, the @command{setxkbmap} command (from the same-named package)
14679 allows you to change the current layout. For example, this is how you would
14680 change the layout to US Dvorak:
14683 setxkbmap us dvorak
14687 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
14688 console. However, note that @code{loadkeys} does @emph{not} use the XKB
14689 keyboard layout categorization described above. The command below loads the
14690 French bépo layout:
14701 A @dfn{locale} defines cultural conventions for a particular language
14702 and region of the world (@pxref{Locales,,, libc, The GNU C Library
14703 Reference Manual}). Each locale has a name that typically has the form
14704 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
14705 @code{fr_LU.utf8} designates the locale for the French language, with
14706 cultural conventions from Luxembourg, and using the UTF-8 encoding.
14708 @cindex locale definition
14709 Usually, you will want to specify the default locale for the machine
14710 using the @code{locale} field of the @code{operating-system} declaration
14711 (@pxref{operating-system Reference, @code{locale}}).
14713 The selected locale is automatically added to the @dfn{locale
14714 definitions} known to the system if needed, with its codeset inferred
14715 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
14716 @code{UTF-8} codeset. Additional locale definitions can be specified in
14717 the @code{locale-definitions} slot of @code{operating-system}---this is
14718 useful, for instance, if the codeset could not be inferred from the
14719 locale name. The default set of locale definitions includes some widely
14720 used locales, but not all the available locales, in order to save space.
14722 For instance, to add the North Frisian locale for Germany, the value of
14726 (cons (locale-definition
14727 (name "fy_DE.utf8") (source "fy_DE"))
14728 %default-locale-definitions)
14731 Likewise, to save space, one might want @code{locale-definitions} to
14732 list only the locales that are actually used, as in:
14735 (list (locale-definition
14736 (name "ja_JP.eucjp") (source "ja_JP")
14737 (charset "EUC-JP")))
14741 The compiled locale definitions are available at
14742 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
14743 version, which is the default location where the GNU@tie{}libc provided
14744 by Guix looks for locale data. This can be overridden using the
14745 @env{LOCPATH} environment variable (@pxref{locales-and-locpath,
14746 @env{LOCPATH} and locale packages}).
14748 The @code{locale-definition} form is provided by the @code{(gnu system
14749 locale)} module. Details are given below.
14751 @deftp {Data Type} locale-definition
14752 This is the data type of a locale definition.
14757 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
14758 Reference Manual}, for more information on locale names.
14760 @item @code{source}
14761 The name of the source for that locale. This is typically the
14762 @code{@var{language}_@var{territory}} part of the locale name.
14764 @item @code{charset} (default: @code{"UTF-8"})
14765 The ``character set'' or ``code set'' for that locale,
14766 @uref{https://www.iana.org/assignments/character-sets, as defined by
14772 @defvr {Scheme Variable} %default-locale-definitions
14773 A list of commonly used UTF-8 locales, used as the default
14774 value of the @code{locale-definitions} field of @code{operating-system}
14777 @cindex locale name
14778 @cindex normalized codeset in locale names
14779 These locale definitions use the @dfn{normalized codeset} for the part
14780 that follows the dot in the name (@pxref{Using gettextized software,
14781 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
14782 instance it has @code{uk_UA.utf8} but @emph{not}, say,
14783 @code{uk_UA.UTF-8}.
14786 @subsection Locale Data Compatibility Considerations
14788 @cindex incompatibility, of locale data
14789 @code{operating-system} declarations provide a @code{locale-libcs} field
14790 to specify the GNU@tie{}libc packages that are used to compile locale
14791 declarations (@pxref{operating-system Reference}). ``Why would I
14792 care?'', you may ask. Well, it turns out that the binary format of
14793 locale data is occasionally incompatible from one libc version to
14796 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
14797 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
14798 For instance, a program linked against libc version 2.21 is unable to
14799 read locale data produced with libc 2.22; worse, that program
14800 @emph{aborts} instead of simply ignoring the incompatible locale
14801 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
14802 the incompatible locale data, which is already an improvement.}.
14803 Similarly, a program linked against libc 2.22 can read most, but not
14804 all, of the locale data from libc 2.21 (specifically, @env{LC_COLLATE}
14805 data is incompatible); thus calls to @code{setlocale} may fail, but
14806 programs will not abort.
14808 The ``problem'' with Guix is that users have a lot of freedom: They can
14809 choose whether and when to upgrade software in their profiles, and might
14810 be using a libc version different from the one the system administrator
14811 used to build the system-wide locale data.
14813 Fortunately, unprivileged users can also install their own locale data
14814 and define @env{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
14815 @env{GUIX_LOCPATH} and locale packages}).
14817 Still, it is best if the system-wide locale data at
14818 @file{/run/current-system/locale} is built for all the libc versions
14819 actually in use on the system, so that all the programs can access
14820 it---this is especially crucial on a multi-user system. To do that, the
14821 administrator can specify several libc packages in the
14822 @code{locale-libcs} field of @code{operating-system}:
14825 (use-package-modules base)
14829 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
14832 This example would lead to a system containing locale definitions for
14833 both libc 2.21 and the current version of libc in
14834 @file{/run/current-system/locale}.
14840 @cindex system services
14841 An important part of preparing an @code{operating-system} declaration is
14842 listing @dfn{system services} and their configuration (@pxref{Using the
14843 Configuration System}). System services are typically daemons launched
14844 when the system boots, or other actions needed at that time---e.g.,
14845 configuring network access.
14847 Guix has a broad definition of ``service'' (@pxref{Service
14848 Composition}), but many services are managed by the GNU@tie{}Shepherd
14849 (@pxref{Shepherd Services}). On a running system, the @command{herd}
14850 command allows you to list the available services, show their status,
14851 start and stop them, or do other specific operations (@pxref{Jump
14852 Start,,, shepherd, The GNU Shepherd Manual}). For example:
14858 The above command, run as @code{root}, lists the currently defined
14859 services. The @command{herd doc} command shows a synopsis of the given
14860 service and its associated actions:
14864 Run libc's name service cache daemon (nscd).
14866 # herd doc nscd action invalidate
14867 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
14870 The @command{start}, @command{stop}, and @command{restart} sub-commands
14871 have the effect you would expect. For instance, the commands below stop
14872 the nscd service and restart the Xorg display server:
14876 Service nscd has been stopped.
14877 # herd restart xorg-server
14878 Service xorg-server has been stopped.
14879 Service xorg-server has been started.
14882 The following sections document the available services, starting with
14883 the core services, that may be used in an @code{operating-system}
14887 * Base Services:: Essential system services.
14888 * Scheduled Job Execution:: The mcron service.
14889 * Log Rotation:: The rottlog service.
14890 * Networking Services:: Network setup, SSH daemon, etc.
14891 * Unattended Upgrades:: Automated system upgrades.
14892 * X Window:: Graphical display.
14893 * Printing Services:: Local and remote printer support.
14894 * Desktop Services:: D-Bus and desktop services.
14895 * Sound Services:: ALSA and Pulseaudio services.
14896 * Database Services:: SQL databases, key-value stores, etc.
14897 * Mail Services:: IMAP, POP3, SMTP, and all that.
14898 * Messaging Services:: Messaging services.
14899 * Telephony Services:: Telephony services.
14900 * File-Sharing Services:: File-sharing services.
14901 * Monitoring Services:: Monitoring services.
14902 * Kerberos Services:: Kerberos services.
14903 * LDAP Services:: LDAP services.
14904 * Web Services:: Web servers.
14905 * Certificate Services:: TLS certificates via Let's Encrypt.
14906 * DNS Services:: DNS daemons.
14907 * VPN Services:: VPN daemons.
14908 * Network File System:: NFS related services.
14909 * Continuous Integration:: Cuirass and Laminar services.
14910 * Power Management Services:: Extending battery life.
14911 * Audio Services:: The MPD.
14912 * Virtualization Services:: Virtualization services.
14913 * Version Control Services:: Providing remote access to Git repositories.
14914 * Game Services:: Game servers.
14915 * PAM Mount Service:: Service to mount volumes when logging in.
14916 * Guix Services:: Services relating specifically to Guix.
14917 * Linux Services:: Services tied to the Linux kernel.
14918 * Hurd Services:: Services specific for a Hurd System.
14919 * Miscellaneous Services:: Other services.
14922 @node Base Services
14923 @subsection Base Services
14925 The @code{(gnu services base)} module provides definitions for the basic
14926 services that one expects from the system. The services exported by
14927 this module are listed below.
14929 @defvr {Scheme Variable} %base-services
14930 This variable contains a list of basic services (@pxref{Service Types
14931 and Services}, for more information on service objects) one would
14932 expect from the system: a login service (mingetty) on each tty, syslogd,
14933 the libc name service cache daemon (nscd), the udev device manager, and
14936 This is the default value of the @code{services} field of
14937 @code{operating-system} declarations. Usually, when customizing a
14938 system, you will want to append services to @code{%base-services}, like
14942 (append (list (service avahi-service-type)
14943 (service openssh-service-type))
14948 @defvr {Scheme Variable} special-files-service-type
14949 This is the service that sets up ``special files'' such as
14950 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
14952 The value associated with @code{special-files-service-type} services
14953 must be a list of tuples where the first element is the ``special file''
14954 and the second element is its target. By default it is:
14956 @cindex @file{/bin/sh}
14957 @cindex @file{sh}, in @file{/bin}
14959 `(("/bin/sh" ,(file-append bash "/bin/sh")))
14962 @cindex @file{/usr/bin/env}
14963 @cindex @file{env}, in @file{/usr/bin}
14964 If you want to add, say, @code{/usr/bin/env} to your system, you can
14968 `(("/bin/sh" ,(file-append bash "/bin/sh"))
14969 ("/usr/bin/env" ,(file-append coreutils "/bin/env")))
14972 Since this is part of @code{%base-services}, you can use
14973 @code{modify-services} to customize the set of special files
14974 (@pxref{Service Reference, @code{modify-services}}). But the simple way
14975 to add a special file is @i{via} the @code{extra-special-file} procedure
14979 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
14980 Use @var{target} as the ``special file'' @var{file}.
14982 For example, adding the following lines to the @code{services} field of
14983 your operating system declaration leads to a @file{/usr/bin/env}
14987 (extra-special-file "/usr/bin/env"
14988 (file-append coreutils "/bin/env"))
14992 @deffn {Scheme Procedure} host-name-service @var{name}
14993 Return a service that sets the host name to @var{name}.
14996 @defvr {Scheme Variable} console-font-service-type
14997 Install the given fonts on the specified ttys (fonts are per
14998 virtual console on the kernel Linux). The value of this service is a list of
14999 tty/font pairs. The font can be the name of a font provided by the @code{kbd}
15000 package or any valid argument to @command{setfont}, as in this example:
15003 `(("tty1" . "LatGrkCyr-8x16")
15004 ("tty2" . ,(file-append
15006 "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
15007 ("tty3" . ,(file-append
15009 "/share/consolefonts/ter-132n"))) ; for HDPI
15013 @deffn {Scheme Procedure} login-service @var{config}
15014 Return a service to run login according to @var{config}, a
15015 @code{<login-configuration>} object, which specifies the message of the day,
15016 among other things.
15019 @deftp {Data Type} login-configuration
15020 This is the data type representing the configuration of login.
15025 @cindex message of the day
15026 A file-like object containing the ``message of the day''.
15028 @item @code{allow-empty-passwords?} (default: @code{#t})
15029 Allow empty passwords by default so that first-time users can log in when
15030 the 'root' account has just been created.
15035 @deffn {Scheme Procedure} mingetty-service @var{config}
15036 Return a service to run mingetty according to @var{config}, a
15037 @code{<mingetty-configuration>} object, which specifies the tty to run, among
15041 @deftp {Data Type} mingetty-configuration
15042 This is the data type representing the configuration of Mingetty, which
15043 provides the default implementation of virtual console log-in.
15048 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
15050 @item @code{auto-login} (default: @code{#f})
15051 When true, this field must be a string denoting the user name under
15052 which the system automatically logs in. When it is @code{#f}, a
15053 user name and password must be entered to log in.
15055 @item @code{login-program} (default: @code{#f})
15056 This must be either @code{#f}, in which case the default log-in program
15057 is used (@command{login} from the Shadow tool suite), or a gexp denoting
15058 the name of the log-in program.
15060 @item @code{login-pause?} (default: @code{#f})
15061 When set to @code{#t} in conjunction with @var{auto-login}, the user
15062 will have to press a key before the log-in shell is launched.
15064 @item @code{clear-on-logout?} (default: @code{#t})
15065 When set to @code{#t}, the screen will be cleared after logout.
15067 @item @code{mingetty} (default: @var{mingetty})
15068 The Mingetty package to use.
15073 @deffn {Scheme Procedure} agetty-service @var{config}
15074 Return a service to run agetty according to @var{config}, an
15075 @code{<agetty-configuration>} object, which specifies the tty to run,
15076 among other things.
15079 @deftp {Data Type} agetty-configuration
15080 This is the data type representing the configuration of agetty, which
15081 implements virtual and serial console log-in. See the @code{agetty(8)}
15082 man page for more information.
15087 The name of the console this agetty runs on, as a string---e.g.,
15088 @code{"ttyS0"}. This argument is optional, it will default to
15089 a reasonable default serial port used by the kernel Linux.
15091 For this, if there is a value for an option @code{agetty.tty} in the kernel
15092 command line, agetty will extract the device name of the serial port
15093 from it and use that.
15095 If not and if there is a value for an option @code{console} with a tty in
15096 the Linux command line, agetty will extract the device name of the
15097 serial port from it and use that.
15099 In both cases, agetty will leave the other serial device settings
15100 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
15103 @item @code{baud-rate} (default: @code{#f})
15104 A string containing a comma-separated list of one or more baud rates, in
15107 @item @code{term} (default: @code{#f})
15108 A string containing the value used for the @env{TERM} environment
15111 @item @code{eight-bits?} (default: @code{#f})
15112 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
15115 @item @code{auto-login} (default: @code{#f})
15116 When passed a login name, as a string, the specified user will be logged
15117 in automatically without prompting for their login name or password.
15119 @item @code{no-reset?} (default: @code{#f})
15120 When @code{#t}, don't reset terminal cflags (control modes).
15122 @item @code{host} (default: @code{#f})
15123 This accepts a string containing the ``login_host'', which will be written
15124 into the @file{/var/run/utmpx} file.
15126 @item @code{remote?} (default: @code{#f})
15127 When set to @code{#t} in conjunction with @var{host}, this will add an
15128 @code{-r} fakehost option to the command line of the login program
15129 specified in @var{login-program}.
15131 @item @code{flow-control?} (default: @code{#f})
15132 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
15134 @item @code{no-issue?} (default: @code{#f})
15135 When set to @code{#t}, the contents of the @file{/etc/issue} file will
15136 not be displayed before presenting the login prompt.
15138 @item @code{init-string} (default: @code{#f})
15139 This accepts a string that will be sent to the tty or modem before
15140 sending anything else. It can be used to initialize a modem.
15142 @item @code{no-clear?} (default: @code{#f})
15143 When set to @code{#t}, agetty will not clear the screen before showing
15146 @item @code{login-program} (default: (file-append shadow "/bin/login"))
15147 This must be either a gexp denoting the name of a log-in program, or
15148 unset, in which case the default value is the @command{login} from the
15151 @item @code{local-line} (default: @code{#f})
15152 Control the CLOCAL line flag. This accepts one of three symbols as
15153 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
15154 the default value chosen by agetty is @code{'auto}.
15156 @item @code{extract-baud?} (default: @code{#f})
15157 When set to @code{#t}, instruct agetty to try to extract the baud rate
15158 from the status messages produced by certain types of modems.
15160 @item @code{skip-login?} (default: @code{#f})
15161 When set to @code{#t}, do not prompt the user for a login name. This
15162 can be used with @var{login-program} field to use non-standard login
15165 @item @code{no-newline?} (default: @code{#f})
15166 When set to @code{#t}, do not print a newline before printing the
15167 @file{/etc/issue} file.
15169 @c Is this dangerous only when used with login-program, or always?
15170 @item @code{login-options} (default: @code{#f})
15171 This option accepts a string containing options that are passed to the
15172 login program. When used with the @var{login-program}, be aware that a
15173 malicious user could try to enter a login name containing embedded
15174 options that could be parsed by the login program.
15176 @item @code{login-pause} (default: @code{#f})
15177 When set to @code{#t}, wait for any key before showing the login prompt.
15178 This can be used in conjunction with @var{auto-login} to save memory by
15179 lazily spawning shells.
15181 @item @code{chroot} (default: @code{#f})
15182 Change root to the specified directory. This option accepts a directory
15185 @item @code{hangup?} (default: @code{#f})
15186 Use the Linux system call @code{vhangup} to do a virtual hangup of the
15187 specified terminal.
15189 @item @code{keep-baud?} (default: @code{#f})
15190 When set to @code{#t}, try to keep the existing baud rate. The baud
15191 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
15194 @item @code{timeout} (default: @code{#f})
15195 When set to an integer value, terminate if no user name could be read
15196 within @var{timeout} seconds.
15198 @item @code{detect-case?} (default: @code{#f})
15199 When set to @code{#t}, turn on support for detecting an uppercase-only
15200 terminal. This setting will detect a login name containing only
15201 uppercase letters as indicating an uppercase-only terminal and turn on
15202 some upper-to-lower case conversions. Note that this will not support
15203 Unicode characters.
15205 @item @code{wait-cr?} (default: @code{#f})
15206 When set to @code{#t}, wait for the user or modem to send a
15207 carriage-return or linefeed character before displaying
15208 @file{/etc/issue} or login prompt. This is typically used with the
15209 @var{init-string} option.
15211 @item @code{no-hints?} (default: @code{#f})
15212 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
15215 @item @code{no-hostname?} (default: @code{#f})
15216 By default, the hostname is printed. When this option is set to
15217 @code{#t}, no hostname will be shown at all.
15219 @item @code{long-hostname?} (default: @code{#f})
15220 By default, the hostname is only printed until the first dot. When this
15221 option is set to @code{#t}, the fully qualified hostname by
15222 @code{gethostname} or @code{getaddrinfo} is shown.
15224 @item @code{erase-characters} (default: @code{#f})
15225 This option accepts a string of additional characters that should be
15226 interpreted as backspace when the user types their login name.
15228 @item @code{kill-characters} (default: @code{#f})
15229 This option accepts a string that should be interpreted to mean ``ignore
15230 all previous characters'' (also called a ``kill'' character) when the user
15231 types their login name.
15233 @item @code{chdir} (default: @code{#f})
15234 This option accepts, as a string, a directory path that will be changed
15237 @item @code{delay} (default: @code{#f})
15238 This options accepts, as an integer, the number of seconds to sleep
15239 before opening the tty and displaying the login prompt.
15241 @item @code{nice} (default: @code{#f})
15242 This option accepts, as an integer, the nice value with which to run the
15243 @command{login} program.
15245 @item @code{extra-options} (default: @code{'()})
15246 This option provides an ``escape hatch'' for the user to provide arbitrary
15247 command-line arguments to @command{agetty} as a list of strings.
15252 @deffn {Scheme Procedure} kmscon-service-type @var{config}
15253 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
15254 according to @var{config}, a @code{<kmscon-configuration>} object, which
15255 specifies the tty to run, among other things.
15258 @deftp {Data Type} kmscon-configuration
15259 This is the data type representing the configuration of Kmscon, which
15260 implements virtual console log-in.
15264 @item @code{virtual-terminal}
15265 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
15267 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
15268 A gexp denoting the name of the log-in program. The default log-in program is
15269 @command{login} from the Shadow tool suite.
15271 @item @code{login-arguments} (default: @code{'("-p")})
15272 A list of arguments to pass to @command{login}.
15274 @item @code{auto-login} (default: @code{#f})
15275 When passed a login name, as a string, the specified user will be logged
15276 in automatically without prompting for their login name or password.
15278 @item @code{hardware-acceleration?} (default: #f)
15279 Whether to use hardware acceleration.
15281 @item @code{font-engine} (default: @code{"pango"})
15282 Font engine used in Kmscon.
15284 @item @code{font-size} (default: @code{12})
15285 Font size used in Kmscon.
15287 @item @code{kmscon} (default: @var{kmscon})
15288 The Kmscon package to use.
15293 @cindex name service cache daemon
15295 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
15296 [#:name-services '()]
15297 Return a service that runs the libc name service cache daemon (nscd) with the
15298 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
15299 Service Switch}, for an example.
15301 For convenience, the Shepherd service for nscd provides the following actions:
15305 @cindex cache invalidation, nscd
15306 @cindex nscd, cache invalidation
15307 This invalidate the given cache. For instance, running:
15310 herd invalidate nscd hosts
15314 invalidates the host name lookup cache of nscd.
15317 Running @command{herd statistics nscd} displays information about nscd usage
15323 @defvr {Scheme Variable} %nscd-default-configuration
15324 This is the default @code{<nscd-configuration>} value (see below) used
15325 by @code{nscd-service}. It uses the caches defined by
15326 @code{%nscd-default-caches}; see below.
15329 @deftp {Data Type} nscd-configuration
15330 This is the data type representing the name service cache daemon (nscd)
15335 @item @code{name-services} (default: @code{'()})
15336 List of packages denoting @dfn{name services} that must be visible to
15337 the nscd---e.g., @code{(list @var{nss-mdns})}.
15339 @item @code{glibc} (default: @var{glibc})
15340 Package object denoting the GNU C Library providing the @command{nscd}
15343 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
15344 Name of the nscd log file. This is where debugging output goes when
15345 @code{debug-level} is strictly positive.
15347 @item @code{debug-level} (default: @code{0})
15348 Integer denoting the debugging levels. Higher numbers mean that more
15349 debugging output is logged.
15351 @item @code{caches} (default: @code{%nscd-default-caches})
15352 List of @code{<nscd-cache>} objects denoting things to be cached; see
15358 @deftp {Data Type} nscd-cache
15359 Data type representing a cache database of nscd and its parameters.
15363 @item @code{database}
15364 This is a symbol representing the name of the database to be cached.
15365 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
15366 @code{services}, which designate the corresponding NSS database
15367 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
15369 @item @code{positive-time-to-live}
15370 @itemx @code{negative-time-to-live} (default: @code{20})
15371 A number representing the number of seconds during which a positive or
15372 negative lookup result remains in cache.
15374 @item @code{check-files?} (default: @code{#t})
15375 Whether to check for updates of the files corresponding to
15378 For instance, when @var{database} is @code{hosts}, setting this flag
15379 instructs nscd to check for updates in @file{/etc/hosts} and to take
15382 @item @code{persistent?} (default: @code{#t})
15383 Whether the cache should be stored persistently on disk.
15385 @item @code{shared?} (default: @code{#t})
15386 Whether the cache should be shared among users.
15388 @item @code{max-database-size} (default: 32@tie{}MiB)
15389 Maximum size in bytes of the database cache.
15391 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
15392 @c settings, so leave them out.
15397 @defvr {Scheme Variable} %nscd-default-caches
15398 List of @code{<nscd-cache>} objects used by default by
15399 @code{nscd-configuration} (see above).
15401 It enables persistent and aggressive caching of service and host name
15402 lookups. The latter provides better host name lookup performance,
15403 resilience in the face of unreliable name servers, and also better
15404 privacy---often the result of host name lookups is in local cache, so
15405 external name servers do not even need to be queried.
15408 @anchor{syslog-configuration-type}
15411 @deftp {Data Type} syslog-configuration
15412 This data type represents the configuration of the syslog daemon.
15415 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
15416 The syslog daemon to use.
15418 @item @code{config-file} (default: @code{%default-syslog.conf})
15419 The syslog configuration file to use.
15424 @anchor{syslog-service}
15426 @deffn {Scheme Procedure} syslog-service @var{config}
15427 Return a service that runs a syslog daemon according to @var{config}.
15429 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
15430 information on the configuration file syntax.
15433 @defvr {Scheme Variable} guix-service-type
15434 This is the type of the service that runs the build daemon,
15435 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
15436 @code{guix-configuration} record as described below.
15439 @anchor{guix-configuration-type}
15440 @deftp {Data Type} guix-configuration
15441 This data type represents the configuration of the Guix build daemon.
15442 @xref{Invoking guix-daemon}, for more information.
15445 @item @code{guix} (default: @var{guix})
15446 The Guix package to use.
15448 @item @code{build-group} (default: @code{"guixbuild"})
15449 Name of the group for build user accounts.
15451 @item @code{build-accounts} (default: @code{10})
15452 Number of build user accounts to create.
15454 @item @code{authorize-key?} (default: @code{#t})
15455 @cindex substitutes, authorization thereof
15456 Whether to authorize the substitute keys listed in
15457 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
15458 (@pxref{Substitutes}).
15460 When @code{authorize-key?} is true, @file{/etc/guix/acl} cannot be
15461 changed by invoking @command{guix archive --authorize}. You must
15462 instead adjust @code{guix-configuration} as you wish and reconfigure the
15463 system. This ensures that your operating system configuration file is
15467 When booting or reconfiguring to a system where @code{authorize-key?}
15468 is true, the existing @file{/etc/guix/acl} file is backed up as
15469 @file{/etc/guix/acl.bak} if it was determined to be a manually modified
15470 file. This is to facilitate migration from earlier versions, which
15471 allowed for in-place modifications to @file{/etc/guix/acl}.
15474 @vindex %default-authorized-guix-keys
15475 @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
15476 The list of authorized key files for archive imports, as a list of
15477 string-valued gexps (@pxref{Invoking guix archive}). By default, it
15478 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
15479 See @code{substitute-urls} below for an example on how to change it.
15481 @item @code{use-substitutes?} (default: @code{#t})
15482 Whether to use substitutes.
15484 @item @code{substitute-urls} (default: @code{%default-substitute-urls})
15485 The list of URLs where to look for substitutes by default.
15487 Suppose you would like to fetch substitutes from @code{guix.example.org}
15488 in addition to @code{@value{SUBSTITUTE-SERVER}}. You will need to do
15489 two things: (1) add @code{guix.example.org} to @code{substitute-urls},
15490 and (2) authorize its signing key, having done appropriate checks
15491 (@pxref{Substitute Server Authorization}). The configuration below does
15495 (guix-configuration
15497 (append (list "https://guix.example.org")
15498 %default-substitute-urls))
15500 (append (list (local-file "./guix.example.org-key.pub"))
15501 %default-authorized-guix-keys)))
15504 This example assumes that the file @file{./guix.example.org-key.pub}
15505 contains the public key that @code{guix.example.org} uses to sign
15508 @item @code{max-silent-time} (default: @code{0})
15509 @itemx @code{timeout} (default: @code{0})
15510 The number of seconds of silence and the number of seconds of activity,
15511 respectively, after which a build process times out. A value of zero
15512 disables the timeout.
15514 @item @code{log-compression} (default: @code{'bzip2})
15515 The type of compression used for build logs---one of @code{gzip},
15516 @code{bzip2}, or @code{none}.
15518 @item @code{discover?} (default: @code{#f})
15519 Whether to discover substitute servers on the local network using mDNS
15522 @item @code{extra-options} (default: @code{'()})
15523 List of extra command-line options for @command{guix-daemon}.
15525 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
15526 File where @command{guix-daemon}'s standard output and standard error
15529 @cindex HTTP proxy, for @code{guix-daemon}
15530 @cindex proxy, for @code{guix-daemon} HTTP access
15531 @item @code{http-proxy} (default: @code{#f})
15532 The URL of the HTTP and HTTPS proxy used for downloading fixed-output
15533 derivations and substitutes.
15535 It is also possible to change the daemon's proxy at run time through the
15536 @code{set-http-proxy} action, which restarts it:
15539 herd set-http-proxy guix-daemon http://localhost:8118
15542 To clear the proxy settings, run:
15545 herd set-http-proxy guix-daemon
15548 @item @code{tmpdir} (default: @code{#f})
15549 A directory path where the @command{guix-daemon} will perform builds.
15554 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
15555 Run @var{udev}, which populates the @file{/dev} directory dynamically.
15556 udev rules can be provided as a list of files through the @var{rules}
15557 variable. The procedures @code{udev-rule}, @code{udev-rules-service}
15558 and @code{file->udev-rule} from @code{(gnu services base)} simplify the
15559 creation of such rule files.
15561 The @command{herd rules udev} command, as root, returns the name of the
15562 directory containing all the active udev rules.
15565 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
15566 Return a udev-rule file named @var{file-name} containing the rules
15567 defined by the @var{contents} literal.
15569 In the following example, a rule for a USB device is defined to be
15570 stored in the file @file{90-usb-thing.rules}. The rule runs a script
15571 upon detecting a USB device with a given product identifier.
15574 (define %example-udev-rule
15576 "90-usb-thing.rules"
15577 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
15578 "ATTR@{product@}==\"Example\", "
15579 "RUN+=\"/path/to/script\"")))
15583 @deffn {Scheme Procedure} udev-rules-service [@var{name} @var{rules}] @
15584 [#:groups @var{groups}]
15585 Return a service that extends @code{udev-service-type } with @var{rules}
15586 and @code{account-service-type} with @var{groups} as system groups.
15587 This works by creating a singleton service type
15588 @code{@var{name}-udev-rules}, of which the returned service is an
15591 Here we show how it can be used to extend @code{udev-service-type} with the
15592 previously defined rule @code{%example-udev-rule}.
15598 (cons (udev-rules-service 'usb-thing %example-udev-rule)
15599 %desktop-services)))
15603 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
15604 Return a udev file named @var{file-name} containing the rules defined
15605 within @var{file}, a file-like object.
15607 The following example showcases how we can use an existing rule file.
15610 (use-modules (guix download) ;for url-fetch
15611 (guix packages) ;for origin
15614 (define %android-udev-rules
15616 "51-android-udev.rules"
15617 (let ((version "20170910"))
15620 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
15621 "android-udev-rules/" version "/51-android.rules"))
15623 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
15627 Additionally, Guix package definitions can be included in @var{rules} in
15628 order to extend the udev rules with the definitions found under their
15629 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
15630 @var{file->udev-rule} example, we could have used the
15631 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
15632 packages android)} module.
15634 The following example shows how to use the @var{android-udev-rules}
15635 package so that the Android tool @command{adb} can detect devices
15636 without root privileges. It also details how to create the
15637 @code{adbusers} group, which is required for the proper functioning of
15638 the rules defined within the @code{android-udev-rules} package. To
15639 create such a group, we must define it both as part of the
15640 @code{supplementary-groups} of our @code{user-account} declaration, as
15641 well as in the @var{groups} of the @code{udev-rules-service} procedure.
15644 (use-modules (gnu packages android) ;for android-udev-rules
15645 (gnu system shadow) ;for user-group
15650 (users (cons (user-account
15652 (supplementary-groups
15653 '("adbusers" ;for adb
15654 "wheel" "netdev" "audio" "video")))))
15657 (cons (udev-rules-service 'android android-udev-rules
15658 #:groups '("adbusers"))
15659 %desktop-services)))
15662 @defvr {Scheme Variable} urandom-seed-service-type
15663 Save some entropy in @code{%random-seed-file} to seed @file{/dev/urandom}
15664 when rebooting. It also tries to seed @file{/dev/urandom} from
15665 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
15669 @defvr {Scheme Variable} %random-seed-file
15670 This is the name of the file where some random bytes are saved by
15671 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
15672 It defaults to @file{/var/lib/random-seed}.
15677 @defvr {Scheme Variable} gpm-service-type
15678 This is the type of the service that runs GPM, the @dfn{general-purpose
15679 mouse daemon}, which provides mouse support to the Linux console. GPM
15680 allows users to use the mouse in the console, notably to select, copy,
15683 The value for services of this type must be a @code{gpm-configuration}
15684 (see below). This service is not part of @code{%base-services}.
15687 @deftp {Data Type} gpm-configuration
15688 Data type representing the configuration of GPM.
15691 @item @code{options} (default: @code{%default-gpm-options})
15692 Command-line options passed to @command{gpm}. The default set of
15693 options instruct @command{gpm} to listen to mouse events on
15694 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
15697 @item @code{gpm} (default: @code{gpm})
15698 The GPM package to use.
15703 @anchor{guix-publish-service-type}
15704 @deffn {Scheme Variable} guix-publish-service-type
15705 This is the service type for @command{guix publish} (@pxref{Invoking
15706 guix publish}). Its value must be a @code{guix-publish-configuration}
15707 object, as described below.
15709 This assumes that @file{/etc/guix} already contains a signing key pair as
15710 created by @command{guix archive --generate-key} (@pxref{Invoking guix
15711 archive}). If that is not the case, the service will fail to start.
15714 @deftp {Data Type} guix-publish-configuration
15715 Data type representing the configuration of the @code{guix publish}
15719 @item @code{guix} (default: @code{guix})
15720 The Guix package to use.
15722 @item @code{port} (default: @code{80})
15723 The TCP port to listen for connections.
15725 @item @code{host} (default: @code{"localhost"})
15726 The host (and thus, network interface) to listen to. Use
15727 @code{"0.0.0.0"} to listen on all the network interfaces.
15729 @item @code{advertise?} (default: @code{#f})
15730 When true, advertise the service on the local network @i{via} the DNS-SD
15731 protocol, using Avahi.
15733 This allows neighboring Guix devices with discovery on (see
15734 @code{guix-configuration} above) to discover this @command{guix publish}
15735 instance and to automatically download substitutes from it.
15737 @item @code{compression} (default: @code{'(("gzip" 3) ("zstd" 3))})
15738 This is a list of compression method/level tuple used when compressing
15739 substitutes. For example, to compress all substitutes with @emph{both} lzip
15740 at level 7 and gzip at level 9, write:
15743 '(("lzip" 7) ("gzip" 9))
15746 Level 9 achieves the best compression ratio at the expense of increased CPU
15747 usage, whereas level 1 achieves fast compression. @xref{Invoking guix
15748 publish}, for more information on the available compression methods and
15749 the tradeoffs involved.
15751 An empty list disables compression altogether.
15753 @item @code{nar-path} (default: @code{"nar"})
15754 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
15755 publish, @option{--nar-path}}, for details.
15757 @item @code{cache} (default: @code{#f})
15758 When it is @code{#f}, disable caching and instead generate archives on
15759 demand. Otherwise, this should be the name of a directory---e.g.,
15760 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
15761 archives and meta-data ready to be sent. @xref{Invoking guix publish,
15762 @option{--cache}}, for more information on the tradeoffs involved.
15764 @item @code{workers} (default: @code{#f})
15765 When it is an integer, this is the number of worker threads used for
15766 caching; when @code{#f}, the number of processors is used.
15767 @xref{Invoking guix publish, @option{--workers}}, for more information.
15769 @item @code{cache-bypass-threshold} (default: 10 MiB)
15770 When @code{cache} is true, this is the maximum size in bytes of a store
15771 item for which @command{guix publish} may bypass its cache in case of a
15772 cache miss. @xref{Invoking guix publish,
15773 @option{--cache-bypass-threshold}}, for more information.
15775 @item @code{ttl} (default: @code{#f})
15776 When it is an integer, this denotes the @dfn{time-to-live} in seconds
15777 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
15778 for more information.
15782 @anchor{rngd-service}
15783 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
15784 [#:device "/dev/hwrng"]
15785 Return a service that runs the @command{rngd} program from @var{rng-tools}
15786 to add @var{device} to the kernel's entropy pool. The service will fail if
15787 @var{device} does not exist.
15790 @anchor{pam-limits-service}
15791 @cindex session limits
15797 @cindex open file descriptors
15798 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
15800 Return a service that installs a configuration file for the
15801 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
15802 @code{pam_limits} module}. The procedure optionally takes a list of
15803 @code{pam-limits-entry} values, which can be used to specify
15804 @code{ulimit} limits and @code{nice} priority limits to user sessions.
15806 The following limits definition sets two hard and soft limits for all
15807 login sessions of users in the @code{realtime} group:
15810 (pam-limits-service
15812 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
15813 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
15816 The first entry increases the maximum realtime priority for
15817 non-privileged processes; the second entry lifts any restriction of the
15818 maximum address space that can be locked in memory. These settings are
15819 commonly used for real-time audio systems.
15821 Another useful example is raising the maximum number of open file
15822 descriptors that can be used:
15825 (pam-limits-service
15827 (pam-limits-entry "*" 'both 'nofile 100000)))
15830 In the above example, the asterisk means the limit should apply to any
15831 user. It is important to ensure the chosen value doesn't exceed the
15832 maximum system value visible in the @file{/proc/sys/fs/file-max} file,
15833 else the users would be prevented from login in. For more information
15834 about the Pluggable Authentication Module (PAM) limits, refer to the
15835 @samp{pam_limits} man page from the @code{linux-pam} package.
15838 @node Scheduled Job Execution
15839 @subsection Scheduled Job Execution
15843 @cindex scheduling jobs
15844 The @code{(gnu services mcron)} module provides an interface to
15845 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
15846 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
15847 Unix @command{cron} daemon; the main difference is that it is
15848 implemented in Guile Scheme, which provides a lot of flexibility when
15849 specifying the scheduling of jobs and their actions.
15851 The example below defines an operating system that runs the
15852 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
15853 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
15854 well as the @command{mkid} command on behalf of an unprivileged user
15855 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
15856 gexps to introduce job definitions that are passed to mcron
15857 (@pxref{G-Expressions}).
15860 (use-modules (guix) (gnu) (gnu services mcron))
15861 (use-package-modules base idutils)
15863 (define updatedb-job
15864 ;; Run 'updatedb' at 3AM every day. Here we write the
15865 ;; job's action as a Scheme procedure.
15866 #~(job '(next-hour '(3))
15868 (execl (string-append #$findutils "/bin/updatedb")
15870 "--prunepaths=/tmp /var/tmp /gnu/store"))))
15872 (define garbage-collector-job
15873 ;; Collect garbage 5 minutes after midnight every day.
15874 ;; The job's action is a shell command.
15875 #~(job "5 0 * * *" ;Vixie cron syntax
15878 (define idutils-job
15879 ;; Update the index database as user "charlie" at 12:15PM
15880 ;; and 19:15PM. This runs from the user's home directory.
15881 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
15882 (string-append #$idutils "/bin/mkid src")
15888 ;; %BASE-SERVICES already includes an instance of
15889 ;; 'mcron-service-type', which we extend with additional
15890 ;; jobs using 'simple-service'.
15891 (services (cons (simple-service 'my-cron-jobs
15893 (list garbage-collector-job
15899 For more complex jobs defined in Scheme where you need control over the top
15900 level, for instance to introduce a @code{use-modules} form, you can move your
15901 code to a separate program using the @code{program-file} procedure of the
15902 @code{(guix gexp)} module (@pxref{G-Expressions}). The example below
15906 (define %battery-alert-job
15907 ;; Beep when the battery percentage falls below %MIN-LEVEL.
15909 '(next-minute (range 0 60 1))
15911 "battery-alert.scm"
15912 (with-imported-modules (source-module-closure
15913 '((guix build utils)))
15915 (use-modules (guix build utils)
15918 (ice-9 textual-ports)
15921 (define %min-level 20)
15923 (setenv "LC_ALL" "C") ;ensure English output
15924 (and-let* ((input-pipe (open-pipe*
15926 #$(file-append acpi "/bin/acpi")))
15927 (output (get-string-all input-pipe))
15928 (m (string-match "Discharging, ([0-9]+)%" output))
15929 (level (string->number (match:substring m 1)))
15930 ((< level %min-level)))
15931 (format #t "warning: Battery level is low (~a%)~%" level)
15932 (invoke #$(file-append beep "/bin/beep") "-r5")))))))
15935 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
15936 for more information on mcron job specifications. Below is the
15937 reference of the mcron service.
15939 On a running system, you can use the @code{schedule} action of the service to
15940 visualize the mcron jobs that will be executed next:
15943 # herd schedule mcron
15947 The example above lists the next five tasks that will be executed, but you can
15948 also specify the number of tasks to display:
15951 # herd schedule mcron 10
15954 @defvr {Scheme Variable} mcron-service-type
15955 This is the type of the @code{mcron} service, whose value is an
15956 @code{mcron-configuration} object.
15958 This service type can be the target of a service extension that provides
15959 it additional job specifications (@pxref{Service Composition}). In
15960 other words, it is possible to define services that provide additional
15964 @deftp {Data Type} mcron-configuration
15965 Data type representing the configuration of mcron.
15968 @item @code{mcron} (default: @var{mcron})
15969 The mcron package to use.
15972 This is a list of gexps (@pxref{G-Expressions}), where each gexp
15973 corresponds to an mcron job specification (@pxref{Syntax, mcron job
15974 specifications,, mcron, GNU@tie{}mcron}).
15980 @subsection Log Rotation
15983 @cindex log rotation
15985 Log files such as those found in @file{/var/log} tend to grow endlessly,
15986 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
15987 their contents in separate files, possibly compressed. The @code{(gnu
15988 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
15989 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
15991 This service is part of @code{%base-services}, and thus enabled by
15992 default, with the default settings, for commonly encountered log files.
15993 The example below shows how to extend it with an additional
15994 @dfn{rotation}, should you need to do that (usually, services that
15995 produce log files already take care of that):
15998 (use-modules (guix) (gnu))
15999 (use-service-modules admin)
16001 (define my-log-files
16002 ;; Log files that I want to rotate.
16003 '("/var/log/something.log" "/var/log/another.log"))
16007 (services (cons (simple-service 'rotate-my-stuff
16008 rottlog-service-type
16009 (list (log-rotation
16011 (files my-log-files))))
16015 @defvr {Scheme Variable} rottlog-service-type
16016 This is the type of the Rottlog service, whose value is a
16017 @code{rottlog-configuration} object.
16019 Other services can extend this one with new @code{log-rotation} objects
16020 (see below), thereby augmenting the set of files to be rotated.
16022 This service type can define mcron jobs (@pxref{Scheduled Job
16023 Execution}) to run the rottlog service.
16026 @deftp {Data Type} rottlog-configuration
16027 Data type representing the configuration of rottlog.
16030 @item @code{rottlog} (default: @code{rottlog})
16031 The Rottlog package to use.
16033 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
16034 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
16035 rottlog, GNU Rot[t]log Manual}).
16037 @item @code{rotations} (default: @code{%default-rotations})
16038 A list of @code{log-rotation} objects as defined below.
16041 This is a list of gexps where each gexp corresponds to an mcron job
16042 specification (@pxref{Scheduled Job Execution}).
16046 @deftp {Data Type} log-rotation
16047 Data type representing the rotation of a group of log files.
16049 Taking an example from the Rottlog manual (@pxref{Period Related File
16050 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
16056 (files '("/var/log/apache/*"))
16057 (options '("storedir apache-archives"
16063 The list of fields is as follows:
16066 @item @code{frequency} (default: @code{'weekly})
16067 The log rotation frequency, a symbol.
16070 The list of files or file glob patterns to rotate.
16072 @item @code{options} (default: @code{'()})
16073 The list of rottlog options for this rotation (@pxref{Configuration
16074 parameters,,, rottlog, GNU Rot[t]lg Manual}).
16076 @item @code{post-rotate} (default: @code{#f})
16077 Either @code{#f} or a gexp to execute once the rotation has completed.
16081 @defvr {Scheme Variable} %default-rotations
16082 Specifies weekly rotation of @code{%rotated-files} and of
16083 @file{/var/log/guix-daemon.log}.
16086 @defvr {Scheme Variable} %rotated-files
16087 The list of syslog-controlled files to be rotated. By default it is:
16088 @code{'("/var/log/messages" "/var/log/secure" "/var/log/debug" \
16089 "/var/log/maillog")}.
16092 @node Networking Services
16093 @subsection Networking Services
16095 The @code{(gnu services networking)} module provides services to configure
16096 the network interface.
16098 @cindex DHCP, networking service
16099 @defvr {Scheme Variable} dhcp-client-service-type
16100 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
16101 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
16102 is the DHCP client package to use, @code{isc-dhcp} by default.
16105 @deffn {Scheme Procedure} dhcpd-service-type
16106 This type defines a service that runs a DHCP daemon. To create a
16107 service of this type, you must supply a @code{<dhcpd-configuration>}.
16111 (service dhcpd-service-type
16112 (dhcpd-configuration
16113 (config-file (local-file "my-dhcpd.conf"))
16114 (interfaces '("enp0s25"))))
16118 @deftp {Data Type} dhcpd-configuration
16120 @item @code{package} (default: @code{isc-dhcp})
16121 The package that provides the DHCP daemon. This package is expected to
16122 provide the daemon at @file{sbin/dhcpd} relative to its output
16123 directory. The default package is the
16124 @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
16125 @item @code{config-file} (default: @code{#f})
16126 The configuration file to use. This is required. It will be passed to
16127 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
16128 object (@pxref{G-Expressions, file-like objects}). See @code{man
16129 dhcpd.conf} for details on the configuration file syntax.
16130 @item @code{version} (default: @code{"4"})
16131 The DHCP version to use. The ISC DHCP server supports the values ``4'',
16132 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
16133 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
16135 @item @code{run-directory} (default: @code{"/run/dhcpd"})
16136 The run directory to use. At service activation time, this directory
16137 will be created if it does not exist.
16138 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
16139 The PID file to use. This corresponds to the @code{-pf} option of
16140 @code{dhcpd}. See @code{man dhcpd} for details.
16141 @item @code{interfaces} (default: @code{'()})
16142 The names of the network interfaces on which dhcpd should listen for
16143 broadcasts. If this list is not empty, then its elements (which must be
16144 strings) will be appended to the @code{dhcpd} invocation when starting
16145 the daemon. It may not be necessary to explicitly specify any
16146 interfaces here; see @code{man dhcpd} for details.
16150 @defvr {Scheme Variable} static-networking-service-type
16151 This is the type for statically-configured network interfaces.
16152 @c TODO Document <static-networking> data structures.
16155 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
16156 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
16157 [#:requirement @code{'(udev)}]
16158 Return a service that starts @var{interface} with address @var{ip}. If
16159 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
16160 it must be a string specifying the default network gateway. @var{requirement}
16161 can be used to declare a dependency on another service before configuring the
16164 This procedure can be called several times, one for each network
16165 interface of interest. Behind the scenes what it does is extend
16166 @code{static-networking-service-type} with additional network interfaces
16172 (static-networking-service "eno1" "192.168.1.82"
16173 #:gateway "192.168.1.2"
16174 #:name-servers '("192.168.1.2"))
16181 @cindex network management
16182 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
16183 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
16184 management daemon that aims to simplify wired and wireless networking.
16186 This service adds the @var{wicd} package to the global profile, providing
16187 several commands to interact with the daemon and configure networking:
16188 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
16189 and @command{wicd-curses} user interfaces.
16192 @cindex ModemManager
16194 @defvr {Scheme Variable} modem-manager-service-type
16195 This is the service type for the
16196 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
16197 service. The value for this service type is a
16198 @code{modem-manager-configuration} record.
16200 This service is part of @code{%desktop-services} (@pxref{Desktop
16204 @deftp {Data Type} modem-manager-configuration
16205 Data type representing the configuration of ModemManager.
16208 @item @code{modem-manager} (default: @code{modem-manager})
16209 The ModemManager package to use.
16214 @cindex USB_ModeSwitch
16215 @cindex Modeswitching
16217 @defvr {Scheme Variable} usb-modeswitch-service-type
16218 This is the service type for the
16219 @uref{https://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch}
16220 service. The value for this service type is
16221 a @code{usb-modeswitch-configuration} record.
16223 When plugged in, some USB modems (and other USB devices) initially present
16224 themselves as a read-only storage medium and not as a modem. They need to be
16225 @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
16226 installs udev rules to automatically modeswitch these devices when they are
16229 This service is part of @code{%desktop-services} (@pxref{Desktop
16233 @deftp {Data Type} usb-modeswitch-configuration
16234 Data type representing the configuration of USB_ModeSwitch.
16237 @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
16238 The USB_ModeSwitch package providing the binaries for modeswitching.
16240 @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
16241 The package providing the device data and udev rules file used by
16244 @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
16245 Which config file to use for the USB_ModeSwitch dispatcher. By default the
16246 config file shipped with USB_ModeSwitch is used which disables logging to
16247 @file{/var/log} among other default settings. If set to @code{#f}, no config
16253 @cindex NetworkManager
16255 @defvr {Scheme Variable} network-manager-service-type
16256 This is the service type for the
16257 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
16258 service. The value for this service type is a
16259 @code{network-manager-configuration} record.
16261 This service is part of @code{%desktop-services} (@pxref{Desktop
16265 @deftp {Data Type} network-manager-configuration
16266 Data type representing the configuration of NetworkManager.
16269 @item @code{network-manager} (default: @code{network-manager})
16270 The NetworkManager package to use.
16272 @item @code{dns} (default: @code{"default"})
16273 Processing mode for DNS, which affects how NetworkManager uses the
16274 @code{resolv.conf} configuration file.
16278 NetworkManager will update @code{resolv.conf} to reflect the nameservers
16279 provided by currently active connections.
16282 NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
16283 @dfn{conditional forwarding} configuration if you are connected to a VPN, and
16284 then update @code{resolv.conf} to point to the local nameserver.
16286 With this setting, you can share your network connection. For example when
16287 you want to share your network connection to another laptop @i{via} an
16288 Ethernet cable, you can open @command{nm-connection-editor} and configure the
16289 Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
16290 and reestablish the connection (or reboot).
16292 You can also set up a @dfn{host-to-guest connection} to QEMU VMs
16293 (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
16294 e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
16295 browser on your host system, or connect to the VM @i{via} SSH
16296 (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
16297 host-to-guest connection, run this command once:
16300 nmcli connection add type tun \
16301 connection.interface-name tap0 \
16302 tun.mode tap tun.owner $(id -u) \
16303 ipv4.method shared \
16304 ipv4.addresses 172.28.112.1/24
16307 Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
16308 @option{-nic tap,ifname=tap0,script=no,downscript=no} to
16309 @command{qemu-system-...}.
16312 NetworkManager will not modify @code{resolv.conf}.
16315 @item @code{vpn-plugins} (default: @code{'()})
16316 This is the list of available plugins for virtual private networks
16317 (VPNs). An example of this is the @code{network-manager-openvpn}
16318 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
16324 @deffn {Scheme Variable} connman-service-type
16325 This is the service type to run @url{https://01.org/connman,Connman},
16326 a network connection manager.
16328 Its value must be an
16329 @code{connman-configuration} record as in this example:
16332 (service connman-service-type
16333 (connman-configuration
16334 (disable-vpn? #t)))
16337 See below for details about @code{connman-configuration}.
16340 @deftp {Data Type} connman-configuration
16341 Data Type representing the configuration of connman.
16344 @item @code{connman} (default: @var{connman})
16345 The connman package to use.
16347 @item @code{disable-vpn?} (default: @code{#f})
16348 When true, disable connman's vpn plugin.
16352 @cindex WPA Supplicant
16353 @defvr {Scheme Variable} wpa-supplicant-service-type
16354 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
16355 supplicant}, an authentication daemon required to authenticate against
16356 encrypted WiFi or ethernet networks.
16359 @deftp {Data Type} wpa-supplicant-configuration
16360 Data type representing the configuration of WPA Supplicant.
16362 It takes the following parameters:
16365 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
16366 The WPA Supplicant package to use.
16368 @item @code{requirement} (default: @code{'(user-processes loopback syslogd)}
16369 List of services that should be started before WPA Supplicant starts.
16371 @item @code{dbus?} (default: @code{#t})
16372 Whether to listen for requests on D-Bus.
16374 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
16375 Where to store the PID file.
16377 @item @code{interface} (default: @code{#f})
16378 If this is set, it must specify the name of a network interface that
16379 WPA supplicant will control.
16381 @item @code{config-file} (default: @code{#f})
16382 Optional configuration file to use.
16384 @item @code{extra-options} (default: @code{'()})
16385 List of additional command-line arguments to pass to the daemon.
16389 @cindex hostapd service, for Wi-Fi access points
16390 @cindex Wi-Fi access points, hostapd service
16391 @defvr {Scheme Variable} hostapd-service-type
16392 This is the service type to run the @uref{https://w1.fi/hostapd/,
16393 hostapd} daemon to set up WiFi (IEEE 802.11) access points and
16394 authentication servers. Its associated value must be a
16395 @code{hostapd-configuration} as shown below:
16398 ;; Use wlan1 to run the access point for "My Network".
16399 (service hostapd-service-type
16400 (hostapd-configuration
16401 (interface "wlan1")
16402 (ssid "My Network")
16407 @deftp {Data Type} hostapd-configuration
16408 This data type represents the configuration of the hostapd service, with
16409 the following fields:
16412 @item @code{package} (default: @code{hostapd})
16413 The hostapd package to use.
16415 @item @code{interface} (default: @code{"wlan0"})
16416 The network interface to run the WiFi access point.
16419 The SSID (@dfn{service set identifier}), a string that identifies this
16422 @item @code{broadcast-ssid?} (default: @code{#t})
16423 Whether to broadcast this SSID.
16425 @item @code{channel} (default: @code{1})
16426 The WiFi channel to use.
16428 @item @code{driver} (default: @code{"nl80211"})
16429 The driver interface type. @code{"nl80211"} is used with all Linux
16430 mac80211 drivers. Use @code{"none"} if building hostapd as a standalone
16431 RADIUS server that does # not control any wireless/wired driver.
16433 @item @code{extra-settings} (default: @code{""})
16434 Extra settings to append as-is to the hostapd configuration file. See
16435 @uref{https://w1.fi/cgit/hostap/plain/hostapd/hostapd.conf} for the
16436 configuration file reference.
16440 @defvr {Scheme Variable} simulated-wifi-service-type
16441 This is the type of a service to simulate WiFi networking, which can be
16442 useful in virtual machines for testing purposes. The service loads the
16444 @uref{https://www.kernel.org/doc/html/latest/networking/mac80211_hwsim/mac80211_hwsim.html,
16445 @code{mac80211_hwsim} module} and starts hostapd to create a pseudo WiFi
16446 network that can be seen on @code{wlan0}, by default.
16448 The service's value is a @code{hostapd-configuration} record.
16452 @defvr {Scheme Variable} iptables-service-type
16453 This is the service type to set up an iptables configuration. iptables is a
16454 packet filtering framework supported by the Linux kernel. This service
16455 supports configuring iptables for both IPv4 and IPv6. A simple example
16456 configuration rejecting all incoming connections except those to the ssh port
16460 (service iptables-service-type
16461 (iptables-configuration
16462 (ipv4-rules (plain-file "iptables.rules" "*filter
16466 -A INPUT -p tcp --dport 22 -j ACCEPT
16467 -A INPUT -j REJECT --reject-with icmp-port-unreachable
16470 (ipv6-rules (plain-file "ip6tables.rules" "*filter
16474 -A INPUT -p tcp --dport 22 -j ACCEPT
16475 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
16481 @deftp {Data Type} iptables-configuration
16482 The data type representing the configuration of iptables.
16485 @item @code{iptables} (default: @code{iptables})
16486 The iptables package that provides @code{iptables-restore} and
16487 @code{ip6tables-restore}.
16488 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
16489 The iptables rules to use. It will be passed to @code{iptables-restore}.
16490 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
16492 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
16493 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
16494 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
16500 @defvr {Scheme Variable} nftables-service-type
16501 This is the service type to set up a nftables configuration. nftables is a
16502 netfilter project that aims to replace the existing iptables, ip6tables,
16503 arptables and ebtables framework. It provides a new packet filtering
16504 framework, a new user-space utility @command{nft}, and a compatibility layer
16505 for iptables. This service comes with a default ruleset
16506 @code{%default-nftables-ruleset} that rejecting all incoming connections
16507 except those to the ssh port 22. To use it, simply write:
16510 (service nftables-service-type)
16514 @deftp {Data Type} nftables-configuration
16515 The data type representing the configuration of nftables.
16518 @item @code{package} (default: @code{nftables})
16519 The nftables package that provides @command{nft}.
16520 @item @code{ruleset} (default: @code{%default-nftables-ruleset})
16521 The nftables ruleset to use. This may be any ``file-like'' object
16522 (@pxref{G-Expressions, file-like objects}).
16526 @cindex NTP (Network Time Protocol), service
16527 @cindex ntpd, service for the Network Time Protocol daemon
16528 @cindex real time clock
16529 @defvr {Scheme Variable} ntp-service-type
16530 This is the type of the service running the @uref{https://www.ntp.org,
16531 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
16532 system clock synchronized with that of the specified NTP servers.
16534 The value of this service is an @code{ntpd-configuration} object, as described
16538 @deftp {Data Type} ntp-configuration
16539 This is the data type for the NTP service configuration.
16542 @item @code{servers} (default: @code{%ntp-servers})
16543 This is the list of servers (@code{<ntp-server>} records) with which
16544 @command{ntpd} will be synchronized. See the @code{ntp-server} data type
16547 @item @code{allow-large-adjustment?} (default: @code{#t})
16548 This determines whether @command{ntpd} is allowed to make an initial
16549 adjustment of more than 1,000 seconds.
16551 @item @code{ntp} (default: @code{ntp})
16552 The NTP package to use.
16556 @defvr {Scheme Variable} %ntp-servers
16557 List of host names used as the default NTP servers. These are servers of the
16558 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
16561 @deftp {Data Type} ntp-server
16562 The data type representing the configuration of a NTP server.
16565 @item @code{type} (default: @code{'server})
16566 The type of the NTP server, given as a symbol. One of @code{'pool},
16567 @code{'server}, @code{'peer}, @code{'broadcast} or @code{'manycastclient}.
16569 @item @code{address}
16570 The address of the server, as a string.
16572 @item @code{options}
16573 NTPD options to use with that specific server, given as a list of option names
16574 and/or of option names and values tuples. The following example define a server
16575 to use with the options @option{iburst} and @option{prefer}, as well as
16576 @option{version} 3 and a @option{maxpoll} time of 16 seconds.
16581 (address "some.ntp.server.org")
16582 (options `(iburst (version 3) (maxpoll 16) prefer))))
16588 @deffn {Scheme Procedure} openntpd-service-type
16589 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
16590 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
16591 clock synchronized with that of the given servers.
16595 openntpd-service-type
16596 (openntpd-configuration
16597 (listen-on '("127.0.0.1" "::1"))
16598 (sensor '("udcf0 correction 70000"))
16599 (constraint-from '("www.gnu.org"))
16600 (constraints-from '("https://www.google.com/"))))
16605 @defvr {Scheme Variable} %openntpd-servers
16606 This variable is a list of the server addresses defined in
16607 @code{%ntp-servers}.
16610 @deftp {Data Type} openntpd-configuration
16612 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
16613 The openntpd executable to use.
16614 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
16615 A list of local IP addresses or hostnames the ntpd daemon should listen on.
16616 @item @code{query-from} (default: @code{'()})
16617 A list of local IP address the ntpd daemon should use for outgoing queries.
16618 @item @code{sensor} (default: @code{'()})
16619 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
16620 will listen to each sensor that actually exists and ignore non-existent ones.
16621 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
16623 @item @code{server} (default: @code{'()})
16624 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
16625 @item @code{servers} (default: @code{%openntp-servers})
16626 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
16627 @item @code{constraint-from} (default: @code{'()})
16628 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
16629 This time information is not used for precision but acts as an authenticated
16630 constraint, thereby reducing the impact of unauthenticated NTP
16631 man-in-the-middle attacks.
16632 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
16634 @item @code{constraints-from} (default: @code{'()})
16635 As with constraint from, specify a list of URLs, IP addresses or hostnames of
16636 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
16637 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
16642 @deffn {Scheme variable} inetd-service-type
16643 This service runs the @command{inetd} (@pxref{inetd invocation,,,
16644 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
16645 connections on internet sockets, and lazily starts the specified server
16646 program when a connection is made on one of these sockets.
16648 The value of this service is an @code{inetd-configuration} object. The
16649 following example configures the @command{inetd} daemon to provide the
16650 built-in @command{echo} service, as well as an smtp service which
16651 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
16652 gateway @code{hostname}:
16657 (inetd-configuration
16661 (socket-type 'stream)
16668 (socket-type 'stream)
16672 (program (file-append openssh "/bin/ssh"))
16674 '("ssh" "-qT" "-i" "/path/to/ssh_key"
16675 "-W" "smtp-server:25" "user@@hostname")))))))
16678 See below for more details about @code{inetd-configuration}.
16681 @deftp {Data Type} inetd-configuration
16682 Data type representing the configuration of @command{inetd}.
16685 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
16686 The @command{inetd} executable to use.
16688 @item @code{entries} (default: @code{'()})
16689 A list of @command{inetd} service entries. Each entry should be created
16690 by the @code{inetd-entry} constructor.
16694 @deftp {Data Type} inetd-entry
16695 Data type representing an entry in the @command{inetd} configuration.
16696 Each entry corresponds to a socket where @command{inetd} will listen for
16700 @item @code{node} (default: @code{#f})
16701 Optional string, a comma-separated list of local addresses
16702 @command{inetd} should use when listening for this service.
16703 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
16704 description of all options.
16706 A string, the name must correspond to an entry in @code{/etc/services}.
16707 @item @code{socket-type}
16708 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
16710 @item @code{protocol}
16711 A string, must correspond to an entry in @code{/etc/protocols}.
16712 @item @code{wait?} (default: @code{#t})
16713 Whether @command{inetd} should wait for the server to exit before
16714 listening to new service requests.
16716 A string containing the user (and, optionally, group) name of the user
16717 as whom the server should run. The group name can be specified in a
16718 suffix, separated by a colon or period, i.e.@: @code{"user"},
16719 @code{"user:group"} or @code{"user.group"}.
16720 @item @code{program} (default: @code{"internal"})
16721 The server program which will serve the requests, or @code{"internal"}
16722 if @command{inetd} should use a built-in service.
16723 @item @code{arguments} (default: @code{'()})
16724 A list strings or file-like objects, which are the server program's
16725 arguments, starting with the zeroth argument, i.e.@: the name of the
16726 program itself. For @command{inetd}'s internal services, this entry
16727 must be @code{'()} or @code{'("internal")}.
16730 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
16731 detailed discussion of each configuration field.
16735 @defvr {Scheme Variable} tor-service-type
16736 This is the type for a service that runs the @uref{https://torproject.org,
16737 Tor} anonymous networking daemon. The service is configured using a
16738 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
16739 @code{tor} unprivileged user, which is a member of the @code{tor} group.
16743 @deftp {Data Type} tor-configuration
16745 @item @code{tor} (default: @code{tor})
16746 The package that provides the Tor daemon. This package is expected to provide
16747 the daemon at @file{bin/tor} relative to its output directory. The default
16748 package is the @uref{https://www.torproject.org, Tor Project's}
16751 @item @code{config-file} (default: @code{(plain-file "empty" "")})
16752 The configuration file to use. It will be appended to a default configuration
16753 file, and the final configuration file will be passed to @code{tor} via its
16754 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
16755 file-like objects}). See @code{man tor} for details on the configuration file
16758 @item @code{hidden-services} (default: @code{'()})
16759 The list of @code{<hidden-service>} records to use. For any hidden service
16760 you include in this list, appropriate configuration to enable the hidden
16761 service will be automatically added to the default configuration file. You
16762 may conveniently create @code{<hidden-service>} records using the
16763 @code{tor-hidden-service} procedure described below.
16765 @item @code{socks-socket-type} (default: @code{'tcp})
16766 The default socket type that Tor should use for its SOCKS socket. This must
16767 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
16768 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
16769 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
16770 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
16773 If you want to customize the SOCKS socket in more detail, leave
16774 @code{socks-socket-type} at its default value of @code{'tcp} and use
16775 @code{config-file} to override the default by providing your own
16776 @code{SocksPort} option.
16778 @item @code{control-socket?} (default: @code{#f})
16779 Whether or not to provide a ``control socket'' by which Tor can be
16780 controlled to, for instance, dynamically instantiate tor onion services.
16781 If @code{#t}, Tor will listen for control commands on the UNIX domain socket
16782 @file{/var/run/tor/control-sock}, which will be made writable by members of the
16788 @cindex hidden service
16789 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
16790 Define a new Tor @dfn{hidden service} called @var{name} and implementing
16791 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
16794 '((22 "127.0.0.1:22")
16795 (80 "127.0.0.1:8080"))
16798 In this example, port 22 of the hidden service is mapped to local port 22, and
16799 port 80 is mapped to local port 8080.
16801 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
16802 the @file{hostname} file contains the @code{.onion} host name for the hidden
16805 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
16806 project's documentation} for more information.
16809 The @code{(gnu services rsync)} module provides the following services:
16811 You might want an rsync daemon if you have files that you want available
16812 so anyone (or just yourself) can download existing files or upload new
16815 @deffn {Scheme Variable} rsync-service-type
16816 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
16817 The value for this service type is a
16818 @command{rsync-configuration} record as in this example:
16821 (service rsync-service-type)
16824 See below for details about @code{rsync-configuration}.
16827 @deftp {Data Type} rsync-configuration
16828 Data type representing the configuration for @code{rsync-service}.
16831 @item @code{package} (default: @var{rsync})
16832 @code{rsync} package to use.
16834 @item @code{port-number} (default: @code{873})
16835 TCP port on which @command{rsync} listens for incoming connections. If port
16836 is less than @code{1024} @command{rsync} needs to be started as the
16837 @code{root} user and group.
16839 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
16840 Name of the file where @command{rsync} writes its PID.
16842 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
16843 Name of the file where @command{rsync} writes its lock file.
16845 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
16846 Name of the file where @command{rsync} writes its log file.
16848 @item @code{use-chroot?} (default: @var{#t})
16849 Whether to use chroot for @command{rsync} shared directory.
16851 @item @code{share-path} (default: @file{/srv/rsync})
16852 Location of the @command{rsync} shared directory.
16854 @item @code{share-comment} (default: @code{"Rsync share"})
16855 Comment of the @command{rsync} shared directory.
16857 @item @code{read-only?} (default: @var{#f})
16858 Read-write permissions to shared directory.
16860 @item @code{timeout} (default: @code{300})
16861 I/O timeout in seconds.
16863 @item @code{user} (default: @var{"root"})
16864 Owner of the @code{rsync} process.
16866 @item @code{group} (default: @var{"root"})
16867 Group of the @code{rsync} process.
16869 @item @code{uid} (default: @var{"rsyncd"})
16870 User name or user ID that file transfers to and from that module should take
16871 place as when the daemon was run as @code{root}.
16873 @item @code{gid} (default: @var{"rsyncd"})
16874 Group name or group ID that will be used when accessing the module.
16879 The @code{(gnu services syncthing)} module provides the following services:
16882 You might want a syncthing daemon if you have files between two or more
16883 computers and want to sync them in real time, safely protected from
16886 @deffn {Scheme Variable} syncthing-service-type
16887 This is the service type for the @uref{https://syncthing.net/,
16888 syncthing} daemon, The value for this service type is a
16889 @command{syncthing-configuration} record as in this example:
16892 (service syncthing-service-type
16893 (syncthing-configuration (user "alice")))
16896 See below for details about @code{syncthing-configuration}.
16898 @deftp {Data Type} syncthing-configuration
16899 Data type representing the configuration for @code{syncthing-service-type}.
16902 @item @code{syncthing} (default: @var{syncthing})
16903 @code{syncthing} package to use.
16905 @item @code{arguments} (default: @var{'()})
16906 List of command-line arguments passing to @code{syncthing} binary.
16908 @item @code{logflags} (default: @var{0})
16909 Sum of logging flags, see
16910 @uref{https://docs.syncthing.net/users/syncthing.html#cmdoption-logflags, Syncthing documentation logflags}.
16912 @item @code{user} (default: @var{#f})
16913 The user as which the Syncthing service is to be run.
16914 This assumes that the specified user exists.
16916 @item @code{group} (default: @var{"users"})
16917 The group as which the Syncthing service is to be run.
16918 This assumes that the specified group exists.
16920 @item @code{home} (default: @var{#f})
16921 Common configuration and data directory. The default configuration
16922 directory is @file{$HOME} of the specified Syncthing @code{user}.
16928 Furthermore, @code{(gnu services ssh)} provides the following services.
16932 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
16933 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
16934 [#:allow-empty-passwords? #f] [#:root-login? #f] @
16935 [#:syslog-output? #t] [#:x11-forwarding? #t] @
16936 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
16937 [#:public-key-authentication? #t] [#:initialize? #t]
16938 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
16939 @var{host-key} must designate a file containing the host key, and readable
16942 When @var{daemonic?} is true, @command{lshd} will detach from the
16943 controlling terminal and log its output to syslogd, unless one sets
16944 @var{syslog-output?} to false. Obviously, it also makes lsh-service
16945 depend on existence of syslogd service. When @var{pid-file?} is true,
16946 @command{lshd} writes its PID to the file called @var{pid-file}.
16948 When @var{initialize?} is true, automatically create the seed and host key
16949 upon service activation if they do not exist yet. This may take long and
16950 require interaction.
16952 When @var{initialize?} is false, it is up to the user to initialize the
16953 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
16954 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
16955 basics,,, lsh, LSH Manual}).
16957 When @var{interfaces} is empty, lshd listens for connections on all the
16958 network interfaces; otherwise, @var{interfaces} must be a list of host names
16961 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
16962 passwords, and @var{root-login?} specifies whether to accept log-ins as
16965 The other options should be self-descriptive.
16970 @deffn {Scheme Variable} openssh-service-type
16971 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
16972 shell daemon, @command{sshd}. Its value must be an
16973 @code{openssh-configuration} record as in this example:
16976 (service openssh-service-type
16977 (openssh-configuration
16978 (x11-forwarding? #t)
16979 (permit-root-login 'without-password)
16981 `(("alice" ,(local-file "alice.pub"))
16982 ("bob" ,(local-file "bob.pub"))))))
16985 See below for details about @code{openssh-configuration}.
16987 This service can be extended with extra authorized keys, as in this
16991 (service-extension openssh-service-type
16992 (const `(("charlie"
16993 ,(local-file "charlie.pub")))))
16997 @deftp {Data Type} openssh-configuration
16998 This is the configuration record for OpenSSH's @command{sshd}.
17001 @item @code{openssh} (default @var{openssh})
17002 The Openssh package to use.
17004 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
17005 Name of the file where @command{sshd} writes its PID.
17007 @item @code{port-number} (default: @code{22})
17008 TCP port on which @command{sshd} listens for incoming connections.
17010 @item @code{permit-root-login} (default: @code{#f})
17011 This field determines whether and when to allow logins as root. If
17012 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
17013 If it's the symbol @code{'without-password}, then root logins are
17014 permitted but not with password-based authentication.
17016 @item @code{allow-empty-passwords?} (default: @code{#f})
17017 When true, users with empty passwords may log in. When false, they may
17020 @item @code{password-authentication?} (default: @code{#t})
17021 When true, users may log in with their password. When false, they have
17022 other authentication methods.
17024 @item @code{public-key-authentication?} (default: @code{#t})
17025 When true, users may log in using public key authentication. When
17026 false, users have to use other authentication method.
17028 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
17029 This is used only by protocol version 2.
17031 @item @code{x11-forwarding?} (default: @code{#f})
17032 When true, forwarding of X11 graphical client connections is
17033 enabled---in other words, @command{ssh} options @option{-X} and
17034 @option{-Y} will work.
17036 @item @code{allow-agent-forwarding?} (default: @code{#t})
17037 Whether to allow agent forwarding.
17039 @item @code{allow-tcp-forwarding?} (default: @code{#t})
17040 Whether to allow TCP forwarding.
17042 @item @code{gateway-ports?} (default: @code{#f})
17043 Whether to allow gateway ports.
17045 @item @code{challenge-response-authentication?} (default: @code{#f})
17046 Specifies whether challenge response authentication is allowed (e.g.@: via
17049 @item @code{use-pam?} (default: @code{#t})
17050 Enables the Pluggable Authentication Module interface. If set to
17051 @code{#t}, this will enable PAM authentication using
17052 @code{challenge-response-authentication?} and
17053 @code{password-authentication?}, in addition to PAM account and session
17054 module processing for all authentication types.
17056 Because PAM challenge response authentication usually serves an
17057 equivalent role to password authentication, you should disable either
17058 @code{challenge-response-authentication?} or
17059 @code{password-authentication?}.
17061 @item @code{print-last-log?} (default: @code{#t})
17062 Specifies whether @command{sshd} should print the date and time of the
17063 last user login when a user logs in interactively.
17065 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
17066 Configures external subsystems (e.g.@: file transfer daemon).
17068 This is a list of two-element lists, each of which containing the
17069 subsystem name and a command (with optional arguments) to execute upon
17072 The command @command{internal-sftp} implements an in-process SFTP
17073 server. Alternatively, one can specify the @command{sftp-server} command:
17075 (service openssh-service-type
17076 (openssh-configuration
17078 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
17081 @item @code{accepted-environment} (default: @code{'()})
17082 List of strings describing which environment variables may be exported.
17084 Each string gets on its own line. See the @code{AcceptEnv} option in
17085 @code{man sshd_config}.
17087 This example allows ssh-clients to export the @env{COLORTERM} variable.
17088 It is set by terminal emulators, which support colors. You can use it in
17089 your shell's resource file to enable colors for the prompt and commands
17090 if this variable is set.
17093 (service openssh-service-type
17094 (openssh-configuration
17095 (accepted-environment '("COLORTERM"))))
17098 @item @code{authorized-keys} (default: @code{'()})
17099 @cindex authorized keys, SSH
17100 @cindex SSH authorized keys
17101 This is the list of authorized keys. Each element of the list is a user
17102 name followed by one or more file-like objects that represent SSH public
17106 (openssh-configuration
17108 `(("rekado" ,(local-file "rekado.pub"))
17109 ("chris" ,(local-file "chris.pub"))
17110 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
17114 registers the specified public keys for user accounts @code{rekado},
17115 @code{chris}, and @code{root}.
17117 Additional authorized keys can be specified @i{via}
17118 @code{service-extension}.
17120 Note that this does @emph{not} interfere with the use of
17121 @file{~/.ssh/authorized_keys}.
17123 @item @code{log-level} (default: @code{'info})
17124 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
17125 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
17126 page for @file{sshd_config} for the full list of level names.
17128 @item @code{extra-content} (default: @code{""})
17129 This field can be used to append arbitrary text to the configuration file. It
17130 is especially useful for elaborate configurations that cannot be expressed
17131 otherwise. This configuration, for example, would generally disable root
17132 logins, but permit them from one specific IP address:
17135 (openssh-configuration
17137 Match Address 192.168.0.1
17138 PermitRootLogin yes"))
17144 @deffn {Scheme Procedure} dropbear-service [@var{config}]
17145 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
17146 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
17149 For example, to specify a Dropbear service listening on port 1234, add
17150 this call to the operating system's @code{services} field:
17153 (dropbear-service (dropbear-configuration
17154 (port-number 1234)))
17158 @deftp {Data Type} dropbear-configuration
17159 This data type represents the configuration of a Dropbear SSH daemon.
17162 @item @code{dropbear} (default: @var{dropbear})
17163 The Dropbear package to use.
17165 @item @code{port-number} (default: 22)
17166 The TCP port where the daemon waits for incoming connections.
17168 @item @code{syslog-output?} (default: @code{#t})
17169 Whether to enable syslog output.
17171 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
17172 File name of the daemon's PID file.
17174 @item @code{root-login?} (default: @code{#f})
17175 Whether to allow @code{root} logins.
17177 @item @code{allow-empty-passwords?} (default: @code{#f})
17178 Whether to allow empty passwords.
17180 @item @code{password-authentication?} (default: @code{#t})
17181 Whether to enable password-based authentication.
17186 @deffn {Scheme Variable} autossh-service-type
17187 This is the type for the @uref{https://www.harding.motd.ca/autossh,
17188 AutoSSH} program that runs a copy of @command{ssh} and monitors it,
17189 restarting it as necessary should it die or stop passing traffic.
17190 AutoSSH can be run manually from the command-line by passing arguments
17191 to the binary @command{autossh} from the package @code{autossh}, but it
17192 can also be run as a Guix service. This latter use case is documented
17195 AutoSSH can be used to forward local traffic to a remote machine using
17196 an SSH tunnel, and it respects the @file{~/.ssh/config} of the user it
17199 For example, to specify a service running autossh as the user
17200 @code{pino} and forwarding all local connections to port @code{8081} to
17201 @code{remote:8081} using an SSH tunnel, add this call to the operating
17202 system's @code{services} field:
17205 (service autossh-service-type
17206 (autossh-configuration
17208 (ssh-options (list "-T" "-N" "-L" "8081:localhost:8081" "remote.net"))))
17212 @deftp {Data Type} autossh-configuration
17213 This data type represents the configuration of an AutoSSH service.
17217 @item @code{user} (default @code{"autossh"})
17218 The user as which the AutoSSH service is to be run.
17219 This assumes that the specified user exists.
17221 @item @code{poll} (default @code{600})
17222 Specifies the connection poll time in seconds.
17224 @item @code{first-poll} (default @code{#f})
17225 Specifies how many seconds AutoSSH waits before the first connection
17226 test. After this first test, polling is resumed at the pace defined in
17227 @code{poll}. When set to @code{#f}, the first poll is not treated
17228 specially and will also use the connection poll specified in
17231 @item @code{gate-time} (default @code{30})
17232 Specifies how many seconds an SSH connection must be active before it is
17233 considered successful.
17235 @item @code{log-level} (default @code{1})
17236 The log level, corresponding to the levels used by syslog---so @code{0}
17237 is the most silent while @code{7} is the chattiest.
17239 @item @code{max-start} (default @code{#f})
17240 The maximum number of times SSH may be (re)started before AutoSSH exits.
17241 When set to @code{#f}, no maximum is configured and AutoSSH may restart indefinitely.
17243 @item @code{message} (default @code{""})
17244 The message to append to the echo message sent when testing connections.
17246 @item @code{port} (default @code{"0"})
17247 The ports used for monitoring the connection. When set to @code{"0"},
17248 monitoring is disabled. When set to @code{"@var{n}"} where @var{n} is
17249 a positive integer, ports @var{n} and @var{n}+1 are used for
17250 monitoring the connection, such that port @var{n} is the base
17251 monitoring port and @code{n+1} is the echo port. When set to
17252 @code{"@var{n}:@var{m}"} where @var{n} and @var{m} are positive
17253 integers, the ports @var{n} and @var{m} are used for monitoring the
17254 connection, such that port @var{n} is the base monitoring port and
17255 @var{m} is the echo port.
17257 @item @code{ssh-options} (default @code{'()})
17258 The list of command-line arguments to pass to @command{ssh} when it is
17259 run. Options @option{-f} and @option{-M} are reserved for AutoSSH and
17260 may cause undefined behaviour.
17266 @deffn {Scheme Variable} webssh-service-type
17267 This is the type for the @uref{https://webssh.huashengdun.org/, WebSSH}
17268 program that runs a web SSH client. WebSSH can be run manually from the
17269 command-line by passing arguments to the binary @command{wssh} from the
17270 package @code{webssh}, but it can also be run as a Guix service. This
17271 latter use case is documented here.
17273 For example, to specify a service running WebSSH on loopback interface
17274 on port @code{8888} with reject policy with a list of allowed to
17275 connection hosts, and NGINX as a reverse-proxy to this service listening
17276 for HTTPS connection, add this call to the operating system's
17277 @code{services} field:
17280 (service webssh-service-type
17281 (webssh-configuration (address "127.0.0.1")
17284 (known-hosts '("localhost ecdsa-sha2-nistp256 AAAA…"
17285 "127.0.0.1 ecdsa-sha2-nistp256 AAAA…"))))
17287 (service nginx-service-type
17288 (nginx-configuration
17291 (nginx-server-configuration
17292 (inherit %webssh-configuration-nginx)
17293 (server-name '("webssh.example.com"))
17294 (listen '("443 ssl"))
17295 (ssl-certificate (letsencrypt-certificate "webssh.example.com"))
17296 (ssl-certificate-key (letsencrypt-key "webssh.example.com"))
17298 (cons (nginx-location-configuration
17299 (uri "/.well-known")
17300 (body '("root /var/www;")))
17301 (nginx-server-configuration-locations %webssh-configuration-nginx))))))))
17305 @deftp {Data Type} webssh-configuration
17306 Data type representing the configuration for @code{webssh-service}.
17309 @item @code{package} (default: @var{webssh})
17310 @code{webssh} package to use.
17312 @item @code{user-name} (default: @var{"webssh"})
17313 User name or user ID that file transfers to and from that module should take
17316 @item @code{group-name} (default: @var{"webssh"})
17317 Group name or group ID that will be used when accessing the module.
17319 @item @code{address} (default: @var{#f})
17320 IP address on which @command{webssh} listens for incoming connections.
17322 @item @code{port} (default: @var{8888})
17323 TCP port on which @command{webssh} listens for incoming connections.
17325 @item @code{policy} (default: @var{#f})
17326 Connection policy. @var{reject} policy requires to specify @var{known-hosts}.
17328 @item @code{known-hosts} (default: @var{'()})
17329 List of hosts which allowed for SSH connection from @command{webssh}.
17331 @item @code{log-file} (default: @file{"/var/log/webssh.log"})
17332 Name of the file where @command{webssh} writes its log file.
17334 @item @code{log-level} (default: @var{#f})
17340 @defvr {Scheme Variable} %facebook-host-aliases
17341 This variable contains a string for use in @file{/etc/hosts}
17342 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
17343 line contains a entry that maps a known server name of the Facebook
17344 on-line service---e.g., @code{www.facebook.com}---to the local
17345 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
17347 This variable is typically used in the @code{hosts-file} field of an
17348 @code{operating-system} declaration (@pxref{operating-system Reference,
17349 @file{/etc/hosts}}):
17352 (use-modules (gnu) (guix))
17355 (host-name "mymachine")
17358 ;; Create a /etc/hosts file with aliases for "localhost"
17359 ;; and "mymachine", as well as for Facebook servers.
17360 (plain-file "hosts"
17361 (string-append (local-host-aliases host-name)
17362 %facebook-host-aliases))))
17365 This mechanism can prevent programs running locally, such as Web
17366 browsers, from accessing Facebook.
17369 The @code{(gnu services avahi)} provides the following definition.
17371 @defvr {Scheme Variable} avahi-service-type
17372 This is the service that runs @command{avahi-daemon}, a system-wide
17373 mDNS/DNS-SD responder that allows for service discovery and
17374 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
17375 Its value must be an @code{avahi-configuration} record---see below.
17377 This service extends the name service cache daemon (nscd) so that it can
17378 resolve @code{.local} host names using
17379 @uref{https://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
17380 Service Switch}, for information on host name resolution.
17382 Additionally, add the @var{avahi} package to the system profile so that
17383 commands such as @command{avahi-browse} are directly usable.
17386 @deftp {Data Type} avahi-configuration
17387 Data type representation the configuration for Avahi.
17391 @item @code{host-name} (default: @code{#f})
17392 If different from @code{#f}, use that as the host name to
17393 publish for this machine; otherwise, use the machine's actual host name.
17395 @item @code{publish?} (default: @code{#t})
17396 When true, allow host names and services to be published (broadcast) over the
17399 @item @code{publish-workstation?} (default: @code{#t})
17400 When true, @command{avahi-daemon} publishes the machine's host name and IP
17401 address via mDNS on the local network. To view the host names published on
17402 your local network, you can run:
17405 avahi-browse _workstation._tcp
17408 @item @code{wide-area?} (default: @code{#f})
17409 When true, DNS-SD over unicast DNS is enabled.
17411 @item @code{ipv4?} (default: @code{#t})
17412 @itemx @code{ipv6?} (default: @code{#t})
17413 These fields determine whether to use IPv4/IPv6 sockets.
17415 @item @code{domains-to-browse} (default: @code{'()})
17416 This is a list of domains to browse.
17420 @deffn {Scheme Variable} openvswitch-service-type
17421 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
17422 service, whose value should be an @code{openvswitch-configuration}
17426 @deftp {Data Type} openvswitch-configuration
17427 Data type representing the configuration of Open vSwitch, a multilayer
17428 virtual switch which is designed to enable massive network automation
17429 through programmatic extension.
17432 @item @code{package} (default: @var{openvswitch})
17433 Package object of the Open vSwitch.
17438 @defvr {Scheme Variable} pagekite-service-type
17439 This is the service type for the @uref{https://pagekite.net, PageKite} service,
17440 a tunneling solution for making localhost servers publicly visible, even from
17441 behind restrictive firewalls or NAT without forwarded ports. The value for
17442 this service type is a @code{pagekite-configuration} record.
17444 Here's an example exposing the local HTTP and SSH daemons:
17447 (service pagekite-service-type
17448 (pagekite-configuration
17449 (kites '("http:@@kitename:localhost:80:@@kitesecret"
17450 "raw/22:@@kitename:localhost:22:@@kitesecret"))
17451 (extra-file "/etc/pagekite.rc")))
17455 @deftp {Data Type} pagekite-configuration
17456 Data type representing the configuration of PageKite.
17459 @item @code{package} (default: @var{pagekite})
17460 Package object of PageKite.
17462 @item @code{kitename} (default: @code{#f})
17463 PageKite name for authenticating to the frontend server.
17465 @item @code{kitesecret} (default: @code{#f})
17466 Shared secret for authenticating to the frontend server. You should probably
17467 put this inside @code{extra-file} instead.
17469 @item @code{frontend} (default: @code{#f})
17470 Connect to the named PageKite frontend server instead of the
17471 @uref{https://pagekite.net,,pagekite.net} service.
17473 @item @code{kites} (default: @code{'("http:@@kitename:localhost:80:@@kitesecret")})
17474 List of service kites to use. Exposes HTTP on port 80 by default. The format
17475 is @code{proto:kitename:host:port:secret}.
17477 @item @code{extra-file} (default: @code{#f})
17478 Extra configuration file to read, which you are expected to create manually.
17479 Use this to add additional options and manage shared secrets out-of-band.
17484 @defvr {Scheme Variable} yggdrasil-service-type
17485 The service type for connecting to the @uref{https://yggdrasil-network.github.io/,
17486 Yggdrasil network}, an early-stage implementation of a fully end-to-end
17487 encrypted IPv6 network.
17490 Yggdrasil provides name-independent routing with cryptographically generated
17491 addresses. Static addressing means you can keep the same address as long as
17492 you want, even if you move to a new location, or generate a new address (by
17493 generating new keys) whenever you want.
17494 @uref{https://yggdrasil-network.github.io/2018/07/28/addressing.html}
17497 Pass it a value of @code{yggdrasil-configuration} to connect it to public
17498 peers and/or local peers.
17500 Here is an example using public peers and a static address. The static
17501 signing and encryption keys are defined in @file{/etc/yggdrasil-private.conf}
17502 (the default value for @code{config-file}).
17505 ;; part of the operating-system declaration
17506 (service yggdrasil-service-type
17507 (yggdrasil-configuration
17508 (autoconf? #f) ;; use only the public peers
17511 ;; https://github.com/yggdrasil-network/public-peers
17512 '((peers . #("tcp://1.2.3.4:1337"))))
17513 ;; /etc/yggdrasil-private.conf is the default value for config-file
17517 # sample content for /etc/yggdrasil-private.conf
17519 # Your public encryption key. Your peers may ask you for this to put
17520 # into their AllowedEncryptionPublicKeys configuration.
17521 EncryptionPublicKey: 378dc5...
17523 # Your private encryption key. DO NOT share this with anyone!
17524 EncryptionPrivateKey: 0777...
17526 # Your public signing key. You should not ordinarily need to share
17527 # this with anyone.
17528 SigningPublicKey: e1664...
17530 # Your private signing key. DO NOT share this with anyone!
17531 SigningPrivateKey: 0589d...
17536 @deftp {Data Type} yggdrasil-configuration
17537 Data type representing the configuration of Yggdrasil.
17540 @item @code{package} (default: @code{yggdrasil})
17541 Package object of Yggdrasil.
17543 @item @code{json-config} (default: @code{'()})
17544 Contents of @file{/etc/yggdrasil.conf}. Will be merged with
17545 @file{/etc/yggdrasil-private.conf}. Note that these settings are stored in
17546 the Guix store, which is readable to all users. @strong{Do not store your
17547 private keys in it}. See the output of @code{yggdrasil -genconf} for a
17548 quick overview of valid keys and their default values.
17550 @item @code{autoconf?} (default: @code{#f})
17551 Whether to use automatic mode. Enabling it makes Yggdrasil use adynamic IP
17552 and peer with IPv6 neighbors.
17554 @item @code{log-level} (default: @code{'info})
17555 How much detail to include in logs. Use @code{'debug} for more detail.
17557 @item @code{log-to} (default: @code{'stdout})
17558 Where to send logs. By default, the service logs standard output to
17559 @file{/var/log/yggdrasil.log}. The alternative is @code{'syslog}, which
17560 sends output to the running syslog service.
17562 @item @code{config-file} (default: @code{"/etc/yggdrasil-private.conf"})
17563 What HJSON file to load sensitive data from. This is where private keys
17564 should be stored, which are necessary to specify if you don't want a
17565 randomized address after each restart. Use @code{#f} to disable. Options
17566 defined in this file take precedence over @code{json-config}. Use the output
17567 of @code{yggdrasil -genconf} as a starting point. To configure a static
17568 address, delete everything except these options:
17571 @item @code{EncryptionPublicKey}
17572 @item @code{EncryptionPrivateKey}
17573 @item @code{SigningPublicKey}
17574 @item @code{SigningPrivateKey}
17580 @defvr {Scheme Variable} ipfs-service-type
17581 The service type for connecting to the @uref{https://ipfs.io,IPFS network},
17582 a global, versioned, peer-to-peer file system. Pass it a
17583 @code{ipfs-configuration} to change the ports used for the gateway and API.
17585 Here's an example configuration, using some non-standard ports:
17588 (service ipfs-service-type
17589 (ipfs-configuration
17590 (gateway "/ip4/127.0.0.1/tcp/8880")
17591 (api "/ip4/127.0.0.1/tcp/8881")))
17595 @deftp {Data Type} ipfs-configuration
17596 Data type representing the configuration of IPFS.
17599 @item @code{package} (default: @code{go-ipfs})
17600 Package object of IPFS.
17602 @item @code{gateway} (default: @code{"/ip4/127.0.0.1/tcp/8082"})
17603 Address of the gateway, in ‘multiaddress’ format.
17605 @item @code{api} (default: @code{"/ip4/127.0.0.1/tcp/5001"})
17606 Address of the API endpoint, in ‘multiaddress’ format.
17611 @deffn {Scheme Variable} keepalived-service-type
17612 This is the type for the @uref{https://www.keepalived.org/, Keepalived}
17613 routing software, @command{keepalived}. Its value must be an
17614 @code{keepalived-configuration} record as in this example for master
17618 (service keepalived-service-type
17619 (keepalived-configuration
17620 (config-file (local-file "keepalived-master.conf"))))
17623 where @file{keepalived-master.conf}:
17626 vrrp_instance my-group @{
17629 virtual_router_id 100
17631 unicast_peer @{ 10.0.0.2 @}
17632 virtual_ipaddress @{
17638 and for backup machine:
17641 (service keepalived-service-type
17642 (keepalived-configuration
17643 (config-file (local-file "keepalived-backup.conf"))))
17646 where @file{keepalived-backup.conf}:
17649 vrrp_instance my-group @{
17652 virtual_router_id 100
17654 unicast_peer @{ 10.0.0.3 @}
17655 virtual_ipaddress @{
17662 @node Unattended Upgrades
17663 @subsection Unattended Upgrades
17665 @cindex unattended upgrades
17666 @cindex upgrades, unattended
17667 Guix provides a service to perform @emph{unattended upgrades}:
17668 periodically, the system automatically reconfigures itself from the
17669 latest Guix. Guix System has several properties that make unattended
17674 upgrades are transactional (either the upgrade succeeds or it fails, but
17675 you cannot end up with an ``in-between'' system state);
17677 the upgrade log is kept---you can view it with @command{guix system
17678 list-generations}---and you can roll back to any previous generation,
17679 should the upgraded system fail to behave as intended;
17681 channel code is authenticated so you know you can only run genuine code
17682 (@pxref{Channels});
17684 @command{guix system reconfigure} prevents downgrades, which makes it
17685 immune to @dfn{downgrade attacks}.
17688 To set up unattended upgrades, add an instance of
17689 @code{unattended-upgrade-service-type} like the one below to the list of
17690 your operating system services:
17693 (service unattended-upgrade-service-type)
17696 The defaults above set up weekly upgrades: every Sunday at midnight.
17697 You do not need to provide the operating system configuration file: it
17698 uses @file{/run/current-system/configuration.scm}, which ensures it
17699 always uses your latest configuration---@pxref{provenance-service-type},
17700 for more information about this file.
17702 There are several things that can be configured, in particular the
17703 periodicity and services (daemons) to be restarted upon completion.
17704 When the upgrade is successful, the service takes care of deleting
17705 system generations older that some threshold, as per @command{guix
17706 system delete-generations}. See the reference below for details.
17708 To ensure that upgrades are actually happening, you can run
17709 @command{guix system describe}. To investigate upgrade failures, visit
17710 the unattended upgrade log file (see below).
17712 @defvr {Scheme Variable} unattended-upgrade-service-type
17713 This is the service type for unattended upgrades. It sets up an mcron
17714 job (@pxref{Scheduled Job Execution}) that runs @command{guix system
17715 reconfigure} from the latest version of the specified channels.
17717 Its value must be a @code{unattended-upgrade-configuration} record (see
17721 @deftp {Data Type} unattended-upgrade-configuration
17722 This data type represents the configuration of the unattended upgrade
17723 service. The following fields are available:
17726 @item @code{schedule} (default: @code{"30 01 * * 0"})
17727 This is the schedule of upgrades, expressed as a gexp containing an
17728 mcron job schedule (@pxref{Guile Syntax, mcron job specifications,,
17729 mcron, GNU@tie{}mcron}).
17731 @item @code{channels} (default: @code{#~%default-channels})
17732 This gexp specifies the channels to use for the upgrade
17733 (@pxref{Channels}). By default, the tip of the official @code{guix}
17736 @item @code{operating-system-file} (default: @code{"/run/current-system/configuration.scm"})
17737 This field specifies the operating system configuration file to use.
17738 The default is to reuse the config file of the current configuration.
17740 There are cases, though, where referring to
17741 @file{/run/current-system/configuration.scm} is not enough, for instance
17742 because that file refers to extra files (SSH public keys, extra
17743 configuration files, etc.) @i{via} @code{local-file} and similar
17744 constructs. For those cases, we recommend something along these lines:
17747 (unattended-upgrade-configuration
17748 (operating-system-file
17749 (file-append (local-file "." "config-dir" #:recursive? #t)
17753 The effect here is to import all of the current directory into the
17754 store, and to refer to @file{config.scm} within that directory.
17755 Therefore, uses of @code{local-file} within @file{config.scm} will work
17756 as expected. @xref{G-Expressions}, for information about
17757 @code{local-file} and @code{file-append}.
17759 @item @code{services-to-restart} (default: @code{'(mcron)})
17760 This field specifies the Shepherd services to restart when the upgrade
17763 Those services are restarted right away upon completion, as with
17764 @command{herd restart}, which ensures that the latest version is
17765 running---remember that by default @command{guix system reconfigure}
17766 only restarts services that are not currently running, which is
17767 conservative: it minimizes disruption but leaves outdated services
17770 Use @command{herd status} to find out candidates for restarting.
17771 @xref{Services}, for general information about services. Common
17772 services to restart would include @code{ntpd} and @code{ssh-daemon}.
17774 By default, the @code{mcron} service is restarted. This ensures that
17775 the latest version of the unattended upgrade job will be used next time.
17777 @item @code{system-expiration} (default: @code{(* 3 30 24 3600)})
17778 This is the expiration time in seconds for system generations. System
17779 generations older that this amount of time are deleted with
17780 @command{guix system delete-generations} when an upgrade completes.
17783 The unattended upgrade service does not run the garbage collector. You
17784 will probably want to set up your own mcron job to run @command{guix gc}
17788 @item @code{maximum-duration} (default: @code{3600})
17789 Maximum duration in seconds for the upgrade; past that time, the upgrade
17792 This is primarily useful to ensure the upgrade does not end up
17793 rebuilding or re-downloading ``the world''.
17795 @item @code{log-file} (default: @code{"/var/log/unattended-upgrade.log"})
17796 File where unattended upgrades are logged.
17801 @subsection X Window
17804 @cindex X Window System
17805 @cindex login manager
17806 Support for the X Window graphical display system---specifically
17807 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
17808 there is no @code{xorg-service} procedure. Instead, the X server is
17809 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
17812 @cindex GNOME, login manager
17813 GDM of course allows users to log in into window managers and desktop
17814 environments other than GNOME; for those using GNOME, GDM is required for
17815 features such as automatic screen locking.
17817 @cindex window manager
17818 To use X11, you must install at least one @dfn{window manager}---for
17819 example the @code{windowmaker} or @code{openbox} packages---preferably
17820 by adding it to the @code{packages} field of your operating system
17821 definition (@pxref{operating-system Reference, system-wide packages}).
17823 @defvr {Scheme Variable} gdm-service-type
17824 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
17825 Desktop Manager} (GDM), a program that manages graphical display servers and
17826 handles graphical user logins. Its value must be a @code{gdm-configuration}
17829 @cindex session types (X11)
17830 @cindex X11 session types
17831 GDM looks for @dfn{session types} described by the @file{.desktop} files in
17832 @file{/run/current-system/profile/share/xsessions} and allows users to choose
17833 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
17834 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
17835 set of packages automatically makes them available at the log-in screen.
17837 In addition, @file{~/.xsession} files are honored. When available,
17838 @file{~/.xsession} must be an executable that starts a window manager
17839 and/or other X clients.
17842 @deftp {Data Type} gdm-configuration
17844 @item @code{auto-login?} (default: @code{#f})
17845 @itemx @code{default-user} (default: @code{#f})
17846 When @code{auto-login?} is false, GDM presents a log-in screen.
17848 When @code{auto-login?} is true, GDM logs in directly as
17849 @code{default-user}.
17851 @item @code{debug?} (default: @code{#f})
17852 When true, GDM writes debug messages to its log.
17854 @item @code{gnome-shell-assets} (default: ...)
17855 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
17857 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
17858 Configuration of the Xorg graphical server.
17860 @item @code{xsession} (default: @code{(xinitrc)})
17861 Script to run before starting a X session.
17863 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
17864 File name of the @code{dbus-daemon} executable.
17866 @item @code{gdm} (default: @code{gdm})
17867 The GDM package to use.
17871 @defvr {Scheme Variable} slim-service-type
17872 This is the type for the SLiM graphical login manager for X11.
17874 Like GDM, SLiM looks for session types described by @file{.desktop} files and
17875 allows users to choose a session from the log-in screen using @kbd{F1}. It
17876 also honors @file{~/.xsession} files.
17878 Unlike GDM, SLiM does not spawn the user session on a different VT after
17879 logging in, which means that you can only start one graphical session. If you
17880 want to be able to run multiple graphical sessions at the same time you have
17881 to add multiple SLiM services to your system services. The following example
17882 shows how to replace the default GDM service with two SLiM services on tty7
17886 (use-modules (gnu services)
17887 (gnu services desktop)
17888 (gnu services xorg)
17889 (srfi srfi-1)) ;for 'remove'
17893 (services (cons* (service slim-service-type (slim-configuration
17896 (service slim-service-type (slim-configuration
17899 (modify-services %desktop-services
17900 (delete gdm-service-type)))))
17905 @deftp {Data Type} slim-configuration
17906 Data type representing the configuration of @code{slim-service-type}.
17909 @item @code{allow-empty-passwords?} (default: @code{#t})
17910 Whether to allow logins with empty passwords.
17912 @item @code{auto-login?} (default: @code{#f})
17913 @itemx @code{default-user} (default: @code{""})
17914 When @code{auto-login?} is false, SLiM presents a log-in screen.
17916 When @code{auto-login?} is true, SLiM logs in directly as
17917 @code{default-user}.
17919 @item @code{theme} (default: @code{%default-slim-theme})
17920 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
17921 The graphical theme to use and its name.
17923 @item @code{auto-login-session} (default: @code{#f})
17924 If true, this must be the name of the executable to start as the default
17925 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
17927 If false, a session described by one of the available @file{.desktop}
17928 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
17932 You must install at least one window manager in the system profile or in
17933 your user profile. Failing to do that, if @code{auto-login-session} is
17934 false, you will be unable to log in.
17937 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
17938 Configuration of the Xorg graphical server.
17940 @item @code{display} (default @code{":0"})
17941 The display on which to start the Xorg graphical server.
17943 @item @code{vt} (default @code{"vt7"})
17944 The VT on which to start the Xorg graphical server.
17946 @item @code{xauth} (default: @code{xauth})
17947 The XAuth package to use.
17949 @item @code{shepherd} (default: @code{shepherd})
17950 The Shepherd package used when invoking @command{halt} and
17953 @item @code{sessreg} (default: @code{sessreg})
17954 The sessreg package used in order to register the session.
17956 @item @code{slim} (default: @code{slim})
17957 The SLiM package to use.
17961 @defvr {Scheme Variable} %default-theme
17962 @defvrx {Scheme Variable} %default-theme-name
17963 The default SLiM theme and its name.
17967 @deftp {Data Type} sddm-configuration
17968 This is the data type representing the SDDM service configuration.
17971 @item @code{display-server} (default: "x11")
17972 Select display server to use for the greeter. Valid values are
17973 @samp{"x11"} or @samp{"wayland"}.
17975 @item @code{numlock} (default: "on")
17976 Valid values are @samp{"on"}, @samp{"off"} or @samp{"none"}.
17978 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
17979 Command to run when halting.
17981 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
17982 Command to run when rebooting.
17984 @item @code{theme} (default "maldives")
17985 Theme to use. Default themes provided by SDDM are @samp{"elarun"},
17986 @samp{"maldives"} or @samp{"maya"}.
17988 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
17989 Directory to look for themes.
17991 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
17992 Directory to look for faces.
17994 @item @code{default-path} (default "/run/current-system/profile/bin")
17995 Default PATH to use.
17997 @item @code{minimum-uid} (default: 1000)
17998 Minimum UID displayed in SDDM and allowed for log-in.
18000 @item @code{maximum-uid} (default: 2000)
18001 Maximum UID to display in SDDM.
18003 @item @code{remember-last-user?} (default #t)
18004 Remember last user.
18006 @item @code{remember-last-session?} (default #t)
18007 Remember last session.
18009 @item @code{hide-users} (default "")
18010 Usernames to hide from SDDM greeter.
18012 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
18013 Users with shells listed will be hidden from the SDDM greeter.
18015 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
18016 Script to run before starting a wayland session.
18018 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
18019 Directory to look for desktop files starting wayland sessions.
18021 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
18022 Configuration of the Xorg graphical server.
18024 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
18027 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
18030 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
18031 Script to run after starting xorg-server.
18033 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
18034 Script to run before stopping xorg-server.
18036 @item @code{xsession-command} (default: @code{xinitrc})
18037 Script to run before starting a X session.
18039 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
18040 Directory to look for desktop files starting X sessions.
18042 @item @code{minimum-vt} (default: 7)
18045 @item @code{auto-login-user} (default "")
18046 User to use for auto-login.
18048 @item @code{auto-login-session} (default "")
18049 Desktop file to use for auto-login.
18051 @item @code{relogin?} (default #f)
18052 Relogin after logout.
18057 @cindex login manager
18059 @defvr {Scheme Variable} sddm-service-type
18060 This is the type of the service to run the
18061 @uref{https://github.com/sddm/sddm,SDDM display manager}. Its value
18062 must be a @code{sddm-configuration} record (see below).
18064 Here's an example use:
18067 (service sddm-service-type
18068 (sddm-configuration
18069 (auto-login-user "alice")
18070 (auto-login-session "xfce.desktop")))
18074 @deftp {Data Type} sddm-configuration
18075 This data type represents the configuration of the SDDM login manager.
18076 The available fields are:
18079 @item @code{sddm} (default: @code{sddm})
18080 The SDDM package to use.
18082 @item @code{display-server} (default: @code{"x11"})
18083 This must be either @code{"x11"} or @code{"wayland"}.
18085 @c FIXME: Add more fields.
18087 @item @code{auto-login-user} (default: @code{""})
18088 If non-empty, this is the user account under which to log in
18091 @item @code{auto-login-session} (default: @code{""})
18092 If non-empty, this is the @file{.desktop} file name to use as the
18093 auto-login session.
18097 @cindex Xorg, configuration
18098 @deftp {Data Type} xorg-configuration
18099 This data type represents the configuration of the Xorg graphical display
18100 server. Note that there is no Xorg service; instead, the X server is started
18101 by a ``display manager'' such as GDM, SDDM, and SLiM@. Thus, the configuration
18102 of these display managers aggregates an @code{xorg-configuration} record.
18105 @item @code{modules} (default: @code{%default-xorg-modules})
18106 This is a list of @dfn{module packages} loaded by the Xorg
18107 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
18109 @item @code{fonts} (default: @code{%default-xorg-fonts})
18110 This is a list of font directories to add to the server's @dfn{font path}.
18112 @item @code{drivers} (default: @code{'()})
18113 This must be either the empty list, in which case Xorg chooses a graphics
18114 driver automatically, or a list of driver names that will be tried in this
18115 order---e.g., @code{("modesetting" "vesa")}.
18117 @item @code{resolutions} (default: @code{'()})
18118 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
18119 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
18122 @cindex keyboard layout, for Xorg
18123 @cindex keymap, for Xorg
18124 @item @code{keyboard-layout} (default: @code{#f})
18125 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
18126 English (``qwerty'') for a 105-key PC keyboard.
18128 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
18129 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
18130 information on how to specify the keyboard layout.
18132 @item @code{extra-config} (default: @code{'()})
18133 This is a list of strings or objects appended to the configuration file. It
18134 is used to pass extra text to be added verbatim to the configuration file.
18136 @item @code{server} (default: @code{xorg-server})
18137 This is the package providing the Xorg server.
18139 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
18140 This is the list of command-line arguments to pass to the X server. The
18141 default is @code{-nolisten tcp}.
18145 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
18146 [@var{login-manager-service-type}]
18147 Tell the log-in manager (of type @var{login-manager-service-type}) to use
18148 @var{config}, an @code{<xorg-configuration>} record.
18150 Since the Xorg configuration is embedded in the log-in manager's
18151 configuration---e.g., @code{gdm-configuration}---this procedure provides a
18152 shorthand to set the Xorg configuration.
18155 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
18156 Return a @code{startx} script in which the modules, fonts, etc. specified
18157 in @var{config}, are available. The result should be used in place of
18160 Usually the X server is started by a login manager.
18164 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
18165 Add @var{package}, a package for a screen locker or screen saver whose
18166 command is @var{program}, to the set of setuid programs and add a PAM entry
18167 for it. For example:
18170 (screen-locker-service xlockmore "xlock")
18173 makes the good ol' XlockMore usable.
18177 @node Printing Services
18178 @subsection Printing Services
18180 @cindex printer support with CUPS
18181 The @code{(gnu services cups)} module provides a Guix service definition
18182 for the CUPS printing service. To add printer support to a Guix
18183 system, add a @code{cups-service} to the operating system definition:
18185 @deffn {Scheme Variable} cups-service-type
18186 The service type for the CUPS print server. Its value should be a valid
18187 CUPS configuration (see below). To use the default settings, simply
18190 (service cups-service-type)
18194 The CUPS configuration controls the basic things about your CUPS
18195 installation: what interfaces it listens on, what to do if a print job
18196 fails, how much logging to do, and so on. To actually add a printer,
18197 you have to visit the @url{http://localhost:631} URL, or use a tool such
18198 as GNOME's printer configuration services. By default, configuring a
18199 CUPS service will generate a self-signed certificate if needed, for
18200 secure connections to the print server.
18202 Suppose you want to enable the Web interface of CUPS and also add
18203 support for Epson printers @i{via} the @code{epson-inkjet-printer-escpr}
18204 package and for HP printers @i{via} the @code{hplip-minimal} package.
18205 You can do that directly, like this (you need to use the
18206 @code{(gnu packages cups)} module):
18209 (service cups-service-type
18210 (cups-configuration
18211 (web-interface? #t)
18213 (list cups-filters epson-inkjet-printer-escpr hplip-minimal))))
18216 Note: If you wish to use the Qt5 based GUI which comes with the hplip
18217 package then it is suggested that you install the @code{hplip} package,
18218 either in your OS configuration file or as your user.
18220 The available configuration parameters follow. Each parameter
18221 definition is preceded by its type; for example, @samp{string-list foo}
18222 indicates that the @code{foo} parameter should be specified as a list of
18223 strings. There is also a way to specify the configuration as a string,
18224 if you have an old @code{cupsd.conf} file that you want to port over
18225 from some other system; see the end for more details.
18227 @c The following documentation was initially generated by
18228 @c (generate-documentation) in (gnu services cups). Manually maintained
18229 @c documentation is better, so we shouldn't hesitate to edit below as
18230 @c needed. However if the change you want to make to this documentation
18231 @c can be done in an automated way, it's probably easier to change
18232 @c (generate-documentation) than to make it below and have to deal with
18233 @c the churn as CUPS updates.
18236 Available @code{cups-configuration} fields are:
18238 @deftypevr {@code{cups-configuration} parameter} package cups
18242 @deftypevr {@code{cups-configuration} parameter} package-list extensions (default: @code{(list brlaser cups-filters epson-inkjet-printer-escpr foomatic-filters hplip-minimal splix)})
18243 Drivers and other extensions to the CUPS package.
18246 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
18247 Configuration of where to write logs, what directories to use for print
18248 spools, and related privileged configuration parameters.
18250 Available @code{files-configuration} fields are:
18252 @deftypevr {@code{files-configuration} parameter} log-location access-log
18253 Defines the access log filename. Specifying a blank filename disables
18254 access log generation. The value @code{stderr} causes log entries to be
18255 sent to the standard error file when the scheduler is running in the
18256 foreground, or to the system log daemon when run in the background. The
18257 value @code{syslog} causes log entries to be sent to the system log
18258 daemon. The server name may be included in filenames using the string
18259 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
18261 Defaults to @samp{"/var/log/cups/access_log"}.
18264 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
18265 Where CUPS should cache data.
18267 Defaults to @samp{"/var/cache/cups"}.
18270 @deftypevr {@code{files-configuration} parameter} string config-file-perm
18271 Specifies the permissions for all configuration files that the scheduler
18274 Note that the permissions for the printers.conf file are currently
18275 masked to only allow access from the scheduler user (typically root).
18276 This is done because printer device URIs sometimes contain sensitive
18277 authentication information that should not be generally known on the
18278 system. There is no way to disable this security feature.
18280 Defaults to @samp{"0640"}.
18283 @deftypevr {@code{files-configuration} parameter} log-location error-log
18284 Defines the error log filename. Specifying a blank filename disables
18285 error log generation. The value @code{stderr} causes log entries to be
18286 sent to the standard error file when the scheduler is running in the
18287 foreground, or to the system log daemon when run in the background. The
18288 value @code{syslog} causes log entries to be sent to the system log
18289 daemon. The server name may be included in filenames using the string
18290 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
18292 Defaults to @samp{"/var/log/cups/error_log"}.
18295 @deftypevr {@code{files-configuration} parameter} string fatal-errors
18296 Specifies which errors are fatal, causing the scheduler to exit. The
18301 No errors are fatal.
18304 All of the errors below are fatal.
18307 Browsing initialization errors are fatal, for example failed connections
18308 to the DNS-SD daemon.
18311 Configuration file syntax errors are fatal.
18314 Listen or Port errors are fatal, except for IPv6 failures on the
18315 loopback or @code{any} addresses.
18318 Log file creation or write errors are fatal.
18321 Bad startup file permissions are fatal, for example shared TLS
18322 certificate and key files with world-read permissions.
18325 Defaults to @samp{"all -browse"}.
18328 @deftypevr {@code{files-configuration} parameter} boolean file-device?
18329 Specifies whether the file pseudo-device can be used for new printer
18330 queues. The URI @uref{file:///dev/null} is always allowed.
18332 Defaults to @samp{#f}.
18335 @deftypevr {@code{files-configuration} parameter} string group
18336 Specifies the group name or ID that will be used when executing external
18339 Defaults to @samp{"lp"}.
18342 @deftypevr {@code{files-configuration} parameter} string log-file-perm
18343 Specifies the permissions for all log files that the scheduler writes.
18345 Defaults to @samp{"0644"}.
18348 @deftypevr {@code{files-configuration} parameter} log-location page-log
18349 Defines the page log filename. Specifying a blank filename disables
18350 page log generation. The value @code{stderr} causes log entries to be
18351 sent to the standard error file when the scheduler is running in the
18352 foreground, or to the system log daemon when run in the background. The
18353 value @code{syslog} causes log entries to be sent to the system log
18354 daemon. The server name may be included in filenames using the string
18355 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
18357 Defaults to @samp{"/var/log/cups/page_log"}.
18360 @deftypevr {@code{files-configuration} parameter} string remote-root
18361 Specifies the username that is associated with unauthenticated accesses
18362 by clients claiming to be the root user. The default is @code{remroot}.
18364 Defaults to @samp{"remroot"}.
18367 @deftypevr {@code{files-configuration} parameter} file-name request-root
18368 Specifies the directory that contains print jobs and other HTTP request
18371 Defaults to @samp{"/var/spool/cups"}.
18374 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
18375 Specifies the level of security sandboxing that is applied to print
18376 filters, backends, and other child processes of the scheduler; either
18377 @code{relaxed} or @code{strict}. This directive is currently only
18378 used/supported on macOS.
18380 Defaults to @samp{strict}.
18383 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
18384 Specifies the location of TLS certificates and private keys. CUPS will
18385 look for public and private keys in this directory: @file{.crt} files
18386 for PEM-encoded certificates and corresponding @file{.key} files for
18387 PEM-encoded private keys.
18389 Defaults to @samp{"/etc/cups/ssl"}.
18392 @deftypevr {@code{files-configuration} parameter} file-name server-root
18393 Specifies the directory containing the server configuration files.
18395 Defaults to @samp{"/etc/cups"}.
18398 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
18399 Specifies whether the scheduler calls fsync(2) after writing
18400 configuration or state files.
18402 Defaults to @samp{#f}.
18405 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
18406 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
18409 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
18410 Specifies the directory where temporary files are stored.
18412 Defaults to @samp{"/var/spool/cups/tmp"}.
18415 @deftypevr {@code{files-configuration} parameter} string user
18416 Specifies the user name or ID that is used when running external
18419 Defaults to @samp{"lp"}.
18422 @deftypevr {@code{files-configuration} parameter} string set-env
18423 Set the specified environment variable to be passed to child processes.
18425 Defaults to @samp{"variable value"}.
18429 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
18430 Specifies the logging level for the AccessLog file. The @code{config}
18431 level logs when printers and classes are added, deleted, or modified and
18432 when configuration files are accessed or updated. The @code{actions}
18433 level logs when print jobs are submitted, held, released, modified, or
18434 canceled, and any of the conditions for @code{config}. The @code{all}
18435 level logs all requests.
18437 Defaults to @samp{actions}.
18440 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
18441 Specifies whether to purge job history data automatically when it is no
18442 longer required for quotas.
18444 Defaults to @samp{#f}.
18447 @deftypevr {@code{cups-configuration} parameter} comma-separated-string-list browse-dns-sd-sub-types
18448 Specifies a list of DNS-SD sub-types to advertise for each shared printer.
18449 For example, @samp{"_cups" "_print"} will tell network clients that both
18450 CUPS sharing and IPP Everywhere are supported.
18452 Defaults to @samp{"_cups"}.
18455 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
18456 Specifies which protocols to use for local printer sharing.
18458 Defaults to @samp{dnssd}.
18461 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
18462 Specifies whether the CUPS web interface is advertised.
18464 Defaults to @samp{#f}.
18467 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
18468 Specifies whether shared printers are advertised.
18470 Defaults to @samp{#f}.
18473 @deftypevr {@code{cups-configuration} parameter} string classification
18474 Specifies the security classification of the server. Any valid banner
18475 name can be used, including @samp{"classified"}, @samp{"confidential"},
18476 @samp{"secret"}, @samp{"topsecret"}, and @samp{"unclassified"}, or the
18477 banner can be omitted to disable secure printing functions.
18479 Defaults to @samp{""}.
18482 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
18483 Specifies whether users may override the classification (cover page) of
18484 individual print jobs using the @code{job-sheets} option.
18486 Defaults to @samp{#f}.
18489 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
18490 Specifies the default type of authentication to use.
18492 Defaults to @samp{Basic}.
18495 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
18496 Specifies whether encryption will be used for authenticated requests.
18498 Defaults to @samp{Required}.
18501 @deftypevr {@code{cups-configuration} parameter} string default-language
18502 Specifies the default language to use for text and web content.
18504 Defaults to @samp{"en"}.
18507 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
18508 Specifies the default paper size for new print queues. @samp{"Auto"}
18509 uses a locale-specific default, while @samp{"None"} specifies there is
18510 no default paper size. Specific size names are typically
18511 @samp{"Letter"} or @samp{"A4"}.
18513 Defaults to @samp{"Auto"}.
18516 @deftypevr {@code{cups-configuration} parameter} string default-policy
18517 Specifies the default access policy to use.
18519 Defaults to @samp{"default"}.
18522 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
18523 Specifies whether local printers are shared by default.
18525 Defaults to @samp{#t}.
18528 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
18529 Specifies the delay for updating of configuration and state files, in
18530 seconds. A value of 0 causes the update to happen as soon as possible,
18531 typically within a few milliseconds.
18533 Defaults to @samp{30}.
18536 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
18537 Specifies what to do when an error occurs. Possible values are
18538 @code{abort-job}, which will discard the failed print job;
18539 @code{retry-job}, which will retry the job at a later time;
18540 @code{retry-current-job}, which retries the failed job immediately; and
18541 @code{stop-printer}, which stops the printer.
18543 Defaults to @samp{stop-printer}.
18546 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
18547 Specifies the maximum cost of filters that are run concurrently, which
18548 can be used to minimize disk, memory, and CPU resource problems. A
18549 limit of 0 disables filter limiting. An average print to a
18550 non-PostScript printer needs a filter limit of about 200. A PostScript
18551 printer needs about half that (100). Setting the limit below these
18552 thresholds will effectively limit the scheduler to printing a single job
18555 Defaults to @samp{0}.
18558 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
18559 Specifies the scheduling priority of filters that are run to print a
18560 job. The nice value ranges from 0, the highest priority, to 19, the
18563 Defaults to @samp{0}.
18566 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
18567 Specifies whether to do reverse lookups on connecting clients. The
18568 @code{double} setting causes @code{cupsd} to verify that the hostname
18569 resolved from the address matches one of the addresses returned for that
18570 hostname. Double lookups also prevent clients with unregistered
18571 addresses from connecting to your server. Only set this option to
18572 @code{#t} or @code{double} if absolutely required.
18574 Defaults to @samp{#f}.
18577 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
18578 Specifies the number of seconds to wait before killing the filters and
18579 backend associated with a canceled or held job.
18581 Defaults to @samp{30}.
18584 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
18585 Specifies the interval between retries of jobs in seconds. This is
18586 typically used for fax queues but can also be used with normal print
18587 queues whose error policy is @code{retry-job} or
18588 @code{retry-current-job}.
18590 Defaults to @samp{30}.
18593 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
18594 Specifies the number of retries that are done for jobs. This is
18595 typically used for fax queues but can also be used with normal print
18596 queues whose error policy is @code{retry-job} or
18597 @code{retry-current-job}.
18599 Defaults to @samp{5}.
18602 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
18603 Specifies whether to support HTTP keep-alive connections.
18605 Defaults to @samp{#t}.
18608 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
18609 Specifies how long an idle client connection remains open, in seconds.
18611 Defaults to @samp{30}.
18614 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
18615 Specifies the maximum size of print files, IPP requests, and HTML form
18616 data. A limit of 0 disables the limit check.
18618 Defaults to @samp{0}.
18621 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
18622 Listens on the specified interfaces for connections. Valid values are
18623 of the form @var{address}:@var{port}, where @var{address} is either an
18624 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
18625 indicate all addresses. Values can also be file names of local UNIX
18626 domain sockets. The Listen directive is similar to the Port directive
18627 but allows you to restrict access to specific interfaces or networks.
18630 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
18631 Specifies the number of pending connections that will be allowed. This
18632 normally only affects very busy servers that have reached the MaxClients
18633 limit, but can also be triggered by large numbers of simultaneous
18634 connections. When the limit is reached, the operating system will
18635 refuse additional connections until the scheduler can accept the pending
18638 Defaults to @samp{128}.
18641 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
18642 Specifies a set of additional access controls.
18644 Available @code{location-access-controls} fields are:
18646 @deftypevr {@code{location-access-controls} parameter} file-name path
18647 Specifies the URI path to which the access control applies.
18650 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
18651 Access controls for all access to this path, in the same format as the
18652 @code{access-controls} of @code{operation-access-control}.
18654 Defaults to @samp{()}.
18657 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
18658 Access controls for method-specific access to this path.
18660 Defaults to @samp{()}.
18662 Available @code{method-access-controls} fields are:
18664 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
18665 If @code{#t}, apply access controls to all methods except the listed
18666 methods. Otherwise apply to only the listed methods.
18668 Defaults to @samp{#f}.
18671 @deftypevr {@code{method-access-controls} parameter} method-list methods
18672 Methods to which this access control applies.
18674 Defaults to @samp{()}.
18677 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
18678 Access control directives, as a list of strings. Each string should be
18679 one directive, such as @samp{"Order allow,deny"}.
18681 Defaults to @samp{()}.
18686 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
18687 Specifies the number of debugging messages that are retained for logging
18688 if an error occurs in a print job. Debug messages are logged regardless
18689 of the LogLevel setting.
18691 Defaults to @samp{100}.
18694 @deftypevr {@code{cups-configuration} parameter} log-level log-level
18695 Specifies the level of logging for the ErrorLog file. The value
18696 @code{none} stops all logging while @code{debug2} logs everything.
18698 Defaults to @samp{info}.
18701 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
18702 Specifies the format of the date and time in the log files. The value
18703 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
18705 Defaults to @samp{standard}.
18708 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
18709 Specifies the maximum number of simultaneous clients that are allowed by
18712 Defaults to @samp{100}.
18715 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
18716 Specifies the maximum number of simultaneous clients that are allowed
18717 from a single address.
18719 Defaults to @samp{100}.
18722 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
18723 Specifies the maximum number of copies that a user can print of each
18726 Defaults to @samp{9999}.
18729 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
18730 Specifies the maximum time a job may remain in the @code{indefinite}
18731 hold state before it is canceled. A value of 0 disables cancellation of
18734 Defaults to @samp{0}.
18737 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
18738 Specifies the maximum number of simultaneous jobs that are allowed. Set
18739 to 0 to allow an unlimited number of jobs.
18741 Defaults to @samp{500}.
18744 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
18745 Specifies the maximum number of simultaneous jobs that are allowed per
18746 printer. A value of 0 allows up to MaxJobs jobs per printer.
18748 Defaults to @samp{0}.
18751 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
18752 Specifies the maximum number of simultaneous jobs that are allowed per
18753 user. A value of 0 allows up to MaxJobs jobs per user.
18755 Defaults to @samp{0}.
18758 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
18759 Specifies the maximum time a job may take to print before it is
18760 canceled, in seconds. Set to 0 to disable cancellation of ``stuck'' jobs.
18762 Defaults to @samp{10800}.
18765 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
18766 Specifies the maximum size of the log files before they are rotated, in
18767 bytes. The value 0 disables log rotation.
18769 Defaults to @samp{1048576}.
18772 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
18773 Specifies the maximum amount of time to allow between files in a
18774 multiple file print job, in seconds.
18776 Defaults to @samp{300}.
18779 @deftypevr {@code{cups-configuration} parameter} string page-log-format
18780 Specifies the format of PageLog lines. Sequences beginning with percent
18781 (@samp{%}) characters are replaced with the corresponding information,
18782 while all other characters are copied literally. The following percent
18783 sequences are recognized:
18787 insert a single percent character
18790 insert the value of the specified IPP attribute
18793 insert the number of copies for the current page
18796 insert the current page number
18799 insert the current date and time in common log format
18805 insert the printer name
18808 insert the username
18811 A value of the empty string disables page logging. The string @code{%p
18812 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
18813 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
18816 Defaults to @samp{""}.
18819 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
18820 Passes the specified environment variable(s) to child processes; a list
18823 Defaults to @samp{()}.
18826 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
18827 Specifies named access control policies.
18829 Available @code{policy-configuration} fields are:
18831 @deftypevr {@code{policy-configuration} parameter} string name
18832 Name of the policy.
18835 @deftypevr {@code{policy-configuration} parameter} string job-private-access
18836 Specifies an access list for a job's private values. @code{@@ACL} maps
18837 to the printer's requesting-user-name-allowed or
18838 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
18839 owner. @code{@@SYSTEM} maps to the groups listed for the
18840 @code{system-group} field of the @code{files-config} configuration,
18841 which is reified into the @code{cups-files.conf(5)} file. Other
18842 possible elements of the access list include specific user names, and
18843 @code{@@@var{group}} to indicate members of a specific group. The
18844 access list may also be simply @code{all} or @code{default}.
18846 Defaults to @samp{"@@OWNER @@SYSTEM"}.
18849 @deftypevr {@code{policy-configuration} parameter} string job-private-values
18850 Specifies the list of job values to make private, or @code{all},
18851 @code{default}, or @code{none}.
18853 Defaults to @samp{"job-name job-originating-host-name
18854 job-originating-user-name phone"}.
18857 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
18858 Specifies an access list for a subscription's private values.
18859 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
18860 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
18861 owner. @code{@@SYSTEM} maps to the groups listed for the
18862 @code{system-group} field of the @code{files-config} configuration,
18863 which is reified into the @code{cups-files.conf(5)} file. Other
18864 possible elements of the access list include specific user names, and
18865 @code{@@@var{group}} to indicate members of a specific group. The
18866 access list may also be simply @code{all} or @code{default}.
18868 Defaults to @samp{"@@OWNER @@SYSTEM"}.
18871 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
18872 Specifies the list of job values to make private, or @code{all},
18873 @code{default}, or @code{none}.
18875 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
18876 notify-subscriber-user-name notify-user-data"}.
18879 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
18880 Access control by IPP operation.
18882 Defaults to @samp{()}.
18886 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
18887 Specifies whether job files (documents) are preserved after a job is
18888 printed. If a numeric value is specified, job files are preserved for
18889 the indicated number of seconds after printing. Otherwise a boolean
18890 value applies indefinitely.
18892 Defaults to @samp{86400}.
18895 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
18896 Specifies whether the job history is preserved after a job is printed.
18897 If a numeric value is specified, the job history is preserved for the
18898 indicated number of seconds after printing. If @code{#t}, the job
18899 history is preserved until the MaxJobs limit is reached.
18901 Defaults to @samp{#t}.
18904 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
18905 Specifies the amount of time to wait for job completion before
18906 restarting the scheduler.
18908 Defaults to @samp{30}.
18911 @deftypevr {@code{cups-configuration} parameter} string rip-cache
18912 Specifies the maximum amount of memory to use when converting documents
18913 into bitmaps for a printer.
18915 Defaults to @samp{"128m"}.
18918 @deftypevr {@code{cups-configuration} parameter} string server-admin
18919 Specifies the email address of the server administrator.
18921 Defaults to @samp{"root@@localhost.localdomain"}.
18924 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
18925 The ServerAlias directive is used for HTTP Host header validation when
18926 clients connect to the scheduler from external interfaces. Using the
18927 special name @code{*} can expose your system to known browser-based DNS
18928 rebinding attacks, even when accessing sites through a firewall. If the
18929 auto-discovery of alternate names does not work, we recommend listing
18930 each alternate name with a ServerAlias directive instead of using
18933 Defaults to @samp{*}.
18936 @deftypevr {@code{cups-configuration} parameter} string server-name
18937 Specifies the fully-qualified host name of the server.
18939 Defaults to @samp{"localhost"}.
18942 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
18943 Specifies what information is included in the Server header of HTTP
18944 responses. @code{None} disables the Server header. @code{ProductOnly}
18945 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
18946 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
18947 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
18948 the output of the @code{uname} command. @code{Full} reports @code{CUPS
18949 2.0.0 (@var{uname}) IPP/2.0}.
18951 Defaults to @samp{Minimal}.
18954 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
18955 Listens on the specified interfaces for encrypted connections. Valid
18956 values are of the form @var{address}:@var{port}, where @var{address} is
18957 either an IPv6 address enclosed in brackets, an IPv4 address, or
18958 @code{*} to indicate all addresses.
18960 Defaults to @samp{()}.
18963 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
18964 Sets encryption options. By default, CUPS only supports encryption
18965 using TLS v1.0 or higher using known secure cipher suites. Security is
18966 reduced when @code{Allow} options are used, and enhanced when @code{Deny}
18967 options are used. The @code{AllowRC4} option enables the 128-bit RC4 cipher
18968 suites, which are required for some older clients. The @code{AllowSSL3} option
18969 enables SSL v3.0, which is required for some older clients that do not support
18970 TLS v1.0. The @code{DenyCBC} option disables all CBC cipher suites. The
18971 @code{DenyTLS1.0} option disables TLS v1.0 support - this sets the minimum
18972 protocol version to TLS v1.1.
18974 Defaults to @samp{()}.
18977 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
18978 Specifies whether the scheduler requires clients to strictly adhere to
18979 the IPP specifications.
18981 Defaults to @samp{#f}.
18984 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
18985 Specifies the HTTP request timeout, in seconds.
18987 Defaults to @samp{300}.
18991 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
18992 Specifies whether the web interface is enabled.
18994 Defaults to @samp{#f}.
18997 At this point you're probably thinking ``oh dear, Guix manual, I like
18998 you but you can stop already with the configuration options''. Indeed.
18999 However, one more point: it could be that you have an existing
19000 @code{cupsd.conf} that you want to use. In that case, you can pass an
19001 @code{opaque-cups-configuration} as the configuration of a
19002 @code{cups-service-type}.
19004 Available @code{opaque-cups-configuration} fields are:
19006 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
19010 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
19011 The contents of the @code{cupsd.conf}, as a string.
19014 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
19015 The contents of the @code{cups-files.conf} file, as a string.
19018 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
19019 strings of the same name, you could instantiate a CUPS service like
19023 (service cups-service-type
19024 (opaque-cups-configuration
19025 (cupsd.conf cupsd.conf)
19026 (cups-files.conf cups-files.conf)))
19030 @node Desktop Services
19031 @subsection Desktop Services
19033 The @code{(gnu services desktop)} module provides services that are
19034 usually useful in the context of a ``desktop'' setup---that is, on a
19035 machine running a graphical display server, possibly with graphical user
19036 interfaces, etc. It also defines services that provide specific desktop
19037 environments like GNOME, Xfce or MATE.
19039 To simplify things, the module defines a variable containing the set of
19040 services that users typically expect on a machine with a graphical
19041 environment and networking:
19043 @defvr {Scheme Variable} %desktop-services
19044 This is a list of services that builds upon @code{%base-services} and
19045 adds or adjusts services for a typical ``desktop'' setup.
19047 In particular, it adds a graphical login manager (@pxref{X Window,
19048 @code{gdm-service-type}}), screen lockers, a network management tool
19049 (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
19050 support (@pxref{Networking Services, @code{modem-manager-service-type}}),
19051 energy and color management services, the @code{elogind} login and seat
19052 manager, the Polkit privilege service, the GeoClue location service, the
19053 AccountsService daemon that allows authorized users change system passwords,
19054 an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
19055 name service switch service configured to be able to use @code{nss-mdns}
19056 (@pxref{Name Service Switch, mDNS}).
19059 The @code{%desktop-services} variable can be used as the @code{services}
19060 field of an @code{operating-system} declaration (@pxref{operating-system
19061 Reference, @code{services}}).
19063 Additionally, the @code{gnome-desktop-service-type},
19064 @code{xfce-desktop-service}, @code{mate-desktop-service-type},
19065 @code{lxqt-desktop-service-type} and @code{enlightenment-desktop-service-type}
19066 procedures can add GNOME, Xfce, MATE and/or Enlightenment to a system. To
19067 ``add GNOME'' means that system-level services like the backlight adjustment
19068 helpers and the power management utilities are added to the system, extending
19069 @code{polkit} and @code{dbus} appropriately, allowing GNOME to operate with
19070 elevated privileges on a limited number of special-purpose system interfaces.
19071 Additionally, adding a service made by @code{gnome-desktop-service-type} adds
19072 the GNOME metapackage to the system profile. Likewise, adding the Xfce
19073 service not only adds the @code{xfce} metapackage to the system profile, but
19074 it also gives the Thunar file manager the ability to open a ``root-mode'' file
19075 management window, if the user authenticates using the administrator's
19076 password via the standard polkit graphical interface. To ``add MATE'' means
19077 that @code{polkit} and @code{dbus} are extended appropriately, allowing MATE
19078 to operate with elevated privileges on a limited number of special-purpose
19079 system interfaces. Additionally, adding a service of type
19080 @code{mate-desktop-service-type} adds the MATE metapackage to the system
19081 profile. ``Adding Enlightenment'' means that @code{dbus} is extended
19082 appropriately, and several of Enlightenment's binaries are set as setuid,
19083 allowing Enlightenment's screen locker and other functionality to work as
19086 The desktop environments in Guix use the Xorg display server by
19087 default. If you'd like to use the newer display server protocol
19088 called Wayland, you need to use the @code{sddm-service} instead of
19089 GDM as the graphical login manager. You should then
19090 select the ``GNOME (Wayland)'' session in SDDM@. Alternatively you can
19091 also try starting GNOME on Wayland manually from a TTY with the
19092 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
19093 gnome-session``. Currently only GNOME has support for Wayland.
19095 @defvr {Scheme Variable} gnome-desktop-service-type
19096 This is the type of the service that adds the @uref{https://www.gnome.org,
19097 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
19098 object (see below).
19100 This service adds the @code{gnome} package to the system profile, and extends
19101 polkit with the actions from @code{gnome-settings-daemon}.
19104 @deftp {Data Type} gnome-desktop-configuration
19105 Configuration record for the GNOME desktop environment.
19108 @item @code{gnome} (default: @code{gnome})
19109 The GNOME package to use.
19113 @defvr {Scheme Variable} xfce-desktop-service-type
19114 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
19115 desktop environment. Its value is an @code{xfce-desktop-configuration} object
19118 This service adds the @code{xfce} package to the system profile, and
19119 extends polkit with the ability for @code{thunar} to manipulate the file
19120 system as root from within a user session, after the user has authenticated
19121 with the administrator's password.
19123 Note that @code{xfce4-panel} and its plugin packages should be installed in
19124 the same profile to ensure compatibility. When using this service, you should
19125 add extra plugins (@code{xfce4-whiskermenu-plugin},
19126 @code{xfce4-weather-plugin}, etc.) to the @code{packages} field of your
19127 @code{operating-system}.
19130 @deftp {Data Type} xfce-desktop-configuration
19131 Configuration record for the Xfce desktop environment.
19134 @item @code{xfce} (default: @code{xfce})
19135 The Xfce package to use.
19139 @deffn {Scheme Variable} mate-desktop-service-type
19140 This is the type of the service that runs the @uref{https://mate-desktop.org/,
19141 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
19142 object (see below).
19144 This service adds the @code{mate} package to the system
19145 profile, and extends polkit with the actions from
19146 @code{mate-settings-daemon}.
19149 @deftp {Data Type} mate-desktop-configuration
19150 Configuration record for the MATE desktop environment.
19153 @item @code{mate} (default: @code{mate})
19154 The MATE package to use.
19158 @deffn {Scheme Variable} lxqt-desktop-service-type
19159 This is the type of the service that runs the @uref{https://lxqt.github.io,
19160 LXQt desktop environment}. Its value is a @code{lxqt-desktop-configuration}
19161 object (see below).
19163 This service adds the @code{lxqt} package to the system
19167 @deftp {Data Type} lxqt-desktop-configuration
19168 Configuration record for the LXQt desktop environment.
19171 @item @code{lxqt} (default: @code{lxqt})
19172 The LXQT package to use.
19176 @deffn {Scheme Variable} enlightenment-desktop-service-type
19177 Return a service that adds the @code{enlightenment} package to the system
19178 profile, and extends dbus with actions from @code{efl}.
19181 @deftp {Data Type} enlightenment-desktop-service-configuration
19183 @item @code{enlightenment} (default: @code{enlightenment})
19184 The enlightenment package to use.
19188 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
19189 the default @code{%desktop-services} variable doesn't include any of
19190 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
19191 @code{%desktop-services} in the @code{services} field of your
19192 @code{operating-system}:
19195 (use-modules (gnu))
19196 (use-service-modules desktop)
19199 ;; cons* adds items to the list given as its last argument.
19200 (services (cons* (service gnome-desktop-service-type)
19201 (service xfce-desktop-service)
19202 %desktop-services))
19206 These desktop environments will then be available as options in the
19207 graphical login window.
19209 The actual service definitions included in @code{%desktop-services} and
19210 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
19211 are described below.
19213 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
19214 Return a service that runs the ``system bus'', using @var{dbus}, with
19215 support for @var{services}.
19217 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
19218 facility. Its system bus is used to allow system services to communicate
19219 and to be notified of system-wide events.
19221 @var{services} must be a list of packages that provide an
19222 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
19223 and policy files. For example, to allow avahi-daemon to use the system bus,
19224 @var{services} must be equal to @code{(list avahi)}.
19227 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
19228 Return a service that runs the @code{elogind} login and
19229 seat management daemon. @uref{https://github.com/elogind/elogind,
19230 Elogind} exposes a D-Bus interface that can be used to know which users
19231 are logged in, know what kind of sessions they have open, suspend the
19232 system, inhibit system suspend, reboot the system, and other tasks.
19234 Elogind handles most system-level power events for a computer, for
19235 example suspending the system when a lid is closed, or shutting it down
19236 when the power button is pressed.
19238 The @var{config} keyword argument specifies the configuration for
19239 elogind, and should be the result of an @code{(elogind-configuration
19240 (@var{parameter} @var{value})...)} invocation. Available parameters and
19241 their default values are:
19244 @item kill-user-processes?
19246 @item kill-only-users
19248 @item kill-exclude-users
19250 @item inhibit-delay-max-seconds
19252 @item handle-power-key
19254 @item handle-suspend-key
19256 @item handle-hibernate-key
19258 @item handle-lid-switch
19260 @item handle-lid-switch-docked
19262 @item handle-lid-switch-external-power
19264 @item power-key-ignore-inhibited?
19266 @item suspend-key-ignore-inhibited?
19268 @item hibernate-key-ignore-inhibited?
19270 @item lid-switch-ignore-inhibited?
19272 @item holdoff-timeout-seconds
19276 @item idle-action-seconds
19278 @item runtime-directory-size-percent
19280 @item runtime-directory-size
19284 @item suspend-state
19285 @code{("mem" "standby" "freeze")}
19288 @item hibernate-state
19290 @item hibernate-mode
19291 @code{("platform" "shutdown")}
19292 @item hybrid-sleep-state
19294 @item hybrid-sleep-mode
19295 @code{("suspend" "platform" "shutdown")}
19299 @deffn {Scheme Procedure} accountsservice-service @
19300 [#:accountsservice @var{accountsservice}]
19301 Return a service that runs AccountsService, a system service that can
19302 list available accounts, change their passwords, and so on.
19303 AccountsService integrates with PolicyKit to enable unprivileged users
19304 to acquire the capability to modify their system configuration.
19305 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
19306 accountsservice web site} for more information.
19308 The @var{accountsservice} keyword argument is the @code{accountsservice}
19309 package to expose as a service.
19312 @deffn {Scheme Procedure} polkit-service @
19313 [#:polkit @var{polkit}]
19314 Return a service that runs the
19315 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
19316 management service}, which allows system administrators to grant access to
19317 privileged operations in a structured way. By querying the Polkit service, a
19318 privileged system component can know when it should grant additional
19319 capabilities to ordinary users. For example, an ordinary user can be granted
19320 the capability to suspend the system if the user is logged in locally.
19323 @defvr {Scheme Variable} polkit-wheel-service
19324 Service that adds the @code{wheel} group as admins to the Polkit
19325 service. This makes it so that users in the @code{wheel} group are queried
19326 for their own passwords when performing administrative actions instead of
19327 @code{root}'s, similar to the behaviour used by @code{sudo}.
19330 @defvr {Scheme Variable} upower-service-type
19331 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
19332 system-wide monitor for power consumption and battery levels, with the given
19333 configuration settings.
19335 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
19336 notably used by GNOME.
19339 @deftp {Data Type} upower-configuration
19340 Data type representation the configuration for UPower.
19344 @item @code{upower} (default: @var{upower})
19345 Package to use for @code{upower}.
19347 @item @code{watts-up-pro?} (default: @code{#f})
19348 Enable the Watts Up Pro device.
19350 @item @code{poll-batteries?} (default: @code{#t})
19351 Enable polling the kernel for battery level changes.
19353 @item @code{ignore-lid?} (default: @code{#f})
19354 Ignore the lid state, this can be useful if it's incorrect on a device.
19356 @item @code{use-percentage-for-policy?} (default: @code{#f})
19357 Whether battery percentage based policy should be used. The default is to use
19358 the time left, change to @code{#t} to use the percentage.
19360 @item @code{percentage-low} (default: @code{10})
19361 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
19362 at which the battery is considered low.
19364 @item @code{percentage-critical} (default: @code{3})
19365 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
19366 at which the battery is considered critical.
19368 @item @code{percentage-action} (default: @code{2})
19369 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
19370 at which action will be taken.
19372 @item @code{time-low} (default: @code{1200})
19373 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
19374 seconds at which the battery is considered low.
19376 @item @code{time-critical} (default: @code{300})
19377 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
19378 seconds at which the battery is considered critical.
19380 @item @code{time-action} (default: @code{120})
19381 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
19382 seconds at which action will be taken.
19384 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
19385 The action taken when @code{percentage-action} or @code{time-action} is
19386 reached (depending on the configuration of @code{use-percentage-for-policy?}).
19388 Possible values are:
19398 @code{'hybrid-sleep}.
19404 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
19405 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
19406 UDisks}, a @dfn{disk management} daemon that provides user interfaces
19407 with notifications and ways to mount/unmount disks. Programs that talk
19408 to UDisks include the @command{udisksctl} command, part of UDisks, and
19409 GNOME Disks. Note that Udisks relies on the @command{mount} command, so
19410 it will only be able to use the file-system utilities installed in the
19411 system profile. For example if you want to be able to mount NTFS
19412 file-systems in read and write fashion, you'll need to have
19413 @code{ntfs-3g} installed system-wide.
19416 @deffn {Scheme Variable} colord-service-type
19417 This is the type of the service that runs @command{colord}, a system
19418 service with a D-Bus
19419 interface to manage the color profiles of input and output devices such as
19420 screens and scanners. It is notably used by the GNOME Color Manager graphical
19421 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
19422 site} for more information.
19425 @cindex scanner access
19426 @defvr {Scheme Variable} sane-service-type
19427 This service provides access to scanners @i{via}
19428 @uref{http://www.sane-project.org, SANE} by installing the necessary
19429 udev rules. It is included in @code{%desktop-services} (@pxref{Desktop
19430 Services}) and relies by default on @code{sane-backends-minimal} package
19431 (see below) for hardware support.
19434 @defvr {Scheme Variable} sane-backends-minimal
19435 The default package which the @code{sane-service-type} installs. It
19436 supports many recent scanners.
19439 @defvr {Scheme Variable} sane-backends
19440 This package includes support for all scanners that
19441 @code{sane-backends-minimal} supports, plus older Hewlett-Packard
19442 scanners supported by @code{hplip} package. In order to use this on
19443 a system which relies on @code{%desktop-services}, you may use
19444 @code{modify-services} (@pxref{Service Reference,
19445 @code{modify-services}}) as illustrated below:
19448 (use-modules (gnu))
19449 (use-service-modules
19452 (use-package-modules
19456 (define %my-desktop-services
19457 ;; List of desktop services that supports a broader range of scanners.
19458 (modify-services %desktop-services
19459 (sane-service-type _ => sane-backends)))
19463 (services %my-desktop-services)
19467 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
19468 Return a configuration allowing an application to access GeoClue
19469 location data. @var{name} is the Desktop ID of the application, without
19470 the @code{.desktop} part. If @var{allowed?} is true, the application
19471 will have access to location information by default. The boolean
19472 @var{system?} value indicates whether an application is a system component
19473 or not. Finally @var{users} is a list of UIDs of all users for which
19474 this application is allowed location info access. An empty users list
19475 means that all users are allowed.
19478 @defvr {Scheme Variable} %standard-geoclue-applications
19479 The standard list of well-known GeoClue application configurations,
19480 granting authority to the GNOME date-and-time utility to ask for the
19481 current location in order to set the time zone, and allowing the
19482 IceCat and Epiphany web browsers to request location information.
19483 IceCat and Epiphany both query the user before allowing a web page to
19484 know the user's location.
19487 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
19488 [#:whitelist '()] @
19489 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
19490 [#:submit-data? #f]
19491 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
19492 [#:submission-nick "geoclue"] @
19493 [#:applications %standard-geoclue-applications]
19494 Return a service that runs the GeoClue location service. This service
19495 provides a D-Bus interface to allow applications to request access to a
19496 user's physical location, and optionally to add information to online
19497 location databases. See
19498 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
19499 web site} for more information.
19502 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
19503 [@w{#:auto-enable? #f}]
19504 Return a service that runs the @command{bluetoothd} daemon, which
19505 manages all the Bluetooth devices and provides a number of D-Bus
19506 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
19507 powered automatically at boot, which can be useful when using a
19508 bluetooth keyboard or mouse.
19510 Users need to be in the @code{lp} group to access the D-Bus service.
19513 @defvr {Scheme Variable} gnome-keyring-service-type
19514 This is the type of the service that adds the
19515 @uref{https://wiki.gnome.org/Projects/GnomeKeyring, GNOME Keyring}. Its
19516 value is a @code{gnome-keyring-configuration} object (see below).
19518 This service adds the @code{gnome-keyring} package to the system profile
19519 and extends PAM with entries using @code{pam_gnome_keyring.so}, unlocking
19520 a user's login keyring when they log in or setting its password with passwd.
19523 @deftp {Data Type} gnome-keyring-configuration
19524 Configuration record for the GNOME Keyring service.
19527 @item @code{keyring} (default: @code{gnome-keyring})
19528 The GNOME keyring package to use.
19530 @item @code{pam-services}
19531 A list of @code{(@var{service} . @var{kind})} pairs denoting PAM
19532 services to extend, where @var{service} is the name of an existing
19533 service to extend and @var{kind} is one of @code{login} or
19536 If @code{login} is given, it adds an optional
19537 @code{pam_gnome_keyring.so} to the auth block without arguments and to
19538 the session block with @code{auto_start}. If @code{passwd} is given, it
19539 adds an optional @code{pam_gnome_keyring.so} to the password block
19542 By default, this field contains ``gdm-password'' with the value @code{login}
19543 and ``passwd'' is with the value @code{passwd}.
19548 @node Sound Services
19549 @subsection Sound Services
19551 @cindex sound support
19553 @cindex PulseAudio, sound support
19555 The @code{(gnu services sound)} module provides a service to configure the
19556 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
19557 preferred ALSA output driver.
19559 @deffn {Scheme Variable} alsa-service-type
19560 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
19561 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
19562 configuration file. The value for this type is a @command{alsa-configuration}
19563 record as in this example:
19566 (service alsa-service-type)
19569 See below for details about @code{alsa-configuration}.
19572 @deftp {Data Type} alsa-configuration
19573 Data type representing the configuration for @code{alsa-service}.
19576 @item @code{alsa-plugins} (default: @var{alsa-plugins})
19577 @code{alsa-plugins} package to use.
19579 @item @code{pulseaudio?} (default: @var{#t})
19580 Whether ALSA applications should transparently be made to use the
19581 @uref{https://www.pulseaudio.org/, PulseAudio} sound server.
19583 Using PulseAudio allows you to run several sound-producing applications
19584 at the same time and to individual control them @i{via}
19585 @command{pavucontrol}, among other things.
19587 @item @code{extra-options} (default: @var{""})
19588 String to append to the @file{/etc/asound.conf} file.
19593 Individual users who want to override the system configuration of ALSA can do
19594 it with the @file{~/.asoundrc} file:
19597 # In guix, we have to specify the absolute path for plugins.
19599 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
19602 # Routing ALSA to jack:
19603 # <http://jackaudio.org/faq/routing_alsa.html>.
19607 0 system:playback_1
19608 1 system:playback_2
19625 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
19628 @deffn {Scheme Variable} pulseaudio-service-type
19629 This is the type for the @uref{https://www.pulseaudio.org/, PulseAudio}
19630 sound server. It exists to allow system overrides of the default settings
19631 via @code{pulseaudio-configuration}, see below.
19634 This service overrides per-user configuration files. If you want
19635 PulseAudio to honor configuration files in @file{~/.config/pulse} you
19636 have to unset the environment variables @env{PULSE_CONFIG} and
19637 @env{PULSE_CLIENTCONFIG} in your @file{~/.bash_profile}.
19641 This service on its own does not ensure, that the @code{pulseaudio} package
19642 exists on your machine. It merely adds configuration files for it, as
19643 detailed below. In the (admittedly unlikely) case, that you find yourself
19644 without a @code{pulseaudio} package, consider enabling it through the
19645 @code{alsa-service-type} above.
19649 @deftp {Data Type} pulseaudio-configuration
19650 Data type representing the configuration for @code{pulseaudio-service}.
19653 @item @code{client-conf} (default: @code{'()})
19654 List of settings to set in @file{client.conf}.
19655 Accepts a list of strings or a symbol-value pairs. A string will be
19656 inserted as-is with a newline added. A pair will be formatted as
19657 ``key = value'', again with a newline added.
19659 @item @code{daemon-conf} (default: @code{'((flat-volumes . no))})
19660 List of settings to set in @file{daemon.conf}, formatted just like
19663 @item @code{script-file} (default: @code{(file-append pulseaudio "/etc/pulse/default.pa")})
19664 Script file to use as @file{default.pa}.
19666 @item @code{system-script-file} (default: @code{(file-append pulseaudio "/etc/pulse/system.pa")})
19667 Script file to use as @file{system.pa}.
19671 @deffn {Scheme Variable} ladspa-service-type
19672 This service sets the @var{LADSPA_PATH} variable, so that programs, which
19673 respect it, e.g. PulseAudio, can load LADSPA plugins.
19675 The following example will setup the service to enable modules from the
19676 @code{swh-plugins} package:
19679 (service ladspa-service-type
19680 (ladspa-configuration (plugins (list swh-plugins))))
19683 See @uref{http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html} for the
19688 @node Database Services
19689 @subsection Database Services
19693 The @code{(gnu services databases)} module provides the following services.
19695 @subsubheading PostgreSQL
19697 The following example describes a PostgreSQL service with the default
19701 (service postgresql-service-type
19702 (postgresql-configuration
19703 (postgresql postgresql-10)))
19706 If the services fails to start, it may be due to an incompatible
19707 cluster already present in @var{data-directory}. Adjust it (or, if you
19708 don't need the cluster anymore, delete @var{data-directory}), then
19709 restart the service.
19711 Peer authentication is used by default and the @code{postgres} user
19712 account has no shell, which prevents the direct execution of @code{psql}
19713 commands as this user. To use @code{psql}, you can temporarily log in
19714 as @code{postgres} using a shell, create a PostgreSQL superuser with the
19715 same name as one of the system users and then create the associated
19719 sudo -u postgres -s /bin/sh
19720 createuser --interactive
19721 createdb $MY_USER_LOGIN # Replace appropriately.
19724 @deftp {Data Type} postgresql-configuration
19725 Data type representing the configuration for the
19726 @code{postgresql-service-type}.
19729 @item @code{postgresql}
19730 PostgreSQL package to use for the service.
19732 @item @code{port} (default: @code{5432})
19733 Port on which PostgreSQL should listen.
19735 @item @code{locale} (default: @code{"en_US.utf8"})
19736 Locale to use as the default when creating the database cluster.
19738 @item @code{config-file} (default: @code{(postgresql-config-file)})
19739 The configuration file to use when running PostgreSQL@. The default
19740 behaviour uses the postgresql-config-file record with the default values
19743 @item @code{log-directory} (default: @code{"/var/log/postgresql"})
19744 The directory where @command{pg_ctl} output will be written in a file
19745 named @code{"pg_ctl.log"}. This file can be useful to debug PostgreSQL
19746 configuration errors for instance.
19748 @item @code{data-directory} (default: @code{"/var/lib/postgresql/data"})
19749 Directory in which to store the data.
19751 @item @code{extension-packages} (default: @code{'()})
19752 @cindex postgresql extension-packages
19753 Additional extensions are loaded from packages listed in
19754 @var{extension-packages}. Extensions are available at runtime. For instance,
19755 to create a geographic database using the @code{postgis} extension, a user can
19756 configure the postgresql-service as in this example:
19760 (use-package-modules databases geo)
19764 ;; postgresql is required to run `psql' but postgis is not required for
19765 ;; proper operation.
19766 (packages (cons* postgresql %base-packages))
19769 (service postgresql-service-type
19770 (postgresql-configuration
19771 (postgresql postgresql-10)
19772 (extension-packages (list postgis))))
19776 Then the extension becomes visible and you can initialise an empty geographic
19777 database in this way:
19781 > create database postgistest;
19782 > \connect postgistest;
19783 > create extension postgis;
19784 > create extension postgis_topology;
19787 There is no need to add this field for contrib extensions such as hstore or
19788 dblink as they are already loadable by postgresql. This field is only
19789 required to add extensions provided by other packages.
19794 @deftp {Data Type} postgresql-config-file
19795 Data type representing the PostgreSQL configuration file. As shown in
19796 the following example, this can be used to customize the configuration
19797 of PostgreSQL@. Note that you can use any G-expression or filename in
19798 place of this record, if you already have a configuration file you'd
19799 like to use for example.
19802 (service postgresql-service-type
19803 (postgresql-configuration
19805 (postgresql-config-file
19806 (log-destination "stderr")
19808 (plain-file "pg_hba.conf"
19810 local all all trust
19811 host all all 127.0.0.1/32 md5
19812 host all all ::1/128 md5"))
19814 '(("session_preload_libraries" "auto_explain")
19815 ("random_page_cost" 2)
19816 ("auto_explain.log_min_duration" "100 ms")
19817 ("work_mem" "500 MB")
19818 ("logging_collector" #t)
19819 ("log_directory" "/var/log/postgresql")))))))
19823 @item @code{log-destination} (default: @code{"syslog"})
19824 The logging method to use for PostgreSQL@. Multiple values are accepted,
19825 separated by commas.
19827 @item @code{hba-file} (default: @code{%default-postgres-hba})
19828 Filename or G-expression for the host-based authentication
19831 @item @code{ident-file} (default: @code{%default-postgres-ident})
19832 Filename or G-expression for the user name mapping configuration.
19834 @item @code{socket-directory} (default: @code{#false})
19835 Specifies the directory of the Unix-domain socket(s) on which PostgreSQL
19836 is to listen for connections from client applications. If set to
19837 @code{""} PostgreSQL does not listen on any Unix-domain sockets, in
19838 which case only TCP/IP sockets can be used to connect to the server.
19840 By default, the @code{#false} value means the PostgreSQL default value
19841 will be used, which is currently @samp{/tmp}.
19843 @item @code{extra-config} (default: @code{'()})
19844 List of additional keys and values to include in the PostgreSQL config
19845 file. Each entry in the list should be a list where the first element
19846 is the key, and the remaining elements are the values.
19848 The values can be numbers, booleans or strings and will be mapped to
19849 PostgreSQL parameters types @code{Boolean}, @code{String},
19850 @code{Numeric}, @code{Numeric with Unit} and @code{Enumerated} described
19851 @uref{https://www.postgresql.org/docs/current/config-setting.html,
19857 @deffn {Scheme Variable} postgresql-role-service-type
19858 This service allows to create PostgreSQL roles and databases after
19859 PostgreSQL service start. Here is an example of its use.
19862 (service postgresql-role-service-type
19863 (postgresql-role-configuration
19865 (list (postgresql-role
19867 (create-database? #t))))))
19870 This service can be extended with extra roles, as in this
19874 (service-extension postgresql-role-service-type
19875 (const (postgresql-role
19877 (create-database? #t))))
19881 @deftp {Data Type} postgresql-role
19882 PostgreSQL manages database access permissions using the concept of
19883 roles. A role can be thought of as either a database user, or a group
19884 of database users, depending on how the role is set up. Roles can own
19885 database objects (for example, tables) and can assign privileges on
19886 those objects to other roles to control who has access to which objects.
19892 @item @code{permissions} (default: @code{'(createdb login)})
19893 The role permissions list. Supported permissions are @code{bypassrls},
19894 @code{createdb}, @code{createrole}, @code{login}, @code{replication} and
19897 @item @code{create-database?} (default: @code{#f})
19898 Whether to create a database with the same name as the role.
19903 @deftp {Data Type} postgresql-role-configuration
19904 Data type representing the configuration of
19905 @var{postgresql-role-service-type}.
19908 @item @code{host} (default: @code{"/var/run/postgresql"})
19909 The PostgreSQL host to connect to.
19911 @item @code{log} (default: @code{"/var/log/postgresql_roles.log"})
19912 File name of the log file.
19914 @item @code{roles} (default: @code{'()})
19915 The initial PostgreSQL roles to create.
19919 @subsubheading MariaDB/MySQL
19921 @defvr {Scheme Variable} mysql-service-type
19922 This is the service type for a MySQL or MariaDB database server. Its value
19923 is a @code{mysql-configuration} object that specifies which package to use,
19924 as well as various settings for the @command{mysqld} daemon.
19927 @deftp {Data Type} mysql-configuration
19928 Data type representing the configuration of @var{mysql-service-type}.
19931 @item @code{mysql} (default: @var{mariadb})
19932 Package object of the MySQL database server, can be either @var{mariadb}
19935 For MySQL, a temporary root password will be displayed at activation time.
19936 For MariaDB, the root password is empty.
19938 @item @code{bind-address} (default: @code{"127.0.0.1"})
19939 The IP on which to listen for network connections. Use @code{"0.0.0.0"}
19940 to bind to all available network interfaces.
19942 @item @code{port} (default: @code{3306})
19943 TCP port on which the database server listens for incoming connections.
19945 @item @code{socket} (default: @code{"/run/mysqld/mysqld.sock"})
19946 Socket file to use for local (non-network) connections.
19948 @item @code{extra-content} (default: @code{""})
19949 Additional settings for the @file{my.cnf} configuration file.
19951 @item @code{auto-upgrade?} (default: @code{#t})
19952 Whether to automatically run @command{mysql_upgrade} after starting the
19953 service. This is necessary to upgrade the @dfn{system schema} after
19954 ``major'' updates (such as switching from MariaDB 10.4 to 10.5), but can
19955 be disabled if you would rather do that manually.
19960 @subsubheading Memcached
19962 @defvr {Scheme Variable} memcached-service-type
19963 This is the service type for the @uref{https://memcached.org/,
19964 Memcached} service, which provides a distributed in memory cache. The
19965 value for the service type is a @code{memcached-configuration} object.
19969 (service memcached-service-type)
19972 @deftp {Data Type} memcached-configuration
19973 Data type representing the configuration of memcached.
19976 @item @code{memcached} (default: @code{memcached})
19977 The Memcached package to use.
19979 @item @code{interfaces} (default: @code{'("0.0.0.0")})
19980 Network interfaces on which to listen.
19982 @item @code{tcp-port} (default: @code{11211})
19983 Port on which to accept connections.
19985 @item @code{udp-port} (default: @code{11211})
19986 Port on which to accept UDP connections on, a value of 0 will disable
19987 listening on a UDP socket.
19989 @item @code{additional-options} (default: @code{'()})
19990 Additional command line options to pass to @code{memcached}.
19994 @subsubheading Redis
19996 @defvr {Scheme Variable} redis-service-type
19997 This is the service type for the @uref{https://redis.io/, Redis}
19998 key/value store, whose value is a @code{redis-configuration} object.
20001 @deftp {Data Type} redis-configuration
20002 Data type representing the configuration of redis.
20005 @item @code{redis} (default: @code{redis})
20006 The Redis package to use.
20008 @item @code{bind} (default: @code{"127.0.0.1"})
20009 Network interface on which to listen.
20011 @item @code{port} (default: @code{6379})
20012 Port on which to accept connections on, a value of 0 will disable
20013 listening on a TCP socket.
20015 @item @code{working-directory} (default: @code{"/var/lib/redis"})
20016 Directory in which to store the database and related files.
20020 @node Mail Services
20021 @subsection Mail Services
20025 The @code{(gnu services mail)} module provides Guix service definitions
20026 for email services: IMAP, POP3, and LMTP servers, as well as mail
20027 transport agents (MTAs). Lots of acronyms! These services are detailed
20028 in the subsections below.
20030 @subsubheading Dovecot Service
20032 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
20033 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
20036 By default, Dovecot does not need much configuration; the default
20037 configuration object created by @code{(dovecot-configuration)} will
20038 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
20039 certificate will be generated for TLS-protected connections, though
20040 Dovecot will also listen on cleartext ports by default. There are a
20041 number of options, though, which mail administrators might need to change,
20042 and as is the case with other services, Guix allows the system
20043 administrator to specify these parameters via a uniform Scheme interface.
20045 For example, to specify that mail is located at @code{maildir~/.mail},
20046 one would instantiate the Dovecot service like this:
20049 (dovecot-service #:config
20050 (dovecot-configuration
20051 (mail-location "maildir:~/.mail")))
20054 The available configuration parameters follow. Each parameter
20055 definition is preceded by its type; for example, @samp{string-list foo}
20056 indicates that the @code{foo} parameter should be specified as a list of
20057 strings. There is also a way to specify the configuration as a string,
20058 if you have an old @code{dovecot.conf} file that you want to port over
20059 from some other system; see the end for more details.
20061 @c The following documentation was initially generated by
20062 @c (generate-documentation) in (gnu services mail). Manually maintained
20063 @c documentation is better, so we shouldn't hesitate to edit below as
20064 @c needed. However if the change you want to make to this documentation
20065 @c can be done in an automated way, it's probably easier to change
20066 @c (generate-documentation) than to make it below and have to deal with
20067 @c the churn as dovecot updates.
20069 Available @code{dovecot-configuration} fields are:
20071 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
20072 The dovecot package.
20075 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
20076 A list of IPs or hosts where to listen for connections. @samp{*}
20077 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
20078 interfaces. If you want to specify non-default ports or anything more
20079 complex, customize the address and port fields of the
20080 @samp{inet-listener} of the specific services you are interested in.
20083 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
20084 List of protocols we want to serve. Available protocols include
20085 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
20087 Available @code{protocol-configuration} fields are:
20089 @deftypevr {@code{protocol-configuration} parameter} string name
20090 The name of the protocol.
20093 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
20094 UNIX socket path to the master authentication server to find users.
20095 This is used by imap (for shared users) and lda.
20096 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
20099 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
20100 Space separated list of plugins to load.
20103 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
20104 Maximum number of IMAP connections allowed for a user from each IP
20105 address. NOTE: The username is compared case-sensitively.
20106 Defaults to @samp{10}.
20111 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
20112 List of services to enable. Available services include @samp{imap},
20113 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
20116 Available @code{service-configuration} fields are:
20118 @deftypevr {@code{service-configuration} parameter} string kind
20119 The service kind. Valid values include @code{director},
20120 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
20121 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
20122 @code{tcpwrap}, @code{quota-warning}, or anything else.
20125 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
20126 Listeners for the service. A listener is either a
20127 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
20128 an @code{inet-listener-configuration}.
20129 Defaults to @samp{()}.
20131 Available @code{unix-listener-configuration} fields are:
20133 @deftypevr {@code{unix-listener-configuration} parameter} string path
20134 Path to the file, relative to @code{base-dir} field. This is also used as
20138 @deftypevr {@code{unix-listener-configuration} parameter} string mode
20139 The access mode for the socket.
20140 Defaults to @samp{"0600"}.
20143 @deftypevr {@code{unix-listener-configuration} parameter} string user
20144 The user to own the socket.
20145 Defaults to @samp{""}.
20148 @deftypevr {@code{unix-listener-configuration} parameter} string group
20149 The group to own the socket.
20150 Defaults to @samp{""}.
20154 Available @code{fifo-listener-configuration} fields are:
20156 @deftypevr {@code{fifo-listener-configuration} parameter} string path
20157 Path to the file, relative to @code{base-dir} field. This is also used as
20161 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
20162 The access mode for the socket.
20163 Defaults to @samp{"0600"}.
20166 @deftypevr {@code{fifo-listener-configuration} parameter} string user
20167 The user to own the socket.
20168 Defaults to @samp{""}.
20171 @deftypevr {@code{fifo-listener-configuration} parameter} string group
20172 The group to own the socket.
20173 Defaults to @samp{""}.
20177 Available @code{inet-listener-configuration} fields are:
20179 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
20180 The protocol to listen for.
20183 @deftypevr {@code{inet-listener-configuration} parameter} string address
20184 The address on which to listen, or empty for all addresses.
20185 Defaults to @samp{""}.
20188 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
20189 The port on which to listen.
20192 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
20193 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
20195 Defaults to @samp{#t}.
20200 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
20201 Maximum number of simultaneous client connections per process. Once
20202 this number of connections is received, the next incoming connection
20203 will prompt Dovecot to spawn another process. If set to 0,
20204 @code{default-client-limit} is used instead.
20206 Defaults to @samp{0}.
20210 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
20211 Number of connections to handle before starting a new process.
20212 Typically the only useful values are 0 (unlimited) or 1. 1 is more
20213 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
20214 Defaults to @samp{1}.
20218 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
20219 Maximum number of processes that can exist for this service. If set to
20220 0, @code{default-process-limit} is used instead.
20222 Defaults to @samp{0}.
20226 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
20227 Number of processes to always keep waiting for more connections.
20228 Defaults to @samp{0}.
20231 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
20232 If you set @samp{service-count 0}, you probably need to grow
20234 Defaults to @samp{256000000}.
20239 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
20240 Dict configuration, as created by the @code{dict-configuration}
20243 Available @code{dict-configuration} fields are:
20245 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
20246 A list of key-value pairs that this dict should hold.
20247 Defaults to @samp{()}.
20252 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
20253 A list of passdb configurations, each one created by the
20254 @code{passdb-configuration} constructor.
20256 Available @code{passdb-configuration} fields are:
20258 @deftypevr {@code{passdb-configuration} parameter} string driver
20259 The driver that the passdb should use. Valid values include
20260 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
20262 Defaults to @samp{"pam"}.
20265 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
20266 Space separated list of arguments to the passdb driver.
20267 Defaults to @samp{""}.
20272 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
20273 List of userdb configurations, each one created by the
20274 @code{userdb-configuration} constructor.
20276 Available @code{userdb-configuration} fields are:
20278 @deftypevr {@code{userdb-configuration} parameter} string driver
20279 The driver that the userdb should use. Valid values include
20280 @samp{passwd} and @samp{static}.
20281 Defaults to @samp{"passwd"}.
20284 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
20285 Space separated list of arguments to the userdb driver.
20286 Defaults to @samp{""}.
20289 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
20290 Override fields from passwd.
20291 Defaults to @samp{()}.
20296 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
20297 Plug-in configuration, created by the @code{plugin-configuration}
20301 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
20302 List of namespaces. Each item in the list is created by the
20303 @code{namespace-configuration} constructor.
20305 Available @code{namespace-configuration} fields are:
20307 @deftypevr {@code{namespace-configuration} parameter} string name
20308 Name for this namespace.
20311 @deftypevr {@code{namespace-configuration} parameter} string type
20312 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
20313 Defaults to @samp{"private"}.
20316 @deftypevr {@code{namespace-configuration} parameter} string separator
20317 Hierarchy separator to use. You should use the same separator for
20318 all namespaces or some clients get confused. @samp{/} is usually a good
20319 one. The default however depends on the underlying mail storage
20321 Defaults to @samp{""}.
20324 @deftypevr {@code{namespace-configuration} parameter} string prefix
20325 Prefix required to access this namespace. This needs to be
20326 different for all namespaces. For example @samp{Public/}.
20327 Defaults to @samp{""}.
20330 @deftypevr {@code{namespace-configuration} parameter} string location
20331 Physical location of the mailbox. This is in the same format as
20332 mail_location, which is also the default for it.
20333 Defaults to @samp{""}.
20336 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
20337 There can be only one INBOX, and this setting defines which
20339 Defaults to @samp{#f}.
20342 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
20343 If namespace is hidden, it's not advertised to clients via NAMESPACE
20344 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
20345 useful when converting from another server with different namespaces
20346 which you want to deprecate but still keep working. For example you can
20347 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
20349 Defaults to @samp{#f}.
20352 @deftypevr {@code{namespace-configuration} parameter} boolean list?
20353 Show the mailboxes under this namespace with the LIST command. This
20354 makes the namespace visible for clients that do not support the NAMESPACE
20355 extension. The special @code{children} value lists child mailboxes, but
20356 hides the namespace prefix.
20357 Defaults to @samp{#t}.
20360 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
20361 Namespace handles its own subscriptions. If set to @code{#f}, the
20362 parent namespace handles them. The empty prefix should always have this
20364 Defaults to @samp{#t}.
20367 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
20368 List of predefined mailboxes in this namespace.
20369 Defaults to @samp{()}.
20371 Available @code{mailbox-configuration} fields are:
20373 @deftypevr {@code{mailbox-configuration} parameter} string name
20374 Name for this mailbox.
20377 @deftypevr {@code{mailbox-configuration} parameter} string auto
20378 @samp{create} will automatically create this mailbox.
20379 @samp{subscribe} will both create and subscribe to the mailbox.
20380 Defaults to @samp{"no"}.
20383 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
20384 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
20385 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
20386 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
20387 Defaults to @samp{()}.
20394 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
20395 Base directory where to store runtime data.
20396 Defaults to @samp{"/var/run/dovecot/"}.
20399 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
20400 Greeting message for clients.
20401 Defaults to @samp{"Dovecot ready."}.
20404 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
20405 List of trusted network ranges. Connections from these IPs are
20406 allowed to override their IP addresses and ports (for logging and for
20407 authentication checks). @samp{disable-plaintext-auth} is also ignored
20408 for these networks. Typically you would specify your IMAP proxy servers
20410 Defaults to @samp{()}.
20413 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
20414 List of login access check sockets (e.g.@: tcpwrap).
20415 Defaults to @samp{()}.
20418 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
20419 Show more verbose process titles (in ps). Currently shows user name
20420 and IP address. Useful for seeing who is actually using the IMAP
20421 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
20423 Defaults to @samp{#f}.
20426 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
20427 Should all processes be killed when Dovecot master process shuts down.
20428 Setting this to @code{#f} means that Dovecot can be upgraded without
20429 forcing existing client connections to close (although that could also
20430 be a problem if the upgrade is e.g.@: due to a security fix).
20431 Defaults to @samp{#t}.
20434 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
20435 If non-zero, run mail commands via this many connections to doveadm
20436 server, instead of running them directly in the same process.
20437 Defaults to @samp{0}.
20440 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
20441 UNIX socket or host:port used for connecting to doveadm server.
20442 Defaults to @samp{"doveadm-server"}.
20445 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
20446 List of environment variables that are preserved on Dovecot startup
20447 and passed down to all of its child processes. You can also give
20448 key=value pairs to always set specific settings.
20451 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
20452 Disable LOGIN command and all other plaintext authentications unless
20453 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
20454 matches the local IP (i.e.@: you're connecting from the same computer),
20455 the connection is considered secure and plaintext authentication is
20456 allowed. See also ssl=required setting.
20457 Defaults to @samp{#t}.
20460 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
20461 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
20462 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
20463 for caching to be used.
20464 Defaults to @samp{0}.
20467 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
20468 Time to live for cached data. After TTL expires the cached record
20469 is no longer used, *except* if the main database lookup returns internal
20470 failure. We also try to handle password changes automatically: If
20471 user's previous authentication was successful, but this one wasn't, the
20472 cache isn't used. For now this works only with plaintext
20474 Defaults to @samp{"1 hour"}.
20477 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
20478 TTL for negative hits (user not found, password mismatch).
20479 0 disables caching them completely.
20480 Defaults to @samp{"1 hour"}.
20483 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
20484 List of realms for SASL authentication mechanisms that need them.
20485 You can leave it empty if you don't want to support multiple realms.
20486 Many clients simply use the first one listed here, so keep the default
20488 Defaults to @samp{()}.
20491 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
20492 Default realm/domain to use if none was specified. This is used for
20493 both SASL realms and appending @@domain to username in plaintext
20495 Defaults to @samp{""}.
20498 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
20499 List of allowed characters in username. If the user-given username
20500 contains a character not listed in here, the login automatically fails.
20501 This is just an extra check to make sure user can't exploit any
20502 potential quote escaping vulnerabilities with SQL/LDAP databases. If
20503 you want to allow all characters, set this value to empty.
20504 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
20507 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
20508 Username character translations before it's looked up from
20509 databases. The value contains series of from -> to characters. For
20510 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
20511 translated to @samp{@@}.
20512 Defaults to @samp{""}.
20515 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
20516 Username formatting before it's looked up from databases. You can
20517 use the standard variables here, e.g.@: %Lu would lowercase the username,
20518 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
20519 change the @samp{@@} into @samp{-AT-}. This translation is done after
20520 @samp{auth-username-translation} changes.
20521 Defaults to @samp{"%Lu"}.
20524 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
20525 If you want to allow master users to log in by specifying the master
20526 username within the normal username string (i.e.@: not using SASL
20527 mechanism's support for it), you can specify the separator character
20528 here. The format is then <username><separator><master username>.
20529 UW-IMAP uses @samp{*} as the separator, so that could be a good
20531 Defaults to @samp{""}.
20534 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
20535 Username to use for users logging in with ANONYMOUS SASL
20537 Defaults to @samp{"anonymous"}.
20540 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
20541 Maximum number of dovecot-auth worker processes. They're used to
20542 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
20543 They're automatically created and destroyed as needed.
20544 Defaults to @samp{30}.
20547 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
20548 Host name to use in GSSAPI principal names. The default is to use
20549 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
20550 allow all keytab entries.
20551 Defaults to @samp{""}.
20554 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
20555 Kerberos keytab to use for the GSSAPI mechanism. Will use the
20556 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
20557 need to change the auth service to run as root to be able to read this
20559 Defaults to @samp{""}.
20562 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
20563 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
20564 and @samp{ntlm-auth} helper.
20565 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
20566 Defaults to @samp{#f}.
20569 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
20570 Path for Samba's @samp{ntlm-auth} helper binary.
20571 Defaults to @samp{"/usr/bin/ntlm_auth"}.
20574 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
20575 Time to delay before replying to failed authentications.
20576 Defaults to @samp{"2 secs"}.
20579 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
20580 Require a valid SSL client certificate or the authentication
20582 Defaults to @samp{#f}.
20585 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
20586 Take the username from client's SSL certificate, using
20587 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
20589 Defaults to @samp{#f}.
20592 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
20593 List of wanted authentication mechanisms. Supported mechanisms are:
20594 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
20595 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
20596 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
20597 @samp{disable-plaintext-auth} setting.
20600 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
20601 List of IPs or hostnames to all director servers, including ourself.
20602 Ports can be specified as ip:port. The default port is the same as what
20603 director service's @samp{inet-listener} is using.
20604 Defaults to @samp{()}.
20607 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
20608 List of IPs or hostnames to all backend mail servers. Ranges are
20609 allowed too, like 10.0.0.10-10.0.0.30.
20610 Defaults to @samp{()}.
20613 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
20614 How long to redirect users to a specific server after it no longer
20615 has any connections.
20616 Defaults to @samp{"15 min"}.
20619 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
20620 How the username is translated before being hashed. Useful values
20621 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
20622 are shared within domain.
20623 Defaults to @samp{"%Lu"}.
20626 @deftypevr {@code{dovecot-configuration} parameter} string log-path
20627 Log file to use for error messages. @samp{syslog} logs to syslog,
20628 @samp{/dev/stderr} logs to stderr.
20629 Defaults to @samp{"syslog"}.
20632 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
20633 Log file to use for informational messages. Defaults to
20635 Defaults to @samp{""}.
20638 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
20639 Log file to use for debug messages. Defaults to
20640 @samp{info-log-path}.
20641 Defaults to @samp{""}.
20644 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
20645 Syslog facility to use if you're logging to syslog. Usually if you
20646 don't want to use @samp{mail}, you'll use local0..local7. Also other
20647 standard facilities are supported.
20648 Defaults to @samp{"mail"}.
20651 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
20652 Log unsuccessful authentication attempts and the reasons why they
20654 Defaults to @samp{#f}.
20657 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
20658 In case of password mismatches, log the attempted password. Valid
20659 values are no, plain and sha1. sha1 can be useful for detecting brute
20660 force password attempts vs. user simply trying the same password over
20661 and over again. You can also truncate the value to n chars by appending
20662 ":n" (e.g.@: sha1:6).
20663 Defaults to @samp{"no"}.
20666 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
20667 Even more verbose logging for debugging purposes. Shows for example
20669 Defaults to @samp{#f}.
20672 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
20673 In case of password mismatches, log the passwords and used scheme so
20674 the problem can be debugged. Enabling this also enables
20676 Defaults to @samp{#f}.
20679 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
20680 Enable mail process debugging. This can help you figure out why
20681 Dovecot isn't finding your mails.
20682 Defaults to @samp{#f}.
20685 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
20686 Show protocol level SSL errors.
20687 Defaults to @samp{#f}.
20690 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
20691 Prefix for each line written to log file. % codes are in
20692 strftime(3) format.
20693 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
20696 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
20697 List of elements we want to log. The elements which have a
20698 non-empty variable value are joined together to form a comma-separated
20702 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
20703 Login log format. %s contains @samp{login-log-format-elements}
20704 string, %$ contains the data we want to log.
20705 Defaults to @samp{"%$: %s"}.
20708 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
20709 Log prefix for mail processes. See doc/wiki/Variables.txt for list
20710 of possible variables you can use.
20711 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
20714 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
20715 Format to use for logging mail deliveries. You can use variables:
20718 Delivery status message (e.g.@: @samp{saved to INBOX})
20730 Defaults to @samp{"msgid=%m: %$"}.
20733 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
20734 Location for users' mailboxes. The default is empty, which means
20735 that Dovecot tries to find the mailboxes automatically. This won't work
20736 if the user doesn't yet have any mail, so you should explicitly tell
20737 Dovecot the full location.
20739 If you're using mbox, giving a path to the INBOX
20740 file (e.g.@: @file{/var/mail/%u}) isn't enough. You'll also need to tell Dovecot
20741 where the other mailboxes are kept. This is called the @emph{root mail
20742 directory}, and it must be the first path given in the
20743 @samp{mail-location} setting.
20745 There are a few special variables you can use, e.g.:
20751 user part in user@@domain, same as %u if there's no domain
20753 domain part in user@@domain, empty if there's no domain
20758 See doc/wiki/Variables.txt for full list. Some examples:
20760 @item maildir:~/Maildir
20761 @item mbox:~/mail:INBOX=/var/mail/%u
20762 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
20764 Defaults to @samp{""}.
20767 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
20768 System user and group used to access mails. If you use multiple,
20769 userdb can override these by returning uid or gid fields. You can use
20770 either numbers or names. <doc/wiki/UserIds.txt>.
20771 Defaults to @samp{""}.
20774 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
20776 Defaults to @samp{""}.
20779 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
20780 Group to enable temporarily for privileged operations. Currently
20781 this is used only with INBOX when either its initial creation or
20782 dotlocking fails. Typically this is set to @samp{"mail"} to give access to
20784 Defaults to @samp{""}.
20787 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
20788 Grant access to these supplementary groups for mail processes.
20789 Typically these are used to set up access to shared mailboxes. Note
20790 that it may be dangerous to set these if users can create symlinks
20791 (e.g.@: if @samp{mail} group is set here, @code{ln -s /var/mail ~/mail/var}
20792 could allow a user to delete others' mailboxes, or @code{ln -s
20793 /secret/shared/box ~/mail/mybox} would allow reading it). Defaults to
20797 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
20798 Allow full file system access to clients. There's no access checks
20799 other than what the operating system does for the active UID/GID@. It
20800 works with both maildir and mboxes, allowing you to prefix mailboxes
20801 names with e.g.@: @file{/path/} or @file{~user/}.
20802 Defaults to @samp{#f}.
20805 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
20806 Don't use @code{mmap()} at all. This is required if you store indexes to
20807 shared file systems (NFS or clustered file system).
20808 Defaults to @samp{#f}.
20811 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
20812 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
20813 supports @samp{O_EXCL} since version 3, so this should be safe to use
20814 nowadays by default.
20815 Defaults to @samp{#t}.
20818 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
20819 When to use fsync() or fdatasync() calls:
20822 Whenever necessary to avoid losing important data
20824 Useful with e.g.@: NFS when @code{write()}s are delayed
20826 Never use it (best performance, but crashes can lose data).
20828 Defaults to @samp{"optimized"}.
20831 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
20832 Mail storage exists in NFS@. Set this to yes to make Dovecot flush
20833 NFS caches whenever needed. If you're using only a single mail server
20835 Defaults to @samp{#f}.
20838 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
20839 Mail index files also exist in NFS@. Setting this to yes requires
20840 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
20841 Defaults to @samp{#f}.
20844 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
20845 Locking method for index files. Alternatives are fcntl, flock and
20846 dotlock. Dotlocking uses some tricks which may create more disk I/O
20847 than other locking methods. NFS users: flock doesn't work, remember to
20848 change @samp{mmap-disable}.
20849 Defaults to @samp{"fcntl"}.
20852 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
20853 Directory in which LDA/LMTP temporarily stores incoming mails >128
20855 Defaults to @samp{"/tmp"}.
20858 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
20859 Valid UID range for users. This is mostly to make sure that users can't
20860 log in as daemons or other system users. Note that denying root logins is
20861 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
20863 Defaults to @samp{500}.
20866 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
20868 Defaults to @samp{0}.
20871 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
20872 Valid GID range for users. Users having non-valid GID as primary group ID
20873 aren't allowed to log in. If user belongs to supplementary groups with
20874 non-valid GIDs, those groups are not set.
20875 Defaults to @samp{1}.
20878 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
20880 Defaults to @samp{0}.
20883 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
20884 Maximum allowed length for mail keyword name. It's only forced when
20885 trying to create new keywords.
20886 Defaults to @samp{50}.
20889 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
20890 List of directories under which chrooting is allowed for mail
20891 processes (i.e.@: @file{/var/mail} will allow chrooting to @file{/var/mail/foo/bar}
20892 too). This setting doesn't affect @samp{login-chroot}
20893 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
20894 @samp{/./} in home dirs are ignored. WARNING: Never add directories here
20895 which local users can modify, that may lead to root exploit. Usually
20896 this should be done only if you don't allow shell access for users.
20897 <doc/wiki/Chrooting.txt>.
20898 Defaults to @samp{()}.
20901 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
20902 Default chroot directory for mail processes. This can be overridden
20903 for specific users in user database by giving @samp{/./} in user's home
20904 directory (e.g.@: @samp{/home/./user} chroots into @file{/home}). Note that usually
20905 there is no real need to do chrooting, Dovecot doesn't allow users to
20906 access files outside their mail directory anyway. If your home
20907 directories are prefixed with the chroot directory, append @samp{/.} to
20908 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
20909 Defaults to @samp{""}.
20912 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
20913 UNIX socket path to master authentication server to find users.
20914 This is used by imap (for shared users) and lda.
20915 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
20918 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
20919 Directory where to look up mail plugins.
20920 Defaults to @samp{"/usr/lib/dovecot"}.
20923 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
20924 List of plugins to load for all services. Plugins specific to IMAP,
20925 LDA, etc.@: are added to this list in their own .conf files.
20926 Defaults to @samp{()}.
20929 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
20930 The minimum number of mails in a mailbox before updates are done to
20931 cache file. This allows optimizing Dovecot's behavior to do less disk
20932 writes at the cost of more disk reads.
20933 Defaults to @samp{0}.
20936 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
20937 When IDLE command is running, mailbox is checked once in a while to
20938 see if there are any new mails or other changes. This setting defines
20939 the minimum time to wait between those checks. Dovecot can also use
20940 dnotify, inotify and kqueue to find out immediately when changes
20942 Defaults to @samp{"30 secs"}.
20945 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
20946 Save mails with CR+LF instead of plain LF@. This makes sending those
20947 mails take less CPU, especially with sendfile() syscall with Linux and
20948 FreeBSD@. But it also creates a bit more disk I/O which may just make it
20949 slower. Also note that if other software reads the mboxes/maildirs,
20950 they may handle the extra CRs wrong and cause problems.
20951 Defaults to @samp{#f}.
20954 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
20955 By default LIST command returns all entries in maildir beginning
20956 with a dot. Enabling this option makes Dovecot return only entries
20957 which are directories. This is done by stat()ing each entry, so it
20958 causes more disk I/O.
20959 (For systems setting struct @samp{dirent->d_type} this check is free
20960 and it's done always regardless of this setting).
20961 Defaults to @samp{#f}.
20964 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
20965 When copying a message, do it with hard links whenever possible.
20966 This makes the performance much better, and it's unlikely to have any
20968 Defaults to @samp{#t}.
20971 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
20972 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
20973 directory only when its mtime changes unexpectedly or when we can't find
20974 the mail otherwise.
20975 Defaults to @samp{#f}.
20978 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
20979 Which locking methods to use for locking mbox. There are four
20984 Create <mailbox>.lock file. This is the oldest and most NFS-safe
20985 solution. If you want to use /var/mail/ like directory, the users will
20986 need write access to that directory.
20988 Same as dotlock, but if it fails because of permissions or because there
20989 isn't enough disk space, just skip it.
20991 Use this if possible. Works with NFS too if lockd is used.
20993 May not exist in all systems. Doesn't work with NFS.
20995 May not exist in all systems. Doesn't work with NFS.
20998 You can use multiple locking methods; if you do the order they're declared
20999 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
21000 locking methods as well. Some operating systems don't allow using some of
21001 them simultaneously.
21004 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
21008 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
21009 Maximum time to wait for lock (all of them) before aborting.
21010 Defaults to @samp{"5 mins"}.
21013 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
21014 If dotlock exists but the mailbox isn't modified in any way,
21015 override the lock file after this much time.
21016 Defaults to @samp{"2 mins"}.
21019 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
21020 When mbox changes unexpectedly we have to fully read it to find out
21021 what changed. If the mbox is large this can take a long time. Since
21022 the change is usually just a newly appended mail, it'd be faster to
21023 simply read the new mails. If this setting is enabled, Dovecot does
21024 this but still safely fallbacks to re-reading the whole mbox file
21025 whenever something in mbox isn't how it's expected to be. The only real
21026 downside to this setting is that if some other MUA changes message
21027 flags, Dovecot doesn't notice it immediately. Note that a full sync is
21028 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
21029 Defaults to @samp{#t}.
21032 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
21033 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
21034 EXAMINE, EXPUNGE or CHECK commands. If this is set,
21035 @samp{mbox-dirty-syncs} is ignored.
21036 Defaults to @samp{#f}.
21039 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
21040 Delay writing mbox headers until doing a full write sync (EXPUNGE
21041 and CHECK commands and when closing the mailbox). This is especially
21042 useful for POP3 where clients often delete all mails. The downside is
21043 that our changes aren't immediately visible to other MUAs.
21044 Defaults to @samp{#t}.
21047 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
21048 If mbox size is smaller than this (e.g.@: 100k), don't write index
21049 files. If an index file already exists it's still read, just not
21051 Defaults to @samp{0}.
21054 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
21055 Maximum dbox file size until it's rotated.
21056 Defaults to @samp{10000000}.
21059 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
21060 Maximum dbox file age until it's rotated. Typically in days. Day
21061 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
21063 Defaults to @samp{"1d"}.
21066 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
21067 When creating new mdbox files, immediately preallocate their size to
21068 @samp{mdbox-rotate-size}. This setting currently works only in Linux
21069 with some file systems (ext4, xfs).
21070 Defaults to @samp{#f}.
21073 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
21074 sdbox and mdbox support saving mail attachments to external files,
21075 which also allows single instance storage for them. Other backends
21076 don't support this for now.
21078 WARNING: This feature hasn't been tested much yet. Use at your own risk.
21080 Directory root where to store mail attachments. Disabled, if empty.
21081 Defaults to @samp{""}.
21084 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
21085 Attachments smaller than this aren't saved externally. It's also
21086 possible to write a plugin to disable saving specific attachments
21088 Defaults to @samp{128000}.
21091 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
21092 File system backend to use for saving attachments:
21095 No SiS done by Dovecot (but this might help FS's own deduplication)
21097 SiS with immediate byte-by-byte comparison during saving
21098 @item sis-queue posix
21099 SiS with delayed comparison and deduplication.
21101 Defaults to @samp{"sis posix"}.
21104 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
21105 Hash format to use in attachment filenames. You can add any text and
21106 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
21107 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
21108 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
21109 Defaults to @samp{"%@{sha1@}"}.
21112 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
21114 Defaults to @samp{100}.
21117 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
21119 Defaults to @samp{1000}.
21122 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
21123 Default VSZ (virtual memory size) limit for service processes.
21124 This is mainly intended to catch and kill processes that leak memory
21125 before they eat up everything.
21126 Defaults to @samp{256000000}.
21129 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
21130 Login user is internally used by login processes. This is the most
21131 untrusted user in Dovecot system. It shouldn't have access to anything
21133 Defaults to @samp{"dovenull"}.
21136 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
21137 Internal user is used by unprivileged processes. It should be
21138 separate from login user, so that login processes can't disturb other
21140 Defaults to @samp{"dovecot"}.
21143 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
21144 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
21145 Defaults to @samp{"required"}.
21148 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
21149 PEM encoded X.509 SSL/TLS certificate (public key).
21150 Defaults to @samp{"</etc/dovecot/default.pem"}.
21153 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
21154 PEM encoded SSL/TLS private key. The key is opened before
21155 dropping root privileges, so keep the key file unreadable by anyone but
21157 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
21160 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
21161 If key file is password protected, give the password here.
21162 Alternatively give it when starting dovecot with -p parameter. Since
21163 this file is often world-readable, you may want to place this setting
21164 instead to a different.
21165 Defaults to @samp{""}.
21168 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
21169 PEM encoded trusted certificate authority. Set this only if you
21170 intend to use @samp{ssl-verify-client-cert? #t}. The file should
21171 contain the CA certificate(s) followed by the matching
21172 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
21173 Defaults to @samp{""}.
21176 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
21177 Require that CRL check succeeds for client certificates.
21178 Defaults to @samp{#t}.
21181 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
21182 Request client to send a certificate. If you also want to require
21183 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
21184 Defaults to @samp{#f}.
21187 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
21188 Which field from certificate to use for username. commonName and
21189 x500UniqueIdentifier are the usual choices. You'll also need to set
21190 @samp{auth-ssl-username-from-cert? #t}.
21191 Defaults to @samp{"commonName"}.
21194 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
21195 Minimum SSL protocol version to accept.
21196 Defaults to @samp{"TLSv1"}.
21199 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
21200 SSL ciphers to use.
21201 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
21204 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
21205 SSL crypto device to use, for valid values run "openssl engine".
21206 Defaults to @samp{""}.
21209 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
21210 Address to use when sending rejection mails.
21211 %d expands to recipient domain.
21212 Defaults to @samp{"postmaster@@%d"}.
21215 @deftypevr {@code{dovecot-configuration} parameter} string hostname
21216 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
21217 and in LMTP replies. Default is the system's real hostname@@domain.
21218 Defaults to @samp{""}.
21221 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
21222 If user is over quota, return with temporary failure instead of
21224 Defaults to @samp{#f}.
21227 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
21228 Binary to use for sending mails.
21229 Defaults to @samp{"/usr/sbin/sendmail"}.
21232 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
21233 If non-empty, send mails via this SMTP host[:port] instead of
21235 Defaults to @samp{""}.
21238 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
21239 Subject: header to use for rejection mails. You can use the same
21240 variables as for @samp{rejection-reason} below.
21241 Defaults to @samp{"Rejected: %s"}.
21244 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
21245 Human readable error message for rejection mails. You can use
21258 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
21261 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
21262 Delimiter character between local-part and detail in email
21264 Defaults to @samp{"+"}.
21267 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
21268 Header where the original recipient address (SMTP's RCPT TO:
21269 address) is taken from if not available elsewhere. With dovecot-lda -a
21270 parameter overrides this. A commonly used header for this is
21272 Defaults to @samp{""}.
21275 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
21276 Should saving a mail to a nonexistent mailbox automatically create
21278 Defaults to @samp{#f}.
21281 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
21282 Should automatically created mailboxes be also automatically
21284 Defaults to @samp{#f}.
21287 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
21288 Maximum IMAP command line length. Some clients generate very long
21289 command lines with huge mailboxes, so you may need to raise this if you
21290 get "Too long argument" or "IMAP command line too large" errors
21292 Defaults to @samp{64000}.
21295 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
21296 IMAP logout format string:
21299 total number of bytes read from client
21301 total number of bytes sent to client.
21303 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
21304 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@}"}.
21307 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
21308 Override the IMAP CAPABILITY response. If the value begins with '+',
21309 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
21310 Defaults to @samp{""}.
21313 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
21314 How long to wait between "OK Still here" notifications when client
21316 Defaults to @samp{"2 mins"}.
21319 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
21320 ID field names and values to send to clients. Using * as the value
21321 makes Dovecot use the default value. The following fields have default
21322 values currently: name, version, os, os-version, support-url,
21324 Defaults to @samp{""}.
21327 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
21328 ID fields sent by client to log. * means everything.
21329 Defaults to @samp{""}.
21332 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
21333 Workarounds for various client bugs:
21336 @item delay-newmail
21337 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
21338 CHECK commands. Some clients ignore them otherwise, for example OSX
21339 Mail (<v2.1). Outlook Express breaks more badly though, without this it
21340 may show user "Message no longer in server" errors. Note that OE6
21341 still breaks even with this workaround if synchronization is set to
21344 @item tb-extra-mailbox-sep
21345 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
21346 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
21347 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
21349 @item tb-lsub-flags
21350 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
21351 This makes Thunderbird realize they aren't selectable and show them
21352 greyed out, instead of only later giving "not selectable" popup error.
21354 Defaults to @samp{()}.
21357 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
21358 Host allowed in URLAUTH URLs sent by client. "*" allows all.
21359 Defaults to @samp{""}.
21363 Whew! Lots of configuration options. The nice thing about it though is
21364 that Guix has a complete interface to Dovecot's configuration
21365 language. This allows not only a nice way to declare configurations,
21366 but also offers reflective capabilities as well: users can write code to
21367 inspect and transform configurations from within Scheme.
21369 However, it could be that you just want to get a @code{dovecot.conf} up
21370 and running. In that case, you can pass an
21371 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
21372 @code{dovecot-service}. As its name indicates, an opaque configuration
21373 does not have easy reflective capabilities.
21375 Available @code{opaque-dovecot-configuration} fields are:
21377 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
21378 The dovecot package.
21381 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
21382 The contents of the @code{dovecot.conf}, as a string.
21385 For example, if your @code{dovecot.conf} is just the empty string, you
21386 could instantiate a dovecot service like this:
21389 (dovecot-service #:config
21390 (opaque-dovecot-configuration
21394 @subsubheading OpenSMTPD Service
21396 @deffn {Scheme Variable} opensmtpd-service-type
21397 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
21398 service, whose value should be an @code{opensmtpd-configuration} object
21399 as in this example:
21402 (service opensmtpd-service-type
21403 (opensmtpd-configuration
21404 (config-file (local-file "./my-smtpd.conf"))))
21408 @deftp {Data Type} opensmtpd-configuration
21409 Data type representing the configuration of opensmtpd.
21412 @item @code{package} (default: @var{opensmtpd})
21413 Package object of the OpenSMTPD SMTP server.
21415 @item @code{config-file} (default: @code{%default-opensmtpd-file})
21416 File-like object of the OpenSMTPD configuration file to use. By default
21417 it listens on the loopback network interface, and allows for mail from
21418 users and daemons on the local machine, as well as permitting email to
21419 remote servers. Run @command{man smtpd.conf} for more information.
21424 @subsubheading Exim Service
21426 @cindex mail transfer agent (MTA)
21427 @cindex MTA (mail transfer agent)
21430 @deffn {Scheme Variable} exim-service-type
21431 This is the type of the @uref{https://exim.org, Exim} mail transfer
21432 agent (MTA), whose value should be an @code{exim-configuration} object
21433 as in this example:
21436 (service exim-service-type
21437 (exim-configuration
21438 (config-file (local-file "./my-exim.conf"))))
21442 In order to use an @code{exim-service-type} service you must also have a
21443 @code{mail-aliases-service-type} service present in your
21444 @code{operating-system} (even if it has no aliases).
21446 @deftp {Data Type} exim-configuration
21447 Data type representing the configuration of exim.
21450 @item @code{package} (default: @var{exim})
21451 Package object of the Exim server.
21453 @item @code{config-file} (default: @code{#f})
21454 File-like object of the Exim configuration file to use. If its value is
21455 @code{#f} then use the default configuration file from the package
21456 provided in @code{package}. The resulting configuration file is loaded
21457 after setting the @code{exim_user} and @code{exim_group} configuration
21463 @subsubheading Getmail service
21468 @deffn {Scheme Variable} getmail-service-type
21469 This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
21470 mail retriever, whose value should be an @code{getmail-configuration}.
21473 Available @code{getmail-configuration} fields are:
21475 @deftypevr {@code{getmail-configuration} parameter} symbol name
21476 A symbol to identify the getmail service.
21478 Defaults to @samp{"unset"}.
21482 @deftypevr {@code{getmail-configuration} parameter} package package
21483 The getmail package to use.
21487 @deftypevr {@code{getmail-configuration} parameter} string user
21488 The user to run getmail as.
21490 Defaults to @samp{"getmail"}.
21494 @deftypevr {@code{getmail-configuration} parameter} string group
21495 The group to run getmail as.
21497 Defaults to @samp{"getmail"}.
21501 @deftypevr {@code{getmail-configuration} parameter} string directory
21502 The getmail directory to use.
21504 Defaults to @samp{"/var/lib/getmail/default"}.
21508 @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
21509 The getmail configuration file to use.
21511 Available @code{getmail-configuration-file} fields are:
21513 @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
21514 What mail account to retrieve mail from, and how to access that account.
21516 Available @code{getmail-retriever-configuration} fields are:
21518 @deftypevr {@code{getmail-retriever-configuration} parameter} string type
21519 The type of mail retriever to use. Valid values include @samp{passwd}
21522 Defaults to @samp{"SimpleIMAPSSLRetriever"}.
21526 @deftypevr {@code{getmail-retriever-configuration} parameter} string server
21527 Username to login to the mail server with.
21529 Defaults to @samp{unset}.
21533 @deftypevr {@code{getmail-retriever-configuration} parameter} string username
21534 Username to login to the mail server with.
21536 Defaults to @samp{unset}.
21540 @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
21541 Port number to connect to.
21543 Defaults to @samp{#f}.
21547 @deftypevr {@code{getmail-retriever-configuration} parameter} string password
21548 Override fields from passwd.
21550 Defaults to @samp{""}.
21554 @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
21555 Override fields from passwd.
21557 Defaults to @samp{()}.
21561 @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
21562 PEM-formatted key file to use for the TLS negotiation.
21564 Defaults to @samp{""}.
21568 @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
21569 PEM-formatted certificate file to use for the TLS negotiation.
21571 Defaults to @samp{""}.
21575 @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
21576 CA certificates to use.
21578 Defaults to @samp{""}.
21582 @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
21583 Extra retriever parameters.
21585 Defaults to @samp{()}.
21591 @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
21592 What to do with retrieved messages.
21594 Available @code{getmail-destination-configuration} fields are:
21596 @deftypevr {@code{getmail-destination-configuration} parameter} string type
21597 The type of mail destination. Valid values include @samp{Maildir},
21598 @samp{Mboxrd} and @samp{MDA_external}.
21600 Defaults to @samp{unset}.
21604 @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
21605 The path option for the mail destination. The behaviour depends on the
21608 Defaults to @samp{""}.
21612 @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
21613 Extra destination parameters
21615 Defaults to @samp{()}.
21621 @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
21624 Available @code{getmail-options-configuration} fields are:
21626 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
21627 If set to @samp{0}, getmail will only print warnings and errors. A
21628 value of @samp{1} means that messages will be printed about retrieving
21629 and deleting messages. If set to @samp{2}, getmail will print messages
21630 about each of it's actions.
21632 Defaults to @samp{1}.
21636 @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
21637 If true, getmail will retrieve all available messages. Otherwise it
21638 will only retrieve messages it hasn't seen previously.
21640 Defaults to @samp{#t}.
21644 @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
21645 If set to true, messages will be deleted from the server after
21646 retrieving and successfully delivering them. Otherwise, messages will
21647 be left on the server.
21649 Defaults to @samp{#f}.
21653 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
21654 Getmail will delete messages this number of days after seeing them, if
21655 they have been delivered. This means messages will be left on the
21656 server this number of days after delivering them. A value of @samp{0}
21657 disabled this feature.
21659 Defaults to @samp{0}.
21663 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
21664 Delete messages larger than this of bytes after retrieving them, even if
21665 the delete and delete-after options are disabled. A value of @samp{0}
21666 disables this feature.
21668 Defaults to @samp{0}.
21672 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
21673 Retrieve messages totalling up to this number of bytes before closing
21674 the session with the server. A value of @samp{0} disables this feature.
21676 Defaults to @samp{0}.
21680 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
21681 Don't retrieve messages larger than this number of bytes. A value of
21682 @samp{0} disables this feature.
21684 Defaults to @samp{0}.
21688 @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
21689 If true, getmail will add a Delivered-To header to messages.
21691 Defaults to @samp{#t}.
21695 @deftypevr {@code{getmail-options-configuration} parameter} boolean received
21696 If set, getmail adds a Received header to the messages.
21698 Defaults to @samp{#t}.
21702 @deftypevr {@code{getmail-options-configuration} parameter} string message-log
21703 Getmail will record a log of its actions to the named file. A value of
21704 @samp{""} disables this feature.
21706 Defaults to @samp{""}.
21710 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
21711 If true, getmail will record a log of its actions using the system
21714 Defaults to @samp{#f}.
21718 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
21719 If true, getmail will log information about messages not retrieved and
21720 the reason for not retrieving them, as well as starting and ending
21723 Defaults to @samp{#f}.
21727 @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
21728 Extra options to include.
21730 Defaults to @samp{()}.
21738 @deftypevr {@code{getmail-configuration} parameter} list idle
21739 A list of mailboxes that getmail should wait on the server for new mail
21740 notifications. This depends on the server supporting the IDLE
21743 Defaults to @samp{()}.
21747 @deftypevr {@code{getmail-configuration} parameter} list environment-variables
21748 Environment variables to set for getmail.
21750 Defaults to @samp{()}.
21754 @subsubheading Mail Aliases Service
21756 @cindex email aliases
21757 @cindex aliases, for email addresses
21759 @deffn {Scheme Variable} mail-aliases-service-type
21760 This is the type of the service which provides @code{/etc/aliases},
21761 specifying how to deliver mail to users on this system.
21764 (service mail-aliases-service-type
21765 '(("postmaster" "bob")
21766 ("bob" "bob@@example.com" "bob@@example2.com")))
21770 The configuration for a @code{mail-aliases-service-type} service is an
21771 association list denoting how to deliver mail that comes to this
21772 system. Each entry is of the form @code{(alias addresses ...)}, with
21773 @code{alias} specifying the local alias and @code{addresses} specifying
21774 where to deliver this user's mail.
21776 The aliases aren't required to exist as users on the local system. In
21777 the above example, there doesn't need to be a @code{postmaster} entry in
21778 the @code{operating-system}'s @code{user-accounts} in order to deliver
21779 the @code{postmaster} mail to @code{bob} (which subsequently would
21780 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
21782 @subsubheading GNU Mailutils IMAP4 Daemon
21783 @cindex GNU Mailutils IMAP4 Daemon
21785 @deffn {Scheme Variable} imap4d-service-type
21786 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
21787 mailutils, GNU Mailutils Manual}), whose value should be an
21788 @code{imap4d-configuration} object as in this example:
21791 (service imap4d-service-type
21792 (imap4d-configuration
21793 (config-file (local-file "imap4d.conf"))))
21797 @deftp {Data Type} imap4d-configuration
21798 Data type representing the configuration of @command{imap4d}.
21801 @item @code{package} (default: @code{mailutils})
21802 The package that provides @command{imap4d}.
21804 @item @code{config-file} (default: @code{%default-imap4d-config-file})
21805 File-like object of the configuration file to use, by default it will listen
21806 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
21807 Mailutils Manual}, for details.
21812 @subsubheading Radicale Service
21816 @deffn {Scheme Variable} radicale-service-type
21817 This is the type of the @uref{https://radicale.org, Radicale} CalDAV/CardDAV
21818 server whose value should be a @code{radicale-configuration}.
21821 @deftp {Data Type} radicale-configuration
21822 Data type representing the configuration of @command{radicale}.
21825 @item @code{package} (default: @code{radicale})
21826 The package that provides @command{radicale}.
21828 @item @code{config-file} (default: @code{%default-radicale-config-file})
21829 File-like object of the configuration file to use, by default it will listen
21830 on TCP port 5232 of @code{localhost} and use the @code{htpasswd} file at
21831 @file{/var/lib/radicale/users} with no (@code{plain}) encryption.
21836 @node Messaging Services
21837 @subsection Messaging Services
21842 The @code{(gnu services messaging)} module provides Guix service
21843 definitions for messaging services. Currently it provides the following
21846 @subsubheading Prosody Service
21848 @deffn {Scheme Variable} prosody-service-type
21849 This is the type for the @uref{https://prosody.im, Prosody XMPP
21850 communication server}. Its value must be a @code{prosody-configuration}
21851 record as in this example:
21854 (service prosody-service-type
21855 (prosody-configuration
21856 (modules-enabled (cons* "groups" "mam" %default-modules-enabled))
21859 (int-component-configuration
21860 (hostname "conference.example.net")
21862 (mod-muc (mod-muc-configuration)))))
21865 (virtualhost-configuration
21866 (domain "example.net"))))))
21869 See below for details about @code{prosody-configuration}.
21873 By default, Prosody does not need much configuration. Only one
21874 @code{virtualhosts} field is needed: it specifies the domain you wish
21877 You can perform various sanity checks on the generated configuration
21878 with the @code{prosodyctl check} command.
21880 Prosodyctl will also help you to import certificates from the
21881 @code{letsencrypt} directory so that the @code{prosody} user can access
21882 them. See @url{https://prosody.im/doc/letsencrypt}.
21885 prosodyctl --root cert import /etc/letsencrypt/live
21888 The available configuration parameters follow. Each parameter
21889 definition is preceded by its type; for example, @samp{string-list foo}
21890 indicates that the @code{foo} parameter should be specified as a list of
21891 strings. Types starting with @code{maybe-} denote parameters that won't
21892 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
21894 There is also a way to specify the configuration as a string, if you
21895 have an old @code{prosody.cfg.lua} file that you want to port over from
21896 some other system; see the end for more details.
21898 The @code{file-object} type designates either a file-like object
21899 (@pxref{G-Expressions, file-like objects}) or a file name.
21901 @c The following documentation was initially generated by
21902 @c (generate-documentation) in (gnu services messaging). Manually maintained
21903 @c documentation is better, so we shouldn't hesitate to edit below as
21904 @c needed. However if the change you want to make to this documentation
21905 @c can be done in an automated way, it's probably easier to change
21906 @c (generate-documentation) than to make it below and have to deal with
21907 @c the churn as Prosody updates.
21909 Available @code{prosody-configuration} fields are:
21911 @deftypevr {@code{prosody-configuration} parameter} package prosody
21912 The Prosody package.
21915 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
21916 Location of the Prosody data storage directory. See
21917 @url{https://prosody.im/doc/configure}.
21918 Defaults to @samp{"/var/lib/prosody"}.
21921 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
21922 Additional plugin directories. They are searched in all the specified
21923 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
21924 Defaults to @samp{()}.
21927 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
21928 Every virtual host and component needs a certificate so that clients and
21929 servers can securely verify its identity. Prosody will automatically load
21930 certificates/keys from the directory specified here.
21931 Defaults to @samp{"/etc/prosody/certs"}.
21934 @deftypevr {@code{prosody-configuration} parameter} string-list admins
21935 This is a list of accounts that are admins for the server. Note that you
21936 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
21937 @url{https://prosody.im/doc/creating_accounts}.
21938 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
21939 Defaults to @samp{()}.
21942 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
21943 Enable use of libevent for better performance under high load. See
21944 @url{https://prosody.im/doc/libevent}.
21945 Defaults to @samp{#f}.
21948 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
21949 This is the list of modules Prosody will load on startup. It looks for
21950 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
21951 Documentation on modules can be found at:
21952 @url{https://prosody.im/doc/modules}.
21953 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
21956 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
21957 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
21958 should you want to disable them then add them to this list.
21959 Defaults to @samp{()}.
21962 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
21963 Path to a text file where the shared groups are defined. If this path is
21964 empty then @samp{mod_groups} does nothing. See
21965 @url{https://prosody.im/doc/modules/mod_groups}.
21966 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
21969 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
21970 Disable account creation by default, for security. See
21971 @url{https://prosody.im/doc/creating_accounts}.
21972 Defaults to @samp{#f}.
21975 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
21976 These are the SSL/TLS-related settings. Most of them are disabled so to
21977 use Prosody's defaults. If you do not completely understand these options, do
21978 not add them to your config, it is easy to lower the security of your server
21979 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
21981 Available @code{ssl-configuration} fields are:
21983 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
21984 This determines what handshake to use.
21987 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
21988 Path to your private key file.
21991 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
21992 Path to your certificate file.
21995 @deftypevr {@code{ssl-configuration} parameter} file-object capath
21996 Path to directory containing root certificates that you wish Prosody to
21997 trust when verifying the certificates of remote servers.
21998 Defaults to @samp{"/etc/ssl/certs"}.
22001 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
22002 Path to a file containing root certificates that you wish Prosody to trust.
22003 Similar to @code{capath} but with all certificates concatenated together.
22006 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
22007 A list of verification options (these mostly map to OpenSSL's
22008 @code{set_verify()} flags).
22011 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
22012 A list of general options relating to SSL/TLS@. These map to OpenSSL's
22013 @code{set_options()}. For a full list of options available in LuaSec, see the
22017 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
22018 How long a chain of certificate authorities to check when looking for a
22019 trusted root certificate.
22022 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
22023 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
22024 clients, and in what order.
22027 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
22028 A path to a file containing parameters for Diffie-Hellman key exchange. You
22029 can create such a file with:
22030 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
22033 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
22034 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
22035 @samp{"secp384r1"}.
22038 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
22039 A list of ``extra'' verification options.
22042 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
22043 Password for encrypted private keys.
22048 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
22049 Whether to force all client-to-server connections to be encrypted or not.
22050 See @url{https://prosody.im/doc/modules/mod_tls}.
22051 Defaults to @samp{#f}.
22054 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
22055 Set of mechanisms that will never be offered. See
22056 @url{https://prosody.im/doc/modules/mod_saslauth}.
22057 Defaults to @samp{("DIGEST-MD5")}.
22060 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
22061 Whether to force all server-to-server connections to be encrypted or not.
22062 See @url{https://prosody.im/doc/modules/mod_tls}.
22063 Defaults to @samp{#f}.
22066 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
22067 Whether to require encryption and certificate authentication. This
22068 provides ideal security, but requires servers you communicate with to support
22069 encryption AND present valid, trusted certificates. See
22070 @url{https://prosody.im/doc/s2s#security}.
22071 Defaults to @samp{#f}.
22074 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
22075 Many servers don't support encryption or have invalid or self-signed
22076 certificates. You can list domains here that will not be required to
22077 authenticate using certificates. They will be authenticated using DNS@. See
22078 @url{https://prosody.im/doc/s2s#security}.
22079 Defaults to @samp{()}.
22082 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
22083 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
22084 valid certificates for some domains by specifying a list here. See
22085 @url{https://prosody.im/doc/s2s#security}.
22086 Defaults to @samp{()}.
22089 @deftypevr {@code{prosody-configuration} parameter} string authentication
22090 Select the authentication backend to use. The default provider stores
22091 passwords in plaintext and uses Prosody's configured data storage to store the
22092 authentication data. If you do not trust your server please see
22093 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
22094 about using the hashed backend. See also
22095 @url{https://prosody.im/doc/authentication}
22096 Defaults to @samp{"internal_plain"}.
22099 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
22100 Set logging options. Advanced logging configuration is not yet supported
22101 by the Prosody service. See @url{https://prosody.im/doc/logging}.
22102 Defaults to @samp{"*syslog"}.
22105 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
22106 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
22107 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
22110 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
22111 Maximum allowed size of the HTTP body (in bytes).
22114 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
22115 Some modules expose their own URL in various ways. This URL is built
22116 from the protocol, host and port used. If Prosody sits behind a proxy, the
22117 public URL will be @code{http-external-url} instead. See
22118 @url{https://prosody.im/doc/http#external_url}.
22121 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
22122 A host in Prosody is a domain on which user accounts can be created. For
22123 example if you want your users to have addresses like
22124 @samp{"john.smith@@example.com"} then you need to add a host
22125 @samp{"example.com"}. All options in this list will apply only to this host.
22127 Note: the name @emph{virtual} host is used in configuration to avoid confusion with
22128 the actual physical host that Prosody is installed on. A single Prosody
22129 instance can serve many domains, each one defined as a VirtualHost entry in
22130 Prosody's configuration. Conversely a server that hosts a single domain would
22131 have just one VirtualHost entry.
22133 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
22135 Available @code{virtualhost-configuration} fields are:
22137 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:
22138 @deftypevr {@code{virtualhost-configuration} parameter} string domain
22139 Domain you wish Prosody to serve.
22144 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
22145 Components are extra services on a server which are available to clients,
22146 usually on a subdomain of the main server (such as
22147 @samp{"mycomponent.example.com"}). Example components might be chatroom
22148 servers, user directories, or gateways to other protocols.
22150 Internal components are implemented with Prosody-specific plugins. To add an
22151 internal component, you simply fill the hostname field, and the plugin you wish
22152 to use for the component.
22154 See @url{https://prosody.im/doc/components}.
22155 Defaults to @samp{()}.
22157 Available @code{int-component-configuration} fields are:
22159 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:
22160 @deftypevr {@code{int-component-configuration} parameter} string hostname
22161 Hostname of the component.
22164 @deftypevr {@code{int-component-configuration} parameter} string plugin
22165 Plugin you wish to use for the component.
22168 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
22169 Multi-user chat (MUC) is Prosody's module for allowing you to create
22170 hosted chatrooms/conferences for XMPP users.
22172 General information on setting up and using multi-user chatrooms can be found
22173 in the ``Chatrooms'' documentation (@url{https://prosody.im/doc/chatrooms}),
22174 which you should read if you are new to XMPP chatrooms.
22176 See also @url{https://prosody.im/doc/modules/mod_muc}.
22178 Available @code{mod-muc-configuration} fields are:
22180 @deftypevr {@code{mod-muc-configuration} parameter} string name
22181 The name to return in service discovery responses.
22182 Defaults to @samp{"Prosody Chatrooms"}.
22185 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
22186 If @samp{#t}, this will only allow admins to create new chatrooms.
22187 Otherwise anyone can create a room. The value @samp{"local"} restricts room
22188 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
22189 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
22190 restricts to service administrators only.
22191 Defaults to @samp{#f}.
22194 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
22195 Maximum number of history messages that will be sent to the member that has
22196 just joined the room.
22197 Defaults to @samp{20}.
22204 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
22205 External components use XEP-0114, which most standalone components
22206 support. To add an external component, you simply fill the hostname field. See
22207 @url{https://prosody.im/doc/components}.
22208 Defaults to @samp{()}.
22210 Available @code{ext-component-configuration} fields are:
22212 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:
22213 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
22214 Password which the component will use to log in.
22217 @deftypevr {@code{ext-component-configuration} parameter} string hostname
22218 Hostname of the component.
22223 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
22224 Port(s) Prosody listens on for component connections.
22225 Defaults to @samp{(5347)}.
22228 @deftypevr {@code{prosody-configuration} parameter} string component-interface
22229 Interface Prosody listens on for component connections.
22230 Defaults to @samp{"127.0.0.1"}.
22233 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
22234 Raw content that will be added to the configuration file.
22237 It could be that you just want to get a @code{prosody.cfg.lua}
22238 up and running. In that case, you can pass an
22239 @code{opaque-prosody-configuration} record as the value of
22240 @code{prosody-service-type}. As its name indicates, an opaque configuration
22241 does not have easy reflective capabilities.
22242 Available @code{opaque-prosody-configuration} fields are:
22244 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
22245 The prosody package.
22248 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
22249 The contents of the @code{prosody.cfg.lua} to use.
22252 For example, if your @code{prosody.cfg.lua} is just the empty
22253 string, you could instantiate a prosody service like this:
22256 (service prosody-service-type
22257 (opaque-prosody-configuration
22258 (prosody.cfg.lua "")))
22261 @c end of Prosody auto-generated documentation
22263 @subsubheading BitlBee Service
22265 @cindex IRC (Internet Relay Chat)
22266 @cindex IRC gateway
22267 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
22268 interface to a variety of messaging protocols such as XMPP.
22270 @defvr {Scheme Variable} bitlbee-service-type
22271 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
22272 gateway daemon. Its value is a @code{bitlbee-configuration} (see
22275 To have BitlBee listen on port 6667 on localhost, add this line to your
22279 (service bitlbee-service-type)
22283 @deftp {Data Type} bitlbee-configuration
22284 This is the configuration for BitlBee, with the following fields:
22287 @item @code{interface} (default: @code{"127.0.0.1"})
22288 @itemx @code{port} (default: @code{6667})
22289 Listen on the network interface corresponding to the IP address
22290 specified in @var{interface}, on @var{port}.
22292 When @var{interface} is @code{127.0.0.1}, only local clients can
22293 connect; when it is @code{0.0.0.0}, connections can come from any
22294 networking interface.
22296 @item @code{bitlbee} (default: @code{bitlbee})
22297 The BitlBee package to use.
22299 @item @code{plugins} (default: @code{'()})
22300 List of plugin packages to use---e.g., @code{bitlbee-discord}.
22302 @item @code{extra-settings} (default: @code{""})
22303 Configuration snippet added as-is to the BitlBee configuration file.
22307 @subsubheading Quassel Service
22309 @cindex IRC (Internet Relay Chat)
22310 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
22311 meaning that one or more clients can attach to and detach from the
22314 @defvr {Scheme Variable} quassel-service-type
22315 This is the service type for the @url{https://quassel-irc.org/,Quassel}
22316 IRC backend daemon. Its value is a @code{quassel-configuration}
22320 @deftp {Data Type} quassel-configuration
22321 This is the configuration for Quassel, with the following fields:
22324 @item @code{quassel} (default: @code{quassel})
22325 The Quassel package to use.
22327 @item @code{interface} (default: @code{"::,0.0.0.0"})
22328 @item @code{port} (default: @code{4242})
22329 Listen on the network interface(s) corresponding to the IPv4 or IPv6
22330 interfaces specified in the comma delimited @var{interface}, on
22333 @item @code{loglevel} (default: @code{"Info"})
22334 The level of logging desired. Accepted values are Debug, Info, Warning
22339 @node Telephony Services
22340 @subsection Telephony Services
22342 @cindex Murmur (VoIP server)
22343 @cindex VoIP server
22344 This section describes how to set up and run a Murmur server. Murmur is
22345 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
22348 @deftp {Data Type} murmur-configuration
22349 The service type for the Murmur server. An example configuration can
22353 (service murmur-service-type
22354 (murmur-configuration
22356 "Welcome to this Mumble server running on Guix!")
22357 (cert-required? #t) ;disallow text password logins
22358 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
22359 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
22362 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
22363 password with the command that is printed during the activation phase.
22365 It is recommended to register a normal Mumble user account
22366 and grant it admin or moderator rights.
22367 You can use the @code{mumble} client to
22368 login as new normal user, register yourself, and log out.
22369 For the next step login with the name @code{SuperUser} use
22370 the @code{SuperUser} password that you set previously,
22371 and grant your newly registered mumble user administrator or moderator
22372 rights and create some channels.
22374 Available @code{murmur-configuration} fields are:
22377 @item @code{package} (default: @code{mumble})
22378 Package that contains @code{bin/murmurd}.
22380 @item @code{user} (default: @code{"murmur"})
22381 User who will run the Murmur server.
22383 @item @code{group} (default: @code{"murmur"})
22384 Group of the user who will run the murmur server.
22386 @item @code{port} (default: @code{64738})
22387 Port on which the server will listen.
22389 @item @code{welcome-text} (default: @code{""})
22390 Welcome text sent to clients when they connect.
22392 @item @code{server-password} (default: @code{""})
22393 Password the clients have to enter in order to connect.
22395 @item @code{max-users} (default: @code{100})
22396 Maximum of users that can be connected to the server at once.
22398 @item @code{max-user-bandwidth} (default: @code{#f})
22399 Maximum voice traffic a user can send per second.
22401 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
22402 File name of the sqlite database.
22403 The service's user will become the owner of the directory.
22405 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
22406 File name of the log file.
22407 The service's user will become the owner of the directory.
22409 @item @code{autoban-attempts} (default: @code{10})
22410 Maximum number of logins a user can make in @code{autoban-timeframe}
22411 without getting auto banned for @code{autoban-time}.
22413 @item @code{autoban-timeframe} (default: @code{120})
22414 Timeframe for autoban in seconds.
22416 @item @code{autoban-time} (default: @code{300})
22417 Amount of time in seconds for which a client gets banned
22418 when violating the autoban limits.
22420 @item @code{opus-threshold} (default: @code{100})
22421 Percentage of clients that need to support opus
22422 before switching over to opus audio codec.
22424 @item @code{channel-nesting-limit} (default: @code{10})
22425 How deep channels can be nested at maximum.
22427 @item @code{channelname-regex} (default: @code{#f})
22428 A string in form of a Qt regular expression that channel names must conform to.
22430 @item @code{username-regex} (default: @code{#f})
22431 A string in form of a Qt regular expression that user names must conform to.
22433 @item @code{text-message-length} (default: @code{5000})
22434 Maximum size in bytes that a user can send in one text chat message.
22436 @item @code{image-message-length} (default: @code{(* 128 1024)})
22437 Maximum size in bytes that a user can send in one image message.
22439 @item @code{cert-required?} (default: @code{#f})
22440 If it is set to @code{#t} clients that use weak password authentication
22441 will not be accepted. Users must have completed the certificate wizard to join.
22443 @item @code{remember-channel?} (default: @code{#f})
22444 Should murmur remember the last channel each user was in when they disconnected
22445 and put them into the remembered channel when they rejoin.
22447 @item @code{allow-html?} (default: @code{#f})
22448 Should html be allowed in text messages, user comments, and channel descriptions.
22450 @item @code{allow-ping?} (default: @code{#f})
22451 Setting to true exposes the current user count, the maximum user count, and
22452 the server's maximum bandwidth per client to unauthenticated users. In the
22453 Mumble client, this information is shown in the Connect dialog.
22455 Disabling this setting will prevent public listing of the server.
22457 @item @code{bonjour?} (default: @code{#f})
22458 Should the server advertise itself in the local network through the bonjour protocol.
22460 @item @code{send-version?} (default: @code{#f})
22461 Should the murmur server version be exposed in ping requests.
22463 @item @code{log-days} (default: @code{31})
22464 Murmur also stores logs in the database, which are accessible via RPC.
22465 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
22466 or -1 to disable logging to the database.
22468 @item @code{obfuscate-ips?} (default: @code{#t})
22469 Should logged ips be obfuscated to protect the privacy of users.
22471 @item @code{ssl-cert} (default: @code{#f})
22472 File name of the SSL/TLS certificate used for encrypted connections.
22475 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
22477 @item @code{ssl-key} (default: @code{#f})
22478 Filepath to the ssl private key used for encrypted connections.
22480 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
22483 @item @code{ssl-dh-params} (default: @code{#f})
22484 File name of a PEM-encoded file with Diffie-Hellman parameters
22485 for the SSL/TLS encryption. Alternatively you set it to
22486 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
22487 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
22489 @item @code{ssl-ciphers} (default: @code{#f})
22490 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
22493 This option is specified using
22494 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
22495 OpenSSL cipher list notation}.
22497 It is recommended that you try your cipher string using 'openssl ciphers <string>'
22498 before setting it here, to get a feel for which cipher suites you will get.
22499 After setting this option, it is recommend that you inspect your Murmur log
22500 to ensure that Murmur is using the cipher suites that you expected it to.
22502 Note: Changing this option may impact the backwards compatibility of your
22503 Murmur server, and can remove the ability for older Mumble clients to be able
22506 @item @code{public-registration} (default: @code{#f})
22507 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
22509 You can optionally register your server in the public server list that the
22510 @code{mumble} client shows on startup.
22511 You cannot register your server if you have set a @code{server-password},
22512 or set @code{allow-ping} to @code{#f}.
22514 It might take a few hours until it shows up in the public list.
22516 @item @code{file} (default: @code{#f})
22517 Optional alternative override for this configuration.
22521 @deftp {Data Type} murmur-public-registration-configuration
22522 Configuration for public registration of a murmur service.
22526 This is a display name for your server. Not to be confused with the hostname.
22528 @item @code{password}
22529 A password to identify your registration.
22530 Subsequent updates will need the same password. Don't lose your password.
22533 This should be a @code{http://} or @code{https://} link to your web
22536 @item @code{hostname} (default: @code{#f})
22537 By default your server will be listed by its IP address.
22538 If it is set your server will be linked by this host name instead.
22544 @node File-Sharing Services
22545 @subsection File-Sharing Services
22547 The @code{(gnu services file-sharing)} module provides services that
22548 assist with transferring files over peer-to-peer file-sharing networks.
22550 @subsubheading Transmission Daemon Service
22552 @uref{https://transmissionbt.com/, Transmission} is a flexible
22553 BitTorrent client that offers a variety of graphical and command-line
22554 interfaces. A @code{transmission-daemon-service-type} service provides
22555 Transmission's headless variant, @command{transmission-daemon}, as a
22556 system service, allowing users to share files via BitTorrent even when
22557 they are not logged in.
22559 @deffn {Scheme Variable} transmission-daemon-service-type
22560 The service type for the Transmission Daemon BitTorrent client. Its
22561 value must be a @code{transmission-daemon-configuration} object as in
22565 (service transmission-daemon-service-type
22566 (transmission-daemon-configuration
22567 ;; Restrict access to the RPC ("control") interface
22568 (rpc-authentication-required? #t)
22569 (rpc-username "transmission")
22571 (transmission-password-hash
22572 "transmission" ; desired password
22573 "uKd1uMs9")) ; arbitrary salt value
22575 ;; Accept requests from this and other hosts on the
22577 (rpc-whitelist-enabled? #t)
22578 (rpc-whitelist '("::1" "127.0.0.1" "192.168.0.*"))
22580 ;; Limit bandwidth use during work hours
22581 (alt-speed-down (* 1024 2)) ; 2 MB/s
22582 (alt-speed-up 512) ; 512 kB/s
22584 (alt-speed-time-enabled? #t)
22585 (alt-speed-time-day 'weekdays)
22586 (alt-speed-time-begin
22587 (+ (* 60 8) 30)) ; 8:30 am
22588 (alt-speed-time-end
22589 (+ (* 60 (+ 12 5)) 30)))) ; 5:30 pm
22593 Once the service is started, users can interact with the daemon through
22594 its Web interface (at @code{http://localhost:9091/}) or by using the
22595 @command{transmission-remote} command-line tool, available in the
22596 @code{transmission} package. (Emacs users may want to also consider the
22597 @code{emacs-transmission} package.) Both communicate with the daemon
22598 through its remote procedure call (RPC) interface, which by default is
22599 available to all users on the system; you may wish to change this by
22600 assigning values to the @code{rpc-authentication-required?},
22601 @code{rpc-username} and @code{rpc-password} settings, as shown in the
22602 example above and documented further below.
22604 The value for @code{rpc-password} must be a password hash of the type
22605 generated and used by Transmission clients. This can be copied verbatim
22606 from an existing @file{settings.json} file, if another Transmission
22607 client is already being used. Otherwise, the
22608 @code{transmission-password-hash} and @code{transmission-random-salt}
22609 procedures provided by this module can be used to obtain a suitable hash
22612 @deffn {Scheme Procedure} transmission-password-hash @var{password} @var{salt}
22613 Returns a string containing the result of hashing @var{password}
22614 together with @var{salt}, in the format recognized by Transmission
22615 clients for their @code{rpc-password} configuration setting.
22617 @var{salt} must be an eight-character string. The
22618 @code{transmission-random-salt} procedure can be used to generate a
22619 suitable salt value at random.
22622 @deffn {Scheme Procedure} transmission-random-salt
22623 Returns a string containing a random, eight-character salt value of the
22624 type generated and used by Transmission clients, suitable for passing to
22625 the @code{transmission-password-hash} procedure.
22628 These procedures are accessible from within a Guile REPL started with
22629 the @command{guix repl} command (@pxref{Invoking guix repl}). This is
22630 useful for obtaining a random salt value to provide as the second
22631 parameter to `transmission-password-hash`, as in this example session:
22635 scheme@@(guix-user)> ,use (gnu services file-sharing)
22636 scheme@@(guix-user)> (transmission-random-salt)
22640 Alternatively, a complete password hash can generated in a single step:
22643 scheme@@(guix-user)> (transmission-password-hash "transmission"
22644 (transmission-random-salt))
22645 $2 = "@{c8bbc6d1740cd8dc819a6e25563b67812c1c19c9VtFPfdsX"
22648 The resulting string can be used as-is for the value of
22649 @code{rpc-password}, allowing the password to be kept hidden even in the
22650 operating-system configuration.
22652 Torrent files downloaded by the daemon are directly accessible only to
22653 users in the ``transmission'' user group, who receive read-only access
22654 to the directory specified by the @code{download-dir} configuration
22655 setting (and also the directory specified by @code{incomplete-dir}, if
22656 @code{incomplete-dir-enabled?} is @code{#t}). Downloaded files can be
22657 moved to another directory or deleted altogether using
22658 @command{transmission-remote} with its @code{--move} and
22659 @code{--remove-and-delete} options.
22661 If the @code{watch-dir-enabled?} setting is set to @code{#t}, users in
22662 the ``transmission'' group are able also to place @file{.torrent} files
22663 in the directory specified by @code{watch-dir} to have the corresponding
22664 torrents added by the daemon. (The @code{trash-original-torrent-files?}
22665 setting controls whether the daemon deletes these files after processing
22668 Some of the daemon's configuration settings can be changed temporarily
22669 by @command{transmission-remote} and similar tools. To undo these
22670 changes, use the service's @code{reload} action to have the daemon
22671 reload its settings from disk:
22674 # herd reload transmission-daemon
22677 The full set of available configuration settings is defined by the
22678 @code{transmission-daemon-configuration} data type.
22680 @deftp {Data Type} transmission-daemon-configuration
22681 The data type representing configuration settings for Transmission
22682 Daemon. These correspond directly to the settings recognized by
22683 Transmission clients in their @file{settings.json} file.
22686 @c The following documentation was initially generated by
22687 @c (generate-transmission-daemon-documentation) in (gnu services
22688 @c file-sharing). Manually maintained documentation is better, so we
22689 @c shouldn't hesitate to edit below as needed. However if the change
22690 @c you want to make to this documentation can be done in an automated
22691 @c way, it's probably easier to change (generate-documentation) than to
22692 @c make it below and have to deal with the churn as Transmission Daemon
22695 @c %start of fragment
22697 Available @code{transmission-daemon-configuration} fields are:
22699 @deftypevr {@code{transmission-daemon-configuration} parameter} package transmission
22700 The Transmission package to use.
22704 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer stop-wait-period
22705 The period, in seconds, to wait when stopping the service for
22706 @command{transmission-daemon} to exit before killing its process. This
22707 allows the daemon time to complete its housekeeping and send a final
22708 update to trackers as it shuts down. On slow hosts, or hosts with a
22709 slow network connection, this value may need to be increased.
22711 Defaults to @samp{10}.
22715 @deftypevr {@code{transmission-daemon-configuration} parameter} string download-dir
22716 The directory to which torrent files are downloaded.
22718 Defaults to @samp{"/var/lib/transmission-daemon/downloads"}.
22722 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean incomplete-dir-enabled?
22723 If @code{#t}, files will be held in @code{incomplete-dir} while their
22724 torrent is being downloaded, then moved to @code{download-dir} once the
22725 torrent is complete. Otherwise, files for all torrents (including those
22726 still being downloaded) will be placed in @code{download-dir}.
22728 Defaults to @samp{#f}.
22732 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string incomplete-dir
22733 The directory in which files from incompletely downloaded torrents will
22734 be held when @code{incomplete-dir-enabled?} is @code{#t}.
22736 Defaults to @samp{disabled}.
22740 @deftypevr {@code{transmission-daemon-configuration} parameter} umask umask
22741 The file mode creation mask used for downloaded files. (See the
22742 @command{umask} man page for more information.)
22744 Defaults to @samp{18}.
22748 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rename-partial-files?
22749 When @code{#t}, ``.part'' is appended to the name of partially
22752 Defaults to @samp{#t}.
22756 @deftypevr {@code{transmission-daemon-configuration} parameter} preallocation-mode preallocation
22757 The mode by which space should be preallocated for downloaded files, one
22758 of @code{none}, @code{fast} (or @code{sparse}) and @code{full}.
22759 Specifying @code{full} will minimize disk fragmentation at a cost to
22760 file-creation speed.
22762 Defaults to @samp{fast}.
22766 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean watch-dir-enabled?
22767 If @code{#t}, the directory specified by @code{watch-dir} will be
22768 watched for new @file{.torrent} files and the torrents they describe
22769 added automatically (and the original files removed, if
22770 @code{trash-original-torrent-files?} is @code{#t}).
22772 Defaults to @samp{#f}.
22776 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string watch-dir
22777 The directory to be watched for @file{.torrent} files indicating new
22778 torrents to be added, when @code{watch-dir-enabled} is @code{#t}.
22780 Defaults to @samp{disabled}.
22784 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean trash-original-torrent-files?
22785 When @code{#t}, @file{.torrent} files will be deleted from the watch
22786 directory once their torrent has been added (see
22787 @code{watch-directory-enabled?}).
22789 Defaults to @samp{#f}.
22793 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean speed-limit-down-enabled?
22794 When @code{#t}, the daemon's download speed will be limited to the rate
22795 specified by @code{speed-limit-down}.
22797 Defaults to @samp{#f}.
22801 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer speed-limit-down
22802 The default global-maximum download speed, in kilobytes per second.
22804 Defaults to @samp{100}.
22808 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean speed-limit-up-enabled?
22809 When @code{#t}, the daemon's upload speed will be limited to the rate
22810 specified by @code{speed-limit-up}.
22812 Defaults to @samp{#f}.
22816 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer speed-limit-up
22817 The default global-maximum upload speed, in kilobytes per second.
22819 Defaults to @samp{100}.
22823 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean alt-speed-enabled?
22824 When @code{#t}, the alternate speed limits @code{alt-speed-down} and
22825 @code{alt-speed-up} are used (in place of @code{speed-limit-down} and
22826 @code{speed-limit-up}, if they are enabled) to constrain the daemon's
22827 bandwidth usage. This can be scheduled to occur automatically at
22828 certain times during the week; see @code{alt-speed-time-enabled?}.
22830 Defaults to @samp{#f}.
22834 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-down
22835 The alternate global-maximum download speed, in kilobytes per second.
22837 Defaults to @samp{50}.
22841 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-up
22842 The alternate global-maximum upload speed, in kilobytes per second.
22844 Defaults to @samp{50}.
22848 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean alt-speed-time-enabled?
22849 When @code{#t}, the alternate speed limits @code{alt-speed-down} and
22850 @code{alt-speed-up} will be enabled automatically during the periods
22851 specified by @code{alt-speed-time-day}, @code{alt-speed-time-begin} and
22852 @code{alt-time-speed-end}.
22854 Defaults to @samp{#f}.
22858 @deftypevr {@code{transmission-daemon-configuration} parameter} day-list alt-speed-time-day
22859 The days of the week on which the alternate-speed schedule should be
22860 used, specified either as a list of days (@code{sunday}, @code{monday},
22861 and so on) or using one of the symbols @code{weekdays}, @code{weekends}
22864 Defaults to @samp{all}.
22868 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-time-begin
22869 The time of day at which to enable the alternate speed limits, expressed
22870 as a number of minutes since midnight.
22872 Defaults to @samp{540}.
22876 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-time-end
22877 The time of day at which to disable the alternate speed limits,
22878 expressed as a number of minutes since midnight.
22880 Defaults to @samp{1020}.
22884 @deftypevr {@code{transmission-daemon-configuration} parameter} string bind-address-ipv4
22885 The IP address at which to listen for peer connections, or ``0.0.0.0''
22886 to listen at all available IP addresses.
22888 Defaults to @samp{"0.0.0.0"}.
22892 @deftypevr {@code{transmission-daemon-configuration} parameter} string bind-address-ipv6
22893 The IPv6 address at which to listen for peer connections, or ``::'' to
22894 listen at all available IPv6 addresses.
22896 Defaults to @samp{"::"}.
22900 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean peer-port-random-on-start?
22901 If @code{#t}, when the daemon starts it will select a port at random on
22902 which to listen for peer connections, from the range specified
22903 (inclusively) by @code{peer-port-random-low} and
22904 @code{peer-port-random-high}. Otherwise, it listens on the port
22905 specified by @code{peer-port}.
22907 Defaults to @samp{#f}.
22911 @deftypevr {@code{transmission-daemon-configuration} parameter} port-number peer-port-random-low
22912 The lowest selectable port number when @code{peer-port-random-on-start?}
22915 Defaults to @samp{49152}.
22919 @deftypevr {@code{transmission-daemon-configuration} parameter} port-number peer-port-random-high
22920 The highest selectable port number when @code{peer-port-random-on-start}
22923 Defaults to @samp{65535}.
22927 @deftypevr {@code{transmission-daemon-configuration} parameter} port-number peer-port
22928 The port on which to listen for peer connections when
22929 @code{peer-port-random-on-start?} is @code{#f}.
22931 Defaults to @samp{51413}.
22935 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean port-forwarding-enabled?
22936 If @code{#t}, the daemon will attempt to configure port-forwarding on an
22937 upstream gateway automatically using @acronym{UPnP} and
22940 Defaults to @samp{#t}.
22944 @deftypevr {@code{transmission-daemon-configuration} parameter} encryption-mode encryption
22945 The encryption preference for peer connections, one of
22946 @code{prefer-unencrypted-connections},
22947 @code{prefer-encrypted-connections} or
22948 @code{require-encrypted-connections}.
22950 Defaults to @samp{prefer-encrypted-connections}.
22954 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string peer-congestion-algorithm
22955 The TCP congestion-control algorithm to use for peer connections,
22956 specified using a string recognized by the operating system in calls to
22957 @code{setsockopt} (or set to @code{disabled}, in which case the
22958 operating-system default is used).
22960 Note that on GNU/Linux systems, the kernel must be configured to allow
22961 processes to use a congestion-control algorithm not in the default set;
22962 otherwise, it will deny these requests with ``Operation not permitted''.
22963 To see which algorithms are available on your system and which are
22964 currently permitted for use, look at the contents of the files
22965 @file{tcp_available_congestion_control} and
22966 @file{tcp_allowed_congestion_control} in the @file{/proc/sys/net/ipv4}
22969 As an example, to have Transmission Daemon use
22970 @uref{http://www-ece.rice.edu/networks/TCP-LP/,the TCP Low Priority
22971 congestion-control algorithm}, you'll need to modify your kernel
22972 configuration to build in support for the algorithm, then update your
22973 operating-system configuration to allow its use by adding a
22974 @code{sysctl-service-type} service (or updating the existing one's
22975 configuration) with lines like the following:
22978 (service sysctl-service-type
22979 (sysctl-configuration
22981 ("net.ipv4.tcp_allowed_congestion_control" .
22982 "reno cubic lp"))))
22985 The Transmission Daemon configuration can then be updated with
22988 (peer-congestion-algorithm "lp")
22991 and the system reconfigured to have the changes take effect.
22993 Defaults to @samp{disabled}.
22997 @deftypevr {@code{transmission-daemon-configuration} parameter} tcp-type-of-service peer-socket-tos
22998 The type of service to request in outgoing @acronym{TCP} packets, one of
22999 @code{default}, @code{low-cost}, @code{throughput}, @code{low-delay} and
23000 @code{reliability}.
23002 Defaults to @samp{default}.
23006 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer peer-limit-global
23007 The global limit on the number of connected peers.
23009 Defaults to @samp{200}.
23013 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer peer-limit-per-torrent
23014 The per-torrent limit on the number of connected peers.
23016 Defaults to @samp{50}.
23020 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer upload-slots-per-torrent
23021 The maximum number of peers to which the daemon will upload data
23022 simultaneously for each torrent.
23024 Defaults to @samp{14}.
23028 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer peer-id-ttl-hours
23029 The maximum lifespan, in hours, of the peer ID associated with each
23030 public torrent before it is regenerated.
23032 Defaults to @samp{6}.
23036 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean blocklist-enabled?
23037 When @code{#t}, the daemon will ignore peers mentioned in the blocklist
23038 it has most recently downloaded from @code{blocklist-url}.
23040 Defaults to @samp{#f}.
23044 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string blocklist-url
23045 The URL of a peer blocklist (in @acronym{P2P}-plaintext or eMule
23046 @file{.dat} format) to be periodically downloaded and applied when
23047 @code{blocklist-enabled?} is @code{#t}.
23049 Defaults to @samp{disabled}.
23053 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean download-queue-enabled?
23054 If @code{#t}, the daemon will be limited to downloading at most
23055 @code{download-queue-size} non-stalled torrents simultaneously.
23057 Defaults to @samp{#t}.
23061 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer download-queue-size
23062 The size of the daemon's download queue, which limits the number of
23063 non-stalled torrents it will download at any one time when
23064 @code{download-queue-enabled?} is @code{#t}.
23066 Defaults to @samp{5}.
23070 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean seed-queue-enabled?
23071 If @code{#t}, the daemon will be limited to seeding at most
23072 @code{seed-queue-size} non-stalled torrents simultaneously.
23074 Defaults to @samp{#f}.
23078 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer seed-queue-size
23079 The size of the daemon's seed queue, which limits the number of
23080 non-stalled torrents it will seed at any one time when
23081 @code{seed-queue-enabled?} is @code{#t}.
23083 Defaults to @samp{10}.
23087 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean queue-stalled-enabled?
23088 When @code{#t}, the daemon will consider torrents for which it has not
23089 shared data in the past @code{queue-stalled-minutes} minutes to be
23090 stalled and not count them against its @code{download-queue-size} and
23091 @code{seed-queue-size} limits.
23093 Defaults to @samp{#t}.
23097 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer queue-stalled-minutes
23098 The maximum period, in minutes, a torrent may be idle before it is
23099 considered to be stalled, when @code{queue-stalled-enabled?} is
23102 Defaults to @samp{30}.
23106 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean ratio-limit-enabled?
23107 When @code{#t}, a torrent being seeded will automatically be paused once
23108 it reaches the ratio specified by @code{ratio-limit}.
23110 Defaults to @samp{#f}.
23114 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-rational ratio-limit
23115 The ratio at which a torrent being seeded will be paused, when
23116 @code{ratio-limit-enabled?} is @code{#t}.
23118 Defaults to @samp{2.0}.
23122 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean idle-seeding-limit-enabled?
23123 When @code{#t}, a torrent being seeded will automatically be paused once
23124 it has been idle for @code{idle-seeding-limit} minutes.
23126 Defaults to @samp{#f}.
23130 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer idle-seeding-limit
23131 The maximum period, in minutes, a torrent being seeded may be idle
23132 before it is paused, when @code{idle-seeding-limit-enabled?} is
23135 Defaults to @samp{30}.
23139 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean dht-enabled?
23140 Enable @uref{http://bittorrent.org/beps/bep_0005.html,the distributed
23141 hash table (@acronym{DHT}) protocol}, which supports the use of
23142 trackerless torrents.
23144 Defaults to @samp{#t}.
23148 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean lpd-enabled?
23149 Enable @uref{https://en.wikipedia.org/wiki/Local_Peer_Discovery,local
23150 peer discovery} (@acronym{LPD}), which allows the discovery of peers on
23151 the local network and may reduce the amount of data sent over the public
23154 Defaults to @samp{#f}.
23158 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean pex-enabled?
23159 Enable @uref{https://en.wikipedia.org/wiki/Peer_exchange,peer exchange}
23160 (@acronym{PEX}), which reduces the daemon's reliance on external
23161 trackers and may improve its performance.
23163 Defaults to @samp{#t}.
23167 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean utp-enabled?
23168 Enable @uref{http://bittorrent.org/beps/bep_0029.html,the micro
23169 transport protocol} (@acronym{uTP}), which aims to reduce the impact of
23170 BitTorrent traffic on other users of the local network while maintaining
23171 full utilization of the available bandwidth.
23173 Defaults to @samp{#t}.
23177 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-enabled?
23178 If @code{#t}, enable the remote procedure call (@acronym{RPC})
23179 interface, which allows remote control of the daemon via its Web
23180 interface, the @command{transmission-remote} command-line client, and
23183 Defaults to @samp{#t}.
23187 @deftypevr {@code{transmission-daemon-configuration} parameter} string rpc-bind-address
23188 The IP address at which to listen for @acronym{RPC} connections, or
23189 ``0.0.0.0'' to listen at all available IP addresses.
23191 Defaults to @samp{"0.0.0.0"}.
23195 @deftypevr {@code{transmission-daemon-configuration} parameter} port-number rpc-port
23196 The port on which to listen for @acronym{RPC} connections.
23198 Defaults to @samp{9091}.
23202 @deftypevr {@code{transmission-daemon-configuration} parameter} string rpc-url
23203 The path prefix to use in the @acronym{RPC}-endpoint @acronym{URL}.
23205 Defaults to @samp{"/transmission/"}.
23209 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-authentication-required?
23210 When @code{#t}, clients must authenticate (see @code{rpc-username} and
23211 @code{rpc-password}) when using the @acronym{RPC} interface. Note this
23212 has the side effect of disabling host-name whitelisting (see
23213 @code{rpc-host-whitelist-enabled?}.
23215 Defaults to @samp{#f}.
23219 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string rpc-username
23220 The username required by clients to access the @acronym{RPC} interface
23221 when @code{rpc-authentication-required?} is @code{#t}.
23223 Defaults to @samp{disabled}.
23227 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-transmission-password-hash rpc-password
23228 The password required by clients to access the @acronym{RPC} interface
23229 when @code{rpc-authentication-required?} is @code{#t}. This must be
23230 specified using a password hash in the format recognized by Transmission
23231 clients, either copied from an existing @file{settings.json} file or
23232 generated using the @code{transmission-password-hash} procedure.
23234 Defaults to @samp{disabled}.
23238 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-whitelist-enabled?
23239 When @code{#t}, @acronym{RPC} requests will be accepted only when they
23240 originate from an address specified in @code{rpc-whitelist}.
23242 Defaults to @samp{#t}.
23246 @deftypevr {@code{transmission-daemon-configuration} parameter} string-list rpc-whitelist
23247 The list of IP and IPv6 addresses from which @acronym{RPC} requests will
23248 be accepted when @code{rpc-whitelist-enabled?} is @code{#t}. Wildcards
23249 may be specified using @samp{*}.
23251 Defaults to @samp{("127.0.0.1" "::1")}.
23255 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-host-whitelist-enabled?
23256 When @code{#t}, @acronym{RPC} requests will be accepted only when they
23257 are addressed to a host named in @code{rpc-host-whitelist}. Note that
23258 requests to ``localhost'' or ``localhost.'', or to a numeric address,
23259 are always accepted regardless of these settings.
23261 Note also this functionality is disabled when
23262 @code{rpc-authentication-required?} is @code{#t}.
23264 Defaults to @samp{#t}.
23268 @deftypevr {@code{transmission-daemon-configuration} parameter} string-list rpc-host-whitelist
23269 The list of host names recognized by the @acronym{RPC} server when
23270 @code{rpc-host-whitelist-enabled?} is @code{#t}.
23272 Defaults to @samp{()}.
23276 @deftypevr {@code{transmission-daemon-configuration} parameter} message-level message-level
23277 The minimum severity level of messages to be logged (to
23278 @file{/var/log/transmission.log}) by the daemon, one of @code{none} (no
23279 logging), @code{error}, @code{info} and @code{debug}.
23281 Defaults to @samp{info}.
23285 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean start-added-torrents?
23286 When @code{#t}, torrents are started as soon as they are added;
23287 otherwise, they are added in ``paused'' state.
23289 Defaults to @samp{#t}.
23293 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean script-torrent-done-enabled?
23294 When @code{#t}, the script specified by
23295 @code{script-torrent-done-filename} will be invoked each time a torrent
23298 Defaults to @samp{#f}.
23302 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-file-object script-torrent-done-filename
23303 A file name or file-like object specifying a script to run each time a
23304 torrent completes, when @code{script-torrent-done-enabled?} is
23307 Defaults to @samp{disabled}.
23311 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean scrape-paused-torrents-enabled?
23312 When @code{#t}, the daemon will scrape trackers for a torrent even when
23313 the torrent is paused.
23315 Defaults to @samp{#t}.
23319 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer cache-size-mb
23320 The amount of memory, in megabytes, to allocate for the daemon's
23321 in-memory cache. A larger value may increase performance by reducing
23322 the frequency of disk I/O.
23324 Defaults to @samp{4}.
23328 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean prefetch-enabled?
23329 When @code{#t}, the daemon will try to improve I/O performance by
23330 hinting to the operating system which data is likely to be read next
23331 from disk to satisfy requests from peers.
23333 Defaults to @samp{#t}.
23338 @c %end of fragment
23342 @node Monitoring Services
23343 @subsection Monitoring Services
23345 @subsubheading Tailon Service
23347 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
23348 viewing and searching log files.
23350 The following example will configure the service with default values.
23351 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
23354 (service tailon-service-type)
23357 The following example customises more of the Tailon configuration,
23358 adding @command{sed} to the list of allowed commands.
23361 (service tailon-service-type
23362 (tailon-configuration
23364 (tailon-configuration-file
23365 (allowed-commands '("tail" "grep" "awk" "sed"))))))
23369 @deftp {Data Type} tailon-configuration
23370 Data type representing the configuration of Tailon.
23371 This type has the following parameters:
23374 @item @code{config-file} (default: @code{(tailon-configuration-file)})
23375 The configuration file to use for Tailon. This can be set to a
23376 @dfn{tailon-configuration-file} record value, or any gexp
23377 (@pxref{G-Expressions}).
23379 For example, to instead use a local file, the @code{local-file} function
23383 (service tailon-service-type
23384 (tailon-configuration
23385 (config-file (local-file "./my-tailon.conf"))))
23388 @item @code{package} (default: @code{tailon})
23389 The tailon package to use.
23394 @deftp {Data Type} tailon-configuration-file
23395 Data type representing the configuration options for Tailon.
23396 This type has the following parameters:
23399 @item @code{files} (default: @code{(list "/var/log")})
23400 List of files to display. The list can include strings for a single file
23401 or directory, or a list, where the first item is the name of a
23402 subsection, and the remaining items are the files or directories in that
23405 @item @code{bind} (default: @code{"localhost:8080"})
23406 Address and port to which Tailon should bind on.
23408 @item @code{relative-root} (default: @code{#f})
23409 URL path to use for Tailon, set to @code{#f} to not use a path.
23411 @item @code{allow-transfers?} (default: @code{#t})
23412 Allow downloading the log files in the web interface.
23414 @item @code{follow-names?} (default: @code{#t})
23415 Allow tailing of not-yet existent files.
23417 @item @code{tail-lines} (default: @code{200})
23418 Number of lines to read initially from each file.
23420 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
23421 Commands to allow running. By default, @code{sed} is disabled.
23423 @item @code{debug?} (default: @code{#f})
23424 Set @code{debug?} to @code{#t} to show debug messages.
23426 @item @code{wrap-lines} (default: @code{#t})
23427 Initial line wrapping state in the web interface. Set to @code{#t} to
23428 initially wrap lines (the default), or to @code{#f} to initially not
23431 @item @code{http-auth} (default: @code{#f})
23432 HTTP authentication type to use. Set to @code{#f} to disable
23433 authentication (the default). Supported values are @code{"digest"} or
23436 @item @code{users} (default: @code{#f})
23437 If HTTP authentication is enabled (see @code{http-auth}), access will be
23438 restricted to the credentials provided here. To configure users, use a
23439 list of pairs, where the first element of the pair is the username, and
23440 the 2nd element of the pair is the password.
23443 (tailon-configuration-file
23444 (http-auth "basic")
23445 (users '(("user1" . "password1")
23446 ("user2" . "password2"))))
23453 @subsubheading Darkstat Service
23455 Darkstat is a packet sniffer that captures network traffic, calculates
23456 statistics about usage, and serves reports over HTTP.
23458 @defvar {Scheme Variable} darkstat-service-type
23459 This is the service type for the
23460 @uref{https://unix4lyfe.org/darkstat/, darkstat}
23461 service, its value must be a @code{darkstat-configuration} record as in
23465 (service darkstat-service-type
23466 (darkstat-configuration
23467 (interface "eno1")))
23471 @deftp {Data Type} darkstat-configuration
23472 Data type representing the configuration of @command{darkstat}.
23475 @item @code{package} (default: @code{darkstat})
23476 The darkstat package to use.
23478 @item @code{interface}
23479 Capture traffic on the specified network interface.
23481 @item @code{port} (default: @code{"667"})
23482 Bind the web interface to the specified port.
23484 @item @code{bind-address} (default: @code{"127.0.0.1"})
23485 Bind the web interface to the specified address.
23487 @item @code{base} (default: @code{"/"})
23488 Specify the path of the base URL@. This can be useful if
23489 @command{darkstat} is accessed via a reverse proxy.
23494 @subsubheading Prometheus Node Exporter Service
23496 @cindex prometheus-node-exporter
23497 The Prometheus ``node exporter'' makes hardware and operating system statistics
23498 provided by the Linux kernel available for the Prometheus monitoring system.
23499 This service should be deployed on all physical nodes and virtual machines,
23500 where monitoring these statistics is desirable.
23502 @defvar {Scheme variable} prometheus-node-exporter-service-type
23503 This is the service type for the
23504 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
23505 service, its value must be a @code{prometheus-node-exporter-configuration}.
23508 (service prometheus-node-exporter-service-type)
23512 @deftp {Data Type} prometheus-node-exporter-configuration
23513 Data type representing the configuration of @command{node_exporter}.
23516 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
23517 The prometheus-node-exporter package to use.
23519 @item @code{web-listen-address} (default: @code{":9100"})
23520 Bind the web interface to the specified address.
23522 @item @code{textfile-directory} (default: @code{"/var/lib/prometheus/node-exporter"})
23523 This directory can be used to export metrics specific to this machine.
23524 Files containing metrics in the text format, with the filename ending in
23525 @code{.prom} should be placed in this directory.
23527 @item @code{extra-options} (default: @code{'()})
23528 Extra options to pass to the Prometheus node exporter.
23533 @subsubheading Zabbix server
23534 @cindex zabbix zabbix-server
23535 Zabbix provides monitoring metrics, among others network utilization, CPU load
23536 and disk space consumption:
23539 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
23540 @item Auto-discovery of servers and network devices and interfaces.
23541 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
23542 @item Distributed monitoring with centralized web administration.
23543 @item Native high performance agents.
23544 @item SLA, and ITIL KPI metrics on reporting.
23545 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
23546 @item Remote command execution through Zabbix proxies.
23549 @c %start of fragment
23551 Available @code{zabbix-server-configuration} fields are:
23553 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
23554 The zabbix-server package.
23558 @deftypevr {@code{zabbix-server-configuration} parameter} string user
23559 User who will run the Zabbix server.
23561 Defaults to @samp{"zabbix"}.
23565 @deftypevr {@code{zabbix-server-configuration} parameter} group group
23566 Group who will run the Zabbix server.
23568 Defaults to @samp{"zabbix"}.
23572 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
23573 Database host name.
23575 Defaults to @samp{"127.0.0.1"}.
23579 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
23582 Defaults to @samp{"zabbix"}.
23586 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
23589 Defaults to @samp{"zabbix"}.
23593 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
23594 Database password. Please, use @code{include-files} with
23595 @code{DBPassword=SECRET} inside a specified file instead.
23597 Defaults to @samp{""}.
23601 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
23604 Defaults to @samp{5432}.
23608 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
23609 Specifies where log messages are written to:
23613 @code{system} - syslog.
23616 @code{file} - file specified with @code{log-file} parameter.
23619 @code{console} - standard output.
23623 Defaults to @samp{""}.
23627 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
23628 Log file name for @code{log-type} @code{file} parameter.
23630 Defaults to @samp{"/var/log/zabbix/server.log"}.
23634 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
23637 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
23641 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
23642 The location of certificate authority (CA) files for SSL server
23643 certificate verification.
23645 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
23649 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
23650 Location of SSL client certificates.
23652 Defaults to @samp{"/etc/ssl/certs"}.
23656 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
23657 Extra options will be appended to Zabbix server configuration file.
23659 Defaults to @samp{""}.
23663 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
23664 You may include individual files or all files in a directory in the
23665 configuration file.
23667 Defaults to @samp{()}.
23671 @c %end of fragment
23673 @subsubheading Zabbix agent
23674 @cindex zabbix zabbix-agent
23676 Zabbix agent gathers information for Zabbix server.
23678 @c %start of fragment
23680 Available @code{zabbix-agent-configuration} fields are:
23682 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
23683 The zabbix-agent package.
23687 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
23688 User who will run the Zabbix agent.
23690 Defaults to @samp{"zabbix"}.
23694 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
23695 Group who will run the Zabbix agent.
23697 Defaults to @samp{"zabbix"}.
23701 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
23702 Unique, case sensitive hostname which is required for active checks and
23703 must match hostname as configured on the server.
23705 Defaults to @samp{""}.
23709 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
23710 Specifies where log messages are written to:
23714 @code{system} - syslog.
23717 @code{file} - file specified with @code{log-file} parameter.
23720 @code{console} - standard output.
23724 Defaults to @samp{""}.
23728 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
23729 Log file name for @code{log-type} @code{file} parameter.
23731 Defaults to @samp{"/var/log/zabbix/agent.log"}.
23735 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
23738 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
23742 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
23743 List of IP addresses, optionally in CIDR notation, or hostnames of
23744 Zabbix servers and Zabbix proxies. Incoming connections will be
23745 accepted only from the hosts listed here.
23747 Defaults to @samp{("127.0.0.1")}.
23751 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
23752 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
23753 proxies for active checks. If port is not specified, default port is
23754 used. If this parameter is not specified, active checks are disabled.
23756 Defaults to @samp{("127.0.0.1")}.
23760 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
23761 Extra options will be appended to Zabbix server configuration file.
23763 Defaults to @samp{""}.
23767 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
23768 You may include individual files or all files in a directory in the
23769 configuration file.
23771 Defaults to @samp{()}.
23775 @c %end of fragment
23777 @subsubheading Zabbix front-end
23778 @cindex zabbix zabbix-front-end
23780 This service provides a WEB interface to Zabbix server.
23782 @c %start of fragment
23784 Available @code{zabbix-front-end-configuration} fields are:
23786 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
23787 NGINX configuration.
23791 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
23792 Database host name.
23794 Defaults to @samp{"localhost"}.
23798 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
23801 Defaults to @samp{5432}.
23805 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
23808 Defaults to @samp{"zabbix"}.
23812 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
23815 Defaults to @samp{"zabbix"}.
23819 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
23820 Database password. Please, use @code{db-secret-file} instead.
23822 Defaults to @samp{""}.
23826 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
23827 Secret file containing the credentials for the Zabbix front-end. The value
23828 must be a local file name, not a G-expression. You are expected to create
23829 this file manually. Its contents will be copied into @file{zabbix.conf.php}
23830 as the value of @code{$DB['PASSWORD']}.
23832 Defaults to @samp{""}.
23836 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
23837 Zabbix server hostname.
23839 Defaults to @samp{"localhost"}.
23843 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
23844 Zabbix server port.
23846 Defaults to @samp{10051}.
23851 @c %end of fragment
23853 @node Kerberos Services
23854 @subsection Kerberos Services
23857 The @code{(gnu services kerberos)} module provides services relating to
23858 the authentication protocol @dfn{Kerberos}.
23860 @subsubheading Krb5 Service
23862 Programs using a Kerberos client library normally
23863 expect a configuration file in @file{/etc/krb5.conf}.
23864 This service generates such a file from a definition provided in the
23865 operating system declaration.
23866 It does not cause any daemon to be started.
23868 No ``keytab'' files are provided by this service---you must explicitly create them.
23869 This service is known to work with the MIT client library, @code{mit-krb5}.
23870 Other implementations have not been tested.
23872 @defvr {Scheme Variable} krb5-service-type
23873 A service type for Kerberos 5 clients.
23877 Here is an example of its use:
23879 (service krb5-service-type
23880 (krb5-configuration
23881 (default-realm "EXAMPLE.COM")
23882 (allow-weak-crypto? #t)
23885 (name "EXAMPLE.COM")
23886 (admin-server "groucho.example.com")
23887 (kdc "karl.example.com"))
23890 (admin-server "kerb-admin.argrx.edu")
23891 (kdc "keys.argrx.edu"))))))
23895 This example provides a Kerberos@tie{}5 client configuration which:
23897 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
23898 of which have distinct administration servers and key distribution centers;
23899 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
23900 specified by clients;
23901 @item Accepts services which only support encryption types known to be weak.
23904 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
23905 Only the most commonly used ones are described here.
23906 For a full list, and more detailed explanation of each, see the MIT
23907 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
23911 @deftp {Data Type} krb5-realm
23912 @cindex realm, kerberos
23915 This field is a string identifying the name of the realm.
23916 A common convention is to use the fully qualified DNS name of your organization,
23917 converted to upper case.
23919 @item @code{admin-server}
23920 This field is a string identifying the host where the administration server is
23924 This field is a string identifying the key distribution center
23929 @deftp {Data Type} krb5-configuration
23932 @item @code{allow-weak-crypto?} (default: @code{#f})
23933 If this flag is @code{#t} then services which only offer encryption algorithms
23934 known to be weak will be accepted.
23936 @item @code{default-realm} (default: @code{#f})
23937 This field should be a string identifying the default Kerberos
23938 realm for the client.
23939 You should set this field to the name of your Kerberos realm.
23940 If this value is @code{#f}
23941 then a realm must be specified with every Kerberos principal when invoking programs
23942 such as @command{kinit}.
23944 @item @code{realms}
23945 This should be a non-empty list of @code{krb5-realm} objects, which clients may
23947 Normally, one of them will have a @code{name} field matching the @code{default-realm}
23953 @subsubheading PAM krb5 Service
23956 The @code{pam-krb5} service allows for login authentication and password
23957 management via Kerberos.
23958 You will need this service if you want PAM enabled applications to authenticate
23959 users using Kerberos.
23961 @defvr {Scheme Variable} pam-krb5-service-type
23962 A service type for the Kerberos 5 PAM module.
23965 @deftp {Data Type} pam-krb5-configuration
23966 Data type representing the configuration of the Kerberos 5 PAM module.
23967 This type has the following parameters:
23969 @item @code{pam-krb5} (default: @code{pam-krb5})
23970 The pam-krb5 package to use.
23972 @item @code{minimum-uid} (default: @code{1000})
23973 The smallest user ID for which Kerberos authentications should be attempted.
23974 Local accounts with lower values will silently fail to authenticate.
23979 @node LDAP Services
23980 @subsection LDAP Services
23982 @cindex nslcd, LDAP service
23984 The @code{(gnu services authentication)} module provides the
23985 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
23986 server. In addition to configuring the service itself, you may want to add
23987 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
23988 Switch} for detailed information.
23990 Here is a simple operating system declaration with a default configuration of
23991 the @code{nslcd-service-type} and a Name Service Switch configuration that
23992 consults the @code{ldap} name service last:
23995 (use-service-modules authentication)
23996 (use-modules (gnu system nss))
24002 (service nslcd-service-type)
24003 (service dhcp-client-service-type)
24005 (name-service-switch
24006 (let ((services (list (name-service (name "db"))
24007 (name-service (name "files"))
24008 (name-service (name "ldap")))))
24009 (name-service-switch
24010 (inherit %mdns-host-lookup-nss)
24011 (password services)
24014 (netgroup services)
24015 (gshadow services)))))
24018 @c %start of generated documentation for nslcd-configuration
24020 Available @code{nslcd-configuration} fields are:
24022 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
24023 The @code{nss-pam-ldapd} package to use.
24027 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
24028 The number of threads to start that can handle requests and perform LDAP
24029 queries. Each thread opens a separate connection to the LDAP server.
24030 The default is to start 5 threads.
24032 Defaults to @samp{disabled}.
24036 @deftypevr {@code{nslcd-configuration} parameter} string uid
24037 This specifies the user id with which the daemon should be run.
24039 Defaults to @samp{"nslcd"}.
24043 @deftypevr {@code{nslcd-configuration} parameter} string gid
24044 This specifies the group id with which the daemon should be run.
24046 Defaults to @samp{"nslcd"}.
24050 @deftypevr {@code{nslcd-configuration} parameter} log-option log
24051 This option controls the way logging is done via a list containing
24052 SCHEME and LEVEL@. The SCHEME argument may either be the symbols
24053 @samp{none} or @samp{syslog}, or an absolute file name. The LEVEL
24054 argument is optional and specifies the log level. The log level may be
24055 one of the following symbols: @samp{crit}, @samp{error}, @samp{warning},
24056 @samp{notice}, @samp{info} or @samp{debug}. All messages with the
24057 specified log level or higher are logged.
24059 Defaults to @samp{("/var/log/nslcd" info)}.
24063 @deftypevr {@code{nslcd-configuration} parameter} list uri
24064 The list of LDAP server URIs. Normally, only the first server will be
24065 used with the following servers as fall-back.
24067 Defaults to @samp{("ldap://localhost:389/")}.
24071 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
24072 The version of the LDAP protocol to use. The default is to use the
24073 maximum version supported by the LDAP library.
24075 Defaults to @samp{disabled}.
24079 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
24080 Specifies the distinguished name with which to bind to the directory
24081 server for lookups. The default is to bind anonymously.
24083 Defaults to @samp{disabled}.
24087 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
24088 Specifies the credentials with which to bind. This option is only
24089 applicable when used with binddn.
24091 Defaults to @samp{disabled}.
24095 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
24096 Specifies the distinguished name to use when the root user tries to
24097 modify a user's password using the PAM module.
24099 Defaults to @samp{disabled}.
24103 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
24104 Specifies the credentials with which to bind if the root user tries to
24105 change a user's password. This option is only applicable when used with
24108 Defaults to @samp{disabled}.
24112 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
24113 Specifies the SASL mechanism to be used when performing SASL
24116 Defaults to @samp{disabled}.
24120 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
24121 Specifies the SASL realm to be used when performing SASL authentication.
24123 Defaults to @samp{disabled}.
24127 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
24128 Specifies the authentication identity to be used when performing SASL
24131 Defaults to @samp{disabled}.
24135 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
24136 Specifies the authorization identity to be used when performing SASL
24139 Defaults to @samp{disabled}.
24143 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
24144 Determines whether the LDAP server host name should be canonicalised. If
24145 this is enabled the LDAP library will do a reverse host name lookup. By
24146 default, it is left up to the LDAP library whether this check is
24149 Defaults to @samp{disabled}.
24153 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
24154 Set the name for the GSS-API Kerberos credentials cache.
24156 Defaults to @samp{disabled}.
24160 @deftypevr {@code{nslcd-configuration} parameter} string base
24161 The directory search base.
24163 Defaults to @samp{"dc=example,dc=com"}.
24167 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
24168 Specifies the search scope (subtree, onelevel, base or children). The
24169 default scope is subtree; base scope is almost never useful for name
24170 service lookups; children scope is not supported on all servers.
24172 Defaults to @samp{(subtree)}.
24176 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
24177 Specifies the policy for dereferencing aliases. The default policy is
24178 to never dereference aliases.
24180 Defaults to @samp{disabled}.
24184 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
24185 Specifies whether automatic referral chasing should be enabled. The
24186 default behaviour is to chase referrals.
24188 Defaults to @samp{disabled}.
24192 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
24193 This option allows for custom attributes to be looked up instead of the
24194 default RFC 2307 attributes. It is a list of maps, each consisting of
24195 the name of a map, the RFC 2307 attribute to match and the query
24196 expression for the attribute as it is available in the directory.
24198 Defaults to @samp{()}.
24202 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
24203 A list of filters consisting of the name of a map to which the filter
24204 applies and an LDAP search filter expression.
24206 Defaults to @samp{()}.
24210 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
24211 Specifies the time limit in seconds to use when connecting to the
24212 directory server. The default value is 10 seconds.
24214 Defaults to @samp{disabled}.
24218 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
24219 Specifies the time limit (in seconds) to wait for a response from the
24220 LDAP server. A value of zero, which is the default, is to wait
24221 indefinitely for searches to be completed.
24223 Defaults to @samp{disabled}.
24227 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
24228 Specifies the period if inactivity (in seconds) after which the con‐
24229 nection to the LDAP server will be closed. The default is not to time
24232 Defaults to @samp{disabled}.
24236 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
24237 Specifies the number of seconds to sleep when connecting to all LDAP
24238 servers fails. By default one second is waited between the first
24239 failure and the first retry.
24241 Defaults to @samp{disabled}.
24245 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
24246 Specifies the time after which the LDAP server is considered to be
24247 permanently unavailable. Once this time is reached retries will be done
24248 only once per this time period. The default value is 10 seconds.
24250 Defaults to @samp{disabled}.
24254 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
24255 Specifies whether to use SSL/TLS or not (the default is not to). If
24256 'start-tls is specified then StartTLS is used rather than raw LDAP over
24259 Defaults to @samp{disabled}.
24263 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
24264 Specifies what checks to perform on a server-supplied certificate. The
24265 meaning of the values is described in the ldap.conf(5) manual page.
24267 Defaults to @samp{disabled}.
24271 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
24272 Specifies the directory containing X.509 certificates for peer authen‐
24273 tication. This parameter is ignored when using GnuTLS.
24275 Defaults to @samp{disabled}.
24279 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
24280 Specifies the path to the X.509 certificate for peer authentication.
24282 Defaults to @samp{disabled}.
24286 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
24287 Specifies the path to an entropy source. This parameter is ignored when
24290 Defaults to @samp{disabled}.
24294 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
24295 Specifies the ciphers to use for TLS as a string.
24297 Defaults to @samp{disabled}.
24301 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
24302 Specifies the path to the file containing the local certificate for
24303 client TLS authentication.
24305 Defaults to @samp{disabled}.
24309 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
24310 Specifies the path to the file containing the private key for client TLS
24313 Defaults to @samp{disabled}.
24317 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
24318 Set this to a number greater than 0 to request paged results from the
24319 LDAP server in accordance with RFC2696. The default (0) is to not
24320 request paged results.
24322 Defaults to @samp{disabled}.
24326 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
24327 This option prevents group membership lookups through LDAP for the
24328 specified users. Alternatively, the value 'all-local may be used. With
24329 that value nslcd builds a full list of non-LDAP users on startup.
24331 Defaults to @samp{disabled}.
24335 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
24336 This option ensures that LDAP users with a numeric user id lower than
24337 the specified value are ignored.
24339 Defaults to @samp{disabled}.
24343 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
24344 This option specifies an offset that is added to all LDAP numeric user
24345 ids. This can be used to avoid user id collisions with local users.
24347 Defaults to @samp{disabled}.
24351 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
24352 This option specifies an offset that is added to all LDAP numeric group
24353 ids. This can be used to avoid user id collisions with local groups.
24355 Defaults to @samp{disabled}.
24359 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
24360 If this option is set, the member attribute of a group may point to
24361 another group. Members of nested groups are also returned in the higher
24362 level group and parent groups are returned when finding groups for a
24363 specific user. The default is not to perform extra searches for nested
24366 Defaults to @samp{disabled}.
24370 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
24371 If this option is set, the group member list is not retrieved when
24372 looking up groups. Lookups for finding which groups a user belongs to
24373 will remain functional so the user will likely still get the correct
24374 groups assigned on login.
24376 Defaults to @samp{disabled}.
24380 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
24381 If this option is set, functions which cause all user/group entries to
24382 be loaded from the directory will not succeed in doing so. This can
24383 dramatically reduce LDAP server load in situations where there are a
24384 great number of users and/or groups. This option is not recommended for
24385 most configurations.
24387 Defaults to @samp{disabled}.
24391 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
24392 This option can be used to specify how user and group names are verified
24393 within the system. This pattern is used to check all user and group
24394 names that are requested and returned from LDAP.
24396 Defaults to @samp{disabled}.
24400 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
24401 This specifies whether or not to perform searches using case-insensitive
24402 matching. Enabling this could open up the system to authorization
24403 bypass vulnerabilities and introduce nscd cache poisoning
24404 vulnerabilities which allow denial of service.
24406 Defaults to @samp{disabled}.
24410 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
24411 This option specifies whether password policy controls are requested and
24412 handled from the LDAP server when performing user authentication.
24414 Defaults to @samp{disabled}.
24418 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
24419 By default nslcd performs an LDAP search with the user's credentials
24420 after BIND (authentication) to ensure that the BIND operation was
24421 successful. The default search is a simple check to see if the user's
24422 DN exists. A search filter can be specified that will be used instead.
24423 It should return at least one entry.
24425 Defaults to @samp{disabled}.
24429 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
24430 This option allows flexible fine tuning of the authorisation check that
24431 should be performed. The search filter specified is executed and if any
24432 entries match, access is granted, otherwise access is denied.
24434 Defaults to @samp{disabled}.
24438 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
24439 If this option is set password modification using pam_ldap will be
24440 denied and the specified message will be presented to the user instead.
24441 The message can be used to direct the user to an alternative means of
24442 changing their password.
24444 Defaults to @samp{disabled}.
24448 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
24449 List of pam service names for which LDAP authentication should suffice.
24451 Defaults to @samp{()}.
24455 @c %end of generated documentation for nslcd-configuration
24459 @subsection Web Services
24464 The @code{(gnu services web)} module provides the Apache HTTP Server,
24465 the nginx web server, and also a fastcgi wrapper daemon.
24467 @subsubheading Apache HTTP Server
24469 @deffn {Scheme Variable} httpd-service-type
24470 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
24471 (@dfn{httpd}). The value for this service type is a
24472 @code{httpd-configuration} record.
24474 A simple example configuration is given below.
24477 (service httpd-service-type
24478 (httpd-configuration
24481 (server-name "www.example.com")
24482 (document-root "/srv/http/www.example.com")))))
24485 Other services can also extend the @code{httpd-service-type} to add to
24489 (simple-service 'www.example.com-server httpd-service-type
24493 (list (string-join '("ServerName www.example.com"
24494 "DocumentRoot /srv/http/www.example.com")
24499 The details for the @code{httpd-configuration}, @code{httpd-module},
24500 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
24503 @deffn {Data Type} httpd-configuration
24504 This data type represents the configuration for the httpd service.
24507 @item @code{package} (default: @code{httpd})
24508 The httpd package to use.
24510 @item @code{pid-file} (default: @code{"/var/run/httpd"})
24511 The pid file used by the shepherd-service.
24513 @item @code{config} (default: @code{(httpd-config-file)})
24514 The configuration file to use with the httpd service. The default value
24515 is a @code{httpd-config-file} record, but this can also be a different
24516 G-expression that generates a file, for example a @code{plain-file}. A
24517 file outside of the store can also be specified through a string.
24522 @deffn {Data Type} httpd-module
24523 This data type represents a module for the httpd service.
24527 The name of the module.
24530 The file for the module. This can be relative to the httpd package being
24531 used, the absolute location of a file, or a G-expression for a file
24532 within the store, for example @code{(file-append mod-wsgi
24533 "/modules/mod_wsgi.so")}.
24538 @defvr {Scheme Variable} %default-httpd-modules
24539 A default list of @code{httpd-module} objects.
24542 @deffn {Data Type} httpd-config-file
24543 This data type represents a configuration file for the httpd service.
24546 @item @code{modules} (default: @code{%default-httpd-modules})
24547 The modules to load. Additional modules can be added here, or loaded by
24548 additional configuration.
24550 For example, in order to handle requests for PHP files, you can use Apache’s
24551 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
24554 (service httpd-service-type
24555 (httpd-configuration
24560 (name "proxy_module")
24561 (file "modules/mod_proxy.so"))
24563 (name "proxy_fcgi_module")
24564 (file "modules/mod_proxy_fcgi.so"))
24565 %default-httpd-modules))
24566 (extra-config (list "\
24567 <FilesMatch \\.php$>
24568 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
24569 </FilesMatch>"))))))
24570 (service php-fpm-service-type
24571 (php-fpm-configuration
24572 (socket "/var/run/php-fpm.sock")
24573 (socket-group "httpd")))
24576 @item @code{server-root} (default: @code{httpd})
24577 The @code{ServerRoot} in the configuration file, defaults to the httpd
24578 package. Directives including @code{Include} and @code{LoadModule} are
24579 taken as relative to the server root.
24581 @item @code{server-name} (default: @code{#f})
24582 The @code{ServerName} in the configuration file, used to specify the
24583 request scheme, hostname and port that the server uses to identify
24586 This doesn't need to be set in the server config, and can be specified
24587 in virtual hosts. The default is @code{#f} to not specify a
24590 @item @code{document-root} (default: @code{"/srv/http"})
24591 The @code{DocumentRoot} from which files will be served.
24593 @item @code{listen} (default: @code{'("80")})
24594 The list of values for the @code{Listen} directives in the config
24595 file. The value should be a list of strings, when each string can
24596 specify the port number to listen on, and optionally the IP address and
24599 @item @code{pid-file} (default: @code{"/var/run/httpd"})
24600 The @code{PidFile} to use. This should match the @code{pid-file} set in
24601 the @code{httpd-configuration} so that the Shepherd service is
24602 configured correctly.
24604 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
24605 The @code{ErrorLog} to which the server will log errors.
24607 @item @code{user} (default: @code{"httpd"})
24608 The @code{User} which the server will answer requests as.
24610 @item @code{group} (default: @code{"httpd"})
24611 The @code{Group} which the server will answer requests as.
24613 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
24614 A flat list of strings and G-expressions which will be added to the end
24615 of the configuration file.
24617 Any values which the service is extended with will be appended to this
24623 @deffn {Data Type} httpd-virtualhost
24624 This data type represents a virtualhost configuration block for the httpd service.
24626 These should be added to the extra-config for the httpd-service.
24629 (simple-service 'www.example.com-server httpd-service-type
24633 (list (string-join '("ServerName www.example.com"
24634 "DocumentRoot /srv/http/www.example.com")
24639 @item @code{addresses-and-ports}
24640 The addresses and ports for the @code{VirtualHost} directive.
24642 @item @code{contents}
24643 The contents of the @code{VirtualHost} directive, this should be a list
24644 of strings and G-expressions.
24649 @subsubheading NGINX
24651 @deffn {Scheme Variable} nginx-service-type
24652 Service type for the @uref{https://nginx.org/,NGinx} web server. The
24653 value for this service type is a @code{<nginx-configuration>} record.
24655 A simple example configuration is given below.
24658 (service nginx-service-type
24659 (nginx-configuration
24661 (list (nginx-server-configuration
24662 (server-name '("www.example.com"))
24663 (root "/srv/http/www.example.com"))))))
24666 In addition to adding server blocks to the service configuration
24667 directly, this service can be extended by other services to add server
24668 blocks, as in this example:
24671 (simple-service 'my-extra-server nginx-service-type
24672 (list (nginx-server-configuration
24673 (root "/srv/http/extra-website")
24674 (try-files (list "$uri" "$uri/index.html")))))
24678 At startup, @command{nginx} has not yet read its configuration file, so
24679 it uses a default file to log error messages. If it fails to load its
24680 configuration file, that is where error messages are logged. After the
24681 configuration file is loaded, the default error log file changes as per
24682 configuration. In our case, startup error messages can be found in
24683 @file{/var/run/nginx/logs/error.log}, and after configuration in
24684 @file{/var/log/nginx/error.log}. The second location can be changed
24685 with the @var{log-directory} configuration option.
24687 @deffn {Data Type} nginx-configuration
24688 This data type represents the configuration for NGinx. Some
24689 configuration can be done through this and the other provided record
24690 types, or alternatively, a config file can be provided.
24693 @item @code{nginx} (default: @code{nginx})
24694 The nginx package to use.
24696 @item @code{log-directory} (default: @code{"/var/log/nginx"})
24697 The directory to which NGinx will write log files.
24699 @item @code{run-directory} (default: @code{"/var/run/nginx"})
24700 The directory in which NGinx will create a pid file, and write temporary
24703 @item @code{server-blocks} (default: @code{'()})
24704 A list of @dfn{server blocks} to create in the generated configuration
24705 file, the elements should be of type
24706 @code{<nginx-server-configuration>}.
24708 The following example would setup NGinx to serve @code{www.example.com}
24709 from the @code{/srv/http/www.example.com} directory, without using
24712 (service nginx-service-type
24713 (nginx-configuration
24715 (list (nginx-server-configuration
24716 (server-name '("www.example.com"))
24717 (root "/srv/http/www.example.com"))))))
24720 @item @code{upstream-blocks} (default: @code{'()})
24721 A list of @dfn{upstream blocks} to create in the generated configuration
24722 file, the elements should be of type
24723 @code{<nginx-upstream-configuration>}.
24725 Configuring upstreams through the @code{upstream-blocks} can be useful
24726 when combined with @code{locations} in the
24727 @code{<nginx-server-configuration>} records. The following example
24728 creates a server configuration with one location configuration, that
24729 will proxy requests to a upstream configuration, which will handle
24730 requests with two servers.
24735 (nginx-configuration
24737 (list (nginx-server-configuration
24738 (server-name '("www.example.com"))
24739 (root "/srv/http/www.example.com")
24742 (nginx-location-configuration
24744 (body '("proxy_pass http://server-proxy;"))))))))
24746 (list (nginx-upstream-configuration
24747 (name "server-proxy")
24748 (servers (list "server1.example.com"
24749 "server2.example.com")))))))
24752 @item @code{file} (default: @code{#f})
24753 If a configuration @var{file} is provided, this will be used, rather than
24754 generating a configuration file from the provided @code{log-directory},
24755 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
24756 proper operation, these arguments should match what is in @var{file} to ensure
24757 that the directories are created when the service is activated.
24759 This can be useful if you have an existing configuration file, or it's
24760 not possible to do what is required through the other parts of the
24761 nginx-configuration record.
24763 @item @code{server-names-hash-bucket-size} (default: @code{#f})
24764 Bucket size for the server names hash tables, defaults to @code{#f} to
24765 use the size of the processors cache line.
24767 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
24768 Maximum bucket size for the server names hash tables.
24770 @item @code{modules} (default: @code{'()})
24771 List of nginx dynamic modules to load. This should be a list of file
24772 names of loadable modules, as in this example:
24777 (file-append nginx-accept-language-module "\
24778 /etc/nginx/modules/ngx_http_accept_language_module.so")
24779 (file-append nginx-lua-module "\
24780 /etc/nginx/modules/ngx_http_lua_module.so")))
24783 @item @code{lua-package-path} (default: @code{'()})
24784 List of nginx lua packages to load. This should be a list of package
24785 names of loadable lua modules, as in this example:
24788 (lua-package-path (list lua-resty-core
24795 @item @code{lua-package-cpath} (default: @code{'()})
24796 List of nginx lua C packages to load. This should be a list of package
24797 names of loadable lua C modules, as in this example:
24800 (lua-package-cpath (list lua-resty-signal))
24803 @item @code{global-directives} (default: @code{'((events . ()))})
24804 Association list of global directives for the top level of the nginx
24805 configuration. Values may themselves be association lists.
24809 `((worker_processes . 16)
24811 (events . ((worker_connections . 1024)))))
24814 @item @code{extra-content} (default: @code{""})
24815 Extra content for the @code{http} block. Should be string or a string
24816 valued G-expression.
24821 @deftp {Data Type} nginx-server-configuration
24822 Data type representing the configuration of an nginx server block.
24823 This type has the following parameters:
24826 @item @code{listen} (default: @code{'("80" "443 ssl")})
24827 Each @code{listen} directive sets the address and port for IP, or the
24828 path for a UNIX-domain socket on which the server will accept requests.
24829 Both address and port, or only address or only port can be specified.
24830 An address may also be a hostname, for example:
24833 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
24836 @item @code{server-name} (default: @code{(list 'default)})
24837 A list of server names this server represents. @code{'default} represents the
24838 default server for connections matching no other server.
24840 @item @code{root} (default: @code{"/srv/http"})
24841 Root of the website nginx will serve.
24843 @item @code{locations} (default: @code{'()})
24844 A list of @dfn{nginx-location-configuration} or
24845 @dfn{nginx-named-location-configuration} records to use within this
24848 @item @code{index} (default: @code{(list "index.html")})
24849 Index files to look for when clients ask for a directory. If it cannot be found,
24850 Nginx will send the list of files in the directory.
24852 @item @code{try-files} (default: @code{'()})
24853 A list of files whose existence is checked in the specified order.
24854 @code{nginx} will use the first file it finds to process the request.
24856 @item @code{ssl-certificate} (default: @code{#f})
24857 Where to find the certificate for secure connections. Set it to @code{#f} if
24858 you don't have a certificate or you don't want to use HTTPS.
24860 @item @code{ssl-certificate-key} (default: @code{#f})
24861 Where to find the private key for secure connections. Set it to @code{#f} if
24862 you don't have a key or you don't want to use HTTPS.
24864 @item @code{server-tokens?} (default: @code{#f})
24865 Whether the server should add its configuration to response.
24867 @item @code{raw-content} (default: @code{'()})
24868 A list of raw lines added to the server block.
24873 @deftp {Data Type} nginx-upstream-configuration
24874 Data type representing the configuration of an nginx @code{upstream}
24875 block. This type has the following parameters:
24879 Name for this group of servers.
24881 @item @code{servers}
24882 Specify the addresses of the servers in the group. The address can be
24883 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
24884 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
24885 prefix @samp{unix:}. For addresses using an IP address or domain name,
24886 the default port is 80, and a different port can be specified
24892 @deftp {Data Type} nginx-location-configuration
24893 Data type representing the configuration of an nginx @code{location}
24894 block. This type has the following parameters:
24898 URI which this location block matches.
24900 @anchor{nginx-location-configuration body}
24902 Body of the location block, specified as a list of strings. This can contain
24904 configuration directives. For example, to pass requests to a upstream
24905 server group defined using an @code{nginx-upstream-configuration} block,
24906 the following directive would be specified in the body @samp{(list "proxy_pass
24907 http://upstream-name;")}.
24912 @deftp {Data Type} nginx-named-location-configuration
24913 Data type representing the configuration of an nginx named location
24914 block. Named location blocks are used for request redirection, and not
24915 used for regular request processing. This type has the following
24920 Name to identify this location block.
24923 @xref{nginx-location-configuration body}, as the body for named location
24924 blocks can be used in a similar way to the
24925 @code{nginx-location-configuration body}. One restriction is that the
24926 body of a named location block cannot contain location blocks.
24931 @subsubheading Varnish Cache
24933 Varnish is a fast cache server that sits in between web applications
24934 and end users. It proxies requests from clients and caches the
24935 accessed URLs such that multiple requests for the same resource only
24936 creates one request to the back-end.
24938 @defvr {Scheme Variable} varnish-service-type
24939 Service type for the Varnish daemon.
24942 @deftp {Data Type} varnish-configuration
24943 Data type representing the @code{varnish} service configuration.
24944 This type has the following parameters:
24947 @item @code{package} (default: @code{varnish})
24948 The Varnish package to use.
24950 @item @code{name} (default: @code{"default"})
24951 A name for this Varnish instance. Varnish will create a directory in
24952 @file{/var/varnish/} with this name and keep temporary files there. If
24953 the name starts with a forward slash, it is interpreted as an absolute
24956 Pass the @code{-n} argument to other Varnish programs to connect to the
24957 named instance, e.g.@: @command{varnishncsa -n default}.
24959 @item @code{backend} (default: @code{"localhost:8080"})
24960 The backend to use. This option has no effect if @code{vcl} is set.
24962 @item @code{vcl} (default: #f)
24963 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
24964 is @code{#f}, Varnish will proxy @code{backend} using the default
24965 configuration. Otherwise this must be a file-like object with valid
24968 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
24969 For example, to mirror @url{https://www.gnu.org,www.gnu.org} with VCL you
24970 can do something along these lines:
24973 (define %gnu-mirror
24974 (plain-file "gnu.vcl"
24976 backend gnu @{ .host = \"www.gnu.org\"; @}"))
24980 (services (cons (service varnish-service-type
24981 (varnish-configuration
24983 (vcl %gnu-mirror)))
24987 The configuration of an already running Varnish instance can be inspected
24988 and changed using the @command{varnishadm} program.
24990 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
24991 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
24992 comprehensive documentation on Varnish and its configuration language.
24994 @item @code{listen} (default: @code{'("localhost:80")})
24995 List of addresses Varnish will listen on.
24997 @item @code{storage} (default: @code{'("malloc,128m")})
24998 List of storage backends that will be available in VCL.
25000 @item @code{parameters} (default: @code{'()})
25001 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
25003 @item @code{extra-options} (default: @code{'()})
25004 Additional arguments to pass to the @command{varnishd} process.
25009 @subsubheading Patchwork
25011 Patchwork is a patch tracking system. It can collect patches sent to a
25012 mailing list, and display them in a web interface.
25014 @defvr {Scheme Variable} patchwork-service-type
25015 Service type for Patchwork.
25018 The following example is an example of a minimal service for Patchwork, for
25019 the @code{patchwork.example.com} domain.
25022 (service patchwork-service-type
25023 (patchwork-configuration
25024 (domain "patchwork.example.com")
25026 (patchwork-settings-module
25027 (allowed-hosts (list domain))
25028 (default-from-email "patchwork@@patchwork.example.com")))
25029 (getmail-retriever-config
25030 (getmail-retriever-configuration
25031 (type "SimpleIMAPSSLRetriever")
25032 (server "imap.example.com")
25034 (username "patchwork")
25036 (list (file-append coreutils "/bin/cat")
25037 "/etc/getmail-patchwork-imap-password"))
25039 '((mailboxes . ("Patches"))))))))
25043 There are three records for configuring the Patchwork service. The
25044 @code{<patchwork-configuration>} relates to the configuration for Patchwork
25045 within the HTTPD service.
25047 The @code{settings-module} field within the @code{<patchwork-configuration>}
25048 record can be populated with the @code{<patchwork-settings-module>} record,
25049 which describes a settings module that is generated within the Guix store.
25051 For the @code{database-configuration} field within the
25052 @code{<patchwork-settings-module>}, the
25053 @code{<patchwork-database-configuration>} must be used.
25055 @deftp {Data Type} patchwork-configuration
25056 Data type representing the Patchwork service configuration. This type has the
25057 following parameters:
25060 @item @code{patchwork} (default: @code{patchwork})
25061 The Patchwork package to use.
25063 @item @code{domain}
25064 The domain to use for Patchwork, this is used in the HTTPD service virtual
25067 @item @code{settings-module}
25068 The settings module to use for Patchwork. As a Django application, Patchwork
25069 is configured with a Python module containing the settings. This can either be
25070 an instance of the @code{<patchwork-settings-module>} record, any other record
25071 that represents the settings in the store, or a directory outside of the
25074 @item @code{static-path} (default: @code{"/static/"})
25075 The path under which the HTTPD service should serve the static files.
25077 @item @code{getmail-retriever-config}
25078 The getmail-retriever-configuration record value to use with
25079 Patchwork. Getmail will be configured with this value, the messages will be
25080 delivered to Patchwork.
25085 @deftp {Data Type} patchwork-settings-module
25086 Data type representing a settings module for Patchwork. Some of these
25087 settings relate directly to Patchwork, but others relate to Django, the web
25088 framework used by Patchwork, or the Django Rest Framework library. This type
25089 has the following parameters:
25092 @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
25093 The database connection settings used for Patchwork. See the
25094 @code{<patchwork-database-configuration>} record type for more information.
25096 @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
25097 Patchwork, as a Django web application uses a secret key for cryptographically
25098 signing values. This file should contain a unique unpredictable value.
25100 If this file does not exist, it will be created and populated with a random
25101 value by the patchwork-setup shepherd service.
25103 This setting relates to Django.
25105 @item @code{allowed-hosts}
25106 A list of valid hosts for this Patchwork service. This should at least include
25107 the domain specified in the @code{<patchwork-configuration>} record.
25109 This is a Django setting.
25111 @item @code{default-from-email}
25112 The email address from which Patchwork should send email by default.
25114 This is a Patchwork setting.
25116 @item @code{static-url} (default: @code{#f})
25117 The URL to use when serving static assets. It can be part of a URL, or a full
25118 URL, but must end in a @code{/}.
25120 If the default value is used, the @code{static-path} value from the
25121 @code{<patchwork-configuration>} record will be used.
25123 This is a Django setting.
25125 @item @code{admins} (default: @code{'()})
25126 Email addresses to send the details of errors that occur. Each value should
25127 be a list containing two elements, the name and then the email address.
25129 This is a Django setting.
25131 @item @code{debug?} (default: @code{#f})
25132 Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
25133 messages will be shown.
25135 This is a Django setting.
25137 @item @code{enable-rest-api?} (default: @code{#t})
25138 Whether to enable the Patchwork REST API.
25140 This is a Patchwork setting.
25142 @item @code{enable-xmlrpc?} (default: @code{#t})
25143 Whether to enable the XML RPC API.
25145 This is a Patchwork setting.
25147 @item @code{force-https-links?} (default: @code{#t})
25148 Whether to use HTTPS links on Patchwork pages.
25150 This is a Patchwork setting.
25152 @item @code{extra-settings} (default: @code{""})
25153 Extra code to place at the end of the Patchwork settings module.
25158 @deftp {Data Type} patchwork-database-configuration
25159 Data type representing the database configuration for Patchwork.
25162 @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
25163 The database engine to use.
25165 @item @code{name} (default: @code{"patchwork"})
25166 The name of the database to use.
25168 @item @code{user} (default: @code{"httpd"})
25169 The user to connect to the database as.
25171 @item @code{password} (default: @code{""})
25172 The password to use when connecting to the database.
25174 @item @code{host} (default: @code{""})
25175 The host to make the database connection to.
25177 @item @code{port} (default: @code{""})
25178 The port on which to connect to the database.
25183 @subsubheading Mumi
25185 @cindex Mumi, Debbugs Web interface
25186 @cindex Debbugs, Mumi Web interface
25187 @uref{https://git.elephly.net/gitweb.cgi?p=software/mumi.git, Mumi} is a
25188 Web interface to the Debbugs bug tracker, by default for
25189 @uref{https://bugs.gnu.org, the GNU instance}. Mumi is a Web server,
25190 but it also fetches and indexes mail retrieved from Debbugs.
25192 @defvr {Scheme Variable} mumi-service-type
25193 This is the service type for Mumi.
25196 @deftp {Data Type} mumi-configuration
25197 Data type representing the Mumi service configuration. This type has the
25201 @item @code{mumi} (default: @code{mumi})
25202 The Mumi package to use.
25204 @item @code{mailer?} (default: @code{#true})
25205 Whether to enable or disable the mailer component.
25207 @item @code{mumi-configuration-sender}
25208 The email address used as the sender for comments.
25210 @item @code{mumi-configuration-smtp}
25211 A URI to configure the SMTP settings for Mailutils. This could be
25212 something like @code{sendmail:///path/to/bin/msmtp} or any other URI
25213 supported by Mailutils. @xref{SMTP Mailboxes, SMTP Mailboxes,,
25214 mailutils, GNU@tie{}Mailutils}.
25220 @subsubheading FastCGI
25223 FastCGI is an interface between the front-end and the back-end of a web
25224 service. It is a somewhat legacy facility; new web services should
25225 generally just talk HTTP between the front-end and the back-end.
25226 However there are a number of back-end services such as PHP or the
25227 optimized HTTP Git repository access that use FastCGI, so we have
25228 support for it in Guix.
25230 To use FastCGI, you configure the front-end web server (e.g., nginx) to
25231 dispatch some subset of its requests to the fastcgi backend, which
25232 listens on a local TCP or UNIX socket. There is an intermediary
25233 @code{fcgiwrap} program that sits between the actual backend process and
25234 the web server. The front-end indicates which backend program to run,
25235 passing that information to the @code{fcgiwrap} process.
25237 @defvr {Scheme Variable} fcgiwrap-service-type
25238 A service type for the @code{fcgiwrap} FastCGI proxy.
25241 @deftp {Data Type} fcgiwrap-configuration
25242 Data type representing the configuration of the @code{fcgiwrap} service.
25243 This type has the following parameters:
25245 @item @code{package} (default: @code{fcgiwrap})
25246 The fcgiwrap package to use.
25248 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
25249 The socket on which the @code{fcgiwrap} process should listen, as a
25250 string. Valid @var{socket} values include
25251 @code{unix:@var{/path/to/unix/socket}},
25252 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
25253 @code{tcp6:[@var{ipv6_addr}]:port}.
25255 @item @code{user} (default: @code{fcgiwrap})
25256 @itemx @code{group} (default: @code{fcgiwrap})
25257 The user and group names, as strings, under which to run the
25258 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
25259 the user asks for the specific user or group names @code{fcgiwrap} that
25260 the corresponding user and/or group is present on the system.
25262 It is possible to configure a FastCGI-backed web service to pass HTTP
25263 authentication information from the front-end to the back-end, and to
25264 allow @code{fcgiwrap} to run the back-end process as a corresponding
25265 local user. To enable this capability on the back-end, run
25266 @code{fcgiwrap} as the @code{root} user and group. Note that this
25267 capability also has to be configured on the front-end as well.
25272 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
25273 with some additional features useful for sites of any size.
25275 These features include:
25277 @item Adaptive process spawning
25278 @item Basic statistics (similar to Apache's mod_status)
25279 @item Advanced process management with graceful stop/start
25280 @item Ability to start workers with different uid/gid/chroot/environment
25281 and different php.ini (replaces safe_mode)
25282 @item Stdout & stderr logging
25283 @item Emergency restart in case of accidental opcode cache destruction
25284 @item Accelerated upload support
25285 @item Support for a "slowlog"
25286 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
25287 a special function to finish request & flush all data while continuing to do
25288 something time-consuming (video converting, stats processing, etc.)
25290 ...@: and much more.
25292 @defvr {Scheme Variable} php-fpm-service-type
25293 A Service type for @code{php-fpm}.
25296 @deftp {Data Type} php-fpm-configuration
25297 Data Type for php-fpm service configuration.
25299 @item @code{php} (default: @code{php})
25300 The php package to use.
25301 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
25302 The address on which to accept FastCGI requests. Valid syntaxes are:
25304 @item @code{"ip.add.re.ss:port"}
25305 Listen on a TCP socket to a specific address on a specific port.
25306 @item @code{"port"}
25307 Listen on a TCP socket to all addresses on a specific port.
25308 @item @code{"/path/to/unix/socket"}
25309 Listen on a unix socket.
25312 @item @code{user} (default: @code{php-fpm})
25313 User who will own the php worker processes.
25314 @item @code{group} (default: @code{php-fpm})
25315 Group of the worker processes.
25316 @item @code{socket-user} (default: @code{php-fpm})
25317 User who can speak to the php-fpm socket.
25318 @item @code{socket-group} (default: @code{nginx})
25319 Group that can speak to the php-fpm socket.
25320 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
25321 The process id of the php-fpm process is written to this file
25322 once the service has started.
25323 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
25324 Log for the php-fpm master process.
25325 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
25326 Detailed settings for the php-fpm process manager.
25329 @item @code{<php-fpm-dynamic-process-manager-configuration>}
25330 @item @code{<php-fpm-static-process-manager-configuration>}
25331 @item @code{<php-fpm-on-demand-process-manager-configuration>}
25333 @item @code{display-errors} (default @code{#f})
25334 Determines whether php errors and warning should be sent to clients
25335 and displayed in their browsers.
25336 This is useful for local php development, but a security risk for public sites,
25337 as error messages can reveal passwords and personal data.
25338 @item @code{timezone} (default @code{#f})
25339 Specifies @code{php_admin_value[date.timezone]} parameter.
25340 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
25341 This file will log the @code{stderr} outputs of php worker processes.
25342 Can be set to @code{#f} to disable logging.
25343 @item @code{file} (default @code{#f})
25344 An optional override of the whole configuration.
25345 You can use the @code{mixed-text-file} function or an absolute filepath for it.
25346 @item @code{php-ini-file} (default @code{#f})
25347 An optional override of the default php settings.
25348 It may be any ``file-like'' object (@pxref{G-Expressions, file-like objects}).
25349 You can use the @code{mixed-text-file} function or an absolute filepath for it.
25351 For local development it is useful to set a higher timeout and memory
25352 limit for spawned php processes. This be accomplished with the
25353 following operating system configuration snippet:
25355 (define %local-php-ini
25356 (plain-file "php.ini"
25358 max_execution_time = 1800"))
25362 (services (cons (service php-fpm-service-type
25363 (php-fpm-configuration
25364 (php-ini-file %local-php-ini)))
25368 Consult the @url{https://www.php.net/manual/en/ini.core.php,core php.ini
25369 directives} for comprehensive documentation on the acceptable
25370 @file{php.ini} directives.
25374 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
25375 Data Type for the @code{dynamic} php-fpm process manager. With the
25376 @code{dynamic} process manager, spare worker processes are kept around
25377 based on it's configured limits.
25379 @item @code{max-children} (default: @code{5})
25380 Maximum of worker processes.
25381 @item @code{start-servers} (default: @code{2})
25382 How many worker processes should be started on start-up.
25383 @item @code{min-spare-servers} (default: @code{1})
25384 How many spare worker processes should be kept around at minimum.
25385 @item @code{max-spare-servers} (default: @code{3})
25386 How many spare worker processes should be kept around at maximum.
25390 @deftp {Data type} php-fpm-static-process-manager-configuration
25391 Data Type for the @code{static} php-fpm process manager. With the
25392 @code{static} process manager, an unchanging number of worker processes
25395 @item @code{max-children} (default: @code{5})
25396 Maximum of worker processes.
25400 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
25401 Data Type for the @code{on-demand} php-fpm process manager. With the
25402 @code{on-demand} process manager, worker processes are only created as
25405 @item @code{max-children} (default: @code{5})
25406 Maximum of worker processes.
25407 @item @code{process-idle-timeout} (default: @code{10})
25408 The time in seconds after which a process with no requests is killed.
25413 @deffn {Scheme Procedure} nginx-php-location @
25414 [#:nginx-package nginx] @
25415 [socket (string-append "/var/run/php" @
25416 (version-major (package-version php)) @
25418 A helper function to quickly add php to an @code{nginx-server-configuration}.
25421 A simple services setup for nginx with php can look like this:
25423 (services (cons* (service dhcp-client-service-type)
25424 (service php-fpm-service-type)
25425 (service nginx-service-type
25426 (nginx-server-configuration
25427 (server-name '("example.com"))
25428 (root "/srv/http/")
25430 (list (nginx-php-location)))
25432 (ssl-certificate #f)
25433 (ssl-certificate-key #f)))
25437 @cindex cat-avatar-generator
25438 The cat avatar generator is a simple service to demonstrate the use of php-fpm
25439 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
25440 the hash of a user's email address.
25442 @deffn {Scheme Procedure} cat-avatar-generator-service @
25443 [#:cache-dir "/var/cache/cat-avatar-generator"] @
25444 [#:package cat-avatar-generator] @
25445 [#:configuration (nginx-server-configuration)]
25446 Returns an nginx-server-configuration that inherits @code{configuration}. It
25447 extends the nginx configuration to add a server block that serves @code{package},
25448 a version of cat-avatar-generator. During execution, cat-avatar-generator will
25449 be able to use @code{cache-dir} as its cache directory.
25452 A simple setup for cat-avatar-generator can look like this:
25454 (services (cons* (cat-avatar-generator-service
25456 (nginx-server-configuration
25457 (server-name '("example.com"))))
25462 @subsubheading Hpcguix-web
25464 @cindex hpcguix-web
25465 The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
25466 program is a customizable web interface to browse Guix packages,
25467 initially designed for users of high-performance computing (HPC)
25470 @defvr {Scheme Variable} hpcguix-web-service-type
25471 The service type for @code{hpcguix-web}.
25474 @deftp {Data Type} hpcguix-web-configuration
25475 Data type for the hpcguix-web service configuration.
25479 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
25480 configuration. The main items available in this spec are:
25483 @item @code{title-prefix} (default: @code{"hpcguix | "})
25484 The page title prefix.
25486 @item @code{guix-command} (default: @code{"guix"})
25487 The @command{guix} command.
25489 @item @code{package-filter-proc} (default: @code{(const #t)})
25490 A procedure specifying how to filter packages that are displayed.
25492 @item @code{package-page-extension-proc} (default: @code{(const '())})
25493 Extension package for @code{hpcguix-web}.
25495 @item @code{menu} (default: @code{'()})
25496 Additional entry in page @code{menu}.
25498 @item @code{channels} (default: @code{%default-channels})
25499 List of channels from which the package list is built (@pxref{Channels}).
25501 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
25502 The expiration time, in seconds, after which the package list is rebuilt from
25503 the latest instances of the given channels.
25506 See the hpcguix-web repository for a
25507 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
25510 @item @code{package} (default: @code{hpcguix-web})
25511 The hpcguix-web package to use.
25515 A typical hpcguix-web service declaration looks like this:
25518 (service hpcguix-web-service-type
25519 (hpcguix-web-configuration
25521 #~(define site-config
25522 (hpcweb-configuration
25523 (title-prefix "Guix-HPC - ")
25524 (menu '(("/about" "ABOUT"))))))))
25528 The hpcguix-web service periodically updates the package list it publishes by
25529 pulling channels from Git. To that end, it needs to access X.509 certificates
25530 so that it can authenticate Git servers when communicating over HTTPS, and it
25531 assumes that @file{/etc/ssl/certs} contains those certificates.
25533 Thus, make sure to add @code{nss-certs} or another certificate package to the
25534 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
25535 more information on X.509 certificates.
25538 @subsubheading gmnisrv
25541 The @uref{https://git.sr.ht/~sircmpwn/gmnisrv, gmnisrv} program is a
25542 simple @uref{https://gemini.circumlunar.space/, Gemini} protocol server.
25544 @deffn {Scheme Variable} gmnisrv-service-type
25545 This is the type of the gmnisrv service, whose value should be a
25546 @code{gmnisrv-configuration} object, as in this example:
25549 (service gmnisrv-service-type
25550 (gmnisrv-configuration
25551 (config-file (local-file "./my-gmnisrv.ini"))))
25555 @deftp {Data Type} gmnisrv-configuration
25556 Data type representing the configuration of gmnisrv.
25559 @item @code{package} (default: @var{gmnisrv})
25560 Package object of the gmnisrv server.
25562 @item @code{config-file} (default: @code{%default-gmnisrv-config-file})
25563 File-like object of the gmnisrv configuration file to use. The default
25564 configuration listens on port 1965 and serves files from
25565 @file{/srv/gemini}. Certificates are stored in
25566 @file{/var/lib/gemini/certs}. For more information, run @command{man
25567 gmnisrv} and @command{man gmnisrv.ini}.
25572 @subsubheading Agate
25575 The @uref{gemini://qwertqwefsday.eu/agate.gmi, Agate}
25576 (@uref{https://github.com/mbrubeck/agate, GitHub page over HTTPS})
25577 program is a simple @uref{https://gemini.circumlunar.space/, Gemini}
25578 protocol server written in Rust.
25580 @deffn {Scheme Variable} agate-service-type
25581 This is the type of the agate service, whose value should be an
25582 @code{agate-service-type} object, as in this example:
25585 (service agate-service-type
25586 (agate-configuration
25587 (content "/srv/gemini")
25588 (cert "/srv/cert.pem")
25589 (key "/srv/key.rsa")))
25592 The example above represents the minimal tweaking necessary to get Agate
25593 up and running. Specifying the path to the certificate and key is
25594 always necessary, as the Gemini protocol requires TLS by default.
25596 To obtain a certificate and a key, you could, for example, use OpenSSL,
25597 running a command similar to the following example:
25600 openssl req -x509 -newkey rsa:4096 -keyout key.rsa -out cert.pem \
25601 -days 3650 -nodes -subj "/CN=example.com"
25604 Of course, you'll have to replace @i{example.com} with your own domain
25605 name, and then point the Agate configuration towards the path of the
25606 generated key and certificate.
25610 @deftp {Data Type} agate-configuration
25611 Data type representing the configuration of Agate.
25614 @item @code{package} (default: @code{agate})
25615 The package object of the Agate server.
25617 @item @code{content} (default: @file{"/srv/gemini"})
25618 The directory from which Agate will serve files.
25620 @item @code{cert} (default: @code{#f})
25621 The path to the TLS certificate PEM file to be used for encrypted
25622 connections. Must be filled in with a value from the user.
25624 @item @code{key} (default: @code{#f})
25625 The path to the PKCS8 private key file to be used for encrypted
25626 connections. Must be filled in with a value from the user.
25628 @item @code{addr} (default: @code{'("0.0.0.0:1965" "[::]:1965")})
25629 A list of the addresses to listen on.
25631 @item @code{hostname} (default: @code{#f})
25632 The domain name of this Gemini server. Optional.
25634 @item @code{lang} (default: @code{#f})
25635 RFC 4646 language code(s) for text/gemini documents. Optional.
25637 @item @code{silent?} (default: @code{#f})
25638 Set to @code{#t} to disable logging output.
25640 @item @code{serve-secret?} (default: @code{#f})
25641 Set to @code{#t} to serve secret files (files/directories starting with
25644 @item @code{log-ip?} (default: @code{#t})
25645 Whether or not to output IP addresses when logging.
25647 @item @code{user} (default: @code{"agate"})
25648 Owner of the @code{agate} process.
25650 @item @code{group} (default: @code{"agate"})
25651 Owner's group of the @code{agate} process.
25653 @item @code{log-file} (default: @file{"/var/log/agate.log"})
25654 The file which should store the logging output of Agate.
25659 @node Certificate Services
25660 @subsection Certificate Services
25663 @cindex HTTP, HTTPS
25664 @cindex Let's Encrypt
25665 @cindex TLS certificates
25666 The @code{(gnu services certbot)} module provides a service to
25667 automatically obtain a valid TLS certificate from the Let's Encrypt
25668 certificate authority. These certificates can then be used to serve
25669 content securely over HTTPS or other TLS-based protocols, with the
25670 knowledge that the client will be able to verify the server's
25673 @url{https://letsencrypt.org/, Let's Encrypt} provides the
25674 @code{certbot} tool to automate the certification process. This tool
25675 first securely generates a key on the server. It then makes a request
25676 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
25677 checks that the request originates from the host in question by using a
25678 challenge-response protocol, requiring the server to provide its
25679 response over HTTP@. If that protocol completes successfully, the CA
25680 signs the key, resulting in a certificate. That certificate is valid
25681 for a limited period of time, and therefore to continue to provide TLS
25682 services, the server needs to periodically ask the CA to renew its
25685 The certbot service automates this process: the initial key
25686 generation, the initial certification request to the Let's Encrypt
25687 service, the web server challenge/response integration, writing the
25688 certificate to disk, the automated periodic renewals, and the deployment
25689 tasks associated with the renewal (e.g.@: reloading services, copying keys
25690 with different permissions).
25692 Certbot is run twice a day, at a random minute within the hour. It
25693 won't do anything until your certificates are due for renewal or
25694 revoked, but running it regularly would give your service a chance of
25695 staying online in case a Let's Encrypt-initiated revocation happened for
25698 By using this service, you agree to the ACME Subscriber Agreement, which
25699 can be found there:
25700 @url{https://acme-v01.api.letsencrypt.org/directory}.
25702 @defvr {Scheme Variable} certbot-service-type
25703 A service type for the @code{certbot} Let's Encrypt client. Its value
25704 must be a @code{certbot-configuration} record as in this example:
25707 (define %nginx-deploy-hook
25709 "nginx-deploy-hook"
25710 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
25711 (kill pid SIGHUP))))
25713 (service certbot-service-type
25714 (certbot-configuration
25715 (email "foo@@example.net")
25718 (certificate-configuration
25719 (domains '("example.net" "www.example.net"))
25720 (deploy-hook %nginx-deploy-hook))
25721 (certificate-configuration
25722 (domains '("bar.example.net")))))))
25725 See below for details about @code{certbot-configuration}.
25728 @deftp {Data Type} certbot-configuration
25729 Data type representing the configuration of the @code{certbot} service.
25730 This type has the following parameters:
25733 @item @code{package} (default: @code{certbot})
25734 The certbot package to use.
25736 @item @code{webroot} (default: @code{/var/www})
25737 The directory from which to serve the Let's Encrypt challenge/response
25740 @item @code{certificates} (default: @code{()})
25741 A list of @code{certificates-configuration}s for which to generate
25742 certificates and request signatures. Each certificate has a @code{name}
25743 and several @code{domains}.
25745 @item @code{email} (default: @code{#f})
25746 Optional email address used for registration and recovery contact.
25747 Setting this is encouraged as it allows you to receive important
25748 notifications about the account and issued certificates.
25750 @item @code{server} (default: @code{#f})
25751 Optional URL of ACME server. Setting this overrides certbot's default,
25752 which is the Let's Encrypt server.
25754 @item @code{rsa-key-size} (default: @code{2048})
25755 Size of the RSA key.
25757 @item @code{default-location} (default: @i{see below})
25758 The default @code{nginx-location-configuration}. Because @code{certbot}
25759 needs to be able to serve challenges and responses, it needs to be able
25760 to run a web server. It does so by extending the @code{nginx} web
25761 service with an @code{nginx-server-configuration} listening on the
25762 @var{domains} on port 80, and which has a
25763 @code{nginx-location-configuration} for the @code{/.well-known/} URI
25764 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
25765 these nginx configuration data types.
25767 Requests to other URL paths will be matched by the
25768 @code{default-location}, which if present is added to all
25769 @code{nginx-server-configuration}s.
25771 By default, the @code{default-location} will issue a redirect from
25772 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
25773 you to define what to serve on your site via @code{https}.
25775 Pass @code{#f} to not issue a default location.
25779 @deftp {Data Type} certificate-configuration
25780 Data type representing the configuration of a certificate.
25781 This type has the following parameters:
25784 @item @code{name} (default: @i{see below})
25785 This name is used by Certbot for housekeeping and in file paths; it
25786 doesn't affect the content of the certificate itself. To see
25787 certificate names, run @code{certbot certificates}.
25789 Its default is the first provided domain.
25791 @item @code{domains} (default: @code{()})
25792 The first domain provided will be the subject CN of the certificate, and
25793 all domains will be Subject Alternative Names on the certificate.
25795 @item @code{challenge} (default: @code{#f})
25796 The challenge type that has to be run by certbot. If @code{#f} is specified,
25797 default to the HTTP challenge. If a value is specified, defaults to the
25798 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
25799 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}),
25800 and gives Let's Encrypt permission to log the public IP address of the
25801 requesting machine.
25803 @item @code{authentication-hook} (default: @code{#f})
25804 Command to be run in a shell once for each certificate challenge to be
25805 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
25806 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
25807 contains the validation string and @code{$CERTBOT_TOKEN} contains the
25808 file name of the resource requested when performing an HTTP-01 challenge.
25810 @item @code{cleanup-hook} (default: @code{#f})
25811 Command to be run in a shell once for each certificate challenge that
25812 have been answered by the @code{auth-hook}. For this command, the shell
25813 variables available in the @code{auth-hook} script are still available, and
25814 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
25815 of the @code{auth-hook} script.
25817 @item @code{deploy-hook} (default: @code{#f})
25818 Command to be run in a shell once for each successfully issued
25819 certificate. For this command, the shell variable
25820 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
25821 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
25822 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
25823 contain a space-delimited list of renewed certificate domains (for
25824 example, @samp{"example.com www.example.com"}.
25829 For each @code{certificate-configuration}, the certificate is saved to
25830 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
25831 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
25833 @subsection DNS Services
25834 @cindex DNS (domain name system)
25835 @cindex domain name system (DNS)
25837 The @code{(gnu services dns)} module provides services related to the
25838 @dfn{domain name system} (DNS). It provides a server service for hosting
25839 an @emph{authoritative} DNS server for multiple zones, slave or master.
25840 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
25841 caching and forwarding DNS server for the LAN, which uses
25842 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
25844 @subsubheading Knot Service
25846 An example configuration of an authoritative server for two zones, one master
25850 (define-zone-entries example.org.zone
25851 ;; Name TTL Class Type Data
25852 ("@@" "" "IN" "A" "127.0.0.1")
25853 ("@@" "" "IN" "NS" "ns")
25854 ("ns" "" "IN" "A" "127.0.0.1"))
25856 (define master-zone
25857 (knot-zone-configuration
25858 (domain "example.org")
25860 (origin "example.org")
25861 (entries example.org.zone)))))
25864 (knot-zone-configuration
25865 (domain "plop.org")
25866 (dnssec-policy "default")
25867 (master (list "plop-master"))))
25869 (define plop-master
25870 (knot-remote-configuration
25872 (address (list "208.76.58.171"))))
25876 (services (cons* (service knot-service-type
25877 (knot-configuration
25878 (remotes (list plop-master))
25879 (zones (list master-zone slave-zone))))
25884 @deffn {Scheme Variable} knot-service-type
25885 This is the type for the Knot DNS server.
25887 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
25888 zones, that is to say domain names you would buy from a registrar. This server
25889 is not a resolver, meaning that it can only resolve names for which it is
25890 authoritative. This server can be configured to serve zones as a master server
25891 or a slave server as a per-zone basis. Slave zones will get their data from
25892 masters, and will serve it as an authoritative server. From the point of view
25893 of a resolver, there is no difference between master and slave.
25895 The following data types are used to configure the Knot DNS server:
25898 @deftp {Data Type} knot-key-configuration
25899 Data type representing a key.
25900 This type has the following parameters:
25903 @item @code{id} (default: @code{""})
25904 An identifier for other configuration fields to refer to this key. IDs must
25905 be unique and must not be empty.
25907 @item @code{algorithm} (default: @code{#f})
25908 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
25909 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
25910 and @code{'hmac-sha512}.
25912 @item @code{secret} (default: @code{""})
25913 The secret key itself.
25918 @deftp {Data Type} knot-acl-configuration
25919 Data type representing an Access Control List (ACL) configuration.
25920 This type has the following parameters:
25923 @item @code{id} (default: @code{""})
25924 An identifier for other configuration fields to refer to this key. IDs must be
25925 unique and must not be empty.
25927 @item @code{address} (default: @code{'()})
25928 An ordered list of IP addresses, network subnets, or network ranges represented
25929 with strings. The query must match one of them. Empty value means that
25930 address match is not required.
25932 @item @code{key} (default: @code{'()})
25933 An ordered list of references to keys represented with strings. The string
25934 must match a key ID defined in a @code{knot-key-configuration}. No key means
25935 that a key is not require to match that ACL.
25937 @item @code{action} (default: @code{'()})
25938 An ordered list of actions that are permitted or forbidden by this ACL@. Possible
25939 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
25940 and @code{'update}.
25942 @item @code{deny?} (default: @code{#f})
25943 When true, the ACL defines restrictions. Listed actions are forbidden. When
25944 false, listed actions are allowed.
25949 @deftp {Data Type} zone-entry
25950 Data type representing a record entry in a zone file.
25951 This type has the following parameters:
25954 @item @code{name} (default: @code{"@@"})
25955 The name of the record. @code{"@@"} refers to the origin of the zone. Names
25956 are relative to the origin of the zone. For example, in the @code{example.org}
25957 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
25958 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
25959 refers to @code{ns.example.org}.
25961 @item @code{ttl} (default: @code{""})
25962 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
25964 @item @code{class} (default: @code{"IN"})
25965 The class of the record. Knot currently supports only @code{"IN"} and
25966 partially @code{"CH"}.
25968 @item @code{type} (default: @code{"A"})
25969 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
25970 address), NS (Name Server) and MX (Mail eXchange). Many other types are
25973 @item @code{data} (default: @code{""})
25974 The data contained in the record. For instance an IP address associated with
25975 an A record, or a domain name associated with an NS record. Remember that
25976 domain names are relative to the origin unless they end with a dot.
25981 @deftp {Data Type} zone-file
25982 Data type representing the content of a zone file.
25983 This type has the following parameters:
25986 @item @code{entries} (default: @code{'()})
25987 The list of entries. The SOA record is taken care of, so you don't need to
25988 put it in the list of entries. This list should probably contain an entry
25989 for your primary authoritative DNS server. Other than using a list of entries
25990 directly, you can use @code{define-zone-entries} to define a object containing
25991 the list of entries more easily, that you can later pass to the @code{entries}
25992 field of the @code{zone-file}.
25994 @item @code{origin} (default: @code{""})
25995 The name of your zone. This parameter cannot be empty.
25997 @item @code{ns} (default: @code{"ns"})
25998 The domain of your primary authoritative DNS server. The name is relative to
25999 the origin, unless it ends with a dot. It is mandatory that this primary
26000 DNS server corresponds to an NS record in the zone and that it is associated
26001 to an IP address in the list of entries.
26003 @item @code{mail} (default: @code{"hostmaster"})
26004 An email address people can contact you at, as the owner of the zone. This
26005 is translated as @code{<mail>@@<origin>}.
26007 @item @code{serial} (default: @code{1})
26008 The serial number of the zone. As this is used to keep track of changes by
26009 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
26010 Always increment it when you make a change in your zone.
26012 @item @code{refresh} (default: @code{(* 2 24 3600)})
26013 The frequency at which slaves will do a zone transfer. This value is a number
26014 of seconds. It can be computed by multiplications or with
26015 @code{(string->duration)}.
26017 @item @code{retry} (default: @code{(* 15 60)})
26018 The period after which a slave will retry to contact its master when it fails
26019 to do so a first time.
26021 @item @code{expiry} (default: @code{(* 14 24 3600)})
26022 Default TTL of records. Existing records are considered correct for at most
26023 this amount of time. After this period, resolvers will invalidate their cache
26024 and check again that it still exists.
26026 @item @code{nx} (default: @code{3600})
26027 Default TTL of inexistent records. This delay is usually short because you want
26028 your new domains to reach everyone quickly.
26033 @deftp {Data Type} knot-remote-configuration
26034 Data type representing a remote configuration.
26035 This type has the following parameters:
26038 @item @code{id} (default: @code{""})
26039 An identifier for other configuration fields to refer to this remote. IDs must
26040 be unique and must not be empty.
26042 @item @code{address} (default: @code{'()})
26043 An ordered list of destination IP addresses. Addresses are tried in sequence.
26044 An optional port can be given with the @@ separator. For instance:
26045 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
26047 @item @code{via} (default: @code{'()})
26048 An ordered list of source IP addresses. An empty list will have Knot choose
26049 an appropriate source IP@. An optional port can be given with the @@ separator.
26050 The default is to choose at random.
26052 @item @code{key} (default: @code{#f})
26053 A reference to a key, that is a string containing the identifier of a key
26054 defined in a @code{knot-key-configuration} field.
26059 @deftp {Data Type} knot-keystore-configuration
26060 Data type representing a keystore to hold dnssec keys.
26061 This type has the following parameters:
26064 @item @code{id} (default: @code{""})
26065 The id of the keystore. It must not be empty.
26067 @item @code{backend} (default: @code{'pem})
26068 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
26070 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
26071 The configuration string of the backend. An example for the PKCS#11 is:
26072 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
26073 For the pem backend, the string represents a path in the file system.
26078 @deftp {Data Type} knot-policy-configuration
26079 Data type representing a dnssec policy. Knot DNS is able to automatically
26080 sign your zones. It can either generate and manage your keys automatically or
26081 use keys that you generate.
26083 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
26084 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
26085 zone. In order to be trusted, the KSK needs to be present in the parent zone
26086 (usually a top-level domain). If your registrar supports dnssec, you will
26087 have to send them your KSK's hash so they can add a DS record in their zone.
26088 This is not automated and need to be done each time you change your KSK.
26090 The policy also defines the lifetime of keys. Usually, ZSK can be changed
26091 easily and use weaker cryptographic functions (they use lower parameters) in
26092 order to sign records quickly, so they are changed often. The KSK however
26093 requires manual interaction with the registrar, so they are changed less often
26094 and use stronger parameters because they sign only one record.
26096 This type has the following parameters:
26099 @item @code{id} (default: @code{""})
26100 The id of the policy. It must not be empty.
26102 @item @code{keystore} (default: @code{"default"})
26103 A reference to a keystore, that is a string containing the identifier of a
26104 keystore defined in a @code{knot-keystore-configuration} field. The
26105 @code{"default"} identifier means the default keystore (a kasp database that
26106 was setup by this service).
26108 @item @code{manual?} (default: @code{#f})
26109 Whether the key management is manual or automatic.
26111 @item @code{single-type-signing?} (default: @code{#f})
26112 When @code{#t}, use the Single-Type Signing Scheme.
26114 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
26115 An algorithm of signing keys and issued signatures.
26117 @item @code{ksk-size} (default: @code{256})
26118 The length of the KSK@. Note that this value is correct for the default
26119 algorithm, but would be unsecure for other algorithms.
26121 @item @code{zsk-size} (default: @code{256})
26122 The length of the ZSK@. Note that this value is correct for the default
26123 algorithm, but would be unsecure for other algorithms.
26125 @item @code{dnskey-ttl} (default: @code{'default})
26126 The TTL value for DNSKEY records added into zone apex. The special
26127 @code{'default} value means same as the zone SOA TTL.
26129 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
26130 The period between ZSK publication and the next rollover initiation.
26132 @item @code{propagation-delay} (default: @code{(* 24 3600)})
26133 An extra delay added for each key rollover step. This value should be high
26134 enough to cover propagation of data from the master server to all slaves.
26136 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
26137 A validity period of newly issued signatures.
26139 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
26140 A period how long before a signature expiration the signature will be refreshed.
26142 @item @code{nsec3?} (default: @code{#f})
26143 When @code{#t}, NSEC3 will be used instead of NSEC.
26145 @item @code{nsec3-iterations} (default: @code{5})
26146 The number of additional times the hashing is performed.
26148 @item @code{nsec3-salt-length} (default: @code{8})
26149 The length of a salt field in octets, which is appended to the original owner
26150 name before hashing.
26152 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
26153 The validity period of newly issued salt field.
26158 @deftp {Data Type} knot-zone-configuration
26159 Data type representing a zone served by Knot.
26160 This type has the following parameters:
26163 @item @code{domain} (default: @code{""})
26164 The domain served by this configuration. It must not be empty.
26166 @item @code{file} (default: @code{""})
26167 The file where this zone is saved. This parameter is ignored by master zones.
26168 Empty means default location that depends on the domain name.
26170 @item @code{zone} (default: @code{(zone-file)})
26171 The content of the zone file. This parameter is ignored by slave zones. It
26172 must contain a zone-file record.
26174 @item @code{master} (default: @code{'()})
26175 A list of master remotes. When empty, this zone is a master. When set, this
26176 zone is a slave. This is a list of remotes identifiers.
26178 @item @code{ddns-master} (default: @code{#f})
26179 The main master. When empty, it defaults to the first master in the list of
26182 @item @code{notify} (default: @code{'()})
26183 A list of slave remote identifiers.
26185 @item @code{acl} (default: @code{'()})
26186 A list of acl identifiers.
26188 @item @code{semantic-checks?} (default: @code{#f})
26189 When set, this adds more semantic checks to the zone.
26191 @item @code{disable-any?} (default: @code{#f})
26192 When set, this forbids queries of the ANY type.
26194 @item @code{zonefile-sync} (default: @code{0})
26195 The delay between a modification in memory and on disk. 0 means immediate
26198 @item @code{zonefile-load} (default: @code{#f})
26199 The way the zone file contents are applied during zone load. Possible values
26203 @item @code{#f} for using the default value from Knot,
26204 @item @code{'none} for not using the zone file at all,
26205 @item @code{'difference} for computing the difference between already available
26206 contents and zone contents and applying it to the current zone contents,
26207 @item @code{'difference-no-serial} for the same as @code{'difference}, but
26208 ignoring the SOA serial in the zone file, while the server takes care of it
26210 @item @code{'whole} for loading zone contents from the zone file.
26213 @item @code{journal-content} (default: @code{#f})
26214 The way the journal is used to store zone and its changes. Possible values
26215 are @code{'none} to not use it at all, @code{'changes} to store changes and
26216 @code{'all} to store contents. @code{#f} does not set this option, so the
26217 default value from Knot is used.
26219 @item @code{max-journal-usage} (default: @code{#f})
26220 The maximum size for the journal on disk. @code{#f} does not set this option,
26221 so the default value from Knot is used.
26223 @item @code{max-journal-depth} (default: @code{#f})
26224 The maximum size of the history. @code{#f} does not set this option, so the
26225 default value from Knot is used.
26227 @item @code{max-zone-size} (default: @code{#f})
26228 The maximum size of the zone file. This limit is enforced for incoming
26229 transfer and updates. @code{#f} does not set this option, so the default
26230 value from Knot is used.
26232 @item @code{dnssec-policy} (default: @code{#f})
26233 A reference to a @code{knot-policy-configuration} record, or the special
26234 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
26237 @item @code{serial-policy} (default: @code{'increment})
26238 A policy between @code{'increment} and @code{'unixtime}.
26243 @deftp {Data Type} knot-configuration
26244 Data type representing the Knot configuration.
26245 This type has the following parameters:
26248 @item @code{knot} (default: @code{knot})
26251 @item @code{run-directory} (default: @code{"/var/run/knot"})
26252 The run directory. This directory will be used for pid file and sockets.
26254 @item @code{includes} (default: @code{'()})
26255 A list of strings or file-like objects denoting other files that must be
26256 included at the top of the configuration file.
26258 @cindex secrets, Knot service
26259 This can be used to manage secrets out-of-band. For example, secret
26260 keys may be stored in an out-of-band file not managed by Guix, and
26261 thus not visible in @file{/gnu/store}---e.g., you could store secret
26262 key configuration in @file{/etc/knot/secrets.conf} and add this file
26263 to the @code{includes} list.
26265 One can generate a secret tsig key (for nsupdate and zone transfers with the
26266 keymgr command from the knot package. Note that the package is not automatically
26267 installed by the service. The following example shows how to generate a new
26271 keymgr -t mysecret > /etc/knot/secrets.conf
26272 chmod 600 /etc/knot/secrets.conf
26275 Also note that the generated key will be named @var{mysecret}, so it is the
26276 name that needs to be used in the @var{key} field of the
26277 @code{knot-acl-configuration} record and in other places that need to refer
26280 It can also be used to add configuration not supported by this interface.
26282 @item @code{listen-v4} (default: @code{"0.0.0.0"})
26283 An ip address on which to listen.
26285 @item @code{listen-v6} (default: @code{"::"})
26286 An ip address on which to listen.
26288 @item @code{listen-port} (default: @code{53})
26289 A port on which to listen.
26291 @item @code{keys} (default: @code{'()})
26292 The list of knot-key-configuration used by this configuration.
26294 @item @code{acls} (default: @code{'()})
26295 The list of knot-acl-configuration used by this configuration.
26297 @item @code{remotes} (default: @code{'()})
26298 The list of knot-remote-configuration used by this configuration.
26300 @item @code{zones} (default: @code{'()})
26301 The list of knot-zone-configuration used by this configuration.
26306 @subsubheading Knot Resolver Service
26308 @deffn {Scheme Variable} knot-resolver-service-type
26309 This is the type of the knot resolver service, whose value should be
26310 an @code{knot-resolver-configuration} object as in this example:
26313 (service knot-resolver-service-type
26314 (knot-resolver-configuration
26315 (kresd-config-file (plain-file "kresd.conf" "
26316 net.listen('192.168.0.1', 5353)
26317 user('knot-resolver', 'knot-resolver')
26318 modules = @{ 'hints > iterate', 'stats', 'predict' @}
26319 cache.size = 100 * MB
26323 For more information, refer its @url{https://knot-resolver.readthedocs.org/en/stable/daemon.html#configuration, manual}.
26326 @deftp {Data Type} knot-resolver-configuration
26327 Data type representing the configuration of knot-resolver.
26330 @item @code{package} (default: @var{knot-resolver})
26331 Package object of the knot DNS resolver.
26333 @item @code{kresd-config-file} (default: %kresd.conf)
26334 File-like object of the kresd configuration file to use, by default it
26335 will listen on @code{127.0.0.1} and @code{::1}.
26337 @item @code{garbage-collection-interval} (default: 1000)
26338 Number of milliseconds for @code{kres-cache-gc} to periodically trim the cache.
26344 @subsubheading Dnsmasq Service
26346 @deffn {Scheme Variable} dnsmasq-service-type
26347 This is the type of the dnsmasq service, whose value should be an
26348 @code{dnsmasq-configuration} object as in this example:
26351 (service dnsmasq-service-type
26352 (dnsmasq-configuration
26354 (servers '("192.168.1.1"))))
26358 @deftp {Data Type} dnsmasq-configuration
26359 Data type representing the configuration of dnsmasq.
26362 @item @code{package} (default: @var{dnsmasq})
26363 Package object of the dnsmasq server.
26365 @item @code{no-hosts?} (default: @code{#f})
26366 When true, don't read the hostnames in /etc/hosts.
26368 @item @code{port} (default: @code{53})
26369 The port to listen on. Setting this to zero completely disables DNS
26370 responses, leaving only DHCP and/or TFTP functions.
26372 @item @code{local-service?} (default: @code{#t})
26373 Accept DNS queries only from hosts whose address is on a local subnet,
26374 ie a subnet for which an interface exists on the server.
26376 @item @code{listen-addresses} (default: @code{'()})
26377 Listen on the given IP addresses.
26379 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
26380 The file to read the IP address of the upstream nameservers from.
26382 @item @code{no-resolv?} (default: @code{#f})
26383 When true, don't read @var{resolv-file}.
26385 @item @code{servers} (default: @code{'()})
26386 Specify IP address of upstream servers directly.
26388 @item @code{addresses} (default: @code{'()})
26389 For each entry, specify an IP address to return for any host in the
26390 given domains. Queries in the domains are never forwarded and always
26391 replied to with the specified IP address.
26393 This is useful for redirecting hosts locally, for example:
26396 (service dnsmasq-service-type
26397 (dnsmasq-configuration
26399 '(; Redirect to a local web-server.
26400 "/example.org/127.0.0.1"
26401 ; Redirect subdomain to a specific IP.
26402 "/subdomain.example.org/192.168.1.42"))))
26405 Note that rules in @file{/etc/hosts} take precedence over this.
26407 @item @code{cache-size} (default: @code{150})
26408 Set the size of dnsmasq's cache. Setting the cache size to zero
26411 @item @code{negative-cache?} (default: @code{#t})
26412 When false, disable negative caching.
26414 @item @code{tftp-enable?} (default: @code{#f})
26415 Whether to enable the built-in TFTP server.
26417 @item @code{tftp-no-fail?} (default: @code{#f})
26418 If true, does not fail dnsmasq if the TFTP server could not start up.
26420 @item @code{tftp-single-port?} (default: @code{#f})
26421 Whether to use only one single port for TFTP.
26423 @item @code{tftp-secure?} (default: @code{#f})
26424 If true, only files owned by the user running the dnsmasq process are accessible.
26426 If dnsmasq is being run as root, different rules apply:
26427 @code{tftp-secure?} has no effect, but only files which have the
26428 world-readable bit set are accessible.
26430 @item @code{tftp-max} (default: @code{#f})
26431 If set, sets the maximal number of concurrent connections allowed.
26433 @item @code{tftp-mtu} (default: @code{#f})
26434 If set, sets the MTU for TFTP packets to that value.
26436 @item @code{tftp-no-blocksize?} (default: @code{#f})
26437 If true, stops the TFTP server from negotiating the blocksize with a client.
26439 @item @code{tftp-lowercase?} (default: @code{#f})
26440 Whether to convert all filenames in TFTP requests to lowercase.
26442 @item @code{tftp-port-range} (default: @code{#f})
26443 If set, fixes the dynamical ports (one per client) to the given range
26444 (@code{"<start>,<end>"}).
26446 @item @code{tftp-root} (default: @code{/var/empty,lo})
26447 Look for files to transfer using TFTP relative to the given directory.
26448 When this is set, TFTP paths which include @samp{..} are rejected, to stop clients
26449 getting outside the specified root. Absolute paths (starting with @samp{/}) are
26450 allowed, but they must be within the TFTP-root. If the optional interface
26451 argument is given, the directory is only used for TFTP requests via that
26454 @item @code{tftp-unique-root} (default: @code{#f})
26455 If set, add the IP or hardware address of the TFTP client as a path component
26456 on the end of the TFTP-root. Only valid if a TFTP root is set and the
26457 directory exists. Defaults to adding IP address (in standard dotted-quad
26460 For instance, if @option{--tftp-root} is @samp{/tftp} and client
26461 @samp{1.2.3.4} requests file @file{myfile} then the effective path will
26462 be @file{/tftp/1.2.3.4/myfile} if @file{/tftp/1.2.3.4} exists or
26463 @file{/tftp/myfile} otherwise. When @samp{=mac} is specified it will
26464 append the MAC address instead, using lowercase zero padded digits
26465 separated by dashes, e.g.: @samp{01-02-03-04-aa-bb}. Note that
26466 resolving MAC addresses is only possible if the client is in the local
26467 network or obtained a DHCP lease from dnsmasq.
26472 @subsubheading ddclient Service
26475 The ddclient service described below runs the ddclient daemon, which takes
26476 care of automatically updating DNS entries for service providers such as
26477 @uref{https://dyn.com/dns/, Dyn}.
26479 The following example show instantiates the service with its default
26483 (service ddclient-service-type)
26486 Note that ddclient needs to access credentials that are stored in a
26487 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
26488 @code{secret-file} below). You are expected to create this file manually, in
26489 an ``out-of-band'' fashion (you @emph{could} make this file part of the
26490 service configuration, for instance by using @code{plain-file}, but it will be
26491 world-readable @i{via} @file{/gnu/store}). See the examples in the
26492 @file{share/ddclient} directory of the @code{ddclient} package.
26494 @c %start of fragment
26496 Available @code{ddclient-configuration} fields are:
26498 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
26499 The ddclient package.
26503 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
26504 The period after which ddclient will retry to check IP and domain name.
26506 Defaults to @samp{300}.
26510 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
26511 Use syslog for the output.
26513 Defaults to @samp{#t}.
26517 @deftypevr {@code{ddclient-configuration} parameter} string mail
26520 Defaults to @samp{"root"}.
26524 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
26525 Mail failed update to user.
26527 Defaults to @samp{"root"}.
26531 @deftypevr {@code{ddclient-configuration} parameter} string pid
26532 The ddclient PID file.
26534 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
26538 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
26539 Enable SSL support.
26541 Defaults to @samp{#t}.
26545 @deftypevr {@code{ddclient-configuration} parameter} string user
26546 Specifies the user name or ID that is used when running ddclient
26549 Defaults to @samp{"ddclient"}.
26553 @deftypevr {@code{ddclient-configuration} parameter} string group
26554 Group of the user who will run the ddclient program.
26556 Defaults to @samp{"ddclient"}.
26560 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
26561 Secret file which will be appended to @file{ddclient.conf} file. This
26562 file contains credentials for use by ddclient. You are expected to
26563 create it manually.
26565 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
26569 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
26570 Extra options will be appended to @file{ddclient.conf} file.
26572 Defaults to @samp{()}.
26577 @c %end of fragment
26581 @subsection VPN Services
26582 @cindex VPN (virtual private network)
26583 @cindex virtual private network (VPN)
26585 The @code{(gnu services vpn)} module provides services related to
26586 @dfn{virtual private networks} (VPNs).
26588 @subsubheading OpenVPN
26590 It provides a @emph{client} service for your machine to connect to a
26591 VPN, and a @emph{server} service for your machine to host a VPN@.
26593 @deffn {Scheme Procedure} openvpn-client-service @
26594 [#:config (openvpn-client-configuration)]
26596 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
26599 @deffn {Scheme Procedure} openvpn-server-service @
26600 [#:config (openvpn-server-configuration)]
26602 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
26604 Both can be run simultaneously.
26607 @c %automatically generated documentation
26609 Available @code{openvpn-client-configuration} fields are:
26611 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
26612 The OpenVPN package.
26616 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
26617 The OpenVPN pid file.
26619 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
26623 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
26624 The protocol (UDP or TCP) used to open a channel between clients and
26627 Defaults to @samp{udp}.
26631 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
26632 The device type used to represent the VPN connection.
26634 Defaults to @samp{tun}.
26638 If you do not have some of these files (eg.@: you use a username and
26639 password), you can disable any of the following three fields by setting
26640 it to @code{'disabled}.
26642 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string ca
26643 The certificate authority to check connections against.
26645 Defaults to @samp{"/etc/openvpn/ca.crt"}.
26649 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string cert
26650 The certificate of the machine the daemon is running on. It should be
26651 signed by the authority given in @code{ca}.
26653 Defaults to @samp{"/etc/openvpn/client.crt"}.
26657 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string key
26658 The key of the machine the daemon is running on. It must be the key whose
26659 certificate is @code{cert}.
26661 Defaults to @samp{"/etc/openvpn/client.key"}.
26665 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
26666 Whether to use the lzo compression algorithm.
26668 Defaults to @samp{#t}.
26672 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
26673 Don't re-read key files across SIGUSR1 or --ping-restart.
26675 Defaults to @samp{#t}.
26679 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
26680 Don't close and reopen TUN/TAP device or run up/down scripts across
26681 SIGUSR1 or --ping-restart restarts.
26683 Defaults to @samp{#t}.
26687 @deftypevr {@code{openvpn-client-configuration} parameter} boolean fast-io?
26688 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
26689 poll/epoll/select prior to the write operation.
26691 Defaults to @samp{#f}.
26694 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
26697 Defaults to @samp{3}.
26701 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
26702 Add an additional layer of HMAC authentication on top of the TLS control
26703 channel to protect against DoS attacks.
26705 Defaults to @samp{#f}.
26709 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string auth-user-pass
26710 Authenticate with server using username/password. The option is a file
26711 containing username/password on 2 lines. Do not use a file-like object as it
26712 would be added to the store and readable by any user.
26714 Defaults to @samp{'disabled}.
26717 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
26718 Whether to check the server certificate has server usage extension.
26720 Defaults to @samp{#t}.
26724 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
26725 Bind to a specific local port number.
26727 Defaults to @samp{#f}.
26731 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
26732 Retry resolving server address.
26734 Defaults to @samp{#t}.
26738 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
26739 A list of remote servers to connect to.
26741 Defaults to @samp{()}.
26743 Available @code{openvpn-remote-configuration} fields are:
26745 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
26748 Defaults to @samp{"my-server"}.
26752 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
26753 Port number the server listens to.
26755 Defaults to @samp{1194}.
26760 @c %end of automatic openvpn-client documentation
26762 @c %automatically generated documentation
26764 Available @code{openvpn-server-configuration} fields are:
26766 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
26767 The OpenVPN package.
26771 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
26772 The OpenVPN pid file.
26774 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
26778 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
26779 The protocol (UDP or TCP) used to open a channel between clients and
26782 Defaults to @samp{udp}.
26786 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
26787 The device type used to represent the VPN connection.
26789 Defaults to @samp{tun}.
26793 If you do not have some of these files (eg.@: you use a username and
26794 password), you can disable any of the following three fields by setting
26795 it to @code{'disabled}.
26797 @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string ca
26798 The certificate authority to check connections against.
26800 Defaults to @samp{"/etc/openvpn/ca.crt"}.
26804 @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string cert
26805 The certificate of the machine the daemon is running on. It should be
26806 signed by the authority given in @code{ca}.
26808 Defaults to @samp{"/etc/openvpn/client.crt"}.
26812 @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string key
26813 The key of the machine the daemon is running on. It must be the key whose
26814 certificate is @code{cert}.
26816 Defaults to @samp{"/etc/openvpn/client.key"}.
26820 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
26821 Whether to use the lzo compression algorithm.
26823 Defaults to @samp{#t}.
26827 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
26828 Don't re-read key files across SIGUSR1 or --ping-restart.
26830 Defaults to @samp{#t}.
26834 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
26835 Don't close and reopen TUN/TAP device or run up/down scripts across
26836 SIGUSR1 or --ping-restart restarts.
26838 Defaults to @samp{#t}.
26842 @deftypevr {@code{openvpn-server-configuration} parameter} boolean fast-io?
26843 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
26844 poll/epoll/select prior to the write operation.
26846 Defaults to @samp{#f}.
26849 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
26852 Defaults to @samp{3}.
26856 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
26857 Add an additional layer of HMAC authentication on top of the TLS control
26858 channel to protect against DoS attacks.
26860 Defaults to @samp{#f}.
26864 @deftypevr {@code{openvpn-server-configuration} parameter} number port
26865 Specifies the port number on which the server listens.
26867 Defaults to @samp{1194}.
26871 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
26872 An ip and mask specifying the subnet inside the virtual network.
26874 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
26878 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
26879 A CIDR notation specifying the IPv6 subnet inside the virtual network.
26881 Defaults to @samp{#f}.
26885 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
26886 The Diffie-Hellman parameters file.
26888 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
26892 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
26893 The file that records client IPs.
26895 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
26899 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
26900 When true, the server will act as a gateway for its clients.
26902 Defaults to @samp{#f}.
26906 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
26907 When true, clients are allowed to talk to each other inside the VPN.
26909 Defaults to @samp{#f}.
26913 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
26914 Causes ping-like messages to be sent back and forth over the link so
26915 that each side knows when the other side has gone down. @code{keepalive}
26916 requires a pair. The first element is the period of the ping sending,
26917 and the second element is the timeout before considering the other side
26922 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
26923 The maximum number of clients.
26925 Defaults to @samp{100}.
26929 @deftypevr {@code{openvpn-server-configuration} parameter} string status
26930 The status file. This file shows a small report on current connection.
26931 It is truncated and rewritten every minute.
26933 Defaults to @samp{"/var/run/openvpn/status"}.
26937 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
26938 The list of configuration for some clients.
26940 Defaults to @samp{()}.
26942 Available @code{openvpn-ccd-configuration} fields are:
26944 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
26947 Defaults to @samp{"client"}.
26951 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
26954 Defaults to @samp{#f}.
26958 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
26961 Defaults to @samp{#f}.
26968 @c %end of automatic openvpn-server documentation
26970 @subsubheading Wireguard
26972 @defvr {Scheme Variable} wireguard-service-type
26973 A service type for a Wireguard tunnel interface. Its value must be a
26974 @code{wireguard-configuration} record as in this example:
26977 (service wireguard-service-type
26978 (wireguard-configuration
26983 (endpoint "my.wireguard.com:51820")
26984 (public-key "hzpKg9X1yqu1axN6iJp0mWf6BZGo8m1wteKwtTmDGF4=")
26985 (allowed-ips '("10.0.0.2/32")))))))
26990 @deftp {Data Type} wireguard-configuration
26991 Data type representing the configuration of the Wireguard service.
26994 @item @code{wireguard}
26995 The wireguard package to use for this service.
26997 @item @code{interface} (default: @code{"wg0"})
26998 The interface name for the VPN.
27000 @item @code{addresses} (default: @code{'("10.0.0.1/32")})
27001 The IP addresses to be assigned to the above interface.
27003 @item @code{private-key} (default: @code{"/etc/wireguard/private.key"})
27004 The private key file for the interface. It is automatically generated if
27005 the file does not exist.
27007 @item @code{peers} (default: @code{'()})
27008 The authorized peers on this interface. This is a list of
27009 @var{wireguard-peer} records.
27014 @deftp {Data Type} wireguard-peer
27015 Data type representing a Wireguard peer attached to a given interface.
27021 @item @code{endpoint} (default: @code{#f})
27022 The optional endpoint for the peer, such as
27023 @code{"demo.wireguard.com:51820"}.
27025 @item @code{public-key}
27026 The peer public-key represented as a base64 string.
27028 @item @code{allowed-ips}
27029 A list of IP addresses from which incoming traffic for this peer is
27030 allowed and to which incoming traffic for this peer is directed.
27035 @node Network File System
27036 @subsection Network File System
27039 The @code{(gnu services nfs)} module provides the following services,
27040 which are most commonly used in relation to mounting or exporting
27041 directory trees as @dfn{network file systems} (NFS).
27043 While it is possible to use the individual components that together make
27044 up a Network File System service, we recommended to configure an NFS
27045 server with the @code{nfs-service-type}.
27047 @subsubheading NFS Service
27048 @cindex NFS, server
27050 The NFS service takes care of setting up all NFS component services,
27051 kernel configuration file systems, and installs configuration files in
27052 the locations that NFS expects.
27054 @defvr {Scheme Variable} nfs-service-type
27055 A service type for a complete NFS server.
27058 @deftp {Data Type} nfs-configuration
27059 This data type represents the configuration of the NFS service and all
27062 It has the following parameters:
27064 @item @code{nfs-utils} (default: @code{nfs-utils})
27065 The nfs-utils package to use.
27067 @item @code{nfs-versions} (default: @code{'("4.2" "4.1" "4.0")})
27068 If a list of string values is provided, the @command{rpc.nfsd} daemon
27069 will be limited to supporting the given versions of the NFS protocol.
27071 @item @code{exports} (default: @code{'()})
27072 This is a list of directories the NFS server should export. Each entry
27073 is a list consisting of two elements: a directory name and a string
27074 containing all options. This is an example in which the directory
27075 @file{/export} is served to all NFS clients as a read-only share:
27081 "*(ro,insecure,no_subtree_check,crossmnt,fsid=0)"))))
27084 @item @code{rpcmountd-port} (default: @code{#f})
27085 The network port that the @command{rpc.mountd} daemon should use.
27087 @item @code{rpcstatd-port} (default: @code{#f})
27088 The network port that the @command{rpc.statd} daemon should use.
27090 @item @code{rpcbind} (default: @code{rpcbind})
27091 The rpcbind package to use.
27093 @item @code{idmap-domain} (default: @code{"localdomain"})
27094 The local NFSv4 domain name.
27096 @item @code{nfsd-port} (default: @code{2049})
27097 The network port that the @command{nfsd} daemon should use.
27099 @item @code{nfsd-threads} (default: @code{8})
27100 The number of threads used by the @command{nfsd} daemon.
27102 @item @code{nfsd-tcp?} (default: @code{#t})
27103 Whether the @command{nfsd} daemon should listen on a TCP socket.
27105 @item @code{nfsd-udp?} (default: @code{#f})
27106 Whether the @command{nfsd} daemon should listen on a UDP socket.
27108 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
27109 The directory where the pipefs file system is mounted.
27111 @item @code{debug} (default: @code{'()"})
27112 A list of subsystems for which debugging output should be enabled. This
27113 is a list of symbols. Any of these symbols are valid: @code{nfsd},
27114 @code{nfs}, @code{rpc}, @code{idmap}, @code{statd}, or @code{mountd}.
27118 If you don't need a complete NFS service or prefer to build it yourself
27119 you can use the individual component services that are documented below.
27121 @subsubheading RPC Bind Service
27124 The RPC Bind service provides a facility to map program numbers into
27125 universal addresses.
27126 Many NFS related services use this facility. Hence it is automatically
27127 started when a dependent service starts.
27129 @defvr {Scheme Variable} rpcbind-service-type
27130 A service type for the RPC portmapper daemon.
27134 @deftp {Data Type} rpcbind-configuration
27135 Data type representing the configuration of the RPC Bind Service.
27136 This type has the following parameters:
27138 @item @code{rpcbind} (default: @code{rpcbind})
27139 The rpcbind package to use.
27141 @item @code{warm-start?} (default: @code{#t})
27142 If this parameter is @code{#t}, then the daemon will read a
27143 state file on startup thus reloading state information saved by a previous
27149 @subsubheading Pipefs Pseudo File System
27153 The pipefs file system is used to transfer NFS related data
27154 between the kernel and user space programs.
27156 @defvr {Scheme Variable} pipefs-service-type
27157 A service type for the pipefs pseudo file system.
27160 @deftp {Data Type} pipefs-configuration
27161 Data type representing the configuration of the pipefs pseudo file system service.
27162 This type has the following parameters:
27164 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
27165 The directory to which the file system is to be attached.
27170 @subsubheading GSS Daemon Service
27173 @cindex global security system
27175 The @dfn{global security system} (GSS) daemon provides strong security for RPC
27177 Before exchanging RPC requests an RPC client must establish a security
27178 context. Typically this is done using the Kerberos command @command{kinit}
27179 or automatically at login time using PAM services (@pxref{Kerberos Services}).
27181 @defvr {Scheme Variable} gss-service-type
27182 A service type for the Global Security System (GSS) daemon.
27185 @deftp {Data Type} gss-configuration
27186 Data type representing the configuration of the GSS daemon service.
27187 This type has the following parameters:
27189 @item @code{nfs-utils} (default: @code{nfs-utils})
27190 The package in which the @command{rpc.gssd} command is to be found.
27192 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
27193 The directory where the pipefs file system is mounted.
27199 @subsubheading IDMAP Daemon Service
27201 @cindex name mapper
27203 The idmap daemon service provides mapping between user IDs and user names.
27204 Typically it is required in order to access file systems mounted via NFSv4.
27206 @defvr {Scheme Variable} idmap-service-type
27207 A service type for the Identity Mapper (IDMAP) daemon.
27210 @deftp {Data Type} idmap-configuration
27211 Data type representing the configuration of the IDMAP daemon service.
27212 This type has the following parameters:
27214 @item @code{nfs-utils} (default: @code{nfs-utils})
27215 The package in which the @command{rpc.idmapd} command is to be found.
27217 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
27218 The directory where the pipefs file system is mounted.
27220 @item @code{domain} (default: @code{#f})
27221 The local NFSv4 domain name.
27222 This must be a string or @code{#f}.
27223 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
27225 @item @code{verbosity} (default: @code{0})
27226 The verbosity level of the daemon.
27231 @node Continuous Integration
27232 @subsection Continuous Integration
27234 @cindex continuous integration
27235 @uref{https://guix.gnu.org/cuirass/, Cuirass} is a continuous
27236 integration tool for Guix. It can be used both for development and for
27237 providing substitutes to others (@pxref{Substitutes}).
27239 The @code{(gnu services cuirass)} module provides the following service.
27241 @defvr {Scheme Procedure} cuirass-service-type
27242 The type of the Cuirass service. Its value must be a
27243 @code{cuirass-configuration} object, as described below.
27246 To add build jobs, you have to set the @code{specifications} field of
27247 the configuration. For instance, the following example will build all
27248 the packages provided by the @code{my-channel} channel.
27251 (define %cuirass-specs
27252 #~(list (specification
27253 (name "my-channel")
27254 (build '(channels my-channel))
27258 (url "https://my-channel.git"))
27259 %default-channels)))))
27261 (service cuirass-service-type
27262 (cuirass-configuration
27263 (specifications %cuirass-specs)))
27266 To build the @code{linux-libre} package defined by the default Guix
27267 channel, one can use the following configuration.
27270 (define %cuirass-specs
27271 #~(list (specification
27273 (build '(packages "linux-libre")))))
27275 (service cuirass-service-type
27276 (cuirass-configuration
27277 (specifications %cuirass-specs)))
27280 The other configuration possibilities, as well as the specification
27281 record itself are described in the Cuirass manual
27282 (@pxref{Specifications,,, cuirass, Cuirass}).
27284 While information related to build jobs is located directly in the
27285 specifications, global settings for the @command{cuirass} process are
27286 accessible in other @code{cuirass-configuration} fields.
27288 @deftp {Data Type} cuirass-configuration
27289 Data type representing the configuration of Cuirass.
27292 @item @code{cuirass} (default: @code{cuirass})
27293 The Cuirass package to use.
27295 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
27296 Location of the log file.
27298 @item @code{web-log-file} (default: @code{"/var/log/cuirass-web.log"})
27299 Location of the log file used by the web interface.
27301 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
27302 Location of the repository cache.
27304 @item @code{user} (default: @code{"cuirass"})
27305 Owner of the @code{cuirass} process.
27307 @item @code{group} (default: @code{"cuirass"})
27308 Owner's group of the @code{cuirass} process.
27310 @item @code{interval} (default: @code{60})
27311 Number of seconds between the poll of the repositories followed by the
27314 @item @code{parameters} (default: @code{#f})
27315 Read parameters from the given @var{parameters} file. The supported
27316 parameters are described here (@pxref{Parameters,,, cuirass, Cuirass}).
27318 @item @code{remote-server} (default: @code{#f})
27319 A @code{cuirass-remote-server-configuration} record to use the build
27320 remote mechanism or @code{#f} to use the default build mechanism.
27322 @item @code{database} (default: @code{"dbname=cuirass host=/var/run/postgresql"})
27323 Use @var{database} as the database containing the jobs and the past
27324 build results. Since Cuirass uses PostgreSQL as a database engine,
27325 @var{database} must be a string such as @code{"dbname=cuirass
27328 @item @code{port} (default: @code{8081})
27329 Port number used by the HTTP server.
27331 @item @code{host} (default: @code{"localhost"})
27332 Listen on the network interface for @var{host}. The default is to
27333 accept connections from localhost.
27335 @item @code{specifications} (default: @code{#~'()})
27336 A gexp (@pxref{G-Expressions}) that evaluates to a list of
27337 specifications records. The specification record is described in the
27338 Cuirass manual (@pxref{Specifications,,, cuirass, Cuirass}).
27340 @item @code{use-substitutes?} (default: @code{#f})
27341 This allows using substitutes to avoid building every dependencies of a job
27344 @item @code{one-shot?} (default: @code{#f})
27345 Only evaluate specifications and build derivations once.
27347 @item @code{fallback?} (default: @code{#f})
27348 When substituting a pre-built binary fails, fall back to building
27351 @item @code{extra-options} (default: @code{'()})
27352 Extra options to pass when running the Cuirass processes.
27357 @cindex remote build
27358 @subsubheading Cuirass remote building
27360 Cuirass supports two mechanisms to build derivations.
27363 @item Using the local Guix daemon.
27364 This is the default build mechanism. Once the build jobs are
27365 evaluated, they are sent to the local Guix daemon. Cuirass then
27366 listens to the Guix daemon output to detect the various build events.
27368 @item Using the remote build mechanism.
27369 The build jobs are not submitted to the local Guix daemon. Instead, a
27370 remote server dispatches build requests to the connect remote workers,
27371 according to the build priorities.
27375 To enable this build mode a @code{cuirass-remote-server-configuration}
27376 record must be passed as @code{remote-server} argument of the
27377 @code{cuirass-configuration} record. The
27378 @code{cuirass-remote-server-configuration} record is described below.
27380 This build mode scales way better than the default build mode. This is
27381 the build mode that is used on the GNU Guix build farm at
27382 @url{https://ci.guix.gnu.org}. It should be preferred when using
27383 Cuirass to build large amount of packages.
27385 @deftp {Data Type} cuirass-remote-server-configuration
27386 Data type representing the configuration of the Cuirass remote-server.
27389 @item @code{backend-port} (default: @code{5555})
27390 The TCP port for communicating with @code{remote-worker} processes
27391 using ZMQ. It defaults to @code{5555}.
27393 @item @code{log-port} (default: @code{5556})
27394 The TCP port of the log server. It defaults to @code{5556}.
27396 @item @code{publish-port} (default: @code{5557})
27397 The TCP port of the publish server. It defaults to @code{5557}.
27399 @item @code{log-file} (default: @code{"/var/log/cuirass-remote-server.log"})
27400 Location of the log file.
27402 @item @code{cache} (default: @code{"/var/cache/cuirass/remote"})
27403 Use @var{cache} directory to cache build log files.
27405 @item @code{trigger-url} (default: @code{#f})
27406 Once a substitute is successfully fetched, trigger substitute baking at
27409 @item @code{public-key}
27410 @item @code{private-key}
27411 Use the specific @var{file}s as the public/private key pair used to sign
27412 the store items being published.
27417 At least one remote worker must also be started on any machine of the
27418 local network to actually perform the builds and report their status.
27420 @deftp {Data Type} cuirass-remote-worker-configuration
27421 Data type representing the configuration of the Cuirass remote-worker.
27424 @item @code{cuirass} (default: @code{cuirass})
27425 The Cuirass package to use.
27427 @item @code{workers} (default: @code{1})
27428 Start @var{workers} parallel workers.
27430 @item @code{server} (default: @code{#f})
27431 Do not use Avahi discovery and connect to the given @code{server} IP
27434 @item @code{systems} (default: @code{(list (%current-system))})
27435 Only request builds for the given @var{systems}.
27437 @item @code{log-file} (default: @code{"/var/log/cuirass-remote-worker.log"})
27438 Location of the log file.
27440 @item @code{publish-port} (default: @code{5558})
27441 The TCP port of the publish server. It defaults to @code{5558}.
27443 @item @code{public-key}
27444 @item @code{private-key}
27445 Use the specific @var{file}s as the public/private key pair used to sign
27446 the store items being published.
27451 @subsubheading Laminar
27453 @uref{https://laminar.ohwg.net/, Laminar} is a lightweight and modular
27454 Continuous Integration service. It doesn't have a configuration web UI
27455 instead uses version-controllable configuration files and scripts.
27457 Laminar encourages the use of existing tools such as bash and cron
27458 instead of reinventing them.
27460 @defvr {Scheme Procedure} laminar-service-type
27461 The type of the Laminar service. Its value must be a
27462 @code{laminar-configuration} object, as described below.
27464 All configuration values have defaults, a minimal configuration to get
27465 Laminar running is shown below. By default, the web interface is
27466 available on port 8080.
27469 (service laminar-service-type)
27473 @deftp {Data Type} laminar-configuration
27474 Data type representing the configuration of Laminar.
27477 @item @code{laminar} (default: @code{laminar})
27478 The Laminar package to use.
27480 @item @code{home-directory} (default: @code{"/var/lib/laminar"})
27481 The directory for job configurations and run directories.
27483 @item @code{bind-http} (default: @code{"*:8080"})
27484 The interface/port or unix socket on which laminard should listen for
27485 incoming connections to the web frontend.
27487 @item @code{bind-rpc} (default: @code{"unix-abstract:laminar"})
27488 The interface/port or unix socket on which laminard should listen for
27489 incoming commands such as build triggers.
27491 @item @code{title} (default: @code{"Laminar"})
27492 The page title to show in the web frontend.
27494 @item @code{keep-rundirs} (default: @code{0})
27495 Set to an integer defining how many rundirs to keep per job. The
27496 lowest-numbered ones will be deleted. The default is 0, meaning all run
27497 dirs will be immediately deleted.
27499 @item @code{archive-url} (default: @code{#f})
27500 The web frontend served by laminard will use this URL to form links to
27501 artefacts archived jobs.
27503 @item @code{base-url} (default: @code{#f})
27504 Base URL to use for links to laminar itself.
27509 @node Power Management Services
27510 @subsection Power Management Services
27513 @cindex power management with TLP
27514 @subsubheading TLP daemon
27516 The @code{(gnu services pm)} module provides a Guix service definition
27517 for the Linux power management tool TLP.
27519 TLP enables various powersaving modes in userspace and kernel.
27520 Contrary to @code{upower-service}, it is not a passive,
27521 monitoring tool, as it will apply custom settings each time a new power
27522 source is detected. More information can be found at
27523 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
27525 @deffn {Scheme Variable} tlp-service-type
27526 The service type for the TLP tool. The default settings are optimised
27527 for battery life on most systems, but you can tweak them to your heart's
27528 content by adding a valid @code{tlp-configuration}:
27530 (service tlp-service-type
27532 (cpu-scaling-governor-on-ac (list "performance"))
27533 (sched-powersave-on-bat? #t)))
27537 Each parameter definition is preceded by its type; for example,
27538 @samp{boolean foo} indicates that the @code{foo} parameter
27539 should be specified as a boolean. Types starting with
27540 @code{maybe-} denote parameters that won't show up in TLP config file
27541 when their value is @code{'disabled}.
27543 @c The following documentation was initially generated by
27544 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
27545 @c documentation is better, so we shouldn't hesitate to edit below as
27546 @c needed. However if the change you want to make to this documentation
27547 @c can be done in an automated way, it's probably easier to change
27548 @c (generate-documentation) than to make it below and have to deal with
27549 @c the churn as TLP updates.
27551 Available @code{tlp-configuration} fields are:
27553 @deftypevr {@code{tlp-configuration} parameter} package tlp
27558 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
27559 Set to true if you wish to enable TLP.
27561 Defaults to @samp{#t}.
27565 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
27566 Default mode when no power supply can be detected. Alternatives are AC
27569 Defaults to @samp{"AC"}.
27573 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
27574 Number of seconds Linux kernel has to wait after the disk goes idle,
27575 before syncing on AC.
27577 Defaults to @samp{0}.
27581 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
27582 Same as @code{disk-idle-ac} but on BAT mode.
27584 Defaults to @samp{2}.
27588 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
27589 Dirty pages flushing periodicity, expressed in seconds.
27591 Defaults to @samp{15}.
27595 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
27596 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
27598 Defaults to @samp{60}.
27602 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
27603 CPU frequency scaling governor on AC mode. With intel_pstate driver,
27604 alternatives are powersave and performance. With acpi-cpufreq driver,
27605 alternatives are ondemand, powersave, performance and conservative.
27607 Defaults to @samp{disabled}.
27611 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
27612 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
27614 Defaults to @samp{disabled}.
27618 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
27619 Set the min available frequency for the scaling governor on AC.
27621 Defaults to @samp{disabled}.
27625 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
27626 Set the max available frequency for the scaling governor on AC.
27628 Defaults to @samp{disabled}.
27632 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
27633 Set the min available frequency for the scaling governor on BAT.
27635 Defaults to @samp{disabled}.
27639 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
27640 Set the max available frequency for the scaling governor on BAT.
27642 Defaults to @samp{disabled}.
27646 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
27647 Limit the min P-state to control the power dissipation of the CPU, in AC
27648 mode. Values are stated as a percentage of the available performance.
27650 Defaults to @samp{disabled}.
27654 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
27655 Limit the max P-state to control the power dissipation of the CPU, in AC
27656 mode. Values are stated as a percentage of the available performance.
27658 Defaults to @samp{disabled}.
27662 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
27663 Same as @code{cpu-min-perf-on-ac} on BAT mode.
27665 Defaults to @samp{disabled}.
27669 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
27670 Same as @code{cpu-max-perf-on-ac} on BAT mode.
27672 Defaults to @samp{disabled}.
27676 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
27677 Enable CPU turbo boost feature on AC mode.
27679 Defaults to @samp{disabled}.
27683 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
27684 Same as @code{cpu-boost-on-ac?} on BAT mode.
27686 Defaults to @samp{disabled}.
27690 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
27691 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
27692 used under light load conditions.
27694 Defaults to @samp{#f}.
27698 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
27699 Same as @code{sched-powersave-on-ac?} but on BAT mode.
27701 Defaults to @samp{#t}.
27705 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
27706 Enable Linux kernel NMI watchdog.
27708 Defaults to @samp{#f}.
27712 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
27713 For Linux kernels with PHC patch applied, change CPU voltages. An
27714 example value would be @samp{"F:V F:V F:V F:V"}.
27716 Defaults to @samp{disabled}.
27720 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
27721 Set CPU performance versus energy saving policy on AC@. Alternatives are
27722 performance, normal, powersave.
27724 Defaults to @samp{"performance"}.
27728 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
27729 Same as @code{energy-perf-policy-ac} but on BAT mode.
27731 Defaults to @samp{"powersave"}.
27735 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
27740 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
27741 Hard disk advanced power management level.
27745 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
27746 Same as @code{disk-apm-bat} but on BAT mode.
27750 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
27751 Hard disk spin down timeout. One value has to be specified for each
27752 declared hard disk.
27754 Defaults to @samp{disabled}.
27758 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
27759 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
27761 Defaults to @samp{disabled}.
27765 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
27766 Select IO scheduler for disk devices. One value has to be specified for
27767 each declared hard disk. Example alternatives are cfq, deadline and
27770 Defaults to @samp{disabled}.
27774 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
27775 SATA aggressive link power management (ALPM) level. Alternatives are
27776 min_power, medium_power, max_performance.
27778 Defaults to @samp{"max_performance"}.
27782 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
27783 Same as @code{sata-linkpwr-ac} but on BAT mode.
27785 Defaults to @samp{"min_power"}.
27789 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
27790 Exclude specified SATA host devices for link power management.
27792 Defaults to @samp{disabled}.
27796 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
27797 Enable Runtime Power Management for AHCI controller and disks on AC
27800 Defaults to @samp{disabled}.
27804 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
27805 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
27807 Defaults to @samp{disabled}.
27811 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
27812 Seconds of inactivity before disk is suspended.
27814 Defaults to @samp{15}.
27818 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
27819 PCI Express Active State Power Management level. Alternatives are
27820 default, performance, powersave.
27822 Defaults to @samp{"performance"}.
27826 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
27827 Same as @code{pcie-aspm-ac} but on BAT mode.
27829 Defaults to @samp{"powersave"}.
27833 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
27834 Radeon graphics clock speed level. Alternatives are low, mid, high,
27837 Defaults to @samp{"high"}.
27841 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
27842 Same as @code{radeon-power-ac} but on BAT mode.
27844 Defaults to @samp{"low"}.
27848 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
27849 Radeon dynamic power management method (DPM). Alternatives are battery,
27852 Defaults to @samp{"performance"}.
27856 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
27857 Same as @code{radeon-dpm-state-ac} but on BAT mode.
27859 Defaults to @samp{"battery"}.
27863 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
27864 Radeon DPM performance level. Alternatives are auto, low, high.
27866 Defaults to @samp{"auto"}.
27870 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
27871 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
27873 Defaults to @samp{"auto"}.
27877 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
27878 Wifi power saving mode.
27880 Defaults to @samp{#f}.
27884 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
27885 Same as @code{wifi-power-ac?} but on BAT mode.
27887 Defaults to @samp{#t}.
27891 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
27892 Disable wake on LAN.
27894 Defaults to @samp{#t}.
27898 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
27899 Timeout duration in seconds before activating audio power saving on
27900 Intel HDA and AC97 devices. A value of 0 disables power saving.
27902 Defaults to @samp{0}.
27906 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
27907 Same as @code{sound-powersave-ac} but on BAT mode.
27909 Defaults to @samp{1}.
27913 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
27914 Disable controller in powersaving mode on Intel HDA devices.
27916 Defaults to @samp{#t}.
27920 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
27921 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
27922 powered on again by releasing (and reinserting) the eject lever or by
27923 pressing the disc eject button on newer models.
27925 Defaults to @samp{#f}.
27929 @deftypevr {@code{tlp-configuration} parameter} string bay-device
27930 Name of the optical drive device to power off.
27932 Defaults to @samp{"sr0"}.
27936 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
27937 Runtime Power Management for PCI(e) bus devices. Alternatives are on
27940 Defaults to @samp{"on"}.
27944 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
27945 Same as @code{runtime-pm-ac} but on BAT mode.
27947 Defaults to @samp{"auto"}.
27951 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
27952 Runtime Power Management for all PCI(e) bus devices, except blacklisted
27955 Defaults to @samp{#t}.
27959 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
27960 Exclude specified PCI(e) device addresses from Runtime Power Management.
27962 Defaults to @samp{disabled}.
27966 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
27967 Exclude PCI(e) devices assigned to the specified drivers from Runtime
27972 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
27973 Enable USB autosuspend feature.
27975 Defaults to @samp{#t}.
27979 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
27980 Exclude specified devices from USB autosuspend.
27982 Defaults to @samp{disabled}.
27986 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
27987 Exclude WWAN devices from USB autosuspend.
27989 Defaults to @samp{#t}.
27993 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
27994 Include specified devices into USB autosuspend, even if they are already
27995 excluded by the driver or via @code{usb-blacklist-wwan?}.
27997 Defaults to @samp{disabled}.
28001 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
28002 Enable USB autosuspend before shutdown.
28004 Defaults to @samp{disabled}.
28008 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
28009 Restore radio device state (bluetooth, wifi, wwan) from previous
28010 shutdown on system startup.
28012 Defaults to @samp{#f}.
28017 @cindex CPU frequency scaling with thermald
28018 @subsubheading Thermald daemon
28020 The @code{(gnu services pm)} module provides an interface to
28021 thermald, a CPU frequency scaling service which helps prevent overheating.
28023 @defvr {Scheme Variable} thermald-service-type
28024 This is the service type for
28025 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
28026 Thermal Daemon, which is responsible for controlling the thermal state
28027 of processors and preventing overheating.
28030 @deftp {Data Type} thermald-configuration
28031 Data type representing the configuration of @code{thermald-service-type}.
28034 @item @code{ignore-cpuid-check?} (default: @code{#f})
28035 Ignore cpuid check for supported CPU models.
28037 @item @code{thermald} (default: @var{thermald})
28038 Package object of thermald.
28043 @node Audio Services
28044 @subsection Audio Services
28046 The @code{(gnu services audio)} module provides a service to start MPD
28047 (the Music Player Daemon).
28050 @subsubheading Music Player Daemon
28052 The Music Player Daemon (MPD) is a service that can play music while
28053 being controlled from the local machine or over the network by a variety
28056 The following example shows how one might run @code{mpd} as user
28057 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
28060 (service mpd-service-type
28066 @defvr {Scheme Variable} mpd-service-type
28067 The service type for @command{mpd}
28070 @deftp {Data Type} mpd-configuration
28071 Data type representing the configuration of @command{mpd}.
28074 @item @code{user} (default: @code{"mpd"})
28075 The user to run mpd as.
28077 @item @code{music-dir} (default: @code{"~/Music"})
28078 The directory to scan for music files.
28080 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
28081 The directory to store playlists.
28083 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
28084 The location of the music database.
28086 @item @code{state-file} (default: @code{"~/.mpd/state"})
28087 The location of the file that stores current MPD's state.
28089 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
28090 The location of the sticker database.
28092 @item @code{port} (default: @code{"6600"})
28093 The port to run mpd on.
28095 @item @code{address} (default: @code{"any"})
28096 The address that mpd will bind to. To use a Unix domain socket,
28097 an absolute path can be specified here.
28099 @item @code{outputs} (default: @code{"(list (mpd-output))"})
28100 The audio outputs that MPD can use. By default this is a single output using pulseaudio.
28105 @deftp {Data Type} mpd-output
28106 Data type representing an @command{mpd} audio output.
28109 @item @code{name} (default: @code{"MPD"})
28110 The name of the audio output.
28112 @item @code{type} (default: @code{"pulse"})
28113 The type of audio output.
28115 @item @code{enabled?} (default: @code{#t})
28116 Specifies whether this audio output is enabled when MPD is started. By
28117 default, all audio outputs are enabled. This is just the default
28118 setting when there is no state file; with a state file, the previous
28121 @item @code{tags?} (default: @code{#t})
28122 If set to @code{#f}, then MPD will not send tags to this output. This
28123 is only useful for output plugins that can receive tags, for example the
28124 @code{httpd} output plugin.
28126 @item @code{always-on?} (default: @code{#f})
28127 If set to @code{#t}, then MPD attempts to keep this audio output always
28128 open. This may be useful for streaming servers, when you don’t want to
28129 disconnect all listeners even when playback is accidentally stopped.
28131 @item @code{mixer-type}
28132 This field accepts a symbol that specifies which mixer should be used
28133 for this audio output: the @code{hardware} mixer, the @code{software}
28134 mixer, the @code{null} mixer (allows setting the volume, but with no
28135 effect; this can be used as a trick to implement an external mixer
28136 External Mixer) or no mixer (@code{none}).
28138 @item @code{extra-options} (default: @code{'()})
28139 An association list of option symbols to string values to be appended to
28140 the audio output configuration.
28145 The following example shows a configuration of @code{mpd} that provides
28146 an HTTP audio streaming output.
28149 (service mpd-service-type
28157 `((encoder . "vorbis")
28158 (port . "8080"))))))))
28162 @node Virtualization Services
28163 @subsection Virtualization Services
28165 The @code{(gnu services virtualization)} module provides services for
28166 the libvirt and virtlog daemons, as well as other virtualization-related
28169 @subsubheading Libvirt daemon
28171 @code{libvirtd} is the server side daemon component of the libvirt
28172 virtualization management system. This daemon runs on host servers
28173 and performs required management tasks for virtualized guests.
28175 @deffn {Scheme Variable} libvirt-service-type
28176 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
28177 Its value must be a @code{libvirt-configuration}.
28180 (service libvirt-service-type
28181 (libvirt-configuration
28182 (unix-sock-group "libvirt")
28183 (tls-port "16555")))
28187 @c Auto-generated with (generate-libvirt-documentation)
28188 Available @code{libvirt-configuration} fields are:
28190 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
28195 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
28196 Flag listening for secure TLS connections on the public TCP/IP port.
28197 You must set @code{listen} for this to have any effect.
28199 It is necessary to setup a CA and issue server certificates before using
28202 Defaults to @samp{#t}.
28206 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
28207 Listen for unencrypted TCP connections on the public TCP/IP port. You must
28208 set @code{listen} for this to have any effect.
28210 Using the TCP socket requires SASL authentication by default. Only SASL
28211 mechanisms which support data encryption are allowed. This is
28212 DIGEST_MD5 and GSSAPI (Kerberos5).
28214 Defaults to @samp{#f}.
28218 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
28219 Port for accepting secure TLS connections. This can be a port number,
28222 Defaults to @samp{"16514"}.
28226 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
28227 Port for accepting insecure TCP connections. This can be a port number,
28230 Defaults to @samp{"16509"}.
28234 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
28235 IP address or hostname used for client connections.
28237 Defaults to @samp{"0.0.0.0"}.
28241 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
28242 Flag toggling mDNS advertisement of the libvirt service.
28244 Alternatively can disable for all services on a host by stopping the
28247 Defaults to @samp{#f}.
28251 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
28252 Default mDNS advertisement name. This must be unique on the immediate
28255 Defaults to @samp{"Virtualization Host <hostname>"}.
28259 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
28260 UNIX domain socket group ownership. This can be used to allow a
28261 'trusted' set of users access to management capabilities without
28264 Defaults to @samp{"root"}.
28268 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
28269 UNIX socket permissions for the R/O socket. This is used for monitoring
28272 Defaults to @samp{"0777"}.
28276 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
28277 UNIX socket permissions for the R/W socket. Default allows only root.
28278 If PolicyKit is enabled on the socket, the default will change to allow
28279 everyone (eg, 0777)
28281 Defaults to @samp{"0770"}.
28285 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
28286 UNIX socket permissions for the admin socket. Default allows only owner
28287 (root), do not change it unless you are sure to whom you are exposing
28290 Defaults to @samp{"0777"}.
28294 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
28295 The directory in which sockets will be found/created.
28297 Defaults to @samp{"/var/run/libvirt"}.
28301 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
28302 Authentication scheme for UNIX read-only sockets. By default socket
28303 permissions allow anyone to connect
28305 Defaults to @samp{"polkit"}.
28309 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
28310 Authentication scheme for UNIX read-write sockets. By default socket
28311 permissions only allow root. If PolicyKit support was compiled into
28312 libvirt, the default will be to use 'polkit' auth.
28314 Defaults to @samp{"polkit"}.
28318 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
28319 Authentication scheme for TCP sockets. If you don't enable SASL, then
28320 all TCP traffic is cleartext. Don't do this outside of a dev/test
28323 Defaults to @samp{"sasl"}.
28327 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
28328 Authentication scheme for TLS sockets. TLS sockets already have
28329 encryption provided by the TLS layer, and limited authentication is done
28332 It is possible to make use of any SASL authentication mechanism as well,
28333 by using 'sasl' for this option
28335 Defaults to @samp{"none"}.
28339 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
28340 API access control scheme.
28342 By default an authenticated user is allowed access to all APIs. Access
28343 drivers can place restrictions on this.
28345 Defaults to @samp{()}.
28349 @deftypevr {@code{libvirt-configuration} parameter} string key-file
28350 Server key file path. If set to an empty string, then no private key is
28353 Defaults to @samp{""}.
28357 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
28358 Server key file path. If set to an empty string, then no certificate is
28361 Defaults to @samp{""}.
28365 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
28366 Server key file path. If set to an empty string, then no CA certificate
28369 Defaults to @samp{""}.
28373 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
28374 Certificate revocation list path. If set to an empty string, then no
28377 Defaults to @samp{""}.
28381 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
28382 Disable verification of our own server certificates.
28384 When libvirtd starts it performs some sanity checks against its own
28387 Defaults to @samp{#f}.
28391 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
28392 Disable verification of client certificates.
28394 Client certificate verification is the primary authentication mechanism.
28395 Any client which does not present a certificate signed by the CA will be
28398 Defaults to @samp{#f}.
28402 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
28403 Whitelist of allowed x509 Distinguished Name.
28405 Defaults to @samp{()}.
28409 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
28410 Whitelist of allowed SASL usernames. The format for username depends on
28411 the SASL authentication mechanism.
28413 Defaults to @samp{()}.
28417 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
28418 Override the compile time default TLS priority string. The default is
28419 usually @samp{"NORMAL"} unless overridden at build time. Only set this is it
28420 is desired for libvirt to deviate from the global default settings.
28422 Defaults to @samp{"NORMAL"}.
28426 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
28427 Maximum number of concurrent client connections to allow over all
28430 Defaults to @samp{5000}.
28434 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
28435 Maximum length of queue of connections waiting to be accepted by the
28436 daemon. Note, that some protocols supporting retransmission may obey
28437 this so that a later reattempt at connection succeeds.
28439 Defaults to @samp{1000}.
28443 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
28444 Maximum length of queue of accepted but not yet authenticated clients.
28445 Set this to zero to turn this feature off
28447 Defaults to @samp{20}.
28451 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
28452 Number of workers to start up initially.
28454 Defaults to @samp{5}.
28458 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
28459 Maximum number of worker threads.
28461 If the number of active clients exceeds @code{min-workers}, then more
28462 threads are spawned, up to max_workers limit. Typically you'd want
28463 max_workers to equal maximum number of clients allowed.
28465 Defaults to @samp{20}.
28469 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
28470 Number of priority workers. If all workers from above pool are stuck,
28471 some calls marked as high priority (notably domainDestroy) can be
28472 executed in this pool.
28474 Defaults to @samp{5}.
28478 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
28479 Total global limit on concurrent RPC calls.
28481 Defaults to @samp{20}.
28485 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
28486 Limit on concurrent requests from a single client connection. To avoid
28487 one client monopolizing the server this should be a small fraction of
28488 the global max_requests and max_workers parameter.
28490 Defaults to @samp{5}.
28494 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
28495 Same as @code{min-workers} but for the admin interface.
28497 Defaults to @samp{1}.
28501 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
28502 Same as @code{max-workers} but for the admin interface.
28504 Defaults to @samp{5}.
28508 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
28509 Same as @code{max-clients} but for the admin interface.
28511 Defaults to @samp{5}.
28515 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
28516 Same as @code{max-queued-clients} but for the admin interface.
28518 Defaults to @samp{5}.
28522 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
28523 Same as @code{max-client-requests} but for the admin interface.
28525 Defaults to @samp{5}.
28529 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
28530 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
28532 Defaults to @samp{3}.
28536 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
28539 A filter allows to select a different logging level for a given category
28540 of logs. The format for a filter is one of:
28551 where @code{name} is a string which is matched against the category
28552 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
28553 file, e.g., @samp{"remote"}, @samp{"qemu"}, or @samp{"util.json"} (the
28554 name in the filter can be a substring of the full category name, in
28555 order to match multiple similar categories), the optional @samp{"+"}
28556 prefix tells libvirt to log stack trace for each message matching name,
28557 and @code{x} is the minimal level where matching messages should be
28575 Multiple filters can be defined in a single filters statement, they just
28576 need to be separated by spaces.
28578 Defaults to @samp{"3:remote 4:event"}.
28582 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
28585 An output is one of the places to save logging information. The format
28586 for an output can be:
28590 output goes to stderr
28592 @item x:syslog:name
28593 use syslog for the output and use the given name as the ident
28595 @item x:file:file_path
28596 output to a file, with the given filepath
28599 output to journald logging system
28603 In all case the x prefix is the minimal level, acting as a filter
28620 Multiple outputs can be defined, they just need to be separated by
28623 Defaults to @samp{"3:stderr"}.
28627 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
28628 Allows usage of the auditing subsystem to be altered
28632 0: disable all auditing
28635 1: enable auditing, only if enabled on host
28638 2: enable auditing, and exit if disabled on host.
28642 Defaults to @samp{1}.
28646 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
28647 Send audit messages via libvirt logging infrastructure.
28649 Defaults to @samp{#f}.
28653 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
28654 Host UUID@. UUID must not have all digits be the same.
28656 Defaults to @samp{""}.
28660 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
28661 Source to read host UUID.
28665 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
28668 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
28672 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
28675 Defaults to @samp{"smbios"}.
28679 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
28680 A keepalive message is sent to a client after @code{keepalive_interval}
28681 seconds of inactivity to check if the client is still responding. If
28682 set to -1, libvirtd will never send keepalive requests; however clients
28683 can still send them and the daemon will send responses.
28685 Defaults to @samp{5}.
28689 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
28690 Maximum number of keepalive messages that are allowed to be sent to the
28691 client without getting any response before the connection is considered
28694 In other words, the connection is automatically closed approximately
28695 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
28696 the last message received from the client. When @code{keepalive-count}
28697 is set to 0, connections will be automatically closed after
28698 @code{keepalive-interval} seconds of inactivity without sending any
28699 keepalive messages.
28701 Defaults to @samp{5}.
28705 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
28706 Same as above but for admin interface.
28708 Defaults to @samp{5}.
28712 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
28713 Same as above but for admin interface.
28715 Defaults to @samp{5}.
28719 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
28720 Timeout for Open vSwitch calls.
28722 The @code{ovs-vsctl} utility is used for the configuration and its
28723 timeout option is set by default to 5 seconds to avoid potential
28724 infinite waits blocking libvirt.
28726 Defaults to @samp{5}.
28730 @c %end of autogenerated docs
28732 @subsubheading Virtlog daemon
28733 The virtlogd service is a server side daemon component of libvirt that is
28734 used to manage logs from virtual machine consoles.
28736 This daemon is not used directly by libvirt client applications, rather it
28737 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
28738 standalone daemon, the main @code{libvirtd} daemon can be restarted without
28739 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
28740 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
28742 @deffn {Scheme Variable} virtlog-service-type
28743 This is the type of the virtlog daemon.
28744 Its value must be a @code{virtlog-configuration}.
28747 (service virtlog-service-type
28748 (virtlog-configuration
28749 (max-clients 1000)))
28753 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
28754 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
28756 Defaults to @samp{3}.
28760 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
28763 A filter allows to select a different logging level for a given category
28764 of logs The format for a filter is one of:
28775 where @code{name} is a string which is matched against the category
28776 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
28777 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
28778 be a substring of the full category name, in order to match multiple
28779 similar categories), the optional "+" prefix tells libvirt to log stack
28780 trace for each message matching name, and @code{x} is the minimal level
28781 where matching messages should be logged:
28798 Multiple filters can be defined in a single filters statement, they just
28799 need to be separated by spaces.
28801 Defaults to @samp{"3:remote 4:event"}.
28805 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
28808 An output is one of the places to save logging information The format
28809 for an output can be:
28813 output goes to stderr
28815 @item x:syslog:name
28816 use syslog for the output and use the given name as the ident
28818 @item x:file:file_path
28819 output to a file, with the given filepath
28822 output to journald logging system
28826 In all case the x prefix is the minimal level, acting as a filter
28843 Multiple outputs can be defined, they just need to be separated by
28846 Defaults to @samp{"3:stderr"}.
28850 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
28851 Maximum number of concurrent client connections to allow over all
28854 Defaults to @samp{1024}.
28858 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
28859 Maximum file size before rolling over.
28861 Defaults to @samp{2MB}
28865 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
28866 Maximum number of backup files to keep.
28868 Defaults to @samp{3}
28872 @anchor{transparent-emulation-qemu}
28873 @subsubheading Transparent Emulation with QEMU
28876 @cindex @code{binfmt_misc}
28877 @code{qemu-binfmt-service-type} provides support for transparent
28878 emulation of program binaries built for different architectures---e.g.,
28879 it allows you to transparently execute an ARMv7 program on an x86_64
28880 machine. It achieves this by combining the @uref{https://www.qemu.org,
28881 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
28882 This feature only allows you to emulate GNU/Linux on a different
28883 architecture, but see below for GNU/Hurd support.
28885 @defvr {Scheme Variable} qemu-binfmt-service-type
28886 This is the type of the QEMU/binfmt service for transparent emulation.
28887 Its value must be a @code{qemu-binfmt-configuration} object, which
28888 specifies the QEMU package to use as well as the architecture we want to
28892 (service qemu-binfmt-service-type
28893 (qemu-binfmt-configuration
28894 (platforms (lookup-qemu-platforms "arm" "aarch64"))))
28897 In this example, we enable transparent emulation for the ARM and aarch64
28898 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
28899 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
28900 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
28903 @deftp {Data Type} qemu-binfmt-configuration
28904 This is the configuration for the @code{qemu-binfmt} service.
28907 @item @code{platforms} (default: @code{'()})
28908 The list of emulated QEMU platforms. Each item must be a @dfn{platform
28909 object} as returned by @code{lookup-qemu-platforms} (see below).
28911 For example, let's suppose you're on an x86_64 machine and you have this
28915 (service qemu-binfmt-service-type
28916 (qemu-binfmt-configuration
28917 (platforms (lookup-qemu-platforms "arm"))))
28923 guix build -s armhf-linux inkscape
28927 and it will build Inkscape for ARMv7 @emph{as if it were a native
28928 build}, transparently using QEMU to emulate the ARMv7 CPU@. Pretty handy
28929 if you'd like to test a package build for an architecture you don't have
28932 @item @code{qemu} (default: @code{qemu})
28933 The QEMU package to use.
28937 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
28938 Return the list of QEMU platform objects corresponding to
28939 @var{platforms}@dots{}. @var{platforms} must be a list of strings
28940 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
28941 @code{"mips64el"}, and so on.
28944 @deffn {Scheme Procedure} qemu-platform? @var{obj}
28945 Return true if @var{obj} is a platform object.
28948 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
28949 Return the name of @var{platform}---a string such as @code{"arm"}.
28953 @subsubheading The Hurd in a Virtual Machine
28955 @cindex @code{hurd}
28959 Service @code{hurd-vm} provides support for running GNU/Hurd in a
28960 virtual machine (VM), a so-called @dfn{childhurd}. This service is meant
28961 to be used on GNU/Linux and the given GNU/Hurd operating system
28962 configuration is cross-compiled. The virtual machine is a Shepherd
28963 service that can be referred to by the names @code{hurd-vm} and
28964 @code{childhurd} and be controlled with commands such as:
28968 herd stop childhurd
28971 When the service is running, you can view its console by connecting to
28972 it with a VNC client, for example with:
28975 guix environment --ad-hoc tigervnc-client -- \
28976 vncviewer localhost:5900
28979 The default configuration (see @code{hurd-vm-configuration} below)
28980 spawns a secure shell (SSH) server in your GNU/Hurd system, which QEMU
28981 (the virtual machine emulator) redirects to port 10222 on the host.
28982 Thus, you can connect over SSH to the childhurd with:
28985 ssh root@@localhost -p 10022
28988 The childhurd is volatile and stateless: it starts with a fresh root
28989 file system every time you restart it. By default though, all the files
28990 under @file{/etc/childhurd} on the host are copied as is to the root
28991 file system of the childhurd when it boots. This allows you to
28992 initialize ``secrets'' inside the VM: SSH host keys, authorized
28993 substitute keys, and so on---see the explanation of @code{secret-root}
28996 @defvr {Scheme Variable} hurd-vm-service-type
28997 This is the type of the Hurd in a Virtual Machine service. Its value
28998 must be a @code{hurd-vm-configuration} object, which specifies the
28999 operating system (@pxref{operating-system Reference}) and the disk size
29000 for the Hurd Virtual Machine, the QEMU package to use as well as the
29001 options for running it.
29006 (service hurd-vm-service-type
29007 (hurd-vm-configuration
29008 (disk-size (* 5000 (expt 2 20))) ;5G
29009 (memory-size 1024))) ;1024MiB
29012 would create a disk image big enough to build GNU@tie{}Hello, with some
29016 @deftp {Data Type} hurd-vm-configuration
29017 The data type representing the configuration for
29018 @code{hurd-vm-service-type}.
29021 @item @code{os} (default: @var{%hurd-vm-operating-system})
29022 The operating system to instantiate. This default is bare-bones with a
29023 permissive OpenSSH secure shell daemon listening on port 2222
29024 (@pxref{Networking Services, @code{openssh-service-type}}).
29026 @item @code{qemu} (default: @code{qemu-minimal})
29027 The QEMU package to use.
29029 @item @code{image} (default: @var{hurd-vm-disk-image})
29030 The procedure used to build the disk-image built from this
29033 @item @code{disk-size} (default: @code{'guess})
29034 The size of the disk image.
29036 @item @code{memory-size} (default: @code{512})
29037 The memory size of the Virtual Machine in mebibytes.
29039 @item @code{options} (default: @code{'("--snapshot")})
29040 The extra options for running QEMU.
29042 @item @code{id} (default: @code{#f})
29043 If set, a non-zero positive integer used to parameterize Childhurd
29044 instances. It is appended to the service's name,
29045 e.g. @code{childhurd1}.
29047 @item @code{net-options} (default: @var{hurd-vm-net-options})
29048 The procedure used to produce the list of QEMU networking options.
29050 By default, it produces
29053 '("--device" "rtl8139,netdev=net0"
29054 "--netdev" "user,id=net0\
29055 ,hostfwd=tcp:127.0.0.1:@var{secrets-port}-:1004\
29056 ,hostfwd=tcp:127.0.0.1:@var{ssh-port}-:2222\
29057 ,hostfwd=tcp:127.0.0.1:@var{vnc-port}-:5900")
29060 with forwarded ports:
29063 @var{secrets-port}: @code{(+ 11004 (* 1000 @var{ID}))}
29064 @var{ssh-port}: @code{(+ 10022 (* 1000 @var{ID}))}
29065 @var{vnc-port}: @code{(+ 15900 (* 1000 @var{ID}))}
29068 @item @code{secret-root} (default: @file{/etc/childhurd})
29069 The root directory with out-of-band secrets to be installed into the
29070 childhurd once it runs. Childhurds are volatile which means that on
29071 every startup, secrets such as the SSH host keys and Guix signing key
29074 If the @file{/etc/childhurd} directory does not exist, the
29075 @code{secret-service} running in the Childhurd will be sent an empty
29078 By default, the service automatically populates @file{/etc/childhurd}
29079 with the following non-volatile secrets, unless they already exist:
29082 /etc/childhurd/etc/guix/acl
29083 /etc/childhurd/etc/guix/signing-key.pub
29084 /etc/childhurd/etc/guix/signing-key.sec
29085 /etc/childhurd/etc/ssh/ssh_host_ed25519_key
29086 /etc/childhurd/etc/ssh/ssh_host_ecdsa_key
29087 /etc/childhurd/etc/ssh/ssh_host_ed25519_key.pub
29088 /etc/childhurd/etc/ssh/ssh_host_ecdsa_key.pub
29091 These files are automatically sent to the guest Hurd VM when it boots,
29092 including permissions.
29094 @cindex childhurd, offloading
29095 @cindex Hurd, offloading
29096 Having these files in place means that only a couple of things are
29097 missing to allow the host to offload @code{i586-gnu} builds to the
29102 Authorizing the childhurd's key on the host so that the host accepts
29103 build results coming from the childhurd, which can be done like so:
29106 guix archive --authorize < \
29107 /etc/childhurd/etc/guix/signing-key.pub
29111 Adding the childhurd to @file{/etc/guix/machines.scm} (@pxref{Daemon
29115 We're working towards making that happen automatically---get in touch
29116 with us at @email{guix-devel@@gnu.org} to discuss it!
29120 Note that by default the VM image is volatile, i.e., once stopped the
29121 contents are lost. If you want a stateful image instead, override the
29122 configuration's @code{image} and @code{options} without
29123 the @code{--snapshot} flag using something along these lines:
29126 (service hurd-vm-service-type
29127 (hurd-vm-configuration
29128 (image (const "/out/of/store/writable/hurd.img"))
29132 @subsubheading Ganeti
29137 This service is considered experimental. Configuration options may be changed
29138 in a backwards-incompatible manner, and not all features have been thorougly
29139 tested. Users of this service are encouraged to share their experience at
29140 @email{guix-devel@@gnu.org}.
29143 Ganeti is a virtual machine management system. It is designed to keep virtual
29144 machines running on a cluster of servers even in the event of hardware failures,
29145 and to make maintenance and recovery tasks easy. It consists of multiple
29146 services which are described later in this section. In addition to the Ganeti
29147 service, you will need the OpenSSH service (@pxref{Networking Services,
29148 @code{openssh-service-type}}), and update the @file{/etc/hosts} file
29149 (@pxref{operating-system Reference, @code{hosts-file}}) with the cluster name
29150 and address (or use a DNS server).
29152 All nodes participating in a Ganeti cluster should have the same Ganeti and
29153 @file{/etc/hosts} configuration. Here is an example configuration for a Ganeti
29154 cluster node that supports multiple storage backends, and installs the
29155 @code{debootstrap} and @code{guix} @dfn{OS providers}:
29158 (use-package-modules virtualization)
29159 (use-service-modules base ganeti networking ssh)
29162 (host-name "node1")
29163 (hosts-file (plain-file "hosts" (format #f "
29164 127.0.0.1 localhost
29167 192.168.1.200 ganeti.example.com
29168 192.168.1.201 node1.example.com node1
29169 192.168.1.202 node2.example.com node2
29172 ;; Install QEMU so we can use KVM-based instances, and LVM, DRBD and Ceph
29173 ;; in order to use the "plain", "drbd" and "rbd" storage backends.
29174 (packages (append (map specification->package
29175 '("qemu" "lvm2" "drbd-utils" "ceph"
29176 ;; Add the debootstrap and guix OS providers.
29177 "ganeti-instance-guix" "ganeti-instance-debootstrap"))
29180 (append (list (static-networking-service "eth0" "192.168.1.201"
29181 #:netmask "255.255.255.0"
29182 #:gateway "192.168.1.254"
29183 #:name-servers '("192.168.1.252"
29186 ;; Ganeti uses SSH to communicate between nodes.
29187 (service openssh-service-type
29188 (openssh-configuration
29189 (permit-root-login 'without-password)))
29191 (service ganeti-service-type
29192 (ganeti-configuration
29193 ;; This list specifies allowed file system paths
29194 ;; for storing virtual machine images.
29195 (file-storage-paths '("/srv/ganeti/file-storage"))
29196 ;; This variable configures a single "variant" for
29197 ;; both Debootstrap and Guix that works with KVM.
29198 (os %default-ganeti-os))))
29202 Users are advised to read the
29203 @url{http://docs.ganeti.org/ganeti/master/html/admin.html,Ganeti
29204 administrators guide} to learn about the various cluster options and
29205 day-to-day operations. There is also a
29206 @url{https://guix.gnu.org/blog/2020/running-a-ganeti-cluster-on-guix/,blog post}
29207 describing how to configure and initialize a small cluster.
29209 @defvr {Scheme Variable} ganeti-service-type
29210 This is a service type that includes all the various services that Ganeti
29213 Its value is a @code{ganeti-configuration} object that defines the package
29214 to use for CLI operations, as well as configuration for the various daemons.
29215 Allowed file storage paths and available guest operating systems are also
29216 configured through this data type.
29219 @deftp {Data Type} ganeti-configuration
29220 The @code{ganeti} service takes the following configuration options:
29223 @item @code{ganeti} (default: @code{ganeti})
29224 The @code{ganeti} package to use. It will be installed to the system profile
29225 and make @command{gnt-cluster}, @command{gnt-instance}, etc available. Note
29226 that the value specified here does not affect the other services as each refer
29227 to a specific @code{ganeti} package (see below).
29229 @item @code{noded-configuration} (default: @code{(ganeti-noded-configuration)})
29230 @itemx @code{confd-configuration} (default: @code{(ganeti-confd-configuration)})
29231 @itemx @code{wconfd-configuration} (default: @code{(ganeti-wconfd-configuration)})
29232 @itemx @code{luxid-configuration} (default: @code{(ganeti-luxid-configuration)})
29233 @itemx @code{rapi-configuration} (default: @code{(ganeti-rapi-configuration)})
29234 @itemx @code{kvmd-configuration} (default: @code{(ganeti-kvmd-configuration)})
29235 @itemx @code{mond-configuration} (default: @code{(ganeti-mond-configuration)})
29236 @itemx @code{metad-configuration} (default: @code{(ganeti-metad-configuration)})
29237 @itemx @code{watcher-configuration} (default: @code{(ganeti-watcher-configuration)})
29238 @itemx @code{cleaner-configuration} (default: @code{(ganeti-cleaner-configuration)})
29240 These options control the various daemons and cron jobs that are distributed
29241 with Ganeti. The possible values for these are described in detail below.
29242 To override a setting, you must use the configuration type for that service:
29245 (service ganeti-service-type
29246 (ganeti-configuration
29247 (rapi-configuration
29248 (ganeti-rapi-configuration
29249 (interface "eth1"))))
29250 (watcher-configuration
29251 (ganeti-watcher-configuration
29252 (rapi-ip "10.0.0.1"))))
29255 @item @code{file-storage-paths} (default: @code{'()})
29256 List of allowed directories for file storage backend.
29258 @item @code{os} (default: @code{%default-ganeti-os})
29259 List of @code{<ganeti-os>} records.
29262 In essence @code{ganeti-service-type} is shorthand for declaring each service
29266 (service ganeti-noded-service-type)
29267 (service ganeti-confd-service-type)
29268 (service ganeti-wconfd-service-type)
29269 (service ganeti-luxid-service-type)
29270 (service ganeti-kvmd-service-type)
29271 (service ganeti-mond-service-type)
29272 (service ganeti-metad-service-type)
29273 (service ganeti-watcher-service-type)
29274 (service ganeti-cleaner-service-type)
29277 Plus a service extension for @code{etc-service-type} that configures the file
29278 storage backend and OS variants.
29282 @deftp {Data Type} ganeti-os
29283 This data type is suitable for passing to the @code{os} parameter of
29284 @code{ganeti-configuration}. It takes the following parameters:
29288 The name for this OS provider. It is only used to specify where the
29289 configuration ends up. Setting it to ``debootstrap'' will create
29290 @file{/etc/ganeti/instance-debootstrap}.
29292 @item @code{extension}
29293 The file extension for variants of this OS type. For example
29294 @file{.conf} or @file{.scm}.
29296 @item @code{variants} (default: @code{'()})
29297 List of @code{ganeti-os-variant} objects for this OS.
29302 @deftp {Data Type} ganeti-os-variant
29303 This is the data type for a Ganeti OS variant. It takes the following
29308 The name of this variant.
29310 @item @code{configuration}
29311 A configuration file for this variant.
29315 @defvr {Scheme Variable} %default-debootstrap-hooks
29316 This variable contains hooks to configure networking and the GRUB bootloader.
29319 @defvr {Scheme Variable} %default-debootstrap-extra-pkgs
29320 This variable contains a list of packages suitable for a fully-virtualized guest.
29323 @deftp {Data Type} debootstrap-configuration
29325 This data type creates configuration files suitable for the debootstrap OS provider.
29328 @item @code{hooks} (default: @code{%default-debootstrap-hooks})
29329 When not @code{#f}, this must be a G-expression that specifies a directory with
29330 scripts that will run when the OS is installed. It can also be a list of
29331 @code{(name . file-like)} pairs. For example:
29334 `((99-hello-world . ,(plain-file "#!/bin/sh\necho Hello, World")))
29337 That will create a directory with one executable named @code{99-hello-world}
29338 and run it every time this variant is installed. If set to @code{#f}, hooks
29339 in @file{/etc/ganeti/instance-debootstrap/hooks} will be used, if any.
29340 @item @code{proxy} (default: @code{#f})
29341 Optional HTTP proxy to use.
29342 @item @code{mirror} (default: @code{#f})
29343 The Debian mirror. Typically something like @code{http://ftp.no.debian.org/debian}.
29344 The default varies depending on the distribution.
29345 @item @code{arch} (default: @code{#f})
29346 The dpkg architecture. Set to @code{armhf} to debootstrap an ARMv7 instance
29347 on an AArch64 host. Default is to use the current system architecture.
29348 @item @code{suite} (default: @code{"stable"})
29349 When set, this must be a Debian distribution ``suite'' such as @code{buster}
29350 or @code{focal}. If set to @code{#f}, the default for the OS provider is used.
29351 @item @code{extra-pkgs} (default: @code{%default-debootstrap-extra-pkgs})
29352 List of extra packages that will get installed by dpkg in addition
29353 to the minimal system.
29354 @item @code{components} (default: @code{#f})
29355 When set, must be a list of Debian repository ``components''. For example
29356 @code{'("main" "contrib")}.
29357 @item @code{generate-cache?} (default: @code{#t})
29358 Whether to automatically cache the generated debootstrap archive.
29359 @item @code{clean-cache} (default: @code{14})
29360 Discard the cache after this amount of days. Use @code{#f} to never
29362 @item @code{partition-style} (default: @code{'msdos})
29363 The type of partition to create. When set, it must be one of
29364 @code{'msdos}, @code{'none} or a string.
29365 @item @code{partition-alignment} (default: @code{2048})
29366 Alignment of the partition in sectors.
29370 @deffn {Scheme Procedure} debootstrap-variant @var{name} @var{configuration}
29371 This is a helper procedure that creates a @code{ganeti-os-variant} record. It
29372 takes two parameters: a name and a @code{debootstrap-configuration} object.
29375 @deffn {Scheme Procedure} debootstrap-os @var{variants}@dots{}
29376 This is a helper procedure that creates a @code{ganeti-os} record. It takes
29377 a list of variants created with @code{debootstrap-variant}.
29380 @deffn {Scheme Procedure} guix-variant @var{name} @var{configuration}
29381 This is a helper procedure that creates a @code{ganeti-os-variant} record for
29382 use with the Guix OS provider. It takes a name and a G-expression that returns
29383 a ``file-like'' (@pxref{G-Expressions, file-like objects}) object containing a
29384 Guix System configuration.
29387 @deffn {Scheme Procedure} guix-os @var{variants}@dots{}
29388 This is a helper procedure that creates a @code{ganeti-os} record. It
29389 takes a list of variants produced by @code{guix-variant}.
29392 @defvr {Scheme Variable} %default-debootstrap-variants
29393 This is a convenience variable to make the debootstrap provider work
29394 ``out of the box'' without users having to declare variants manually. It
29395 contains a single debootstrap variant with the default configuration:
29398 (list (debootstrap-variant
29400 (debootstrap-configuration)))
29404 @defvr {Scheme Variable} %default-guix-variants
29405 This is a convenience variable to make the Guix OS provider work without
29406 additional configuration. It creates a virtual machine that has an SSH
29407 server, a serial console, and authorizes the Ganeti hosts SSH keys.
29410 (list (guix-variant
29412 (file-append ganeti-instance-guix
29413 "/share/doc/ganeti-instance-guix/examples/dynamic.scm")))
29417 Users can implement support for OS providers unbeknownst to Guix by extending
29418 the @code{ganeti-os} and @code{ganeti-os-variant} records appropriately.
29424 (extension ".conf")
29426 (list (ganeti-os-variant
29428 (configuration (plain-file "bar" "this is fine"))))))
29431 That creates @file{/etc/ganeti/instance-custom/variants/foo.conf} which points
29432 to a file in the store with contents @code{this is fine}. It also creates
29433 @file{/etc/ganeti/instance-custom/variants/variants.list} with contents @code{foo}.
29435 Obviously this may not work for all OS providers out there. If you find the
29436 interface limiting, please reach out to @email{guix-devel@@gnu.org}.
29438 The rest of this section documents the various services that are included by
29439 @code{ganeti-service-type}.
29441 @defvr {Scheme Variable} ganeti-noded-service-type
29442 @command{ganeti-noded} is the daemon responsible for node-specific functions
29443 within the Ganeti system. The value of this service must be a
29444 @code{ganeti-noded-configuration} object.
29447 @deftp {Data Type} ganeti-noded-configuration
29448 This is the configuration for the @code{ganeti-noded} service.
29451 @item @code{ganeti} (default: @code{ganeti})
29452 The @code{ganeti} package to use for this service.
29454 @item @code{port} (default: @code{1811})
29455 The TCP port on which the node daemon listens for network requests.
29457 @item @code{address} (default: @code{"0.0.0.0"})
29458 The network address that the daemon will bind to. The default address means
29459 bind to all available addresses.
29461 @item @code{interface} (default: @code{#f})
29462 When this is set, it must be a specific network interface (e.g.@: @code{eth0})
29463 that the daemon will bind to.
29465 @item @code{max-clients} (default: @code{20})
29466 This sets a limit on the maximum number of simultaneous client connections
29467 that the daemon will handle. Connections above this count are accepted, but
29468 no responses will be sent until enough connections have closed.
29470 @item @code{ssl?} (default: @code{#t})
29471 Whether to use SSL/TLS to encrypt network communications. The certificate
29472 is automatically provisioned by the cluster and can be rotated with
29473 @command{gnt-cluster renew-crypto}.
29475 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
29476 This can be used to provide a specific encryption key for TLS communications.
29478 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
29479 This can be used to provide a specific certificate for TLS communications.
29481 @item @code{debug?} (default: @code{#f})
29482 When true, the daemon performs additional logging for debugging purposes.
29483 Note that this will leak encryption details to the log files, use with caution.
29488 @defvr {Scheme Variable} ganeti-confd-service-type
29489 @command{ganeti-confd} answers queries related to the configuration of a
29490 Ganeti cluster. The purpose of this daemon is to have a highly available
29491 and fast way to query cluster configuration values. It is automatically
29492 active on all @dfn{master candidates}. The value of this service must be a
29493 @code{ganeti-confd-configuration} object.
29497 @deftp {Data Type} ganeti-confd-configuration
29498 This is the configuration for the @code{ganeti-confd} service.
29501 @item @code{ganeti} (default: @code{ganeti})
29502 The @code{ganeti} package to use for this service.
29504 @item @code{port} (default: @code{1814})
29505 The UDP port on which to listen for network requests.
29507 @item @code{address} (default: @code{"0.0.0.0"})
29508 Network address that the daemon will bind to.
29510 @item @code{debug?} (default: @code{#f})
29511 When true, the daemon performs additional logging for debugging purposes.
29516 @defvr {Scheme Variable} ganeti-wconfd-service-type
29517 @command{ganeti-wconfd} is the daemon that has authoritative knowledge
29518 about the cluster configuration and is the only entity that can accept
29519 changes to it. All jobs that need to modify the configuration will do so
29520 by sending appropriate requests to this daemon. It only runs on the
29521 @dfn{master node} and will automatically disable itself on other nodes.
29523 The value of this service must be a
29524 @code{ganeti-wconfd-configuration} object.
29527 @deftp {Data Type} ganeti-wconfd-configuration
29528 This is the configuration for the @code{ganeti-wconfd} service.
29531 @item @code{ganeti} (default: @code{ganeti})
29532 The @code{ganeti} package to use for this service.
29534 @item @code{no-voting?} (default: @code{#f})
29535 The daemon will refuse to start if the majority of cluster nodes does not
29536 agree that it is running on the master node. Set to @code{#t} to start
29537 even if a quorum can not be reached (dangerous, use with caution).
29539 @item @code{debug?} (default: @code{#f})
29540 When true, the daemon performs additional logging for debugging purposes.
29545 @defvr {Scheme Variable} ganeti-luxid-service-type
29546 @command{ganeti-luxid} is a daemon used to answer queries related to the
29547 configuration and the current live state of a Ganeti cluster. Additionally,
29548 it is the authoritative daemon for the Ganeti job queue. Jobs can be
29549 submitted via this daemon and it schedules and starts them.
29551 It takes a @code{ganeti-luxid-configuration} object.
29554 @deftp {Data Type} ganeti-luxid-configuration
29555 This is the configuration for the @code{ganeti-wconfd} service.
29558 @item @code{ganeti} (default: @code{ganeti})
29559 The @code{ganeti} package to use for this service.
29561 @item @code{no-voting?} (default: @code{#f})
29562 The daemon will refuse to start if it cannot verify that the majority of
29563 cluster nodes believes that it is running on the master node. Set to
29564 @code{#t} to ignore such checks and start anyway (this can be dangerous).
29566 @item @code{debug?} (default: @code{#f})
29567 When true, the daemon performs additional logging for debugging purposes.
29572 @defvr {Scheme Variable} ganeti-rapi-service-type
29573 @command{ganeti-rapi} provides a remote API for Ganeti clusters. It runs on
29574 the master node and can be used to perform cluster actions programmatically
29575 via a JSON-based RPC protocol.
29577 Most query operations are allowed without authentication (unless
29578 @var{require-authentication?} is set), whereas write operations require
29579 explicit authorization via the @file{/var/lib/ganeti/rapi/users} file. See
29580 the @url{http://docs.ganeti.org/ganeti/master/html/rapi.html, Ganeti Remote
29581 API documentation} for more information.
29583 The value of this service must be a @code{ganeti-rapi-configuration} object.
29586 @deftp {Data Type} ganeti-rapi-configuration
29587 This is the configuration for the @code{ganeti-rapi} service.
29590 @item @code{ganeti} (default: @code{ganeti})
29591 The @code{ganeti} package to use for this service.
29593 @item @code{require-authentication?} (default: @code{#f})
29594 Whether to require authentication even for read-only operations.
29596 @item @code{port} (default: @code{5080})
29597 The TCP port on which to listen to API requests.
29599 @item @code{address} (default: @code{"0.0.0.0"})
29600 The network address that the service will bind to. By default it listens
29601 on all configured addresses.
29603 @item @code{interface} (default: @code{#f})
29604 When set, it must specify a specific network interface such as @code{eth0}
29605 that the daemon will bind to.
29607 @item @code{max-clients} (default: @code{20})
29608 The maximum number of simultaneous client requests to handle. Further
29609 connections are allowed, but no responses are sent until enough connections
29612 @item @code{ssl?} (default: @code{#t})
29613 Whether to use SSL/TLS encryption on the RAPI port.
29615 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
29616 This can be used to provide a specific encryption key for TLS communications.
29618 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
29619 This can be used to provide a specific certificate for TLS communications.
29621 @item @code{debug?} (default: @code{#f})
29622 When true, the daemon performs additional logging for debugging purposes.
29623 Note that this will leak encryption details to the log files, use with caution.
29628 @defvr {Scheme Variable} ganeti-kvmd-service-type
29629 @command{ganeti-kvmd} is responsible for determining whether a given KVM
29630 instance was shut down by an administrator or a user. Normally Ganeti will
29631 restart an instance that was not stopped through Ganeti itself. If the
29632 cluster option @code{user_shutdown} is true, this daemon monitors the
29633 @code{QMP} socket provided by QEMU and listens for shutdown events, and
29634 marks the instance as @dfn{USER_down} instead of @dfn{ERROR_down} when
29635 it shuts down gracefully by itself.
29637 It takes a @code{ganeti-kvmd-configuration} object.
29640 @deftp {Data Type} ganeti-kvmd-configuration
29643 @item @code{ganeti} (default: @code{ganeti})
29644 The @code{ganeti} package to use for this service.
29646 @item @code{debug?} (default: @code{#f})
29647 When true, the daemon performs additional logging for debugging purposes.
29652 @defvr {Scheme Variable} ganeti-mond-service-type
29653 @command{ganeti-mond} is an optional daemon that provides Ganeti monitoring
29654 functionality. It is responsible for running data collectors and publish the
29655 collected information through a HTTP interface.
29657 It takes a @code{ganeti-mond-configuration} object.
29660 @deftp {Data Type} ganeti-mond-configuration
29663 @item @code{ganeti} (default: @code{ganeti})
29664 The @code{ganeti} package to use for this service.
29666 @item @code{port} (default: @code{1815})
29667 The port on which the daemon will listen.
29669 @item @code{address} (default: @code{"0.0.0.0"})
29670 The network address that the daemon will bind to. By default it binds to all
29671 available interfaces.
29673 @item @code{debug?} (default: @code{#f})
29674 When true, the daemon performs additional logging for debugging purposes.
29679 @defvr {Scheme Variable} ganeti-metad-service-type
29680 @command{ganeti-metad} is an optional daemon that can be used to provide
29681 information about the cluster to instances or OS install scripts.
29683 It takes a @code{ganeti-metad-configuration} object.
29686 @deftp {Data Type} ganeti-metad-configuration
29689 @item @code{ganeti} (default: @code{ganeti})
29690 The @code{ganeti} package to use for this service.
29692 @item @code{port} (default: @code{80})
29693 The port on which the daemon will listen.
29695 @item @code{address} (default: @code{#f})
29696 If set, the daemon will bind to this address only. If left unset, the behavior
29697 depends on the cluster configuration.
29699 @item @code{debug?} (default: @code{#f})
29700 When true, the daemon performs additional logging for debugging purposes.
29705 @defvr {Scheme Variable} ganeti-watcher-service-type
29706 @command{ganeti-watcher} is a script designed to run periodically and ensure
29707 the health of a cluster. It will automatically restart instances that have
29708 stopped without Ganeti's consent, and repairs DRBD links in case a node has
29709 rebooted. It also archives old cluster jobs and restarts Ganeti daemons
29710 that are not running. If the cluster parameter @code{ensure_node_health}
29711 is set, the watcher will also shutdown instances and DRBD devices if the
29712 node it is running on is declared offline by known master candidates.
29714 It can be paused on all nodes with @command{gnt-cluster watcher pause}.
29716 The service takes a @code{ganeti-watcher-configuration} object.
29719 @deftp {Data Type} ganeti-watcher-configuration
29722 @item @code{ganeti} (default: @code{ganeti})
29723 The @code{ganeti} package to use for this service.
29725 @item @code{schedule} (default: @code{'(next-second-from (next-minute (range 0 60 5)))})
29726 How often to run the script. The default is every five minutes.
29728 @item @code{rapi-ip} (default: @code{#f})
29729 This option needs to be specified only if the RAPI daemon is configured to use
29730 a particular interface or address. By default the cluster address is used.
29732 @item @code{job-age} (default: @code{(* 6 3600)})
29733 Archive cluster jobs older than this age, specified in seconds. The default
29734 is 6 hours. This keeps @command{gnt-job list} manageable.
29736 @item @code{verify-disks?} (default: @code{#t})
29737 If this is @code{#f}, the watcher will not try to repair broken DRBD links
29738 automatically. Administrators will need to use @command{gnt-cluster verify-disks}
29741 @item @code{debug?} (default: @code{#f})
29742 When @code{#t}, the script performs additional logging for debugging purposes.
29747 @defvr {Scheme Variable} ganeti-cleaner-service-type
29748 @command{ganeti-cleaner} is a script designed to run periodically and remove
29749 old files from the cluster. This service type controls two @dfn{cron jobs}:
29750 one intended for the master node that permanently purges old cluster jobs,
29751 and one intended for every node that removes expired X509 certificates, keys,
29752 and outdated @command{ganeti-watcher} information. Like all Ganeti services,
29753 it is safe to include even on non-master nodes as it will disable itself as
29756 It takes a @code{ganeti-cleaner-configuration} object.
29759 @deftp {Data Type} ganeti-cleaner-configuration
29762 @item @code{ganeti} (default: @code{ganeti})
29763 The @code{ganeti} package to use for the @command{gnt-cleaner} command.
29765 @item @code{master-schedule} (default: @code{"45 1 * * *"})
29766 How often to run the master cleaning job. The default is once per day, at
29769 @item @code{node-schedule} (default: @code{"45 2 * * *"})
29770 How often to run the node cleaning job. The default is once per day, at
29776 @node Version Control Services
29777 @subsection Version Control Services
29779 The @code{(gnu services version-control)} module provides a service to
29780 allow remote access to local Git repositories. There are three options:
29781 the @code{git-daemon-service}, which provides access to repositories via
29782 the @code{git://} unsecured TCP-based protocol, extending the
29783 @code{nginx} web server to proxy some requests to
29784 @code{git-http-backend}, or providing a web interface with
29785 @code{cgit-service-type}.
29787 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
29789 Return a service that runs @command{git daemon}, a simple TCP server to
29790 expose repositories over the Git protocol for anonymous access.
29792 The optional @var{config} argument should be a
29793 @code{<git-daemon-configuration>} object, by default it allows read-only
29794 access to exported@footnote{By creating the magic file
29795 @file{git-daemon-export-ok} in the repository directory.} repositories under
29800 @deftp {Data Type} git-daemon-configuration
29801 Data type representing the configuration for @code{git-daemon-service}.
29804 @item @code{package} (default: @code{git})
29805 Package object of the Git distributed version control system.
29807 @item @code{export-all?} (default: @code{#f})
29808 Whether to allow access for all Git repositories, even if they do not
29809 have the @file{git-daemon-export-ok} file.
29811 @item @code{base-path} (default: @file{/srv/git})
29812 Whether to remap all the path requests as relative to the given path.
29813 If you run @command{git daemon} with @code{(base-path "/srv/git")} on
29814 @samp{example.com}, then if you later try to pull
29815 @indicateurl{git://example.com/hello.git}, git daemon will interpret the
29816 path as @file{/srv/git/hello.git}.
29818 @item @code{user-path} (default: @code{#f})
29819 Whether to allow @code{~user} notation to be used in requests. When
29820 specified with empty string, requests to
29821 @indicateurl{git://host/~alice/foo} is taken as a request to access
29822 @code{foo} repository in the home directory of user @code{alice}. If
29823 @code{(user-path "@var{path}")} is specified, the same request is taken
29824 as a request to access @file{@var{path}/foo} repository in the home
29825 directory of user @code{alice}.
29827 @item @code{listen} (default: @code{'()})
29828 Whether to listen on specific IP addresses or hostnames, defaults to
29831 @item @code{port} (default: @code{#f})
29832 Whether to listen on an alternative port, which defaults to 9418.
29834 @item @code{whitelist} (default: @code{'()})
29835 If not empty, only allow access to this list of directories.
29837 @item @code{extra-options} (default: @code{'()})
29838 Extra options will be passed to @command{git daemon}, please run
29839 @command{man git-daemon} for more information.
29844 The @code{git://} protocol lacks authentication. When you pull from a
29845 repository fetched via @code{git://}, you don't know whether the data you
29846 receive was modified or is even coming from the specified host, and your
29847 connection is subject to eavesdropping. It's better to use an authenticated
29848 and encrypted transport, such as @code{https}. Although Git allows you
29849 to serve repositories using unsophisticated file-based web servers,
29850 there is a faster protocol implemented by the @code{git-http-backend}
29851 program. This program is the back-end of a proper Git web service. It
29852 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
29853 on running the necessary @code{fcgiwrap} daemon.
29855 Guix has a separate configuration data type for serving Git repositories
29858 @deftp {Data Type} git-http-configuration
29859 Data type representing the configuration for a future
29860 @code{git-http-service-type}; can currently be used to configure Nginx
29861 through @code{git-http-nginx-location-configuration}.
29864 @item @code{package} (default: @var{git})
29865 Package object of the Git distributed version control system.
29867 @item @code{git-root} (default: @file{/srv/git})
29868 Directory containing the Git repositories to expose to the world.
29870 @item @code{export-all?} (default: @code{#f})
29871 Whether to expose access for all Git repositories in @var{git-root},
29872 even if they do not have the @file{git-daemon-export-ok} file.
29874 @item @code{uri-path} (default: @samp{/git/})
29875 Path prefix for Git access. With the default @samp{/git/} prefix, this
29876 will map @indicateurl{http://@var{server}/git/@var{repo}.git} to
29877 @file{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
29878 with this prefix are not passed on to this Git instance.
29880 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
29881 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
29886 There is no @code{git-http-service-type}, currently; instead you can
29887 create an @code{nginx-location-configuration} from a
29888 @code{git-http-configuration} and then add that location to a web
29891 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
29892 [config=(git-http-configuration)]
29893 Compute an @code{nginx-location-configuration} that corresponds to the
29894 given Git http configuration. An example nginx service definition to
29895 serve the default @file{/srv/git} over HTTPS might be:
29898 (service nginx-service-type
29899 (nginx-configuration
29902 (nginx-server-configuration
29903 (listen '("443 ssl"))
29904 (server-name "git.my-host.org")
29906 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
29907 (ssl-certificate-key
29908 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
29911 (git-http-nginx-location-configuration
29912 (git-http-configuration (uri-path "/"))))))))))
29915 This example assumes that you are using Let's Encrypt to get your TLS
29916 certificate. @xref{Certificate Services}. The default @code{certbot}
29917 service will redirect all HTTP traffic on @code{git.my-host.org} to
29918 HTTPS@. You will also need to add an @code{fcgiwrap} proxy to your
29919 system services. @xref{Web Services}.
29922 @subsubheading Cgit Service
29924 @cindex Cgit service
29925 @cindex Git, web interface
29926 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
29927 repositories written in C.
29929 The following example will configure the service with default values.
29930 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
29933 (service cgit-service-type)
29936 The @code{file-object} type designates either a file-like object
29937 (@pxref{G-Expressions, file-like objects}) or a string.
29939 @c %start of fragment
29941 Available @code{cgit-configuration} fields are:
29943 @deftypevr {@code{cgit-configuration} parameter} package package
29948 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
29949 NGINX configuration.
29953 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
29954 Specifies a command which will be invoked to format the content of about
29955 pages (both top-level and for each repository).
29957 Defaults to @samp{""}.
29961 @deftypevr {@code{cgit-configuration} parameter} string agefile
29962 Specifies a path, relative to each repository path, which can be used to
29963 specify the date and time of the youngest commit in the repository.
29965 Defaults to @samp{""}.
29969 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
29970 Specifies a command that will be invoked for authenticating repository
29973 Defaults to @samp{""}.
29977 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
29978 Flag which, when set to @samp{age}, enables date ordering in the branch
29979 ref list, and when set @samp{name} enables ordering by branch name.
29981 Defaults to @samp{"name"}.
29985 @deftypevr {@code{cgit-configuration} parameter} string cache-root
29986 Path used to store the cgit cache entries.
29988 Defaults to @samp{"/var/cache/cgit"}.
29992 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
29993 Number which specifies the time-to-live, in minutes, for the cached
29994 version of repository pages accessed with a fixed SHA1.
29996 Defaults to @samp{-1}.
30000 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
30001 Number which specifies the time-to-live, in minutes, for the cached
30002 version of repository pages accessed without a fixed SHA1.
30004 Defaults to @samp{5}.
30008 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
30009 Number which specifies the time-to-live, in minutes, for the cached
30010 version of the repository summary page.
30012 Defaults to @samp{5}.
30016 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
30017 Number which specifies the time-to-live, in minutes, for the cached
30018 version of the repository index page.
30020 Defaults to @samp{5}.
30024 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
30025 Number which specifies the time-to-live, in minutes, for the result of
30026 scanning a path for Git repositories.
30028 Defaults to @samp{15}.
30032 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
30033 Number which specifies the time-to-live, in minutes, for the cached
30034 version of the repository about page.
30036 Defaults to @samp{15}.
30040 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
30041 Number which specifies the time-to-live, in minutes, for the cached
30042 version of snapshots.
30044 Defaults to @samp{5}.
30048 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
30049 The maximum number of entries in the cgit cache. When set to @samp{0},
30050 caching is disabled.
30052 Defaults to @samp{0}.
30056 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
30057 Sort items in the repo list case sensitively.
30059 Defaults to @samp{#t}.
30063 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
30064 List of common prefixes which, when combined with a repository URL,
30065 generates valid clone URLs for the repository.
30067 Defaults to @samp{()}.
30071 @deftypevr {@code{cgit-configuration} parameter} list clone-url
30072 List of @code{clone-url} templates.
30074 Defaults to @samp{()}.
30078 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
30079 Command which will be invoked to format commit messages.
30081 Defaults to @samp{""}.
30085 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
30086 Flag which, when set to @samp{date}, enables strict date ordering in the
30087 commit log, and when set to @samp{topo} enables strict topological
30090 Defaults to @samp{"git log"}.
30094 @deftypevr {@code{cgit-configuration} parameter} file-object css
30095 URL which specifies the css document to include in all cgit pages.
30097 Defaults to @samp{"/share/cgit/cgit.css"}.
30101 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
30102 Specifies a command which will be invoked to format names and email
30103 address of committers, authors, and taggers, as represented in various
30104 places throughout the cgit interface.
30106 Defaults to @samp{""}.
30110 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
30111 Flag which, when set to @samp{#t}, will make cgit generate a HTML
30112 fragment suitable for embedding in other HTML pages.
30114 Defaults to @samp{#f}.
30118 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
30119 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
30120 commit history graph to the left of the commit messages in the
30121 repository log page.
30123 Defaults to @samp{#f}.
30127 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
30128 Flag which, when set to @samp{#t}, allows all filter settings to be
30129 overridden in repository-specific cgitrc files.
30131 Defaults to @samp{#f}.
30135 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
30136 Flag which, when set to @samp{#t}, allows users to follow a file in the
30139 Defaults to @samp{#f}.
30143 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
30144 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
30147 Defaults to @samp{#t}.
30151 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
30152 Flag which, when set to @samp{#t}, will make cgit generate extra links
30153 "summary", "commit", "tree" for each repo in the repository index.
30155 Defaults to @samp{#f}.
30159 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
30160 Flag which, when set to @samp{#t}, will make cgit display the owner of
30161 each repo in the repository index.
30163 Defaults to @samp{#t}.
30167 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
30168 Flag which, when set to @samp{#t}, will make cgit print the number of
30169 modified files for each commit on the repository log page.
30171 Defaults to @samp{#f}.
30175 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
30176 Flag which, when set to @samp{#t}, will make cgit print the number of
30177 added and removed lines for each commit on the repository log page.
30179 Defaults to @samp{#f}.
30183 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
30184 Flag which, when set to @code{#t}, will make cgit display remote
30185 branches in the summary and refs views.
30187 Defaults to @samp{#f}.
30191 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
30192 Flag which, when set to @code{1}, will make cgit use the subject of the
30193 parent commit as link text when generating links to parent commits in
30196 Defaults to @samp{#f}.
30200 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
30201 Flag which, when set to @samp{#t}, will make cgit use the subject of the
30202 parent commit as link text when generating links to parent commits in
30205 Defaults to @samp{#f}.
30209 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
30210 Flag which, when set to @samp{#t}, will make cgit generate linenumber
30211 links for plaintext blobs printed in the tree view.
30213 Defaults to @samp{#t}.
30217 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
30218 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
30219 set any repo specific settings.
30221 Defaults to @samp{#f}.
30225 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
30226 URL used as link to a shortcut icon for cgit.
30228 Defaults to @samp{"/favicon.ico"}.
30232 @deftypevr {@code{cgit-configuration} parameter} string footer
30233 The content of the file specified with this option will be included
30234 verbatim at the bottom of all pages (i.e.@: it replaces the standard
30235 "generated by..."@: message).
30237 Defaults to @samp{""}.
30241 @deftypevr {@code{cgit-configuration} parameter} string head-include
30242 The content of the file specified with this option will be included
30243 verbatim in the HTML HEAD section on all pages.
30245 Defaults to @samp{""}.
30249 @deftypevr {@code{cgit-configuration} parameter} string header
30250 The content of the file specified with this option will be included
30251 verbatim at the top of all pages.
30253 Defaults to @samp{""}.
30257 @deftypevr {@code{cgit-configuration} parameter} file-object include
30258 Name of a configfile to include before the rest of the current config-
30261 Defaults to @samp{""}.
30265 @deftypevr {@code{cgit-configuration} parameter} string index-header
30266 The content of the file specified with this option will be included
30267 verbatim above the repository index.
30269 Defaults to @samp{""}.
30273 @deftypevr {@code{cgit-configuration} parameter} string index-info
30274 The content of the file specified with this option will be included
30275 verbatim below the heading on the repository index page.
30277 Defaults to @samp{""}.
30281 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
30282 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
30283 in the servers timezone.
30285 Defaults to @samp{#f}.
30289 @deftypevr {@code{cgit-configuration} parameter} file-object logo
30290 URL which specifies the source of an image which will be used as a logo
30293 Defaults to @samp{"/share/cgit/cgit.png"}.
30297 @deftypevr {@code{cgit-configuration} parameter} string logo-link
30298 URL loaded when clicking on the cgit logo image.
30300 Defaults to @samp{""}.
30304 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
30305 Command which will be invoked to format the Owner column of the main
30308 Defaults to @samp{""}.
30312 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
30313 Number of items to display in atom feeds view.
30315 Defaults to @samp{10}.
30319 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
30320 Number of entries to list per page in "log" view.
30322 Defaults to @samp{50}.
30326 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
30327 Number of commit message characters to display in "log" view.
30329 Defaults to @samp{80}.
30333 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
30334 Specifies the number of entries to list per page on the repository index
30337 Defaults to @samp{50}.
30341 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
30342 Specifies the maximum number of repo description characters to display
30343 on the repository index page.
30345 Defaults to @samp{80}.
30349 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
30350 Specifies the maximum size of a blob to display HTML for in KBytes.
30352 Defaults to @samp{0}.
30356 @deftypevr {@code{cgit-configuration} parameter} string max-stats
30357 Maximum statistics period. Valid values are @samp{week},@samp{month},
30358 @samp{quarter} and @samp{year}.
30360 Defaults to @samp{""}.
30364 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
30365 Mimetype for the specified filename extension.
30367 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
30368 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
30369 "image/png") (svg "image/svg+xml"))}.
30373 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
30374 Specifies the file to use for automatic mimetype lookup.
30376 Defaults to @samp{""}.
30380 @deftypevr {@code{cgit-configuration} parameter} string module-link
30381 Text which will be used as the formatstring for a hyperlink when a
30382 submodule is printed in a directory listing.
30384 Defaults to @samp{""}.
30388 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
30389 If set to the value @samp{#t} caching will be disabled.
30391 Defaults to @samp{#f}.
30395 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
30396 If set to @samp{#t} showing full author email addresses will be
30399 Defaults to @samp{#f}.
30403 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
30404 Flag which, when set to @samp{#t}, will make cgit omit the standard
30405 header on all pages.
30407 Defaults to @samp{#f}.
30411 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
30412 A list of subdirectories inside of @code{repository-directory}, relative
30413 to it, that should loaded as Git repositories. An empty list means that
30414 all subdirectories will be loaded.
30416 Defaults to @samp{()}.
30420 @deftypevr {@code{cgit-configuration} parameter} file-object readme
30421 Text which will be used as default value for @code{cgit-repo-readme}.
30423 Defaults to @samp{""}.
30427 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
30428 If set to @code{#t} and @code{repository-directory} is enabled, if any
30429 repositories are found with a suffix of @code{.git}, this suffix will be
30430 removed for the URL and name.
30432 Defaults to @samp{#f}.
30436 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
30437 Maximum number of files to consider when detecting renames.
30439 Defaults to @samp{-1}.
30443 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
30444 The way in which repositories in each section are sorted.
30446 Defaults to @samp{""}.
30450 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
30451 Text used as content for the @code{robots} meta-tag.
30453 Defaults to @samp{("noindex" "nofollow")}.
30457 @deftypevr {@code{cgit-configuration} parameter} string root-desc
30458 Text printed below the heading on the repository index page.
30460 Defaults to @samp{"a fast webinterface for the git dscm"}.
30464 @deftypevr {@code{cgit-configuration} parameter} string root-readme
30465 The content of the file specified with this option will be included
30466 verbatim below the ``about'' link on the repository index page.
30468 Defaults to @samp{""}.
30472 @deftypevr {@code{cgit-configuration} parameter} string root-title
30473 Text printed as heading on the repository index page.
30475 Defaults to @samp{""}.
30479 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
30480 If set to @samp{#t} and repository-directory is enabled,
30481 repository-directory will recurse into directories whose name starts
30482 with a period. Otherwise, repository-directory will stay away from such
30483 directories, considered as ``hidden''. Note that this does not apply to
30484 the @file{.git} directory in non-bare repos.
30486 Defaults to @samp{#f}.
30490 @deftypevr {@code{cgit-configuration} parameter} list snapshots
30491 Text which specifies the default set of snapshot formats that cgit
30492 generates links for.
30494 Defaults to @samp{()}.
30498 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
30499 Name of the directory to scan for repositories (represents
30502 Defaults to @samp{"/srv/git"}.
30506 @deftypevr {@code{cgit-configuration} parameter} string section
30507 The name of the current repository section - all repositories defined
30508 after this option will inherit the current section name.
30510 Defaults to @samp{""}.
30514 @deftypevr {@code{cgit-configuration} parameter} string section-sort
30515 Flag which, when set to @samp{1}, will sort the sections on the
30516 repository listing by name.
30518 Defaults to @samp{""}.
30522 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
30523 A number which, if defined prior to repository-directory, specifies how
30524 many path elements from each repo path to use as a default section name.
30526 Defaults to @samp{0}.
30530 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
30531 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
30534 Defaults to @samp{#f}.
30538 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
30539 Specifies a command which will be invoked to format plaintext blobs in
30542 Defaults to @samp{""}.
30546 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
30547 Specifies the number of branches to display in the repository ``summary''
30550 Defaults to @samp{10}.
30554 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
30555 Specifies the number of log entries to display in the repository
30558 Defaults to @samp{10}.
30562 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
30563 Specifies the number of tags to display in the repository ``summary''
30566 Defaults to @samp{10}.
30570 @deftypevr {@code{cgit-configuration} parameter} string strict-export
30571 Filename which, if specified, needs to be present within the repository
30572 for cgit to allow access to that repository.
30574 Defaults to @samp{""}.
30578 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
30579 URL which, if specified, will be used as root for all cgit links.
30581 Defaults to @samp{"/"}.
30585 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
30586 A list of @dfn{cgit-repo} records to use with config.
30588 Defaults to @samp{()}.
30590 Available @code{repository-cgit-configuration} fields are:
30592 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
30593 A mask of snapshot formats for this repo that cgit generates links for,
30594 restricted by the global @code{snapshots} setting.
30596 Defaults to @samp{()}.
30600 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
30601 Override the default @code{source-filter}.
30603 Defaults to @samp{""}.
30607 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
30608 The relative URL used to access the repository.
30610 Defaults to @samp{""}.
30614 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
30615 Override the default @code{about-filter}.
30617 Defaults to @samp{""}.
30621 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
30622 Flag which, when set to @samp{age}, enables date ordering in the branch
30623 ref list, and when set to @samp{name} enables ordering by branch name.
30625 Defaults to @samp{""}.
30629 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
30630 A list of URLs which can be used to clone repo.
30632 Defaults to @samp{()}.
30636 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
30637 Override the default @code{commit-filter}.
30639 Defaults to @samp{""}.
30643 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
30644 Flag which, when set to @samp{date}, enables strict date ordering in the
30645 commit log, and when set to @samp{topo} enables strict topological
30648 Defaults to @samp{""}.
30652 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
30653 The name of the default branch for this repository. If no such branch
30654 exists in the repository, the first branch name (when sorted) is used as
30655 default instead. By default branch pointed to by HEAD, or ``master'' if
30656 there is no suitable HEAD.
30658 Defaults to @samp{""}.
30662 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
30663 The value to show as repository description.
30665 Defaults to @samp{""}.
30669 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
30670 The value to show as repository homepage.
30672 Defaults to @samp{""}.
30676 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
30677 Override the default @code{email-filter}.
30679 Defaults to @samp{""}.
30683 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
30684 A flag which can be used to disable the global setting
30685 @code{enable-commit-graph?}.
30687 Defaults to @samp{disabled}.
30691 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
30692 A flag which can be used to disable the global setting
30693 @code{enable-log-filecount?}.
30695 Defaults to @samp{disabled}.
30699 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
30700 A flag which can be used to disable the global setting
30701 @code{enable-log-linecount?}.
30703 Defaults to @samp{disabled}.
30707 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
30708 Flag which, when set to @code{#t}, will make cgit display remote
30709 branches in the summary and refs views.
30711 Defaults to @samp{disabled}.
30715 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
30716 A flag which can be used to override the global setting
30717 @code{enable-subject-links?}.
30719 Defaults to @samp{disabled}.
30723 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
30724 A flag which can be used to override the global setting
30725 @code{enable-html-serving?}.
30727 Defaults to @samp{disabled}.
30731 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
30732 Flag which, when set to @code{#t}, hides the repository from the
30735 Defaults to @samp{#f}.
30739 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
30740 Flag which, when set to @samp{#t}, ignores the repository.
30742 Defaults to @samp{#f}.
30746 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
30747 URL which specifies the source of an image which will be used as a logo
30748 on this repo’s pages.
30750 Defaults to @samp{""}.
30754 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
30755 URL loaded when clicking on the cgit logo image.
30757 Defaults to @samp{""}.
30761 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
30762 Override the default @code{owner-filter}.
30764 Defaults to @samp{""}.
30768 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
30769 Text which will be used as the formatstring for a hyperlink when a
30770 submodule is printed in a directory listing. The arguments for the
30771 formatstring are the path and SHA1 of the submodule commit.
30773 Defaults to @samp{""}.
30777 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
30778 Text which will be used as the formatstring for a hyperlink when a
30779 submodule with the specified subdirectory path is printed in a directory
30782 Defaults to @samp{()}.
30786 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
30787 Override the default maximum statistics period.
30789 Defaults to @samp{""}.
30793 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
30794 The value to show as repository name.
30796 Defaults to @samp{""}.
30800 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
30801 A value used to identify the owner of the repository.
30803 Defaults to @samp{""}.
30807 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
30808 An absolute path to the repository directory.
30810 Defaults to @samp{""}.
30814 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
30815 A path (relative to repo) which specifies a file to include verbatim as
30816 the ``About'' page for this repo.
30818 Defaults to @samp{""}.
30822 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
30823 The name of the current repository section - all repositories defined
30824 after this option will inherit the current section name.
30826 Defaults to @samp{""}.
30830 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
30831 Extra options will be appended to cgitrc file.
30833 Defaults to @samp{()}.
30839 @deftypevr {@code{cgit-configuration} parameter} list extra-options
30840 Extra options will be appended to cgitrc file.
30842 Defaults to @samp{()}.
30847 @c %end of fragment
30849 However, it could be that you just want to get a @code{cgitrc} up and
30850 running. In that case, you can pass an @code{opaque-cgit-configuration}
30851 as a record to @code{cgit-service-type}. As its name indicates, an
30852 opaque configuration does not have easy reflective capabilities.
30854 Available @code{opaque-cgit-configuration} fields are:
30856 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
30860 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
30861 The contents of the @code{cgitrc}, as a string.
30864 For example, if your @code{cgitrc} is just the empty string, you
30865 could instantiate a cgit service like this:
30868 (service cgit-service-type
30869 (opaque-cgit-configuration
30873 @subsubheading Gitolite Service
30875 @cindex Gitolite service
30876 @cindex Git, hosting
30877 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
30878 repositories on a central server.
30880 Gitolite can handle multiple repositories and users, and supports flexible
30881 configuration of the permissions for the users on the repositories.
30883 The following example will configure Gitolite using the default @code{git}
30884 user, and the provided SSH public key.
30887 (service gitolite-service-type
30888 (gitolite-configuration
30889 (admin-pubkey (plain-file
30891 "ssh-rsa AAAA... guix@@example.com"))))
30894 Gitolite is configured through a special admin repository which you can clone,
30895 for example, if you setup Gitolite on @code{example.com}, you would run the
30896 following command to clone the admin repository.
30899 git clone git@@example.com:gitolite-admin
30902 When the Gitolite service is activated, the provided @code{admin-pubkey} will
30903 be inserted in to the @file{keydir} directory in the gitolite-admin
30904 repository. If this results in a change in the repository, it will be
30905 committed using the message ``gitolite setup by GNU Guix''.
30907 @deftp {Data Type} gitolite-configuration
30908 Data type representing the configuration for @code{gitolite-service-type}.
30911 @item @code{package} (default: @var{gitolite})
30912 Gitolite package to use.
30914 @item @code{user} (default: @var{git})
30915 User to use for Gitolite. This will be user that you use when accessing
30918 @item @code{group} (default: @var{git})
30919 Group to use for Gitolite.
30921 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
30922 Directory in which to store the Gitolite configuration and repositories.
30924 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
30925 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
30926 representing the configuration for Gitolite.
30928 @item @code{admin-pubkey} (default: @var{#f})
30929 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
30930 setup Gitolite. This will be inserted in to the @file{keydir} directory
30931 within the gitolite-admin repository.
30933 To specify the SSH key as a string, use the @code{plain-file} function.
30936 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
30942 @deftp {Data Type} gitolite-rc-file
30943 Data type representing the Gitolite RC file.
30946 @item @code{umask} (default: @code{#o0077})
30947 This controls the permissions Gitolite sets on the repositories and their
30950 A value like @code{#o0027} will give read access to the group used by Gitolite
30951 (by default: @code{git}). This is necessary when using Gitolite with software
30952 like cgit or gitweb.
30954 @item @code{git-config-keys} (default: @code{""})
30955 Gitolite allows you to set git config values using the @samp{config}
30956 keyword. This setting allows control over the config keys to accept.
30958 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
30959 Set the role names allowed to be used by users running the perms command.
30961 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
30962 This setting controls the commands and features to enable within Gitolite.
30968 @node Game Services
30969 @subsection Game Services
30971 @subsubheading The Battle for Wesnoth Service
30973 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
30974 based tactical strategy game, with several single player campaigns, and
30975 multiplayer games (both networked and local).
30977 @defvar {Scheme Variable} wesnothd-service-type
30978 Service type for the wesnothd service. Its value must be a
30979 @code{wesnothd-configuration} object. To run wesnothd in the default
30980 configuration, instantiate it as:
30983 (service wesnothd-service-type)
30987 @deftp {Data Type} wesnothd-configuration
30988 Data type representing the configuration of @command{wesnothd}.
30991 @item @code{package} (default: @code{wesnoth-server})
30992 The wesnoth server package to use.
30994 @item @code{port} (default: @code{15000})
30995 The port to bind the server to.
31000 @node PAM Mount Service
31001 @subsection PAM Mount Service
31004 The @code{(gnu services pam-mount)} module provides a service allowing
31005 users to mount volumes when they log in. It should be able to mount any
31006 volume format supported by the system.
31008 @defvar {Scheme Variable} pam-mount-service-type
31009 Service type for PAM Mount support.
31012 @deftp {Data Type} pam-mount-configuration
31013 Data type representing the configuration of PAM Mount.
31015 It takes the following parameters:
31019 The configuration rules that will be used to generate
31020 @file{/etc/security/pam_mount.conf.xml}.
31022 The configuration rules are SXML elements (@pxref{SXML,,, guile, GNU
31023 Guile Reference Manual}), and the default ones don't mount anything for
31027 `((debug (@@ (enable "0")))
31028 (mntoptions (@@ (allow ,(string-join
31029 '("nosuid" "nodev" "loop"
31030 "encryption" "fsck" "nonempty"
31031 "allow_root" "allow_other")
31033 (mntoptions (@@ (require "nosuid,nodev")))
31034 (logout (@@ (wait "0")
31038 (mkmountpoint (@@ (enable "1")
31042 Some @code{volume} elements must be added to automatically mount volumes
31043 at login. Here's an example allowing the user @code{alice} to mount her
31044 encrypted @env{HOME} directory and allowing the user @code{bob} to mount
31045 the partition where he stores his data:
31048 (define pam-mount-rules
31049 `((debug (@@ (enable "0")))
31050 (volume (@@ (user "alice")
31053 (mountpoint "/home/alice")))
31054 (volume (@@ (user "bob")
31057 (mountpoint "/home/bob/data")
31058 (options "defaults,autodefrag,compress")))
31059 (mntoptions (@@ (allow ,(string-join
31060 '("nosuid" "nodev" "loop"
31061 "encryption" "fsck" "nonempty"
31062 "allow_root" "allow_other")
31064 (mntoptions (@@ (require "nosuid,nodev")))
31065 (logout (@@ (wait "0")
31069 (mkmountpoint (@@ (enable "1")
31070 (remove "true")))))
31072 (service pam-mount-service-type
31073 (pam-mount-configuration
31074 (rules pam-mount-rules)))
31077 The complete list of possible options can be found in the man page for
31078 @uref{http://pam-mount.sourceforge.net/pam_mount.conf.5.html, pam_mount.conf}.
31083 @node Guix Services
31084 @subsection Guix Services
31086 @subsubheading Guix Build Coordinator
31087 The @uref{https://git.cbaines.net/guix/build-coordinator/,Guix Build
31088 Coordinator} aids in distributing derivation builds among machines
31089 running an @dfn{agent}. The build daemon is still used to build the
31090 derivations, but the Guix Build Coordinator manages allocating builds
31091 and working with the results.
31094 This service is considered experimental. Configuration options may be
31095 changed in a backwards-incompatible manner, and not all features have
31096 been thorougly tested.
31099 The Guix Build Coordinator consists of one @dfn{coordinator}, and one or
31100 more connected @dfn{agent} processes. The coordinator process handles
31101 clients submitting builds, and allocating builds to agents. The agent
31102 processes talk to a build daemon to actually perform the builds, then
31103 send the results back to the coordinator.
31105 There is a script to run the coordinator component of the Guix Build
31106 Coordinator, but the Guix service uses a custom Guile script instead, to
31107 provide better integration with G-expressions used in the configuration.
31109 @defvar {Scheme Variable} guix-build-coordinator-service-type
31110 Service type for the Guix Build Coordinator. Its value must be a
31111 @code{guix-build-coordinator-configuration} object.
31114 @deftp {Data Type} guix-build-coordinator-configuration
31115 Data type representing the configuration of the Guix Build Coordinator.
31118 @item @code{package} (default: @code{guix-build-coordinator})
31119 The Guix Build Coordinator package to use.
31121 @item @code{user} (default: @code{"guix-build-coordinator"})
31122 The system user to run the service as.
31124 @item @code{group} (default: @code{"guix-build-coordinator"})
31125 The system group to run the service as.
31127 @item @code{database-uri-string} (default: @code{"sqlite:///var/lib/guix-build-coordinator/guix_build_coordinator.db"})
31128 The URI to use for the database.
31130 @item @code{agent-communication-uri} (default: @code{"http://0.0.0.0:8745"})
31131 The URI describing how to listen to requests from agent processes.
31133 @item @code{client-communication-uri} (default: @code{"http://127.0.0.1:8746"})
31134 The URI describing how to listen to requests from clients. The client
31135 API allows submitting builds and currently isn't authenticated, so take
31136 care when configuring this value.
31138 @item @code{allocation-strategy} (default: @code{#~basic-build-allocation-strategy})
31139 A G-expression for the allocation strategy to be used. This is a
31140 procedure that takes the datastore as an argument and populates the
31141 allocation plan in the database.
31143 @item @code{hooks} (default: @var{'()})
31144 An association list of hooks. These provide a way to execute arbitrary
31145 code upon certain events, like a build result being processed.
31147 @item @code{guile} (default: @code{guile-3.0-latest})
31148 The Guile package with which to run the Guix Build Coordinator.
31153 @defvar {Scheme Variable} guix-build-coordinator-agent-service-type
31154 Service type for a Guix Build Coordinator agent. Its value must be a
31155 @code{guix-build-coordinator-agent-configuration} object.
31158 @deftp {Data Type} guix-build-coordinator-agent-configuration
31159 Data type representing the configuration a Guix Build Coordinator agent.
31162 @item @code{package} (default: @code{guix-build-coordinator})
31163 The Guix Build Coordinator package to use.
31165 @item @code{user} (default: @code{"guix-build-coordinator-agent"})
31166 The system user to run the service as.
31168 @item @code{coordinator} (default: @code{"http://localhost:8745"})
31169 The URI to use when connecting to the coordinator.
31171 @item @code{authentication}
31172 Record describing how this agent should authenticate with the
31173 coordinator. Possible record types are described below.
31175 @item @code{systems} (default: @code{#f})
31176 The systems for which this agent should fetch builds. The agent process
31177 will use the current system it's running on as the default.
31179 @item @code{max-parallel-builds} (default: @code{1})
31180 The number of builds to perform in parallel.
31182 @item @code{derivation-substitute-urls} (default: @code{#f})
31183 URLs from which to attempt to fetch substitutes for derivations, if the
31184 derivations aren't already available.
31186 @item @code{non-derivation-substitute-urls} (default: @code{#f})
31187 URLs from which to attempt to fetch substitutes for build inputs, if the
31188 input store items aren't already available.
31193 @deftp {Data Type} guix-build-coordinator-agent-password-auth
31194 Data type representing an agent authenticating with a coordinator via a
31199 The UUID of the agent. This should be generated by the coordinator
31200 process, stored in the coordinator database, and used by the intended
31203 @item @code{password}
31204 The password to use when connecting to the coordinator.
31209 @deftp {Data Type} guix-build-coordinator-agent-password-file-auth
31210 Data type representing an agent authenticating with a coordinator via a
31211 UUID and password read from a file.
31215 The UUID of the agent. This should be generated by the coordinator
31216 process, stored in the coordinator database, and used by the intended
31219 @item @code{password-file}
31220 A file containing the password to use when connecting to the
31226 @deftp {Data Type} guix-build-coordinator-agent-dynamic-auth
31227 Data type representing an agent authenticating with a coordinator via a
31228 dynamic auth token and agent name.
31231 @item @code{agent-name}
31232 Name of an agent, this is used to match up to an existing entry in the
31233 database if there is one. When no existing entry is found, a new entry
31234 is automatically added.
31237 Dynamic auth token, this is created and stored in the coordinator
31238 database, and is used by the agent to authenticate.
31243 @deftp {Data Type} guix-build-coordinator-agent-dynamic-auth-with-file
31244 Data type representing an agent authenticating with a coordinator via a
31245 dynamic auth token read from a file and agent name.
31248 @item @code{agent-name}
31249 Name of an agent, this is used to match up to an existing entry in the
31250 database if there is one. When no existing entry is found, a new entry
31251 is automatically added.
31253 @item @code{token-file}
31254 File containing the dynamic auth token, this is created and stored in
31255 the coordinator database, and is used by the agent to authenticate.
31260 The Guix Build Coordinator package contains a script to query an
31261 instance of the Guix Data Service for derivations to build, and then
31262 submit builds for those derivations to the coordinator. The service
31263 type below assists in running this script. This is an additional tool
31264 that may be useful when building derivations contained within an
31265 instance of the Guix Data Service.
31267 @defvar {Scheme Variable} guix-build-coordinator-queue-builds-service-type
31268 Service type for the
31269 guix-build-coordinator-queue-builds-from-guix-data-service script. Its
31270 value must be a @code{guix-build-coordinator-queue-builds-configuration}
31274 @deftp {Data Type} guix-build-coordinator-queue-builds-configuration
31275 Data type representing the options to the queue builds from guix data
31279 @item @code{package} (default: @code{guix-build-coordinator})
31280 The Guix Build Coordinator package to use.
31282 @item @code{user} (default: @code{"guix-build-coordinator-queue-builds"})
31283 The system user to run the service as.
31285 @item @code{coordinator} (default: @code{"http://localhost:8745"})
31286 The URI to use when connecting to the coordinator.
31288 @item @code{systems} (default: @code{#f})
31289 The systems for which to fetch derivations to build.
31291 @item @code{systems-and-targets} (default: @code{#f})
31292 An association list of system and target pairs for which to fetch
31293 derivations to build.
31295 @item @code{guix-data-service} (default: @code{"https://data.guix.gnu.org"})
31296 The Guix Data Service instance from which to query to find out about
31297 derivations to build.
31299 @item @code{processed-commits-file} (default: @code{"/var/cache/guix-build-coordinator-queue-builds/processed-commits"})
31300 A file to record which commits have been processed, to avoid needlessly
31301 processing them again if the service is restarted.
31306 @subsubheading Guix Data Service
31307 The @uref{http://data.guix.gnu.org,Guix Data Service} processes, stores
31308 and provides data about GNU Guix. This includes information about
31309 packages, derivations and lint warnings.
31311 The data is stored in a PostgreSQL database, and available through a web
31314 @defvar {Scheme Variable} guix-data-service-type
31315 Service type for the Guix Data Service. Its value must be a
31316 @code{guix-data-service-configuration} object. The service optionally
31317 extends the getmail service, as the guix-commits mailing list is used to
31318 find out about changes in the Guix git repository.
31321 @deftp {Data Type} guix-data-service-configuration
31322 Data type representing the configuration of the Guix Data Service.
31325 @item @code{package} (default: @code{guix-data-service})
31326 The Guix Data Service package to use.
31328 @item @code{user} (default: @code{"guix-data-service"})
31329 The system user to run the service as.
31331 @item @code{group} (default: @code{"guix-data-service"})
31332 The system group to run the service as.
31334 @item @code{port} (default: @code{8765})
31335 The port to bind the web service to.
31337 @item @code{host} (default: @code{"127.0.0.1"})
31338 The host to bind the web service to.
31340 @item @code{getmail-idle-mailboxes} (default: @code{#f})
31341 If set, this is the list of mailboxes that the getmail service will be
31342 configured to listen to.
31344 @item @code{commits-getmail-retriever-configuration} (default: @code{#f})
31345 If set, this is the @code{getmail-retriever-configuration} object with
31346 which to configure getmail to fetch mail from the guix-commits mailing
31349 @item @code{extra-options} (default: @var{'()})
31350 Extra command line options for @code{guix-data-service}.
31352 @item @code{extra-process-jobs-options} (default: @var{'()})
31353 Extra command line options for @code{guix-data-service-process-jobs}.
31358 @node Linux Services
31359 @subsection Linux Services
31362 @cindex out of memory killer
31364 @cindex early out of memory daemon
31365 @subsubheading Early OOM Service
31367 @uref{https://github.com/rfjakob/earlyoom,Early OOM}, also known as
31368 Earlyoom, is a minimalist out of memory (OOM) daemon that runs in user
31369 space and provides a more responsive and configurable alternative to the
31370 in-kernel OOM killer. It is useful to prevent the system from becoming
31371 unresponsive when it runs out of memory.
31373 @deffn {Scheme Variable} earlyoom-service-type
31374 The service type for running @command{earlyoom}, the Early OOM daemon.
31375 Its value must be a @code{earlyoom-configuration} object, described
31376 below. The service can be instantiated in its default configuration
31380 (service earlyoom-service-type)
31384 @deftp {Data Type} earlyoom-configuration
31385 This is the configuration record for the @code{earlyoom-service-type}.
31388 @item @code{earlyoom} (default: @var{earlyoom})
31389 The Earlyoom package to use.
31391 @item @code{minimum-available-memory} (default: @code{10})
31392 The threshold for the minimum @emph{available} memory, in percentages.
31394 @item @code{minimum-free-swap} (default: @code{10})
31395 The threshold for the minimum free swap memory, in percentages.
31397 @item @code{prefer-regexp} (default: @code{#f})
31398 A regular expression (as a string) to match the names of the processes
31399 that should be preferably killed.
31401 @item @code{avoid-regexp} (default: @code{#f})
31402 A regular expression (as a string) to match the names of the processes
31403 that should @emph{not} be killed.
31405 @item @code{memory-report-interval} (default: @code{0})
31406 The interval in seconds at which a memory report is printed. It is
31407 disabled by default.
31409 @item @code{ignore-positive-oom-score-adj?} (default: @code{#f})
31410 A boolean indicating whether the positive adjustments set in
31411 @file{/proc/*/oom_score_adj} should be ignored.
31413 @item @code{show-debug-messages?} (default: @code{#f})
31414 A boolean indicating whether debug messages should be printed. The logs
31415 are saved at @file{/var/log/earlyoom.log}.
31417 @item @code{send-notification-command} (default: @code{#f})
31418 This can be used to provide a custom command used for sending
31424 @cindex kernel module loader
31425 @subsubheading Kernel Module Loader Service
31427 The kernel module loader service allows one to load loadable kernel
31428 modules at boot. This is especially useful for modules that don't
31429 autoload and need to be manually loaded, as it's the case with
31432 @deffn {Scheme Variable} kernel-module-loader-service-type
31433 The service type for loading loadable kernel modules at boot with
31434 @command{modprobe}. Its value must be a list of strings representing
31435 module names. For example loading the drivers provided by
31436 @code{ddcci-driver-linux}, in debugging mode by passing some module
31437 parameters, can be done as follow:
31440 (use-modules (gnu) (gnu services))
31441 (use-package-modules linux)
31442 (use-service-modules linux)
31444 (define ddcci-config
31445 (plain-file "ddcci.conf"
31446 "options ddcci dyndbg delay=120"))
31450 (services (cons* (service kernel-module-loader-service-type
31451 '("ddcci" "ddcci_backlight"))
31452 (simple-service 'ddcci-config etc-service-type
31453 (list `("modprobe.d/ddcci.conf"
31456 (kernel-loadable-modules (list ddcci-driver-linux)))
31461 @cindex compressed swap
31462 @cindex Compressed RAM-based block devices
31463 @subsubheading Zram Device Service
31465 The Zram device service provides a compressed swap device in system
31466 memory. The Linux Kernel documentation has more information about
31467 @uref{https://www.kernel.org/doc/html/latest/admin-guide/blockdev/zram.html,zram}
31470 @deffn {Scheme Variable} zram-device-service-type
31471 This service creates the zram block device, formats it as swap and
31472 enables it as a swap device. The service's value is a
31473 @code{zram-device-configuration} record.
31475 @deftp {Data Type} zram-device-configuration
31476 This is the data type representing the configuration for the zram-device
31480 @item @code{size} (default @code{"1G"})
31481 This is the amount of space you wish to provide for the zram device. It
31482 accepts a string and can be a number of bytes or use a suffix, eg.:
31483 @code{"512M"} or @code{1024000}.
31484 @item @code{compression-algorithm} (default @code{'lzo})
31485 This is the compression algorithm you wish to use. It is difficult to
31486 list all the possible compression options, but common ones supported by
31487 Guix's Linux Libre Kernel include @code{'lzo}, @code{'lz4} and @code{'zstd}.
31488 @item @code{memory-limit} (default @code{0})
31489 This is the maximum amount of memory which the zram device can use.
31490 Setting it to '0' disables the limit. While it is generally expected
31491 that compression will be 2:1, it is possible that uncompressable data
31492 can be written to swap and this is a method to limit how much memory can
31493 be used. It accepts a string and can be a number of bytes or use a
31494 suffix, eg.: @code{"2G"}.
31495 @item @code{priority} (default @code{-1})
31496 This is the priority of the swap device created from the zram device.
31497 @code{swapon} accepts values between -1 and 32767, with higher values
31498 indicating higher priority. Higher priority swap will generally be used
31505 @node Hurd Services
31506 @subsection Hurd Services
31508 @defvr {Scheme Variable} hurd-console-service-type
31509 This service starts the fancy @code{VGA} console client on the Hurd.
31511 The service's value is a @code{hurd-console-configuration} record.
31514 @deftp {Data Type} hurd-console-configuration
31515 This is the data type representing the configuration for the
31516 hurd-console-service.
31519 @item @code{hurd} (default: @var{hurd})
31520 The Hurd package to use.
31524 @defvr {Scheme Variable} hurd-getty-service-type
31525 This service starts a tty using the Hurd @code{getty} program.
31527 The service's value is a @code{hurd-getty-configuration} record.
31530 @deftp {Data Type} hurd-getty-configuration
31531 This is the data type representing the configuration for the
31532 hurd-getty-service.
31535 @item @code{hurd} (default: @var{hurd})
31536 The Hurd package to use.
31539 The name of the console this Getty runs on---e.g., @code{"tty1"}.
31541 @item @code{baud-rate} (default: @code{38400})
31542 An integer specifying the baud rate of the tty.
31547 @node Miscellaneous Services
31548 @subsection Miscellaneous Services
31550 @cindex fingerprint
31551 @subsubheading Fingerprint Service
31553 The @code{(gnu services authentication)} module provides a DBus service to
31554 read and identify fingerprints via a fingerprint sensor.
31556 @defvr {Scheme Variable} fprintd-service-type
31557 The service type for @command{fprintd}, which provides the fingerprint
31558 reading capability.
31561 (service fprintd-service-type)
31566 @subsubheading System Control Service
31568 The @code{(gnu services sysctl)} provides a service to configure kernel
31569 parameters at boot.
31571 @defvr {Scheme Variable} sysctl-service-type
31572 The service type for @command{sysctl}, which modifies kernel parameters
31573 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
31577 (service sysctl-service-type
31578 (sysctl-configuration
31579 (settings '(("net.ipv4.ip_forward" . "1")))))
31582 Since @code{sysctl-service-type} is used in the default lists of
31583 services, @code{%base-services} and @code{%desktop-services}, you can
31584 use @code{modify-services} to change its configuration and add the
31585 kernel parameters that you want (@pxref{Service Reference,
31586 @code{modify-services}}).
31589 (modify-services %base-services
31590 (sysctl-service-type config =>
31591 (sysctl-configuration
31592 (settings (append '(("net.ipv4.ip_forward" . "1"))
31593 %default-sysctl-settings)))))
31598 @deftp {Data Type} sysctl-configuration
31599 The data type representing the configuration of @command{sysctl}.
31602 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
31603 The @command{sysctl} executable to use.
31605 @item @code{settings} (default: @code{%default-sysctl-settings})
31606 An association list specifies kernel parameters and their values.
31610 @defvr {Scheme Variable} %default-sysctl-settings
31611 An association list specifying the default @command{sysctl} parameters
31616 @subsubheading PC/SC Smart Card Daemon Service
31618 The @code{(gnu services security-token)} module provides the following service
31619 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
31620 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
31621 manager that coordinates communications with smart card readers, smart cards
31622 and cryptographic tokens that are connected to the system.
31624 @defvr {Scheme Variable} pcscd-service-type
31625 Service type for the @command{pcscd} service. Its value must be a
31626 @code{pcscd-configuration} object. To run pcscd in the default
31627 configuration, instantiate it as:
31630 (service pcscd-service-type)
31634 @deftp {Data Type} pcscd-configuration
31635 The data type representing the configuration of @command{pcscd}.
31638 @item @code{pcsc-lite} (default: @code{pcsc-lite})
31639 The pcsc-lite package that provides pcscd.
31640 @item @code{usb-drivers} (default: @code{(list ccid)})
31641 List of packages that provide USB drivers to pcscd. Drivers are expected to be
31642 under @file{pcsc/drivers} in the store directory of the package.
31647 @subsubheading Lirc Service
31649 The @code{(gnu services lirc)} module provides the following service.
31651 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
31652 [#:device #f] [#:driver #f] [#:config-file #f] @
31653 [#:extra-options '()]
31654 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
31655 decodes infrared signals from remote controls.
31657 Optionally, @var{device}, @var{driver} and @var{config-file}
31658 (configuration file name) may be specified. See @command{lircd} manual
31661 Finally, @var{extra-options} is a list of additional command-line options
31662 passed to @command{lircd}.
31666 @subsubheading Spice Service
31668 The @code{(gnu services spice)} module provides the following service.
31670 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
31671 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
31672 that enables sharing the clipboard with a vm and setting the guest display
31673 resolution when the graphical console window resizes.
31676 @cindex inputattach
31677 @subsubheading inputattach Service
31679 @cindex tablet input, for Xorg
31680 @cindex touchscreen input, for Xorg
31681 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
31682 use input devices such as Wacom tablets, touchscreens, or joysticks with the
31683 Xorg display server.
31685 @deffn {Scheme Variable} inputattach-service-type
31686 Type of a service that runs @command{inputattach} on a device and
31687 dispatches events from it.
31690 @deftp {Data Type} inputattach-configuration
31692 @item @code{device-type} (default: @code{"wacom"})
31693 The type of device to connect to. Run @command{inputattach --help}, from the
31694 @code{inputattach} package, to see the list of supported device types.
31696 @item @code{device} (default: @code{"/dev/ttyS0"})
31697 The device file to connect to the device.
31699 @item @code{baud-rate} (default: @code{#f})
31700 Baud rate to use for the serial connection.
31701 Should be a number or @code{#f}.
31703 @item @code{log-file} (default: @code{#f})
31704 If true, this must be the name of a file to log messages to.
31708 @subsubheading Dictionary Service
31710 The @code{(gnu services dict)} module provides the following service:
31712 @defvr {Scheme Variable} dicod-service-type
31713 This is the type of the service that runs the @command{dicod} daemon, an
31714 implementation of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
31717 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
31718 Return a service that runs the @command{dicod} daemon, an implementation
31719 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
31721 The optional @var{config} argument specifies the configuration for
31722 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
31723 default it serves the GNU Collaborative International Dictionary of English.
31725 You can add @command{open localhost} to your @file{~/.dico} file to make
31726 @code{localhost} the default server for @command{dico} client
31727 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
31730 @deftp {Data Type} dicod-configuration
31731 Data type representing the configuration of dicod.
31734 @item @code{dico} (default: @var{dico})
31735 Package object of the GNU Dico dictionary server.
31737 @item @code{interfaces} (default: @var{'("localhost")})
31738 This is the list of IP addresses and ports and possibly socket file
31739 names to listen to (@pxref{Server Settings, @code{listen} directive,,
31740 dico, GNU Dico Manual}).
31742 @item @code{handlers} (default: @var{'()})
31743 List of @code{<dicod-handler>} objects denoting handlers (module instances).
31745 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
31746 List of @code{<dicod-database>} objects denoting dictionaries to be served.
31750 @deftp {Data Type} dicod-handler
31751 Data type representing a dictionary handler (module instance).
31755 Name of the handler (module instance).
31757 @item @code{module} (default: @var{#f})
31758 Name of the dicod module of the handler (instance). If it is @code{#f},
31759 the module has the same name as the handler.
31760 (@pxref{Modules,,, dico, GNU Dico Manual}).
31762 @item @code{options}
31763 List of strings or gexps representing the arguments for the module handler
31767 @deftp {Data Type} dicod-database
31768 Data type representing a dictionary database.
31772 Name of the database, will be used in DICT commands.
31774 @item @code{handler}
31775 Name of the dicod handler (module instance) used by this database
31776 (@pxref{Handlers,,, dico, GNU Dico Manual}).
31778 @item @code{complex?} (default: @var{#f})
31779 Whether the database configuration complex. The complex configuration
31780 will need a corresponding @code{<dicod-handler>} object, otherwise not.
31782 @item @code{options}
31783 List of strings or gexps representing the arguments for the database
31784 (@pxref{Databases,,, dico, GNU Dico Manual}).
31788 @defvr {Scheme Variable} %dicod-database:gcide
31789 A @code{<dicod-database>} object serving the GNU Collaborative International
31790 Dictionary of English using the @code{gcide} package.
31793 The following is an example @code{dicod-service} configuration.
31796 (dicod-service #:config
31797 (dicod-configuration
31798 (handlers (list (dicod-handler
31802 (list #~(string-append "dbdir=" #$wordnet))))))
31803 (databases (list (dicod-database
31806 (handler "wordnet")
31807 (options '("database=wn")))
31808 %dicod-database:gcide))))
31812 @subsubheading Docker Service
31814 The @code{(gnu services docker)} module provides the following services.
31816 @defvr {Scheme Variable} docker-service-type
31818 This is the type of the service that runs @url{https://www.docker.com,Docker},
31819 a daemon that can execute application bundles (sometimes referred to as
31820 ``containers'') in isolated environments.
31824 @deftp {Data Type} docker-configuration
31825 This is the data type representing the configuration of Docker and Containerd.
31829 @item @code{package} (default: @code{docker})
31830 The Docker daemon package to use.
31832 @item @code{package} (default: @code{docker-cli})
31833 The Docker client package to use.
31835 @item @code{containerd} (default: @var{containerd})
31836 The Containerd package to use.
31838 @item @code{proxy} (default @var{docker-libnetwork-cmd-proxy})
31839 The Docker user-land networking proxy package to use.
31841 @item @code{enable-proxy?} (default @code{#t})
31842 Enable or disable the use of the Docker user-land networking proxy.
31844 @item @code{debug?} (default @code{#f})
31845 Enable or disable debug output.
31847 @item @code{enable-iptables?} (default @code{#t})
31848 Enable or disable the addition of iptables rules.
31853 @cindex Singularity, container service
31854 @defvr {Scheme Variable} singularity-service-type
31855 This is the type of the service that allows you to run
31856 @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
31857 create and run application bundles (aka. ``containers''). The value for this
31858 service is the Singularity package to use.
31860 The service does not install a daemon; instead, it installs helper programs as
31861 setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
31862 @command{singularity run} and similar commands.
31866 @subsubheading Auditd Service
31868 The @code{(gnu services auditd)} module provides the following service.
31870 @defvr {Scheme Variable} auditd-service-type
31872 This is the type of the service that runs
31873 @url{https://people.redhat.com/sgrubb/audit/,auditd},
31874 a daemon that tracks security-relevant information on your system.
31876 Examples of things that can be tracked:
31886 Failed login attempts
31893 @command{auditctl} from the @code{audit} package can be used in order
31894 to add or remove events to be tracked (until the next reboot).
31895 In order to permanently track events, put the command line arguments
31896 of auditctl into a file called @code{audit.rules} in the configuration
31897 directory (see below).
31898 @command{aureport} from the @code{audit} package can be used in order
31899 to view a report of all recorded events.
31900 The audit daemon by default logs into the file
31901 @file{/var/log/audit.log}.
31905 @deftp {Data Type} auditd-configuration
31906 This is the data type representing the configuration of auditd.
31910 @item @code{audit} (default: @code{audit})
31911 The audit package to use.
31913 @item @code{configuration-directory} (default: @code{%default-auditd-configuration-directory})
31914 The directory containing the configuration file for the audit package, which
31915 must be named @code{auditd.conf}, and optionally some audit rules to
31916 instantiate on startup.
31922 @subsubheading R-Shiny service
31924 The @code{(gnu services science)} module provides the following service.
31926 @defvr {Scheme Variable} rshiny-service-type
31928 This is a type of service which is used to run a webapp created with
31929 @code{r-shiny}. This service sets the @env{R_LIBS_USER} environment
31930 variable and runs the provided script to call @code{runApp}.
31932 @deftp {Data Type} rshiny-configuration
31933 This is the data type representing the configuration of rshiny.
31937 @item @code{package} (default: @code{r-shiny})
31938 The package to use.
31940 @item @code{binary} (defaunlt @code{"rshiny"})
31941 The name of the binary or shell script located at @code{package/bin/} to
31942 run when the service is run.
31944 The common way to create this file is as follows:
31948 (let* ((out (assoc-ref %outputs "out"))
31949 (targetdir (string-append out "/share/" ,name))
31950 (app (string-append out "/bin/" ,name))
31951 (Rbin (string-append (assoc-ref %build-inputs "r-min")
31954 (mkdir-p (string-append out "/bin"))
31955 (call-with-output-file app
31961 runApp(launch.browser=0, port=4202)~%\n"
31970 @subsubheading Nix service
31972 The @code{(gnu services nix)} module provides the following service.
31974 @defvr {Scheme Variable} nix-service-type
31976 This is the type of the service that runs build daemon of the
31977 @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
31981 (use-modules (gnu))
31982 (use-service-modules nix)
31983 (use-package-modules package-management)
31987 (packages (append (list nix)
31990 (services (append (list (service nix-service-type))
31994 After @command{guix system reconfigure} configure Nix for your user:
31997 @item Add a Nix channel and update it. See
31998 @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
32000 @item Create a symlink to your profile and activate Nix profile:
32004 $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
32005 $ source /run/current-system/profile/etc/profile.d/nix.sh
32010 @deftp {Data Type} nix-configuration
32011 This data type represents the configuration of the Nix daemon.
32014 @item @code{nix} (default: @code{nix})
32015 The Nix package to use.
32017 @item @code{sandbox} (default: @code{#t})
32018 Specifies whether builds are sandboxed by default.
32020 @item @code{build-sandbox-items} (default: @code{'()})
32021 This is a list of strings or objects appended to the
32022 @code{build-sandbox-items} field of the configuration file.
32024 @item @code{extra-config} (default: @code{'()})
32025 This is a list of strings or objects appended to the configuration file.
32026 It is used to pass extra text to be added verbatim to the configuration
32029 @item @code{extra-options} (default: @code{'()})
32030 Extra command line options for @code{nix-service-type}.
32034 @node Setuid Programs
32035 @section Setuid Programs
32037 @cindex setuid programs
32038 Some programs need to run with ``root'' privileges, even when they are
32039 launched by unprivileged users. A notorious example is the
32040 @command{passwd} program, which users can run to change their
32041 password, and which needs to access the @file{/etc/passwd} and
32042 @file{/etc/shadow} files---something normally restricted to root, for
32043 obvious security reasons. To address that, these executables are
32044 @dfn{setuid-root}, meaning that they always run with root privileges
32045 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
32046 for more info about the setuid mechanism).
32048 The store itself @emph{cannot} contain setuid programs: that would be a
32049 security issue since any user on the system can write derivations that
32050 populate the store (@pxref{The Store}). Thus, a different mechanism is
32051 used: instead of changing the setuid bit directly on files that are in
32052 the store, we let the system administrator @emph{declare} which programs
32053 should be setuid root.
32055 The @code{setuid-programs} field of an @code{operating-system}
32056 declaration contains a list of G-expressions denoting the names of
32057 programs to be setuid-root (@pxref{Using the Configuration System}).
32058 For instance, the @command{passwd} program, which is part of the Shadow
32059 package, can be designated by this G-expression (@pxref{G-Expressions}):
32062 #~(string-append #$shadow "/bin/passwd")
32065 A default set of setuid programs is defined by the
32066 @code{%setuid-programs} variable of the @code{(gnu system)} module.
32068 @defvr {Scheme Variable} %setuid-programs
32069 A list of G-expressions denoting common programs that are setuid-root.
32071 The list includes commands such as @command{passwd}, @command{ping},
32072 @command{su}, and @command{sudo}.
32075 Under the hood, the actual setuid programs are created in the
32076 @file{/run/setuid-programs} directory at system activation time. The
32077 files in this directory refer to the ``real'' binaries, which are in the
32080 @node X.509 Certificates
32081 @section X.509 Certificates
32083 @cindex HTTPS, certificates
32084 @cindex X.509 certificates
32086 Web servers available over HTTPS (that is, HTTP over the transport-layer
32087 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
32088 that the client can then use to @emph{authenticate} the server. To do
32089 that, clients verify that the server's certificate is signed by a
32090 so-called @dfn{certificate authority} (CA). But to verify the CA's
32091 signature, clients must have first acquired the CA's certificate.
32093 Web browsers such as GNU@tie{}IceCat include their own set of CA
32094 certificates, such that they are able to verify CA signatures
32097 However, most other programs that can talk HTTPS---@command{wget},
32098 @command{git}, @command{w3m}, etc.---need to be told where CA
32099 certificates can be found.
32101 @cindex @code{nss-certs}
32102 In Guix, this is done by adding a package that provides certificates
32103 to the @code{packages} field of the @code{operating-system} declaration
32104 (@pxref{operating-system Reference}). Guix includes one such package,
32105 @code{nss-certs}, which is a set of CA certificates provided as part of
32106 Mozilla's Network Security Services.
32108 Note that it is @emph{not} part of @code{%base-packages}, so you need to
32109 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
32110 most applications and libraries look for certificates by default, points
32111 to the certificates installed globally.
32113 Unprivileged users, including users of Guix on a foreign distro,
32114 can also install their own certificate package in
32115 their profile. A number of environment variables need to be defined so
32116 that applications and libraries know where to find them. Namely, the
32117 OpenSSL library honors the @env{SSL_CERT_DIR} and @env{SSL_CERT_FILE}
32118 variables. Some applications add their own environment variables; for
32119 instance, the Git version control system honors the certificate bundle
32120 pointed to by the @env{GIT_SSL_CAINFO} environment variable. Thus, you
32121 would typically run something like:
32124 guix install nss-certs
32125 export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
32126 export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
32127 export GIT_SSL_CAINFO="$SSL_CERT_FILE"
32130 As another example, R requires the @env{CURL_CA_BUNDLE} environment
32131 variable to point to a certificate bundle, so you would have to run
32132 something like this:
32135 guix install nss-certs
32136 export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
32139 For other applications you may want to look up the required environment
32140 variable in the relevant documentation.
32143 @node Name Service Switch
32144 @section Name Service Switch
32146 @cindex name service switch
32148 The @code{(gnu system nss)} module provides bindings to the
32149 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
32150 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
32151 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
32152 extended with new ``name'' lookup methods for system databases, which
32153 includes host names, service names, user accounts, and more (@pxref{Name
32154 Service Switch, System Databases and Name Service Switch,, libc, The GNU
32155 C Library Reference Manual}).
32157 The NSS configuration specifies, for each system database, which lookup
32158 method is to be used, and how the various methods are chained
32159 together---for instance, under which circumstances NSS should try the
32160 next method in the list. The NSS configuration is given in the
32161 @code{name-service-switch} field of @code{operating-system} declarations
32162 (@pxref{operating-system Reference, @code{name-service-switch}}).
32165 @cindex .local, host name lookup
32166 As an example, the declaration below configures the NSS to use the
32167 @uref{https://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
32168 back-end}, which supports host name lookups over multicast DNS (mDNS)
32169 for host names ending in @code{.local}:
32172 (name-service-switch
32173 (hosts (list %files ;first, check /etc/hosts
32175 ;; If the above did not succeed, try
32176 ;; with 'mdns_minimal'.
32178 (name "mdns_minimal")
32180 ;; 'mdns_minimal' is authoritative for
32181 ;; '.local'. When it returns "not found",
32182 ;; no need to try the next methods.
32183 (reaction (lookup-specification
32184 (not-found => return))))
32186 ;; Then fall back to DNS.
32190 ;; Finally, try with the "full" 'mdns'.
32195 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
32196 contains this configuration, so you will not have to type it if all you
32197 want is to have @code{.local} host lookup working.
32199 Note that, in this case, in addition to setting the
32200 @code{name-service-switch} of the @code{operating-system} declaration,
32201 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
32202 @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
32203 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
32204 to the name service cache daemon (@pxref{Base Services,
32205 @code{nscd-service}}).
32207 For convenience, the following variables provide typical NSS
32210 @defvr {Scheme Variable} %default-nss
32211 This is the default name service switch configuration, a
32212 @code{name-service-switch} object.
32215 @defvr {Scheme Variable} %mdns-host-lookup-nss
32216 This is the name service switch configuration with support for host name
32217 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
32220 The reference for name service switch configuration is given below. It
32221 is a direct mapping of the configuration file format of the C library , so
32222 please refer to the C library manual for more information (@pxref{NSS
32223 Configuration File,,, libc, The GNU C Library Reference Manual}).
32224 Compared to the configuration file format of libc NSS, it has the advantage
32225 not only of adding this warm parenthetic feel that we like, but also
32226 static checks: you will know about syntax errors and typos as soon as you
32227 run @command{guix system}.
32229 @deftp {Data Type} name-service-switch
32231 This is the data type representation the configuration of libc's name
32232 service switch (NSS). Each field below represents one of the supported
32249 The system databases handled by the NSS@. Each of these fields must be a
32250 list of @code{<name-service>} objects (see below).
32254 @deftp {Data Type} name-service
32256 This is the data type representing an actual name service and the
32257 associated lookup action.
32261 A string denoting the name service (@pxref{Services in the NSS
32262 configuration,,, libc, The GNU C Library Reference Manual}).
32264 Note that name services listed here must be visible to nscd. This is
32265 achieved by passing the @code{#:name-services} argument to
32266 @code{nscd-service} the list of packages providing the needed name
32267 services (@pxref{Base Services, @code{nscd-service}}).
32270 An action specified using the @code{lookup-specification} macro
32271 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
32272 Reference Manual}). For example:
32275 (lookup-specification (unavailable => continue)
32276 (success => return))
32281 @node Initial RAM Disk
32282 @section Initial RAM Disk
32285 @cindex initial RAM disk
32286 For bootstrapping purposes, the Linux-Libre kernel is passed an
32287 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
32288 root file system as well as an initialization script. The latter is
32289 responsible for mounting the real root file system, and for loading any
32290 kernel modules that may be needed to achieve that.
32292 The @code{initrd-modules} field of an @code{operating-system}
32293 declaration allows you to specify Linux-libre kernel modules that must
32294 be available in the initrd. In particular, this is where you would list
32295 modules needed to actually drive the hard disk where your root partition
32296 is---although the default value of @code{initrd-modules} should cover
32297 most use cases. For example, assuming you need the @code{megaraid_sas}
32298 module in addition to the default modules to be able to access your root
32299 file system, you would write:
32304 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
32307 @defvr {Scheme Variable} %base-initrd-modules
32308 This is the list of kernel modules included in the initrd by default.
32311 Furthermore, if you need lower-level customization, the @code{initrd}
32312 field of an @code{operating-system} declaration allows
32313 you to specify which initrd you would like to use. The @code{(gnu
32314 system linux-initrd)} module provides three ways to build an initrd: the
32315 high-level @code{base-initrd} procedure and the low-level
32316 @code{raw-initrd} and @code{expression->initrd} procedures.
32318 The @code{base-initrd} procedure is intended to cover most common uses.
32319 For example, if you want to add a bunch of kernel modules to be loaded
32320 at boot time, you can define the @code{initrd} field of the operating
32321 system declaration like this:
32324 (initrd (lambda (file-systems . rest)
32325 ;; Create a standard initrd but set up networking
32326 ;; with the parameters QEMU expects by default.
32327 (apply base-initrd file-systems
32328 #:qemu-networking? #t
32332 The @code{base-initrd} procedure also handles common use cases that
32333 involves using the system as a QEMU guest, or as a ``live'' system with
32334 volatile root file system.
32336 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
32337 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
32338 such as trying to guess which kernel modules and packages should be included
32339 to the initrd. An example use of @code{raw-initrd} is when a user has
32340 a custom Linux kernel configuration and default kernel modules included by
32341 @code{base-initrd} are not available.
32343 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
32344 honors several options passed on the Linux kernel command line
32345 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
32346 @code{-append} option of QEMU), notably:
32349 @item --load=@var{boot}
32350 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
32351 program, once it has mounted the root file system.
32353 Guix uses this option to yield control to a boot program that runs the
32354 service activation programs and then spawns the GNU@tie{}Shepherd, the
32355 initialization system.
32357 @item --root=@var{root}
32358 Mount @var{root} as the root file system. @var{root} can be a device
32359 name like @code{/dev/sda1}, a file system label, or a file system UUID.
32360 When unspecified, the device name from the root file system of the
32361 operating system declaration is used.
32363 @item --system=@var{system}
32364 Have @file{/run/booted-system} and @file{/run/current-system} point to
32367 @item modprobe.blacklist=@var{modules}@dots{}
32368 @cindex module, black-listing
32369 @cindex black list, of kernel modules
32370 Instruct the initial RAM disk as well as the @command{modprobe} command
32371 (from the kmod package) to refuse to load @var{modules}. @var{modules}
32372 must be a comma-separated list of module names---e.g.,
32373 @code{usbkbd,9pnet}.
32376 Start a read-eval-print loop (REPL) from the initial RAM disk before it
32377 tries to load kernel modules and to mount the root file system. Our
32378 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
32379 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
32380 Manual}, for more information on Guile's REPL.
32384 Now that you know all the features that initial RAM disks produced by
32385 @code{base-initrd} and @code{raw-initrd} provide,
32386 here is how to use it and customize it further.
32389 @cindex initial RAM disk
32390 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
32391 [#:linux-modules '()] [#:mapped-devices '()] @
32392 [#:keyboard-layout #f] @
32393 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
32394 Return a derivation that builds a raw initrd. @var{file-systems} is
32395 a list of file systems to be mounted by the initrd, possibly in addition to
32396 the root file system specified on the kernel command line via @option{--root}.
32397 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
32398 @var{mapped-devices} is a list of device mappings to realize before
32399 @var{file-systems} are mounted (@pxref{Mapped Devices}).
32400 @var{helper-packages} is a list of packages to be copied in the initrd.
32402 include @code{e2fsck/static} or other packages needed by the initrd to check
32403 the root file system.
32405 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
32406 the desired console keyboard layout. This is done before @var{mapped-devices}
32407 are set up and before @var{file-systems} are mounted such that, should the
32408 user need to enter a passphrase or use the REPL, this happens using the
32409 intended keyboard layout.
32411 When @var{qemu-networking?} is true, set up networking with the standard QEMU
32412 parameters. When @var{virtio?} is true, load additional modules so that the
32413 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
32415 When @var{volatile-root?} is true, the root file system is writable but any changes
32419 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
32420 [#:mapped-devices '()] [#:keyboard-layout #f] @
32421 [#:qemu-networking? #f] [#:volatile-root? #f] @
32422 [#:linux-modules '()]
32423 Return as a file-like object a generic initrd, with kernel
32424 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
32425 mounted by the initrd, possibly in addition to the root file system specified
32426 on the kernel command line via @option{--root}. @var{mapped-devices} is a list of device
32427 mappings to realize before @var{file-systems} are mounted.
32429 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
32430 the desired console keyboard layout. This is done before @var{mapped-devices}
32431 are set up and before @var{file-systems} are mounted such that, should the
32432 user need to enter a passphrase or use the REPL, this happens using the
32433 intended keyboard layout.
32435 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
32437 The initrd is automatically populated with all the kernel modules necessary
32438 for @var{file-systems} and for the given options. Additional kernel
32439 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
32440 loaded at boot time in the order in which they appear.
32443 Needless to say, the initrds we produce and use embed a
32444 statically-linked Guile, and the initialization program is a Guile
32445 program. That gives a lot of flexibility. The
32446 @code{expression->initrd} procedure builds such an initrd, given the
32447 program to run in that initrd.
32449 @deffn {Scheme Procedure} expression->initrd @var{exp} @
32450 [#:guile %guile-3.0-static-stripped] [#:name "guile-initrd"]
32451 Return as a file-like object a Linux initrd (a gzipped cpio archive)
32452 containing @var{guile} and that evaluates @var{exp}, a G-expression,
32453 upon booting. All the derivations referenced by @var{exp} are
32454 automatically copied to the initrd.
32457 @node Bootloader Configuration
32458 @section Bootloader Configuration
32461 @cindex boot loader
32463 The operating system supports multiple bootloaders. The bootloader is
32464 configured using @code{bootloader-configuration} declaration. All the
32465 fields of this structure are bootloader agnostic except for one field,
32466 @code{bootloader} that indicates the bootloader to be configured and
32469 Some of the bootloaders do not honor every field of
32470 @code{bootloader-configuration}. For instance, the extlinux
32471 bootloader does not support themes and thus ignores the @code{theme}
32474 @deftp {Data Type} bootloader-configuration
32475 The type of a bootloader configuration declaration.
32479 @item @code{bootloader}
32480 @cindex EFI, bootloader
32481 @cindex UEFI, bootloader
32482 @cindex BIOS, bootloader
32483 The bootloader to use, as a @code{bootloader} object. For now
32484 @code{grub-bootloader}, @code{grub-efi-bootloader},
32485 @code{grub-efi-netboot-bootloader}, @code{extlinux-bootloader} and
32486 @code{u-boot-bootloader} are supported.
32488 @cindex ARM, bootloaders
32489 @cindex AArch64, bootloaders
32490 Available bootloaders are described in @code{(gnu bootloader @dots{})}
32491 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
32492 of bootloaders for a wide range of ARM and AArch64 systems, using the
32493 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
32495 @vindex grub-efi-bootloader
32496 @code{grub-efi-bootloader} allows to boot on modern systems using the
32497 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
32498 use if the installation image contains a @file{/sys/firmware/efi} directory
32499 when you boot it on your system.
32501 @vindex grub-bootloader
32502 @code{grub-bootloader} allows you to boot in particular Intel-based machines
32503 in ``legacy'' BIOS mode.
32505 @vindex grub-efi-netboot-bootloader
32506 @code{grub-efi-netboot-bootloader} allows you to boot your system over network
32507 through TFTP@. In combination with an NFS root file system this allows you to
32508 build a diskless Guix system.
32510 The installation of the @code{grub-efi-netboot-bootloader} generates the content
32511 of the TFTP root directory at @code{target}
32512 (@pxref{Bootloader Configuration, @code{target}}), to be served by a TFTP server.
32513 You may want to mount your TFTP server directory onto @code{target} to move the
32514 required files to the TFTP server automatically.
32516 If you plan to use an NFS root file system as well (actually if you mount the
32517 store from an NFS share), then the TFTP server needs to serve the file
32518 @file{/boot/grub/grub.cfg} and other files from the store (like GRUBs background
32519 image, the kernel (@pxref{operating-system Reference, @code{kernel}}) and the
32520 initrd (@pxref{operating-system Reference, @code{initrd}})), too. All these
32521 files from the store will be accessed by GRUB through TFTP with their normal
32522 store path, for example as
32523 @file{tftp://tftp-server/gnu/store/…-initrd/initrd.cpio.gz}.
32525 Two symlinks are created to make this possible. The first symlink is
32526 @code{target}@file{/efi/Guix/boot/grub/grub.cfg} pointing to
32527 @file{../../../boot/grub/grub.cfg},
32528 where @code{target} may be @file{/boot}. In this case the link is not leaving
32529 the served TFTP root directory, but otherwise it does. The second link is
32530 @code{target}@file{/gnu/store} and points to @file{../gnu/store}. This link
32531 is leaving the served TFTP root directory.
32533 The assumption behind all this is that you have an NFS server exporting the root
32534 file system for your Guix system, and additionally a TFTP server exporting your
32535 @code{target} directory—usually @file{/boot}—from that same root file system for
32536 your Guix system. In this constellation the symlinks will work.
32538 For other constellations you will have to program your own bootloader installer,
32539 which then takes care to make necessary files from the store accessible through
32540 TFTP, for example by copying them into the TFTP root directory at @code{target}.
32542 It is important to note that symlinks pointing outside the TFTP root directory
32543 may need to be allowed in the configuration of your TFTP server. Further the
32544 store link exposes the whole store through TFTP@. Both points need to be
32545 considered carefully for security aspects.
32547 Beside the @code{grub-efi-netboot-bootloader}, the already mentioned TFTP and
32548 NFS servers, you also need a properly configured DHCP server to make the booting
32549 over netboot possible. For all this we can currently only recommend you to look
32550 for instructions about @acronym{PXE, Preboot eXecution Environment}.
32552 @item @code{target}
32553 This is a string denoting the target onto which to install the
32556 The interpretation depends on the bootloader in question. For
32557 @code{grub-bootloader}, for example, it should be a device name understood by
32558 the bootloader @command{installer} command, such as @code{/dev/sda} or
32559 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
32560 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
32561 system, usually @file{/boot/efi}. For @code{grub-efi-netboot-bootloader},
32562 @code{target} should be the mount point corresponding to the TFTP root
32563 directory of your TFTP server.
32565 @item @code{menu-entries} (default: @code{()})
32566 A possibly empty list of @code{menu-entry} objects (see below), denoting
32567 entries to appear in the bootloader menu, in addition to the current
32568 system entry and the entry pointing to previous system generations.
32570 @item @code{default-entry} (default: @code{0})
32571 The index of the default boot menu entry. Index 0 is for the entry of the
32574 @item @code{timeout} (default: @code{5})
32575 The number of seconds to wait for keyboard input before booting. Set to
32576 0 to boot immediately, and to -1 to wait indefinitely.
32578 @cindex keyboard layout, for the bootloader
32579 @item @code{keyboard-layout} (default: @code{#f})
32580 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
32581 layout, usually US@tie{}English (``qwerty'').
32583 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
32587 This option is currently ignored by bootloaders other than @code{grub} and
32591 @item @code{theme} (default: @var{#f})
32592 The bootloader theme object describing the theme to use. If no theme
32593 is provided, some bootloaders might use a default theme, that's true
32596 @item @code{terminal-outputs} (default: @code{'(gfxterm)})
32597 The output terminals used for the bootloader boot menu, as a list of
32598 symbols. GRUB accepts the values: @code{console}, @code{serial},
32599 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
32600 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
32601 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
32602 configuration,,, grub,GNU GRUB manual}).
32604 @item @code{terminal-inputs} (default: @code{'()})
32605 The input terminals used for the bootloader boot menu, as a list of
32606 symbols. For GRUB, the default is the native platform terminal as
32607 determined at run-time. GRUB accepts the values: @code{console},
32608 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
32609 @code{usb_keyboard}. This field corresponds to the GRUB variable
32610 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
32613 @item @code{serial-unit} (default: @code{#f})
32614 The serial unit used by the bootloader, as an integer from 0 to 3.
32615 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
32616 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
32618 @item @code{serial-speed} (default: @code{#f})
32619 The speed of the serial interface, as an integer. For GRUB, the
32620 default value is chosen at run-time; currently GRUB chooses
32621 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
32628 Should you want to list additional boot menu entries @i{via} the
32629 @code{menu-entries} field above, you will need to create them with the
32630 @code{menu-entry} form. For example, imagine you want to be able to
32631 boot another distro (hard to imagine!), you can define a menu entry
32636 (label "The Other Distro")
32637 (linux "/boot/old/vmlinux-2.6.32")
32638 (linux-arguments '("root=/dev/sda2"))
32639 (initrd "/boot/old/initrd"))
32644 @deftp {Data Type} menu-entry
32645 The type of an entry in the bootloader menu.
32650 The label to show in the menu---e.g., @code{"GNU"}.
32652 @item @code{linux} (default: @code{#f})
32653 The Linux kernel image to boot, for example:
32656 (file-append linux-libre "/bzImage")
32659 For GRUB, it is also possible to specify a device explicitly in the
32660 file path using GRUB's device naming convention (@pxref{Naming
32661 convention,,, grub, GNU GRUB manual}), for example:
32664 "(hd0,msdos1)/boot/vmlinuz"
32667 If the device is specified explicitly as above, then the @code{device}
32668 field is ignored entirely.
32670 @item @code{linux-arguments} (default: @code{()})
32671 The list of extra Linux kernel command-line arguments---e.g.,
32672 @code{("console=ttyS0")}.
32674 @item @code{initrd} (default: @code{#f})
32675 A G-Expression or string denoting the file name of the initial RAM disk
32676 to use (@pxref{G-Expressions}).
32678 @item @code{device} (default: @code{#f})
32679 The device where the kernel and initrd are to be found---i.e., for GRUB,
32680 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
32682 This may be a file system label (a string), a file system UUID (a
32683 bytevector, @pxref{File Systems}), or @code{#f}, in which case
32684 the bootloader will search the device containing the file specified by
32685 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
32686 must @emph{not} be an OS device name such as @file{/dev/sda1}.
32688 @item @code{multiboot-kernel} (default: @code{#f})
32689 The kernel to boot in Multiboot-mode (@pxref{multiboot,,, grub, GNU GRUB
32690 manual}). When this field is set, a Multiboot menu-entry is generated.
32694 (file-append mach "/boot/gnumach")
32697 @item @code{multiboot-arguments} (default: @code{()})
32698 The list of extra command-line arguments for the multiboot-kernel.
32700 @item @code{multiboot-modules} (default: @code{()})
32701 The list of commands for loading Multiboot modules. For example:
32704 (list (list (file-append hurd "/hurd/ext2fs.static") "ext2fs"
32706 (list (file-append libc "/lib/ld.so.1") "exec"
32716 @c FIXME: Write documentation once it's stable.
32717 For now only GRUB has theme support. GRUB themes are created using
32718 the @code{grub-theme} form, which is not fully documented yet.
32720 @deftp {Data Type} grub-theme
32721 Data type representing the configuration of the GRUB theme.
32724 @item @code{gfxmode} (default: @code{'("auto")})
32725 The GRUB @code{gfxmode} to set (a list of screen resolution strings,
32726 @pxref{gfxmode,,, grub, GNU GRUB manual}).
32730 @deffn {Scheme Procedure} grub-theme
32731 Return the default GRUB theme used by the operating system if no
32732 @code{theme} field is specified in @code{bootloader-configuration}
32735 It comes with a fancy background image displaying the GNU and Guix
32739 For example, to override the default resolution, you may use something
32744 (bootloader-configuration
32747 (inherit (grub-theme))
32748 (gfxmode '("1024x786x32" "auto"))))))
32751 @node Invoking guix system
32752 @section Invoking @code{guix system}
32754 Once you have written an operating system declaration as seen in the
32755 previous section, it can be @dfn{instantiated} using the @command{guix
32756 system} command. The synopsis is:
32759 guix system @var{options}@dots{} @var{action} @var{file}
32762 @var{file} must be the name of a file containing an
32763 @code{operating-system} declaration. @var{action} specifies how the
32764 operating system is instantiated. Currently the following values are
32769 Display available service type definitions that match the given regular
32770 expressions, sorted by relevance:
32776 $ guix system search console
32777 name: console-fonts
32778 location: gnu/services/base.scm:806:2
32779 extends: shepherd-root
32780 description: Install the given fonts on the specified ttys (fonts are per
32781 + virtual console on GNU/Linux). The value of this service is a list of
32782 + tty/font pairs. The font can be the name of a font provided by the `kbd'
32783 + package or any valid argument to `setfont', as in this example:
32785 + '(("tty1" . "LatGrkCyr-8x16")
32786 + ("tty2" . (file-append
32788 + "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
32789 + ("tty3" . (file-append
32791 + "/share/consolefonts/ter-132n"))) ; for HDPI
32795 location: gnu/services/base.scm:1190:2
32796 extends: shepherd-root
32797 description: Provide console login using the `mingetty' program.
32801 location: gnu/services/base.scm:860:2
32803 description: Provide a console log-in service as specified by its
32804 + configuration value, a `login-configuration' object.
32810 As for @command{guix package --search}, the result is written in
32811 @code{recutils} format, which makes it easy to filter the output
32812 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
32815 Build the operating system described in @var{file}, activate it, and
32816 switch to it@footnote{This action (and the related actions
32817 @code{switch-generation} and @code{roll-back}) are usable only on
32818 systems already running Guix System.}.
32821 @c The paragraph below refers to the problem discussed at
32822 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
32823 It is highly recommended to run @command{guix pull} once before you run
32824 @command{guix system reconfigure} for the first time (@pxref{Invoking
32825 guix pull}). Failing to do that you would see an older version of Guix
32826 once @command{reconfigure} has completed.
32829 This effects all the configuration specified in @var{file}: user
32830 accounts, system services, global package list, setuid programs, etc.
32831 The command starts system services specified in @var{file} that are not
32832 currently running; if a service is currently running this command will
32833 arrange for it to be upgraded the next time it is stopped (e.g.@: by
32834 @code{herd stop X} or @code{herd restart X}).
32836 This command creates a new generation whose number is one greater than
32837 the current generation (as reported by @command{guix system
32838 list-generations}). If that generation already exists, it will be
32839 overwritten. This behavior mirrors that of @command{guix package}
32840 (@pxref{Invoking guix package}).
32842 It also adds a bootloader menu entry for the new OS configuration,
32843 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
32844 entries for older configurations to a submenu, allowing you to choose
32845 an older system generation at boot time should you need it.
32847 @cindex provenance tracking, of the operating system
32848 Upon completion, the new system is deployed under
32849 @file{/run/current-system}. This directory contains @dfn{provenance
32850 meta-data}: the list of channels in use (@pxref{Channels}) and
32851 @var{file} itself, when available. You can view it by running:
32854 guix system describe
32857 This information is useful should you later want to inspect how this
32858 particular generation was built. In fact, assuming @var{file} is
32859 self-contained, you can later rebuild generation @var{n} of your
32860 operating system with:
32863 guix time-machine \
32864 -C /var/guix/profiles/system-@var{n}-link/channels.scm -- \
32865 system reconfigure \
32866 /var/guix/profiles/system-@var{n}-link/configuration.scm
32869 You can think of it as some sort of built-in version control! Your
32870 system is not just a binary artifact: @emph{it carries its own source}.
32871 @xref{Service Reference, @code{provenance-service-type}}, for more
32872 information on provenance tracking.
32874 By default, @command{reconfigure} @emph{prevents you from downgrading
32875 your system}, which could (re)introduce security vulnerabilities and
32876 also cause problems with ``stateful'' services such as database
32877 management systems. You can override that behavior by passing
32878 @option{--allow-downgrades}.
32880 @item switch-generation
32881 @cindex generations
32882 Switch to an existing system generation. This action atomically
32883 switches the system profile to the specified system generation. It
32884 also rearranges the system's existing bootloader menu entries. It
32885 makes the menu entry for the specified system generation the default,
32886 and it moves the entries for the other generations to a submenu, if
32887 supported by the bootloader being used. The next time the system
32888 boots, it will use the specified system generation.
32890 The bootloader itself is not being reinstalled when using this
32891 command. Thus, the installed bootloader is used with an updated
32892 configuration file.
32894 The target generation can be specified explicitly by its generation
32895 number. For example, the following invocation would switch to system
32899 guix system switch-generation 7
32902 The target generation can also be specified relative to the current
32903 generation with the form @code{+N} or @code{-N}, where @code{+3} means
32904 ``3 generations ahead of the current generation,'' and @code{-1} means
32905 ``1 generation prior to the current generation.'' When specifying a
32906 negative value such as @code{-1}, you must precede it with @code{--} to
32907 prevent it from being parsed as an option. For example:
32910 guix system switch-generation -- -1
32913 Currently, the effect of invoking this action is @emph{only} to switch
32914 the system profile to an existing generation and rearrange the
32915 bootloader menu entries. To actually start using the target system
32916 generation, you must reboot after running this action. In the future,
32917 it will be updated to do the same things as @command{reconfigure},
32918 like activating and deactivating services.
32920 This action will fail if the specified generation does not exist.
32923 @cindex rolling back
32924 Switch to the preceding system generation. The next time the system
32925 boots, it will use the preceding system generation. This is the inverse
32926 of @command{reconfigure}, and it is exactly the same as invoking
32927 @command{switch-generation} with an argument of @code{-1}.
32929 Currently, as with @command{switch-generation}, you must reboot after
32930 running this action to actually start using the preceding system
32933 @item delete-generations
32934 @cindex deleting system generations
32935 @cindex saving space
32936 Delete system generations, making them candidates for garbage collection
32937 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
32940 This works in the same way as @samp{guix package --delete-generations}
32941 (@pxref{Invoking guix package, @option{--delete-generations}}). With no
32942 arguments, all system generations but the current one are deleted:
32945 guix system delete-generations
32948 You can also select the generations you want to delete. The example below
32949 deletes all the system generations that are more than two month old:
32952 guix system delete-generations 2m
32955 Running this command automatically reinstalls the bootloader with an updated
32956 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
32957 longer lists the generations that have been deleted.
32960 Build the derivation of the operating system, which includes all the
32961 configuration files and programs needed to boot and run the system.
32962 This action does not actually install anything.
32965 Populate the given directory with all the files necessary to run the
32966 operating system specified in @var{file}. This is useful for first-time
32967 installations of Guix System. For instance:
32970 guix system init my-os-config.scm /mnt
32973 copies to @file{/mnt} all the store items required by the configuration
32974 specified in @file{my-os-config.scm}. This includes configuration
32975 files, packages, and so on. It also creates other essential files
32976 needed for the system to operate correctly---e.g., the @file{/etc},
32977 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
32979 This command also installs bootloader on the target specified in
32980 @file{my-os-config}, unless the @option{--no-bootloader} option was
32984 @cindex virtual machine
32986 @anchor{guix system vm}
32987 Build a virtual machine that contains the operating system declared in
32988 @var{file}, and return a script to run that virtual machine (VM).
32991 The @code{vm} action and others below
32992 can use KVM support in the Linux-libre kernel. Specifically, if the
32993 machine has hardware virtualization support, the corresponding
32994 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
32995 must exist and be readable and writable by the user and by the
32996 build users of the daemon (@pxref{Build Environment Setup}).
32999 Arguments given to the script are passed to QEMU as in the example
33000 below, which enables networking and requests 1@tie{}GiB of RAM for the
33004 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -smp 2 -net user,model=virtio-net-pci
33007 The VM shares its store with the host system.
33009 Additional file systems can be shared between the host and the VM using
33010 the @option{--share} and @option{--expose} command-line options: the former
33011 specifies a directory to be shared with write access, while the latter
33012 provides read-only access to the shared directory.
33014 The example below creates a VM in which the user's home directory is
33015 accessible read-only, and where the @file{/exchange} directory is a
33016 read-write mapping of @file{$HOME/tmp} on the host:
33019 guix system vm my-config.scm \
33020 --expose=$HOME --share=$HOME/tmp=/exchange
33023 On GNU/Linux, the default is to boot directly to the kernel; this has
33024 the advantage of requiring only a very tiny root disk image since the
33025 store of the host can then be mounted.
33027 The @option{--full-boot} option forces a complete boot sequence, starting
33028 with the bootloader. This requires more disk space since a root image
33029 containing at least the kernel, initrd, and bootloader data files must
33030 be created. The @option{--image-size} option can be used to specify the
33033 @cindex System images, creation in various formats
33034 @cindex Creating system images in various formats
33036 @itemx docker-image
33037 Return a virtual machine, disk image, or Docker image of the operating
33038 system declared in @var{file} that stands alone. By default,
33039 @command{guix system} estimates the size of the image needed to store
33040 the system, but you can use the @option{--image-size} option to specify
33041 a value. Docker images are built to contain exactly what they need, so
33042 the @option{--image-size} option is ignored in the case of
33043 @code{docker-image}.
33045 @cindex image, creating disk images
33046 The @code{image} command can produce various image types. The
33047 image type can be selected using the @option{--image-type} option. It
33048 defaults to @code{efi-raw}. When its value is @code{iso9660}, the
33049 @option{--label} option can be used to specify a volume ID with
33050 @code{image}. By default, the root file system of a disk image is
33051 mounted non-volatile; the @option{--volatile} option can be provided to
33052 make it volatile instead. When using @code{image}, the bootloader
33053 installed on the generated image is taken from the provided
33054 @code{operating-system} definition. The following example demonstrates
33055 how to generate an image that uses the @code{grub-efi-bootloader}
33056 bootloader and boot it with QEMU:
33059 image=$(guix system image --image-type=qcow2 \
33060 gnu/system/examples/lightweight-desktop.tmpl)
33061 cp $image /tmp/my-image.qcow2
33062 chmod +w /tmp/my-image.qcow2
33063 qemu-system-x86_64 -enable-kvm -hda /tmp/my-image.qcow2 -m 1000 \
33064 -bios $(guix build ovmf)/share/firmware/ovmf_x64.bin
33067 When using the @code{efi-raw} image type, a raw disk image is produced;
33068 it can be copied as is to a USB stick, for instance. Assuming
33069 @code{/dev/sdc} is the device corresponding to a USB stick, one can copy
33070 the image to it using the following command:
33073 # dd if=$(guix system image my-os.scm) of=/dev/sdc status=progress
33076 The @code{--list-image-types} command lists all the available image
33079 @cindex creating virtual machine images
33080 When using the @code{qcow2} image type, the returned image is in qcow2
33081 format, which the QEMU emulator can efficiently use. @xref{Running Guix
33082 in a VM}, for more information on how to run the image in a virtual
33083 machine. The @code{grub-bootloader} bootloader is always used
33084 independently of what is declared in the @code{operating-system} file
33085 passed as argument. This is to make it easier to work with QEMU, which
33086 uses the SeaBIOS BIOS by default, expecting a bootloader to be installed
33087 in the Master Boot Record (MBR).
33089 @cindex docker-image, creating docker images
33090 When using @code{docker-image}, a Docker image is produced. Guix builds
33091 the image from scratch, not from a pre-existing Docker base image. As a
33092 result, it contains @emph{exactly} what you define in the operating
33093 system configuration file. You can then load the image and launch a
33094 Docker container using commands like the following:
33097 image_id="$(docker load < guix-system-docker-image.tar.gz)"
33098 container_id="$(docker create $image_id)"
33099 docker start $container_id
33102 This command starts a new Docker container from the specified image. It
33103 will boot the Guix system in the usual manner, which means it will
33104 start any services you have defined in the operating system
33105 configuration. You can get an interactive shell running in the container
33106 using @command{docker exec}:
33109 docker exec -ti $container_id /run/current-system/profile/bin/bash --login
33112 Depending on what you run in the Docker container, it
33113 may be necessary to give the container additional permissions. For
33114 example, if you intend to build software using Guix inside of the Docker
33115 container, you may need to pass the @option{--privileged} option to
33116 @code{docker create}.
33118 Last, the @option{--network} option applies to @command{guix system
33119 docker-image}: it produces an image where network is supposedly shared
33120 with the host, and thus without services like nscd or NetworkManager.
33123 Return a script to run the operating system declared in @var{file}
33124 within a container. Containers are a set of lightweight isolation
33125 mechanisms provided by the kernel Linux-libre. Containers are
33126 substantially less resource-demanding than full virtual machines since
33127 the kernel, shared objects, and other resources can be shared with the
33128 host system; this also means they provide thinner isolation.
33130 Currently, the script must be run as root in order to support more than
33131 a single user and group. The container shares its store with the host
33134 As with the @code{vm} action (@pxref{guix system vm}), additional file
33135 systems to be shared between the host and container can be specified
33136 using the @option{--share} and @option{--expose} options:
33139 guix system container my-config.scm \
33140 --expose=$HOME --share=$HOME/tmp=/exchange
33144 This option requires Linux-libre 3.19 or newer.
33149 @var{options} can contain any of the common build options (@pxref{Common
33150 Build Options}). In addition, @var{options} can contain one of the
33154 @item --expression=@var{expr}
33155 @itemx -e @var{expr}
33156 Consider the operating-system @var{expr} evaluates to.
33157 This is an alternative to specifying a file which evaluates to an
33159 This is used to generate the Guix system installer @pxref{Building the
33160 Installation Image}).
33162 @item --system=@var{system}
33163 @itemx -s @var{system}
33164 Attempt to build for @var{system} instead of the host system type.
33165 This works as per @command{guix build} (@pxref{Invoking guix build}).
33169 Return the derivation file name of the given operating system without
33172 @cindex provenance tracking, of the operating system
33173 @item --save-provenance
33174 As discussed above, @command{guix system init} and @command{guix system
33175 reconfigure} always save provenance information @i{via} a dedicated
33176 service (@pxref{Service Reference, @code{provenance-service-type}}).
33177 However, other commands don't do that by default. If you wish to, say,
33178 create a virtual machine image that contains provenance information, you
33182 guix system image -t qcow2 --save-provenance config.scm
33185 That way, the resulting image will effectively ``embed its own source''
33186 in the form of meta-data in @file{/run/current-system}. With that
33187 information, one can rebuild the image to make sure it really contains
33188 what it pretends to contain; or they could use that to derive a variant
33191 @item --image-type=@var{type}
33192 @itemx -t @var{type}
33193 For the @code{image} action, create an image with given @var{type}.
33195 When this option is omitted, @command{guix system} uses the
33196 @code{efi-raw} image type.
33198 @cindex ISO-9660 format
33199 @cindex CD image format
33200 @cindex DVD image format
33201 @option{--image-type=iso9660} produces an ISO-9660 image, suitable
33202 for burning on CDs and DVDs.
33204 @item --image-size=@var{size}
33205 For the @code{image} action, create an image of the given @var{size}.
33206 @var{size} may be a number of bytes, or it may include a unit as a
33207 suffix (@pxref{Block size, size specifications,, coreutils, GNU
33210 When this option is omitted, @command{guix system} computes an estimate
33211 of the image size as a function of the size of the system declared in
33216 For the @code{container} action, allow containers to access the host network,
33217 that is, do not create a network namespace.
33219 @item --root=@var{file}
33220 @itemx -r @var{file}
33221 Make @var{file} a symlink to the result, and register it as a garbage
33224 @item --skip-checks
33225 Skip pre-installation safety checks.
33227 By default, @command{guix system init} and @command{guix system
33228 reconfigure} perform safety checks: they make sure the file systems that
33229 appear in the @code{operating-system} declaration actually exist
33230 (@pxref{File Systems}), and that any Linux kernel modules that may be
33231 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
33232 RAM Disk}). Passing this option skips these tests altogether.
33234 @item --allow-downgrades
33235 Instruct @command{guix system reconfigure} to allow system downgrades.
33237 By default, @command{reconfigure} prevents you from downgrading your
33238 system. It achieves that by comparing the provenance info of your
33239 system (shown by @command{guix system describe}) with that of your
33240 @command{guix} command (shown by @command{guix describe}). If the
33241 commits for @command{guix} are not descendants of those used for your
33242 system, @command{guix system reconfigure} errors out. Passing
33243 @option{--allow-downgrades} allows you to bypass these checks.
33246 Make sure you understand its security implications before using
33247 @option{--allow-downgrades}.
33251 @cindex on-error strategy
33252 @cindex error strategy
33253 @item --on-error=@var{strategy}
33254 Apply @var{strategy} when an error occurs when reading @var{file}.
33255 @var{strategy} may be one of the following:
33258 @item nothing-special
33259 Report the error concisely and exit. This is the default strategy.
33262 Likewise, but also display a backtrace.
33265 Report the error and enter Guile's debugger. From there, you can run
33266 commands such as @code{,bt} to get a backtrace, @code{,locals} to
33267 display local variable values, and more generally inspect the state of the
33268 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
33269 a list of available debugging commands.
33273 Once you have built, configured, re-configured, and re-re-configured
33274 your Guix installation, you may find it useful to list the operating
33275 system generations available on disk---and that you can choose from the
33276 bootloader boot menu:
33281 Describe the current system generation: its file name, the kernel and
33282 bootloader used, etc., as well as provenance information when available.
33284 @item list-generations
33285 List a summary of each generation of the operating system available on
33286 disk, in a human-readable way. This is similar to the
33287 @option{--list-generations} option of @command{guix package}
33288 (@pxref{Invoking guix package}).
33290 Optionally, one can specify a pattern, with the same syntax that is used
33291 in @command{guix package --list-generations}, to restrict the list of
33292 generations displayed. For instance, the following command displays
33293 generations that are up to 10 days old:
33296 $ guix system list-generations 10d
33301 The @command{guix system} command has even more to offer! The following
33302 sub-commands allow you to visualize how your system services relate to
33305 @anchor{system-extension-graph}
33308 @item extension-graph
33309 Emit to standard output the @dfn{service
33310 extension graph} of the operating system defined in @var{file}
33311 (@pxref{Service Composition}, for more information on service
33312 extensions). By default the output is in Dot/Graphviz format, but you
33313 can choose a different format with @option{--graph-backend}, as with
33314 @command{guix graph} (@pxref{Invoking guix graph, @option{--backend}}):
33319 $ guix system extension-graph @var{file} | xdot -
33322 shows the extension relations among services.
33324 @anchor{system-shepherd-graph}
33325 @item shepherd-graph
33326 Emit to standard output the @dfn{dependency
33327 graph} of shepherd services of the operating system defined in
33328 @var{file}. @xref{Shepherd Services}, for more information and for an
33331 Again, the default output format is Dot/Graphviz, but you can pass
33332 @option{--graph-backend} to select a different one.
33336 @node Invoking guix deploy
33337 @section Invoking @code{guix deploy}
33339 We've already seen @code{operating-system} declarations used to manage a
33340 machine's configuration locally. Suppose you need to configure multiple
33341 machines, though---perhaps you're managing a service on the web that's
33342 comprised of several servers. @command{guix deploy} enables you to use those
33343 same @code{operating-system} declarations to manage multiple remote hosts at
33344 once as a logical ``deployment''.
33347 The functionality described in this section is still under development
33348 and is subject to change. Get in touch with us on
33349 @email{guix-devel@@gnu.org}!
33353 guix deploy @var{file}
33356 Such an invocation will deploy the machines that the code within @var{file}
33357 evaluates to. As an example, @var{file} might contain a definition like this:
33360 ;; This is a Guix deployment of a "bare bones" setup, with
33361 ;; no X11 display server, to a machine with an SSH daemon
33362 ;; listening on localhost:2222. A configuration such as this
33363 ;; may be appropriate for virtual machine with ports
33364 ;; forwarded to the host's loopback interface.
33366 (use-service-modules networking ssh)
33367 (use-package-modules bootloaders)
33371 (host-name "gnu-deployed")
33372 (timezone "Etc/UTC")
33373 (bootloader (bootloader-configuration
33374 (bootloader grub-bootloader)
33375 (target "/dev/vda")
33376 (terminal-outputs '(console))))
33377 (file-systems (cons (file-system
33379 (device "/dev/vda1")
33381 %base-file-systems))
33383 (append (list (service dhcp-client-service-type)
33384 (service openssh-service-type
33385 (openssh-configuration
33386 (permit-root-login #t)
33387 (allow-empty-passwords? #t))))
33391 (operating-system %system)
33392 (environment managed-host-environment-type)
33393 (configuration (machine-ssh-configuration
33394 (host-name "localhost")
33395 (system "x86_64-linux")
33397 (identity "./id_rsa")
33401 The file should evaluate to a list of @var{machine} objects. This example,
33402 upon being deployed, will create a new generation on the remote system
33403 realizing the @code{operating-system} declaration @code{%system}.
33404 @code{environment} and @code{configuration} specify how the machine should be
33405 provisioned---that is, how the computing resources should be created and
33406 managed. The above example does not create any resources, as a
33407 @code{'managed-host} is a machine that is already running the Guix system and
33408 available over the network. This is a particularly simple case; a more
33409 complex deployment may involve, for example, starting virtual machines through
33410 a Virtual Private Server (VPS) provider. In such a case, a different
33411 @var{environment} type would be used.
33413 Do note that you first need to generate a key pair on the coordinator machine
33414 to allow the daemon to export signed archives of files from the store
33415 (@pxref{Invoking guix archive}), though this step is automatic on Guix
33419 # guix archive --generate-key
33423 Each target machine must authorize the key of the master machine so that it
33424 accepts store items it receives from the coordinator:
33427 # guix archive --authorize < coordinator-public-key.txt
33430 @code{user}, in this example, specifies the name of the user account to log in
33431 as to perform the deployment. Its default value is @code{root}, but root
33432 login over SSH may be forbidden in some cases. To work around this,
33433 @command{guix deploy} can log in as an unprivileged user and employ
33434 @code{sudo} to escalate privileges. This will only work if @code{sudo} is
33435 currently installed on the remote and can be invoked non-interactively as
33436 @code{user}. That is, the line in @code{sudoers} granting @code{user} the
33437 ability to use @code{sudo} must contain the @code{NOPASSWD} tag. This can
33438 be accomplished with the following operating system configuration snippet:
33442 (gnu system)) ;for %sudoers-specification
33444 (define %user "username")
33449 (plain-file "sudoers"
33450 (string-append (plain-file-content %sudoers-specification)
33451 (format #f "~a ALL = NOPASSWD: ALL~%"
33456 For more information regarding the format of the @file{sudoers} file,
33457 consult @command{man sudoers}.
33459 @deftp {Data Type} machine
33460 This is the data type representing a single machine in a heterogeneous Guix
33464 @item @code{operating-system}
33465 The object of the operating system configuration to deploy.
33467 @item @code{environment}
33468 An @code{environment-type} describing how the machine should be provisioned.
33470 @item @code{configuration} (default: @code{#f})
33471 An object describing the configuration for the machine's @code{environment}.
33472 If the @code{environment} has a default configuration, @code{#f} may be used.
33473 If @code{#f} is used for an environment with no default configuration,
33474 however, an error will be thrown.
33478 @deftp {Data Type} machine-ssh-configuration
33479 This is the data type representing the SSH client parameters for a machine
33480 with an @code{environment} of @code{managed-host-environment-type}.
33483 @item @code{host-name}
33484 @item @code{build-locally?} (default: @code{#t})
33485 If false, system derivations will be built on the machine being deployed to.
33486 @item @code{system}
33487 The system type describing the architecture of the machine being deployed
33488 to---e.g., @code{"x86_64-linux"}.
33489 @item @code{authorize?} (default: @code{#t})
33490 If true, the coordinator's signing key will be added to the remote's ACL
33492 @item @code{port} (default: @code{22})
33493 @item @code{user} (default: @code{"root"})
33494 @item @code{identity} (default: @code{#f})
33495 If specified, the path to the SSH private key to use to authenticate with the
33498 @item @code{host-key} (default: @code{#f})
33499 This should be the SSH host key of the machine, which looks like this:
33502 ssh-ed25519 AAAAC3Nz@dots{} root@@example.org
33505 When @code{host-key} is @code{#f}, the server is authenticated against
33506 the @file{~/.ssh/known_hosts} file, just like the OpenSSH @command{ssh}
33509 @item @code{allow-downgrades?} (default: @code{#f})
33510 Whether to allow potential downgrades.
33512 Like @command{guix system reconfigure}, @command{guix deploy} compares
33513 the channel commits currently deployed on the remote host (as returned
33514 by @command{guix system describe}) to those currently in use (as
33515 returned by @command{guix describe}) to determine whether commits
33516 currently in use are descendants of those deployed. When this is not
33517 the case and @code{allow-downgrades?} is false, it raises an error.
33518 This ensures you do not accidentally downgrade remote machines.
33522 @deftp {Data Type} digital-ocean-configuration
33523 This is the data type describing the Droplet that should be created for a
33524 machine with an @code{environment} of @code{digital-ocean-environment-type}.
33527 @item @code{ssh-key}
33528 The path to the SSH private key to use to authenticate with the remote
33529 host. In the future, this field may not exist.
33531 A list of string ``tags'' that uniquely identify the machine. Must be given
33532 such that no two machines in the deployment have the same set of tags.
33533 @item @code{region}
33534 A Digital Ocean region slug, such as @code{"nyc3"}.
33536 A Digital Ocean size slug, such as @code{"s-1vcpu-1gb"}
33537 @item @code{enable-ipv6?}
33538 Whether or not the droplet should be created with IPv6 networking.
33542 @node Running Guix in a VM
33543 @section Running Guix in a Virtual Machine
33545 @cindex virtual machine
33546 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
33548 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
33549 This image is a compressed image in QCOW format. You will first need to
33550 decompress with @command{xz -d}, and then you can pass it to an emulator such
33551 as QEMU (see below for details).
33553 This image boots the Xfce graphical environment and it contains some
33554 commonly used tools. You can install more software in the image by running
33555 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
33556 also reconfigure the system based on its initial configuration file available
33557 as @file{/run/current-system/configuration.scm} (@pxref{Using the
33558 Configuration System}).
33560 Instead of using this pre-built image, one can also build their own virtual
33561 machine image using @command{guix system vm-image} (@pxref{Invoking guix
33562 system}). The returned image is in qcow2 format, which the
33563 @uref{https://qemu.org/, QEMU emulator} can efficiently use.
33566 If you built your own image, you must copy it out of the store
33567 (@pxref{The Store}) and give yourself permission to write to the copy
33568 before you can use it. When invoking QEMU, you must choose a system
33569 emulator that is suitable for your hardware platform. Here is a minimal
33570 QEMU invocation that will boot the result of @command{guix system
33571 image -t qcow2} on x86_64 hardware:
33574 $ qemu-system-x86_64 \
33575 -nic user,model=virtio-net-pci \
33576 -enable-kvm -m 1024 \
33577 -device virtio-blk,drive=myhd \
33578 -drive if=none,file=/tmp/qemu-image,id=myhd
33581 Here is what each of these options means:
33584 @item qemu-system-x86_64
33585 This specifies the hardware platform to emulate. This should match the
33588 @item -nic user,model=virtio-net-pci
33589 Enable the unprivileged user-mode network stack. The guest OS can
33590 access the host but not vice versa. This is the simplest way to get the
33591 guest OS online. @code{model} specifies which network device to emulate:
33592 @code{virtio-net-pci} is a special device made for virtualized operating
33593 systems and recommended for most uses. Assuming your hardware platform is
33594 x86_64, you can get a list of available NIC models by running
33595 @command{qemu-system-x86_64 -nic model=help}.
33598 If your system has hardware virtualization extensions, enabling the
33599 virtual machine support (KVM) of the Linux kernel will make things run
33602 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
33604 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
33605 which may be insufficient for some operations.
33607 @item -device virtio-blk,drive=myhd
33608 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
33609 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
33610 better performance than if it were emulating a complete disk drive. See the
33611 QEMU and KVM documentation for more info.
33613 @item -drive if=none,file=/tmp/qemu-image,id=myhd
33614 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing
33615 store of the ``myhd'' drive.
33618 The default @command{run-vm.sh} script that is returned by an invocation of
33619 @command{guix system vm} does not add a @command{-nic user} flag by default.
33620 To get network access from within the vm add the @code{(dhcp-client-service)}
33621 to your system definition and start the VM using
33622 @command{$(guix system vm config.scm) -nic user}. An important caveat of using
33623 @command{-nic user} for networking is that @command{ping} will not work, because
33624 it uses the ICMP protocol. You'll have to use a different command to check for
33625 network connectivity, for example @command{guix download}.
33627 @subsection Connecting Through SSH
33631 To enable SSH inside a VM you need to add an SSH server like
33632 @code{openssh-service-type} to your VM (@pxref{Networking Services,
33633 @code{openssh-service-type}}). In addition you need to forward the SSH port,
33634 22 by default, to the host. You can do this with
33637 $(guix system vm config.scm) -nic user,model=virtio-net-pci,hostfwd=tcp::10022-:22
33640 To connect to the VM you can run
33643 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022 localhost
33646 The @command{-p} tells @command{ssh} the port you want to connect to.
33647 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
33648 every time you modify your @command{config.scm} file and the
33649 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
33650 connection to an unknown host every time you connect.
33652 @subsection Using @command{virt-viewer} with Spice
33654 As an alternative to the default @command{qemu} graphical client you can
33655 use the @command{remote-viewer} from the @command{virt-viewer} package. To
33656 connect pass the @command{-spice port=5930,disable-ticketing} flag to
33657 @command{qemu}. See previous section for further information on how to do this.
33659 Spice also allows you to do some nice stuff like share your clipboard with your
33660 VM@. To enable that you'll also have to pass the following flags to @command{qemu}:
33663 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
33664 -chardev spicevmc,name=vdagent,id=vdagent
33665 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
33666 name=com.redhat.spice.0
33669 You'll also need to add the @code{(spice-vdagent-service)} to your
33670 system definition (@pxref{Miscellaneous Services, Spice service}).
33672 @node Defining Services
33673 @section Defining Services
33675 The previous sections show the available services and how one can combine
33676 them in an @code{operating-system} declaration. But how do we define
33677 them in the first place? And what is a service anyway?
33680 * Service Composition:: The model for composing services.
33681 * Service Types and Services:: Types and services.
33682 * Service Reference:: API reference.
33683 * Shepherd Services:: A particular type of service.
33686 @node Service Composition
33687 @subsection Service Composition
33691 Here we define a @dfn{service} as, broadly, something that extends the
33692 functionality of the operating system. Often a service is a process---a
33693 @dfn{daemon}---started when the system boots: a secure shell server, a
33694 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
33695 whose execution can be triggered by another daemon---e.g., an FTP server
33696 started by @command{inetd} or a D-Bus service activated by
33697 @command{dbus-daemon}. Occasionally, a service does not map to a
33698 daemon. For instance, the ``account'' service collects user accounts
33699 and makes sure they exist when the system runs; the ``udev'' service
33700 collects device management rules and makes them available to the eudev
33701 daemon; the @file{/etc} service populates the @file{/etc} directory
33704 @cindex service extensions
33705 Guix system services are connected by @dfn{extensions}. For instance, the
33706 secure shell service @emph{extends} the Shepherd---the
33707 initialization system, running as PID@tie{}1---by giving it the command
33708 lines to start and stop the secure shell daemon (@pxref{Networking
33709 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
33710 service by passing it its @file{.service} specification, and extends the
33711 udev service by passing it device management rules (@pxref{Desktop
33712 Services, @code{upower-service}}); the Guix daemon service extends the
33713 Shepherd by passing it the command lines to start and stop the daemon,
33714 and extends the account service by passing it a list of required build
33715 user accounts (@pxref{Base Services}).
33717 All in all, services and their ``extends'' relations form a directed
33718 acyclic graph (DAG). If we represent services as boxes and extensions
33719 as arrows, a typical system might provide something like this:
33721 @image{images/service-graph,,5in,Typical service extension graph.}
33723 @cindex system service
33724 At the bottom, we see the @dfn{system service}, which produces the
33725 directory containing everything to run and boot the system, as returned
33726 by the @command{guix system build} command. @xref{Service Reference},
33727 to learn about the other service types shown here.
33728 @xref{system-extension-graph, the @command{guix system extension-graph}
33729 command}, for information on how to generate this representation for a
33730 particular operating system definition.
33732 @cindex service types
33733 Technically, developers can define @dfn{service types} to express these
33734 relations. There can be any number of services of a given type on the
33735 system---for instance, a system running two instances of the GNU secure
33736 shell server (lsh) has two instances of @code{lsh-service-type}, with
33737 different parameters.
33739 The following section describes the programming interface for service
33740 types and services.
33742 @node Service Types and Services
33743 @subsection Service Types and Services
33745 A @dfn{service type} is a node in the DAG described above. Let us start
33746 with a simple example, the service type for the Guix build daemon
33747 (@pxref{Invoking guix-daemon}):
33750 (define guix-service-type
33754 (list (service-extension shepherd-root-service-type guix-shepherd-service)
33755 (service-extension account-service-type guix-accounts)
33756 (service-extension activation-service-type guix-activation)))
33757 (default-value (guix-configuration))))
33761 It defines three things:
33765 A name, whose sole purpose is to make inspection and debugging easier.
33768 A list of @dfn{service extensions}, where each extension designates the
33769 target service type and a procedure that, given the parameters of the
33770 service, returns a list of objects to extend the service of that type.
33772 Every service type has at least one service extension. The only
33773 exception is the @dfn{boot service type}, which is the ultimate service.
33776 Optionally, a default value for instances of this type.
33779 In this example, @code{guix-service-type} extends three services:
33782 @item shepherd-root-service-type
33783 The @code{guix-shepherd-service} procedure defines how the Shepherd
33784 service is extended. Namely, it returns a @code{<shepherd-service>}
33785 object that defines how @command{guix-daemon} is started and stopped
33786 (@pxref{Shepherd Services}).
33788 @item account-service-type
33789 This extension for this service is computed by @code{guix-accounts},
33790 which returns a list of @code{user-group} and @code{user-account}
33791 objects representing the build user accounts (@pxref{Invoking
33794 @item activation-service-type
33795 Here @code{guix-activation} is a procedure that returns a gexp, which is
33796 a code snippet to run at ``activation time''---e.g., when the service is
33800 A service of this type is instantiated like this:
33803 (service guix-service-type
33804 (guix-configuration
33806 (extra-options '("--gc-keep-derivations"))))
33809 The second argument to the @code{service} form is a value representing
33810 the parameters of this specific service instance.
33811 @xref{guix-configuration-type, @code{guix-configuration}}, for
33812 information about the @code{guix-configuration} data type. When the
33813 value is omitted, the default value specified by
33814 @code{guix-service-type} is used:
33817 (service guix-service-type)
33820 @code{guix-service-type} is quite simple because it extends other
33821 services but is not extensible itself.
33823 @c @subsubsubsection Extensible Service Types
33825 The service type for an @emph{extensible} service looks like this:
33828 (define udev-service-type
33829 (service-type (name 'udev)
33831 (list (service-extension shepherd-root-service-type
33832 udev-shepherd-service)))
33834 (compose concatenate) ;concatenate the list of rules
33835 (extend (lambda (config rules)
33837 (($ <udev-configuration> udev initial-rules)
33838 (udev-configuration
33839 (udev udev) ;the udev package to use
33840 (rules (append initial-rules rules)))))))))
33843 This is the service type for the
33844 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
33845 management daemon}. Compared to the previous example, in addition to an
33846 extension of @code{shepherd-root-service-type}, we see two new fields:
33850 This is the procedure to @dfn{compose} the list of extensions to
33851 services of this type.
33853 Services can extend the udev service by passing it lists of rules; we
33854 compose those extensions simply by concatenating them.
33857 This procedure defines how the value of the service is @dfn{extended} with
33858 the composition of the extensions.
33860 Udev extensions are composed into a list of rules, but the udev service
33861 value is itself a @code{<udev-configuration>} record. So here, we
33862 extend that record by appending the list of rules it contains to the
33863 list of contributed rules.
33866 This is a string giving an overview of the service type. The string can
33867 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
33868 @command{guix system search} command searches these strings and displays
33869 them (@pxref{Invoking guix system}).
33872 There can be only one instance of an extensible service type such as
33873 @code{udev-service-type}. If there were more, the
33874 @code{service-extension} specifications would be ambiguous.
33876 Still here? The next section provides a reference of the programming
33877 interface for services.
33879 @node Service Reference
33880 @subsection Service Reference
33882 We have seen an overview of service types (@pxref{Service Types and
33883 Services}). This section provides a reference on how to manipulate
33884 services and service types. This interface is provided by the
33885 @code{(gnu services)} module.
33887 @deffn {Scheme Procedure} service @var{type} [@var{value}]
33888 Return a new service of @var{type}, a @code{<service-type>} object (see
33889 below). @var{value} can be any object; it represents the parameters of
33890 this particular service instance.
33892 When @var{value} is omitted, the default value specified by @var{type}
33893 is used; if @var{type} does not specify a default value, an error is
33896 For instance, this:
33899 (service openssh-service-type)
33903 is equivalent to this:
33906 (service openssh-service-type
33907 (openssh-configuration))
33910 In both cases the result is an instance of @code{openssh-service-type}
33911 with the default configuration.
33914 @deffn {Scheme Procedure} service? @var{obj}
33915 Return true if @var{obj} is a service.
33918 @deffn {Scheme Procedure} service-kind @var{service}
33919 Return the type of @var{service}---i.e., a @code{<service-type>} object.
33922 @deffn {Scheme Procedure} service-value @var{service}
33923 Return the value associated with @var{service}. It represents its
33927 Here is an example of how a service is created and manipulated:
33931 (service nginx-service-type
33932 (nginx-configuration
33934 (log-directory log-directory)
33935 (run-directory run-directory)
33936 (file config-file))))
33941 (eq? (service-kind s) nginx-service-type)
33945 The @code{modify-services} form provides a handy way to change the
33946 parameters of some of the services of a list such as
33947 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
33948 evaluates to a list of services. Of course, you could always use
33949 standard list combinators such as @code{map} and @code{fold} to do that
33950 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
33951 @code{modify-services} simply provides a more concise form for this
33954 @deffn {Scheme Syntax} modify-services @var{services} @
33955 (@var{type} @var{variable} => @var{body}) @dots{}
33957 Modify the services listed in @var{services} according to the given
33958 clauses. Each clause has the form:
33961 (@var{type} @var{variable} => @var{body})
33964 where @var{type} is a service type---e.g.,
33965 @code{guix-service-type}---and @var{variable} is an identifier that is
33966 bound within the @var{body} to the service parameters---e.g., a
33967 @code{guix-configuration} instance---of the original service of that
33970 The @var{body} should evaluate to the new service parameters, which will
33971 be used to configure the new service. This new service will replace the
33972 original in the resulting list. Because a service's service parameters
33973 are created using @code{define-record-type*}, you can write a succinct
33974 @var{body} that evaluates to the new service parameters by using the
33975 @code{inherit} feature that @code{define-record-type*} provides.
33977 @xref{Using the Configuration System}, for example usage.
33981 Next comes the programming interface for service types. This is
33982 something you want to know when writing new service definitions, but not
33983 necessarily when simply looking for ways to customize your
33984 @code{operating-system} declaration.
33986 @deftp {Data Type} service-type
33987 @cindex service type
33988 This is the representation of a @dfn{service type} (@pxref{Service Types
33993 This is a symbol, used only to simplify inspection and debugging.
33995 @item @code{extensions}
33996 A non-empty list of @code{<service-extension>} objects (see below).
33998 @item @code{compose} (default: @code{#f})
33999 If this is @code{#f}, then the service type denotes services that cannot
34000 be extended---i.e., services that do not receive ``values'' from other
34003 Otherwise, it must be a one-argument procedure. The procedure is called
34004 by @code{fold-services} and is passed a list of values collected from
34005 extensions. It may return any single value.
34007 @item @code{extend} (default: @code{#f})
34008 If this is @code{#f}, services of this type cannot be extended.
34010 Otherwise, it must be a two-argument procedure: @code{fold-services}
34011 calls it, passing it the initial value of the service as the first
34012 argument and the result of applying @code{compose} to the extension
34013 values as the second argument. It must return a value that is a valid
34014 parameter value for the service instance.
34016 @item @code{description}
34017 This is a string, possibly using Texinfo markup, describing in a couple
34018 of sentences what the service is about. This string allows users to
34019 find about the service through @command{guix system search}
34020 (@pxref{Invoking guix system}).
34022 @item @code{default-value} (default: @code{&no-default-value})
34023 The default value associated for instances of this service type. This
34024 allows users to use the @code{service} form without its second argument:
34027 (service @var{type})
34030 The returned service in this case has the default value specified by
34034 @xref{Service Types and Services}, for examples.
34037 @deffn {Scheme Procedure} service-extension @var{target-type} @
34039 Return a new extension for services of type @var{target-type}.
34040 @var{compute} must be a one-argument procedure: @code{fold-services}
34041 calls it, passing it the value associated with the service that provides
34042 the extension; it must return a valid value for the target service.
34045 @deffn {Scheme Procedure} service-extension? @var{obj}
34046 Return true if @var{obj} is a service extension.
34049 Occasionally, you might want to simply extend an existing service. This
34050 involves creating a new service type and specifying the extension of
34051 interest, which can be verbose; the @code{simple-service} procedure
34052 provides a shorthand for this.
34054 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
34055 Return a service that extends @var{target} with @var{value}. This works
34056 by creating a singleton service type @var{name}, of which the returned
34057 service is an instance.
34059 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
34063 (simple-service 'my-mcron-job mcron-service-type
34064 #~(job '(next-hour (3)) "guix gc -F 2G"))
34068 At the core of the service abstraction lies the @code{fold-services}
34069 procedure, which is responsible for ``compiling'' a list of services
34070 down to a single directory that contains everything needed to boot and
34071 run the system---the directory shown by the @command{guix system build}
34072 command (@pxref{Invoking guix system}). In essence, it propagates
34073 service extensions down the service graph, updating each node parameters
34074 on the way, until it reaches the root node.
34076 @deffn {Scheme Procedure} fold-services @var{services} @
34077 [#:target-type @var{system-service-type}]
34078 Fold @var{services} by propagating their extensions down to the root of
34079 type @var{target-type}; return the root service adjusted accordingly.
34082 Lastly, the @code{(gnu services)} module also defines several essential
34083 service types, some of which are listed below.
34085 @defvr {Scheme Variable} system-service-type
34086 This is the root of the service graph. It produces the system directory
34087 as returned by the @command{guix system build} command.
34090 @defvr {Scheme Variable} boot-service-type
34091 The type of the ``boot service'', which produces the @dfn{boot script}.
34092 The boot script is what the initial RAM disk runs when booting.
34095 @defvr {Scheme Variable} etc-service-type
34096 The type of the @file{/etc} service. This service is used to create
34097 files under @file{/etc} and can be extended by
34098 passing it name/file tuples such as:
34101 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
34104 In this example, the effect would be to add an @file{/etc/issue} file
34105 pointing to the given file.
34108 @defvr {Scheme Variable} setuid-program-service-type
34109 Type for the ``setuid-program service''. This service collects lists of
34110 executable file names, passed as gexps, and adds them to the set of
34111 setuid-root programs on the system (@pxref{Setuid Programs}).
34114 @defvr {Scheme Variable} profile-service-type
34115 Type of the service that populates the @dfn{system profile}---i.e., the
34116 programs under @file{/run/current-system/profile}. Other services can
34117 extend it by passing it lists of packages to add to the system profile.
34120 @cindex provenance tracking, of the operating system
34121 @anchor{provenance-service-type}
34122 @defvr {Scheme Variable} provenance-service-type
34123 This is the type of the service that records @dfn{provenance meta-data}
34124 in the system itself. It creates several files under
34125 @file{/run/current-system}:
34129 This is a ``channel file'' that can be passed to @command{guix pull -C}
34130 or @command{guix time-machine -C}, and which describes the channels used
34131 to build the system, if that information was available
34132 (@pxref{Channels}).
34134 @item configuration.scm
34135 This is the file that was passed as the value for this
34136 @code{provenance-service-type} service. By default, @command{guix
34137 system reconfigure} automatically passes the OS configuration file it
34138 received on the command line.
34141 This contains the same information as the two other files but in a
34142 format that is more readily processable.
34145 In general, these two pieces of information (channels and configuration
34146 file) are enough to reproduce the operating system ``from source''.
34149 This information is necessary to rebuild your operating system, but it
34150 is not always sufficient. In particular, @file{configuration.scm}
34151 itself is insufficient if it is not self-contained---if it refers to
34152 external Guile modules or to extra files. If you want
34153 @file{configuration.scm} to be self-contained, we recommend that modules
34154 or files it refers to be part of a channel.
34156 Besides, provenance meta-data is ``silent'' in the sense that it does
34157 not change the bits contained in your system, @emph{except for the
34158 meta-data bits themselves}. Two different OS configurations or sets of
34159 channels can lead to the same system, bit-for-bit; when
34160 @code{provenance-service-type} is used, these two systems will have
34161 different meta-data and thus different store file names, which makes
34162 comparison less trivial.
34165 This service is automatically added to your operating system
34166 configuration when you use @command{guix system reconfigure},
34167 @command{guix system init}, or @command{guix deploy}.
34170 @node Shepherd Services
34171 @subsection Shepherd Services
34173 @cindex shepherd services
34175 @cindex init system
34176 The @code{(gnu services shepherd)} module provides a way to define
34177 services managed by the GNU@tie{}Shepherd, which is the
34178 initialization system---the first process that is started when the
34179 system boots, also known as PID@tie{}1
34180 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
34182 Services in the Shepherd can depend on each other. For instance, the
34183 SSH daemon may need to be started after the syslog daemon has been
34184 started, which in turn can only happen once all the file systems have
34185 been mounted. The simple operating system defined earlier (@pxref{Using
34186 the Configuration System}) results in a service graph like this:
34188 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
34190 You can actually generate such a graph for any operating system
34191 definition using the @command{guix system shepherd-graph} command
34192 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
34194 The @code{%shepherd-root-service} is a service object representing
34195 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
34196 by passing it lists of @code{<shepherd-service>} objects.
34198 @deftp {Data Type} shepherd-service
34199 The data type representing a service managed by the Shepherd.
34202 @item @code{provision}
34203 This is a list of symbols denoting what the service provides.
34205 These are the names that may be passed to @command{herd start},
34206 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
34207 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
34208 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
34210 @item @code{requirement} (default: @code{'()})
34211 List of symbols denoting the Shepherd services this one depends on.
34213 @cindex one-shot services, for the Shepherd
34214 @item @code{one-shot?} (default: @code{#f})
34215 Whether this service is @dfn{one-shot}. One-shot services stop immediately
34216 after their @code{start} action has completed. @xref{Slots of services,,,
34217 shepherd, The GNU Shepherd Manual}, for more info.
34219 @item @code{respawn?} (default: @code{#t})
34220 Whether to restart the service when it stops, for instance when the
34221 underlying process dies.
34224 @itemx @code{stop} (default: @code{#~(const #f)})
34225 The @code{start} and @code{stop} fields refer to the Shepherd's
34226 facilities to start and stop processes (@pxref{Service De- and
34227 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
34228 G-expressions that get expanded in the Shepherd configuration file
34229 (@pxref{G-Expressions}).
34231 @item @code{actions} (default: @code{'()})
34232 @cindex actions, of Shepherd services
34233 This is a list of @code{shepherd-action} objects (see below) defining
34234 @dfn{actions} supported by the service, in addition to the standard
34235 @code{start} and @code{stop} actions. Actions listed here become available as
34236 @command{herd} sub-commands:
34239 herd @var{action} @var{service} [@var{arguments}@dots{}]
34242 @item @code{auto-start?} (default: @code{#t})
34243 Whether this service should be started automatically by the Shepherd. If it
34244 is @code{#f} the service has to be started manually with @code{herd start}.
34246 @item @code{documentation}
34247 A documentation string, as shown when running:
34250 herd doc @var{service-name}
34253 where @var{service-name} is one of the symbols in @code{provision}
34254 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
34256 @item @code{modules} (default: @code{%default-modules})
34257 This is the list of modules that must be in scope when @code{start} and
34258 @code{stop} are evaluated.
34263 The example below defines a Shepherd service that spawns
34264 @command{syslogd}, the system logger from the GNU Networking Utilities
34265 (@pxref{syslogd invocation, @command{syslogd},, inetutils, GNU
34269 (let ((config (plain-file "syslogd.conf" "@dots{}")))
34271 (documentation "Run the syslog daemon (syslogd).")
34272 (provision '(syslogd))
34273 (requirement '(user-processes))
34274 (start #~(make-forkexec-constructor
34275 (list #$(file-append inetutils "/libexec/syslogd")
34276 "--rcfile" #$config)
34277 #:pid-file "/var/run/syslog.pid"))
34278 (stop #~(make-kill-destructor))))
34281 Key elements in this example are the @code{start} and @code{stop}
34282 fields: they are @dfn{staged} code snippets that use the
34283 @code{make-forkexec-constructor} procedure provided by the Shepherd and
34284 its dual, @code{make-kill-destructor} (@pxref{Service De- and
34285 Constructors,,, shepherd, The GNU Shepherd Manual}). The @code{start}
34286 field will have @command{shepherd} spawn @command{syslogd} with the
34287 given option; note that we pass @code{config} after @option{--rcfile},
34288 which is a configuration file declared above (contents of this file are
34289 omitted). Likewise, the @code{stop} field tells how this service is to
34290 be stopped; in this case, it is stopped by making the @code{kill} system
34291 call on its PID@. Code staging is achieved using G-expressions:
34292 @code{#~} stages code, while @code{#$} ``escapes'' back to host code
34293 (@pxref{G-Expressions}).
34295 @deftp {Data Type} shepherd-action
34296 This is the data type that defines additional actions implemented by a
34297 Shepherd service (see above).
34301 Symbol naming the action.
34303 @item documentation
34304 This is a documentation string for the action. It can be viewed by running:
34307 herd doc @var{service} action @var{action}
34311 This should be a gexp that evaluates to a procedure of at least one argument,
34312 which is the ``running value'' of the service (@pxref{Slots of services,,,
34313 shepherd, The GNU Shepherd Manual}).
34316 The following example defines an action called @code{say-hello} that kindly
34322 (documentation "Say hi!")
34323 (procedure #~(lambda (running . args)
34324 (format #t "Hello, friend! arguments: ~s\n"
34329 Assuming this action is added to the @code{example} service, then you can do:
34332 # herd say-hello example
34333 Hello, friend! arguments: ()
34334 # herd say-hello example a b c
34335 Hello, friend! arguments: ("a" "b" "c")
34338 This, as you can see, is a fairly sophisticated way to say hello.
34339 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
34343 @defvr {Scheme Variable} shepherd-root-service-type
34344 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
34346 This is the service type that extensions target when they want to create
34347 shepherd services (@pxref{Service Types and Services}, for an example).
34348 Each extension must pass a list of @code{<shepherd-service>}. Its
34349 value must be a @code{shepherd-configuration}, as described below.
34352 @deftp {Data Type} shepherd-configuration
34353 This data type represents the Shepherd's configuration.
34356 @item shepherd (default: @code{shepherd})
34357 The Shepherd package to use.
34359 @item services (default: @code{'()})
34360 A list of @code{<shepherd-service>} to start.
34361 You should probably use the service extension
34362 mechanism instead (@pxref{Shepherd Services}).
34366 The following example specifies the Shepherd package for the operating
34372 (services (append (list openssh-service-type))
34376 ;; Use own Shepherd package.
34377 (essential-services
34378 (modify-services (operating-system-default-essential-services
34379 this-operating-system)
34380 (shepherd-root-service-type config => (shepherd-configuration
34382 (shepherd my-shepherd))))))
34385 @defvr {Scheme Variable} %shepherd-root-service
34386 This service represents PID@tie{}1.
34390 @node Documentation
34391 @chapter Documentation
34393 @cindex documentation, searching for
34394 @cindex searching for documentation
34395 @cindex Info, documentation format
34397 @cindex manual pages
34398 In most cases packages installed with Guix come with documentation.
34399 There are two main documentation formats: ``Info'', a browsable
34400 hypertext format used for GNU software, and ``manual pages'' (or ``man
34401 pages''), the linear documentation format traditionally found on Unix.
34402 Info manuals are accessed with the @command{info} command or with Emacs,
34403 and man pages are accessed using @command{man}.
34405 You can look for documentation of software installed on your system by
34406 keyword. For example, the following command searches for information
34407 about ``TLS'' in Info manuals:
34411 "(emacs)Network Security" -- STARTTLS
34412 "(emacs)Network Security" -- TLS
34413 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
34414 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
34419 The command below searches for the same keyword in man pages:
34423 SSL (7) - OpenSSL SSL/TLS library
34424 certtool (1) - GnuTLS certificate tool
34428 These searches are purely local to your computer so you have the
34429 guarantee that documentation you find corresponds to what you have
34430 actually installed, you can access it off-line, and your privacy is
34433 Once you have these results, you can view the relevant documentation by
34437 $ info "(gnutls)Core TLS API"
34447 Info manuals contain sections and indices as well as hyperlinks like
34448 those found in Web pages. The @command{info} reader (@pxref{Top, Info
34449 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
34450 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
34451 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
34452 Introduction}, for an introduction to Info navigation.
34454 @node Installing Debugging Files
34455 @chapter Installing Debugging Files
34457 @cindex debugging files
34458 Program binaries, as produced by the GCC compilers for instance, are
34459 typically written in the ELF format, with a section containing
34460 @dfn{debugging information}. Debugging information is what allows the
34461 debugger, GDB, to map binary code to source code; it is required to
34462 debug a compiled program in good conditions.
34464 This chapter explains how to use separate debug info when packages
34465 provide it, and how to rebuild packages with debug info when it's
34469 * Separate Debug Info:: Installing 'debug' outputs.
34470 * Rebuilding Debug Info:: Building missing debug info.
34473 @node Separate Debug Info
34474 @section Separate Debug Info
34476 The problem with debugging information is that is takes up a fair amount
34477 of disk space. For example, debugging information for the GNU C Library
34478 weighs in at more than 60 MiB@. Thus, as a user, keeping all the
34479 debugging info of all the installed programs is usually not an option.
34480 Yet, space savings should not come at the cost of an impediment to
34481 debugging---especially in the GNU system, which should make it easier
34482 for users to exert their computing freedom (@pxref{GNU Distribution}).
34484 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
34485 mechanism that allows users to get the best of both worlds: debugging
34486 information can be stripped from the binaries and stored in separate
34487 files. GDB is then able to load debugging information from those files,
34488 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
34491 The GNU distribution takes advantage of this by storing debugging
34492 information in the @code{lib/debug} sub-directory of a separate package
34493 output unimaginatively called @code{debug} (@pxref{Packages with
34494 Multiple Outputs}). Users can choose to install the @code{debug} output
34495 of a package when they need it. For instance, the following command
34496 installs the debugging information for the GNU C Library and for GNU
34500 guix install glibc:debug guile:debug
34503 GDB must then be told to look for debug files in the user's profile, by
34504 setting the @code{debug-file-directory} variable (consider setting it
34505 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
34509 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
34512 From there on, GDB will pick up debugging information from the
34513 @file{.debug} files under @file{~/.guix-profile/lib/debug}.
34515 In addition, you will most likely want GDB to be able to show the source
34516 code being debugged. To do that, you will have to unpack the source
34517 code of the package of interest (obtained with @code{guix build
34518 --source}, @pxref{Invoking guix build}), and to point GDB to that source
34519 directory using the @code{directory} command (@pxref{Source Path,
34520 @code{directory},, gdb, Debugging with GDB}).
34522 @c XXX: keep me up-to-date
34523 The @code{debug} output mechanism in Guix is implemented by the
34524 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
34525 opt-in---debugging information is available only for the packages with
34526 definitions explicitly declaring a @code{debug} output. To check
34527 whether a package has a @code{debug} output, use @command{guix package
34528 --list-available} (@pxref{Invoking guix package}).
34530 Read on for how to deal with packages lacking a @code{debug} output.
34532 @node Rebuilding Debug Info
34533 @section Rebuilding Debug Info
34535 @cindex debugging info, rebuilding
34536 As we saw above, some packages, but not all, provide debugging info in a
34537 @code{debug} output. What can you do when debugging info is missing?
34538 The @option{--with-debug-info} option provides a solution to that: it
34539 allows you to rebuild the package(s) for which debugging info is
34540 missing---and only those---and to graft those onto the application
34541 you're debugging. Thus, while it's not as fast as installing a
34542 @code{debug} output, it is relatively inexpensive.
34544 Let's illustrate that. Suppose you're experiencing a bug in Inkscape
34545 and would like to see what's going on in GLib, a library that's deep
34546 down in its dependency graph. As it turns out, GLib does not have a
34547 @code{debug} output and the backtrace GDB shows is all sadness:
34551 #0 0x00007ffff5f92190 in g_getenv ()
34552 from /gnu/store/@dots{}-glib-2.62.6/lib/libglib-2.0.so.0
34553 #1 0x00007ffff608a7d6 in gobject_init_ctor ()
34554 from /gnu/store/@dots{}-glib-2.62.6/lib/libgobject-2.0.so.0
34555 #2 0x00007ffff7fe275a in call_init (l=<optimized out>, argc=argc@@entry=1, argv=argv@@entry=0x7fffffffcfd8,
34556 env=env@@entry=0x7fffffffcfe8) at dl-init.c:72
34557 #3 0x00007ffff7fe2866 in call_init (env=0x7fffffffcfe8, argv=0x7fffffffcfd8, argc=1, l=<optimized out>)
34561 To address that, you install Inkscape linked against a variant GLib that
34562 contains debug info:
34565 guix install inkscape --with-debug-info=glib
34568 This time, debugging will be a whole lot nicer:
34571 $ gdb --args sh -c 'exec inkscape'
34574 Function "g_getenv" not defined.
34575 Make breakpoint pending on future shared library load? (y or [n]) y
34576 Breakpoint 1 (g_getenv) pending.
34578 Starting program: /gnu/store/@dots{}-profile/bin/sh -c exec\ inkscape
34581 #0 g_getenv (variable=variable@@entry=0x7ffff60c7a2e "GOBJECT_DEBUG") at ../glib-2.62.6/glib/genviron.c:252
34582 #1 0x00007ffff608a7d6 in gobject_init () at ../glib-2.62.6/gobject/gtype.c:4380
34583 #2 gobject_init_ctor () at ../glib-2.62.6/gobject/gtype.c:4493
34584 #3 0x00007ffff7fe275a in call_init (l=<optimized out>, argc=argc@@entry=3, argv=argv@@entry=0x7fffffffd088,
34585 env=env@@entry=0x7fffffffd0a8) at dl-init.c:72
34591 Note that there can be packages for which @option{--with-debug-info}
34592 will not have the desired effect. @xref{Package Transformation Options,
34593 @option{--with-debug-info}}, for more information.
34595 @node Security Updates
34596 @chapter Security Updates
34598 @cindex security updates
34599 @cindex security vulnerabilities
34600 Occasionally, important security vulnerabilities are discovered in software
34601 packages and must be patched. Guix developers try hard to keep track of
34602 known vulnerabilities and to apply fixes as soon as possible in the
34603 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
34604 containing only security updates). The @command{guix lint} tool helps
34605 developers find out about vulnerable versions of software packages in the
34610 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
34611 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
34612 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
34616 @xref{Invoking guix lint}, for more information.
34618 Guix follows a functional
34619 package management discipline (@pxref{Introduction}), which implies
34620 that, when a package is changed, @emph{every package that depends on it}
34621 must be rebuilt. This can significantly slow down the deployment of
34622 fixes in core packages such as libc or Bash, since basically the whole
34623 distribution would need to be rebuilt. Using pre-built binaries helps
34624 (@pxref{Substitutes}), but deployment may still take more time than
34628 To address this, Guix implements @dfn{grafts}, a mechanism that allows
34629 for fast deployment of critical updates without the costs associated
34630 with a whole-distribution rebuild. The idea is to rebuild only the
34631 package that needs to be patched, and then to ``graft'' it onto packages
34632 explicitly installed by the user and that were previously referring to
34633 the original package. The cost of grafting is typically very low, and
34634 order of magnitudes lower than a full rebuild of the dependency chain.
34636 @cindex replacements of packages, for grafts
34637 For instance, suppose a security update needs to be applied to Bash.
34638 Guix developers will provide a package definition for the ``fixed''
34639 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
34640 Packages}). Then, the original package definition is augmented with a
34641 @code{replacement} field pointing to the package containing the bug fix:
34648 (replacement bash-fixed)))
34651 From there on, any package depending directly or indirectly on Bash---as
34652 reported by @command{guix gc --requisites} (@pxref{Invoking guix
34653 gc})---that is installed is automatically ``rewritten'' to refer to
34654 @code{bash-fixed} instead of @code{bash}. This grafting process takes
34655 time proportional to the size of the package, usually less than a
34656 minute for an ``average'' package on a recent machine. Grafting is
34657 recursive: when an indirect dependency requires grafting, then grafting
34658 ``propagates'' up to the package that the user is installing.
34660 Currently, the length of the name and version of the graft and that of
34661 the package it replaces (@code{bash-fixed} and @code{bash} in the example
34662 above) must be equal. This restriction mostly comes from the fact that
34663 grafting works by patching files, including binary files, directly.
34664 Other restrictions may apply: for instance, when adding a graft to a
34665 package providing a shared library, the original shared library and its
34666 replacement must have the same @code{SONAME} and be binary-compatible.
34668 The @option{--no-grafts} command-line option allows you to forcefully
34669 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
34673 guix build bash --no-grafts
34677 returns the store file name of the original Bash, whereas:
34684 returns the store file name of the ``fixed'', replacement Bash. This
34685 allows you to distinguish between the two variants of Bash.
34687 To verify which Bash your whole profile refers to, you can run
34688 (@pxref{Invoking guix gc}):
34691 guix gc -R $(readlink -f ~/.guix-profile) | grep bash
34695 @dots{} and compare the store file names that you get with those above.
34696 Likewise for a complete Guix system generation:
34699 guix gc -R $(guix system build my-config.scm) | grep bash
34702 Lastly, to check which Bash running processes are using, you can use the
34703 @command{lsof} command:
34706 lsof | grep /gnu/store/.*bash
34710 @node Bootstrapping
34711 @chapter Bootstrapping
34713 @c Adapted from the ELS 2013 paper.
34715 @cindex bootstrapping
34717 Bootstrapping in our context refers to how the distribution gets built
34718 ``from nothing''. Remember that the build environment of a derivation
34719 contains nothing but its declared inputs (@pxref{Introduction}). So
34720 there's an obvious chicken-and-egg problem: how does the first package
34721 get built? How does the first compiler get compiled?
34723 It is tempting to think of this question as one that only die-hard
34724 hackers may care about. However, while the answer to that question is
34725 technical in nature, its implications are wide-ranging. How the
34726 distribution is bootstrapped defines the extent to which we, as
34727 individuals and as a collective of users and hackers, can trust the
34728 software we run. It is a central concern from the standpoint of
34729 @emph{security} and from a @emph{user freedom} viewpoint.
34731 @cindex bootstrap binaries
34732 The GNU system is primarily made of C code, with libc at its core. The
34733 GNU build system itself assumes the availability of a Bourne shell and
34734 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
34735 `grep'. Furthermore, build programs---programs that run
34736 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
34737 (@pxref{Derivations}). Consequently, to be able to build anything at
34738 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
34739 Binutils, libc, and the other packages mentioned above---the
34740 @dfn{bootstrap binaries}.
34742 These bootstrap binaries are ``taken for granted'', though we can also
34743 re-create them if needed (@pxref{Preparing to Use the Bootstrap
34747 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
34748 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
34751 @node Reduced Binary Seed Bootstrap
34752 @section The Reduced Binary Seed Bootstrap
34754 Guix---like other GNU/Linux distributions---is traditionally bootstrapped from
34755 a set of bootstrap binaries: Bourne shell, command-line tools provided by GNU
34756 Coreutils, Awk, Findutils, `sed', and `grep' and Guile, GCC, Binutils, and the
34757 GNU C Library (@pxref{Bootstrapping}). Usually, these bootstrap binaries are
34758 ``taken for granted.''
34760 Taking the bootstrap binaries for granted means that we consider them to
34761 be a correct and trustworthy ``seed'' for building the complete system.
34762 Therein lies a problem: the combined size of these bootstrap binaries is
34763 about 250MB (@pxref{Bootstrappable Builds,,, mes, GNU Mes}). Auditing
34764 or even inspecting these is next to impossible.
34766 For @code{i686-linux} and @code{x86_64-linux}, Guix now features a
34767 ``Reduced Binary Seed'' bootstrap @footnote{We would like to say: ``Full
34768 Source Bootstrap'' and while we are working towards that goal it would
34769 be hyperbole to use that term for what we do now.}.
34771 The Reduced Binary Seed bootstrap removes the most critical tools---from a
34772 trust perspective---from the bootstrap binaries: GCC, Binutils and the GNU C
34773 Library are replaced by: @code{bootstrap-mescc-tools} (a tiny assembler and
34774 linker) and @code{bootstrap-mes} (a small Scheme Interpreter and a C compiler
34775 written in Scheme and the Mes C Library, built for TinyCC and for GCC).
34777 Using these new binary seeds the ``missing'' Binutils, GCC, and the GNU
34778 C Library are built from source. From here on the more traditional
34779 bootstrap process resumes. This approach has reduced the bootstrap
34780 binaries in size to about 145MB in Guix v1.1.
34782 The next step that Guix has taken is to replace the shell and all its
34783 utilities with implementations in Guile Scheme, the @emph{Scheme-only
34784 bootstrap}. Gash (@pxref{Gash,,, gash, The Gash manual}) is a
34785 POSIX-compatible shell that replaces Bash, and it comes with Gash Utils
34786 which has minimalist replacements for Awk, the GNU Core Utilities, Grep,
34787 Gzip, Sed, and Tar. The rest of the bootstrap binary seeds that were
34788 removed are now built from source.
34790 Building the GNU System from source is currently only possible by adding
34791 some historical GNU packages as intermediate steps@footnote{Packages
34792 such as @code{gcc-2.95.3}, @code{binutils-2.14}, @code{glibc-2.2.5},
34793 @code{gzip-1.2.4}, @code{tar-1.22}, and some others. For details, see
34794 @file{gnu/packages/commencement.scm}.}. As Gash and Gash Utils mature,
34795 and GNU packages become more bootstrappable again (e.g., new releases of
34796 GNU Sed will also ship as gzipped tarballs again, as alternative to the
34797 hard to bootstrap @code{xz}-compression), this set of added packages can
34798 hopefully be reduced again.
34800 The graph below shows the resulting dependency graph for
34801 @code{gcc-core-mesboot0}, the bootstrap compiler used for the
34802 traditional bootstrap of the rest of the Guix System.
34804 @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
34805 @image{images/gcc-core-mesboot0-graph,6in,,Dependency graph of gcc-core-mesboot0}
34807 The only significant binary bootstrap seeds that remain@footnote{
34808 Ignoring the 68KB @code{mescc-tools}; that will be removed later,
34809 together with @code{mes}.} are a Scheme interpreter and a Scheme
34810 compiler: GNU Mes and GNU Guile@footnote{Not shown in this graph are the
34811 static binaries for @file{bash}, @code{tar}, and @code{xz} that are used
34812 to get Guile running.}.
34814 This further reduction has brought down the size of the binary seed to
34815 about 60MB for @code{i686-linux} and @code{x86_64-linux}.
34817 Work is ongoing to remove all binary blobs from our free software
34818 bootstrap stack, working towards a Full Source Bootstrap. Also ongoing
34819 is work to bring these bootstraps to the @code{arm-linux} and
34820 @code{aarch64-linux} architectures and to the Hurd.
34822 If you are interested, join us on @samp{#bootstrappable} on the Freenode
34823 IRC network or discuss on @email{bug-mes@@gnu.org} or
34824 @email{gash-devel@@nongnu.org}.
34826 @node Preparing to Use the Bootstrap Binaries
34827 @section Preparing to Use the Bootstrap Binaries
34829 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
34830 @c large image, it's hard to scroll. Oh well.
34831 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
34833 The figure above shows the very beginning of the dependency graph of the
34834 distribution, corresponding to the package definitions of the @code{(gnu
34835 packages bootstrap)} module. A similar figure can be generated with
34836 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
34839 guix graph -t derivation \
34840 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
34841 | dot -Tps > gcc.ps
34844 or, for the further Reduced Binary Seed bootstrap
34847 guix graph -t derivation \
34848 -e '(@@@@ (gnu packages bootstrap) %bootstrap-mes)' \
34849 | dot -Tps > mes.ps
34852 At this level of detail, things are
34853 slightly complex. First, Guile itself consists of an ELF executable,
34854 along with many source and compiled Scheme files that are dynamically
34855 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
34856 tarball shown in this graph. This tarball is part of Guix's ``source''
34857 distribution, and gets inserted into the store with @code{add-to-store}
34858 (@pxref{The Store}).
34860 But how do we write a derivation that unpacks this tarball and adds it
34861 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
34862 derivation---the first one that gets built---uses @code{bash} as its
34863 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
34864 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
34865 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
34866 the Guix source distribution, whose sole purpose is to allow the Guile
34867 tarball to be unpacked.
34869 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
34870 Guile that can be used to run subsequent build programs. Its first task
34871 is to download tarballs containing the other pre-built binaries---this
34872 is what the @file{.tar.xz.drv} derivations do. Guix modules such as
34873 @code{ftp-client.scm} are used for this purpose. The
34874 @code{module-import.drv} derivations import those modules in a directory
34875 in the store, using the original layout. The
34876 @code{module-import-compiled.drv} derivations compile those modules, and
34877 write them in an output directory with the right layout. This
34878 corresponds to the @code{#:modules} argument of
34879 @code{build-expression->derivation} (@pxref{Derivations}).
34881 Finally, the various tarballs are unpacked by the derivations
34882 @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv}, or
34883 @code{bootstrap-mes-0.drv} and @code{bootstrap-mescc-tools-0.drv}, at which
34884 point we have a working C tool chain.
34886 @unnumberedsec Building the Build Tools
34888 Bootstrapping is complete when we have a full tool chain that does not
34889 depend on the pre-built bootstrap tools discussed above. This
34890 no-dependency requirement is verified by checking whether the files of
34891 the final tool chain contain references to the @file{/gnu/store}
34892 directories of the bootstrap inputs. The process that leads to this
34893 ``final'' tool chain is described by the package definitions found in
34894 the @code{(gnu packages commencement)} module.
34896 The @command{guix graph} command allows us to ``zoom out'' compared to
34897 the graph above, by looking at the level of package objects instead of
34898 individual derivations---remember that a package may translate to
34899 several derivations, typically one derivation to download its source,
34900 one to build the Guile modules it needs, and one to actually build the
34901 package from source. The command:
34904 guix graph -t bag \
34905 -e '(@@@@ (gnu packages commencement)
34906 glibc-final-with-bootstrap-bash)' | xdot -
34910 displays the dependency graph leading to the ``final'' C
34911 library@footnote{You may notice the @code{glibc-intermediate} label,
34912 suggesting that it is not @emph{quite} final, but as a good
34913 approximation, we will consider it final.}, depicted below.
34915 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
34917 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
34918 The first tool that gets built with the bootstrap binaries is
34919 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
34920 for all the following packages. From there Findutils and Diffutils get
34923 Then come the first-stage Binutils and GCC, built as pseudo cross
34924 tools---i.e., with @option{--target} equal to @option{--host}. They are
34925 used to build libc. Thanks to this cross-build trick, this libc is
34926 guaranteed not to hold any reference to the initial tool chain.
34928 From there the final Binutils and GCC (not shown above) are built. GCC
34929 uses @command{ld} from the final Binutils, and links programs against
34930 the just-built libc. This tool chain is used to build the other
34931 packages used by Guix and by the GNU Build System: Guile, Bash,
34934 And voilà! At this point we have the complete set of build tools that
34935 the GNU Build System expects. These are in the @code{%final-inputs}
34936 variable of the @code{(gnu packages commencement)} module, and are
34937 implicitly used by any package that uses @code{gnu-build-system}
34938 (@pxref{Build Systems, @code{gnu-build-system}}).
34941 @unnumberedsec Building the Bootstrap Binaries
34943 @cindex bootstrap binaries
34944 Because the final tool chain does not depend on the bootstrap binaries,
34945 those rarely need to be updated. Nevertheless, it is useful to have an
34946 automated way to produce them, should an update occur, and this is what
34947 the @code{(gnu packages make-bootstrap)} module provides.
34949 The following command builds the tarballs containing the bootstrap binaries
34950 (Binutils, GCC, glibc, for the traditional bootstrap and linux-libre-headers,
34951 bootstrap-mescc-tools, bootstrap-mes for the Reduced Binary Seed bootstrap,
34952 and Guile, and a tarball containing a mixture of Coreutils and other basic
34953 command-line tools):
34956 guix build bootstrap-tarballs
34959 The generated tarballs are those that should be referred to in the
34960 @code{(gnu packages bootstrap)} module mentioned at the beginning of
34963 Still here? Then perhaps by now you've started to wonder: when do we
34964 reach a fixed point? That is an interesting question! The answer is
34965 unknown, but if you would like to investigate further (and have
34966 significant computational and storage resources to do so), then let us
34969 @unnumberedsec Reducing the Set of Bootstrap Binaries
34971 Our traditional bootstrap includes GCC, GNU Libc, Guile, etc. That's a lot of
34972 binary code! Why is that a problem? It's a problem because these big chunks
34973 of binary code are practically non-auditable, which makes it hard to establish
34974 what source code produced them. Every unauditable binary also leaves us
34975 vulnerable to compiler backdoors as described by Ken Thompson in the 1984
34976 paper @emph{Reflections on Trusting Trust}.
34978 This is mitigated by the fact that our bootstrap binaries were generated
34979 from an earlier Guix revision. Nevertheless it lacks the level of
34980 transparency that we get in the rest of the package dependency graph,
34981 where Guix always gives us a source-to-binary mapping. Thus, our goal
34982 is to reduce the set of bootstrap binaries to the bare minimum.
34984 The @uref{https://bootstrappable.org, Bootstrappable.org web site} lists
34985 on-going projects to do that. One of these is about replacing the
34986 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
34987 of increasing complexity, which could be built from source starting from
34988 a simple and auditable assembler.
34990 Our first major achievement is the replacement of of GCC, the GNU C Library
34991 and Binutils by MesCC-Tools (a simple hex linker and macro assembler) and Mes
34992 (@pxref{Top, GNU Mes Reference Manual,, mes, GNU Mes}, a Scheme interpreter
34993 and C compiler in Scheme). Neither MesCC-Tools nor Mes can be fully
34994 bootstrapped yet and thus we inject them as binary seeds. We call this the
34995 Reduced Binary Seed bootstrap, as it has halved the size of our bootstrap
34996 binaries! Also, it has eliminated the C compiler binary; i686-linux and
34997 x86_64-linux Guix packages are now bootstrapped without any binary C compiler.
34999 Work is ongoing to make MesCC-Tools and Mes fully bootstrappable and we are
35000 also looking at any other bootstrap binaries. Your help is welcome!
35003 @chapter Porting to a New Platform
35005 As discussed above, the GNU distribution is self-contained, and
35006 self-containment is achieved by relying on pre-built ``bootstrap
35007 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
35008 operating system kernel, CPU architecture, and application binary
35009 interface (ABI). Thus, to port the distribution to a platform that is
35010 not yet supported, one must build those bootstrap binaries, and update
35011 the @code{(gnu packages bootstrap)} module to use them on that platform.
35013 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
35014 When everything goes well, and assuming the GNU tool chain supports the
35015 target platform, this can be as simple as running a command like this
35019 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
35022 For this to work, the @code{glibc-dynamic-linker} procedure in
35023 @code{(gnu packages bootstrap)} must be augmented to return the right
35024 file name for libc's dynamic linker on that platform; likewise,
35025 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
35026 taught about the new platform.
35028 Once these are built, the @code{(gnu packages bootstrap)} module needs
35029 to be updated to refer to these binaries on the target platform. That
35030 is, the hashes and URLs of the bootstrap tarballs for the new platform
35031 must be added alongside those of the currently supported platforms. The
35032 bootstrap Guile tarball is treated specially: it is expected to be
35033 available locally, and @file{gnu/local.mk} has rules to download it for
35034 the supported architectures; a rule for the new platform must be added
35037 In practice, there may be some complications. First, it may be that the
35038 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
35039 above) is not recognized by all the GNU tools. Typically, glibc
35040 recognizes some of these, whereas GCC uses an extra @option{--with-abi}
35041 configure flag (see @code{gcc.scm} for examples of how to handle this).
35042 Second, some of the required packages could fail to build for that
35043 platform. Lastly, the generated binaries could be broken for some
35046 @c *********************************************************************
35047 @include contributing.texi
35049 @c *********************************************************************
35050 @node Acknowledgments
35051 @chapter Acknowledgments
35053 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
35054 which was designed and
35055 implemented by Eelco Dolstra, with contributions from other people (see
35056 the @file{nix/AUTHORS} file in Guix). Nix pioneered functional package
35057 management, and promoted unprecedented features, such as transactional
35058 package upgrades and rollbacks, per-user profiles, and referentially
35059 transparent build processes. Without this work, Guix would not exist.
35061 The Nix-based software distributions, Nixpkgs and NixOS, have also been
35062 an inspiration for Guix.
35064 GNU@tie{}Guix itself is a collective work with contributions from a
35065 number of people. See the @file{AUTHORS} file in Guix for more
35066 information on these fine people. The @file{THANKS} file lists people
35067 who have helped by reporting bugs, taking care of the infrastructure,
35068 providing artwork and themes, making suggestions, and more---thank you!
35071 @c *********************************************************************
35072 @node GNU Free Documentation License
35073 @appendix GNU Free Documentation License
35074 @cindex license, GNU Free Documentation License
35075 @include fdl-1.3.texi
35077 @c *********************************************************************
35078 @node Concept Index
35079 @unnumbered Concept Index
35082 @node Programming Index
35083 @unnumbered Programming Index
35084 @syncodeindex tp fn
35085 @syncodeindex vr fn
35090 @c Local Variables:
35091 @c ispell-local-dictionary: "american";