Toggle diff (538 lines)
diff --git a/Makefile.am b/Makefile.am
index 8df8222573..502ca73866 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -533,6 +533,7 @@ SCM_TESTS = \
tests/services.scm \
tests/services/file-sharing.scm \
tests/services/configuration.scm \
+ tests/services/lightdm.scm \
tests/services/linux.scm \
tests/services/telephony.scm \
tests/sets.scm \
diff --git a/doc/guix.texi b/doc/guix.texi
index 039df29ebc..596bb15288 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -21267,6 +21267,208 @@ Relogin after logout.
@end table
@end deftp
+@cindex lightdm, graphical login manager
+@cindex display manager, lightdm
+@defvr {Scheme Variable} lightdm-service-type
+This is the type of the service to run the
+@url{https://github.com/canonical/lightdm,LightDM display manager}. Its
+value must be a @code{lightdm-configuration} record, which is documented
+below. Among its distinguishing features are TigerVNC integration for
+easily remoting your desktop as well as support for the XDMCP protocol,
+which can be used by remote clients to start a session from the login
+manager.
+
+In its most basic form, it can be used simply as:
+
+@lisp
+(service lightdm-service-type)
+@end lisp
+
+A more elaborate example making use of the VNC capabilities and enabling
+more features and verbose logs could look like:
+
+@lisp
+(service lightdm-service-type
+ (lightdm-configuration
+ (allow-empty-passwords? #t)
+ (xdmcp? #t)
+ (vnc-server? #t)
+ (vnc-server-command
+ (file-append tigervnc-server "/bin/Xvnc"
+ " -SecurityTypes None"))
+ (seats
+ (list (lightdm-seat-configuration
+ (name "*")
+ (user-session "ratpoison"))))))
+@end lisp
+@end defvr
+
+@c The LightDM service documentation can be auto-generated via the
+@c 'generate-doc' procedure at the bottom of the (gnu services lightdm)
+@c module.
+@c %start of fragment
+@deftp {Data Type} lightdm-configuration
+Available @code{lightdm-configuration} fields are:
+
+@table @asis
+@item @code{lightdm} (default: @code{lightdm}) (type: file-like)
+The lightdm package to use.
+
+@item @code{allow-empty-passwords?} (default: @code{#f}) (type: boolean)
+Whether users not having a password set can login.
+
+@item @code{debug?} (default: @code{#f}) (type: boolean)
+Enable verbose output.
+
+@item @code{xorg-configuration} (type: xorg-configuration)
+The default Xorg server configuration to use to generate the Xorg server
+start script. It can be refined per seat via the @code{xserver-command}
+of the @code{<lightdm-seat-configuration>} record, if desired.
+
+@item @code{greeters} (type: list-of-greeter-configurations)
+The LightDM greeter configurations specifying the greeters to use.
+
+@item @code{seats} (type: list-of-seat-configurations)
+The seat configurations to use. A LightDM seat is akin to a user.
+
+@item @code{xdmcp?} (default: @code{#f}) (type: boolean)
+Whether a XDMCP server should listen on port UDP 177.
+
+@item @code{xdmcp-listen-address} (type: maybe-string)
+The host or IP address the XDMCP server listens for incoming
+connections. When unspecified, listen on for any hosts/IP addresses.
+
+@item @code{vnc-server?} (default: @code{#f}) (type: boolean)
+Whether a VNC server is started.
+
+@item @code{vnc-server-command} (type: file-like)
+The Xvnc command to use for the VNC server, it's possible to provide
+extra options not otherwise exposed along the command, for example to
+disable security:
+
+@lisp
+(vnc-server-command (file-append tigervnc-server "/bin/Xvnc"
+ " -SecurityTypes None" ))
+@end lisp
+
+Or to set a PasswordFile for the classic (unsecure) VncAuth
+mecanism:
+
+@lisp
+(vnc-server-command (file-append tigervnc-server "/bin/Xvnc"
+ " -PasswordFile /var/lib/lightdm/.vnc/passwd"))
+@end lisp
+
+The password file should be manually created using the
+@command{vncpasswd} command. Note that LightDM will create new sessions
+for VNC users, which means they need to authenticate in the same way as
+local users would.
+
+@item @code{vnc-server-listen-address} (type: maybe-string)
+The host or IP address the VNC server listens for incoming connections.
+When unspecified, listen for any hosts/IP addresses.
+
+@item @code{vnc-server-port} (default: @code{5900}) (type: number)
+The TCP port the VNC server should listen to.
+
+@item @code{extra-config} (default: @code{()}) (type: list-of-strings)
+Extra configuration values to append to the LightDM configuration file.
+
+@end table
+@end deftp
+
+
+@c %end of fragment
+@c %start of fragment
+
+@deftp {Data Type} lightdm-gtk-greeter-configuration
+Available @code{lightdm-gtk-greeter-configuration} fields are:
+
+@table @asis
+@item @code{lightdm-gtk-greeter} (default: @code{lightdm-gtk-greeter}) (type: file-like)
+The lightdm-gtk-greeter package to use.
+
+@item @code{assets} @
+(default: @code{(adwaita-icon-theme gnome-themes-extrahicolor-icon-theme)}) @
+(type: list-of-file-likes)
+The list of packages complementing the greeter, such as package
+providing icon themes.
+
+@item @code{theme-name} (default: @code{"Adwaita"}) (type: string)
+The name of the theme to use.
+
+@item @code{icon-theme-name} (default: @code{"Adwaita"}) (type: string)
+The name of the icon theme to use.
+
+@item @code{cursor-theme-name} (default: @code{"Adwaita"}) (type: string)
+The name of the cursor theme to use.
+
+@item @code{cursor-theme-size} (default: @code{16}) (type: number)
+The size to use for the the cursor theme.
+
+@item @code{allow-debugging?} (type: maybe-boolean)
+Set to #t to enable debug log level.
+
+@item @code{background} (type: file-like)
+The background image to use.
+
+@item @code{at-spi-enabled?} (default: @code{#f}) (type: boolean)
+Enable accessibility support through the Assistive Technology Service
+Provider Interface (AT-SPI).
+
+@item @code{a11y-states} @
+(default: @code{(contrast font keyboard reader)}) (type: list-of-a11y-states)
+The accessibility features to enable, given as list of symbols.
+
+@item @code{reader} (type: maybe-file-like)
+The command to use to launch a screen reader.
+
+@item @code{extra-config} (default: @code{()}) (type: list-of-strings)
+Extra configuration values to append to the LightDM GTK Greeter
+configuration file.
+
+@end table
+@end deftp
+
+@c %end of fragment
+@c %start of fragment
+
+@deftp {Data Type} lightdm-seat-configuration
+Available @code{lightdm-seat-configuration} fields are:
+
+@table @asis
+@item @code{name} (type: seat-name)
+The name of the seat. An asterisk (*) can be used in the name to apply
+the seat configuration to all the seat names it matches.
+
+@item @code{user-session} (type: maybe-string)
+The session to use by default. The session name must be provided as a
+lowercase string, such as @code{"gnome"}, @code{"ratpoison"}, etc.
+
+@item @code{type} (default: @code{local}) (type: seat-type)
+The type of the seat, either the @code{local} or @code{xremote} symbol.
+
+@item @code{autologin-user} (type: maybe-string)
+The username to automatically log in with by default.
+
+@item @code{greeter-session} @
+(default: @code{lightdm-gtk-greeter}) (type: greeter-session)
+The greeter session to use, specified as a symbol. Currently, only
+@code{lightdm-gtk-greeter} is supported.
+
+@item @code{xserver-command} (type: maybe-file-like)
+The Xorg server command to run.
+
+@item @code{session-wrapper} (type: file-like)
+The xinitrc session wrapper to use.
+
+@item @code{extra-config} (default: @code{()}) (type: list-of-strings)
+Extra configuration values to append to the seat configuration section.
+
+@end table
+@end deftp
+@c %end of fragment
+
@cindex Xorg, configuration
@deftp {Data Type} xorg-configuration
diff --git a/gnu/local.mk b/gnu/local.mk
index e0c6d6fba1..69847cdfc2 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -660,6 +660,7 @@ GNU_SYSTEM_MODULES = \
%D%/services/guix.scm \
%D%/services/hurd.scm \
%D%/services/kerberos.scm \
+ %D%/services/lightdm.scm \
%D%/services/linux.scm \
%D%/services/lirc.scm \
%D%/services/virtualization.scm \
diff --git a/gnu/services/lightdm.scm b/gnu/services/lightdm.scm
new file mode 100644
index 0000000000..07f2e808dd
--- /dev/null
+++ b/gnu/services/lightdm.scm
@@ -0,0 +1,687 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2019, 2020 L p R n d n <guix@lprndn.info>
+;;; Copyright © 2020 Ricardo Wurmus <rekado@elephly.net>
+;;; Copyright © 2022 Maxim Cournoyer <maxim.cournoyer@gmail.com>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; GNU Guix is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (gnu services lightdm)
+ #:use-module (gnu artwork)
+ #:use-module (gnu packages admin)
+ #:use-module (gnu packages display-managers)
+ #:use-module (gnu packages freedesktop)
+ #:use-module (gnu packages gnome)
+ #:use-module (gnu packages vnc)
+ #:use-module (gnu packages xorg)
+ #:use-module (gnu services configuration)
+ #:use-module (gnu services dbus)
+ #:use-module (gnu services desktop)
+ #:use-module (gnu services shepherd)
+ #:use-module (gnu services xorg)
+ #:use-module (gnu services)
+ #:use-module (gnu system pam)
+ #:use-module (gnu system shadow)
+ #:use-module (guix diagnostics)
+ #:use-module (guix gexp)
+ #:use-module (guix i18n)
+ #:use-module (guix records)
+ #:use-module (ice-9 format)
+ #:use-module (ice-9 match)
+ #:use-module (oop goops)
+ #:use-module (srfi srfi-1)
+ #:use-module (srfi srfi-26)
+ #:export (lightdm-seat-configuration
+ lightdm-seat-configuration?
+ lightdm-seat-configuration-name
+ lightdm-seat-configuration-type
+ lightdm-seat-configuration-user-session
+ lightdm-seat-configuration-autologin-user
+ lightdm-seat-configuration-greeter-session
+ lightdm-seat-configuration-xserver-command
+ lightdm-seat-configuration-session-wrapper
+ lightdm-seat-configuration-extra-config
+
+ lightdm-gtk-greeter-configuration
+ lightdm-gtk-greeter-configuration?
+ lightdm-gtk-greeter-configuration-lightdm-gtk-greeter
+ lightdm-gtk-greeter-configuration-assets
+ lightdm-gtk-greeter-configuration-theme-name
+ lightdm-gtk-greeter-configuration-icon-theme-name
+ lightdm-gtk-greeter-configuration-cursor-theme-name
+ lightdm-gtk-greeter-configuration-allow-debug
+ lightdm-gtk-greeter-configuration-background
+ lightdm-gtk-greeter-configuration-a11y-states
+ lightdm-gtk-greeter-configuration-reader
+ lightdm-gtk-greeter-configuration-extra-config
+
+ lightdm-configuration
+ lightdm-configuration?
+ lightdm-configuration-lightdm
+ lightdm-configuration-allow-empty-passwords?
+ lightdm-configuration-xorg-configuration
+ lightdm-configuration-greeters
+ lightdm-configuration-seats
+ lightdm-configuration-xdmcp?
+ lightdm-configuration-xdmcp-listen-address
+ lightdm-configuration-vnc-server?
+ lightdm-configuration-vnc-server-command
+ lightdm-configuration-vnc-server-listen-address
+ lightdm-configuration-vnc-server-port
+ lightdm-configuration-extra-config
+
+ lightdm-service-type))
+
+;;;
+;;; Greeters.
+;;;
+
+(define list-of-file-likes?
+ (list-of file-like?))
+
+(define %a11y-states '(contrast font keyboard reader))
+
+(define (a11y-state? value)
+ (memq value %a11y-states))
+
+(define list-of-a11y-states?
+ (list-of a11y-state?))
+
+(define-maybe boolean)
+
+(define (serialize-boolean name value)
+ (define (strip-trailing-? name)
+ ;; field? -> field
+ (let ((str (symbol->string name)))
+ (if (string-suffix? "?" str)
+ (string-drop-right str 1)
+ str)))
+ (format #f "~a=~:[false~;true~]~%" (strip-trailing-? name) value))
+
+(define-maybe file-like)
+
+(define (serialize-file-like name value)
+ #~(format #f "~a=~a~%" '#$name #$value))
+
+(define (serialize-list-of-a11y-states name value)
+ (format #f "~a=~a~%" name (string-join (map symbol->string value) ";")))
+
+(define (serialize-string name value)
+ (format #f "~a=~a~%" name value))
+
+(define (serialize-number name value)
+ (format #f "~a=~a~%" name value))
+
+(define (serialize-list-of-strings _ value)
+ (string-join value "\n"))
+
+(define-configuration lightdm-gtk-greeter-configuration
+ (lightdm-gtk-greeter
+ (file-like lightdm-gtk-greeter)
+ "The lightdm-gtk-greeter package to use."
+ empty-serializer)
+ (assets
+ (list-of-file-likes (list adwaita-icon-theme
+ gnome-themes-extra
+ ;; FIXME: hicolor-icon-theme should be in the
+ ;; packages of the desktop templates.
+ hicolor-icon-theme))
+ "The list of packages complementing the greeter, such as package providing
+icon themes."
+ empty-serializer)
+ (theme-name
+ (string "Adwaita")
+ "The name of the theme to use.")
+ (icon-theme-name
+ (string "Adwaita")
+ "The name of the icon theme to use.")
+ (cursor-theme-name
+ (string "Adwaita")
+ "The name of the cursor theme to use.")
+ (cursor-theme-size
+ (number 16)
+ "The size to use for the the cursor theme.")
+ (allow-debugging?
+ maybe-boolean
+ "Set to #t to enable debug log level.")
+ (background
+ (file-like (file-append %artwork-repository
+ "/backgrounds/guix-checkered-16-9.svg"))
+ "The background image to use.")
+ ;; FIXME: This should be enabled by default, but it currently doesn't work,
+ ;; failing to connect to D-Bus, causing the login to fail.
+ (at-spi-enabled?
+ (boolean #f)
+ "Enable accessibility support through the Assistive Technology Service
+Provider Interface (AT-SPI).")
+ (a11y-states
+ (list-of-a11y-states %a11y-states)
+ "The accessibility features to enable, given as list of symbols.")
+ (reader
+ maybe-file-like
+ "The command to use to launch a screen reader.")
+ (extra-config
+ (list-of-strings '())
+ "Extra configuration values to append to the LightDM GTK Greeter
+configuration file."))
+
+(define (strip-class-name-brackets name)
+ "Remove the '<<' and '>>' brackets from NAME, a symbol."
+ (let ((name* (symbol->string name)))
+ (if (and (string-prefix? "<<" name*)
+ (string-suffix? ">>" name*))
+ (string->symbol (string-drop (string-drop-right name* 2) 2))
+ (error "unexpected class name" name*))))
+
+(define (config->name config)
+ "Return the constructor name (a symbol) from CONFIG."
+ (strip-class-name-brackets (class-name (class-of config))))
+
+(define (greeter-configuration->greeter-fields config)
+ "Return the fields of CONFIG, a greeter configuration."
+ (match config
+ ;; Note: register any new greeter configuration here.
+ ((? lightdm-gtk-greeter-configuration?)
+ lightdm-gtk-greeter-configuration-fields)))
+
+(define (greeter-configuration->packages config)
+ "Return the list of greeter packages, including assets, used by CONFIG, a
+greeter configuration."
+ (match config
+ ;; Note: register any new greeter configuration here.
+ ((? lightdm-gtk-greeter-configuration?)
+ (cons (lightdm-gtk-greeter-configuration-lightdm-gtk-greeter config)
+ (lightdm-gtk-greeter-configuration-assets config)))))
+
+;;; TODO: Implement directly in (gnu services configuration), perhaps by
+;;; making the FIELDS argument optional.
+(define (serialize-configuration* config)
+ "Like `serialize-configuration', but not requiring to provide a FIELDS
+argument."
+ (define fields (greeter-configuration->greeter-fields config))
+ (serialize-configuration config fields))
+
+(define (greeter-configuration->conf-name config)
+ "Return the file name of CONFIG, a greeter configuration."
+ (format #f "~a.conf" (greeter-configuration->greeter-session config)))
+
+(define (greeter-configuration->file config)
+ "Serialize CONFIG into a file under the output directory, so that it can be
+easily added to XDG_CONF_DIRS."
+ (computed-file
+ (greeter-configuration->conf-name config)
+ #~(begin
+ (call-with-output-file #$output
+ (lambda (port)
+ (format port (string-append
+ "[greeter]\n"
+ #$(serialize-configuration* config))))))))
+
+
+;;;
+;;; Seats.
+;;;
+
+(define seat-name? string?)
+
+(define (serialize-seat-name _ value)
+ (format #f "[Seat:~a]~%" value))
+
+(define (seat-type? type)
+ (memq type '(local xremote)))
+
+(define (serialize-seat-type name value)
+ (format #f "~a=~a~%" name value))
+
+(define-maybe seat-type)
+
+(define (greeter-session? value)
+ (memq value '(lightdm-gtk-greeter)))
+
+(define (serialize-greeter-session name value)
+ (format #f "~a=~a~%" name value))
+
+(define-maybe greeter-session)
+
+(define-maybe string)
+
+;;; Note: all the fields except for the seat name should be 'maybe's, since
+;;; the real default value is set by the %lightdm-seat-default define later,
+;;; and this avoids repeating ourselves in the serialized configuration file.
+(define-configuration lightdm-seat-configuration
+ (name
+ seat-name
+ "The name of the seat. An asterisk (*) can be used in the name
+to apply the seat configuration to all the seat names it matches.")
+ (user-session
+ maybe-string
+ "The session to use by default. The session name must be provided as a
+lowercase string, such as @code{\"gnome\"}, @code{\"ratpoison\"}, etc.")
+ (type
+ (seat-type 'local)
+ "The type of the seat, either the @code{local} or @code{xremote} symbol.")
+ (autologin-user
+ maybe-string
+ "The username to automatically log in with by default.")
+ (greeter-session
+ (greeter-session 'lightdm-gtk-greeter)
+ "The greeter session to use, specified as a symbol. Currently, only
+@code{lightdm-gtk-greeter} is supported.")
+ ;; Note: xserver-command must be lazily computed, so that it can be
+ ;; overridden via 'lightdm-configuration-xorg-configuration'.
+ (xserver-command
+ maybe-file-like
+ "The Xorg server command to run.")
+ (session-wrapper
+ (file-like (xinitrc))
+ "The xinitrc session wrapper to use.")
+ (extra-config
+ (list-of-strings '())
+ "Extra configuration values to append to the seat configuration section."))
+
+(define (greeter-session->greater-configuration-pred identifier)
+ "Return the predicate to che
