services: Add lightdm-service-type.

* gnu/services/lightdm.scm: New service.
* tests/services/lightdm.scm: Test it.
* doc/guix.texi (X Window): Document it.
* gnu/local.mk (GNU_SYSTEM_MODULES): Register it.

Co-authored-by: L p R n d n <guix@lprndn.info>
Co-authored-by: Ricardo Wurmus <rekado@elephly.net>
This commit is contained in:
Maxim Cournoyer 2022-08-03 23:41:35 -04:00
parent 42fee6d0f1
commit 0ea62e84a7
No known key found for this signature in database
GPG Key ID: 1260E46482E63562
6 changed files with 1103 additions and 0 deletions

@ -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 \

@ -21278,6 +21278,208 @@ 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

@ -661,6 +661,7 @@ 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 \

687
gnu/services/lightdm.scm Normal file

@ -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 check if a configuration is of the type specifying
a greeter identified by IDENTIFIER."
(match identifier
;; Note: register any new greeter identifier here.
('lightdm-gtk-greeter
lightdm-gtk-greeter-configuration?)))
(define (greeter-configuration->greeter-session config)
"Given CONFIG, a greeter configuration object, return its identifier,
a symbol."
(let ((suffix "-configuration")
(greeter-conf-name (config->name config)))
(string->symbol (string-drop-right (symbol->string greeter-conf-name)
(string-length suffix)))))
(define list-of-seat-configurations?
(list-of lightdm-seat-configuration?))
;;;
;;; LightDM.
;;;
(define (greeter-configuration? config)
(or (lightdm-gtk-greeter-configuration? config)
;; Note: register any new greeter configuration here.
))
(define (list-of-greeter-configurations? greeter-configs)
(and ((list-of greeter-configuration?) greeter-configs)
;; Greeter configurations must also not be provided more than once.
(let* ((types (map (cut (compose class-name class-of) <>)
greeter-configs))
(dupes (filter (lambda (type)
(< 1 (count (cut eq? type <>) types)))
types)))
(unless (null? dupes)
(leave (G_ "duplicate greeter configurations: ~a~%") dupes)))))
(define-configuration/no-serialization lightdm-configuration
(lightdm
(file-like lightdm)
"The lightdm package to use.")
(allow-empty-passwords?
(boolean #f)
"Whether users not having a password set can login.")
(debug?
(boolean #f)
"Enable verbose output.")
(xorg-configuration
(xorg-configuration (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.")
(greeters
(list-of-greeter-configurations (list (lightdm-gtk-greeter-configuration)))
"The LightDM greeter configurations specifying the greeters to use.")
(seats
(list-of-seat-configurations (list (lightdm-seat-configuration
(name "*"))))
"The seat configurations to use. A LightDM seat is akin to a user.")
(xdmcp?
(boolean #f)
"Whether a XDMCP server should listen on port UDP 177.")
(xdmcp-listen-address
maybe-string
"The host or IP address the XDMCP server listens for incoming connections.
When unspecified, listen on for any hosts/IP addresses.")
(vnc-server?
(boolean #f)
"Whether a VNC server is started.")
(vnc-server-command
(file-like (file-append tigervnc-server "bin/Xvnc"))
"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.
")
(vnc-server-listen-address
maybe-string
"The host or IP address the VNC server listens for incoming connections.
When unspecified, listen for any hosts/IP addresses.")
(vnc-server-port
(number 5900)
"The TCP port the VNC server should listen to.")
(extra-config
(list-of-strings '())
"Extra configuration values to append to the LightDM configuration file."))
(define (lightdm-configuration->greeters-config-dir config)
"Return a directory containing all the serialized greeter configurations
from CONFIG, a <lightdm-configuration> object."
(file-union "etc-lightdm"
(append-map (lambda (g)
`((,(greeter-configuration->conf-name g)
,(greeter-configuration->file g))))
(lightdm-configuration-greeters config))))
(define (lightdm-configuration->packages config)
"Return all the greeter packages and their assets defined in CONFIG, a
<lightdm-configuration> object, as well as the lightdm package itself."
(cons (lightdm-configuration-lightdm config)
(append-map greeter-configuration->packages
(lightdm-configuration-greeters config))))
(define (validate-lightdm-configuration config)
"Sanity check CONFIG, a <lightdm-configuration> record instance."
;; This is required to make inter-field validations, such as between the
;; seats and greeters.
(let* ((seats (lightdm-configuration-seats config))
(greeter-sessions (delete-duplicates
(map lightdm-seat-configuration-greeter-session
seats)
eq?))
(greeter-configurations (lightdm-configuration-greeters config))
(missing-greeters
(filter-map
(lambda (id)
(define pred (greeter-session->greater-configuration-pred id))
(if (find pred greeter-configurations)
#f ;happy path
id))
greeter-sessions)))
(unless (null? missing-greeters)
(leave (G_ "no greeter configured for seat greeter sessions: ~a~%")
missing-greeters))))
(define (lightdm-configuration-file config)
(match-record config <lightdm-configuration>
(xorg-configuration seats
xdmcp? xdmcp-listen-address
vnc-server? vnc-server-command vnc-server-listen-address vnc-server-port
extra-config)
(apply
mixed-text-file
"lightdm.conf" "
#
# General configuration
#
[LightDM]
greeter-user=lightdm
sessions-directory=/run/current-system/profile/share/xsessions\
:/run/current-system/profile/share/wayland-sessions
remote-sessions-directory=/run/current-system/profile/share/remote-sessions
"
#~(string-join '#$extra-config "\n")
"
#
# XDMCP Server configuration
#
[XDMCPServer]
enabled=" (if xdmcp? "true" "false") "\n"
(if (maybe-value-set? xdmcp-listen-address)
(format #f "xdmcp-listen-address=~a" xdmcp-listen-address)
"") "
#
# VNC Server configuration
#
[VNCServer]
enabled=" (if vnc-server? "true" "false") "
command=" vnc-server-command "
port=" (number->string vnc-server-port) "\n"
(if (maybe-value-set? vnc-server-listen-address)
(format #f "vnc-server-listen-address=~a" vnc-server-listen-address)
"") "
#
# Seat configuration.
#
"
(map (lambda (seat)
;; This complication exists to propagate a default value for
;; the 'xserver-command' field of the seats. Having a
;; 'xorg-configuration' field at the root of the
;; lightdm-configuration enables the use of
;; 'set-xorg-configuration' and can be more convenient.
(let ((seat* (if (maybe-value-set?
(lightdm-seat-configuration-xserver-command seat))
seat
(lightdm-seat-configuration
(inherit seat)
(xserver-command (xorg-start-command
xorg-configuration))))))
(serialize-configuration seat*
lightdm-seat-configuration-fields)))
seats))))
(define %lightdm-accounts
(list (user-group (name "lightdm") (system? #t))
(user-account
(name "lightdm")
(group "lightdm")
(system? #t)
(comment "LightDM user")
(home-directory "/var/lib/lightdm")
(shell (file-append shadow "/sbin/nologin")))))
(define %lightdm-activation
;; Ensure /var/lib/lightdm is owned by the "lightdm" user. Adapted from the
;; %gdm-activation.
(with-imported-modules '((guix build utils))
#~(begin
(use-modules (guix build utils))
(define (ensure-ownership directory)
(let* ((lightdm (getpwnam "lightdm"))
(uid (passwd:uid lightdm))
(gid (passwd:gid lightdm))
(st (stat directory #f)))
;; Recurse into directory only if it has wrong ownership.
(when (and st
(or (not (= uid (stat:uid st)))
(not (= gid (stat:gid st)))))
(for-each (lambda (file)
(chown file uid gid))
(find-files "directory"
#:directories? #t)))))
(when (not (stat "/var/lib/lightdm-data" #f))
(mkdir-p "/var/lib/lightdm-data"))
(for-each ensure-ownership
'("/var/lib/lightdm"
"/var/lib/lightdm-data")))))
(define (lightdm-pam-service config)
"Return a PAM service for @command{lightdm}."
(unix-pam-service "lightdm"
#:login-uid? #t
#:allow-empty-passwords?
(lightdm-configuration-allow-empty-passwords? config)))
(define (lightdm-greeter-pam-service)
"Return a PAM service for @command{lightdm-greeter}."
(pam-service
(name "lightdm-greeter")
(auth (list
;; Load environment from /etc/environment and ~/.pam_environment.
(pam-entry (control "required") (module "pam_env.so"))
;; Always let the greeter start without authentication.
(pam-entry (control "required") (module "pam_permit.so"))))
;; No action required for account management
(account (list (pam-entry (control "required") (module "pam_permit.so"))))
;; Prohibit changing password.
(password (list (pam-entry (control "required") (module "pam_deny.so"))))
;; Setup session.
(session (list (pam-entry (control "required") (module "pam_unix.so"))))))
(define (lightdm-autologin-pam-service)
"Return a PAM service for @command{lightdm-autologin}}."
(pam-service
(name "lightdm-autologin")
(auth
(list
;; Block login if user is globally disabled.
(pam-entry (control "required") (module "pam_nologin.so"))
(pam-entry (control "required") (module "pam_succeed_if.so")
(arguments (list "uid >= 1000")))
;; Allow access without authentication.
(pam-entry (control "required") (module "pam_permit.so"))))
;; Stop autologin if account requires action.
(account (list (pam-entry (control "required") (module "pam_unix.so"))))
;; Prohibit changing password.
(password (list (pam-entry (control "required") (module "pam_deny.so"))))
;; Setup session.
(session (list (pam-entry (control "required") (module "pam_unix.so"))))))
(define (lightdm-pam-services config)
(list (lightdm-pam-service config)
(lightdm-greeter-pam-service)
(lightdm-autologin-pam-service)))
(define (lightdm-shepherd-service config)
"Return a <lightdm-service> for LightDM using CONFIG."
(validate-lightdm-configuration config)
(define lightdm-command
#~(list #$(file-append (lightdm-configuration-lightdm config)
"/sbin/lightdm")
#$@(if (lightdm-configuration-debug? config)
#~("--debug")
#~())
"--config"
#$(lightdm-configuration-file config)))
(define lightdm-paths
(let ((lightdm (lightdm-configuration-lightdm config)))
#~(string-join
'#$(map (lambda (dir)
(file-append lightdm dir))
'("/bin" "/sbin" "/libexec"))
":")))
(define greeters-config-dir
(lightdm-configuration->greeters-config-dir config))
(define data-dirs
;; LightDM itself needs to be in XDG_DATA_DIRS for the accountsservice
;; interface it provides to be picked up. The greeters must also be in
;; XDG_DATA_DIRS to be found.
(let ((packages (lightdm-configuration->packages config)))
#~(string-join '#$(map (cut file-append <> "/share") packages)
":")))
(list
(shepherd-service
(documentation "LightDM display manager")
(requirement '(dbus-system user-processes host-name))
(provision '(lightdm display-manager xorg-server))
(respawn? #f)
(start
#~(lambda ()
;; Note: sadly, environment variables defined for 'lightdm' are
;; cleared and/or overridden by /etc/profile by its spawned greeters,
;; so an out-of-band means such as /etc is required.
(fork+exec-command #$lightdm-command
;; Lightdm needs itself in its PATH.
#:environment-variables
(list
;; It knows to look for greeter configurations in
;; XDG_CONFIG_DIRS...
(string-append "XDG_CONFIG_DIRS="
#$greeters-config-dir)
;; ... and for greeter .desktop files as well as
;; lightdm accountsservice interface in
;; XDG_DATA_DIRS.
(string-append "XDG_DATA_DIRS="
#$data-dirs)
(string-append "PATH=" #$lightdm-paths)))))
(stop #~(make-kill-destructor)))))
(define lightdm-service-type
(handle-xorg-configuration
lightdm-configuration
(service-type
(name 'lightdm)
(default-value (lightdm-configuration))
(extensions
(list (service-extension pam-root-service-type lightdm-pam-services)
(service-extension shepherd-root-service-type
lightdm-shepherd-service)
(service-extension activation-service-type
(const %lightdm-activation))
(service-extension dbus-root-service-type
(compose list lightdm-configuration-lightdm))
(service-extension polkit-service-type
(compose list lightdm-configuration-lightdm))
(service-extension account-service-type
(const %lightdm-accounts))
;; Add 'lightdm' to the system profile, so that its
;; 'share/accountsservice' D-Bus service extension directory can be
;; found via the 'XDG_DATA_DIRS=/run/current-system/profile/share'
;; environment variable set in the wrapper of the
;; libexec/accounts-daemon binary of the accountsservice package.
;; This daemon is spawned by D-Bus, and there's little we can do to
;; affect its environment. For more reading, see:
;; https://github.com/NixOS/nixpkgs/issues/45059.
(service-extension profile-service-type
lightdm-configuration->packages)
;; This is needed for the greeter itself to find its configuration,
;; because XDG_CONF_DIRS gets overridden by /etc/profile.
(service-extension
etc-service-type
(lambda (config)
`(("lightdm"
,(lightdm-configuration->greeters-config-dir config)))))))
(description "Run @code{lightdm}, the LightDM graphical login manager."))))
;;;
;;; Generate documentation.
;;;
(define (generate-doc)
(configuration->documentation 'lightdm-configuration)
(configuration->documentation 'lightdm-gtk-greeter-configuration)
(configuration->documentation 'lightdm-seat-configuration))

160
gnu/tests/lightdm.scm Normal file

@ -0,0 +1,160 @@
;;; GNU Guix --- Functional package management for GNU
;;; 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 tests lightdm)
#:use-module (gnu bootloader)
#:use-module (gnu bootloader grub)
#:use-module (gnu packages)
#:use-module (gnu packages ocr)
#:use-module (gnu packages ratpoison)
#:use-module (gnu packages vnc)
#:use-module (gnu packages xorg)
#:use-module (gnu services)
#:use-module (gnu services base)
#:use-module (gnu services dbus)
#:use-module (gnu services desktop)
#:use-module (gnu services networking)
#:use-module (gnu services lightdm)
#:use-module (gnu services ssh)
#:use-module (gnu services xorg)
#:use-module (gnu system)
#:use-module (gnu system file-systems)
#:use-module (gnu system shadow)
#:use-module (gnu system vm)
#:use-module (gnu tests)
#:use-module (guix gexp)
#:use-module (guix modules)
#:use-module (srfi srfi-1)
#:export (%test-lightdm))
(define minimal-desktop-services
(list polkit-wheel-service
(service upower-service-type)
(accountsservice-service)
(service polkit-service-type)
(elogind-service)
(dbus-service)
x11-socket-directory-service))
(define %lightdm-os
(operating-system
(inherit %simple-os)
(packages (cons* ocrad ratpoison xterm %base-packages))
(services
(cons* (service lightdm-service-type
(lightdm-configuration
(allow-empty-passwords? #t)
(debug? #t)
(xdmcp? #t)
(vnc-server? #t)
(vnc-server-command
(file-append tigervnc-server "/bin/Xvnc"
" -SecurityTypes None"))
(greeters (list (lightdm-gtk-greeter-configuration
(allow-debugging? #t))))
(seats (list (lightdm-seat-configuration
(name "*")
(user-session "ratpoison"))))))
;; For debugging.
(service dhcp-client-service-type)
(service openssh-service-type
(openssh-configuration
(permit-root-login #t)
(allow-empty-passwords? #t)))
(append minimal-desktop-services
(remove (lambda (service)
(eq? (service-kind service) guix-service-type))
%base-services))))))
(define (run-lightdm-test)
"Run tests in %LIGHTDM-OS."
(define os (marionette-operating-system
%lightdm-os
#:imported-modules (source-module-closure
'((gnu services herd)))))
(define vm (virtual-machine os))
(define test
(with-imported-modules (source-module-closure
'((gnu build marionette)))
#~(begin
(use-modules (gnu build marionette)
(srfi srfi-26)
(srfi srfi-64))
(let ((marionette (make-marionette (list #$vm))))
(test-runner-current (system-test-runner #$output))
(test-begin "lightdm")
(test-assert "service is running"
(marionette-eval
'(begin
(use-modules (gnu services herd))
(start-service 'lightdm))
marionette))
(test-assert "service can be stopped"
(marionette-eval
'(begin
(use-modules (gnu services herd))
(stop-service 'lightdm))
marionette))
(test-assert "service can be restarted"
(marionette-eval
'(begin
(use-modules (gnu services herd))
(restart-service 'lightdm))
marionette))
(test-assert "login screen is displayed"
;; GNU Ocrad fails to recognize the "Log In" button text, so use
;; Tesseract.
(wait-for-screen-text marionette
(cut string-contains <> "Log In")
#:ocr #$(file-append tesseract-ocr
"/bin/tesseract")))
(test-assert "can connect to TCP port 5900 on IPv4"
(wait-for-tcp-port 5900 marionette))
;; The VNC server fails to listen to IPv6 due to "Error binding to
;; address [::]:5900: Address already in use" (see:
;; https://github.com/canonical/lightdm/issues/266).
(test-expect-fail 1)
(test-assert "can connect to TCP port 5900 on IPv6"
(wait-for-tcp-port 5900 marionette
#:address
`(make-socket-address
AF_INET6
(inet-pton AF_INET6 "::1")
5900)))
(test-end)))))
(gexp->derivation "lightdm-test" test))
(define %test-lightdm
(system-test
(name "lightdm")
(description "Basic tests for the LightDM service.")
(value (run-lightdm-test))))

@ -0,0 +1,52 @@
;;; GNU Guix --- Functional package management for GNU
;;; 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 (tests services lightdm)
#:use-module (guix diagnostics)
#:use-module (gnu services lightdm)
#:use-module (srfi srfi-64))
;;; Tests for the (gnu services lightdm) module.
;;; Access some internals for whitebox testing.
(define validate-lightdm-configuration (@@ (gnu services lightdm)
validate-lightdm-configuration))
(test-begin "lightdm-service")
(test-equal "error on missing greeter"
'ok
(catch 'quit
(lambda ()
(validate-lightdm-configuration (lightdm-configuration (greeters '()))))
(lambda _
'ok)))
(test-equal "error when a greeter has multiple configurations"
'ok
(catch 'quit
(lambda ()
(lightdm-configuration
(greeters (list (lightdm-gtk-greeter-configuration
(theme-name "boring"))
(lightdm-gtk-greeter-configuration
(theme-name "blue"))))))
(lambda _
'ok)))
(test-end "lightdm-service")