diff options
| -rw-r--r-- | doc/guix.texi | 34 | ||||
| -rw-r--r-- | gnu/home/services/desktop.scm | 109 |
2 files changed, 135 insertions, 8 deletions
diff --git a/doc/guix.texi b/doc/guix.texi index b90078be06..9f06f1c325 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -44475,6 +44475,40 @@ The @code{(gnu home services desktop)} module provides services that you may find useful on ``desktop'' systems running a graphical user environment such as Xorg. +@cindex X Window, for Guix Home services +@cindex X11, in Guix Home +@defvar home-x11-service-type +This is the service type representing the X Window graphical display +server (also referred to as ``X11''). + +X Window is necessarily started by a system service; on Guix System, +starting it is the responsibility of @code{gdm-service-type} and similar +services (@pxref{X Window}). At the level of Guix Home, as an +unprivileged user, we cannot start X Window; all we can do is check +whether it is running. This is what this service does. + +As a user, you probably don't need to worry or explicitly instantiate +@code{home-x11-service-type}. Services that require an X Window +graphical display, such as @code{home-redshift-service-type} below, +instantiate it and depend on its corresponding @code{x11-display} +Shepherd service (@pxref{Shepherd Home Service}). + +When X Window is running, the @code{x11-display} Shepherd service starts +and sets the @env{DISPLAY} environment variable of the +@command{shepherd} process, using its original value if it was already +set; otherwise, it fails to start. + +The service can also be forced to use a given value for @env{DISPLAY}, +like so: + +@example +herd start x11-display :3 +@end example + +In the example above, @code{x11-display} is instructed to set +@env{DISPLAY} to @code{:3}. +@end defvar + @defvar home-redshift-service-type This is the service type for @uref{https://github.com/jonls/redshift, Redshift}, a program that adjusts the display color temperature diff --git a/gnu/home/services/desktop.scm b/gnu/home/services/desktop.scm index c4da116100..91465bf168 100644 --- a/gnu/home/services/desktop.scm +++ b/gnu/home/services/desktop.scm @@ -1,5 +1,5 @@ ;;; GNU Guix --- Functional package management for GNU -;;; Copyright © 2022 Ludovic Courtès <ludo@gnu.org> +;;; Copyright © 2022-2023 Ludovic Courtès <ludo@gnu.org> ;;; Copyright © 2022 ( <paren@disroot.org> ;;; Copyright © 2023 conses <contact@conses.eu> ;;; Copyright © 2023 Janneke Nieuwenhuizen <janneke@gnu.org> @@ -30,7 +30,9 @@ #:use-module (guix gexp) #:use-module (srfi srfi-1) #:use-module (ice-9 match) - #:export (home-redshift-configuration + #:export (home-x11-service-type + + home-redshift-configuration home-redshift-configuration? home-redshift-service-type @@ -45,6 +47,79 @@ ;;; +;;; Waiting for X11. +;;; + +(define (x11-shepherd-service delay) + (list (shepherd-service + (provision '(x11-display)) + (modules '((ice-9 ftw) + (ice-9 match) + (srfi srfi-1))) + (start + #~(lambda* (#:optional (display (getenv "DISPLAY"))) + (define x11-directory + "/tmp/.X11-unix") + + (define (find-display delay) + ;; Wait for an accessible socket to show up in X11-DIRECTORY, + ;; up to DELAY seconds. + (let loop ((attempts delay)) + (define socket + (find (match-lambda + ((or "." "..") #f) + (name + (let ((name (in-vicinity x11-directory + name))) + (access? name O_RDWR)))) + (or (scandir x11-directory) '()))) + + (if (and socket (string-prefix? "X" socket)) + (let ((display (string-append + ":" (string-drop socket 1)))) + (format #t "X11 display server found at ~s.~%" + display) + display) + (if (zero? attempts) + (begin + (format (current-error-port) + "X11 display server did not show up; \ +giving up.\n") + #f) + (begin + (sleep 1) + (loop (- attempts 1))))))) + + (let ((display (or display (find-display #$delay)))) + (when display + ;; Note: 'make-forkexec-constructor' calls take their + ;; default #:environment-variables value before this service + ;; is started and are thus unaffected by the 'setenv' call + ;; below. Users of this service have to explicitly query + ;; its value. + (setenv "DISPLAY" display)) + display))) + (stop #~(lambda (_) + (unsetenv "DISPLAY") + #f)) + (respawn? #f)))) + +(define home-x11-service-type + (service-type + (name 'home-x11-display) + (extensions (list (service-extension home-shepherd-service-type + x11-shepherd-service))) + (default-value 10) + (description + "Create a @code{x11-display} Shepherd service that waits for the X +Window (or ``X11'') graphical display server to be up and running, up to a +configurable delay, and sets the @code{DISPLAY} environment variable of +@command{shepherd} itself accordingly. If no accessible X11 server shows up +during that time, the @code{x11-display} service is marked as failing to +start."))) + + +;;; ;;; Redshift. ;;; @@ -169,11 +244,25 @@ format.")) (list (shepherd-service (documentation "Redshift program.") (provision '(redshift)) - ;; FIXME: This fails to start if Home is first activated from a - ;; non-X11 session. - (start #~(make-forkexec-constructor - (list #$(file-append (home-redshift-configuration-redshift config) "/bin/redshift") - "-c" #$config-file))) + + ;; Depend on 'x11-display', which sets 'DISPLAY' if an X11 server is + ;; available, and fails to start otherwise. + (requirement '(x11-display)) + + (modules '((srfi srfi-1) + (srfi srfi-26))) + (start #~(lambda _ + (fork+exec-command + (list #$(file-append + (home-redshift-configuration-redshift config) + "/bin/redshift") + "-c" #$config-file) + + ;; Inherit the 'DISPLAY' variable set by 'x11-display'. + #:environment-variables + (cons (string-append "DISPLAY=" (getenv "DISPLAY")) + (remove (cut string-prefix? "DISPLAY=" <>) + (default-environment-variables)))))) (stop #~(make-kill-destructor)) (actions (list (shepherd-configuration-action config-file)))))) @@ -181,7 +270,11 @@ format.")) (service-type (name 'home-redshift) (extensions (list (service-extension home-shepherd-service-type - redshift-shepherd-service))) + redshift-shepherd-service) + ;; Ensure 'home-x11-service-type' is instantiated so we + ;; can depend on the Shepherd 'x11-display' service. + (service-extension home-x11-service-type + (const #t)))) (default-value (home-redshift-configuration)) (description "Run Redshift, a program that adjusts the color temperature of display |