From f383838a091835b86d4a6ff1c256498bcdecadad Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ludovic=20Court=C3=A8s?= Date: Fri, 27 May 2022 22:41:55 +0200 Subject: [PATCH] services: elogind: When started by dbus-daemon, wait for the Shepherd service. Fixes . Previously shepherd and dbus-daemon would race to start elogind. In some cases (for instance if one logs in quickly enough on the tty), dbus-daemon would "win" and start elogind before shepherd has had a chance to do it. Consequently, shepherd would fail to start elogind and mark it as stopped and disabled, in turn preventing services that depend on it such as 'xorg-server' from starting. * gnu/services/desktop.scm (elogind-dbus-service): Rewrite to refer to a wrapper that waits for the 'elogind' Shepherd service. --- gnu/services/desktop.scm | 58 +++++++++++++++++++++++++++++++++++++--- 1 file changed, 54 insertions(+), 4 deletions(-) diff --git a/gnu/services/desktop.scm b/gnu/services/desktop.scm index 24fd43a207..0499071436 100644 --- a/gnu/services/desktop.scm +++ b/gnu/services/desktop.scm @@ -1075,10 +1075,60 @@ (define-syntax-rule (ini-file config file clause ...) ("HybridSleepMode" (sleep-list elogind-hybrid-sleep-mode)))) (define (elogind-dbus-service config) - (list (wrapped-dbus-service (elogind-package config) - "libexec/elogind/elogind" - `(("ELOGIND_CONF_FILE" - ,(elogind-configuration-file config)))))) + "Return a @file{org.freedesktop.login1.service} file that tells D-Bus how to +\"start\" elogind. In practice though, our elogind is started when booting by +shepherd. Thus, the @code{Exec} line of this @file{.service} file does not +explain how to start elogind; instead, it spawns a wrapper that waits for the +@code{elogind} shepherd service. This avoids a race condition where both +@command{shepherd} and @command{dbus-daemon} would attempt to start elogind." + ;; For more info on the elogind startup race, see + ;; . + + (define elogind + (elogind-package config)) + + (define wrapper + (program-file "elogind-dbus-shepherd-sync" + (with-imported-modules '((gnu services herd)) + #~(begin + (use-modules (gnu services herd) + (srfi srfi-34)) + + (guard (c ((service-not-found-error? c) + (format (current-error-port) + "no elogind shepherd service~%") + (exit 1)) + ((shepherd-error? c) + (format (current-error-port) + "elogind shepherd service not \ +started~%") + (exit 2))) + (wait-for-service 'elogind)))))) + + (define build + (with-imported-modules '((guix build utils)) + #~(begin + (use-modules (guix build utils) + (ice-9 match)) + + (define service-directory + "/share/dbus-1/system-services") + + (mkdir-p (dirname (string-append #$output service-directory))) + (copy-recursively (string-append #$elogind service-directory) + (string-append #$output service-directory)) + (symlink (string-append #$elogind "/etc") ;for etc/dbus-1 + (string-append #$output "/etc")) + + ;; Replace the "Exec=" line of the 'org.freedesktop.login1.service' + ;; file with one that refers to WRAPPER instead of elogind. + (match (find-files #$output "\\.service$") + ((file) + (substitute* file + (("Exec[[:blank:]]*=.*" _) + (string-append "Exec=" #$wrapper "\n")))))))) + + (list (computed-file "elogind-dbus-service-wrapper" build))) (define (pam-extension-procedure config) "Return an extension for PAM-ROOT-SERVICE-TYPE that ensures that all the PAM