nixpkgs/nixos/modules/services/x11/display-managers/default.nix
Hugo Geoffroy a23798e478 nixos/x11: provide selected session to custom session
The custom session script is always executed (when it exists). This change
passes the selected session script and select session name to the custom session
script, so that it can defer to the selected session script based on the value
of the selected session name.
2019-08-28 16:58:12 +02:00

377 lines
12 KiB
Nix

# This module declares the options to define a *display manager*, the
# program responsible for handling X logins (such as xdm, gdb, or
# SLiM). The display manager allows the user to select a *session
# type*. When the user logs in, the display manager starts the
# *session script* ("xsession" below) to launch the selected session
# type. The session type defines two things: the *desktop manager*
# (e.g., KDE, Gnome or a plain xterm), and optionally the *window
# manager* (e.g. kwin or twm).
{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.services.xserver;
xorg = pkgs.xorg;
fontconfig = config.fonts.fontconfig;
xresourcesXft = pkgs.writeText "Xresources-Xft" ''
${optionalString (fontconfig.dpi != 0) ''Xft.dpi: ${toString fontconfig.dpi}''}
Xft.antialias: ${if fontconfig.antialias then "1" else "0"}
Xft.rgba: ${fontconfig.subpixel.rgba}
Xft.lcdfilter: lcd${fontconfig.subpixel.lcdfilter}
Xft.hinting: ${if fontconfig.hinting.enable then "1" else "0"}
Xft.autohint: ${if fontconfig.hinting.autohint then "1" else "0"}
Xft.hintstyle: hintslight
'';
mkCases = session:
concatStrings (
mapAttrsToList (name: starts: ''
(${name})
${concatMapStringsSep "\n " (n: n.start) starts}
;;
'') (lib.groupBy (n: n.name) session)
);
# file provided by services.xserver.displayManager.session.wrapper
xsessionWrapper = pkgs.writeScript "xsession-wrapper"
''
#! ${pkgs.bash}/bin/bash
# Shared environment setup for graphical sessions.
. /etc/profile
cd "$HOME"
${optionalString cfg.startDbusSession ''
if test -z "$DBUS_SESSION_BUS_ADDRESS"; then
exec ${pkgs.dbus.dbus-launch} --exit-with-session "$0" "$@"
fi
''}
${optionalString cfg.displayManager.job.logToJournal ''
if [ -z "$_DID_SYSTEMD_CAT" ]; then
export _DID_SYSTEMD_CAT=1
exec ${config.systemd.package}/bin/systemd-cat -t xsession "$0" "$@"
fi
''}
${optionalString cfg.displayManager.job.logToFile ''
exec &> >(tee ~/.xsession-errors)
''}
# Start PulseAudio if enabled.
${optionalString (config.hardware.pulseaudio.enable) ''
# Publish access credentials in the root window.
if ${config.hardware.pulseaudio.package.out}/bin/pulseaudio --dump-modules | grep module-x11-publish &> /dev/null; then
${config.hardware.pulseaudio.package.out}/bin/pactl load-module module-x11-publish "display=$DISPLAY"
fi
''}
# Tell systemd about our $DISPLAY and $XAUTHORITY.
# This is needed by the ssh-agent unit.
#
# Also tell systemd about the dbus session bus address.
# This is required by user units using the session bus.
${config.systemd.package}/bin/systemctl --user import-environment DISPLAY XAUTHORITY DBUS_SESSION_BUS_ADDRESS
# Load X defaults. This should probably be safe on wayland too.
${xorg.xrdb}/bin/xrdb -merge ${xresourcesXft}
if test -e ~/.Xresources; then
${xorg.xrdb}/bin/xrdb -merge ~/.Xresources
elif test -e ~/.Xdefaults; then
${xorg.xrdb}/bin/xrdb -merge ~/.Xdefaults
fi
# Speed up application start by 50-150ms according to
# http://kdemonkey.blogspot.nl/2008/04/magic-trick.html
rm -rf "$HOME/.compose-cache"
mkdir "$HOME/.compose-cache"
# Work around KDE errors when a user first logs in and
# .local/share doesn't exist yet.
mkdir -p "$HOME/.local/share"
unset _DID_SYSTEMD_CAT
${cfg.displayManager.sessionCommands}
# Allow the user to execute commands at the beginning of the X session.
if test -f ~/.xprofile; then
source ~/.xprofile
fi
# Start systemd user services for graphical sessions
${config.systemd.package}/bin/systemctl --user start graphical-session.target
# Allow the user to setup a custom session type.
if test -x ~/.xsession; then
eval exec ~/.xsession "$@"
fi
if test "$1"; then
# Run the supplied session command. Remove any double quotes with eval.
eval exec "$@"
else
# Fall back to the default window/desktopManager
exec ${cfg.displayManager.session.script}
fi
'';
# file provided by services.xserver.displayManager.session.script
xsession = wm: dm: pkgs.writeScript "xsession"
''
#! ${pkgs.bash}/bin/bash
# Legacy session script used to construct .desktop files from
# `services.xserver.displayManager.session` entries. Called from
# `sessionWrapper`.
# Expected parameters:
# $1 = <desktop-manager>+<window-manager>
# The first argument of this script is the session type.
sessionType="$1"
if [ "$sessionType" = default ]; then sessionType=""; fi
# The session type is "<desktop-manager>+<window-manager>", so
# extract those (see:
# http://wiki.bash-hackers.org/syntax/pe#substring_removal).
windowManager="''${sessionType##*+}"
: ''${windowManager:=${cfg.windowManager.default}}
desktopManager="''${sessionType%%+*}"
: ''${desktopManager:=${cfg.desktopManager.default}}
# Start the window manager.
case "$windowManager" in
${mkCases wm}
(*) echo "$0: Window manager '$windowManager' not found.";;
esac
# Start the desktop manager.
case "$desktopManager" in
${mkCases dm}
(*) echo "$0: Desktop manager '$desktopManager' not found.";;
esac
${optionalString cfg.updateDbusEnvironment ''
${lib.getBin pkgs.dbus}/bin/dbus-update-activation-environment --systemd --all
''}
test -n "$waitPID" && wait "$waitPID"
${config.systemd.package}/bin/systemctl --user stop graphical-session.target
exit 0
'';
# Desktop Entry Specification:
# - https://standards.freedesktop.org/desktop-entry-spec/latest/
# - https://standards.freedesktop.org/desktop-entry-spec/latest/ar01s06.html
mkDesktops = names: pkgs.runCommand "desktops"
{ # trivial derivation
preferLocalBuild = true;
allowSubstitutes = false;
}
''
mkdir -p "$out/share/xsessions"
${concatMapStrings (n: ''
cat - > "$out/share/xsessions/${n}.desktop" << EODESKTOP
[Desktop Entry]
Version=1.0
Type=XSession
TryExec=${cfg.displayManager.session.script}
Exec=${cfg.displayManager.session.script} "${n}"
Name=${n}
Comment=
EODESKTOP
'') names}
${concatMapStrings (pkg: ''
if test -d ${pkg}/share/xsessions; then
${xorg.lndir}/bin/lndir ${pkg}/share/xsessions $out/share/xsessions
fi
'') cfg.displayManager.extraSessionFilePackages}
${concatMapStrings (pkg: ''
if test -d ${pkg}/share/wayland-sessions; then
mkdir -p "$out/share/wayland-sessions"
${xorg.lndir}/bin/lndir ${pkg}/share/wayland-sessions $out/share/wayland-sessions
fi
'') cfg.displayManager.extraSessionFilePackages}
'';
in
{
options = {
services.xserver.displayManager = {
xauthBin = mkOption {
internal = true;
default = "${xorg.xauth}/bin/xauth";
description = "Path to the <command>xauth</command> program used by display managers.";
};
xserverBin = mkOption {
type = types.path;
description = "Path to the X server used by display managers.";
};
xserverArgs = mkOption {
type = types.listOf types.str;
default = [];
example = [ "-ac" "-logverbose" "-verbose" "-nolisten tcp" ];
description = "List of arguments for the X server.";
};
setupCommands = mkOption {
type = types.lines;
default = "";
description = ''
Shell commands executed just after the X server has started.
This option is only effective for display managers for which this feature
is supported; currently these are LightDM, GDM and SDDM.
'';
};
sessionCommands = mkOption {
type = types.lines;
default = "";
example =
''
xmessage "Hello World!" &
'';
description = ''
Shell commands executed just before the window or desktop manager is
started. These commands are not currently sourced for Wayland sessions.
'';
};
hiddenUsers = mkOption {
type = types.listOf types.str;
default = [ "nobody" ];
description = ''
A list of users which will not be shown in the display manager.
'';
};
extraSessionFilePackages = mkOption {
type = types.listOf types.package;
default = [];
description = ''
A list of packages containing xsession files to be passed to the display manager.
'';
};
session = mkOption {
default = [];
example = literalExample
''
[ { manage = "desktop";
name = "xterm";
start = '''
''${pkgs.xterm}/bin/xterm -ls &
waitPID=$!
''';
}
]
'';
description = ''
List of sessions supported with the command used to start each
session. Each session script can set the
<varname>waitPID</varname> shell variable to make this script
wait until the end of the user session. Each script is used
to define either a window manager or a desktop manager. These
can be differentiated by setting the attribute
<varname>manage</varname> either to <literal>"window"</literal>
or <literal>"desktop"</literal>.
The list of desktop manager and window manager should appear
inside the display manager with the desktop manager name
followed by the window manager name.
'';
apply = list: rec {
wm = filter (s: s.manage == "window") list;
dm = filter (s: s.manage == "desktop") list;
names = flip concatMap dm
(d: map (w: d.name + optionalString (w.name != "none") ("+" + w.name))
(filter (w: d.name != "none" || w.name != "none") wm));
desktops = mkDesktops names;
script = xsession wm dm;
wrapper = xsessionWrapper;
};
};
job = {
preStart = mkOption {
type = types.lines;
default = "";
example = "rm -f /var/log/my-display-manager.log";
description = "Script executed before the display manager is started.";
};
execCmd = mkOption {
type = types.str;
example = literalExample ''
"''${pkgs.slim}/bin/slim"
'';
description = "Command to start the display manager.";
};
environment = mkOption {
type = types.attrsOf types.unspecified;
default = {};
example = { SLIM_CFGFILE = "/etc/slim.conf"; };
description = "Additional environment variables needed by the display manager.";
};
logToFile = mkOption {
type = types.bool;
default = false;
description = ''
Whether the display manager redirects the output of the
session script to <filename>~/.xsession-errors</filename>.
'';
};
logToJournal = mkOption {
type = types.bool;
default = true;
description = ''
Whether the display manager redirects the output of the
session script to the systemd journal.
'';
};
};
};
};
config = {
services.xserver.displayManager.xserverBin = "${xorg.xorgserver.out}/bin/X";
systemd.user.targets.graphical-session = {
unitConfig = {
RefuseManualStart = false;
StopWhenUnneeded = false;
};
};
};
imports = [
(mkRemovedOptionModule [ "services" "xserver" "displayManager" "desktopManagerHandlesLidAndPower" ]
"The option is no longer necessary because all display managers have already delegated lid management to systemd.")
];
}