nixpkgs-suyu/nixos/modules/services/x11/display-managers/default.nix
Tor Hedin Brønner 9fad9fb869
nixos/displayManager: Create a common environment wrapper for all dms
This makes it easier to support a wider variety of .desktop session files. In
particular this makes it possible to use both the «legacy» sessions and upstream
session files.

We separate `xsession` into two parts, `xsessionWrapper` and `xsession`.
`xsessionWrapper` sets up the correct environment and then lauches the session's
Exec command (from the .desktop file), falling back to launching the default
window/desktopManager through the `xsession` script (required by at least some
nixos tests).

`xsession` then _only_ handles launching desktop-managers/window-managers defined
through `services.xserver.desktopManager.session`.
2018-08-01 19:14:32 +02:00

355 lines
11 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
'';
# 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) ''
${optionalString (!config.hardware.pulseaudio.systemWide)
"${config.hardware.pulseaudio.package.out}/bin/pulseaudio --start"
}
# Publish access credentials in the root window.
${config.hardware.pulseaudio.package.out}/bin/pactl load-module module-x11-publish "display=$DISPLAY"
''}
# 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.
# FIXME: Check XDG_SESSION_TYPE against x11
${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
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
${concatMapStrings (s: ''
(${s.name})
${s.start}
;;
'') wm}
(*) echo "$0: Window manager '$windowManager' not found.";;
esac
# Start the desktop manager.
case "$desktopManager" in
${concatMapStrings (s: ''
(${s.name})
${s.start}
;;
'') 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: ''
${xorg.lndir}/bin/lndir ${pkg}/share/xsessions $out/share/xsessions
'') cfg.displayManager.extraSessionFilePackages}
'';
in
{
options = {
services.xserver.displayManager = {
xauthBin = mkOption {
internal = true;
default = "${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.";
};
sessionCommands = mkOption {
type = types.lines;
default = "";
example =
''
xmessage "Hello World!" &
'';
description = "Shell commands executed just before the window or desktop manager is started.";
};
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 windows 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.")
];
}