nixpkgs/nixos/modules/services/x11/display-managers/default.nix
Michael Weiss 1273f414a7 display-managers: Fix the xsession parameters
The xsession script was called with inconsistent (depending on the
display managers) and wrong parameters. The main reason for this where
the spaces the parameter syntax. In order to fix this the old syntax:
$1 = '<desktop-manager> + <window-manager>'
Will be replaced with a new syntax:
$1 = "<desktop-manager>+<window-manager>"

This assumes that neither "<desktop-manager>" nor "<window-manager>"
contain the "+" character but this shouldn't be a problem.

This patch also fixes the quoting by using double quotes (") instead of
single quotes (') [0].

Last but not least this'll add some comments for the better
understanding of the script.

[0]: https://specifications.freedesktop.org/desktop-entry-spec/latest/ar01s06.html
2017-04-28 22:00:14 +02:00

336 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.script
xsession = wm: dm: pkgs.writeScript "xsession"
''
#! ${pkgs.bash}/bin/bash
# Expected parameters:
# $1 = <desktop-manager>+<window-manager>
# Actual parameters (FIXME):
# SDDM is calling this script like the following:
# $1 = /nix/store/xxx-xsession (= $0)
# $2 = <desktop-manager>+<window-manager>
# SLiM is using the following parameter:
# $1 = /nix/store/xxx-xsession <desktop-manager>+<window-manager>
# LightDM keeps the double quotes:
# $1 = /nix/store/xxx-xsession "<desktop-manager>+<window-manager>"
# The fake/auto display manager doesn't use any parameters and GDM is
# broken.
# If you want to "debug" this script don't print the parameters to stdout
# or stderr because this script will be executed multiple times and the
# output won't be visible in the log when the script is executed for the
# first time (e.g. append them to a file instead)!
# All of the above cases are handled by the following hack (FIXME).
# Since this line is *very important* for *all display managers* it is
# very important to test changes to the following line with all display
# managers:
if [ "''${1:0:1}" = "/" ]; then eval exec "$1" "$2" ; fi
# Now it should be safe to assume that the script was called with the
# expected parameters.
${optionalString cfg.displayManager.logToJournal ''
if [ -z "$_DID_SYSTEMD_CAT" ]; then
_DID_SYSTEMD_CAT=1 exec ${config.systemd.package}/bin/systemd-cat -t xsession -- "$0" "$@"
fi
''}
. /etc/profile
cd "$HOME"
# The first argument of this script is the session type.
sessionType="$1"
if [ "$sessionType" = default ]; then sessionType=""; fi
${optionalString (!cfg.displayManager.job.logsXsession && !cfg.displayManager.logToJournal) ''
exec > ~/.xsession-errors 2>&1
''}
${optionalString cfg.startDbusSession ''
if test -z "$DBUS_SESSION_BUS_ADDRESS"; then
exec ${pkgs.dbus.dbus-launch} --exit-with-session "$0" "$sessionType"
fi
''}
# 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. This is needed by the
# ssh-agent unit.
${config.systemd.package}/bin/systemctl --user import-environment DISPLAY
# Load X defaults.
${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
${cfg.displayManager.sessionCommands}
# Allow the user to execute commands at the beginning of the X session.
if test -f ~/.xprofile; then
source ~/.xprofile
fi
# Allow the user to setup a custom session type.
if test -x ~/.xsession; then
exec ~/.xsession
else
if test "$sessionType" = "custom"; then
sessionType="" # fall-thru if there is no ~/.xsession
fi
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 "$waitPID"
exit 0
'';
# Desktop Entry Specification:
# - https://standards.freedesktop.org/desktop-entry-spec/latest/
# - https://standards.freedesktop.org/desktop-entry-spec/latest/ar01s06.html
mkDesktops = names: pkgs.runCommand "desktops"
{ # trivial derivation
preferLocalBuild = true;
allowSubstitutes = false;
}
''
mkdir -p "$out"
${concatMapStrings (n: ''
cat - > "$out/${n}.desktop" << EODESKTOP
[Desktop Entry]
Version=1.0
Type=XSession
TryExec=${cfg.displayManager.session.script}
Exec=${cfg.displayManager.session.script} "${n}"
X-GDM-BypassXsession=true
Name=${n}
Comment=
EODESKTOP
'') names}
'';
in
{
options = {
services.xserver.displayManager = {
xauthBin = mkOption {
internal = true;
default = "${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.
'';
};
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;
};
};
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 ''
"''${pkgs.slim}/bin/slim"
'';
description = "Command to start the display manager.";
};
environment = mkOption {
type = types.attrsOf types.unspecified;
default = {};
example = { SLIM_CFGFILE = "/etc/slim.conf"; };
description = "Additional environment variables needed by the display manager.";
};
logsXsession = mkOption {
type = types.bool;
default = false;
description = ''
Whether the display manager redirects the
output of the session script to
<filename>~/.xsession-errors</filename>.
'';
};
};
logToJournal = mkOption {
type = types.bool;
default = true;
description = ''
By default, the stdout/stderr of sessions is written
to <filename>~/.xsession-errors</filename>. When this option
is enabled, it will instead be written to the journal.
'';
};
};
};
config = {
services.xserver.displayManager.xserverBin = "${xorg.xorgserver.out}/bin/X";
};
imports = [
(mkRemovedOptionModule [ "services" "xserver" "displayManager" "desktopManagerHandlesLidAndPower" ]
"The option is no longer necessary because all display managers have already delegated lid management to systemd.")
];
}