nixpkgs/nixos/modules/services/x11/display-managers/set-session.py
worldofpeace d8b50bfe47 nixos/gdm: make desktopManager.default work
Unfortunately, you can't configure the default user-session
with GDM like lightdm. I've opened a feature request [0]
but I'd like to be able to do this now.

We use a GObject Python script using bindings to AccountsService
to achieve this. I'm hoping the reliable heuristic for session names
is the file's basename. We also have some special logic for which
method to use to set the default session. It seems set_x_session is
deprecated, and thusly the XSession key, but if that method isn't used
when it's an xsession it won't be the default in GDM.

[0]: https://gitlab.gnome.org/GNOME/gdm/issues/535
2019-11-22 17:47:03 -05:00

86 lines
2.5 KiB
Python
Executable File

#!/usr/bin/env python
import gi, argparse, os, logging, sys
gi.require_version("AccountsService", "1.0")
from gi.repository import AccountsService, GLib
from ordered_set import OrderedSet
def get_session_file(session):
system_data_dirs = GLib.get_system_data_dirs()
session_dirs = OrderedSet(
os.path.join(data_dir, session)
for data_dir in system_data_dirs
for session in {"wayland-sessions", "xsessions"}
)
session_files = OrderedSet(
os.path.join(dir, session + ".desktop")
for dir in session_dirs
if os.path.exists(os.path.join(dir, session + ".desktop"))
)
# Deal with duplicate wayland-sessions and xsessions.
# Needed for the situation in gnome-session, where there's
# a xsession named the same as a wayland session.
if any(map(is_session_wayland, session_files)):
session_files = OrderedSet(
session for session in session_files if is_session_wayland(session)
)
else:
session_files = OrderedSet(
session for session in session_files if is_session_xsession(session)
)
if len(session_files) == 0:
logging.warning("No session files are found.")
sys.exit(0)
else:
return session_files[0]
def is_session_xsession(session_file):
return "/xsessions/" in session_file
def is_session_wayland(session_file):
return "/wayland-sessions/" in session_file
def main():
parser = argparse.ArgumentParser(
description="Set session type for all normal users."
)
parser.add_argument("session", help="Name of session to set.")
args = parser.parse_args()
session = getattr(args, "session")
session_file = get_session_file(session)
user_manager = AccountsService.UserManager.get_default()
users = user_manager.list_users()
for user in users:
if user.is_system_account():
continue
else:
if is_session_wayland(session_file):
logging.debug(
f"Setting session name: {session}, as we found the existing wayland-session: {session_file}"
)
user.set_session(session)
elif is_session_xsession(session_file):
logging.debug(
f"Setting session name: {session}, as we found the existing xsession: {session_file}"
)
user.set_x_session(session)
else:
raise Exception(f"Couldn't figure out session type for {session_file}")
if __name__ == "__main__":
main()