gendsession

Automatically trigger execution of a script during user logout on Gnome based systems using Gnome Session Manager's EndSession DBus interface.

Description

Triggering a script for execution at login on Gnome based systems is a trivial task, just add the script in the Startup Applications dialog and everthing is taken automatically care of.

Triggering a script for execution at logout on Gnome based systems is on the contrary not at all trivial. This script aims to remedy that by taking care of the messy details of the Gnome Session Manager's EndSession DBus signalling.

Example Use-Case

Automatically unmounting of user-specific encrypted filesystems when the user logs out. This applies to other mounts than /home/$USER as there are already existing tools for auto-mounting private home directories in most distros.

Usage

$ ./gendsession.py <path-to-logout-actions-script> [logout-actions-script-args]

Typical Usage: Run both login and logout actions

Create a script that performs the login actions, e.g. login-actions.sh
Create a script that performs the logout actions, e.g. logout-actions.sh
Create a wrapper script that is added to the Startup Applications dialog

#!/bin/sh

# Assume that all scripts are located in the same directory as this script
path=$(dirname $(readlink -f $0))

# These actions will be executed during login
$path/login-actions.sh

# This starts a listener for logout signalling and executes the actions during logout
$path/gendsession.py $path/logout-actions.sh

Other Usage: Subclassing

It is also possible to subclass the functionality from within Python scripts if this is desired

#!/usr/bin/python

import gendsession

class MySubClassExample(gendsession.GEndSessionListenerBase):
    def end_session_actions(self):
        print "Performing user specified logout actions"

example = MySubClassExample()
example.start()

Supported Platforms

All Gnome based systems should be supported. Verified on:

v1.0: Ubuntu 14.10 through to 17.04
v1.1: Ubuntu 19.10 through to 20.04

Background

To trigger a script for execution during a logout on Gnome based systems one can register for the Gnome Session Manager's DBus EndSession signals. The main problem is that the Gnome Session Manager DBus interface is largely under-documented and therefore not trivial to understand how to use.

jeffshee/gendsession