dbus-python-client.py

#!/usr/bin/env python3

import dbus
import dbus.mainloop.glib
from dbus.mainloop.glib import DBusGMainLoop
from gi.repository import GLib

dbus.mainloop.glib.DBusGMainLoop(set_as_default=True)

bus = dbus.SystemBus()

proxy = bus.get_object('org.freedesktop.systemd1', '/org/freedesktop/systemd1')

interface = dbus.Interface(proxy, 'org.freedesktop.systemd1.Manager')

interface.Subscribe()


def on_properties_changed(*args, **kargs):
    print('Status Changed....')
    if args:
        try:
            print(args[1][dbus.String("ActiveState")])
            print(args[1][dbus.String("SubState")])
            print(args[1][dbus.String("ExecMainStatus")])
        except KeyError:
            pass


properties_proxy = bus.get_object(
    'org.freedesktop.systemd1', interface.GetUnit('tester-unit.service')
)

properties_interface = dbus.Interface(
    properties_proxy, 'org.freedesktop.DBus.Properties'
)

properties_interface.connect_to_signal(
    'PropertiesChanged', on_properties_changed
)


DBusGMainLoop(set_as_default=True)
loop = GLib.MainLoop()
loop.run()