zabbix/accounting: Discover .slice units

Signed-off-by: Florian Pritz <bluewind@xinu.at>

roles/zabbix-agent/files/systemd-discover-accounting-units.py

@@ -11,15 +11,23 @@ units = systemd1_manager.ListUnits()
 
 discovered = []
 
-def get_unit_prop(interface, propname):
+def get_unit_prop_interface(obj, interface, propname):
     try:
-        return unit_properties.Get('org.freedesktop.systemd1.Service', propname)
+        return obj.Get(interface, propname)
     except dbus.exceptions.DBusException as err:
         if err.get_dbus_name() == 'org.freedesktop.DBus.Error.UnknownProperty':
             return None
         else:
             raise
 
+def get_unit_prop(obj, propname):
+    interfaces = ['org.freedesktop.systemd1.Service', 'org.freedesktop.systemd1.Slice']
+    for interface in interfaces:
+        ret = get_unit_prop_interface(obj, interface, propname)
+        if ret:
+            return ret
+    return None
+
 for u in units:
     unit_properties = dbus.Interface(bus.get_object('org.freedesktop.systemd1', u[6]), dbus_interface='org.freedesktop.DBus.Properties')
     if get_unit_prop(unit_properties, "CPUAccounting") or get_unit_prop(unit_properties, "MemoryAccounting"):