Add _add_event at the end of update_task

This patch adds call of _add_event method at the end of the update_task.
So now in event-list output user can see, that updating stack is
completed or failed.
Also status reason for update_task were changed to be inline with status
reason in the main stack_task method.

Method set_state is not used due to using stack.store method in the end
of update to avoid duplicate update.

Change-Id: Ic94c95f1558fd67f351696645426c00de8db1bf8
Closes-Bug: #1465321

heat/engine/stack.py

@@ -1152,12 +1152,8 @@ class Stack(collections.Mapping):
             finally:
                 self.reset_dependencies()
 
-            if action == self.UPDATE:
-                reason = 'Stack successfully updated'
-            elif action == self.RESTORE:
-                reason = 'Stack successfully restored'
-            else:
-                reason = 'Stack rollback completed'
+            if action in (self.UPDATE, self.RESTORE, self.ROLLBACK):
+                reason = 'Stack %s completed successfully' % action
             stack_status = self.COMPLETE
 
         except scheduler.Timeout:
@@ -1198,7 +1194,9 @@ class Stack(collections.Mapping):
         self.status_reason = reason
 
         notification.send(self)
+        self._add_event(self.action, self.status, self.status_reason)
         self.store()
+
         lifecycle_plugin_utils.do_post_ops(self.context, self,
                                            newstack, action,
                                            (self.status == self.FAILED))

heat/tests/test_engine_service.py

@@ -1522,7 +1522,7 @@ class StackServiceTest(common.HeatTestCase):
         self.assertTrue(result['stack_id'])
         events = self.eng.list_events(self.ctx, self.stack.identifier())
 
-        self.assertEqual(9, len(events))
+        self.assertEqual(10, len(events))
 
         for ev in events:
             self.assertIn('event_identity', ev)