Merge lp:~blake-rouse/maas/fix-1677936 into lp:~maas-committers/maas/trunk

[Blake Rouse]

Handle an event no longer existing in listen handler for EventHandler.

[Lee Trager (ltrager)]

LGTM!

review: Approve

=== modified file 'src/maasserver/websockets/handlers/event.py'
--- src/maasserver/websockets/handlers/event.py	2016-06-22 17:03:02 +0000
+++ src/maasserver/websockets/handlers/event.py	2017-04-10 20:10:45 +0000
@@ -109,7 +109,10 @@
         # Only care about create everything else is ignored.
         if action != "create":
             return None
-        obj = self.listen(channel, action, pk)
+        try:
+            obj = self.listen(channel, action, pk)
+        except HandlerDoesNotExistError:
+            return None
         if obj is None:
             return None
         if obj.node_id not in self.cache["node_ids"]:

=== modified file 'src/maasserver/websockets/handlers/tests/test_event.py'
--- src/maasserver/websockets/handlers/tests/test_event.py	2016-09-06 17:02:03 +0000
+++ src/maasserver/websockets/handlers/tests/test_event.py	2017-04-10 20:10:45 +0000
@@ -224,6 +224,15 @@
             handler.on_listen(sentinel.channel, action, pk)
             self.assertThat(mock_listen, MockNotCalled())
 
+    def test_on_listen_returns_None_if_obj_no_longer_exists(self):
+        user = factory.make_User()
+        handler = EventHandler(user, {})
+        mock_listen = self.patch(handler, "listen")
+        mock_listen.return_value = HandlerDoesNotExistError()
+        self.assertIsNone(
+            handler.on_listen(
+                sentinel.channel, sentinel.action, random.randint(1, 1000)))
+
     def test_on_listen_returns_None_if_listen_returns_None(self):
         user = factory.make_User()
         handler = EventHandler(user, {})