Create an event when signalling fails

- otherwise it is hard to know that signalling happened and failed
- remove the LOG.exception() - doesn't seem like a programming error.
- don't change the resource action/state
- this makes a functional test much more reliable

Change-Id: I84c73b06bade4dfcadba240eb3dddac698194acf
Partial-bug: #1334333

heat/engine/resource.py

@@ -1108,8 +1108,8 @@ class Resource(object):
         handler is implemented.
         '''
         if self.action in (self.SUSPEND, self.DELETE):
-            LOG.exception(_LE('Cannot signal resource '
-                              'during %s'), self.action)
+            self._add_event(self.action, self.status,
+                            'Cannot signal resource during %s' % self.action)
             ex = Exception(_('Cannot signal resource during %s') % self.action)
             raise exception.ResourceFailure(ex, self)
 

heat/tests/test_resource.py

@@ -131,10 +131,14 @@ class ResourceTest(common.HeatTestCase):
         for action in actions:
             for status in res.STATUSES:
                 res.state_set(action, status)
+                ev = self.patchobject(res, '_add_event')
                 ex = self.assertRaises(exception.ResourceFailure,
                                        res.signal)
                 self.assertEqual('Exception: Cannot signal resource during '
                                  '%s' % action, six.text_type(ex))
+                ev.assert_called_with(
+                    action, status,
+                    'Cannot signal resource during %s' % action)
 
     def test_resource_str_repr_stack_id_resource_id(self):
         tmpl = rsrc_defn.ResourceDefinition('test_res_str_repr', 'Foo')

heat_integrationtests/functional/test_autoscaling.py

@@ -742,6 +742,12 @@ outputs:
 
         # Send a signal and confirm nothing happened.
         self.client.resources.signal(stack_identifier, 'ScaleUpPolicy')
+        ev = self.wait_for_event_with_reason(
+            stack_identifier,
+            reason='Cannot signal resource during SUSPEND',
+            rsrc_name='ScaleUpPolicy')
+        self.assertEqual('SUSPEND_COMPLETE', ev[0].resource_status)
+
         # still SUSPEND_COMPLETE (not gone to UPDATE_COMPLETE)
         self._wait_for_stack_status(nested_ident, 'SUSPEND_COMPLETE')
         # still 2 instances.