Log the error when a resouce fails to delete

Also bail out of handle_delete if instance_id is None

Change-Id: I2bd77345ac35860201006a23999a06dd81ac6fe0
Signed-off-by: Angus Salkeld <asalkeld@redhat.com>

heat/engine/instance.py

@@ -287,6 +287,8 @@ class Instance(resources.Resource):
         '''
         Delete an instance, blocking until it is disposed by OpenStack
         '''
+        if self.instance_id is None:
+            return
         try:
             server = self.nova().servers.get(self.instance_id)
         except NotFound:

heat/engine/parser.py

@@ -559,6 +559,8 @@ class Stack(object):
         for res in reversed(self):
             result = res.destroy()
             if result:
+                logger.error('Failed to delete %s error: %s' % (str(res),
+                                                                result))
                 failures.append(str(res))
 
         if failures:

heat/engine/user.py

@@ -60,6 +60,8 @@ class User(Resource):
         return self.UPDATE_REPLACE
 
     def handle_delete(self):
+        if self.instance_id is None:
+            return
         try:
             user = self.keystone().users.get(DummyId(self.instance_id))
         except Exception as ex: