heat engine : implement metadata_update per-resource

Abstract updates to resource metadata so they are implemented per-resource,
with a generic implementation which is a no-op, since currently the only
resource which needs metadata update via the RPC API is WaitConditionHandle.
This allows resource-specific metadata validation and update logic to be more
easily added.

ref bug 1097813

Change-Id: I094e74b6cd8cb2436f05beed9629fc3c3a34e622
Signed-off-by: Steven Hardy <shardy@redhat.com>

heat/engine/resource.py

@@ -429,6 +429,13 @@ def handle_update(self):
         raise NotImplementedError("Update not implemented for Resource %s"
                                   % type(self))
 
+    def metadata_update(self, metadata):
+        '''
+        No-op for resources which don't explicitly override this method
+        '''
+        logger.warning("Resource %s does not implement metadata update" %
+                       self.name)
+
 
 class GenericResource(Resource):
     properties_schema = {}

heat/engine/resources/wait_condition.py

@@ -113,6 +113,12 @@ def FnGetRefId(self):
         else:
             return unicode(self.name)
 
+    def metadata_update(self, metadata):
+        '''
+        Update the resource metadata
+        '''
+        self.metadata = metadata
+
 
 WAIT_STATUSES = (
     WAITING,

heat/engine/service.py

@@ -439,7 +439,7 @@ def metadata_update(self, context, stack_identity,
             raise AttributeError("Resource not found %s" % resource_name)
 
         resource = stack[resource_name]
-        resource.metadata = metadata
+        resource.metadata_update(metadata)
 
         return resource.metadata
 

heat/tests/test_engine_service.py

@@ -660,10 +660,13 @@ def test_stack_resources_list_nonexist_stack(self):
 
     def test_metadata(self):
         test_metadata = {'foo': 'bar', 'baz': 'quux', 'blarg': 'wibble'}
+        pre_update_meta = self.stack['WebServer'].metadata
         result = self.man.metadata_update(self.ctx,
                                           dict(self.stack_identity),
                                           'WebServer', test_metadata)
-        self.assertEqual(result, test_metadata)
+        # metadata_update is a no-op for all resources except
+        # WaitConditionHandle so we don't expect this to have changed
+        self.assertEqual(result, pre_update_meta)
 
     def test_metadata_err_stack(self):
         test_metadata = {'foo': 'bar', 'baz': 'quux', 'blarg': 'wibble'}

heat/tests/test_waitcondition.py

@@ -178,10 +178,6 @@ def create_stack(self, stack_name='test_stack2', params={}):
         uuid.uuid4().AndReturn('STACKABCD1234')
         self.m.ReplayAll()
         stack.store()
-        return stack
-
-    def test_handle(self):
-        stack = self.create_stack()
 
         # Stub waitcondition status so all goes CREATE_COMPLETE
         self.m.StubOutWithMock(wc.WaitCondition, '_get_status_reason')
@@ -199,6 +195,11 @@ def test_handle(self):
         self.m.StubOutWithMock(wc.WaitConditionHandle, 'identifier')
         wc.WaitConditionHandle.identifier().MultipleTimes().AndReturn(id)
 
+        return stack
+
+    def test_handle(self):
+        stack = self.create_stack()
+
         # Stub time to a fixed value so we can get an expected signature
         t = time.gmtime(1354196977)
         self.m.StubOutWithMock(time, 'gmtime')
@@ -229,3 +230,19 @@ def test_handle(self):
         stack.delete()
 
         self.m.VerifyAll()
+
+    def test_metadata_update(self):
+        stack = self.create_stack()
+        self.m.ReplayAll()
+        stack.create()
+
+        resource = stack.resources['WaitHandle']
+        self.assertEqual(resource.state, 'CREATE_COMPLETE')
+
+        test_metadata = {'foo': 'bar', 'baz': 'quux', 'blarg': 'wibble'}
+        resource.metadata_update(test_metadata)
+        self.assertEqual(resource.metadata, test_metadata)
+
+        stack.delete()
+
+        self.m.VerifyAll()