Implement execute change set endpoint (#1391)

IMPLEMENTATION_COVERAGE.md

@@ -329,7 +329,7 @@
 - [ ] update_schema
 - [ ] update_typed_link_facet
 
-## cloudformation - 20% implemented
+## cloudformation - 23% implemented
 - [ ] cancel_update_stack
 - [ ] continue_update_rollback
 - [X] create_change_set
@@ -350,7 +350,7 @@
 - [ ] describe_stack_set_operation
 - [X] describe_stacks
 - [ ] estimate_template_cost
-- [ ] execute_change_set
+- [X] execute_change_set
 - [ ] get_stack_policy
 - [ ] get_template
 - [ ] get_template_summary

moto/cloudformation/models.py

@@ -188,6 +188,24 @@ class CloudFormationBackend(BaseBackend):
         self.change_sets[change_set_id] = stack
         return change_set_id, stack.stack_id
 
+    def execute_change_set(self, change_set_name, stack_name=None):
+        stack = None
+        if change_set_name in self.change_sets:
+            # This means arn was passed in
+            stack = self.change_sets[change_set_name]
+        else:
+            for cs in self.change_sets:
+                if self.change_sets[cs].name == change_set_name:
+                    stack = self.change_sets[cs]
+        if stack is None:
+            raise ValidationError(stack_name)
+        if stack.events[-1].resource_status == 'REVIEW_IN_PROGRESS':
+            stack._add_stack_event('CREATE_COMPLETE')
+        else:
+            stack._add_stack_event('UPDATE_IN_PROGRESS')
+            stack._add_stack_event('UPDATE_COMPLETE')
+        return True
+
     def describe_stacks(self, name_or_stack_id):
         stacks = self.stacks.values()
         if name_or_stack_id:

moto/cloudformation/responses.py

@@ -118,6 +118,24 @@ class CloudFormationResponse(BaseResponse):
             template = self.response_template(CREATE_CHANGE_SET_RESPONSE_TEMPLATE)
             return template.render(stack_id=stack_id, change_set_id=change_set_id)
 
+    @amzn_request_id
+    def execute_change_set(self):
+        stack_name = self._get_param('StackName')
+        change_set_name = self._get_param('ChangeSetName')
+        self.cloudformation_backend.execute_change_set(
+            stack_name=stack_name,
+            change_set_name=change_set_name,
+        )
+        if self.request_json:
+            return json.dumps({
+                'ExecuteChangeSetResponse': {
+                    'ExecuteChangeSetResult': {},
+                }
+            })
+        else:
+            template = self.response_template(EXECUTE_CHANGE_SET_RESPONSE_TEMPLATE)
+            return template.render()
+
     def describe_stacks(self):
         stack_name_or_id = None
         if self._get_param('StackName'):
@@ -302,6 +320,16 @@ CREATE_CHANGE_SET_RESPONSE_TEMPLATE = """<CreateStackResponse>
 </CreateStackResponse>
 """
 
+EXECUTE_CHANGE_SET_RESPONSE_TEMPLATE = """<ExecuteChangeSetResponse>
+  <ExecuteChangeSetResult>
+      <ExecuteChangeSetResult/>
+  </ExecuteChangeSetResult>
+  <ResponseMetadata>
+    <RequestId>{{ request_id }}</RequestId>
+  </ResponseMetadata>
+</ExecuteChangeSetResponse>
+"""
+
 DESCRIBE_STACKS_TEMPLATE = """<DescribeStacksResponse>
   <DescribeStacksResult>
     <Stacks>

tests/test_cloudformation/test_cloudformation_stack_crud_boto3.py

@@ -337,6 +337,30 @@ def test_create_change_set_from_s3_url():
     assert 'arn:aws:cloudformation:us-east-1:123456789:stack/NewStack' in response['StackId']
 
 
+@mock_cloudformation
+def test_execute_change_set_w_arn():
+    cf_conn = boto3.client('cloudformation', region_name='us-east-1')
+    change_set = cf_conn.create_change_set(
+        StackName='NewStack',
+        TemplateBody=dummy_template_json,
+        ChangeSetName='NewChangeSet',
+        ChangeSetType='CREATE',
+    )
+    cf_conn.execute_change_set(ChangeSetName=change_set['Id'])
+
+
+@mock_cloudformation
+def test_execute_change_set_w_name():
+    cf_conn = boto3.client('cloudformation', region_name='us-east-1')
+    change_set = cf_conn.create_change_set(
+        StackName='NewStack',
+        TemplateBody=dummy_template_json,
+        ChangeSetName='NewChangeSet',
+        ChangeSetType='CREATE',
+    )
+    cf_conn.execute_change_set(ChangeSetName='NewStack', StackName='NewStack')
+
+
 @mock_cloudformation
 def test_describe_stack_pagination():
     conn = boto3.client('cloudformation', region_name='us-east-1')