Fixes issue #575: cloudformation update_stack response ResponseParserError.

moto/cloudformation/models.py

@@ -51,6 +51,7 @@ class FakeStack(object):
         self.template = template
         self.resource_map.update(json.loads(template))
         self.output_map = self._create_output_map()
+        self.status = 'UPDATE_COMPLETE'
 
     def delete(self):
         self.resource_map.delete()

moto/cloudformation/responses.py

@@ -130,14 +130,18 @@ class CloudFormationResponse(BaseResponse):
             name=stack_name,
             template=stack_body,
         )
-        stack_body = {
+
-            'UpdateStackResponse': {
+        if self.request_json:
-                'UpdateStackResult': {
+            return json.dumps({
-                    'StackId': stack.name,
+                'UpdateStackResponse': {
+                    'UpdateStackResult': {
+                        'StackId': stack.name,
+                    }
                 }
-            }
+            })
-        }
+        else:
-        return json.dumps(stack_body)
+            template = self.response_template(UPDATE_STACK_RESPONSE_TEMPLATE)
+            return template.render(stack=stack)
 
     def delete_stack(self):
         name_or_stack_id = self.querystring.get('StackName')[0]
@@ -164,6 +168,15 @@ CREATE_STACK_RESPONSE_TEMPLATE = """<CreateStackResponse>
 </CreateStackResponse>
 """
 
+UPDATE_STACK_RESPONSE_TEMPLATE = """<UpdateStackResponse>
+  <UpdateStackResult>
+    <StackId>{{ stack.stack_id }}</StackId>
+  </UpdateStackResult>
+  <ResponseMetadata>
+    <RequestId>b9b5b068-3a41-11e5-94eb-example</RequestId>
+    </ResponseMetadata>
+</UpdateStackResponse>
+"""
 
 DESCRIBE_STACKS_TEMPLATE = """<DescribeStacksResponse>
   <DescribeStacksResult>

tests/test_cloudformation/test_cloudformation_stack_crud.py

@@ -263,24 +263,24 @@ def test_stack_tags():
     dict(stack.tags).should.equal({"foo": "bar", "baz": "bleh"})
 
 
-# @mock_cloudformation
+@mock_cloudformation
-# def test_update_stack():
+def test_update_stack():
-#     conn = boto.connect_cloudformation()
+    conn = boto.connect_cloudformation()
-#     conn.create_stack(
+    conn.create_stack(
-#         "test_stack",
+        "test_stack",
-#         template_body=dummy_template_json,
+        template_body=dummy_template_json,
-#     )
+    )
 
-#     conn.update_stack("test_stack", dummy_template_json2)
+    conn.update_stack("test_stack", dummy_template_json2)
 
-#     stack = conn.describe_stacks()[0]
+    stack = conn.describe_stacks()[0]
-#     stack.get_template().should.equal({
+    stack.get_template().should.equal({
-#         'GetTemplateResponse': {
+        'GetTemplateResponse': {
-#             'GetTemplateResult': {
+            'GetTemplateResult': {
-#                 'TemplateBody': dummy_template_json2,
+                'TemplateBody': dummy_template_json2,
-#                 'ResponseMetadata': {
+                'ResponseMetadata': {
-#                     'RequestId': '2d06e36c-ac1d-11e0-a958-f9382b6eb86bEXAMPLE'
+                    'RequestId': '2d06e36c-ac1d-11e0-a958-f9382b6eb86bEXAMPLE'
-#                 }
+                }
-#             }
+            }
-#         }
+        }
-#     })
+    })

tests/test_cloudformation/test_cloudformation_stack_crud_boto3.py

@@ -19,7 +19,27 @@ dummy_template = {
     "Resources": {},
 }
 
+dummy_update_template = {
+    "AWSTemplateFormatVersion": "2010-09-09",
+    "Parameters": {
+        "KeyName": {
+            "Description": "Name of an existing EC2 KeyPair",
+            "Type": "AWS::EC2::KeyPair::KeyName",
+            "ConstraintDescription": "must be the name of an existing EC2 KeyPair."
+        }
+    },
+    "Resources": {
+        "Instance": {
+            "Type": "AWS::EC2::Instance",
+            "Properties": {
+                "ImageId": "ami-08111162"
+            }
+        }
+    }
+}
+
 dummy_template_json = json.dumps(dummy_template)
+dummy_update_template_json = json.dumps(dummy_template)
 
 @mock_cloudformation
 def test_boto3_create_stack():
@@ -169,6 +189,25 @@ def test_describe_deleted_stack():
     stack_by_id['StackName'].should.equal("test_stack")
     stack_by_id['StackStatus'].should.equal("DELETE_COMPLETE")
 
+@mock_cloudformation
+def test_describe_updated_stack():
+    cf_conn = boto3.client('cloudformation', region_name='us-east-1')
+    cf_conn.create_stack(
+        StackName="test_stack",
+        TemplateBody=dummy_template_json,
+    )
+
+    cf_conn.update_stack(
+        StackName="test_stack",
+        TemplateBody=dummy_update_template_json)
+
+    stack = cf_conn.describe_stacks(StackName="test_stack")['Stacks'][0]
+    stack_id = stack['StackId']
+    stack_by_id = cf_conn.describe_stacks(StackName=stack_id)['Stacks'][0]
+    stack_by_id['StackId'].should.equal(stack['StackId'])
+    stack_by_id['StackName'].should.equal("test_stack")
+    stack_by_id['StackStatus'].should.equal("UPDATE_COMPLETE")
+
 
 @mock_cloudformation
 def test_bad_describe_stack():