heat API : return ResourceProperties as JSON

For boto to correctly parse the API DescribeStackEvents
action, the ResourceProperties key in the response
must be a string, as per the AWS spec, so we encode the
properties in a JSON blob

Fixes #245

Change-Id: Icd38984836a941ed4a012b06382933bb46f43c4f
Signed-off-by: Steven Hardy <shardy@redhat.com>

heat/api/cfn/v1/stacks.py

@@ -426,6 +426,8 @@ class StackController(object):
             }
 
             result = api_utils.reformat_dict_keys(keymap, e)
+            result['ResourceProperties'] = json.dumps(
+                                           result['ResourceProperties'])
 
             return self._stackid_format(result)
 

heat/tests/test_api_cfn_v1.py

@@ -808,7 +808,7 @@ class StackControllerTest(unittest.TestCase):
                 'ResourceType': u'AWS::EC2::Instance',
                 'Timestamp': u'2012-07-23T13:05:39Z',
                 'StackName': u'wordpress',
-                'ResourceProperties': {u'UserData': u'blah'},
+                'ResourceProperties': json.dumps({u'UserData': u'blah'}),
                 'PhysicalResourceId': None,
                 'ResourceStatusReason': u'state changed',
                 'LogicalResourceId': u'WikiDatabase'}]}}}