Don't copy exception classes

see:
http://stackoverflow.com/questions/9541025/how-to-copy-a-python-class
https://review.openstack.org/194487

This simplifies the method so it just re-raises local exceptions
and if it is Remote, raises ResourceFailure.

Closes-Bug: #1474153

Change-Id: I9c4dcadcbcf6abe6ff71dbcdccaae4706b684a83

heat/engine/resources/stack_resource.py

@@ -11,7 +11,6 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import copy
 import hashlib
 import json
 
@@ -298,20 +297,6 @@ class StackResource(resource.Resource):
         self.resource_id_set(result['stack_id'])
 
     def raise_local_exception(self, ex):
-        ex_type = ex.__class__.__name__
-
-        is_remote = ex_type.endswith('_Remote')
-        if is_remote:
-            ex_type = ex_type[:-len('_Remote')]
-
-        full_message = six.text_type(ex)
-        if full_message.find('\n') > -1 and is_remote:
-            message, msg_trace = full_message.split('\n', 1)
-        elif isinstance(ex, exception.HeatException):
-            message = ex.message
-        else:
-            message = full_message
-
         if (isinstance(ex, exception.ActionInProgress) and
                 self.stack.action == self.stack.ROLLBACK):
             # The update was interrupted and the rollback is already in
@@ -319,12 +304,16 @@ class StackResource(resource.Resource):
             # finish
             return
 
-        if hasattr(exception, ex_type):
-            local_ex = copy.copy(getattr(exception, ex_type))
-            local_ex.msg_fmt = "%(message)s"
-            raise local_ex(message=message)
+        if not ex.__class__.__name__.endswith('_Remote'):
+            raise ex
+
+        full_message = six.text_type(ex)
+        if full_message.find('\n') > -1:
+            message, msg_trace = full_message.split('\n', 1)
         else:
-            raise exception.ResourceFailure(ex, self, 'remote')
+            message = full_message
+
+        raise exception.ResourceFailure(message, self, action=self.action)
 
     def check_create_complete(self, cookie=None):
         return self._check_status_complete(resource.Resource.CREATE)

heat/tests/test_stack_resource.py

@@ -868,11 +868,13 @@ class RaiseLocalException(StackResourceBaseTest):
 
     def test_messaging_timeout(self):
         local = msg_exceptions.MessagingTimeout('took too long')
-        self.assertRaises(exception.ResourceFailure,
+        self.assertRaises(msg_exceptions.MessagingTimeout,
                           self.parent_resource.raise_local_exception, local)
 
     def test_remote_heat_ex(self):
-        InvalidResourceType_Remote = exception.InvalidResourceType
+        class InvalidResourceType_Remote(exception.InvalidResourceType):
+            pass
+
         local = InvalidResourceType_Remote(message='test')
-        self.assertRaises(exception.InvalidResourceType,
+        self.assertRaises(exception.ResourceFailure,
                           self.parent_resource.raise_local_exception, local)