Check if a exception has a code on it before read the code

In 'nova.volume.cinder.API.initialize_connection' method, all exceptions
threw by 'terminate_connection' will be caught and logged. When log the
exceptions, the code try to record the 'code' attribute of the exception
since the code is expecting a CinderClientException or NovaException[1].
But if the some else exception(like TypeError) which doesn't have a code
on it was threw up, we will got a AttributeError.

This commit add logic to check if the exception has a code on it before
try to read it.

[1]https://github.com/openstack/nova/blob/13.0.0.0rc3/nova/volume/cinder.py#L437

Change-Id: I42fd2f2b77c41a60dfaf0cc882a344596d50daf5
Closes-Bug: #1564551
(cherry picked from commit 2135a3f55f)

nova/tests/unit/volume/test_cinder.py

@@ -293,6 +293,25 @@ class CinderApiTestCase(test.NoDBTestCase):
         mock_cinderclient.return_value.volumes. \
             initialize_connection.assert_called_once_with(volume_id, connector)
 
+    @mock.patch('nova.volume.cinder.LOG')
+    @mock.patch('nova.volume.cinder.cinderclient')
+    def test_initialize_connection_exception_no_code(
+                                self, mock_cinderclient, mock_log):
+        mock_cinderclient.return_value.volumes. \
+            initialize_connection.side_effect = (
+                cinder_exception.ClientException(500, "500"))
+        mock_cinderclient.return_value.volumes. \
+            terminate_connection.side_effect = (
+                test.TestingException)
+
+        connector = {'host': 'fakehost1'}
+        self.assertRaises(cinder_exception.ClientException,
+                          self.api.initialize_connection,
+                          self.ctx,
+                          'id1',
+                          connector)
+        self.assertIsNone(mock_log.error.call_args_list[1][0][1]['code'])
+
     @mock.patch('nova.volume.cinder.cinderclient')
     def test_initialize_connection_rollback(self, mock_cinderclient):
         mock_cinderclient.return_value.volumes.\

nova/volume/cinder.py

@@ -366,7 +366,8 @@ class API(object):
                               {'vol': volume_id,
                                'host': connector.get('host'),
                                'msg': six.text_type(exc),
-                               'code': exc.code})
+                               'code': (
+                                exc.code if hasattr(exc, 'code') else None)})
 
     @translate_volume_exception
     def terminate_connection(self, context, volume_id, connector):