Use six.test_type instead str format

Change-Id: I74139f2acfd3e0dd48372ba7cb49d8932973589c
Signed-off-by: Yuanbin.Chen <cybing4@gmail.com>

zun/container/docker/utils.py

@@ -99,5 +99,5 @@ class DockerHTTPClient(docker.APIClient):
         except errors.APIError as e:
             if "process not found for container" in str(e):
                 raise exception.Invalid(_(
-                    "no such exec instance: %s") % str(e))
+                    "no such exec instance: %s") % six.text_type(e))
             raise

zun/image/docker/driver.py

@@ -41,7 +41,7 @@ class DockerDriver(driver.ContainerImageDriver):
             except errors.ImageNotFound:
                 return
             except errors.APIError as api_error:
-                raise exception.ZunException(str(api_error))
+                raise exception.ZunException(six.text_type(api_error))
             except Exception as e:
                 LOG.exception('Unknown exception occurred while deleting '
                               'image %s in glance:%s',
@@ -103,7 +103,7 @@ class DockerDriver(driver.ContainerImageDriver):
                 # TODO(hongbin): search image by both repo and tag
                 images = docker.search(repo)
             except errors.APIError as api_error:
-                raise exception.ZunException(str(api_error))
+                raise exception.ZunException(six.text_type(api_error))
             except Exception as e:
                 msg = _('Cannot search image in docker: {0}')
                 raise exception.ZunException(msg.format(e))

zun/image/driver.py

@@ -12,6 +12,7 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+import six
 import sys
 
 from oslo_log import log as logging
@@ -50,7 +51,7 @@ def load_image_driver(image_driver=None):
 
         if not isinstance(driver, ContainerImageDriver):
             raise Exception(_('Expected driver of type: %s') %
-                            str(ContainerImageDriver))
+                            six.text_type(ContainerImageDriver))
 
         return driver
     except Exception:

zun/volume/cinder_workflow.py

@@ -10,6 +10,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import six
+
 from cinderclient import exceptions as cinder_exception
 from os_brick import exception as os_brick_exception
 from os_brick.initiator import connector as brick_connector
@@ -151,7 +153,8 @@ class CinderWorkflow(object):
         try:
             cinder_api.begin_detaching(volume_id)
         except cinder_exception.BadRequest as e:
-            raise exception.Invalid(_("Invalid volume: %s") % str(e))
+            raise exception.Invalid(_("Invalid volume: %s") %
+                                    six.text_type(e))
 
         conn_info = jsonutils.loads(volume.connection_info)
         try:
@@ -172,4 +175,5 @@ class CinderWorkflow(object):
         try:
             cinder_api.delete_volume(volume_id)
         except cinder_exception as e:
-            raise exception.Invalid(_("Delete Volume failed: %s") % str(e))
+            raise exception.Invalid(_("Delete Volume failed: %s") %
+                                    six.text_type(e))