swift: Do not search storage_url for ks v2

Previously, we introduced a re-auth approach for swift store.
In case of single-tenant store we stated that it works with
Keystone v3 only when re-authenticating but we also need to make
the same restriction when receiving swift endpoint from keystone
becase it breaks some installations where auth_url contains
trailing slash.

So now if auth_version is not v3 then we don't search endpoint url
from Keystone in this case and simply return None. It is safe
because we don't do any re-authentication for v1 or v2 and use
old methods for that version.

Change-Id: Id8dab9ed74eef56ffa4937bf29f96888b673ad64
Closes-Bug: #1552132

glance_store/_drivers/swift/connection_manager.py

@@ -19,6 +19,7 @@ connection with valid credentials and updated token"""
 import logging
 
 from keystoneclient import exceptions as ks_exceptions
+from oslo_utils import encodeutils
 
 from glance_store import exceptions
 from glance_store.i18n import _
@@ -137,11 +138,26 @@ class SwiftConnectionManager(object):
 
 class SingleTenantConnectionManager(SwiftConnectionManager):
     def _get_storage_url(self):
-        return self.client.session.get_endpoint(
-            service_type=self.store.service_type,
-            interface=self.store.endpoint_type,
-            region_name=self.store.region
-        )
+        """Get swift endpoint from keystone
+
+        Return endpoint for swift from service catalog. The method works only
+        Keystone v3. If you are using different version (1 or 2)
+        it returns None.
+        :return: swift endpoint
+        """
+        if self.store.auth_version == '3':
+            try:
+                return self.client.session.get_endpoint(
+                    service_type=self.store.service_type,
+                    interface=self.store.endpoint_type,
+                    region_name=self.store.region
+                )
+            except Exception as e:
+                # do the same that swift driver does
+                # when catching ClientException
+                msg = _("Cannot find swift service endpoint : "
+                        "%s") % encodeutils.exception_to_unicode(e)
+                raise exceptions.BackendException(msg)
 
     def _init_connection(self):
         if self.store.auth_version == '3':

glance_store/tests/unit/test_swift_store.py

@@ -22,7 +22,6 @@ import mock
 import tempfile
 import uuid
 
-from keystoneclient import exceptions as ks_exceptions
 from oslo_config import cfg
 from oslo_utils import encodeutils
 from oslo_utils import units
@@ -974,6 +973,8 @@ class SwiftTests(object):
         conf = copy.deepcopy(SWIFT_CONF)
         self.config(**conf)
         moves.reload_module(swift)
+        # mock client because v3 uses it to receive auth_info
+        self.mock_keystone_client()
         self.store = Store(self.conf)
         self.store.configure()
 
@@ -981,7 +982,7 @@ class SwiftTests(object):
         loc = location.get_location_from_uri(uri, conf=self.conf)
         self.store.delete(loc)
 
-        self.assertRaises(ks_exceptions.NotFound, self.store.get, loc)
+        self.assertRaises(exceptions.NotFound, self.store.get, loc)
 
     def test_delete_non_existing(self):
         """