Fix duplicated queues on multi pools

Now we're saving queues on management plane, so it's not necessary
to interate all the pools to list queues. This patch fixes the issue
and adds a test for that.

Closes-Bug: #1490807

Change-Id: I595f240d2944c55c2f4883bbc3070aaf25c19763

zaqar/storage/pooling.py

@@ -146,13 +146,14 @@ class QueueController(storage.Queue):
 
         def all_pages():
             cursor = self._pool_catalog._pools_ctrl.list(limit=0)
-            for pool in next(cursor):
-                yield next(self._pool_catalog.get_driver(pool['name'])
-                           .queue_controller.list(
-                               project=project,
-                               marker=marker,
-                               limit=limit,
-                               detailed=detailed))
+            pools_list = list(next(cursor))
+            anypool = pools_list and pools_list[0]
+            yield next(self._pool_catalog.get_driver(anypool['name'])
+                       .queue_controller.list(
+                           project=project,
+                           marker=marker,
+                           limit=limit,
+                           detailed=detailed))
 
         # make a heap compared with 'name'
         ls = heapq.merge(*[

zaqar/tests/unit/storage/test_pool_catalog.py

@@ -12,6 +12,7 @@
 # License for the specific language governing permissions and limitations under
 # the License.
 
+import mock
 import uuid
 
 from zaqar.openstack.common.cache import cache as oslo_cache
@@ -96,3 +97,15 @@ class PoolCatalogTest(testing.TestBase):
                           self.catalog.register,
                           'test', project=self.project,
                           flavor='fake')
+
+    def test_queues_list_on_multi_pools(self):
+        def fake_list(project=None, marker=None, limit=10, detailed=False):
+            yield iter([{'name': 'fake_queue'}])
+
+        list_str = 'zaqar.storage.mongodb.queues.QueueController.list'
+        with mock.patch(list_str) as queues_list:
+            queues_list.side_effect = fake_list
+            queue_controller = pooling.QueueController(self.catalog)
+            result = queue_controller.list(project=self.project)
+            queue_list = list(next(result))
+            self.assertEqual(1, len(queue_list))