Fix semantic validation of context images

In the semantic validation of the images context it was assumed that the
parameter users is a dictionary that contains the key endpoint, whereas
users is a list of Clients objects. This was leading to a validation
error and any benchmark scenario that had in its configuration file this
context was failing.

Closes-Bug: 1356336
Change-Id: I6452a47975cd3adcd31ec7b7c4ca0159aec8776f

rally-scenarios/rally.yaml

@@ -642,6 +642,24 @@
       sla:
         max_failure_percent: 0
 
+  GlanceImages.list_images:
+    -
+      runner:
+        type: "constant"
+        times: 5
+        concurrency: 5
+      context:
+        users:
+          tenants: 2
+          users_per_tenant: 2
+        images:
+          image_url: "http://download.cirros-cloud.net/0.3.1/cirros-0.3.1-x86_64-disk.img"
+          image_type: "qcow2"
+          image_container: "bare"
+          images_per_tenant: 2
+      sla:
+        max_failure_percent: 0
+
   NovaServers.boot_and_delete_server:
     -
       args:

rally/benchmark/context/images.py

@@ -104,9 +104,8 @@ class ImageGenerator(base.Context):
     @classmethod
     def validate_semantic(cls, config, admin, users, task):
         """Check if the image service is available."""
-
         try:
-            glance = osclients.Clients(users[0]["endpoint"]).glance()
+            glance = users[0].glance()
             list(glance.images.list(limit=0))
         except Exception as e:
             message = _(

tests/benchmark/context/test_images.py

@@ -141,26 +141,13 @@ class ImageGeneratorTestCase(test.TestCase):
         mock_image_remover.side_effect = Exception('failed_deletion')
         self.assertRaises(exceptions.ImageCleanUpException, images_ctx.cleanup)
 
-    @mock.patch("%s.images.osclients" % CTX)
-    def test_validate_semantic(self, mock_osclients):
-        user_key = [{'id': i, 'tenant_id': j, 'endpoint': 'endpoint'}
-                    for j in range(2)
-                    for i in range(5)]
+    def test_validate_semantic(self):
+        users = [fakes.FakeClients()]
+        images.ImageGenerator.validate_semantic(None, None, users, None)
 
-        fc = fakes.FakeClients()
-        mock_osclients.Clients.return_value = fc
-        images.ImageGenerator.validate_semantic(None, None,
-                                                user_key, None)
-
-    @mock.patch("%s.images.osclients" % CTX)
-    def test_validate_semantic_unavailabe(self, mock_osclients):
-        user_key = [{'id': i, 'tenant_id': j, 'endpoint': 'endpoint'}
-                    for j in range(2)
-                    for i in range(5)]
-
-        endpoint = mock.MagicMock()
-        (mock_osclients.Clients(endpoint).glance().images.list.
-            side_effect) = Exception('list_error')
+    @mock.patch("%s.images.osclients.Clients.glance" % CTX)
+    def test_validate_semantic_unavailabe(self, mock_glance):
+        mock_glance.side_effect = Exception("list error")
         self.assertRaises(exceptions.InvalidScenarioArgument,
                           images.ImageGenerator.validate_semantic, None, None,
-                          user_key, None)
+                          None, None)