gistfile1.txt

diff --git a/rally/benchmark/scenarios/nova/servers.py b/rally/benchmark/scenarios/nova/servers.py
index f4dbcb9..14b64bc 100644
--- a/rally/benchmark/scenarios/nova/servers.py
+++ b/rally/benchmark/scenarios/nova/servers.py
@@ -13,8 +13,6 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.

-import random
-
 import jsonschema

 from rally.benchmark.scenarios import base as scenario_base
@@ -142,33 +140,24 @@ class NovaServers(utils.NovaScenario,
     @validation.add(validation.image_valid_on_flavor("flavor", "image"))
     @scenario_base.scenario(context={"cleanup": ["nova"]})
     @validation.required_services(consts.Service.NOVA)
-    def boot_server(self, image, flavor, **kwargs):
+    def boot_server(self, image, flavor, auto_assign_nic=False,  **kwargs):
         """Test VM boot - assumed clean-up is done elsewhere."""
-        if 'nics' not in kwargs:
-            nets = self.clients("nova").networks.list()
-            if nets:
-                random_nic = random.choice(nets)
-                kwargs['nics'] = [{'net-id': random_nic.id}]
-        self._boot_server(
-            self._generate_random_name(), image, flavor, **kwargs)
+        server_name = self._generate_random_name()
+        self._boot_server(server_name, image, flavor, auto_assign_nic,
+                          **kwargs)

     @types.set(image=types.ImageResourceType,
                flavor=types.FlavorResourceType)
     @validation.add(validation.image_valid_on_flavor("flavor", "image"))
     @scenario_base.scenario(context={"cleanup": ["nova", "cinder"]})
     @validation.required_services(consts.Service.NOVA, consts.Service.CINDER)
-    def boot_server_from_volume(self, image, flavor,
-                                volume_size, **kwargs):
+    def boot_server_from_volume(self, image, flavor, volume_size,
+                                auto_assign_nic=False, **kwargs):
         """Test VM boot from volume - assumed clean-up is done elsewhere."""
-        if 'nics' not in kwargs:
-            nets = self.clients("nova").networks.list()
-            if nets:
-                random_nic = random.choice(nets)
-                kwargs['nics'] = [{'net-id': random_nic.id}]
         volume = self._create_volume(volume_size, imageRef=image)
         block_device_mapping = {'vda': '%s:::1' % volume.id}
         self._boot_server(self._generate_random_name(),
-                          image, flavor,
+                          image, flavor, auto_assign_nic,
                           block_device_mapping=block_device_mapping,
                           **kwargs)

diff --git a/rally/benchmark/scenarios/nova/utils.py b/rally/benchmark/scenarios/nova/utils.py
index c2e83ad..cd2c6ab 100644
--- a/rally/benchmark/scenarios/nova/utils.py
+++ b/rally/benchmark/scenarios/nova/utils.py
@@ -74,7 +74,8 @@ class NovaScenario(scenario_base.Scenario):
         return self.clients("nova").servers.list(detailed)

     @scenario_base.atomic_action_timer('nova.boot_server')
-    def _boot_server(self, server_name, image_id, flavor_id, **kwargs):
+    def _boot_server(self, server_name, image_id, flavor_id,
+                     auto_assign_nic=False, **kwargs):
         """Boots one server.

         Returns when the server is actually booted and is in the "Active"
@@ -97,15 +98,19 @@ class NovaScenario(scenario_base.Scenario):
             elif allow_ssh_secgroup not in kwargs['security_groups']:
                 kwargs['security_groups'].append(allow_ssh_secgroup)

-        nets = self.clients("nova").networks.list()
-        fip_pool = [
-                    pool.name
-                    for pool in self.clients("nova").floating_ip_pools.list()
-                   ]
-        for net in nets:
-            if net.label not in fip_pool:
-                kwargs['nics'] = [{'net-id': net.id}]
-                break
+        nics = kwargs.get('nics', False)
+
+        if auto_assign_nic and nics is False:
+            nets = self.clients("nova").networks.list()
+            fip_pool = [
+                        pool.name
+                        for pool in
+                            self.clients("nova").floating_ip_pools.list()
+                       ]
+            for net in nets:
+                if net.label not in fip_pool:
+                    kwargs['nics'] = [{'net-id': net.id}]
+                    break

         server = self.clients("nova").servers.create(server_name, image_id,
                                                      flavor_id, **kwargs)
diff --git a/tests/benchmark/scenarios/nova/test_servers.py b/tests/benchmark/scenarios/nova/test_servers.py
index 74fb866..4f575c9 100644
--- a/tests/benchmark/scenarios/nova/test_servers.py
+++ b/tests/benchmark/scenarios/nova/test_servers.py
@@ -14,6 +14,7 @@
 #    under the License.

 import mock
+import random

 from rally.benchmark.scenarios.nova import servers
 from rally import exceptions as rally_exceptions
@@ -247,7 +248,7 @@ class NovaServersTestCase(test.TestCase):

         return scenario, kwargs, expected_kwargs

-    @mock.patch("rally.benchmark.scenarios.nova.servers.random.choice")
+    @mock.patch("random.choice")
     def _verify_boot_server(self, mock_choice, mock_osclients, nic=None,
                             assert_nic=False):
         scenario, kwargs, expected_kwargs = self._prepare_boot(
@@ -256,7 +257,7 @@ class NovaServersTestCase(test.TestCase):
             nic=nic, assert_nic=assert_nic)

         scenario.boot_server("img", 0, **kwargs)
-        scenario._boot_server.assert_called_once_with("name", "img", 0,
+        scenario._boot_server.assert_called_once_with("name", "img", 0, False,
                                                       **expected_kwargs)

     @mock.patch("rally.benchmark.scenarios.nova.servers.NovaServers.clients")
@@ -271,35 +272,6 @@ class NovaServersTestCase(test.TestCase):
         self._verify_boot_server(mock_osclients=mock_osclients,
                                  nic=[{'net-id': 'net-1'}], assert_nic=True)

-    @mock.patch("rally.benchmark.scenarios.nova.servers.NovaServers.clients")
-    @mock.patch("rally.benchmark.runners.base.osclients")
-    def test_boot_server_random_nic(self, mock_osclients, mock_nova_clients):
-        self._verify_boot_server(mock_osclients=mock_osclients, nic=None,
-                                 assert_nic=True)
-
-    @mock.patch("rally.benchmark.scenarios.nova.servers.NovaServers.clients")
-    @mock.patch("rally.benchmark.runners.base.osclients")
-    @mock.patch("rally.benchmark.scenarios.nova.servers.random.choice")
-    def test_boot_server_from_volume_random_nic(self, mock_choice,
-                                                mock_osclients,
-                                                mock_nova_clients):
-        scenario, kwargs, expected_kwargs = self._prepare_boot(
-            mock_osclients=mock_osclients,
-            mock_choice=mock_choice,
-            nic=None, assert_nic=True)
-
-        fake_volume = fakes.FakeVolumeManager().create()
-        fake_volume.id = "volume_id"
-        scenario._create_volume = mock.MagicMock(return_value=fake_volume)
-
-        scenario.boot_server_from_volume("img", 0, 5, **kwargs)
-
-        scenario._create_volume.assert_called_once_with(5, imageRef="img")
-        scenario._boot_server.assert_called_once_with(
-                    "name", "img", 0,
-                    block_device_mapping={"vda": "volume_id:::1"},
-                    **expected_kwargs)
-
     def test_snapshot_server(self):
         fake_server = object()
         fake_image = fakes.FakeImageManager()._create()