Skip security group code when there is no network.

This patch adds a simple check to the nova/quantum API that immediately
returns an empty list if there are no configured networks available.

Fixes bug 1191044

Change-Id: I34ac4dd56c71f99c7ed9ff632d6dc7036d91008d

2 files changed, 18 insertions, 0 deletions

diff --git a/nova/network/quantumv2/api.py b/nova/network/quantumv2/api.py
index 054611cd3..e28d86b0e 100644
--- a/nova/network/quantumv2/api.py
+++ b/nova/network/quantumv2/api.py
@@ -184,6 +184,11 @@ class API(base.Base):
 
         nets = self._get_available_networks(context, instance['project_id'],
                                             net_ids)
+
+        if not nets:
+            LOG.warn(_("No network configured!"), instance=instance)
+            return []
+
         security_groups = kwargs.get('security_groups', [])
         security_group_ids = []
 
diff --git a/nova/tests/network/test_quantumv2.py b/nova/tests/network/test_quantumv2.py
index 0b6f184ae..b8cadc8d6 100644
--- a/nova/tests/network/test_quantumv2.py
+++ b/nova/tests/network/test_quantumv2.py
@@ -607,6 +607,19 @@ class TestQuantumv2(test.TestCase):
         self._allocate_for_instance(net_idx=1,
                                     requested_networks=requested_networks)
 
+    def test_allocate_for_instance_no_networks(self):
+        """verify the exception thrown when there are no networks defined."""
+        api = quantumapi.API()
+        self.moxed_client.list_networks(
+            tenant_id=self.instance['project_id'],
+            shared=False).AndReturn(
+                {'networks': []})
+        self.moxed_client.list_networks(shared=True).AndReturn(
+            {'networks': []})
+        self.mox.ReplayAll()
+        nwinfo = api.allocate_for_instance(self.context, self.instance)
+        self.assertEqual(len(nwinfo), 0)
+
     def test_allocate_for_instance_ex1(self):
         """verify we will delete created ports
         if we fail to allocate all net resources.