Fix get_segments_id with subnets without segment_id

Unfortunatly when we merged Ie166f3b51fddeaf916cda7c5ac34bbcdda0fd17a we
forgot that subnets can have no segment_id field.

Change-Id: Idb35b7e3c69fe8efe498abe4ebcc6cad8918c4ed
Closes-Bug: #2018375

2 files changed, 18 insertions, 2 deletions

diff --git a/nova/network/neutron.py b/nova/network/neutron.py
index 6c9f19f010..0ae0f4099f 100644
--- a/nova/network/neutron.py
+++ b/nova/network/neutron.py
@@ -3907,7 +3907,7 @@ class API:
                 'Failed to get segment IDs for network %s' % network_id) from e
         # The segment field of an unconfigured subnet could be None
         return [subnet['segment_id'] for subnet in subnets
-                                     if subnet['segment_id'] is not None]
+                                     if subnet.get('segment_id') is not None]
 
     def get_segment_id_for_subnet(
         self,
diff --git a/nova/tests/unit/network/test_neutron.py b/nova/tests/unit/network/test_neutron.py
index eefa7b974f..9aa970aca1 100644
--- a/nova/tests/unit/network/test_neutron.py
+++ b/nova/tests/unit/network/test_neutron.py
@@ -7415,7 +7415,7 @@ class TestAPI(TestAPIBase):
             network_id=uuids.network_id, fields='segment_id')
 
     @mock.patch.object(neutronapi, 'get_client')
-    def test_get_segment_ids_for_network_with_no_segments(self, mock_client):
+    def test_get_segment_ids_for_network_with_segments_none(self, mock_client):
         subnets = {'subnets': [{'segment_id': None}]}
         mocked_client = mock.create_autospec(client.Client)
         mock_client.return_value = mocked_client
@@ -7431,6 +7431,22 @@ class TestAPI(TestAPIBase):
             network_id=uuids.network_id, fields='segment_id')
 
     @mock.patch.object(neutronapi, 'get_client')
+    def test_get_segment_ids_for_network_with_no_segments(self, mock_client):
+        subnets = {'subnets': [{}]}
+        mocked_client = mock.create_autospec(client.Client)
+        mock_client.return_value = mocked_client
+        mocked_client.list_subnets.return_value = subnets
+        with mock.patch.object(
+            self.api, 'has_segment_extension', return_value=True,
+        ):
+            res = self.api.get_segment_ids_for_network(
+                self.context, uuids.network_id)
+        self.assertEqual([], res)
+        mock_client.assert_called_once_with(self.context, admin=True)
+        mocked_client.list_subnets.assert_called_once_with(
+            network_id=uuids.network_id, fields='segment_id')
+
+    @mock.patch.object(neutronapi, 'get_client')
     def test_get_segment_ids_for_network_fails(self, mock_client):
         mocked_client = mock.create_autospec(client.Client)
         mock_client.return_value = mocked_client