Fix nic order not correct after reboot

Previously if an instance was rebooted or migrated the original nic order
would not be maintained. This patch retrieves the correct nic order from
info_cache so that the order is mantained.

Fixes bug 1187092

Change-Id: I3f5488cc14c692fde7d5bd3376389e2f2f5550ff
(cherry picked from commit bcd12a7)

nova/network/quantumv2/api.py

@@ -31,6 +31,7 @@
 from nova.network import quantumv2
 from nova.network.security_group import openstack_driver
 from nova.openstack.common import excutils
+from nova.openstack.common import jsonutils
 from nova.openstack.common import log as logging
 from nova.openstack.common import uuidutils
 
@@ -792,12 +793,18 @@ def _build_network_info_model(self, context, instance, networks=None):
         data = client.list_ports(**search_opts)
         ports = data.get('ports', [])
         if networks is None:
+            # retrieve networks from info_cache to get correct nic order
+            network_cache = self.conductor_api.instance_get_by_uuid(
+                context, instance['uuid'])['info_cache']['network_info']
+            network_cache = jsonutils.loads(network_cache)
+            net_ids = [iface['network']['id'] for iface in network_cache]
             networks = self._get_available_networks(context,
                                                     instance['project_id'])
 
         # ensure ports are in preferred network order, and filter out
         # those not attached to one of the provided list of networks
-        net_ids = [n['id'] for n in networks]
+        else:
+            net_ids = [n['id'] for n in networks]
         ports = [port for port in ports if port['network_id'] in net_ids]
         _ensure_requested_network_ordering(lambda x: x['network_id'],
                                            ports, net_ids)

nova/tests/network/test_quantumv2.py

@@ -23,11 +23,13 @@
 from quantumclient.v2_0 import client
 
 from nova.compute import instance_types
+from nova.conductor import api as conductor_api
 from nova import context
 from nova import exception
 from nova.network import model
 from nova.network import quantumv2
 from nova.network.quantumv2 import api as quantumapi
+from nova.openstack.common import jsonutils
 from nova import test
 from nova import utils
 
@@ -269,6 +271,15 @@ def _get_instance_nw_info(self, number):
                                           self.instance['uuid'],
                                           mox.IgnoreArg())
         port_data = number == 1 and self.port_data1 or self.port_data2
+        self.mox.StubOutWithMock(conductor_api.API,
+                                 'instance_get_by_uuid')
+        net_info_cache = []
+        for port in port_data:
+            net_info_cache.append({"network": {"id": port['network_id']}})
+        info_cache = {'info_cache': {'network_info':
+                                     jsonutils.dumps(net_info_cache)}}
+        api.conductor_api.instance_get_by_uuid(
+            mox.IgnoreArg(), mox.IgnoreArg()).AndReturn(info_cache)
         self.moxed_client.list_ports(
             tenant_id=self.instance['project_id'],
             device_id=self.instance['uuid']).AndReturn(
@@ -368,6 +379,16 @@ def test_get_instance_nw_info_without_subnet(self):
         quantumv2.get_client(mox.IgnoreArg(),
                              admin=True).MultipleTimes().AndReturn(
             self.moxed_client)
+        self.mox.StubOutWithMock(conductor_api.API,
+                                 'instance_get_by_uuid')
+        net_info_cache = []
+        for port in self.port_data3:
+            net_info_cache.append({"network": {"id": port['network_id']}})
+        info_cache = {'info_cache': {'network_info':
+                                     jsonutils.dumps(net_info_cache)}}
+
+        api.conductor_api.instance_get_by_uuid(
+            mox.IgnoreArg(), mox.IgnoreArg()).AndReturn(info_cache)
         self.mox.ReplayAll()
 
         nw_inf = api.get_instance_nw_info(self.context,
@@ -730,7 +751,17 @@ def test_deallocate_for_instance_2(self):
     def _test_deallocate_port_for_instance(self, number):
         port_data = number == 1 and self.port_data1 or self.port_data2
         self.moxed_client.delete_port(port_data[0]['id'])
+        self.mox.StubOutWithMock(conductor_api.API,
+                                 'instance_get_by_uuid')
+        net_info_cache = []
+        for port in port_data:
+            net_info_cache.append({"network": {"id": port['network_id']}})
+        info_cache = {'info_cache': {'network_info':
+                                     jsonutils.dumps(net_info_cache)}}
 
+        api = quantumapi.API()
+        api.conductor_api.instance_get_by_uuid(
+            mox.IgnoreArg(), mox.IgnoreArg()).AndReturn(info_cache)
         nets = [port_data[0]['network_id']]
         quantumv2.get_client(mox.IgnoreArg(), admin=True).AndReturn(
             self.moxed_client)
@@ -758,7 +789,6 @@ def _test_deallocate_port_for_instance(self, number):
 
         self.mox.ReplayAll()
 
-        api = quantumapi.API()
         nwinfo = api.deallocate_port_for_instance(self.context, self.instance,
                                                   port_data[0]['id'])
         self.assertEqual(len(nwinfo), len(port_data[1:]))