Modify logic of l3-agent to be notified

Although no DVR router is hosted on controller node,
neutron-server notifies l3-agent on compute node.
As a result, the following bug happen when VM migrate or resize.
　1) L3-agent on compute node output error logs
     when VM connect no DVR and HA router.
　2) Unused namespace is appeared on compute node
     when VM connect no DVR and no HA router.
So, I modify logic of l3-agent to be notified
after migrating or resizing.

Change-Id: I53955b885f53d4ee15377a08627c2c25cb1b7041
Closes-Bug: #1775310

neutron/db/l3_dvrscheduler_db.py

@@ -453,8 +453,13 @@ def _notify_l3_agent_port_update(resource, event, trigger, **kwargs):
             fips = l3plugin._get_floatingips_by_port_id(
                 context, port_id=original_port['id'])
             fip = fips[0] if fips else None
-            if fip and not (removed_routers and
+            removed_router_ids = [
-                            fip['router_id'] in removed_routers):
+                info['router_id'] for info in removed_routers
+            ]
+            if (fip and
+                l3plugin.is_distributed_router(fip['router_id']) and
+                not (removed_routers and
+                     fip['router_id'] in removed_router_ids)):
                 l3plugin.l3_rpc_notifier.routers_updated_on_host(
                     context, [fip['router_id']],
                     original_port[portbindings.HOST_ID])

neutron/tests/unit/scheduler/test_l3_agent_scheduler.py

@@ -1036,9 +1036,34 @@ class L3DvrSchedulerTestCase(L3SchedulerBaseMixin,
         fip = {'router_id': 'router_id'}
         self._test__notify_l3_agent_port_binding_change(None, fip)
 
+    def test__notify_l3_agent_port_binding_change_fip_dvr(self):
+        fip = {'router_id': 'router_id'}
+        is_distributed = True
+        self._test__notify_l3_agent_port_binding_change(None,
+                                                        fip, is_distributed)
+
+    def test__notify_l3_agent_port_binding_change_fip_dvr_rmrt(self):
+        fip = {'router_id': 'router_id'}
+        router_to_remove = [{'agent_id': 'foo_agent',
+                             'router_id': 'foo_id',
+                             'host': 'vm-host1'}]
+        is_distributed = True
+        self._test__notify_l3_agent_port_binding_change(router_to_remove,
+                                                        fip, is_distributed)
+
+    def test__notify_l3_agent_port_binding_change_fip_dvr_on_rmrt(self):
+        fip = {'router_id': 'foo_id'}
+        router_to_remove = [{'agent_id': 'foo_agent',
+                             'router_id': 'foo_id',
+                             'host': 'vm-host1'}]
+        is_distributed = True
+        self._test__notify_l3_agent_port_binding_change(router_to_remove,
+                                                        fip, is_distributed)
+
     def _test__notify_l3_agent_port_binding_change(self,
                                                    routers_to_remove=None,
-                                                   fip=None):
+                                                   fip=None,
+                                                   is_distributed=False):
         source_host = 'vm-host1'
         kwargs = {
             'context': self.adminContext,
@@ -1055,9 +1080,12 @@ class L3DvrSchedulerTestCase(L3SchedulerBaseMixin,
         l3plugin = mock.Mock()
         directory.add_plugin(plugin_constants.L3, l3plugin)
         with mock.patch.object(l3plugin, 'get_dvr_routers_to_remove',
-                               return_value=routers_to_remove),\
+                               return_value=routers_to_remove
+                               if routers_to_remove else []),\
                 mock.patch.object(l3plugin, '_get_floatingips_by_port_id',
-                                  return_value=[fip] if fip else []):
+                                  return_value=[fip] if fip else []),\
+                mock.patch.object(l3plugin, 'is_distributed_router',
+                                  return_value=is_distributed):
             l3_dvrscheduler_db._notify_l3_agent_port_update(
                 'port', 'after_update', mock.ANY, **kwargs)
             if routers_to_remove:
@@ -1066,7 +1094,8 @@ class L3DvrSchedulerTestCase(L3SchedulerBaseMixin,
                 self.assertEqual(
                     1,
                     l3plugin.delete_arp_entry_for_dvr_service_port.call_count)
-            if fip and not routers_to_remove:
+            if fip and is_distributed and not (routers_to_remove and
+                fip['router_id'] is routers_to_remove[0]['router_id']):
                 (l3plugin.l3_rpc_notifier.routers_updated_on_host.
                  assert_called_once_with(mock.ANY, ['router_id'], source_host))
             self.assertEqual(