From 32bfc3edeca935fc9c16b3019aa0af3091cd19e7 Mon Sep 17 00:00:00 2001
From: Swaminathan Vasudevan <SVasudevan@suse.com>
Date: Sun, 1 Oct 2017 23:27:29 -0700
Subject: [PATCH] DVR: Cleanup ml2 dvr portbindings on migration

When a DVR router is migrated from distributed to
centralized, we are unbinding the router from the
agents, but the ml2 distributed portbindings for
the router port still remains intact.

This patch will fix the issue by deleting the
binding entry for multiple hosts.

Closes-Bug: #1718345
Change-Id: If139790eb336ff13b07b094151946af30322ad3e
---
 neutron/db/l3_dvr_db.py                 | 13 +++++++++++++
 neutron/plugins/ml2/plugin.py           |  7 +++++++
 neutron/tests/unit/db/test_l3_dvr_db.py | 26 +++++++++++++++++++++++++
 3 files changed, 46 insertions(+)

diff --git a/neutron/db/l3_dvr_db.py b/neutron/db/l3_dvr_db.py
index cd392ba5a7c..e563c5732cf 100644
--- a/neutron/db/l3_dvr_db.py
+++ b/neutron/db/l3_dvr_db.py
@@ -185,6 +185,19 @@ class DVRResourceOperationHandler(object):
             payload.context, payload.desired_state,
             'distributed', migrating_to_distributed)
 
+    @registry.receives(resources.ROUTER, [events.AFTER_UPDATE],
+                       priority_group.PRIORITY_ROUTER_EXTENDED_ATTRIBUTE)
+    def _delete_distributed_port_bindings_after_change(self, resource, event,
+                                                       trigger, context,
+                                                       router_id, router,
+                                                       request_attrs,
+                                                       router_db, **kwargs):
+        old_router = kwargs['old_router']
+        if (old_router and old_router['distributed'] and not
+                router['distributed']):
+            self._core_plugin.delete_distributed_port_bindings_by_router_id(
+                context.elevated(), router_db['id'])
+
     @registry.receives(resources.ROUTER, [events.AFTER_UPDATE],
                        priority_group.PRIORITY_ROUTER_EXTENDED_ATTRIBUTE)
     def _delete_snat_interfaces_after_change(self, resource, event, trigger,
diff --git a/neutron/plugins/ml2/plugin.py b/neutron/plugins/ml2/plugin.py
index 9c97af4a02d..24a3d1a34bb 100644
--- a/neutron/plugins/ml2/plugin.py
+++ b/neutron/plugins/ml2/plugin.py
@@ -1812,6 +1812,13 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
         # merge into session to reflect changes
         binding.persist_state_to_session(plugin_context.session)
 
+    def delete_distributed_port_bindings_by_router_id(self, context,
+                                                      router_id):
+        for binding in (context.session.query(models.DistributedPortBinding).
+                filter_by(router_id=router_id)):
+            db.clear_binding_levels(context, binding.port_id, binding.host)
+            context.session.delete(binding)
+
     @utils.transaction_guard
     @db_api.retry_if_session_inactive()
     def update_distributed_port_binding(self, context, id, port):
diff --git a/neutron/tests/unit/db/test_l3_dvr_db.py b/neutron/tests/unit/db/test_l3_dvr_db.py
index 4441c886eae..37ad3e6da85 100644
--- a/neutron/tests/unit/db/test_l3_dvr_db.py
+++ b/neutron/tests/unit/db/test_l3_dvr_db.py
@@ -224,6 +224,32 @@ class L3DvrTestCase(test_db_base_plugin_v2.NeutronDbPluginV2TestCase):
         self.assertEqual(1,
                          self.mixin._migrate_router_ports.call_count)
 
+    def test_update_router_db_distributed_to_centralized(self):
+        router = {'name': 'foo_router', 'admin_state_up': True,
+                  'distributed': True}
+        agent = {'id': _uuid(), 'host': 'xyz'}
+        router_db = self._create_router(router)
+        router_id = router_db['id']
+        self.assertTrue(router_db.extra_attributes.distributed)
+        self.mixin._get_router = mock.Mock(return_value=router_db)
+        self.mixin._validate_router_migration = mock.Mock()
+        self.mixin._migrate_router_ports = mock.Mock()
+        self.mixin._core_plugin.\
+            delete_distributed_port_bindings_by_router_id = mock.Mock()
+        self.mixin.list_l3_agents_hosting_router = mock.Mock(
+            return_value={'agents': [agent]})
+        self.mixin._unbind_router = mock.Mock()
+        updated_router = self.mixin.update_router(self.ctx, router_id,
+            {'router': {'distributed': False}})
+        # Assert that the DB value has changed
+        self.assertFalse(updated_router['distributed'])
+        self.assertEqual(1,
+                         self.mixin._migrate_router_ports.call_count)
+        self.assertEqual(
+            1,
+            self.mixin._core_plugin.
+            delete_distributed_port_bindings_by_router_id.call_count)
+
     def _test_get_device_owner(self, is_distributed=False,
                                expected=const.DEVICE_OWNER_ROUTER_INTF,
                                pass_router_id=True):