Use publish for AGENT AFTER_CREATE/AFTER_UPDATE

This patch switches callbacks over to the payload object style events
for AGENT AFTER_CREATE and AFTER_UPDATE based notifications. To do
so a DBEventPayload object is used with the publish() method to
pass along the API related data.

Change-Id: Ibefa495be41c91957c2e8d797130e569bccc3765

neutron/db/agents_db.py

@@ -13,6 +13,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import copy
 import datetime
 
 from eventlet import greenthread
@@ -390,6 +391,7 @@ class AgentDbMixin(ext_agent.AgentPluginBase, AgentAvailabilityZoneMixin):
             try:
                 agent = self._get_agent_by_type_and_host(
                     context, agent_state['agent_type'], agent_state['host'])
+                agent_state_orig = copy.deepcopy(agent_state)
                 if not agent.is_active:
                     status = agent_consts.AGENT_REVIVED
                     if 'resource_versions' not in agent_state:
@@ -408,6 +410,7 @@ class AgentDbMixin(ext_agent.AgentPluginBase, AgentAvailabilityZoneMixin):
                 agent.update()
                 event_type = events.AFTER_UPDATE
             except agent_exc.AgentNotFoundByTypeHost:
+                agent_state_orig = None
                 greenthread.sleep(0)
                 res['created_at'] = current_time
                 res['started_at'] = current_time
@@ -423,9 +426,17 @@ class AgentDbMixin(ext_agent.AgentPluginBase, AgentAvailabilityZoneMixin):
 
         agent_state['agent_status'] = status
         agent_state['admin_state_up'] = agent.admin_state_up
-        registry.notify(resources.AGENT, event_type, self, context=context,
-                        host=agent_state['host'], plugin=self,
-                        agent=agent_state, status=status)
+        registry.publish(resources.AGENT, event_type, self,
+                         payload=events.DBEventPayload(
+                             context=context, metadata={
+                                 'host': agent_state['host'],
+                                 'plugin': self,
+                                 'status': status
+                             },
+                             states=(agent_state_orig, ),
+                             desired_state=agent_state,
+                             resource_id=agent.id
+                         ))
         return status, agent_state
 
     def _get_agents_considered_for_versions(self):

neutron/plugins/ml2/plugin.py

@@ -341,10 +341,10 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
 
     @registry.receives(resources.AGENT, [events.AFTER_UPDATE])
     def _retry_binding_revived_agents(self, resource, event, trigger,
-                                      **kwargs):
-        context = kwargs['context']
-        host = kwargs['host']
-        agent = kwargs.get('agent', {})
+                                      payload=None):
+        context = payload.context
+        host = payload.metadata.get('host')
+        agent = payload.desired_state
         agent_status = agent.get('agent_status')
 
         agent_type = agent.get('agent_type')

neutron/services/segments/db.py

@@ -255,8 +255,12 @@ def map_segment_to_hosts(context, segment_id, hosts):
 
 
 def _update_segment_host_mapping_for_agent(resource, event, trigger,
-                                           context, host, plugin, agent,
-                                           status):
+                                           payload=None):
+    plugin = payload.metadata.get('plugin')
+    agent = payload.desired_state
+    host = payload.metadata.get('host')
+    context = payload.context
+
     check_segment_for_agent = getattr(plugin, 'check_segment_for_agent', None)
     if not check_segment_for_agent:
         return

neutron/tests/unit/db/test_agents_db.py

@@ -24,6 +24,7 @@ from neutron_lib import exceptions as n_exc
 from oslo_config import cfg
 from oslo_db import exception as exc
 from oslo_utils import timeutils
+from oslo_utils import uuidutils
 import testscenarios
 
 from neutron.db import agents_db
@@ -160,11 +161,16 @@ class TestAgentsDbMixin(TestAgentsDbBase):
             'neutron.objects.base.NeutronDbObject.modify_fields_from_db'
         ).start()
 
+        counter = {'value': 0}
+
+        def create_obj_side_effect(obj_cls, context, values, populate_id=True):
+            if counter['value'] < 1:
+                counter['value'] += 1
+                raise exc.DBDuplicateEntry()
+            obj_cls.id = uuidutils.generate_uuid()
+
         with mock.patch('neutron.objects.db.api.create_object') as add_mock:
-            add_mock.side_effect = [
-                exc.DBDuplicateEntry(),
-                mock.Mock()
-            ]
+            add_mock.side_effect = create_obj_side_effect
             self.plugin.create_or_update_agent(self.context, self.agent_status)
 
             self.assertEqual(add_mock.call_count, 2,

neutron/tests/unit/plugins/ml2/test_plugin.py

@@ -746,7 +746,11 @@ class TestMl2RevivedAgentsBindPorts(Ml2PluginV2TestCase):
 
             plugin._retry_binding_revived_agents(
                 resources.AGENT, event, plugin,
-                **{'context': context, 'host': host, 'agent': agent})
+                events.DBEventPayload(
+                    context=context, metadata={'host': host}, states=(agent,),
+                    desired_state=agent
+                )
+            )
 
             if (agent_status == agent_consts.AGENT_ALIVE or
                     not admin_state_up or

releasenotes/notes/use-callback-payload-for-AGENT-AFTER_CREATE-and-AFTER_UPDATE-events-839d8dcb0ac5ff26.yaml

@@ -0,0 +1,5 @@
+---
+other:
+  - |
+    Use ``publish`` for ``AGENT's`` ``AFTER_CREATE`` and ``AFTER_UPDATE`` events
+    with ``DBEventPayload`` instead of the deprecated notify callback.