Merge "[OVN] Handle OVN agents when "Chassis" register is deleted"

neutron/plugins/ml2/drivers/ovn/agent/neutron_agent.py

@@ -23,6 +23,12 @@ from neutron.common.ovn import utils as ovn_utils
 from neutron.common import utils
 
 
+class DeletedChassis(object):
+    external_ids = {}
+    hostname = '("Chassis" register deleted)'
+    name = '("Chassis" register deleted)'
+
+
 class NeutronAgent(abc.ABC):
     types = {}
 
@@ -45,9 +51,12 @@ class NeutronAgent(abc.ABC):
     def chassis_from_private(chassis_private):
         try:
             return chassis_private.chassis[0]
-        except (AttributeError, IndexError):
+        except AttributeError:
             # No Chassis_Private support, just use Chassis
             return chassis_private
+        except IndexError:
+            # Chassis register has been deleted but not Chassis_Private.
+            return DeletedChassis
 
     @property
     def chassis(self):

neutron/tests/functional/plugins/ml2/drivers/ovn/mech_driver/test_mech_driver.py

@@ -997,9 +997,9 @@ class AgentWaitEvent(event.WaitEvent):
 
     ONETIME = False
 
-    def __init__(self, driver, chassis_names):
+    def __init__(self, driver, chassis_names, events=None):
         table = driver.agent_chassis_table
-        events = (self.ROW_CREATE,)
+        events = events or (self.ROW_CREATE,)
         self.chassis_names = chassis_names
         super().__init__(events, table, None)
         self.event_name = "AgentWaitEvent"
@@ -1059,11 +1059,41 @@ class TestAgentApi(base.TestOVNFunctionalBase):
             self.context, filters={'host': self.host})]
         self.assertCountEqual(list(self.agent_types.values()), agent_ids)
 
+        # "ovn-controller" ends without deleting "Chassis" and
+        # "Chassis_Private" registers. If "Chassis" register is deleted,
+        # then Chassis_Private.chassis = []; both metadata and controller
+        # agents will still be present in the agent list.
+        agent_event = AgentWaitEvent(self.mech_driver, [self.chassis],
+                                     events=(event.RowEvent.ROW_UPDATE,))
+        self.sb_api.idl.notify_handler.watch_event(agent_event)
+        self.sb_api.chassis_del(self.chassis).execute(check_error=True)
+        self.assertTrue(agent_event.wait())
+        agent_ids = [a['id'] for a in self.plugin.get_agents(
+            self.context, filters={'host': self.host})]
+        self.assertCountEqual(list(self.agent_types.values()), agent_ids)
+
     def test_agent_delete(self):
-        for agent_id in self.agent_types.values():
-            self.plugin.delete_agent(self.context, agent_id)
-            self.assertRaises(agent_exc.AgentNotFound, self.plugin.get_agent,
-                              self.context, agent_id)
+        # Non OVN agent deletion.
+        agent_id = self.agent_types[self.TEST_AGENT]
+        self.plugin.delete_agent(self.context, agent_id)
+        self.assertRaises(agent_exc.AgentNotFound, self.plugin.get_agent,
+                          self.context, agent_id)
+
+        # OVN controller agent deletion, that triggers the "Chassis" register
+        # deletion. The "Chassis" register deletion triggers the host OVN
+        # agents deletion, both controller and metadata if present.
+        controller_id = self.agent_types[ovn_const.OVN_CONTROLLER_AGENT]
+        metadata_id = self.agent_types[ovn_const.OVN_METADATA_AGENT]
+        self.plugin.delete_agent(self.context, controller_id)
+        self.assertRaises(agent_exc.AgentNotFound, self.plugin.get_agent,
+                          self.context, controller_id)
+        self.assertEqual(
+            metadata_id,
+            self.plugin.get_agent(self.context, metadata_id)['id'])
+
+        self.plugin.delete_agent(self.context, metadata_id)
+        self.assertRaises(agent_exc.AgentNotFound, self.plugin.get_agent,
+                          self.context, metadata_id)
 
 
 class ConnectionInactivityProbeSetEvent(event.WaitEvent):