remove unused updated_at parameter for AgentCache.update

we cannot find this parameter passed in anywhere except for some unit
tests. currently we have used nb_cfg_timestamp[1] as agent updated
time. there are no other scenarios for this parameter. this patch
remove it and update some unit test.

[1] https://review.opendev.org/c/openstack/neutron/+/802834

Closes-bug: #1978035

Change-Id: Ic964b7ddc70988bb1a822b07be6a1be4d197287e
(cherry picked from commit 7dbc613)

Author: zhouhenglc

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

@@ -38,27 +38,26 @@ def __init_subclass__(cls):
         # Register the subclasses to be looked up by their type
         NeutronAgent.types[cls.agent_type] = cls
 
-    def __init__(self, chassis_private, driver, updated_at=None):
+    def __init__(self, chassis_private, driver):
         self.driver = driver
         self.set_down = False
-        self.update(chassis_private, updated_at)
+        self.update(chassis_private)
 
-    def update(self, chassis_private, updated_at=None, clear_down=False):
+    def update(self, chassis_private, clear_down=False):
         self.chassis_private = chassis_private
-        if not updated_at:
-            # When use the Chassis_Private table for agents health check,
-            # chassis_private has attribute nb_cfg_timestamp.
-            # nb_cfg_timestamp: the timestamp when ovn-controller finishes
-            # processing the change corresponding to nb_cfg(
-            # https://www.ovn.org/support/dist-docs/ovn-sb.5.html).
-            # it can better reflect the status of chassis.
-            # nb_cfg_timestamp is milliseconds, need to convert to datetime.
-            if hasattr(chassis_private, 'nb_cfg_timestamp'):
-                updated_at = datetime.datetime.fromtimestamp(
-                    chassis_private.nb_cfg_timestamp / 1000,
-                    datetime.timezone.utc)
-            else:
-                updated_at = timeutils.utcnow(with_timezone=True)
+        # When use the Chassis_Private table for agents health check,
+        # chassis_private has attribute nb_cfg_timestamp.
+        # nb_cfg_timestamp: the timestamp when ovn-controller finishes
+        # processing the change corresponding to nb_cfg(
+        # https://www.ovn.org/support/dist-docs/ovn-sb.5.html).
+        # it can better reflect the status of chassis.
+        # nb_cfg_timestamp is milliseconds, need to convert to datetime.
+        if hasattr(chassis_private, 'nb_cfg_timestamp'):
+            updated_at = datetime.datetime.fromtimestamp(
+                chassis_private.nb_cfg_timestamp / 1000,
+                datetime.timezone.utc)
+        else:
+            updated_at = timeutils.utcnow(with_timezone=True)
         self.updated_at = updated_at
         if clear_down:
             self.set_down = False
@@ -112,8 +111,8 @@ def alive(self):
         return False
 
     @classmethod
-    def from_type(cls, _type, chassis_private, driver, updated_at=None):
-        return cls.types[_type](chassis_private, driver, updated_at)
+    def from_type(cls, _type, chassis_private, driver):
+        return cls.types[_type](chassis_private, driver)
 
     @property
     @abc.abstractmethod
@@ -141,7 +140,7 @@ class ControllerAgent(NeutronAgent):
     binary = 'ovn-controller'
 
     @staticmethod  # it is by default, but this makes pep8 happy
-    def __new__(cls, chassis_private, driver, updated_at=None):
+    def __new__(cls, chassis_private, driver):
         external_ids = cls.chassis_from_private(chassis_private).external_ids
         if ('enable-chassis-as-gw' in
                 external_ids.get('ovn-cms-options', [])):
@@ -165,8 +164,8 @@ def description(self):
         return self.chassis_private.external_ids.get(
             ovn_const.OVN_AGENT_DESC_KEY, '')
 
-    def update(self, chassis_private, updated_at=None, clear_down=False):
-        super().update(chassis_private, updated_at, clear_down)
+    def update(self, chassis_private, clear_down=False):
+        super().update(chassis_private, clear_down)
         external_ids = self.chassis_from_private(chassis_private).external_ids
         if 'enable-chassis-as-gw' in external_ids.get('ovn-cms-options', []):
             self.__class__ = ControllerGatewayAgent
@@ -175,8 +174,8 @@ def update(self, chassis_private, updated_at=None, clear_down=False):
 class ControllerGatewayAgent(ControllerAgent):
     agent_type = ovn_const.OVN_CONTROLLER_GW_AGENT
 
-    def update(self, chassis_private, updated_at=None, clear_down=False):
-        super().update(chassis_private, updated_at, clear_down)
+    def update(self, chassis_private, clear_down=False):
+        super().update(chassis_private, clear_down)
         external_ids = self.chassis_from_private(chassis_private).external_ids
         if ('enable-chassis-as-gw' not in
                 external_ids.get('ovn-cms-options', [])):
@@ -238,14 +237,13 @@ def __iter__(self):
     def __getitem__(self, key):
         return self.agents[key]
 
-    def update(self, agent_type, row, updated_at=None, clear_down=False):
+    def update(self, agent_type, row, clear_down=False):
         cls = NeutronAgent.types[agent_type]
         try:
             agent = self.agents[cls.id_from_chassis_private(row)]
-            agent.update(row, updated_at=updated_at, clear_down=clear_down)
+            agent.update(row, clear_down=clear_down)
         except KeyError:
-            agent = NeutronAgent.from_type(agent_type, row, self.driver,
-                                           updated_at=updated_at)
+            agent = NeutronAgent.from_type(agent_type, row, self.driver)
             self.agents[agent.agent_id] = agent
         return agent
 

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

@@ -100,37 +100,25 @@ def _add_chassis(self, nb_cfg, name=None):
         chassis_private.name = name if name else str(uuid.uuid4())
         return chassis_private
 
-    def _add_chassis_agent(self, nb_cfg, agent_type, chassis_private=None,
-                           updated_at=None):
+    def _add_chassis_agent(self, nb_cfg, agent_type, chassis_private=None):
         chassis_private = chassis_private or self._add_chassis(nb_cfg)
         if hasattr(chassis_private, 'nb_cfg_timestamp') and isinstance(
                 chassis_private.nb_cfg_timestamp, mock.Mock):
             del chassis_private.nb_cfg_timestamp
         chassis_private.external_ids = {}
-        if updated_at:
-            chassis_private.external_ids = {
-                ovn_const.OVN_LIVENESS_CHECK_EXT_ID_KEY:
-                    datetime.datetime.isoformat(updated_at)}
         if agent_type == ovn_const.OVN_METADATA_AGENT:
             chassis_private.external_ids.update({
                 ovn_const.OVN_AGENT_METADATA_SB_CFG_KEY: nb_cfg,
                 ovn_const.OVN_AGENT_METADATA_ID_KEY: str(uuid.uuid4())})
         chassis_private.chassis = [chassis_private]
-        return neutron_agent.AgentCache().update(agent_type, chassis_private,
-                                                 updated_at)
+        return neutron_agent.AgentCache().update(agent_type, chassis_private)
 
-    def _add_agent(self, name, alive=True):
+    def _add_agent(self, name, nb_cfg_offset=0):
         nb_cfg = 5
-        now = timeutils.utcnow(with_timezone=True)
-        if not alive:
-            updated_at = now - datetime.timedelta(cfg.CONF.agent_down_time + 1)
-            self.mech_driver.nb_ovn.nb_global.nb_cfg = nb_cfg
-        else:
-            updated_at = now
-            self.mech_driver.nb_ovn.nb_global.nb_cfg = nb_cfg + 2
+        self.mech_driver.nb_ovn.nb_global.nb_cfg = nb_cfg + nb_cfg_offset
         chassis = self._add_chassis(nb_cfg, name=name)
         return self._add_chassis_agent(
-            nb_cfg, ovn_const.OVN_CONTROLLER_AGENT, chassis, updated_at)
+            nb_cfg, ovn_const.OVN_CONTROLLER_AGENT, chassis)
 
 
 class TestOVNMechanismDriverBase(MechDriverSetupBase,
@@ -1252,9 +1240,13 @@ def test_bind_port_physnet_not_found(self):
         self._test_bind_port_failed(fake_segments)
 
     def test_bind_port_host_not_alive(self):
-        agent = self._add_agent('agent_no_alive', False)
-        neutron_agent.AgentCache().get_agents.return_value = [agent]
-        self._test_bind_port_failed([])
+        agent = self._add_agent('agent_no_alive', 2)
+        now = timeutils.utcnow(with_timezone=True)
+        fake_now = now + datetime.timedelta(cfg.CONF.agent_down_time + 1)
+        with mock.patch.object(timeutils, 'utcnow') as get_now:
+            get_now.return_value = fake_now
+            neutron_agent.AgentCache().get_agents.return_value = [agent]
+            self._test_bind_port_failed([])
 
     def _test_bind_port(self, fake_segments):
         fake_port = fakes.FakePort.create_one_port().info()
@@ -2239,12 +2231,14 @@ def test_agent_alive_true_one_diff(self):
         for agent_type in (ovn_const.OVN_CONTROLLER_AGENT,
                            ovn_const.OVN_METADATA_AGENT):
             self.mech_driver.nb_ovn.nb_global.nb_cfg = nb_cfg + 1
-            now = timeutils.utcnow()
-            updated_at = now - datetime.timedelta(cfg.CONF.agent_down_time + 1)
             agent = self._add_chassis_agent(nb_cfg, agent_type,
-                                            chassis_private, updated_at)
-            self.assertTrue(agent.alive, "Agent of type %s alive=%s" %
-                                         (agent.agent_type, agent.alive))
+                                            chassis_private)
+            now = timeutils.utcnow()
+            fake_now = now + datetime.timedelta(cfg.CONF.agent_down_time + 1)
+            with mock.patch.object(timeutils, 'utcnow') as get_now:
+                get_now.return_value = fake_now
+                self.assertTrue(agent.alive, "Agent of type %s alive=%s" %
+                                             (agent.agent_type, agent.alive))
 
     def test_agent_alive_not_timed_out(self):
         nb_cfg = 3
@@ -2264,11 +2258,13 @@ def test_agent_alive_timed_out(self):
                            ovn_const.OVN_METADATA_AGENT):
             self.mech_driver.nb_ovn.nb_global.nb_cfg = nb_cfg + 2
             now = timeutils.utcnow(with_timezone=True)
-            updated_at = now - datetime.timedelta(cfg.CONF.agent_down_time + 1)
             agent = self._add_chassis_agent(nb_cfg, agent_type,
-                                            chassis_private, updated_at)
-            self.assertFalse(agent.alive, "Agent of type %s alive=%s" %
-                             (agent.agent_type, agent.alive))
+                                            chassis_private)
+            fake_now = now + datetime.timedelta(cfg.CONF.agent_down_time + 1)
+            with mock.patch.object(timeutils, 'utcnow') as get_now:
+                get_now.return_value = fake_now
+                self.assertFalse(agent.alive, "Agent of type %s alive=%s" %
+                                 (agent.agent_type, agent.alive))
 
     def test_agent_with_nb_cfg_timestamp_timeout(self):
         nb_cfg = 3