[OVN] Add the default condition check in `PortBindingChassisEvent`

The event ``PortBindingChassisEvent`` should be executed only if the
initialization condition "type=ovn_const.OVN_CHASSIS_REDIRECT" is met.

This condition was skipped since [1], where the ``match_fn`` was
overriden.

[1]https://review.opendev.org/q/I3b7c5d73d2b0d20fb06527ade30af8939b249d75

Closes-Bug: #2037717
Change-Id: I01fa481456c0a675b5857d9796b8323493e4fbc1

neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/ovsdb_monitor.py

@@ -426,11 +426,13 @@ class PortBindingChassisEvent(row_event.RowEvent):
         self.l3_plugin = directory.get_plugin(constants.L3)
         table = 'Port_Binding'
         events = (self.ROW_UPDATE,)
-        super(PortBindingChassisEvent, self).__init__(
-            events, table, (('type', '=', ovn_const.OVN_CHASSIS_REDIRECT),))
+        super().__init__(events, table, None)
         self.event_name = 'PortBindingChassisEvent'
 
     def match_fn(self, event, row, old):
+        if row.type != ovn_const.OVN_CHASSIS_REDIRECT:
+            return False
+
         if len(old._data) == 1 and 'external_ids' in old._data:
             # NOTE: since [1], the NB logical_router_port.external_ids are
             # copied into the SB port_binding.external_ids. If only the

neutron/tests/functional/plugins/ml2/drivers/ovn/mech_driver/ovsdb/test_ovsdb_monitor.py

@@ -673,3 +673,45 @@ class TestOvnIdlConnections(base.TestOVNFunctionalBase):
                 **kwargs)
             self.assertEqual(set(idlutils.parse_connection(conns)),
                              set(idl._session.remotes))
+
+
+class TestPortBindingChassisEvent(base.TestOVNFunctionalBase,
+                                  test_l3.L3NatTestCaseMixin):
+
+    def setUp(self, **kwargs):
+        super().setUp(**kwargs)
+        self.chassis = self.add_fake_chassis('ovs-host1')
+        self.l3_plugin = directory.get_plugin(plugin_constants.L3)
+        kwargs = {'arg_list': (external_net.EXTERNAL,),
+                  external_net.EXTERNAL: True}
+        self.net = self._make_network(
+            self.fmt, 'ext_net', True, as_admin=True, **kwargs)
+        self._make_subnet(self.fmt, self.net, '20.0.10.1', '20.0.10.0/24')
+        port_res = self._create_port(self.fmt, self.net['network']['id'])
+        self.port = self.deserialize(self.fmt, port_res)['port']
+
+        self.ext_api = test_extensions.setup_extensions_middleware(
+            test_l3.L3TestExtensionManager())
+        self.pb_event_match = mock.patch.object(
+            self.sb_api.idl._portbinding_event, 'match_fn').start()
+
+    def _check_pb_type(self, _type):
+        def check_pb_type(_type):
+            if len(self.pb_event_match.call_args_list) < 1:
+                return False
+
+            pb_row = self.pb_event_match.call_args_list[0].args[1]
+            return _type == pb_row.type
+
+        n_utils.wait_until_true(lambda: check_pb_type(_type), timeout=5)
+
+    def test_pb_type_patch(self):
+        router = self._make_router(self.fmt, self._tenant_id)
+        self._add_external_gateway_to_router(router['router']['id'],
+                                             self.net['network']['id'])
+        self._check_pb_type('patch')
+
+    def test_pb_type_empty(self):
+        self.sb_api.lsp_bind(self.port['id'], self.chassis,
+                             may_exist=True).execute(check_error=True)
+        self._check_pb_type('')