[OVN] Remove OVN_GATEWAY_INVALID_CHASSIS artifact

This artifact is no longer used in the "Logical_Router" registers (in
the "options" field) to mark this "Logical_Router" as unhosted. A
"Logical_Router" is considered as unhosted if the gateway
"Logical_Router_Ports" have no "chassis" set.

This artifact is also used to create a "Gateway_Chassis" register
pointing to a inexisting invalid chassis called
"neutron-ovn-invalid-chassis". Any "Logical_Router_Port" not bound
to a chassis will have no value in "gateway_chassis" (NOTE1).

NOTE1: this is valid now with the current two OVN L3 schedulers that
use "gateway_chassis" to schedule the "Logical_Router_Port" of a
router. In a future, we can consider using "ha_chassis_group" for
scheduling.

Partial-Bug: #2052821
Related-Bug: #2019217
Change-Id: I12717936fe2bc188545309bacb8a260981f14c88

doc/source/admin/ovn/l3_scheduler.rst

@@ -26,10 +26,9 @@ The maximum number of ``Gateway_Chassis`` that can be assigned to a
 the highest priority a ``Gateway_Chassis`` will have is 5.
 
 If no gateway chassis are available during the ``Logical_Router_Port``
-scheduling, no ``Gateway_Chassis`` will be assigned and the value
-"neutron-ovn-invalid-chassis" will be set in the "options" column of the
-``Logical_Router`` register; that value will be used to detect an unhosted
-router gateway port.
+scheduling, no ``Gateway_Chassis`` will be assigned and no value will be set
+in the "options" column of the ``Logical_Router`` register; that will be used
+to detect an unhosted router gateway port.
 
 
 Types of schedulers
@@ -88,7 +87,7 @@ Both the ``OVNGatewayChanceScheduler`` and the
 ``OVNGatewayLeastLoadedScheduler`` schedulers have the Availability Zones (AZ)
 in consideration. If a router has any AZ defined, the schedulers will select
 only those chassis located in the AZs. If no chassis meets this condition, the
-``Logical_Router_Port`` will be assigned to the "neutron-ovn-invalid-chassis".
+``Logical_Router_Port`` won't be assigned to any chassis and won't be bound.
 
 Once the list of candidate ``Chassis`` (depending on the scheduler selected)
 is created, this list is reordered to prioritize these ``Chassis`` from

neutron/common/ovn/constants.py

@@ -109,12 +109,6 @@ ACL_ACTION_ALLOW_RELATED = 'allow-related'
 ACL_ACTION_ALLOW_STATELESS = 'allow-stateless'
 ACL_ACTION_ALLOW = 'allow'
 
-# When a OVN L3 gateway is created, it needs to be bound to a chassis. In
-# case a chassis is not found OVN_GATEWAY_INVALID_CHASSIS will be set in
-# the options column of the Logical Router. This value is used to detect
-# unhosted router gateways to schedule.
-OVN_GATEWAY_INVALID_CHASSIS = 'neutron-ovn-invalid-chassis'
-
 # NOTE(lucasagomes): These options were last synced from
 # https://github.com/ovn-org/ovn/blob/feb5d6e81d5a0290aa3618a229c860d01200422e/lib/ovn-l7.h
 #

neutron/common/ovn/utils.py

@@ -669,10 +669,7 @@ def is_gateway_chassis_invalid(chassis_name, gw_chassis,
     @type     chassis_with_azs: {}
     @return   Boolean
     """
-
-    if chassis_name == constants.OVN_GATEWAY_INVALID_CHASSIS:
-        return True
-    elif chassis_name not in chassis_physnets:
+    if chassis_name not in chassis_physnets:
         return True
     elif physnet and physnet not in chassis_physnets.get(chassis_name):
         return True

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

@@ -412,10 +412,9 @@ class ScheduleNewGatewayCommand(command.BaseCommand):
         chassis = self.scheduler.select(
             self.api, self.sb_api, self.g_name, candidates=candidates,
             target_lrouter=lrouter)
-
-        setattr(
-            lrouter_port,
-            *_add_gateway_chassis(self.api, txn, self.g_name, chassis))
+        if chassis:
+            setattr(lrouter_port,
+                    *_add_gateway_chassis(self.api, txn, self.g_name, chassis))
 
 
 class AddLRouterPortCommand(command.BaseCommand):

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

@@ -551,8 +551,16 @@ class OvsdbNbOvnIdl(nb_impl_idl.OvnNbApiIdlImpl, Backend):
 
     def get_unhosted_gateways(self, port_physnet_dict, chassis_with_physnets,
                               all_gw_chassis, chassis_with_azs):
+        """Return the GW LRPs with no chassis assigned
+
+        If the LRP belongs to a tunnelled network (physnet=None), it won't be
+        hosted to any chassis.
+        """
         unhosted_gateways = set()
         for port, physnet in port_physnet_dict.items():
+            if not physnet:
+                continue
+
             lrp_name = '%s%s' % (ovn_const.LRP_PREFIX, port)
             original_state = self.get_gateway_chassis_binding(lrp_name)
             az_hints = self.get_gateway_chassis_az_hints(lrp_name)

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

@@ -29,6 +29,7 @@ from neutron_lib.exceptions import l3 as l3_exc
 from oslo_config import cfg
 from oslo_log import log
 from oslo_serialization import jsonutils
+from oslo_utils import strutils
 from oslo_utils import timeutils
 from ovsdbapp.backend.ovs_idl import event as row_event
 
@@ -1204,6 +1205,29 @@ class DBInconsistenciesPeriodics(SchemaAwarePeriodicsBase):
 
         raise periodics.NeverAgain()
 
+    # TODO(ralonsoh): Remove this method in the C+2 cycle (next SLURP release)
+    @has_lock_periodic(spacing=600, run_immediately=True)
+    def remove_invalid_gateway_chassis_from_unbound_lrp(self):
+        """Removes all invalid 'Gateway_Chassis' from unbound LRPs"""
+        is_gw = ovn_const.OVN_ROUTER_IS_EXT_GW
+        lrp_list = []
+        for lr in self._nb_idl.lr_list().execute(check_error=True):
+            for lrp in self._nb_idl.lrp_list(lr.uuid).execute(
+                    check_error=True):
+                if (is_gw in lrp.external_ids and
+                        strutils.bool_from_string(lrp.external_ids[is_gw]) and
+                        lrp.gateway_chassis and
+                        lrp.gateway_chassis[0].chassis_name ==
+                        'neutron-ovn-invalid-chassis'):
+                    lrp_list.append(lrp)
+
+        with self._nb_idl.transaction(check_error=True) as txn:
+            for lrp in lrp_list:
+                txn.add(self._nb_idl.lrp_del_gateway_chassis(
+                    lrp.uuid, 'neutron-ovn-invalid-chassis'))
+
+        raise periodics.NeverAgain()
+
 
 class HashRingHealthCheckPeriodics(object):
 

neutron/scheduler/l3_ovn_scheduler.py

@@ -47,7 +47,7 @@ class OVNGatewayScheduler(object, metaclass=abc.ABCMeta):
                                 physnet, chassis_physnets,
                                 existing_chassis, az_hints, chassis_with_azs):
         chassis_list = copy.copy(existing_chassis)
-        for chassis_name in existing_chassis:
+        for chassis_name in existing_chassis or []:
             if utils.is_gateway_chassis_invalid(chassis_name, gw_chassis,
                                                 physnet, chassis_physnets,
                                                 az_hints, chassis_with_azs):
@@ -73,7 +73,7 @@ class OVNGatewayScheduler(object, metaclass=abc.ABCMeta):
         if not candidates:
             LOG.warning('Gateway %s was not scheduled on any chassis, no '
                         'candidates are available', gateway_name)
-            return [ovn_const.OVN_GATEWAY_INVALID_CHASSIS]
+            return
         chassis_count = min(
             ovn_const.MAX_GW_CHASSIS - len(existing_chassis),
             len(candidates)
@@ -97,8 +97,7 @@ class OVNGatewayScheduler(object, metaclass=abc.ABCMeta):
         azs = set()
 
         # Check if candidates list valid
-        if not candidates or (
-                candidates == [ovn_const.OVN_GATEWAY_INVALID_CHASSIS]):
+        if not candidates:
             return candidates
 
         chassis_with_azs = sb_idl.get_chassis_and_azs()

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

@@ -175,9 +175,9 @@ class _TestMaintenanceHelper(base.TestOVNFunctionalBase):
         res = req.get_response(self.api)
         return self.deserialize(self.fmt, res)['router']
 
-    def _update_router_name(self, net_id, new_name):
-        data = {'router': {'name': new_name}}
-        req = self.new_update_request('routers', data, net_id, self.fmt)
+    def _update_router(self, router_id, router_dict):
+        data = {'router': router_dict}
+        req = self.new_update_request('routers', data, router_id, self.fmt)
         res = req.get_response(self.api)
         return self.deserialize(self.fmt, res)['router']
 
@@ -591,8 +591,8 @@ class TestMaintenance(_TestMaintenanceHelper):
 
         new_obj_name = 'routertest_updated'
         with mock.patch.object(self._l3_ovn_client, 'update_router'):
-            new_neutron_obj = self._update_router_name(neutron_obj['id'],
-                                                       new_obj_name)
+            new_neutron_obj = self._update_router(neutron_obj['id'],
+                                                  {'name': new_obj_name})
 
         # Assert the revision numbers are out-of-sync
         ovn_obj = self._find_router_row_by_name(obj_name)
@@ -1190,6 +1190,36 @@ class TestMaintenance(_TestMaintenanceHelper):
         self.assertIn(router1['id'], pra_res_ids)
         self.assertIn(router2['id'], pra_res_ids)
 
+    def test_remove_invalid_gateway_chassis_from_unbound_lrp(self):
+        net1 = self._create_network(uuidutils.generate_uuid(), external=True)
+        subnet1 = self._create_subnet(uuidutils.generate_uuid(), net1['id'])
+        external_gateway_info = {
+            'enable_snat': True, 'network_id': net1['id'],
+            'external_fixed_ips': [{'ip_address': '10.0.0.2',
+                                    'subnet_id': subnet1['id']}]}
+        router = self._create_router(
+            uuidutils.generate_uuid(),
+            external_gateway_info=external_gateway_info)
+
+        # Manually add the LRP.gateway_chassis with name
+        # 'neutron-ovn-invalid-chassis'
+        lr = self.nb_api.lookup('Logical_Router', utils.ovn_name(router['id']))
+        lrp = lr.ports[0]
+        self.nb_api.lrp_set_gateway_chassis(
+            lrp.uuid, 'neutron-ovn-invalid-chassis').execute(check_error=True)
+        gc = self.nb_api.db_find_rows(
+            'Gateway_Chassis',
+            ('chassis_name', '=', 'neutron-ovn-invalid-chassis')).execute(
+            check_error=True)[0]
+
+        self.assertRaises(
+            periodics.NeverAgain,
+            self.maint.remove_invalid_gateway_chassis_from_unbound_lrp)
+        self.assertIsNone(self.nb_api.lookup('Gateway_Chassis', gc.uuid,
+                                             default=None))
+        lr = self.nb_api.lookup('Logical_Router', utils.ovn_name(router['id']))
+        self.assertEqual([], lr.ports[0].gateway_chassis)
+
 
 class TestLogMaintenance(_TestMaintenanceHelper,
                          test_log_driver.LogApiTestCaseBase):

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

@@ -20,6 +20,7 @@ import fixtures as og_fixtures
 from neutron_lib.api.definitions import allowedaddresspairs
 from neutron_lib.api.definitions import external_net
 from neutron_lib.api.definitions import portbindings
+from neutron_lib.api.definitions import provider_net
 from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from oslo_concurrency import processutils
@@ -517,8 +518,10 @@ class TestSBDbMonitor(base.TestOVNFunctionalBase, test_l3.L3NatTestCaseMixin):
 
     def setUp(self, **kwargs):
         super().setUp(**kwargs)
-        self.chassis = self.add_fake_chassis('ovs-host1',
-                                             enable_chassis_as_gw=True)
+        self.physnet = 'public'
+        self.chassis = self.add_fake_chassis(
+            'ovs-host1', physical_nets=[self.physnet],
+            enable_chassis_as_gw=True)
         self.l3_plugin = directory.get_plugin(plugin_constants.L3)
         ext_mgr = test_l3.L3TestExtensionManager()
         self.ext_api = test_extensions.setup_extensions_middleware(ext_mgr)
@@ -545,10 +548,12 @@ class TestSBDbMonitor(base.TestOVNFunctionalBase, test_l3.L3NatTestCaseMixin):
                 return True
             return lrp.external_ids == pb.external_ids
 
-        kwargs = {'arg_list': (external_net.EXTERNAL,),
-                  external_net.EXTERNAL: True}
+        arg_dict = {external_net.EXTERNAL: True,
+                    provider_net.NETWORK_TYPE: 'flat',
+                    provider_net.PHYSICAL_NETWORK: self.physnet}
         ext_net = self._make_network(self.fmt, 'ext_net', True, as_admin=True,
-                                     **kwargs)
+                                     arg_list=tuple(arg_dict.keys()),
+                                     **arg_dict)
         self._make_subnet(self.fmt, ext_net, '10.251.0.1', '10.251.0.0/24',
                           enable_dhcp=True)
         router = self._make_router(self.fmt, self._tenant_id)

neutron/tests/functional/services/ovn_l3/test_plugin.py

@@ -41,6 +41,7 @@ class TestRouter(base.TestOVNFunctionalBase):
         self.chassis2 = self.add_fake_chassis(
             'ovs-host2', physical_nets=['physnet2', 'physnet3'],
             enable_chassis_as_gw=True, azs=[])
+        self.physnet_used = ['physnet1', 'physnet2', 'physnet3']
         self.cr_lrp_pb_event = events.WaitForCrLrpPortBindingEvent()
         self.sb_api.idl.notify_handler.watch_event(self.cr_lrp_pb_event)
 
@@ -86,13 +87,11 @@ class TestRouter(base.TestOVNFunctionalBase):
                               ip_version=n_consts.IP_VERSION_4)
         return network
 
-    def _set_redirect_chassis_to_invalid_chassis(self, ovn_client):
+    def _unset_lrp_gw_chassis(self, ovn_client):
         with ovn_client._nb_idl.transaction(check_error=True) as txn:
-            for lrp in self.nb_api.tables[
-                    'Logical_Router_Port'].rows.values():
+            for lrp in self.nb_api.tables['Logical_Router_Port'].rows.values():
                 txn.add(ovn_client._nb_idl.update_lrouter_port(
-                    lrp.name,
-                    gateway_chassis=[ovn_const.OVN_GATEWAY_INVALID_CHASSIS]))
+                    lrp.name, gateway_chassis=[]))
 
     def _get_gwc_dict(self):
         sched_info = {}
@@ -117,11 +116,11 @@ class TestRouter(base.TestOVNFunctionalBase):
                 # exception occasionally.
                 continue
 
-            gw_port_id = router.get('gw_port_id')
-            logical_port = 'cr-lrp-%s' % gw_port_id
-            self.assertTrue(self.cr_lrp_pb_event.wait(logical_port),
-                            msg='lrp %s failed to bind' % logical_port)
             if bind_chassis:
+                gw_port_id = router.get('gw_port_id')
+                logical_port = 'cr-lrp-%s' % gw_port_id
+                self.assertTrue(self.cr_lrp_pb_event.wait(logical_port),
+                                msg='lrp %s failed to bind' % logical_port)
                 self.sb_api.lsp_bind(logical_port, bind_chassis,
                                      may_exist=True).execute(check_error=True)
         return routers
@@ -165,22 +164,24 @@ class TestRouter(base.TestOVNFunctionalBase):
         def fake_select(*args, **kwargs):
             self.assertCountEqual(candidates, kwargs['candidates'])
             # We are not interested in further processing, let us return
-            # INVALID_CHASSIS to avoid errors
-            return [ovn_const.OVN_GATEWAY_INVALID_CHASSIS]
+            # a random chassis name to avoid errors. If there are no
+            # candidates, this method returns None.
+            return ['a-random-chassis'] if candidates else None
 
         with mock.patch.object(self.l3_plugin.scheduler, 'select',
-                              side_effect=fake_select) as plugin_select:
+                               side_effect=fake_select) as plugin_select:
             gw_info = {'network_id': ext1['network']['id']}
             self._create_router('router1', gw_info=gw_info,
                                 az_hints=router_az_hints)
             self.assertTrue(plugin_select.called)
             plugin_select.reset_mock()
 
-            # set redirect-chassis to neutron-ovn-invalid-chassis, so
-            # that schedule_unhosted_gateways will try to schedule it
-            self._set_redirect_chassis_to_invalid_chassis(ovn_client)
+            # Unset the redirect-chassis so that schedule_unhosted_gateways
+            # will try to schedule it.
+            self._unset_lrp_gw_chassis(ovn_client)
             self.l3_plugin.schedule_unhosted_gateways()
-            self.assertTrue(plugin_select.called)
+            check = self.assertTrue if candidates else self.assertFalse
+            check(plugin_select.called)
 
     def test_gateway_chassis_with_cms_and_bridge_mappings(self):
         # Both chassis1 and chassis3 are having proper bridge mappings,
@@ -201,7 +202,7 @@ class TestRouter(base.TestOVNFunctionalBase):
             'ext1', 'vlan', 'physnet1', 1, "10.0.0.1", "10.0.0.0/24")
         # As we have 'gateways' in the system, but without required
         # chassis we should not schedule gw in that case at all.
-        self._set_redirect_chassis_to_invalid_chassis(ovn_client)
+        self._unset_lrp_gw_chassis(ovn_client)
         with mock.patch.object(self.l3_plugin.scheduler, 'select',
                                side_effect=[self.chassis1]):
             gw_info = {'network_id': ext1['network']['id']}
@@ -242,7 +243,7 @@ class TestRouter(base.TestOVNFunctionalBase):
             'ext1', 'vlan', 'physnet1', 1, "10.0.0.1", "10.0.0.0/24")
         # As we have 'gateways' in the system, but without required
         # chassis we should not schedule gw in that case at all.
-        self._set_redirect_chassis_to_invalid_chassis(ovn_client)
+        self._unset_lrp_gw_chassis(ovn_client)
         with mock.patch.object(self.l3_plugin.scheduler, 'select',
                                side_effect=[self.chassis1]):
             gw_info = {'network_id': ext1['network']['id']}
@@ -264,7 +265,7 @@ class TestRouter(base.TestOVNFunctionalBase):
     def test_gateway_chassis_no_physnet_tunnelled_network(self):
         # The GW network is tunnelled, no physnet defined --> no possible
         # candidates.
-        self._check_gateway_chassis_candidates([], physnet=None)
+        self._check_gateway_chassis_candidates(None, physnet=None)
 
     def test_gateway_chassis_least_loaded_scheduler(self):
         # This test will create 4 routers each with its own gateway.
@@ -372,11 +373,8 @@ class TestRouter(base.TestOVNFunctionalBase):
         Test cases when subnets are added to an external network after router
         has been configured to use that network via "set --external-gateway"
         """
-
         with mock.patch.object(self.l3_plugin.scheduler, 'select',
-                               return_value=[
-                                   ovn_const.OVN_GATEWAY_INVALID_CHASSIS
-                               ]) as plugin_select:
+                               return_value=self.chassis1) as plugin_select:
             router1 = self._create_router('router1', gw_info=None)
             router_id = router1['id']
             self.assertIsNone(self._get_gw_port(router_id),
@@ -490,8 +488,8 @@ class TestRouter(base.TestOVNFunctionalBase):
         def fake_select(*args, **kwargs):
             self.assertCountEqual(self.candidates, kwargs['candidates'])
             # We are not interested in further processing, let us return
-            # INVALID_CHASSIS to avoid errors
-            return [ovn_const.OVN_GATEWAY_INVALID_CHASSIS]
+            # a random chassis name to avoid errors.
+            return ['a-random-chassis']
 
         with mock.patch.object(self.l3_plugin.scheduler, 'select',
                                side_effect=fake_select) as plugin_select:
@@ -499,9 +497,9 @@ class TestRouter(base.TestOVNFunctionalBase):
             gw_info = {'network_id': ext1['network']['id']}
             router1 = self._create_router('router1', gw_info=gw_info)
 
-            # set redirect-chassis to neutron-ovn-invalid-chassis, so
-            # that schedule_unhosted_gateways will try to schedule it
-            self._set_redirect_chassis_to_invalid_chassis(ovn_client)
+            # Unset the redirect-chassis so that schedule_unhosted_gateways
+            # will try to schedule it.
+            self._unset_lrp_gw_chassis(ovn_client)
             self.l3_plugin.schedule_unhosted_gateways()
 
             self.candidates = [self.chassis1, self.chassis2]
@@ -509,7 +507,7 @@ class TestRouter(base.TestOVNFunctionalBase):
             self.l3_plugin.update_router(
                 self.context, router1['id'],
                 {'router': {l3_apidef.EXTERNAL_GW_INFO: gw_info}})
-            self._set_redirect_chassis_to_invalid_chassis(ovn_client)
+            self._unset_lrp_gw_chassis(ovn_client)
             self.l3_plugin.schedule_unhosted_gateways()
 
             self.candidates = []
@@ -517,17 +515,17 @@ class TestRouter(base.TestOVNFunctionalBase):
             self.l3_plugin.update_router(
                 self.context, router1['id'],
                 {'router': {l3_apidef.EXTERNAL_GW_INFO: gw_info}})
-            self._set_redirect_chassis_to_invalid_chassis(ovn_client)
+            self._unset_lrp_gw_chassis(ovn_client)
             self.l3_plugin.schedule_unhosted_gateways()
 
             # We can't test call_count for these mocks, as we have disabled
             # maintenance_worker which will trigger chassis events
             # and eventually calling schedule_unhosted_gateways.
-            # However, we know for sure that these mocks must have been
-            # called at least 3 times because that is the number of times
-            # this test invokes them: 1x create_router + 2x update_router;
-            # and 3x schedule_unhosted_gateways for plugin_select mock.
-            self.assertGreaterEqual(plugin_select.call_count, 3)
+            # The router is created with a gateway port and updated twice.
+            # However, the "plugin_select" is called only twice because the
+            # third gateway network used is type "geneve" and the LRP are not
+            # hosted in any chassis.
+            self.assertGreaterEqual(plugin_select.call_count, 2)
 
     def test_router_gateway_port_binding_host_id(self):
         # Test setting chassis on chassisredirect port in Port_Binding table,
@@ -613,7 +611,8 @@ class TestRouter(base.TestOVNFunctionalBase):
 
     def test_create_delete_router_multiple_gw_ports(self):
         ext4 = self._create_ext_network(
-            'ext4', 'flat', 'physnet4', None, "40.0.0.1", "40.0.0.0/24")
+            'ext4', 'flat', self.physnet_used[0], None, '40.0.0.1',
+            '40.0.0.0/24')
         router = self._create_router('router4')
         gws = self._add_external_gateways(
             router['id'],
@@ -638,7 +637,8 @@ class TestRouter(base.TestOVNFunctionalBase):
 
     def test_create_router_multiple_gw_ports_ecmp(self):
         ext5 = self._create_ext_network(
-            'ext5', 'flat', 'physnet5', None, "10.0.50.1", "10.0.50.0/24")
+            'ext5', 'flat', self.physnet_used[1], None, '10.0.50.1',
+            '10.0.50.0/24')
         router = self._create_router('router5', enable_ecmp=True)
         gws = self._add_external_gateways(
             router['id'],
@@ -740,12 +740,10 @@ class TestRouter(base.TestOVNFunctionalBase):
             'ext1', 'flat', 'physnet6', None, "10.0.60.1", "10.0.60.0/24")
         gw_info = {'network_id': ext1['network']['id']}
 
-        # Attempt to add 4 routers, since there are no chassis all will be
-        # scheduled on the ovn_const.OVN_GATEWAY_INVALID_CHASSIS.
-        num_routers = len(self._create_routers_wait_pb(1, 4, gw_info))
-        self.assertEqual(
-            {ovn_const.OVN_GATEWAY_INVALID_CHASSIS: {1: num_routers}},
-            self._get_gwc_dict())
+        # Attempt to add 4 routers, since there are no chassis, none of them
+        # will be scheduled on any chassis.
+        num_routers = len(self._create_routers_wait_pb(1, 4, gw_info=gw_info))
+        self.assertEqual({}, self._get_gwc_dict())
 
         # Add 2 chassis and rebalance gateways.
         #
@@ -758,9 +756,7 @@ class TestRouter(base.TestOVNFunctionalBase):
         with mock.patch.object(
                 self.l3_plugin, 'schedule_unhosted_gateways'):
             chassis_list.extend(self._add_chassis(1, 2, ['physnet6']))
-        self.assertEqual(
-            {ovn_const.OVN_GATEWAY_INVALID_CHASSIS: {1: num_routers}},
-            self._get_gwc_dict())
+        self.assertEqual({}, self._get_gwc_dict())
 
         # Wrap `self.l3_plugin._nb_ovn.transaction` so that we can assert on
         # number of calls.

neutron/tests/unit/common/ovn/test_utils.py

@@ -266,7 +266,7 @@ class TestGateWayChassisValidity(base.BaseTestCase):
 
     def test_gateway_chassis_due_to_invalid_chassis_name(self):
         # Return True since chassis is invalid
-        self.chassis_name = constants.OVN_GATEWAY_INVALID_CHASSIS
+        self.chassis_name = None
         self.assertTrue(utils.is_gateway_chassis_invalid(
             self.chassis_name, self.gw_chassis, self.physnet,
             self.chassis_physnets, self.az_hints, self.chassis_azs))

neutron/tests/unit/plugins/ml2/drivers/ovn/mech_driver/ovsdb/test_impl_idl_ovn.py

@@ -181,8 +181,7 @@ class TestNBImplIdlOvn(TestDBImplIdlOvn):
              'external_ids': {ovn_const.OVN_ROUTER_NAME_EXT_ID_KEY: 'lr-id-a',
                               ovn_const.OVN_ROUTER_IS_EXT_GW: str(True)},
              'networks': ['10.0.3.0/24'],
-             'options': {ovn_const.OVN_GATEWAY_CHASSIS_KEY:
-                         ovn_const.OVN_GATEWAY_INVALID_CHASSIS}},
+             'options': {ovn_const.OVN_GATEWAY_CHASSIS_KEY: None}},
             {'name': 'xrp-id-b1',
              'external_ids': {}, 'networks': ['20.0.1.0/24']},
             {'name': utils.ovn_lrouter_port_name('orp-id-b2'),
@@ -627,8 +626,7 @@ class TestNBImplIdlOvn(TestDBImplIdlOvn):
         expected = {'host-1': [utils.ovn_lrouter_port_name('orp-id-a1'),
                                utils.ovn_lrouter_port_name('orp-id-a2')],
                     'host-2': [utils.ovn_lrouter_port_name('orp-id-b2')],
-                    ovn_const.OVN_GATEWAY_INVALID_CHASSIS: [
-                        utils.ovn_name('orp-id-a3')]}
+                    }
         self.assertCountEqual(bindings, expected)
 
         bindings = self.nb_ovn_idl.get_all_chassis_gateway_bindings([])
@@ -654,7 +652,7 @@ class TestNBImplIdlOvn(TestDBImplIdlOvn):
         self.assertEqual(chassis, ['host-2'])
         chassis = self.nb_ovn_idl.get_gateway_chassis_binding(
             utils.ovn_lrouter_port_name('orp-id-a3'))
-        self.assertEqual(chassis, ['neutron-ovn-invalid-chassis'])
+        self.assertEqual([], chassis)
         chassis = self.nb_ovn_idl.get_gateway_chassis_binding(
             utils.ovn_lrouter_port_name('orp-id-b3'))
         self.assertEqual([], chassis)

neutron/tests/unit/scheduler/test_l3_ovn_scheduler.py

@@ -50,8 +50,7 @@ class TestOVNGatewayScheduler(base.BaseTestCase):
         self.new_gateway_name = 'lrp_new'
         self.fake_chassis_gateway_mappings = {
             'None': {'Chassis': [],
-                     'Gateways': {
-                         'g1': [ovn_const.OVN_GATEWAY_INVALID_CHASSIS]}},
+                     'Gateways': {'g1': None}},
             'Multiple1': {'Chassis': ['hv1', 'hv2', 'hv3', 'hv4', 'hv5'],
                           'Gateways': {
                               'g1': ['hv1', 'hv2', 'hv4', 'hv3', 'hv5'],
@@ -102,6 +101,7 @@ class TestOVNGatewayScheduler(base.BaseTestCase):
             for chassis in details['Chassis']:
                 details['Chassis_Bindings'].setdefault(chassis, [])
             for gw, chassis_list in details['Gateways'].items():
+                chassis_list = chassis_list or []
                 max_prio = len(chassis_list)
                 for idx, chassis in enumerate(chassis_list):
                     prio = max_prio - idx
@@ -138,7 +138,7 @@ class OVNGatewayChanceScheduler(TestOVNGatewayScheduler):
         gateway_name = random.choice(list(mapping['Gateways'].keys()))
         chassis = self.select(mapping, gateway_name, chassis_and_azs,
                               candidates=mapping['Chassis'])
-        self.assertEqual([ovn_const.OVN_GATEWAY_INVALID_CHASSIS], chassis)
+        self.assertIsNone(chassis)
 
     def test_no_chassis_available_for_new_gateway(self):
         mapping = self.fake_chassis_gateway_mappings['None']
@@ -146,7 +146,7 @@ class OVNGatewayChanceScheduler(TestOVNGatewayScheduler):
         gateway_name = self.new_gateway_name
         chassis = self.select(mapping, gateway_name, chassis_and_azs,
                               candidates=mapping['Chassis'])
-        self.assertEqual([ovn_const.OVN_GATEWAY_INVALID_CHASSIS], chassis)
+        self.assertIsNone(chassis)
 
     def test_random_chassis_available_for_new_gateway(self):
         mapping = self.fake_chassis_gateway_mappings['Multiple1']
@@ -161,7 +161,7 @@ class OVNGatewayChanceScheduler(TestOVNGatewayScheduler):
         chassis_and_azs = self.fake_chassis_and_azs['None']
         gateway_name = self.new_gateway_name
         chassis = self.select(mapping, gateway_name, chassis_and_azs)
-        self.assertEqual([ovn_const.OVN_GATEWAY_INVALID_CHASSIS], chassis)
+        self.assertIsNone(chassis)
         self.mock_log.warning.assert_called_once_with(
             'Gateway %s was not scheduled on any chassis, no candidates are '
             'available', gateway_name)
@@ -179,15 +179,14 @@ class OVNGatewayChanceScheduler(TestOVNGatewayScheduler):
                 nb_idl=nb_idl, gw_chassis=["temp"],
                 physnet='phys-network-1',
                 chassis_physnets=chassis_physnets,
-                existing_chassis=['temp',
-                                  ovn_const.OVN_GATEWAY_INVALID_CHASSIS]))
+                existing_chassis=['temp', None]))
         # Check if invalid is removed -II
         self.assertFalse(
             self.filter_existing_chassis(
                 nb_idl=nb_idl, gw_chassis=["temp"],
                 physnet='phys-network-1',
                 chassis_physnets=chassis_physnets,
-                existing_chassis=[ovn_const.OVN_GATEWAY_INVALID_CHASSIS]))
+                existing_chassis=None))
         # Check if chassis removed when physnet doesnt exist
         self.assertFalse(
             self.filter_existing_chassis(
@@ -236,7 +235,7 @@ class OVNGatewayLeastLoadedScheduler(TestOVNGatewayScheduler):
         gateway_name = random.choice(list(mapping['Gateways'].keys()))
         chassis = self.select(mapping, gateway_name, chassis_and_azs,
                               candidates=mapping['Chassis'])
-        self.assertEqual([ovn_const.OVN_GATEWAY_INVALID_CHASSIS], chassis)
+        self.assertIsNone(chassis)
 
     def test_no_chassis_available_for_new_gateway(self):
         mapping = self.fake_chassis_gateway_mappings['None']
@@ -244,7 +243,7 @@ class OVNGatewayLeastLoadedScheduler(TestOVNGatewayScheduler):
         gateway_name = self.new_gateway_name
         chassis = self.select(mapping, gateway_name, chassis_and_azs,
                               candidates=mapping['Chassis'])
-        self.assertEqual([ovn_const.OVN_GATEWAY_INVALID_CHASSIS], chassis)
+        self.assertIsNone(chassis)
 
     def test_least_loaded_chassis_available_for_new_gateway1(self):
         mapping = self.fake_chassis_gateway_mappings['Multiple1']

releasenotes/notes/ovn-l3-scheduler-unbound-gw-ports-46ced10f810d845d.yaml

@@ -0,0 +1,13 @@
+---
+other:
+  - |
+    The artifact of creating a gateway chassis called
+    "neutron-ovn-invalid-chassis" when a "Logical_Router_Port" cannot be
+    assigned to any chassis is removed. Now no gateway chassis is created and
+    the "Logical_Router_Port" field will be empty.
+upgrade:
+  - |
+    Any "Logical_Router_Port" with a gateway chassis named
+    "neutron-ovn-invalid-chassis" will be updated and this chassis will be
+    deleted. An unhosted (unbound) "Logical_Router_Port" will have no gateway
+    assigned.