[OVN] Ensure traffic for provider vlan networks is not tunneled

This patch adds an extra checking to ensure the
"reside-on-redirect-chassis" is set to true for the logical
router port associated to vlan provider network despite having
the "ovn_distributed_floating_ip" enabled or not. This is needed
as there is an OVN bug [1] making it not work as expected.

Note setting this to true has implications as the traffic will be
centrallized (but not tunneled) through the node with the gateway
port.

The expected behavior of this flag, once [1] is fixed is:
- reside-on-redirect-chassis flag to False: means traffic goes
  tunneled to the controller with the gateway port. Means it requires
  extra MTU reduction to work.
- reside-on-redirect-chassis flag to True: means traffic is not
  tunneled to the controller with the gateway port, but the traffic is
  centralized through the controller with the gateway port. Thus it
  does not require extra MTU reduction.
- reside-on-redirect-chassis to False, but with ovn-chassis-mac-mappings
  configured: means the traffic is fully distributed and it is not being
  tunneled, nor sent, through the controller with the gateway port. This
  is the preferred option as it does not require MTU reduction and it
  avoids the extra hop. However it is not working as expected, therefore
  the fallback to set reside-on-redirect-chassis to True.

[1] https://bugzilla.redhat.com/show_bug.cgi?id=2162756

Closes-Bug: #2003455
Change-Id: I662cb30c842e54bb9f7dabac5519283aa7c7f8d0

2 files changed, 12 insertions, 5 deletions

diff --git a/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/maintenance.py b/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/maintenance.py
index dd4292abf6..84a205a84b 100644
--- a/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/maintenance.py
+++ b/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/maintenance.py
@@ -725,7 +725,10 @@ class DBInconsistenciesPeriodics(SchemaAwarePeriodicsBase):
         # Get router ports belonging to VLAN networks
         vlan_nets = self._ovn_client._plugin.get_networks(
             context, {pnet.NETWORK_TYPE: [n_const.TYPE_VLAN]})
-        vlan_net_ids = [vn['id'] for vn in vlan_nets]
+        # FIXME(ltomasbo): Once Bugzilla 2162756 is fixed the
+        # is_provider_network check should be removed
+        vlan_net_ids = [vn['id'] for vn in vlan_nets
+                        if not utils.is_provider_network(vn)]
         router_ports = self._ovn_client._plugin.get_ports(
             context, {'network_id': vlan_net_ids,
                       'device_owner': n_const.ROUTER_PORT_OWNERS})
diff --git a/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/ovn_client.py b/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/ovn_client.py
index cab0b25937..1aa80f58cb 100644
--- a/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/ovn_client.py
+++ b/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/ovn_client.py
@@ -1252,7 +1252,7 @@ class OVNClient(object):
                 # leak the RAs generated for the tenant networks via the
                 # provider network
                 ipv6_ra_configs['send_periodic'] = 'true'
-                if is_gw_port and utils.is_provider_network(net):
+                if is_gw_port and utils.is_external_network(net):
                     ipv6_ra_configs['send_periodic'] = 'false'
                 ipv6_ra_configs['mtu'] = str(net['mtu'])
 
@@ -1578,9 +1578,12 @@ class OVNClient(object):
         # logical router port is centralized in the chassis hosting the
         # distributed gateway port.
         # https://github.com/openvswitch/ovs/commit/85706c34d53d4810f54bec1de662392a3c06a996
+        # FIXME(ltomasbo): Once Bugzilla 2162756 is fixed the
+        # is_provider_network check should be removed
         if network.get(pnet.NETWORK_TYPE) == const.TYPE_VLAN:
             options[ovn_const.LRP_OPTIONS_RESIDE_REDIR_CH] = (
-                'false' if ovn_conf.is_ovn_distributed_floating_ip()
+                'false' if (ovn_conf.is_ovn_distributed_floating_ip() and
+                            not utils.is_provider_network(network))
                 else 'true')
 
         is_gw_port = const.DEVICE_OWNER_ROUTER_GW == port.get(
@@ -1995,8 +1998,9 @@ class OVNClient(object):
                 for subnet in subnets:
                     self.update_subnet(context, subnet, network, txn)
 
-                if utils.is_provider_network(network):
-                    # make sure to use admin context as this is a providernet
+                if utils.is_external_network(network):
+                    # make sure to use admin context as this is a external
+                    # network
                     self.set_gateway_mtu(n_context.get_admin_context(),
                                          network, txn)