Add support for vlan transparency in the OVN driver

This patch adds support for vlan_transparent in the ovn mechanism
driver. So ovn is now second mech_driver after linuxbridge which can be
used with vlan_transparent networks.
It just adds "vlan-passthru" option to the Logical Switch's "other
config".
This needs also changes in the core OVN which are available only in OVN
master branch for now. See [1] for details.

[1] https://patchwork.ozlabs.org/project/ovn/patch/20201110023449.194642-1-ihrachys@redhat.com/

Change-Id: I76b8ba959398dcffff112d26ae7d81ff428be992

neutron/common/ovn/constants.py

@@ -291,3 +291,6 @@ NEUTRON_AVAILABILITY_ZONES = 'neutron-availability-zones'
 OVN_CMS_OPTIONS = 'ovn-cms-options'
 CMS_OPT_CHASSIS_AS_GW = 'enable-chassis-as-gw'
 CMS_OPT_AVAILABILITY_ZONES = 'availability-zones'
+
+# OVN vlan transparency option
+VLAN_PASSTHRU = 'vlan-passthru'

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

@@ -152,6 +152,10 @@ class OVNMechanismDriver(api.MechanismDriver):
     def sb_ovn(self):
         return self._sb_ovn
 
+    def check_vlan_transparency(self, context):
+        """OVN driver vlan transparency support."""
+        return True
+
     def _setup_vif_port_bindings(self):
         self.supported_vnic_types = [portbindings.VNIC_NORMAL,
                                      portbindings.VNIC_DIRECT,

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

@@ -1588,8 +1588,11 @@ class OVNClient(object):
 
         # Enable IGMP snooping if igmp_snooping_enable is enabled in Neutron
         value = 'true' if ovn_conf.is_igmp_snooping_enabled() else 'false'
+        vlan_transparent = (
+            'true' if network.get('vlan_transparent') else 'false')
         params['other_config'] = {ovn_const.MCAST_SNOOP: value,
-                                  ovn_const.MCAST_FLOOD_UNREGISTERED: value}
+                                  ovn_const.MCAST_FLOOD_UNREGISTERED: value,
+                                  ovn_const.VLAN_PASSTHRU: vlan_transparent}
         return params
 
     def create_network(self, context, network):

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

@@ -83,6 +83,7 @@ class TestOVNMechanismDriver(test_plugin.Ml2PluginV2TestCase):
                                        group='ovn')
         ovn_conf.cfg.CONF.set_override('dns_servers', ['8.8.8.8'],
                                        group='ovn')
+        cfg.CONF.set_override('vlan_transparent', True)
         super(TestOVNMechanismDriver, self).setUp()
         mm = directory.get_plugin().mechanism_manager
         self.mech_driver = mm.mech_drivers['ovn'].obj
@@ -717,7 +718,8 @@ class TestOVNMechanismDriver(test_plugin.Ml2PluginV2TestCase):
             ovn_utils.ovn_name(net['id']), external_ids=mock.ANY,
             may_exist=True,
             other_config={ovn_const.MCAST_SNOOP: value,
-                          ovn_const.MCAST_FLOOD_UNREGISTERED: value})
+                          ovn_const.MCAST_FLOOD_UNREGISTERED: value,
+                          ovn_const.VLAN_PASSTHRU: 'false'})
 
     def test_create_network_igmp_snoop_enabled(self):
         self._create_network_igmp_snoop(enabled=True)
@@ -725,6 +727,25 @@ class TestOVNMechanismDriver(test_plugin.Ml2PluginV2TestCase):
     def test_create_network_igmp_snoop_disabled(self):
         self._create_network_igmp_snoop(enabled=False)
 
+    def _create_network_vlan_passthru(self, enabled):
+        nb_idl = self.mech_driver._ovn_client._nb_idl
+        net = self._make_network(self.fmt, name='net1',
+                                 admin_state_up=True,
+                                 vlan_transparent=enabled)['network']
+        value = 'true' if enabled else 'false'
+        nb_idl.ls_add.assert_called_once_with(
+            ovn_utils.ovn_name(net['id']), external_ids=mock.ANY,
+            may_exist=True,
+            other_config={ovn_const.MCAST_SNOOP: 'false',
+                          ovn_const.MCAST_FLOOD_UNREGISTERED: 'false',
+                          ovn_const.VLAN_PASSTHRU: value})
+
+    def test_create_network_vlan_passthru_enabled(self):
+        self._create_network_vlan_passthru(enabled=True)
+
+    def test_create_network_vlan_passthru_disabled(self):
+        self._create_network_vlan_passthru(enabled=False)
+
     def test_create_network_create_localnet_port_tunnel_network_type(self):
         nb_idl = self.mech_driver._ovn_client._nb_idl
         self._make_network(self.fmt, name='net1',

releasenotes/notes/ovn-driver-adds-support-for-vlan-transparency-3ac9d965f5093a15.yaml

@@ -0,0 +1,4 @@
+---
+features:
+  - |
+    Added support for the ``vlan-transparent`` in the OVN mechanism driver.