Add external_ids:ovn-chassis-mac-mappings

The ovn-chassis-mac-mappings allows a chassis to replace the vrouter
MAC address with the MAC address of the physical network if the packet
is going from a distributed router port on vlan type logical switch.

This in essence makes VLAN tenant network distributed ports work just
like geneve distributed ports.

Closes-Bug: #2084127

Signed-off-by: Gabriel Adrian Samfira <[email protected]>

lib/charms/ovn_charm.py

@@ -27,6 +27,7 @@
 import charmhelpers.contrib.network.ovs as ch_ovs
 import charmhelpers.contrib.network.ovs.ovsdb as ch_ovsdb
 import charmhelpers.contrib.openstack.deferred_events as deferred_events
+import charmhelpers.core.host as ch_host
 import charmhelpers.fetch as ch_fetch
 
 import charms_openstack.adapters
@@ -1297,6 +1298,12 @@ def configure_bridges(self):
                 'other-config': {'disable-in-band': 'true'},
             },
         })
+
+        # We need to build a mac mapping to enable distributed ports on tenant
+        # VLAN networks.
+        # see: https://www.ovn.org/support/dist-docs/ovn-architecture.7.html
+        ovn_chassis_mac_mapping = ''
+
         for br in bim:
             if br not in ovnbridges:
                 continue
@@ -1328,13 +1335,37 @@ def configure_bridges(self):
                                            portdata={
                                                'external-ids': {
                                                    'charm-ovn-chassis': br}})
+            # We can use the MAC of the bridge as the unique chassis MAC. If
+            # a physical port has been added to the bridge, the MAC will most
+            # likely be inherited. If not, a unique mac will be generated
+            # anyway.
+            hw_addr = None
+            try:
+                hw_addr = ch_host.get_nic_hwaddr(br)
+            except Exception as err:
+                ch_core.hookenv.log('failed to get MAC for bridge "{}": {}'
+                                    .format(br, err),
+                                    level=ch_core.hookenv.ERROR)
+            if hw_addr:
+                networks = ovnbridges.get(br, [])
+                for net in networks:
+                    if ovn_chassis_mac_mapping:
+                        ovn_chassis_mac_mapping += ','
+                    ovn_chassis_mac_mapping += '{}:{}'.format(
+                        net, hw_addr)
 
         opvs = ch_ovsdb.SimpleOVSDB('ovs-vsctl').open_vswitch
         if ovn_br_map_str:
             opvs.set('.', 'external_ids:ovn-bridge-mappings', ovn_br_map_str)
         else:
             opvs.remove('.', 'external_ids', 'ovn-bridge-mappings')
 
+        if ovn_chassis_mac_mapping:
+            opvs.set('.', 'external_ids:ovn-chassis-mac-mappings',
+                     ovn_chassis_mac_mapping)
+        else:
+            opvs.remove('.', 'external_ids', 'ovn-chassis-mac-mappings')
+
         cms_opts = self._get_ovn_cms_options()
         if cms_opts:
             opvs.set('.', 'external_ids:ovn-cms-options', ','.join(cms_opts))

unit_tests/test_lib_charms_ovn_charm.py

@@ -781,6 +781,18 @@ def test__init__(self):
         })
 
     def test_configure_bridges(self):
+        def mock_get_nic_hwaddr_fn(iface):
+            mac_mapping = {
+                "br-ex": "a0:36:9f:dd:37:dd",
+                "br-data": "a0:36:9f:dd:37:db",
+            }
+            return mac_mapping.get(iface, "")
+        mock_get_nic_hwaddr = mock.MagicMock()
+        mock_get_nic_hwaddr.side_effect = mock_get_nic_hwaddr_fn
+
+        self.patch_object(ovn_charm.ch_host, "get_nic_hwaddr")
+        self.get_nic_hwaddr.side_effect = mock_get_nic_hwaddr
+
         self.patch_object(ovn_charm.os_context, 'BridgePortInterfaceMap')
         dict_bpi = {
             'br-ex': {     # bridge
@@ -891,10 +903,17 @@ def test_configure_bridges(self):
                 'data': 'fake',
                 'external-ids': {'charm-ovn-chassis': 'br-ex'}},
             linkup=False, promisc=None, portdata={
-                'external-ids': {'charm-ovn-chassis': 'br-ex'}}),
-        ovsdb.open_vswitch.set.assert_called_once_with(
-            '.', 'external_ids:ovn-bridge-mappings',
-            'other:br-data,provider:br-ex')
+                'external-ids': {'charm-ovn-chassis': 'br-ex'}})
+        ovsdb.open_vswitch.set.assert_has_calls([
+            mock.call(
+                '.', 'external_ids:ovn-bridge-mappings',
+                'other:br-data,provider:br-ex'
+            ),
+            mock.call(
+                '.', 'external_ids:ovn-chassis-mac-mappings',
+                'provider:a0:36:9f:dd:37:dd,other:a0:36:9f:dd:37:db'
+            ),
+        ], any_order=False)
         ovsdb.open_vswitch.remove.assert_called_once_with(
             '.', 'external_ids', 'ovn-cms-options')