[OVN] Accept OVS system-id as non UUID formatted string

Accept OVS system-id non UUID formatted strings. The OVN metadata
agent will generate a unique UUID from the OVS system-id. If this
string is a UUID, this value will be used. If not, the OVN metadata
agent will generate a UUID based on the provided string.

This patch amends [1].

[1]https://review.opendev.org/c/openstack/neutron/+/819634

Closes-Bug: #1952550

Conflicts:
	neutron/agent/ovn/metadata/agent.py
        neutron/tests/unit/agent/ovn/metadata/test_agent.py

Change-Id: I42a8a767a6ef9454419b26f80339394759644faf
(cherry picked from commit 79037c9516)
(cherry picked from commit 6da4432fed)
(cherry picked from commit b07eeb2789)
(cherry picked from commit 4bf531448e)

neutron/agent/ovn/metadata/agent.py

@@ -14,12 +14,12 @@
 
 import collections
 import re
+import uuid
 
 from neutron_lib import constants as n_const
 from oslo_concurrency import lockutils
 from oslo_log import log
 from oslo_utils import netutils
-from oslo_utils import uuidutils
 from ovsdbapp.backend.ovs_idl import event as row_event
 from ovsdbapp.backend.ovs_idl import vlog
 import six
@@ -48,6 +48,8 @@ OVN_VIF_PORT_TYPES = ("", "external", )
 MetadataPortInfo = collections.namedtuple('MetadataPortInfo', ['mac',
                                                                'ip_addresses'])
 
+OVN_METADATA_UUID_NAMESPACE = uuid.UUID('d34bf9f6-da32-4871-9af8-15a4626b41ab')
+
 
 def _sync_lock(f):
     """Decorator to block all operations for a global sync call."""
@@ -185,9 +187,16 @@ class MetadataAgent(object):
 
     def _load_config(self):
         self.chassis = self._get_own_chassis_name()
+        try:
+            self.chassis_id = uuid.UUID(self.chassis)
+        except ValueError:
+            # OVS system-id could be a non UUID formatted string.
+            self.chassis_id = uuid.uuid5(OVN_METADATA_UUID_NAMESPACE,
+                                         self.chassis)
+
         self.ovn_bridge = self._get_ovn_bridge()
-        LOG.debug("Loaded chassis %s and ovn bridge %s.",
-                  self.chassis, self.ovn_bridge)
+        LOG.info("Loaded chassis name %s (UUID: %s) and ovn bridge %s.",
+                 self.chassis, self.chassis_id, self.ovn_bridge)
 
     @_sync_lock
     def resync(self):
@@ -245,8 +254,9 @@ class MetadataAgent(object):
         # NOTE(lucasagomes): db_add() will not overwrite the UUID if
         # it's already set.
         table = ('Chassis_Private' if self.has_chassis_private else 'Chassis')
-        ext_ids = {
-            ovn_const.OVN_AGENT_METADATA_ID_KEY: uuidutils.generate_uuid()}
+        # Generate unique, but consistent metadata id for chassis name
+        agent_id = uuid.uuid5(self.chassis_id, 'metadata_agent')
+        ext_ids = {ovn_const.OVN_AGENT_METADATA_ID_KEY: str(agent_id)}
         self.sb_idl.db_add(table, self.chassis, 'external_ids',
                            ext_ids).execute(check_error=True)
 

neutron/tests/unit/agent/ovn/metadata/test_agent.py

@@ -13,10 +13,12 @@
 # limitations under the License.
 
 import collections
+import uuid
 
 import mock
 from oslo_config import cfg
 from oslo_config import fixture as config_fixture
+from oslo_utils import uuidutils
 
 from neutron.agent.linux import ip_lib
 from neutron.agent.linux.ip_lib import IpAddrCommand as ip_addr
@@ -322,3 +324,24 @@ class TestMetadataAgent(base.BaseTestCase):
         expected_dps = ['0', '1', '2']
         self._test_update_chassis_metadata_networks_helper(
             dp, remove, expected_dps, txn_called=False)
+
+    def test__load_config(self):
+        # Chassis name UUID formatted string. OVN bridge "br-ovn".
+        valid_uuid_str = uuidutils.generate_uuid()
+        self.agent.ovs_idl.db_get.return_value.execute.side_effect = [
+            {'system-id': valid_uuid_str}, {'ovn-bridge': 'br-ovn'}]
+        self.agent._load_config()
+        self.assertEqual(valid_uuid_str, self.agent.chassis)
+        self.assertEqual(uuid.UUID(valid_uuid_str), self.agent.chassis_id)
+        self.assertEqual('br-ovn', self.agent.ovn_bridge)
+
+        # Chassis name non UUID formatted string. OVN bridge not defined,
+        # "br-int" assigned by default.
+        self.agent.ovs_idl.db_get.return_value.execute.side_effect = [
+            {'system-id': 'RandomName1'}, {}]
+        self.agent._load_config()
+        generated_uuid = uuid.uuid5(agent.OVN_METADATA_UUID_NAMESPACE,
+                                    'RandomName1')
+        self.assertEqual('RandomName1', self.agent.chassis)
+        self.assertEqual(generated_uuid, self.agent.chassis_id)
+        self.assertEqual('br-int', self.agent.ovn_bridge)