Comment 0 for bug 2030773

Reported at: https://bugzilla.redhat.com/show_bug.cgi?id=2225156

The ovn-db-sync script does not check if the router ports are actually out-of-sync before adding it to the list of ports that needs to be updated, this can create red herring problems by introducing an irrelevant piece of information [0] in the sync report (specially when ran in "log" mode) making the user think that the databases might be out-of-sync even when it is not.

Looking at the code [1] we can see that the comment talks about checking the networks and ipv6_ra_configs changes but it does neither; instead, it adds every router port to the list of ports that needs to be updated.

<snipet>

# We dont have to check for the networks and
# ipv6_ra_configs values. Lets add it to the
# update_lrport_list. If they are in sync, then
# update_router_port will be a no-op.
update_lrport_list.append(db_router_ports[lrport])

</snipet>

This LP is about changing this behavior and checking for such differences in the router ports before marking them to be updated.

[0]
2023-07-24 11:46:31.391 952358 WARNING networking_ovn.ovn_db_sync [req-1081a8a6-82dd-431c-a2ab-f58741dc1677 - - - - -] Router Port port_id=f164c0f1-8ac8-4c45-bba9-8c723a30c701 needs to be updated for networks changed

[1]
https://github.com/openstack/neutron/blob/c453813d0664259c4da0d132f224be2eebe70072/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/ovn_db_sync.py#L553-L557