Comment 2 for bug 1761722

I think the part of your config that is causing the problems is:

host_bind_override: "eth12"

If your metal hosts have a br-vlan, then you can just remove that. If you opted not to make the br-vlan bridge on your non-container hosts, then you would change that value to the physical interface that would equate to br-vlan on your container hosts.

The veth interface name can be set to anything sensible, there is no OSA standard to use 'eth12' for any specific purpose.

You don't need to use both 'flat' and 'vlan' provider networks. For simplicity, you may just want to remove the flat provider network definition. The difference between them is just that one allows you to configure the segment ID (VLAN ID) either from within OpenStack ('vlan') or not from within OpenStack ('flat'), which would require you to configure all the VLAN sub-interfaces on the linux host manually.