Comment 2 for bug 1813789

What's probably happening is we're getting the network-vif-plugged event due to the port binding change here:

https://github.com/openstack/nova/blob/a4e6340bdcc2fda8fed41abc64ea554d9a8ab713/nova/compute/manager.py#L3212

That happens before we spawn the instance which plugs VIFs and would also register it's own network-vif-plugged callback code:

https://github.com/openstack/nova/blob/a4e6340bdcc2fda8fed41abc64ea554d9a8ab713/nova/compute/manager.py#L3277

The same issue exists in finish_revert_resize:

https://github.com/openstack/nova/blob/a4e6340bdcc2fda8fed41abc64ea554d9a8ab713/nova/compute/manager.py#L4089

https://github.com/openstack/nova/blob/a4e6340bdcc2fda8fed41abc64ea554d9a8ab713/nova/compute/manager.py#L4108

Which was reported in a downstream Red Hat BZ: https://bugzilla.redhat.com/show_bug.cgi?id=1678681