It's clone of RHBZ targetted for 17.1 https://bugzilla.redhat.com/show_bug.cgi?id=2315341

Description of problem:
If the nameservers and domain name change in a network configuration, the host interface will be restarted so that the ifup script can change the nameserver. This needs to happen on the fly to enable adoption without disruption.

Version-Release number of selected component (if applicable):

18.0

How reproducible:
100%

Steps to Reproduce:

1. Have some workloads running on 17.1, run ping test to Nova VMs

2. Do adoption to 18.0

3. As part of adoption we require to update dns nameservers and domain name on edpm nodes, os-net-config recreates ovs bridges and this results into dataplane downtime.

Actual results:
The host interface or bridge which contains the name server setting are recreated

Expected results:
The nameservers are updated without restarting the interface.

Additional info: