Comment 1 for bug 1788447

In older release we used fab in which we had detach_vrouter task.

Detatach_vrouter does the following,
1. Stops Nova compute
2. Stops supervisor-vrouter
3. Exeecutes provision_vrouter.py with --del option and the IP details of the compute/api-server
Reference: https://github.com/Juniper/contrail-fabric-utils/blob/master/fabfile/tasks/misc.py#L47