Comment 3 for bug 1821026

From Peng's latest reproduction this looks to be an issue with nova not being able to resolve the compute hostname.

As part of a live migration for a VM with a config-drive, nova on the destination worker node needs to scp the config-drive file from the source worker node. This is failing. See timeline below:

nfv-vim log:
2019-04-03T17:19:12.788 controller-1 VIM_Thread[126662] DEBUG _instance.py.1933 Live Migrate instance tenant2-config_drive-1.
2019-04-03T17:19:17.221 controller-1 VIM_Thread[126662] INFO _instance_director.py.908 Migrate of instance tenant2-config_drive-1 from host compute-0 failed.

nova-compute log from compute-0 (source worker):
{"log":"2019-04-03 17:19:17,025.025 43749 ERROR nova.compute.manager [-] [instance: 96e1cbf9-97d0-41af-a02a-f36da0e3fbcd] Pre live migration failed at compute-1: RemoteError: Remote error: ProcessExecutionError Unexpected error while running command.\n","stream":"stdout","time":"2019-04-03T17:19:17.028238913Z"}
{"log":"Command: scp -r compute-0:/var/lib/nova/instances/96e1cbf9-97d0-41af-a02a-f36da0e3fbcd/disk.config /var/lib/nova/instances/96e1cbf9-97d0-41af-a02a-f36da0e3fbcd\n"
...<snip>...
"ProcessExecutionError: Unexpected error while running command.\\nCommand: scp -r compute-0:/var/lib/nova/instances/96e1cbf9-97d0-41af-a02a-f36da0e3fbcd/disk.config /var/lib/nova/instances/96e1cbf9-97d0-41af-a02a-f36da0e3fbcd\\nExit code: 1\\nStdout: u''\\nStderr: u'ssh: Could not resolve hostname compute-0: Name or service not known\\\\r\\\\n'\\n\"].\n","stream":"stdout","time":"2019-04-03T17:19:17.028284159Z"}
#followed by a traceback