nova-status should be used during deployment and upgrades

[Lee Yarwood]

Description
===========
As discussed at various PTGs, summits and on the ML [1] Nova now provides a `nova-status upgrade check` command [2] for use during an upgrade to ensure everything is ready before services are restarted. This command also works during initial deployments and so is something we could easily plug into the current TripleO upgrade and ffwd upgrade flows.

[1] http://lists.openstack.org/pipermail/openstack-dev/2018-June/131459.html
[2] https://docs.openstack.org/nova/latest/cli/nova-status.html

[Juan Antonio Osorio Robles (juan-osorio-robles)]

Is this being worked on?

[Lee Yarwood (lyarwood)]

Yes, I was waiting for https://review.rdoproject.org/r/#/c/18735/ to get promoted, I'll respin today and get things listed in here correctly.