Comment 3 for bug 2054348

I agree there are some corner cases where our use of delegate_to does not always work. I think the fix may vary, depending on the context, but here are some options/ideas:

- find an intersection of nova-api group and ansible_play_hosts, so that we always delegate to an active host
- fail early if we don't have the necessary hosts for the operation

In this specific case, perhaps performing the 'fail' task using delegate_to and run_once would bring the registered variable into scope?