SSH key generation and bootstrap may happen on different hosts

[markgoddard]

Sometimes we see a bootstrap failure, where cephadm cannot read the previously generated SSH key. This seems to be because it generates the key on one host, then tries to bootstrap on another.

This seems to be some bug with run_once and delegate_to.

[markgoddard]

I think we may just need to set ansible_host similarly to how it's done in kayobe.

[markgoddard]

There is a second issue here - when using delegate_to, the task executes on the delegate host, but still sees the facts of the original host. This is a problem for the --mon-ip argument to cephadm bootstrap, which ends up with the wrong IP, and fails a bind check.