Comment 4 for bug 1468871

While you could achieve what you want using a single nova-compute service using finer-grained placement rules, I think this is still a valid request since there are valid reasons to use separate services for different compute AZs (e.g. if you wanted each AZ to have its own set of Ceph credentials) and SSH keys for all compute units will need to be shared across services in order for cross-AZ migration to be possible.