As an aside from EC2, it's worth mentioning that Foreman tries to connect to the public IP of the instance for the moment (to SSH in and run the finish script) so you _must_ select a floating IP group for the new instance - if you leave at none it will fail to build correctly.

It's something I'd like to fix (especially if Foreman is on your Openstack cloud and thus has access to the internal IPs) but we've not got there yet.