We do something similar for our apps on ec2. We use userdata to configure our ami, which then connects to our puppetmaster with the node details and everything happens like magic (ssl certs, web adresses, databases, web apps, security, users etc).

This feature is really underutilized. I render these bootscripts on the fly with ERB to bootstrap clusters on EC2 with a few config vars, the script then determines node type at boot from the security group then pulls full source code from github, which handles mounting drives, NFS, etc.