Just to provide some more background info: for DMTF CIMI, I will be
pusing to standardize the EC2 approach, since it is the only one that
properly decouples the VM from the infrastructure; IOW, the standard
will hopefully mandate that each instance can access a web server at
http://169.254.169.254/ from which it can get the user data.
I trust you will also push to get an IPv6 address standarized,
probably something from the unique local address block: