http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/AESDG-chapter-instancedata.html

Common problem with finding the public IP of the machine:

• http://169.254.169.254/latest/meta-data/public-ipv4 is empty although VMs have public IPs
• http://169.254.169.254/latest/meta-data/local-ipv4 contains the public IP

Also, it should be strongly recommended that each OpenStack cloud change the default .novalocal suffix to something site-specific.

EC2 meta-data should return the hostname for private IPs, not the ip address in the hostname field. in nova.conf

ec2_private_dns_show_ip=false