ec2_templater

https://github.com/reinteractive/ec2_templater

Ec2Templater provides a means of EC2 service discovery by templating your server config. It works by periodically querying AWS for the list of running EC2 instances, rendering a template, then running a notify command if it has changed. Using this setup you can provide, for example, a haproxy config that updates based on instances that are available filtered by tag