ansible/ansible — pull request #2421 by robparrott (2013-03-16 03:01:28+00:00)
Title: Make ec2 module idempotent with Amazon EC2 via client-token attribute.

This allows one to rerun ansible playbooks that startup EC2 instances over and over without starting new isntances each time.

Uses new optional "id=" variable to set the "client-token" attribute on the request. Due to limiataions in the EC2 API, this means that the instance count can't change unless the id changes as well.