This is an example of how to achieve rolling deploys on AWS using Terraform. It is based on a strategy proposed by Paul Hinze - https://groups.google.com/forum/#!msg/terraform-tool/7Gdhv1OAc80/iNQ93riiLwAJ
terraform apply
browes to rolling_ELB_dns_name
terraform apply -var 'ami_id=ami-1234'
Tested on Terraform 0.7.11
MIT License