I've built just this for a client recently. There's one Ansible playbook that can be used to build a template for baking the AMI, and that same playbook can als

I've built just this for a client recently. There's one Ansible playbook that can be used to build a template for baking the AMI, and that same playbook can also be used to update a running instances on the fly, so you can update code without having to replace instances (which I strongly believe is better, and it's certainly faster than doing the instance cycling dance). Then there's a second playbook to bake the template into an AMI, update the launch configs and tell the autoscaling groups to use the new launch configs. For the latter two I had to write Ansible plugins (which the client might let me open source, once documented).