So I see a lot of guides like this (I have one myself), but none that are built on top of Chef-solo/Ansible/Knife. Which makes me wonder, which is the correct

So I see a lot of guides like this (I have one myself), but none that are built on top of Chef-solo/Ansible/Knife. Which makes me wonder, which is the correct way which lends itself to automation and doesn't depend on AWS/AMI?