An Amazon Resource Name (ARN) uniquely identifies a thing in AWS. This is a quick recap on how they are structured.
I like Ansible, but it has flaws. I'm going to assume you know what Ansible is, and that you have used it before.
Basic Ansible is amazing, compared to the alternatives. When the alternative is half-baked bash scripts that rely on special environmental state, and obscure notation that is used infrequently, it is not hard to better it. I've used other automation tools too. Puppet is the other automation tooling that I've spent considerable time with. Puppet and I did not agree with each other as it required me to learn hundreds of special syntax rules almost immediately.