[bradwood]

Go have a look at Gitlab's "Review Apps" -- this provides a mechanism that spins up branch-specific environments, and destroys them when the branch merges -- which sounds like what you are after. This is not so much about Docker (per se) but more about how to set up CI/CD related infrastructure.

We use this mechanism with AWS, the serverless framework and some terraform. It works well. With us, the only thing remotely container related is the runtime context for the CI/CD pipeline.

That being said, you could make this work against a k8s cluster, fargate, or just some build servers.