I thought this was going to be about the warm glow you get when you realise that the hot new framework/library/methodology you haven't got round to investigating yet, is already on the way out.
You should check out what docker and kubernetes actually are if you'd like to discuss them. Kubernetes is a management engine that controls docker containers, replacing the docker developed solution.
user_request -> kubernetes api -> docker api on a host
You can drop in other runtimes, like using containerd directly.