Deploying it was still always a hassle and involved searching for existing Dockerfiles and blog posts to cobble together a working one. At the beginning I always thought I'm doing something wrong as it's supposed to be easy and do everything nicely out of the box.

And dhh apparently agrees (Now at least: https://dhh.dk/posts/30-myth-1-rails-is-hard-to-deploy) as there's now a default Dockerfile and also this project he's working on, this will make things a lot nicer and more polished: https://github.com/rails/mrsk