By default yes but you can change a single environment variable to not run Postgres or Redis through Docker Compose. You can also very easily choose to run Puma and Sidekiq on different servers. It leverages Docker Compose v2 profiles.
It's a full end to end walk through of the example Rails app and how it all works when it comes to Docker and Docker Compose. I just recorded it a month ago, it covers everything with up to date info vs the code in the repo.
I'd suggest watching and reading: https://nickjanetakis.com/blog/a-guide-for-running-rails-in-...
It's a full end to end walk through of the example Rails app and how it all works when it comes to Docker and Docker Compose. I just recorded it a month ago, it covers everything with up to date info vs the code in the repo.