The dockerfile for the rails image. It's a standard ruby 2.5 docker image.
The rails application image
The MySQL database image
The rails (sidekiq) workers
Redis is used in Actioncable, in sidekiq workers or for the rails cache.
The Makefile is used mainly as a knowledge keeper for the project, and secondly to install the stack.
You should create a new rails application if you start from this repo. The current Makefile COPY the created Gemfile. So it's not currently suited to create the rails app in the docker image.
make rails_new
make up
The .dockerignore file lets you ignore certain folders or files from being included inside the docker container.