To build the container and all its dependencies run
docker-compose build
Then setup the database:
docker-compose run --rm app rake db:drop && rake db:create && rake db:migrate && rake db:seed
If everything went fine you should be able to run
docker-compose up
You can find the swagger docs on http://localhost:3000/swagger_doc Put the URL into some REST client like insomnia or browse it via Swagger UI