axl:~/github/senseless-app (master) $ cat .dockerignore
.git
.gitignore
axl:~/github/senseless-app (master) $ cat Dockerfile
FROM rails:onbuild

RUN echo 'hello World'
axl:~/github/senseless-app (master) $ cat docker-compose.yml
db:
  image: mysql:latest
  environment:
    MYSQL_ROOT_PASSWORD: root
web:
  build: .
  volumes:
    - .:/usr/src/app
  ports:
    - "3001:3000"
  links:
    - db