--- version: '3' services: db: image: postgres:latest volumes: - "db-data:/var/lib/postgresql/data" environment: POSTGRES_PASSWORD: mysecretpassword web: build: . command: bundle exec rails s -p 26906 -b 0.0.0.0 volumes: - .:/app - bundle-cache:/usr/local/bundle tmpfs: - /app/tmp/pids ports: - "26906:26906" depends_on: - db environment: DATABASE_URL: postgres://postgres:mysecretpassword@db:5432 volumes: db-data: bundle-cache: