version: '3' services: web: build: . command: ruby bin/rails s -p 3000 -b '0.0.0.0' volumes: - .:/app links: - postgres ports: - "3000:3000" expose: - "3000" postgres: image: postgres:10.4 environment: POSTGRES_USER: postgres POSTGRES_PASSWORD: postgres volumes: - ".:/app" ports: - "5432:5432" expose: - "5432" volumes: postgres: