Simple docker-compose configuration for Rails

docker-compose.yml

version: '3'

services:
  postgres:
    container_name: my_rails_project_postgres
    image: postgres:11.5-alpine
    ports: ['5432:5432']
    environment:
      POSTGRES_USER: ${USER}
    volumes:
      - ./tmp/db:/var/lib/postgresql/data
    healthcheck:
      test: ['CMD', 'pg_isready', '-U', '${USER}']
      interval: 10s
      timeout: 5s
      retries: 5
  redis:
    container_name: my_rails_project_redis
    image: redis:5.0.6-alpine
    ports: ['6379:6379']
    healthcheck:
      test: ['CMD', 'redis-cli', 'ping']
      interval: 10s
      timeout: 5s
      retries: 5
  maildev:
    container_name: my_rails_project_maildev
    image: djfarrelly/maildev:latest
    ports:
      - '1080:80'
      - '1025:25'
    healthcheck:
      test: ['CMD', 'curl', '--fail', 'http://localhost']
      interval: 10s
      timeout: 5s
      retries: 5