Split env file solutions

docker-compose.yml

version: '3.5'
services:
  # Php service configuration
  php:
    image: ${REGISTRY_PATH}/php:${TAG_PHP}
    networks:
      - default
      - database
    environment:
      MEMORY_LIMIT: "${MEMORY_LIMIT}"
      DB_HOST: "${DB_HOST}"
      DB_PORT: "${DB_PORT}"
      DB_NAME: "${DB_NAME}"
      DB_USER: "${DB_USER}"
      DB_PASSWORD: "${DB_PASSWORD}"
    deploy:
      replicas: ${REPLICA_COUNT_PHP:-1}
      resources:
        limits:
          memory: "${PHP_MEM_LIMIT:-1G}"

  # Nginx service configuration
  nginx:
    image: ${REGISTRY_PATH}/nginx:${TAG_NGINX}
    environment:
      HOSTNAME: "${HOSTNAME}"
    networks:
      - default
    ports:
      - ${HTTP_PORT}:80
    deploy:
      replicas: ${REPLICA_COUNT_NGINX:-1}
      resources:
        limits:
          memory: "${NGINX_MEM_LIMIT:-1G}"

networks:
  default:
  # The database network is external because used by many docker stacks
  database:
    external: true
    name: "${DATABASE_NETWORK}"