Docker：容器 state 出口 0

Question

我对 docker 容器有疑问。 那是我的 docker-compose 文件，包含 5 个服务

    version: '3'
networks:
  laravel:

services:

  nginx:
    image: nginx:stable-alpine
    container_name: nginx
    ports: 
      - "8088:80"
    volumes: 
      - ./src:/var/www/html 
      - ./nginx/default.conf:/etc/nginx/conf.d/default.conf
    depends_on: 
    - mysql
    - php

    networks: 
    - laravel

  mysql:
    image: mysql:5.7.22
    container_name: mysql
    restart: unless-stopped
    tty: true
    ports: 
      - "4306:3306"
    environment: 
      MYSQL_DATABASE: homestead
      MYSQL_USER: homestead
      MYSQL_PASSWORD: secret
      MYSQL_ROOT_PASSWORD: secret
      SERVICE_TAGS: dev
      SERVICE_NAME: mysql

    networks: 
    - laravel

  php:
    build: 
      context: .
      dockerfile: Dockerfile
    container_name: php
    volumes: 
      - ./src:/var/www/html
    ports:
      - "9000:9000"
    networks: 
      - laravel

  redis:
        image: redis:5.0.0-alpine
        restart: always
        container_name: redis
        ports:
            - "6379:6379"
        networks:
          - laravel
  composer:
    image: composer:latest
    container_name: composer
    volumes:
      - ./src:/var/www/html
    tty: true
    working_dir: /var/www/html
    networks:
      - laravel

然后我跑

docker-compose 向上 -d

接着

docker-compose ps

看到我的容器，我总是用代码 0 来获取作曲家容器。这就是屏幕截图

：

有人能解释一下为什么我不能把这个容器放上去吗？ 非常感谢

Answer 1

composer不是一个可以存活的程序。 这是一个执行特定工作然后退出的程序。

There's not much purpose in keeping it "up", since it's not going to do anything like the other processes do (nginx intercepts web traffic and writes response, mysql accepts database connections and reads/writes from a database, php serves web content, redis可以作为缓存连接）。