在本土，这是不可能的。另请参阅此特性请求。

到目前为止，您需要在容器CMD中执行此操作，直到所有所需的服务都在那里。

在Dockerfiles CMD中，你可以引用你自己的启动脚本来启动你的容器服务。在你开始之前，你需要等待一个依赖的选项，比如:

Dockerfile

FROM python:2-onbuild
RUN ["pip", "install", "pika"]
ADD start.sh /start.sh
CMD ["/start.sh"]

start.sh

#!/bin/bash
while ! nc -z rabbitmq 5672; do sleep 3; done
python rabbit.py

也许你也需要在Dockerfile中安装netcat。我不知道python映像上预装了什么。

有一些工具提供了易于使用的等待逻辑，用于简单的tcp端口检查:

等待它 dockerize

对于更复杂的等待:

goss -解释博客

基于这篇博客文章https://8thlight.com/blog/dariusz-pasciak/2016/10/17/docker-compose-wait-for-dependencies.html

我配置了docker-compose。Yml如下所示:

version: "3.1"

services:
  rabbitmq:
    image: rabbitmq:3.7.2-management-alpine
    restart: always
    environment:
      RABBITMQ_HIPE_COMPILE: 1
      RABBITMQ_MANAGEMENT: 1
      RABBITMQ_VM_MEMORY_HIGH_WATERMARK: 0.2
      RABBITMQ_DEFAULT_USER: "rabbitmq"
      RABBITMQ_DEFAULT_PASS: "rabbitmq"
    ports:
      - "15672:15672"
      - "5672:5672"
    volumes:
      - data:/var/lib/rabbitmq:rw

  start_dependencies:
    image: alpine:latest
    links:
      - rabbitmq
    command: >
      /bin/sh -c "
        echo Waiting for rabbitmq service start...;
        while ! nc -z rabbitmq 5672;
        do
          sleep 1;
        done;
        echo Connected!;
      "

volumes:
  data: {}

然后执行for run =>:

Docker-compose start_dependencies

Rabbitmq服务将以daemon模式启动，start_dependencies将完成工作。

另一种解决方案是使用像Kubernetes这样的容器编排解决方案。Kubernetes支持init容器，它在其他容器启动之前运行到完成。你可以在这里找到一个SQL Server 2017 Linux容器的例子，其中API容器使用init容器初始化数据库

https://www.handsonarchitect.com/2018/08/understand-kubernetes-object-init.html

您还可以通过设置一个端点来解决这个问题，该端点使用netcat(使用docker-wait脚本)等待服务启动。我喜欢这种方法，因为在docker-compose中仍然有一个干净的命令部分。Yml，你不需要添加docker特定的代码到你的应用程序:

version: '2'
services:
  db:
    image: postgres
  django:
    build: .
    command: python manage.py runserver 0.0.0.0:8000
    entrypoint: ./docker-entrypoint.sh db 5432
    volumes:
      - .:/code
    ports:
      - "8000:8000"
    depends_on:
      - db

然后docker-entrypoint.sh:

#!/bin/sh

postgres_host=$1
postgres_port=$2
shift 2
cmd="$@"

# wait for the postgres docker to be running
while ! nc $postgres_host $postgres_port; do
  >&2 echo "Postgres is unavailable - sleeping"
  sleep 1
done

>&2 echo "Postgres is up - executing command"

# run the command
exec $cmd

这在官方docker文档中有记载。

PS:你应该在docker实例中安装netcat，如果这是不可用的。要做到这一点，请在Docker文件中添加以下内容:

RUN apt-get update && apt-get install netcat-openbsd -y 

I currently also have that requirement of waiting for some services to be up and running before others start. Also read the suggestions here and on some other places. But most of them require that the docker-compose.yml some how has to be changed a bit. So I started working on a solution which I consider to be an orchestration layer around docker-compose itself and I finally came up with a shell script which I called docker-compose-profile. It can wait for tcp connection to a certain container even if the service does not expose any port to the host directy. The trick I am using is to start another docker container inside the stack and from there I can (usually) connect to every service (as long no other network configuration is applied). There is also waiting method to watch out for a certain log message. Services can be grouped together to be started in a single step before another step will be triggered to start. You can also exclude some services without listing all other services to start (like a collection of available services minus some excluded services). This kind of configuration can be bundled to a profile. There is a yaml configuration file called dcp.yml which (for now) has to be placed aside your docker-compose.yml file.

对于你的问题，这看起来像:

command:
  aliases:
    upd:
      command: "up -d"
      description: |
        Create and start container. Detach afterword.

profiles:
  default:
    description: |
      Wait for rabbitmq before starting worker.
    command: upd
    steps:
      - label: only-rabbitmq
        only: [ rabbitmq ]
        wait:
          - 5@tcp://rabbitmq:5432
      - label: all-others

现在可以通过调用来启动堆栈

dcp -p default upd

或者仅仅通过

dcp

因为只有一个默认配置文件可以运行-d。

有个小问题。我目前的版本不支持特殊的等待条件，如ony 你实际上需要。这样就没有测试给兔子发信息了。

我已经在考虑进一步的等待方法，以在主机上或作为docker容器运行某个命令。 我们可以扩展这个工具，比如

...
        wait:
          - service: rabbitmq
            method: container
            timeout: 5
            image: python-test-rabbit
...

有一个名为python-test-rabbit的docker映像来进行检查。

这样做的好处是，你再也不需要把等待的部分交给你的员工了。 它将被隔离，并停留在业务流程层内。

也许有人会觉得这个有用。欢迎提出任何建议。

您可以在https://gitlab.com/michapoe/docker-compose-profile上找到这个工具

使用restart: unless-stopped或restart: always可以解决这个问题。

如果工作容器在rabbitMQ还没有准备好时停止，它将被重新启动，直到它准备好。