使用dockerrun命令将参数传递给Dockerfile中的CMD-UsedockerruncommandtopassargumentstoCMDinDockerfile

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Make sure your Dockerfile declares an environment variable with ENV:

确保Dockerfile使用ENV声明了一个环境变量:

ENV environment default_env_value
ENV cluster default_cluster_value

The ENV form can be replaced inline.

ENV 表单可以内联替换。

Then you can pass an environment variable with docker run

然后，您可以通过docker run传递环境变量。

docker run -p 9000:9000 -e envirOnment=dev -e cluster=0 -d me/app

Or you can set them through your compose file:

或者你可以通过你的撰写文件来设置它们:

node:
  environment:
    - envirOnment=dev
    - cluster=0

Your Dockerfile CMD can use that environment variable, but, as mentioned in issue 5509, you need to do so in a sh -c form:

您的Dockerfile CMD可以使用该环境变量，但是，正如第5509号问题所提到的，您需要以sh -c形式这样做:

CMD ["sh", "-c", "node server.js ${cluster} ${environment}"]

The explanation is that the shell is responsible for expanding environment variables, not Docker. When you use the JSON syntax, you're explicitly requesting that your command bypass the shell and be executed directly.

解释是shell负责扩展环境变量，而不是Docker。当您使用JSON语法时，您显式地请求您的命令绕过shell并直接执行。

Same idea with Builder RUN (applies to CMD as well):

Builder RUN也有同样的想法(同样适用于CMD):

Unlike the shell form, the exec form does not invoke a command shell.
This means that normal shell processing does not happen.

与shell表单不同，exec表单不调用命令shell。这意味着正常的shell处理不会发生。

For example, RUN [ "echo", "$HOME" ] will not do variable substitution on $HOME. If you want shell processing then either use the shell form or execute a shell directly, for example: RUN [ "sh", "-c", "echo $HOME" ].

例如，RUN ["echo"， "$HOME"]不会对$HOME进行变量替换。如果您想要shell处理，那么可以使用shell表单或直接执行shell，例如:RUN ["sh"， "-c"， "echo $HOME"]。

When using the exec form and executing a shell directly, as in the case for the shell form, it is the shell that is doing the environment variable expansion, not docker.

当使用exec形式并直接执行shell时，就像在shell表单中一样，它是环境变量扩展的shell，而不是docker。

12  

Another option is to use ENTRYPOINT to specify that node is the executable to run and CMD to provide the arguments. The docs have an example in Exec form ENTRYPOINT example.

另一种选择是使用ENTRYPOINT指定该节点是运行的可执行文件和CMD来提供参数。文档在Exec表单入口点示例中有一个示例。

Using this approach, your Dockerfile will look something like

使用这种方法，您的Dockerfile将看起来像这样

FROM ...

ENTRYPOINT [ "node",  "server.js" ]
CMD [ "0", "dev" ]

Running it in dev would use the same command

在dev中运行它将使用相同的命令

docker run -p 9000:9000 -d me/app

and running it in prod you would pass the parameters to the run command

在prod中运行时，将参数传递给run命令

docker run -p 9000:9000 -d me/app 1 prod

You may want to omit CMD entirely and always pass in 0 dev or 1 prod as arguments to the run command. That way you don't accidentally start a prod container in dev or a dev container in prod.

您可能希望完全省略CMD，并始终将0 dev或1 prod作为run命令的参数传递给它。这样，您就不会意外地在dev中启动一个prod容器，或者在prod中启动一个dev容器。

4  

The typical way to do this in Docker containers is to pass in environment variables:

在Docker容器中这样做的典型方法是传入环境变量:

docker run -p 9000:9000 -e NODE_ENV=dev -e CLUSTER=0 -d me/app