如何在所有用户启动容器时在Docker容器系统范围内设置环境变量？ [英] How to set environment variable in docker container system wide at container start for all users?

问题描述

我需要为docker容器内的所有用户和进程设置一些环境变量。应该在容器启动时设置它，而不要在 Dockerfile 中设置它，因为它取决于运行环境。

I need to set some environment variable for all users and processes inside docker container. It should be set at container start, not in Dockerfile, because it depends on running environment.

所以简单 Dockerfile

FROM ubuntu
RUN echo 'export TEST=test' >> '/root/.bashrc'

对于交互式会话非常有效
docker run -ti test bash
然后
env
并且有 TEST = test

works well for interactive sessions docker run -ti test bash then env and there is TEST=test

但是当 docker运行-ti test env 时，没有 TEST

我正在尝试

RUN echo 'export TEST=test' >> '/etc/environment'
RUN echo 'TEST="test"' >> '/etc/environment'
RUN echo 'export TEST=test' >> /etc/profile.d/1.sh
ENTRYPOINT export TEST=test

没有任何帮助

为什么我需要这个。我在由docker自动设置的容器内有 http_proxy 变量，我需要基于它设置另一个变量，即 JAVA_OPT ，请在整个系统范围内，对所有用户和进程以及在运行环境中（而不是在构建时）使用它。

Why I need this. I have http_proxy variable inside container automatically set by docker, I need to set another variables, based on it, i.e. JAVA_OPT, do it system wide, for all users and processes, and in running environment, not at build time.

推荐答案

一个将作为入口点的脚本：

I would create a script which would be an entrypoint:

#!/bin/bash

# if env variable is not set, set it
if [ -z $VAR ];
then
    # env variable is not set
    export VAR=$(a command that gives the var value);
fi

# pass the arguments received by the entrypoint.sh
# to /bin/bash with command (-c) option
/bin/bash -c $@ 

在Dockerfile中，我将设置入口点：

And in Dockerfile I would set the entrypoint:

ENTRYPOINT entrypoint.sh

现在每次我运行 docker run -it< image> <任何命令> 它使用我的脚本作为入口点，因此将始终在命令之前运行它，然后将参数传递到正确的位置，即 / bin / bash 。

Now every time I run docker run -it <image> <any command> it uses my script as entrypoint so will always run it before the command then pass the arguments to the right place which is /bin/bash.

如果您始终将入口点与参数，否则您的 $ @ 变量将为空，并给您一个错误 / bin / bash：-c：选项需要一个参数。一个简单的解决方法是使用if语句：

The above script is enough to work if you are always using the entrypoint with arguments, otherwise your $@ variable will be empty and will give you an error /bin/bash: -c: option requires an argument. A easy fix is an if statement:

if [ ! -z $@ ];
then
    /bin/bash -c $@;
fi

这篇关于如何在所有用户启动容器时在Docker容器系统范围内设置环境变量？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！