bash 从 Docker 容器获取环境变量
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/34051747/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Get Environment Variable from Docker Container
提问by Citronen
What's the simplest way to get an environment variable from a docker container that has not been declared in the Dockerfile?
从未在 Dockerfile 中声明的 docker容器获取环境变量的最简单方法是什么？
For instance, an environment variable that has been set through some docker exec container /bin/bashsession?
例如，通过某个docker exec container /bin/bash会话设置的环境变量？
I can do docker exec container env | grep ENV_VAR, but I would prefer something that just returns the value.
我可以docker exec container env | grep ENV_VAR，但我更喜欢只返回值的东西。
I've tried using docker exec container echo "$ENV_VAR", but the substitution seems to happen outside of the container, so I don't get the env var from the container, but rather the env var from my own computer.
我试过使用docker exec container echo "$ENV_VAR"，但替换似乎发生在容器之外，所以我没有从容器中获取 env var，而是从我自己的计算机中获取 env var。
Thanks.
谢谢。
回答by jwodder
The proper way to run echo "$ENV_VAR"inside the container so that the variable substitution happens in the container is:
echo "$ENV_VAR"在容器内运行以便在容器中发生变量替换的正确方法是：
docker exec <container_id> bash -c 'echo "$ENV_VAR"'
回答by aisbaa
To view all env variables:
查看所有环境变量：
docker exec container env
To get one:
得到一个：
docker exec container env | grep VARIABLE | cut -d'=' -f2
回答by gentooboontoo
You can use printenv VARIABLEinstead of /bin/bash -c 'echo $VARIABLE. It's much simpler and it does not perform substitution:
您可以使用printenv VARIABLE代替/bin/bash -c 'echo $VARIABLE. 它更简单，并且不执行替换：
docker exec container printenv VARIABLE
回答by Sergiy Sokolenko
The downside of using docker execis that it requires a runningcontainer, so docker inspect -fmight be handy if you're unsure a container is running.
使用的缺点docker exec是它需要一个正在运行的容器，因此docker inspect -f如果您不确定容器是否正在运行，可能会很方便。
Example #1.Output a list of space-separated environment variables in the specified container:
示例#1。输出指定容器中以空格分隔的环境变量列表：
docker inspect -f \
'{{range $index, $value := .Config.Env}}{{$value}} {{end}}' container_name
the output will look like this:
输出将如下所示：
ENV_VAR1=value1 ENV_VAR2=value2 ENV_VAR3=value3
Example #2.Output each env var on new line and grepthe needed items, for example, the mysql container's settings could be retrieved like this:
示例#2。在新行上输出每个 env var 和grep所需的项目，例如，可以像这样检索 mysql 容器的设置：
docker inspect -f \
'{{range $index, $value := .Config.Env}}{{println $value}}{{end}}' \
container_name | grep MYSQL_
will output:
将输出：
MYSQL_PASSWORD=secret
MYSQL_ROOT_PASSWORD=supersecret
MYSQL_USER=demo
MYSQL_DATABASE=demodb
MYSQL_MAJOR=5.5
MYSQL_VERSION=5.5.52
Example #3.Let's modify the example above to get a bash friendlyoutput which can be directly used in your scripts:
示例#3。让我们修改上面的例子以获得一个bash 友好的输出，它可以直接在你的脚本中使用：
docker inspect -f \
'{{range $index, $value := .Config.Env}}export {{$value}}{{println}}{{end}}' \
container_name | grep MYSQL
will output:
将输出：
export MYSQL_PASSWORD=secret
export MYSQL_ROOT_PASSWORD=supersecret
export MYSQL_USER=demo
export MYSQL_DATABASE=demodb
export MYSQL_MAJOR=5.5
export MYSQL_VERSION=5.5.52
If you want to dive deeper, then go to Go's text/templatepackage documentation with all the details of the format.
如果您想更深入地研究，请访问 Go 的文本/模板包文档，其中包含格式的所有详细信息。
回答by sarink
None of the above answers show you how to extract a variable from a non-running container (if you use the echoapproach with run, you won't get any output).
上述答案都没有向您展示如何从非运行容器中提取变量（如果您使用echo方法run，您将不会得到任何输出）。
Simply runwith printenv, like so:
简单地run使用printenv，就像这样：
docker run --rm <container> printenv <MY_VAR>
(Note that docker-composeinstead of dockerworks too)
（请注意，docker-compose代替也docker有效）
回答by ddieppa
If by any chance you use VSCodeand has installed the docker extension, just right+clickon the docker you want to check (within the docker extension), clickon Inspect, and there search for env, you will find all your env variablesvalues
万一您使用VSCode并安装了泊坞窗延伸，只是right+click您要检查（该范围内的泊坞窗泊坞窗扩展），click对检查，并有搜索ENV，你会发现所有的ENV变量值
回答by Sathish
We can modify entrypointof a non-running container with the docker runcommand.
我们可以entrypoint使用docker run命令修改非运行容器。
Example show PATH environment variable:
示例显示 PATH 环境变量：
using
bashandecho: This answerclaims thatechowill not produce any output, which is incorrect.docker run --rm --entrypoint bash <container> -c 'echo "$PATH"'using
printenvdocker run --rm --entrypoint printenv <container> PATH
using
bashandecho：这个答案声称echo不会产生任何输出，这是不正确的。docker run --rm --entrypoint bash <container> -c 'echo "$PATH"'使用
printenvdocker run --rm --entrypoint printenv <container> PATH
回答by Citronen
@aisbaa's answer works if you don't care when the environment variable was declared. If you want the environment variable, even if it has been declared inside of an exec /bin/bashsession, use something like:
如果您不关心环境变量的声明时间，@aisbaa 的答案会起作用。如果您想要环境变量，即使它已在exec /bin/bash会话内声明，也可以使用以下内容：
IFS="=" read -a out <<< $(docker exec container /bin/bash -c "env | grep ENV_VAR" 2>&1)
It's not very pretty, but it gets the job done.
它不是很漂亮，但它完成了工作。
To then get the value, use:
要获取该值，请使用：
echo ${out[1]}
回答by MatteoOreficeIT
This command inspects docker stack processes' environment in the host :
此命令检查主机中 docker 堆栈进程的环境：
pidof dockerd containerd containerd-shim | tr ' ' '\n' \
| xargs -L1 -I{} -- sudo xargs -a '/proc/{}/environ' -L1 -0
