bash 如何在每个“exec”命令中执行 Docker 镜像的入口点？
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How to execute the Entrypoint of a Docker images at each "exec" command?
提问by Doubidou
After trying to test Dockerfiles with Dockerspec, I finally had an issueI can't resolve properly.
在尝试使用 Dockerspec 测试 Dockerfiles 后，我终于遇到了一个无法正确解决的问题。
The problem is, I think, from Docker itself ; If I understand its process, an Entrypoint is only executed at run, but if the container stay started and I launch an "exec" command in, it's not re-called.
我认为问题出在 Docker 本身；如果我了解它的过程，一个 Entrypoint 只会在 run 时执行，但是如果容器保持启动状态并且我在其中启动了一个“exec”命令，它就不会被重新调用。
I think it's the wanted behavior.
我认为这是想要的行为。
But if the Entrypoint is a "gosu" script which precede all my commands, it's a problem...
但是，如果入口点是“古薮”脚本，我之前所有的命令，这是个问题......
Example
例子
"myImage" has this Entrypoint :
gosu 1000:1000 "$@"
“myImage”有这个入口点：
gosu 1000:1000 "$@"
If I launch : docker run -it myImage id -u
如果我启动： docker run -it myImage id -u
The output is "1000".
输出为“1000”。
If I start a container : docker run -it myImage bash
如果我启动一个容器： docker run -it myImage bash
In this container, id -uoutputs "1000".
在这个容器中，id -u输出“1000”。
But if I start a new command in this container, it starts a new shell, and does not execute the Entrypoint, so : docker exec CONTAINER_ID id -u
但是如果我在这个容器中启动一个新命令，它会启动一个新的 shell，并且不执行 Entrypoint，所以： docker exec CONTAINER_ID id -u
Output "0", because the new shell is started as "root".
输出“0”，因为新 shell 以“root”身份启动。
It there a way to execute each time the entrypoint ? Or re-use the shell open ?
有没有办法在每次进入入口点时执行？还是重新用shell打开？
Or a better way to do that ?
或者有更好的方法来做到这一点？
Or, maybe I haven't understand anything ? ;)
或者，也许我什么都不明白？;)
Thanks !
谢谢 ！
EDIT
编辑
After reading solutions proposed here, I understand that the problem is not how Docker works but how Serverspec works with ; my goal is to directly test a command as a docker runargument, but Serverspec start a container and test commands with docker exec.
在阅读了此处提出的解决方案后，我明白问题不在于 Docker 的工作方式，而在于 Serverspec 的工作方式；我的目标是直接将命令作为docker run参数进行测试，但 Serverspec 启动一个容器并使用docker exec.
So, the best solution is to found how get the stdout of the docker runexecuted by Serverspec.
因此，最好的解决方案是找到如何获取docker runServerspec 执行的标准输出。
But, in my personal use-case, the best solution is maybe to not use Gosu but --user flag :)
但是，在我个人的用例中，最好的解决方案可能是不使用 Gosu 而是 --user 标志:)
采纳答案by Derick Bailey
if your goal is to run the docker execwith a specific user inside of the container, you can use the --useroption.
如果您的目标是docker exec在容器内与特定用户一起运行，则可以使用该--user选项。
docker exec --user myuser container-name [... your command here]
docker exec --user myuser container-name [... your command here]
If you want to run gosuevery time, you can specify that as the command with docker exec
如果你想gosu每次都运行，你可以将它指定为命令docker exec
docke exec container-name gosu 1000:1000 [your actual command here]
docke exec container-name gosu 1000:1000 [your actual command here]
in my experience, the best way to encapsulate this into something easily re-usable is with a .sh script (or .cmd file in windows).
根据我的经验，将其封装为易于重用的最佳方法是使用 .sh 脚本（或 Windows 中的 .cmd 文件）。
drop this into a file in your local folder... maybe gsfor example.
将其放入本地文件夹中的文件中......也许gs例如。
#! /bin/sh
docker exec container-name gosu 1000:1000 "$@"give it execute permissions with chmod +x gsand then run it with ./gsfrom the local folder
给它执行权限，chmod +x gs然后./gs从本地文件夹运行它
