使用Dockerfile的主机环境变量 [英] Using host environment variables with Dockerfile

问题描述

我正在尝试使用卷共享在Docker guest虚拟机中共享文件。为了获得相同的UID，因此与这些文件的互操作性，我想在Docker的客人中创建与我自己的用户相同的UID的用户。

为了测试这个想法，我写了以下简单的Dockerfile：

  FROM phusion / baseimage 
 
 RUN touch / root / uid- $ UID 
  

使用 docker build -t = docktest。然后 docker run docktest ls -al / root 显示文件简单地命名为 uid- 。

在访客构建过程中有没有办法与Docker共享主机环境变量？

解决方案

环境不共享，您可以使用-e，--env选项在容器中设置env变量。

我通常使用这种方法，当我想拥有相同的所有者的映射卷：我检查uid& gid容器中的目录，然后创建一个对应的用户。在这里我的脚本（setuser.sh）为目录创建一个用户：

 ＃！/ bin / bash 
 
 setuser（）{
 if [-z$ 1];那么
 echo用法：$ 0< path> 
 return 
 fi 
 CURRENT_UID =`id -u` 
 DEST_UID =`stat -c％u$ 1` 
如果[$ CURRENT_UID = $ DEST_UID];然后
 return 
 fi 
 DEST_GID =`stat -c％g$ 1`
如果[-e / home / $ DEST_UID];然后
返回
 fi 
 groupadd -g $ DEST_GID $ DEST_GID 
 useradd -u $ DEST_UID -g $ DEST_GID $ DEST_UID 
 mkdir -p / home / $ DEST_UID 
 chown $ DEST_UID：$ DEST_GID / home / $ DEST_UID 
} 
 setuser $ 1 
  

这是作为用户运行命令的包装器脚本，其中具有权限的目录指定为$ USER_DIR或/ etc / user_dir

 ＃！/ bin / bash 
如果[-z$ USER_DIR];然后
如果[-e / etc / user_dir];那么
 export USER_DIR =`head -n 1 / etc / user_dir` 
 fi 
 fi 
如果[-n$ USER_DIR];那么
如果[！ -d$ USER_DIR];然后
 echo请在运行此脚本之前挂载$ USER_DIR
 exit 1 
 fi 
。 `dirname $ BASH_SOURCE` / setuser.sh $ USER_DIR 
 fi 
如果[-n$ USER_DIR];然后
 cd $ USER_DIR 
 fi 
如果[-e / etc / user_script];那么
。 / etc / user_script 
 fi 
如果[$ CURRENT_UID = $ DEST_UID];然后
$ @
 else 
 su $ DEST_UID -p -c$ @
 fi 
  

I'm trying to share files within a Docker guest using the volume sharing. In order to get the same UID, and therefore interoperability with those files, I would like to create a user in the Docker guest with the same UID as my own user.

In order to test out the idea, I wrote the following simplistic Dockerfile:

FROM phusion/baseimage

RUN touch /root/uid-$UID

Testing it with docker build -t=docktest . and then docker run docktest ls -al /root reveals that the file is simply named uid-.

Is there a means to share host environment variables with Docker during the guest build process?

解决方案

The environment is not shared, you could use -e, --env options to set env variables in container.

I usually use this approach when I want to have the same owner of the mapped volume: I check uid & gid of directory in container and then create a corresponding user. Here my script (setuser.sh) which creates a user for a directory:

#!/bin/bash

setuser() {
  if [ -z "$1" ]; then
    echo "Usage: $0 <path>"
    return
  fi
  CURRENT_UID=`id -u`
  DEST_UID=`stat -c "%u" $1`
  if [ $CURRENT_UID = $DEST_UID ]; then
    return
  fi
  DEST_GID=`stat -c "%g" $1`
  if [ -e /home/$DEST_UID ]; then
    return
  fi
  groupadd -g $DEST_GID $DEST_GID
  useradd -u $DEST_UID -g $DEST_GID $DEST_UID
  mkdir -p /home/$DEST_UID
  chown $DEST_UID:$DEST_GID /home/$DEST_UID
}
setuser $1

And this is the wrapper script which runs commands as the user, where the directory with permissions is specified either as $USER_DIR or in /etc/user_dir

#!/bin/bash
if [ -z "$USER_DIR" ]; then
  if [ -e /etc/user_dir ]; then
    export USER_DIR=`head -n 1 /etc/user_dir`
  fi
fi
if [ -n "$USER_DIR" ]; then
  if [ ! -d "$USER_DIR" ]; then
    echo "Please mount $USER_DIR before running this script"
    exit 1
  fi
  . `dirname $BASH_SOURCE`/setuser.sh $USER_DIR
fi
if [ -n "$USER_DIR" ]; then
  cd $USER_DIR
fi
if [ -e /etc/user_script ]; then
  . /etc/user_script
fi
if [ $CURRENT_UID = $DEST_UID ]; then
  "$@"
else
  su $DEST_UID -p -c "$@"
fi

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