在docker容器中运行Xephyr

Question

我试图在直接访问X11套接字的docker容器中运行嵌套的X-server Xephyr,但是我得到了奇怪的图形错误,我目前还不明白.

这些内容Dockerfile都是

FROM ubuntu:14.04

RUN apt-get update
RUN apt-get install -qqy xserver-xephyr

# Clean up APT when done.
RUN apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*

建立它与

sudo docker build -t xephyrtest .

并运行它

sudo docker run -e DISPLAY -v /tmp/.X11-unix:/tmp/.X11-unix xephyrtest Xephyr :1

输出以下内容:

Xephyr unable to use SHM XImages
Initializing built-in extension Generic Event Extension
Initializing built-in extension SHAPE
Initializing built-in extension MIT-SHM
Initializing built-in extension XInputExtension
Initializing built-in extension XTEST
Initializing built-in extension BIG-REQUESTS
Initializing built-in extension SYNC
Initializing built-in extension XKEYBOARD
Initializing built-in extension XC-MISC
Initializing built-in extension SECURITY
Initializing built-in extension XINERAMA
Initializing built-in extension XFIXES
Initializing built-in extension RENDER
Initializing built-in extension RANDR
Initializing built-in extension COMPOSITE
Initializing built-in extension DAMAGE
Initializing built-in extension MIT-SCREEN-SAVER
Initializing built-in extension DOUBLE-BUFFER
Initializing built-in extension RECORD
Initializing built-in extension DPMS
Initializing built-in extension Present
Initializing built-in extension DRI3
Initializing built-in extension X-Resource
Initializing built-in extension XVideo
Initializing built-in extension XVideo-MotionCompensation
Initializing built-in extension SELinux
Initializing built-in extension GLX
[dix] Could not init font path element /usr/share/fonts/X11/cyrillic, removing from list!
[dix] Could not init font path element /usr/share/fonts/X11/100dpi/:unscaled, removing from list!
[dix] Could not init font path element /usr/share/fonts/X11/75dpi/:unscaled, removing from list!
[dix] Could not init font path element /usr/share/fonts/X11/Type1, removing from list!
[dix] Could not init font path element /usr/share/fonts/X11/100dpi, removing from list!
[dix] Could not init font path element /usr/share/fonts/X11/75dpi, removing from list!

在这里,第一行Xephyr unable to use SHM XImages似乎是最重要的,因为它没有出现在Xephyr正常工作的主机上.

虽然Xephyr窗口弹出,但使用:1显示器的应用程序显示出奇怪的故障.例如,DISPLAY=:1 gedit这样(当鼠标在窗口内移动时,输出会迅速变化):

什么SHM XImages意思是什么,如何解决它在容器内的不可用性？

Answer 1

事实证明,自Docker 1.5使用命令以来,在Docker容器中运行Xephyr实际上非常容易

sudo docker run -e DISPLAY -v /tmp:/tmp --ipc=host --pid=host xephyrtest Xephyr :1

另外两个参数是

• --ipc=host 允许容器使用与主机相同的IPC名称空间,因此也可以访问相同的共享内存段
• --pid=host让容器查看(并修改)主机的进程.这是必要的,因为X服务器端口锁定是通过/tmp/.Xi-lock锁定文件(替换i为您的显示端口)完成的,其中包含在端口上运行的X服务器的pid i.

除了容器中的X11 unix套接字之外,您还必须更改-v /tmp/.X11-unix:/tmp/.X11-unix为-v /tmp:/tmp访问锁定文件.

虽然这很有效,但您必须注意,两个附加参数和对主机/tmp文件夹的访问权限授予容器重要权限,这在某些情况下可能会带来安全风险.