dockerheadlesspyvirtualdisplay

Docker and X server: Cannot establish any listening sockets

So I have the following script that I'm running in a Docker container:

#!/bin/bash

# silencing matplotlib warning
MPLCONFIGDIR="/tmp"
export MPLCONFIGDIR

# Virtual display
export DISPLAY=:0
Xvfb :0 -screen 0 1024x768x24

# my python module is called at this point

The first time I run the script, there seems to be a process that gets stuck: I don't know what's happening behind the terminal, I just have a blank line waiting forever. If I do ctrl+x the process seems to exit and the rest of the script (my python module) is executed just fine.

The second time I run the same script, I get the following error:

_XSERVTransSocketUNIXCreateListener: ...SocketCreateListener() failed
_XSERVTransMakeAllCOTSServerListeners: server already running
(EE) 
Fatal server error:
(EE) Cannot establish any listening sockets - Make sure an X server isn't already running(EE)

Then everything seems to run fine, but I would like to get rid of this warning/error and this weird ctrl+x. Any idea how to proceed?

Solution

  • The issues is that Xvfb :0 -screen 0 1024x768x24 is a blocking command.

    To run a blocking command in the background, append & to the end of the command: Xvfb :0 -screen 0 1024x768x24 &

    This will run the command in the background without blocking the execution of the rest of your script.