Ssh – Access GUI of an already running application through SSH

gnu-screensshx11

I have a virtual server, and a graphic application (an electron browser, actually) is running on it.

I actually run the command launching it with this script:

#!/usr/bin/env bash
set -e

# Start Xvfb
Xvfb -ac -screen scrn 1280x800x24 :9.0 &
export DISPLAY=:9.0

exec "$@"

It's running even while I'm not connected to ssh, in a screen. However sometimes when connecting to the server I want to access its GUI. It's different from launching it directly with ssh -X. Is there any way to access the display created by Xfvb?

Best Answer

You can start a VNC server on an existing X server by using x11vnc. However, if you anticipate the need to do this, you may want to use Xvnc instead of Xvfb.

Linux workstation

Perversely, many versions of GDM don't offer a way to pass arguments like +iglx to Xorg. In response, new X.org versions have an IndirectGLX option (see also example xorg.conf text).

In the absence of that option, there is a workaround of wrapping Xorg itself with a shell script:

mv /usr/bin/Xorg /usr/bin/Xorg.original
echo -e '#!/usr/bin/env bash\nexec /usr/bin/Xorg.original "$@" +iglx' > /usr/bin/Xorg
chmod +x /usr/bin/Xorg
chcon --type=bin_t /usr/bin/Xorg

macOS workstation (XQuartz)

Just run

defaults write org.macosforge.xquartz.X11 enable_iglx -bool true

and restart XQuartz if it's running. (Beware of typos: there is no error checking on the domain and variable names.)

Best Answer

Related Solutions

Xvfb and Firefox – Troubleshooting Errors and Logging Issues

Ssh – X Forwarding with indirect rendering fails with newer clients

Linux workstation

macOS workstation (XQuartz)

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