Running graphical applications remotely

Remote development often requires executing binaries that open graphical windows. Some of the most common examples are running ChromeOS on Linux and running any number of graphics-related tests. These binaries will immediately crash unless they are run against an X display, which is not the default case over SSH.

Using the remote desktop display

When Chrome Remote Desktop is installed it will create an X display, :20, which is what you see when you connect to your workstation or cloudtop. This display can be targeted by binaries run from the command line, even over SSH. For example:

DISPLAY=:20 ./out/Default/chrome

This will set the DISPLAY environment variable to :20 for the duration of the command, causing the chrome binary to run using :20 as the targeted display. This results in the ChromeOS window opening on the remote desktop display despite being run over SSH, or elsewhere.

Forwarding the display using xpra

Using the remote desktop display results in the ChromeOS window running inside the remote desktop window which itself is running within the browser. To avoid these nested windows and potentially reduce overall latency, you can allow your binaries to target a display on your MacBook. This is accomplished using the program xpra.

Install xpra on your MacBook via go/softwarecenter.

Install xpra on your workstation or cloudtop.

sudo apt-get install xpra

SSH to your workstation or cloudtop with port forwarding to allow xpra to forward the X11 window without hitting issues with gnubby.

ssh -L 5950:localhost:5950 <HOSTNAME>

Run xpra on your workstation or cloudtop and create a display xpra can forward to.

xpra start :50 --bind-tcp=127.0.0.1:5950

Attach xpra, on your MacBook, to the loopback address at the forwarded port.

xpra attach tcp://127.0.0.1:5950/

Run the graphical binary using the display created by xpra.

DISPLAY=:50 ./out/Default/chrome

Stop xpra when you are finished.

xpra stop :50

Note: Port-forwarding can introduce noticeable keystroke latency so it is recommended that you open a second connection solely for development.