Broadway is a display server for using GTK+ applications in a web browser like Chrome or Firefox. It is based on HTML5 and WebSockets. GTK (originally GIMP Toolkit) is a GUI toolkit used by many Linux desktop applications like Darktable, Gimp and RawTherapee. Obviously this technology is ideal for editing images in the browser, at least when the connection is fast enough.
# Configure broadwayd (HTML5 display server) RUN apt-get update && apt-get install libgtk-3-bin ENV GDK_BACKEND broadway ENV BROADWAY_DISPLAY :5 EXPOSE 8080 CMD broadwayd -p 8080 -a 0.0.0.0 :5
When this is configured, all you need to do is open http://localhost:8080 in a browser and start any GTK application in the same container (broadwayd must be running). It should be displayed instantly, otherwise the screen is white, but you shouldn't see an error.