Linux Server Hacks, Volume Two

Hack #13. Autostart VNC Servers on Demand

Eliminate the need to manually start VNC servers on remote machines.

In this age of enlightenment and whizzy graphical devices, most Unix servers have graphical consoles instead of the VT100s or LA123s of days gone by. This is certainly true of most Linux servers, though most machine rooms save space by installing a single monitor and using a KVM to switch between the systems that are actually using it at the moment. As explained in "Access Systems Remotely with VNC" [Hack #10] , the traditional mode of operation for VNC is to SSH/telnet/whatever to a remote system, manually start a VNC server, and then nip back to the system you're actually using and start the VNC viewer there. It's easy enough—but isn't the whole "SSH there, stand on one leg, start this, pop back here, start that here" business irritating?

This hack explains how to avoid all that by integrating the VNC X Window System server directly into your graphical X Window System login environment. The basic idea is that you configure your machine to use your system's Internet daemon ( xinetd or inetd) to start the Xvnc server whenever an incoming VNC connection is sensed on one or more ports. You also configure your system to use the X Display Manager Control Protocol (XDMCP) to manage any new X displays, such as the Xvnc server. When the Xvnc server starts in response to an incoming port request, it displays an XDMCP login screen, you log in, and voilà!

Integrating Xvnc with inetd ...