Accessing Ubuntu desktop from Mac Snow Leopard

Accessing my Ubuntu 9.04 Gnome desktop from the built in Mac OS X 10.6.2 VNC viewer took a bit of tweaking on the Ubuntu Gnome side. I have an OpenVPN SSL tunnel between the Mac and the Ubuntu desktop, however a SSH tunnel could also be used to protect the VNC session. In this post, I’ll just cover the VNC server setup assuming a secure connection between the Mac and the desktop.

Initially I followed the guidance at sanity, inc.”How to OS X Leopard Screen Sharing with Linux“, on Ubuntu I installed tightvnc:

apt-get install tightvncserver

Then tested it out by starting up the vnc server on the Ubuntu system as the user I want to run the remote session as:

tightvncserver -geometry 1024x700 -depth 24 :1

As tightvncserver starts up the VNC service, it will check for a .vncpasswd file in the user home directory. If it doesn’t exist, you will be prompted for a password to use to protect the remote session.  Note VNC is not designed to be used for multi-user remote access.
On the Mac, rather than use Bonjour to automatically discover the Ubuntu screen sharing service, I just referred to the VNC session directly within Finder which invokes the built in VNC viewer. Enter the VNC session password when prompted and the Ubuntu desktop is displayed. connect-to-server Within Finder, either use Go -> Connect to Server or Apple-K to bring up the Connect to Server window.  The server address is the URL that points to the Ubuntu VNC instance vnc:// where the port is 5900 + the display number specified when starting up the tightvncserver (5901).

This all worked fantastic, except for the keyboard mapping within Gnome – it was scrambled.  After googling several possible solutions, the only one that was successful for me was to disable the keyboard plugin in Gnome

Amit Gurdasani wrote on 2008-04-28: #51

I’ve also encountered this issue with TightVNC and the hardy release. My solution was to capture the xmodmap -pke output as ${HOME}/.Xmodmap at the login screen (DISPLAY=:0 XAUTHORITY=/var/lib/gdm/:0.Xauth sudo xmodmap -pke > ${HOME}/.Xmodmap). When gnome-settings-daemon starts up and finds an .Xmodmap, it asks if it should be loaded — I answer yes. As a side effect, if gnome-settings-daemon were to be restarted without the .Xmodmap, it’d scramble the keyboard layout again. With an .Xmodmap in place, it’ll load the .Xmodmap every time.

Due to another issue (#199245, gnome-settings-daemon crashing with BadWindow every time a window is mapped), I disabled the keyboard plugin using gconf-editor, at /apps/gnome_settings_daemon/plugins/keyboard. Since it’s not being loaded, I suspect it might not garble the layout even if I remove the .Xmodmap now.

So maybe disabling the keyboard plugin is a better fix.

On the Ubuntu system, invoke the Gnome configuration editor (gconf-editor on command line), then navigate to apps -> gnome_settings_daemon -> plugins -> keyboard uncheck the Active keyword.  Kill the VNC daemon and relaunch it – problem fixed.

pkill vnc
tightvncserver -geometry 1024x700 -depth 24 :1

Various methods exist to automatically start and kill the VNC server, but for now this will do it for me.