Locking Down the Ubuntu Log-In Screen

One of the requirements I have for a kiosk project is to use a timed login instead of an automatic log in when the server boots. This is required so that some special drivers for the touchscreen have time to load and also gives an admin time to log-in using their profile if need be.

When the computer boots the Ubuntu login screen is displayed for 10 seconds before the limited user account is automatically logged in and the kiosk application is automatically launched.

The problem with this process is that during this 10 second window someone could change the login session from the default ( I normally use blackbox ) to something else by using the little "options" button in the bottom left corner. ( or at least it's in the bottom left corner of the default Ubuntu login theme 'human' ).

If you want to lock down or even just customize the login screen to suit your needs an easy way to do this is to edit the XML file which defines and places the elements on the login window. You can edit the main file for the default human theme with gedit.

cd /usr/share/gdm/themes/Human
sudo cp Human.xml Human.xml.backup
sudo gedit Human.xml

In my file I just commented out the <item> element which defined the option button. Voila ! No more option button.