With Ubuntu, the keymap, console font etc. are setup by the console-setup package. However, simply adding something like
console-setup console-setup/variant select Germany - Eliminate dead keys console-setup console-setup/charmap select UTF-8 console-setup console-setup/compose select No compose key console-setup console-setup/fontsize-text select 16 console-setup console-setup/layout select Germany console-setup console-setup/altgr select Right Alt console-setup console-setup/model select Generic 105-key (Intl) PC console-setup console-setup/codeset select # Latin1 and Latin5 - western Europe and Turkic languages console-setup console-setup/fontface select VGA
to debconf/CLASS won't work, you will get the defaults (US keyboard layout etc.) instead. Simply running dpkg-reconfigure console-setup will even overwrite your debconf database! The solution is to run a script such as the following:
rm -f $target/etc/default/console-setup rm -f $target/etc/console/boottime.kmap.gz $ROOTCMD dpkg-reconfigure console-setup
Once this file is out of the way, dpkg-reconfigure will regenerate it from the values in the debconf database.
(Tested on Ubuntu Hardy.)