This is the Debian package repository of <%= @origin %>. It is used for internal distribution of locally built packages not yet part of Debian. Feel free to use it for yourself, but it comes at no warranty.
In your /etc/apt/sources.list:
deb http://debian.<%= scope.lookupvar('::domain') %>/debian squeeze main
deb-src http://debian.<%= scope.lookupvar('::domain') %>/debian squeeze main
"squeeze", of course, can be replaced by your distribution.
This archive self-signs packages uploaded to it (and packages uploaded are verified against a whitelist of trusted uploaders) using OpenPGP (GnuPG, to be more precise).
The key of the archive is in the key.asc file. You should add the key using something like this:
wget http://debian.<%= scope.lookupvar('::domain') %>/debian/key.asc
apt-key add key.asc
apt-get update