[xen-tools-discuss] debootstrap and apt-cacher-ng

New to list, apologies if this has been asked before but I couldn't find a
searchable archive of the mailing list, and this wasn't in the FAQs.

We have a server running apt-cacher-ng on our LAN. When we build a new xen
image with xen-create-image, is there a way to specify that the apt-proxy
should be set to our apt-cacher-ng address? Once the system is built, we
can put 

	Acquire::http::Proxy "http://10.0.0.1:3142/";

in /etc/apt/apt.conf, but it would be nice to be able to use 
apt-cacher-ng for the initial debootstrap build too.

Thanks.