Tip: netinstall with apt-cacher

["John S. Skogtvedt" <jss@bzz.no>]

For those who don't know, apt-cacher is an APT proxy, e.g. a HTTP proxy
intended for Debian packages.
It is one of n APT proxies in the archive, but benefits include being
easy to set up, the ability to be used as a proxy (rather than having to
specify it as a mirror) and having the possibility to import packages
from a previously installed system.

1)
Install apt-cacher, i.e. aptitude install apt-cacher

2)
Configure apt-cacher, unless you have an upstream HTTP proxy or you want
to restrict access to apt-cacher, you only need to make the following
change to /etc/apt-cacher/apt-cacher.conf:

Find the index_files_regexp line, uncomment it and add |\.key|\.msg
before the closing parenthesis, e.g.:
index_files_regexp = (?:Index|Packages\.gz| ...
|Translation-.+\.bz2|\.key|\.msg)$

This is necessary because the installer downloads a .key and a .msg file
using the proxy. Apt-cacher is only intended to be used as an APT proxy,
and so rejects non-APT URLs.

3)
Boot the netinstall CD. Choose the menu option you want, but don't press
enter; instead press TAB and then add the text
"mirror/http/proxy=http://10.0.2.2:3142/"; to the kernel command line.
Now press enter.
The installer will boot and use your apt-cacher proxy.

Substitute 10.0.2.2 for the IP of your apt-cacher proxy.