Overview
========

This module manages apt on Debian.

It keeps dpkg's and apt's databases as well as the keyrings for securing
package download current.

backports.org is added and an archive key is provided[1].

dselect is switched to expert mode to suppress superfluous help screens.

sources.list and apt_preferences are managed. Testing and unstable are pinned to
very low values by default to prevent accidental upgrades.

This module needs lsb-release installed.


Variables
=========

$apt_clean: Sets DSelect::Clean, defaults to 'auto' on normal hosts and
	'pre-auto' in vservers, since the latter are usually more space-bound and
	have better recovery mechanisms via the host
	From apt.conf(5), 0.7.2: "Cache Clean mode; this value may be one of
		always, prompt, auto, pre-auto and never. always and prompt will
		remove all packages from the cache after upgrading, prompt (the
		default) does so conditionally.  auto removes only those
		packages which are no longer downloadable (replaced with a new
		version for instance). pre-auto performs this action before
		downloading new packages."


$lsbdistcodename: Contains the codename ("etch", "lenny", ...) of the client's
	release. While these values come from lsb-release by default, this value
	can be set manually too, e.g. to enable forced upgrades

$custom_sources_list: If non-empty, the contents of this variable are used as
	new sources.list for the node.

Classes
=======

This module contains only the apt class, which sets up all described
functionality.


Resources
=========

File[apt_config]: Use this resource to depend on or add to a completed apt
	configuration

Exec[apt_updated]: After this point, current packages can installed via apt,
	usually used like this:
	Package { require => Exec[apt_updated] }


TODO
====

Enable debian-archive-keyring handling for sarge, lenny and sid.

Enable selection of country-specific mirrors.

Currently this module updates the caches on every run. Running dselect update is
a expensive operation and should be done only on schedule by using apticron.
Sometimes -- especially when initially starting management or deploying new
packages -- a immediate update is really needed to be able to install the right
packages without errors. Thus a method should be devised to be able to specify
with high fidelity when a update should be run and when it is not needed.



[1] Of course, you should check the validity of _this_ key yourself.