= Facter Tweaks =

== New facts testing ==
While you are writing new facts please refer to [http://docs.puppetlabs.com/guides/custom_facts.html puppetlabs documentation].  In short do something like:
{{{
$ mkdir -p ~/lib/ruby/facter ; export RUBYLIB=~/lib/ruby
$ cp /path/to/hardware_platform.rb $RUBYLIB/facter
$ facter hardware_platform
SUNW,Sun-Blade-1500
}}}

== New facts distributing == 
To distribute your new facts to puppet clients make a module (preferably the one where you are using this fact), e.g.
{{{
$ mkdir -p /etc/puppet/modules/myfirst_module/lib/facter
cp myfirstfact.rb /etc/puppet/modules/myfirst_module/lib/facter
}}}

If you are distributing facts this way you can test them on the client by setting FACTERLIB environment variable:
{{{
export FACTERLIB=/var/lib/puppet/lib/facter
facter
}}}
== videocard fact ==

This ruby snippet adds a videocard fact to facter.  You can use this fact to decide if you need to install any proprietary video card drivers.  Place in /usr/lib/ruby/site_ruby/1.8/facter/videocard.rb
{{{
#!ruby
# Josko Plazonic - lifted from Josko March 14, 2011 by Thomas Uphill
require 'facter'

Facter.add("videocard") do
	confine :kernel => :linux
	ENV["PATH"]="/bin:/sbin:/usr/bin:/usr/sbin"
	setcode do
		controllers = []
		lspciexists = system "/bin/bash -c 'which lspci >&/dev//null'"
		if $?.exitstatus == 0
			output = %x{lspci}
			output.each {|s|
				controllers.push($1) if s =~ /VGA compatible controller: (.*)/
			}
		end
		controllers
	end
end
}}}

After installing you should be able to see the fact like so:
{{{
[root@host ~]# facter |grep video
videocard => Intel Corporation 82945G/GZ Integrated Graphics Controller (rev 02)
[root@host ~]# 
}}}
== Kernel versions fact ==
This fact requires [http://rubyforge.org/projects/ruby-rpm/ rubygem ruby-rpm].  Either install it from source or if you are using a RHEL 6 based distro (like PUIAS 6 or any other clone) please feel free to use the relevant rpm from our unsupported repo (rubygem-ruby-rpm-1.3.0-* from [http://puias.princeton.edu/data/puias/unsupported/6/ repository]):
{{{
# Josko Plazonic 20110314
require 'rubygems'
require 'rpm'

begin
	Facter.architecture
rescue
	Facter.loadfacts()
end
db = RPMdb.open()
allkernels=db.package("kernel").collect { |x| RPM::Version.new(x[1]+"-"+x[2]) }.sort
db.close()

Facter.add("kernelnewest") do
	confine :kernel => :linux
	setcode do
		allkernels[-1].v+"-"+allkernels[-1].r+"."+Facter.architecture
	end
end

Facter.add("kerneloldest") do
	confine :kernel => :linux
	setcode do
		allkernels[0].v+"-"+allkernels[0].r+"."+Facter.architecture
	end
end
}}}
This fact provides kernelnewest and kerneloldest facts.  They can be used, together with kernelrelease fact, in puppet recipes to figure out whether the puppet client is currently running the latest kernel version as well as whether there are alternate versions of the kernel installed.  Example recipes that use this module will be posted on the [wiki:PuppetTweaks puppet recipes page].