pkginventory.rb

# Generates facts of the version pkg_foo => 'version'

begin
  require 'puppet'
  pkgs = Puppet::Type.type(:package).instances

  pkgs.each do |pkg|
    Facter.add("pkg_#{pkg[:name]}") do
      value = pkg.provider.properties[:ensure]
      if value != :absent
        setcode { value }
      end
    end
  end
rescue => LoadError
  Facter.warn 'Unable to load puppet; cannot generate pkg facts.'
end