gistfile1.rb

Facter.add('yum_installed_groups') do
        setcode do
                state = -1
                groups = [[], []]
                %x{/usr/bin/yum grouplist -v}.each_line do |line|
                        if line.match('Installed Groups')
                                state = 0
                        elsif line.match('Available Groups')
                                state = 1
                        end
                        if state >= 0
                                q = line.match('\(([^\)]*)\)')
                                if q
                                        groups[state].push(q.captures[0])
                                end
                        end
                end
                # installed groups
                groups[0].join(',')
        end
end