AutoLoader

autoload_helpers.pp

# autoloader.pp
class nagios::autoload_helpers {
  $helpers = get_nagios_helpers()

  case $::puppetversion {
    /^3/: { include $helpers }
    default: {
      nagios::autoload_helpers::import_shim { $helpers: }
    }
  }
}

get_nagios_helpers.rb

module Puppet::Parser::Functions
  newfunction(:get_nagios_helpers, 
              :type => :rvalue,
              :doc => "Grab all modules that have nagios helpers for import") do

  module_path = File.expand_path('..',
        Puppet::Module.find('nagios',compiler.environment.to_s).path)

  helpers = Dir["#{module_path}/**/nagios/helpers.pp"].map do |d| 
    "#{d.split('/')[-4]}::nagios::helpers" 
  done

  helpers
  end
end

init.pp

  include nagios::autoload_helpers