puppet host lookup

gistfile1.rb

require 'resolv'

module Puppet::Parser::Functions
  newfunction(:get_ip_addr, :type => :rvalue) do |args|
    # Super sexy regex to match valid IPs
    ip_addr_re = /\b(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\b/
    hostname = args[0].strip
    if hostname =~ ip_addr_re then return hostname end
    begin
      Resolv::DNS.open { |dns| return dns.getaddress hostname }
    rescue Resolv::ResolvError
      return ''
    end
  end
end