--- /dev/null
+Puppet::Parser::Functions::newfunction(
+ :seeded_rand,
+ :arity => 2,
+ :type => :rvalue,
+ :doc => <<-EOS
+Usage: `seeded_rand(MAX, SEED)`. MAX must be a positive integer; SEED is any string.
+
+Generates a random whole number greater than or equal to 0 and less
+than MAX, using the value of SEED for repeatable randomness. If SEED
+starts with "$fqdn:", this is behaves the same as `fqdn_rand`.
+
+EOS
+) do |args|
+ require 'digest/md5'
+
+ raise(ArgumentError, "seeded_rand(): first argument must be a positive integer") unless function_is_integer([args[0]]) and args[0].to_i > 0
+ raise(ArgumentError, "seeded_rand(): second argument must be a string") unless args[1].is_a? String
+
+ max = args[0].to_i
+ seed = Digest::MD5.hexdigest(args[1]).hex
+ Puppet::Util.deterministic_rand(seed,max)
+end