Puppet Function: seeded_rand

Defined in:
puppet/modules/stdlib/lib/puppet/parser/functions/seeded_rand.rb
Function type:
Ruby 3.x API

Overview

seeded_rand() ⇒ Any

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`.

Returns:

  • (Any) 


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# File 'puppet/modules/stdlib/lib/puppet/parser/functions/seeded_rand.rb', line 1

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