--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/modules/stdlib/lib/puppet/parser/functions/fqdn_rand_string.rb	Fri Jan 03 19:56:04 2020 +0000
@@ -0,0 +1,35 @@
+Puppet::Parser::Functions.newfunction(
+  :fqdn_rand_string,
+  :arity => -2,
+  :type => :rvalue,
+  :doc => "Usage: `fqdn_rand_string(LENGTH, [CHARSET], [SEED])`. LENGTH is
+  required and must be a positive integer. CHARSET is optional and may be
+  `undef` or a string. SEED is optional and may be any number or string.
+
+  Generates a random string LENGTH characters long using the character set
+  provided by CHARSET, combining the `$fqdn` fact and the value of SEED for
+  repeatable randomness. (That is, each node will get a different random
+  string from this function, but a given node's result will be the same every
+  time unless its hostname changes.) Adding a SEED can be useful if you need
+  more than one unrelated string. CHARSET will default to alphanumeric if
+  `undef` or an empty string.",
+) do |args|
+  raise(ArgumentError, 'fqdn_rand_string(): wrong number of arguments (0 for 1)') if args.empty?
+  Puppet::Parser::Functions.function('is_integer')
+  raise(ArgumentError, 'fqdn_rand_string(): first argument must be a positive integer') unless function_is_integer([args[0]]) && args[0].to_i > 0
+  raise(ArgumentError, 'fqdn_rand_string(): second argument must be undef or a string') unless args[1].nil? || args[1].is_a?(String)
+
+  Puppet::Parser::Functions.function('fqdn_rand')
+
+  length = args.shift.to_i
+  charset = args.shift.to_s.chars.to_a
+
+  charset = (0..9).map { |i| i.to_s } + ('A'..'Z').to_a + ('a'..'z').to_a if charset.empty?
+
+  rand_string = ''
+  for current in 1..length # rubocop:disable Style/For : An each loop would not work correctly in this circumstance
+    rand_string << charset[function_fqdn_rand([charset.size, (args + [current.to_s]).join(':')]).to_i]
+  end
+
+  rand_string
+end