Merge pull request #462 from elyscape/fix/fqdn_rotate_seeds_with_argument

fqdn_rotate: Don't use the value itself as part of the random seed

1 files changed, 15 insertions, 9 deletions

diff --git a/lib/puppet/parser/functions/fqdn_rotate.rb b/lib/puppet/parser/functions/fqdn_rotate.rb
index d9741a0..b66431d 100644
--- a/lib/puppet/parser/functions/fqdn_rotate.rb
+++ b/lib/puppet/parser/functions/fqdn_rotate.rb
@@ -2,16 +2,23 @@
 # fqdn_rotate.rb
 #
 
-module Puppet::Parser::Functions
-  newfunction(:fqdn_rotate, :type => :rvalue, :doc => <<-EOS
-Rotates an array a random number of times based on a nodes fqdn.
-    EOS
-  ) do |arguments|
+Puppet::Parser::Functions.newfunction(
+  :fqdn_rotate,
+  :type => :rvalue,
+  :doc => "Usage: `fqdn_rotate(VALUE, [SEED])`. VALUE is required and
+  must be an array or a string. SEED is optional and may be any number
+  or string.
+
+  Rotates VALUE a random number of times, combining the `$fqdn` fact and
+  the value of SEED for repeatable randomness. (That is, each node will
+  get a different random rotation 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 rotation.") do |args|
 
     raise(Puppet::ParseError, "fqdn_rotate(): Wrong number of arguments " +
-      "given (#{arguments.size} for 1)") if arguments.size < 1
+      "given (#{args.size} for 1)") if args.size < 1
 
-    value = arguments[0]
+    value = args.shift
     require 'digest/md5'
 
     unless value.is_a?(Array) || value.is_a?(String)
@@ -31,7 +38,7 @@ Rotates an array a random number of times based on a nodes fqdn.
 
     elements = result.size
 
-    seed = Digest::MD5.hexdigest([lookupvar('::fqdn'),arguments].join(':')).hex
+    seed = Digest::MD5.hexdigest([lookupvar('::fqdn'),args].join(':')).hex
     # deterministic_rand() was added in Puppet 3.2.0; reimplement if necessary
     if Puppet::Util.respond_to?(:deterministic_rand)
       offset = Puppet::Util.deterministic_rand(seed, elements).to_i
@@ -51,7 +58,6 @@ Rotates an array a random number of times based on a nodes fqdn.
     result = string ? result.join : result
 
     return result
-  end
 end
 
 # vim: set ts=2 sw=2 et :