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-rw-r--r--README.markdown15
-rw-r--r--lib/puppet/parser/functions/fqdn_rotate.rb24
2 files changed, 29 insertions, 10 deletions
diff --git a/README.markdown b/README.markdown
index c140af4..8ed3d9b 100644
--- a/README.markdown
+++ b/README.markdown
@@ -259,7 +259,20 @@ fqdn_rand_string(10, '', 'custom seed')
#### `fqdn_rotate`
-Rotates an array a random number of times, based on a node's fqdn. *Type*: rvalue.
+Rotates an array or string a random number of times, combining the `$fqdn` fact and an optional seed for repeatable randomness.
+
+*Usage:*
+~~~
+fqdn_rotate(VALUE, [SEED])
+~~~
+*Examples:*
+~~~
+fqdn_rotate(['a', 'b', 'c', 'd'])
+fqdn_rotate('abcd')
+fqdn_rotate([1, 2, 3], 'custom seed')
+~~~
+
+*Type*: rvalue.
#### `get_module_path`
diff --git a/lib/puppet/parser/functions/fqdn_rotate.rb b/lib/puppet/parser/functions/fqdn_rotate.rb
index e1a50e6..b66431d 100644
--- a/lib/puppet/parser/functions/fqdn_rotate.rb
+++ b/lib/puppet/parser/functions/fqdn_rotate.rb
@@ -2,16 +2,23 @@
# fqdn_rotate.rb
#
-module Puppet::Parser::Functions
- newfunction(:fqdn_rotate, :type => :rvalue, :doc => <<-EOS
-Rotates an array a random number of times based on a nodes fqdn.
- EOS
- ) do |arguments|
+Puppet::Parser::Functions.newfunction(
+ :fqdn_rotate,
+ :type => :rvalue,
+ :doc => "Usage: `fqdn_rotate(VALUE, [SEED])`. VALUE is required and
+ must be an array or a string. SEED is optional and may be any number
+ or string.
+
+ Rotates VALUE a random number of times, combining the `$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.shift
+ 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 :