Merge pull request #405 from elyscape/feature/fqdn_rand_strings

(MODULES-1715) Add FQDN-based random string generator

1 files changed, 34 insertions, 0 deletions

diff --git a/lib/puppet/parser/functions/fqdn_rand_string.rb b/lib/puppet/parser/functions/fqdn_rand_string.rb
new file mode 100644
index 0000000..785c9fd
--- /dev/null
+++ b/lib/puppet/parser/functions/fqdn_rand_string.rb
@@ -0,0 +1,34 @@
+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.size == 0
+    Puppet::Parser::Functions.function('is_integer')
+    raise(ArgumentError, "fqdn_rand_base64(): first argument must be a positive integer") unless function_is_integer([args[0]]) and args[0].to_i > 0
+    raise(ArgumentError, "fqdn_rand_base64(): second argument must be undef or a string") unless args[1].nil? or 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
+      rand_string << charset[function_fqdn_rand([charset.size, (args + [current.to_s]).join(':')]).to_i]
+    end
+
+    rand_string
+end