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| author | Kjetil Torgrim Homme <kjetil.homme@redpill-linpro.com> | 2015-12-08 14:59:12 +0100 |
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| committer | Kjetil Torgrim Homme <kjetil.homme@redpill-linpro.com> | 2015-12-08 14:59:12 +0100 |
| commit | 8aecd63378f6dc3aeafe71d91212f613aa0bb829 (patch) | |
| tree | a210a8cf584f4dda07065823db6c9a27b919e939 /lib | |
| parent | 88a9a314c3e9cccbea5add95081655f2c14ec4c1 (diff) | |
| download | puppet-stdlib-8aecd63378f6dc3aeafe71d91212f613aa0bb829.tar.gz puppet-stdlib-8aecd63378f6dc3aeafe71d91212f613aa0bb829.tar.bz2 | |
(#2886) seeded_rand: new function
seeded_rand is needed for repeatable randomness across nodes in a cluster
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/puppet/parser/functions/seeded_rand.rb | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/lib/puppet/parser/functions/seeded_rand.rb b/lib/puppet/parser/functions/seeded_rand.rb new file mode 100644 index 0000000..44e27b8 --- /dev/null +++ b/lib/puppet/parser/functions/seeded_rand.rb @@ -0,0 +1,22 @@ +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 |