Puppet module for outputting json in a sorted consistent way

sorted_json.rb

#
# sorted_json.rb
# Puppet module for outputting json in a sorted consistent way. I use it for creating config files with puppet

require 'json'

def sorted_json(json)
    if (json.kind_of? String)
      return json.to_json
    elsif (json.kind_of? Array)
      arrayRet = []
      json.each do |a|
        arrayRet.push(sorted_json(a))
      end
      return "[" << arrayRet.join(',') << "]";
    elsif (json.kind_of? Hash)
      ret = []
      json.keys.sort.each do |k|
        ret.push(k.to_json << ":" << sorted_json(json[k]))
      end
      return "{" << ret.join(",") << "}";
    end
    raise Exception("Unable to handle object of type " + json.class)
end

module Puppet::Parser::Functions
  newfunction(:sorted_json, :type => :rvalue, :doc => <<-EOS
This function takes data, outputs making sure the hash keys are sorted

*Examples:*

    sorted_json({'key'=>'value'})

Would return: {'key':'value'}
    EOS
  ) do |arguments|

    raise(Puppet::ParseError, "sorted_json(): Wrong number of arguments " +
      "given (#{arguments.size} for 1)") if arguments.size != 1

    json = arguments[0]
    return sorted_json(json)

  end
end

# vim: set ts=2 sw=2 et :

+2 on stdlib

edit: and this is 4 years old, it'd be about time

Simple puppet 4 edition

#
# LICENSE: https://gist.github.com/aj-jester/e0078c38db9eb7c1ef45
#
require 'json'

Puppet::Functions.create_function(:sorted_json) do
  dispatch :sorted_json do
    param 'Hash', :arg
  end

  def sorted_generate(obj)
    case obj
      when Fixnum, Float, TrueClass, FalseClass, NilClass
        return obj.to_json
      when String
        # Convert quoted integers (string) to int
        return (obj.match(/\A[-]?[0-9]+\z/) ? obj.to_i : obj).to_json
      when Array
        arrayRet = []
        obj.each do |a|
          arrayRet.push(sorted_generate(a))
        end
        return "[" << arrayRet.join(',') << "]";
      when Hash
        ret = []
        obj.keys.sort.each do |k|
          ret.push(k.to_json << ":" << sorted_generate(obj[k]))
        end
        return "{" << ret.join(",") << "}";
      else
        raise Exception("Unable to handle object of type <%s>" % obj.class.to_s)
    end
  end # end def

  def sorted_json(h)
    sorted_generate(h)
  end
end

https://forge.puppet.com/puppetlabs/stdlib#to_json
https://forge.puppet.com/puppetlabs/stdlib#to_json_pretty