Testing Puppet Parser Functions

Posted on 08 Sep 2009 in ruby puppet testing

I have been working on some parser functions for Puppet. Specifically I was using the example from the wiki:

require 'ipaddr'
module Puppet::Parser::Functions
	newfunction(:minute_from_address, :type => :rvalue) do |args|
		IPAddr.new(lookupvar('ipaddress')).to_i % 60
	end
end

I wanted to test this function so I started up irb, including the puppet library and my function file…

% irb -r puppet -r time_from_facts.rb
>>

To make sure that the function was loaded I used the ‘function’ call in the Puppet::Parser::Functions.

>> Puppet::Parser::Functions::function(:minute_from_address)
=> "function_minute_from_address"

This shows that the function was loaded. We can then test the function by instanciating a parser scope object:

>> s = Puppet::Parser::Scope.new
=> #<Puppet::Parser::Scope:0x12fb984 @defaults={}, @symtable={}, @namespaces=[""], @tags=[]>

Once the scope is created I can set variables that may be used in the function, specifically ‘ipaddress’ in this example:

>> s.setvar('ipaddress','192.168.205.12')
=> "192.168.205.12"

With the variable set all that is left is to call the function and see what happens:

>> s.function_minute_from_address
=> 52

Hope this helps some of you with testing your Puppet functions.

Tragically L33T