[chef] Re: Writing a first library

[Daniel DeLeo < >]

On Monday, May 4, 2015 at 10:49 AM, Andrey Brindeyev wrote:

> Hi, everybody!
> 
> I'm trying to write my first library in Chef 11.18.0 (chef-solo) and using 
> this article as an example:
> https://www.chef.io/blog/2014/03/12/writing-libraries-in-chef-cookbooks/
> 
> However, this piece of code isn't working for me:
> libraries/sensitives_helper.rb:
> require 'chef/mixin/shell_out'
> 
> 
> module SensitivesHelper
> 
> 
> include Chef::Mixin::ShellOut
> 
> 
> def self.retrieve_token(type, version)
> 
> Chef::Log.info "Retrieving sensitive for token #{type}, version #{version}"
> 
> cmd = shell_out!('/usr/local/bin/get-sensitives.sh 
> (http://get-sensitives.sh)', type, version)
> 
> Chef::Log.info "Retrieved sensitive token: #{cmd.stdout}"
> 
> cmd.stdout
> 
> end
> 
> 
> end
> 
> 
> Chef::Recipe.send(:include, SensitivesHelper)
> 
> 
> 
> 
> When I try to use it in recipe, it's causing NoMethodError: undefined 
> method `shell_out!' for SensitivesHelper:Module
> 
> Usage example:
> 
> user = ''
> ruby_block "get sensitives" do
> block do
> user = SensitivesHelper.retrieve_token('a', 'b')
> end
> end
> 
> Any help is appreciated.
> 
> -- 
> Andrey. 

The issue is class vs. instance methods. This blog post describes the 
difference: 
http://www.railstips.org/blog/archives/2009/05/11/class-and-instance-methods-in-ruby/

When mixing in methods for use as class methods, you need to use extend 
instead of include: This post describes the difference between those two: 
http://www.railstips.org/blog/archives/2009/05/15/include-vs-extend-in-ruby/

HTH,

-- 
Daniel DeLeo