Accessing Chef node attributes

Using a helper method is part of good Clean Chef code.

It shortens evaluation from node["my_namespace"]["my_attribute"] to cb_attr("my_attribute").

module MyCookbook
  module Helpers
    def cb_attr(name)
      attribute_namespace = node["my_cookbook"]
      if attribute_namespace.key?(name)
        attribute_namespace[name]
      else
        raise "Undefined node attribute `#{name}`"
      end
    end
  end
end