title: reflection of erb variables
body: <p>I'm using a puppet template, which does an erb interpretation of the template file.  I'd like to know all the variables available to me, however, there are variables available (e.g., fqdn) that are not listed by any of the reflection methods I'm aware of, specifically, none of these:</p>
  
  <pre><code>&lt;% Module.constants.each do |v| %&gt;# module constant: &lt;%= v %&gt;
  &lt;% end %&gt;
  &lt;% Kernel.local_variables.each do |v| %&gt;# local variable: &lt;%= v %&gt;
  &lt;% end %&gt;
  &lt;% Kernel.instance_variables.each do |v| %&gt;# instance variable: &lt;%= v %&gt;
  &lt;% end %&gt;
  &lt;% Module.class_variables.each do |v| %&gt;# class variable: &lt;%= v %&gt;
  &lt;% end %&gt;
  &lt;% Kernel.global_variables.each do |v| %&gt;# global variable: &lt;%= v %&gt;
  &lt;% end %&gt;
  </code></pre>
  
  <p>Is there an extra reflection method for erb that will reveal these to me?</p>