title: How do I use variables in a YAML file?
body: <p>I have YAML file which needs to take a variable as an input:</p>
  
  <pre><code>outputters:
      - type        : DateFileOutputter
        name        : logfile
        level       : DEBUG
        date_pattern: '%Y%m%d'
        trunc       : 'false'
        dirname     : "/home/sameera/workspace/project/log"
        filename    : "message.log"
        formatter   :
          date_pattern: '%m/%d/%Y %H:%M:%S'
          pattern     : '%d %l - %m'
          type        : PatternFormatter
  </code></pre>
  
  <p>I want to pass <code>dirname</code> as a parameter, something like:</p>
  
  <pre><code>      dirname     : "&lt;%= LOGFILE_PATH%&gt;"
  </code></pre>
  
  <p>My <code>LOGFILE_PATH</code> is defined in a file called <code>init.rb</code>.</p>