title: Can I specify default values for a config.yml on my java application?
body: <p>I am currently working with my java application with dropwizard.</p>
  
  <p>It works fine and I run it sending a yml file full or parameters.</p>
  
  <p>So, for example, one of them is this one:</p>
  
  <pre><code>reporting:
    enabled: false
  </code></pre>
  
  <p>So, what I want to do is to make this yml file my default and when needed (for future functions) send the value of this <code>var</code></p>
  
  <p>So Id like to do something like this</p>
  
  <pre><code>reporting:
    enabled: ${REPORTING_FLAG:false}
  </code></pre>
  
  <p>Then I can send REPORTING_FLAG as a environment parameter (docker) and should work fine....</p>
  
  <p>The issue is that I see this model is not recognised by my app.</p>
  
  <p>Is there any way I can do it like this? is there an extra configuration to take in consideration? Ive done it before with a spring app but this seems to be different.</p>
  
  <p>Right now I am getting an error that the expected boolean value is not valid (taking the whole line as a string)</p>
  
  <p>Ideas?</p>