title: How to have log4j.properties read env variables
body: <p>This should just be a quick question. I am wondering if this syntax would be correct.</p>
  <p>Inside <code>log4j.properties</code></p>
  <pre><code>log4j.rootLogger=${ROOT_LOGGER:INFO}, console
  </code></pre>
  <p>So what I'm trying to achieve is to have a ROOT_LOGGER env variable and if it's not present, fallback to <code>INFO</code>. I know this works in <code>.yaml</code> files, so just wondering if the same applies here.</p>