title: How ${application.home} resolved in conf/logback.xml in play framework?
body: <p>I am using Play Framework 2.4. This is a part of the default conf/logback.xml file Play 2.4</p>
  
  <pre><code>&lt;!--
    ~ Copyright (C) 2009-2016 Lightbend Inc. &lt;https://www.lightbend.com&gt;
    --&gt;
  &lt;!-- The default logback configuration that Play uses if no other configuration is provided --&gt;
  &lt;configuration&gt;
  
    &lt;conversionRule conversionWord="coloredLevel" converterClass="play.api.libs.logback.ColoredLevel" /&gt;
  
    &lt;appender name="FILE" class="ch.qos.logback.core.FileAppender"&gt;
       &lt;file&gt;${application.home}/logs/application.log&lt;/file&gt;
       &lt;encoder&gt;
         &lt;pattern&gt;%date [%level] from %logger in %thread - %message%n%xException&lt;/pattern&gt;
       &lt;/encoder&gt;
    &lt;/appender&gt;
  &lt;/configuration&gt;
  </code></pre>
  
  <p>You can see full version from <a href="https://www.playframework.com/documentation/2.5.x/SettingsLogger" rel="nofollow noreferrer">here</a>. My question is how exactly that ${application.home} can be resolved? I read <a href="https://stackoverflow.com/a/35321593/5715934">this</a> answer, but didn't work.</p>
  
  <p>The exact situation is when I removed <code>${application.home}</code> from <code>&lt;file&gt;&lt;/file&gt;</code> tag, the <code>logs</code> folder will be created outside (in Parallel with) the dist(play-restful-docker-1.0-SNAPSHOT) folder. (in production)</p>
  
  <p>I can add the dist-name (play-restful-docker-1.0-SNAPSHOT) replacing ${application.home} and it creates <code>logs</code> folder inside the dist and works perfect. But it is not a good practice since it will have to be changed per every new version.</p>