The way to pass variables or parameters to the logback.xml configuration file is to use Java system properties.

Java system properties can be set on the command line as follows: java -DUSER_HOME="/home/sebastien" MyApp2

• USER_HOME is the variable name that you want to pass to the logback.xml configuration file.

Here is how you use it within the logback.xml configuration file:

<configuration>
 
  <appender name="FILE" class="ch.qos.logback.core.FileAppender">
    <file>${USER_HOME}/myApp.log</file> <!-- USER_HOME = /home/sebastien -->
    <encoder>
      <pattern>%msg%n</pattern>
    </encoder>
  </appender>
 
  <root level="debug">
    <appender-ref ref="FILE" />
  </root>
</configuration>

Reference

• http://logback.qos.ch/manual/configuration.html#variableSubstitution2