title: spring.config.additional-location as environmental variable
body: <p>I have a Docker image for a spring boot 2 app,
  in the image I use spring.config.additional-location to pass a some properties stored in a file on the container itself.</p>
  
  <p>Now I want to use this container in another as a layer in another container or use it in a docker-compose file and I may need to override the spring.config.additional-location.</p>
  
  <p>I tried to override it in an ENV variable:
  <code>SPRING_CONFIG_ADDITIONAL-LOCATION</code> with no success.</p>
  
  <p>What is the proper way to achieve this.</p>