File_exists() not working

  • OS Version/build
  • App version

I am trying to integrate an image library into my docker based project. In one of the supplied source files I see file exists() is failing. I have a directory on the host that I am using to debug the code (see path below). I am starting to think that my php code can’t see my directory on the host.
The code uses file_exists() to see if a certain module is at /opt/docker-substantiator/app/application/views/list.php. it is a pretty straightforward function call and I think this must be a Docker induced failure. I called getcwd and it is /app. Any idea why I can’t see if this file exist?. Remember, my php is running in a container.