title: unable to mount volume to spark.kubernetes.executor
body: <p>I am trying to read a file from server in spark cluster mode using kubernetes, so i put my file on all workers and i mount driver volume using<br>
  val conf = new SparkConf().setAppName("sparksetuptest")
  .set("spark.kubernetes.driver.volumes.hostPath.host.mount.path", "/file-directory")</p>
  
  <p>Everything works fine here but when i execute it shows that file not found at specific location.
  So i mount directory to executor with .set("spark.kubernetes.executor.volumes.hostPath.host.mount.path", "/file-directory")
  But now i am not able to execute program it stuck in a never ending process while fetching data.</p>
  
  <p>Please suggest something, so that i can mount my directory with executor and read that file.</p>