Elastic Beanstalk + EFS where deployment does not delete mount contents

efs.config

packages:
  yum:
    nfs-utils: []

commands:
  0_umount_efs:
    command: sudo umount /efs_mount;
    ignoreErrors: true

files:
  "/opt/elasticbeanstalk/hooks/appdeploy/post/02_enable_efs.sh":
    owner: root
    group: root
    content: |
      #!/usr/bin/env bash
      [ -d /efs_mount ] || sudo mkdir /efs_mount;
      sudo mount -t nfs4 -o nfsvers=4.1 mounttargeturl.efs.us-west-2.amazonaws.com:/ /efs_mount;