#!/bin/bash

# Script to be used in the k8s container to unmount filesystems that we don't
# need for calculating free disk space, but that seem to cause problems with
# certain k8s clusters if left mounted.

# Must only use tools that are present in the final k8s image.

# Also the pod must be run with the SYS_ADMIN capability to be able to unmount
# stuff.

set -x

# Ignore errors with unmounting because some paths may not exist
set +e

umount_all_under_dir() {
  for d in $(cat /proc/mounts | grep -Eo "$1[[:alnum:]/~\.-]*"); do
    umount -R $d > /dev/null 2>&1
  done
}

umount_all_under_dir /hostfs/var/lib/docker/aufs/mnt
umount_all_under_dir /hostfs/var/lib/docker/containers
umount_all_under_dir /hostfs/var/lib/kubelet
umount_all_under_dir /hostfs/run/docker/netns
umount_all_under_dir /hostfs/var/lib/rkt

# Take in args for additional paths to unmount
for d in $@; do
  umount_all_under_dir $d
done