Adding a Quota for single Docker containers

[Sengorius]

Goal is to limit the amount of data that is not in the layers of base image, but in the diff of a Docker container.

A goad attempt can be found here: https://stackoverflow.com/questions/29029326/how-to-define-a-disk-quota-for-docker-containers
This one may fit in the DockerExec.

do_enable_quota() {
    local ID=$1
    local QUOTA_MB=$2

    local LOOPBACK=/var/lib/docker/aufs/diff/$ID-loopback
    local LOOPBACK_MOUNT=/var/lib/docker/aufs/diff/$ID-loopback-mount
    local DIFF=/var/lib/docker/aufs/diff/$ID

    docker stop -t=0 $ID
    sudo dd of=$LOOPBACK bs=1M seek=$QUOTA_MB count=0
    sudo mkfs.ext4 -F $LOOPBACK
    sudo mkdir -p $LOOPBACK_MOUNT
    sudo mount -t ext4 -n -o loop,rw $LOOPBACK $LOOPBACK_MOUNT
    sudo rsync -rtv $DIFF/ $LOOPBACK_MOUNT/
    sudo rm -rf $DIFF
    sudo mkdir -p $DIFF
    sudo umount $LOOPBACK_MOUNT
    sudo rm -rf $LOOPBACK_MOUNT
    sudo mount -t ext4 -n -o loop,rw $LOOPBACK $DIFF
    docker start $ID    
}