flex volume make-shared

shared-mount.sh

#!/bin/bash
# Notes:
#  - Please install "jq" package before using this driver.
usage() {
	err "Invalid usage. Usage: "
	err "\t$0 init"
	err "\t$0 attach <json params>"
	err "\t$0 detach <mount device>"
	err "\t$0 mount <mount dir> <mount device> <json params>"
	err "\t$0 unmount <mount dir>"
	exit 1
}

err() {
	echo -ne $* 1>&2
}

log() {
	echo -ne $* >&1
}

ismounted() {
	MOUNT=`findmnt -n ${MNTPATH} 2>/dev/null | cut -d' ' -f1`
	if [ "${MOUNT}" == "${MNTPATH}" ]; then
		echo "1"
	else
		echo "0"
	fi
}

attach() {
	MNTPATH=$(echo $1 | jq -r '.fromPath')
    if [ ! -d "${MNTPATH}" ]; then
        mkdir -p ${MNTPATH} &> /dev/null
		if [ $? -ne 0 ]; then
			err "{ \"status\": \"Failure\", \"message\": \"Failed to create source directory ${MNTPATH}\"}"
			exit 1
		fi
    fi

	if [ $(ismounted) -eq 0 ] ; then
	    mount --rbind ${MNTPATH} ${MNTPATH} &> /dev/null
	    if [ $? -ne 0 ]; then
		    err "{ \"status\": \"Failure\", \"message\": \"Failed to bind mount ${MNTPATH}\"}"
		    exit 1
	    fi
	fi

    mount --make-rshared $MNTPATH &> /dev/null
	if [ $? -ne 0 ]; then
        umount ${MNTPATH} &> /dev/null
		err "{ \"status\": \"Failure\", \"message\": \"Failed to mark mount directory for ${MNTPATH} as shared\"}"
		exit 1
	fi

	log "{\"status\": \"Success\", \"device\":\"${MNTPATH}\"}"
	exit 0
}

detach() {
    unmount $1
}

domount() {
	MNTPATH=$1
	FROM_PATH=$2

	mkdir -p ${MNTPATH} &> /dev/null

	mount --rbind ${FROM_PATH} ${MNTPATH} &> /dev/null
	if [ $? -ne 0 ]; then
		err "{ \"status\": \"Failure\", \"message\": \"Failed to mount ${FROM_PATH} at ${MNTPATH}\"}"
		exit 1
	fi

    mount --make-rshared $MNTPATH &> /dev/null
	if [ $? -ne 0 ]; then
        umount ${MNTPATH} &> /dev/null
		err "{ \"status\": \"Failure\", \"message\": \"Failed to mark mount directory for ${MNTPATH} as shared\"}"
		exit 1
	fi

	log "{\"status\": \"Success\"}"
	exit 0
}

unmount() {
	MNTPATH=$1
	if [ $(ismounted) -eq 0 ] ; then
		log "{\"status\": \"Success\"}"
		exit 0
	fi

	umount ${MNTPATH} &> /dev/null
	if [ $? -ne 0 ]; then
		err "{ \"status\": \"Failed\", \"message\": \"Failed to unmount volume at ${MNTPATH}\"}"
		exit 1
	fi
	rmdir ${MNTPATH} &> /dev/null

	log "{\"status\": \"Success\"}"
	exit 0
}

op=$1

if [ "$op" = "init" ]; then
	log "{\"status\": \"Success\"}"
	exit 0
fi

if [ $# -lt 2 ]; then
	usage
fi

shift

case "$op" in
	attach)
		attach $*
		;;
	detach)
		detach $*
		;;
	mount)
		domount $*
		;;
	unmount)
		unmount $*
		;;
	*)
		usage
esac

exit 1