lizardfs

#!/bin/bash
##################################
# Credits to the original authors:
# https://github.com/lowet84  (original author)
# https://github.com/M0nsieurChat (updates for Kubernetes >=1.6.3 compatibility)
##################################
#########
# Derived from M0nsieurChat's version and overhauled for Kubernetes >= 1.7.x compatiblity
#########

VERSION='v1.8.0'

DEBUG=${MFSDEBUG:-0}
[[ -f /.mfsdebug ]] && DEBUG=1

date=$(date '+%Y%m%d/%H:%M:%S')
d_log='/var/log/flex-volume/lizardfs'
op="$1"

if [[ ! -d "${d_log}" ]]; then
	mkdir -p "${d_log}"
	chmod o= "${d_log}"
fi

usage() {
	exec 1>&2
	printf "usage: %s {init|mount|unmount} ...\n" "$(basename $0)"
	echo   "          init"
	echo   "          mount <mount dir> <json params>"
	echo   "          unmount <mount dir>"
	echo   "version: ${VERSION}"
	exit 1
}

err() {
	(( DEBUG )) && echo "${date}:ERROR: $*" >> "${d_log}/debug.log"
	echo -ne $* 1>&2 '\n'
}

log() {
	(( DEBUG )) && echo "${date}:OUTPUT: $*" >> "${d_log}/debug.log"
	echo -ne $* >&1
}

logNotSupported() {
	log '{"status": "Not supported"}'
        exit 0
}

logSuccess() {
	log '{"status": "Success"}'
	exit 0
}

ismounted() {
	local MNTPATH="$1"

	if [[ ! -d "${MNTPATH}" ]]; then
		return 1
	fi

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

	return 1
}

unmount() {
	(( DEBUG )) && echo "${date}:DOUNMOUNT: $@" >> "${d_log}/debug.log"

	local MNTPATH="$1"

	if ! ismounted "${MNTPATH}"; then
		logSuccess
	fi

	if ! umount "${MNTPATH}" &> /dev/null; then
		err '{"status": "Failed", "message": "Failed to unmount volume at: '"${MNTPATH}"'}'
		exit 1
	fi

	if ! rmdir "${MNTPATH}" &> /dev/null; then
		# Only emit an error message, but allow as success since it was unmounted correctly above
		err '{"status": "Failed", "message": "Failed to unmount volume at: '"${MNTPATH}"'}'
	fi

	logSuccess
}

domount() {
	(( DEBUG )) && echo "${date}:DOMOUNT: $@" >> "${d_log}/debug.log"

	local MNTPATH="$1"
	local LFSFOLDER="${MNTPATH##*/}"

	local f_config=
	local from_secret=0
	local msgPassword=
	local HOST=
	local PASSWORD=

	# Okay, I want to provision the folder in the root of my LizardFS : each pod bound to a PVC bound to a PV has a folder created (folder name is the PV name bound to the PVC)

	# It appears the controllers do a first request on mount with the following arguments :
	# /var/lib/kubelet/plugins/kubernetes.io/flexvolume/lowet84/lizardfs/mounts/mfs-volume /dev/bounded-local {"host":"mfsmaster","kubernetes.io/fsType":"","kubernetes.io/readwrite":"rw","port":"9421"}
	#   $PATH (we don't want to mount that obvisouly) 			$DEV 	$JSON_OPTS
	# I don't know the usefulness of this, thus, we return success for the subsequent query with the correct parameters

	#TT:FIXME???: I'm not sure if this is still the case for 1.7.x with init() emitting "capabilities": {"attach": false}
	if (( $# == 3 )); then
		logSuccess
	elif ismounted "${MNTPATH}"; then
		exit 0
	fi

	# /var/lib/kubelet/pods/c6f7f490-6009-11e7-83d0-005056af1192/volumes/lowet84~lizardfs/mfs-volume {"host":"mfsmaster","kubernetes.io/fsType":"","kubernetes.io/readwrite":"rw","port":"9421"}
	#  $PATH		$JSON_OPTS

	HOST=$(jq -r '.host // empty' <<<"$2")
	if [[ -z "${HOST}" ]]; then
		# Error out if 'host' isn't provided
		err '{"status": "Failure", "message": "Cannot mount lizardfs volume without a specified host"}'
		exit 1
	fi

	# Defaults to port 9421
	PORT=$(jq -r '.port // "9421"' <<<"$2")

	# Special handling is needed if mfsfolder is in play
	MFSSUBFOLDER=$(jq -r '.mfssubfolder // empty' <<<"$2")

	# Override derived LFSFOLDER with given MFSSUBFOLDER
	if [[ -n "${MFSSUBFOLDER}" ]]; then
		LFSFOLDER="${MFSSUBFOLDER}"
	fi

	#Password precedence:
	# 1) mfspasswd option
	# 2) kubernetes secret
	PASSWORD=$(jq -r '.mfspassword // empty' <<<"$2")
	if [[ -z "${PASSWORD}" ]]; then
		#pull from secret
		#NOTES
		# 1) @base64d requires: jq > v1.5
		# 2) Secret object must have spec type: fq/lizardfs
		#PASSWORD=$(jq -r '.["kubernetes.io/secret/mfspassword"] | @base64d // empty' <<<"$2")
		PASSWORD=$(jq -r '.["kubernetes.io/secret/mfspassword"] // empty' <<<"$2" | base64 -d)
		[[ -z "${PASSWD}" ]] && from_secret=1
	fi

	if ! mkdir -p "${MNTPATH}" &> /dev/null; then
		err '{"status": "Failure", "message": "Failed to create MNTPATH directory: '"${MNTPATH}"'}'
		exit 1
	fi

	# Past the point of no return, safe to setup mfsconfig
	if f_config=$(mktemp --tmpdir=/tmp mfsmount-XXXXXXXX.conf); then
		chmod 600 "${f_config}"
		# Make sure any sensitive info is erased
		(( ! DEBUG )) && trap "/bin/rm -f ${f_config} &> /dev/null" EXIT
	else
		err '{"status": "Failure", "message": "Failed to setup mfsmount config file"}'
		exit 1
	fi

	# Push out mfs* option to the config file converting JSON object to 'key=value' store
	#NOTE: if there is a more idiomatic jq way to accomplish this, please let me know
	{
		jq -r 'to_entries[] | if .key|startswith("mfs") then .key+"="+.value else empty end' <<<"$2"
		(( from_secret )) && echo "mfspassword=${PASSWORD}"
	} > "${f_config}"

	(( DEBUG )) && echo "${date}:CALL: mfsmount -H ${HOST} -P ${PORT} -c ${f_config} -o big_writes,nosuid,nodev,noatime -S ${LFSFOLDER} ${MNTPATH} // JSON: $2" | scrub_password >> "${d_log}/debug.log"
	MFSMOUNT_OUTPUT=$(mfsmount -H "${HOST}" -P "${PORT}" -c ${f_config} -o big_writes,nosuid,nodev,noatime -S "${LFSFOLDER}" "${MNTPATH}" 2>&1)
	if [ "$?" -ne 0 ]; then
		err '{"status": "Failure", "message": "Failed to mount lizardfs at: '"${MNTPATH}"' :: ['"${MFSMOUNT_OUTPUT}"']"}'
		exit 1
	fi

	logSuccess
}

scrub_password() {
	if (( DEBUG )); then
		cat
	else
		sed -e 's/\(mfspassword"\):"[^"]\+"/\1:"<redacted>"/g'
	fi
}

if [[ "$op" = "init" ]]; then
	(( DEBUG )) && echo "${date}:INIT: $@" >> "${d_log}/debug.log"

	log '{"status": "Success", "capabilities": {"attach": false, "selinuxRelabel": false}}'
	exit 0
fi

if (( $# < 2 )); then
	usage
fi

shift

case "$op" in
	mount)   domount $*;;
	unmount) unmount $*;;
	*)       logNotSupported;;
esac