#!/bin/sh

# Copyright 2017 The Kubernetes Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# This driver implements a tmpfs with a pre-populated file index.html.
# Attach is required, but it is a no-op that always returns success.

FLEX_DUMMY_LOG=${FLEX_DUMMY_LOG:-"/tmp/flex-dummy.log"}

VALID_MNTDEVICE=foo

# attach always returns one valid mount device so a different device
# showing up in a subsequent driver call implies a bug
validateMountDeviceOrDie() {
	MNTDEVICE=$1
	CALL=$2
	if [ "$MNTDEVICE" != "$VALID_MNTDEVICE" ]; then
		log "{\"status\":\"Failure\",\"message\":\"call "${CALL}" expected device "${VALID_MNTDEVICE}", got device "${MNTDEVICE}"\"}"
		exit 0
	fi
}

log() {
	printf "$*" >&1
}

debug() {
	echo "$(date) $*" >> "${FLEX_DUMMY_LOG}"
}

attach() {
	debug "attach $@"
	log "{\"status\":\"Success\",\"device\":\""${VALID_MNTDEVICE}"\"}"
	exit 0
}

detach() {
	debug "detach $@"
	log "{\"status\":\"Success\"}"
	exit 0
}

waitforattach() {
	debug "waitforattach $@"
	MNTDEVICE=$1
	validateMountDeviceOrDie "$MNTDEVICE" "waitforattach"
	log "{\"status\":\"Success\",\"device\":\""${MNTDEVICE}"\"}"
	exit 0
}

isattached() {
	debug "isattached $@"
	log "{\"status\":\"Success\",\"attached\":true}"
	exit 0
}

domountdevice() {
	debug "domountdevice $@"
	MNTDEVICE=$2
	validateMountDeviceOrDie "$MNTDEVICE" "domountdevice"
	MNTPATH=$1
	mkdir -p ${MNTPATH} >/dev/null 2>&1
	mount -t tmpfs none ${MNTPATH} >/dev/null 2>&1
	echo "Hello from flexvolume!" >> "${MNTPATH}/index.html"
	log "{\"status\":\"Success\"}"
	exit 0
}

unmountdevice() {
	debug "unmountdevice $@"
	MNTDEVICE=$2
	validateMountDeviceOrDie "$MNTDEVICE" "unmountdevice"
	MNTPATH=$1
	rm "${MNTPATH}/index.html" >/dev/null 2>&1
	umount ${MNTPATH} >/dev/null 2>&1
	log "{\"status\":\"Success\"}"
	exit 0
}

op=$1

if [ "$op" = "init" ]; then
	debug "init $@"
	log "{\"status\":\"Success\",\"capabilities\":{\"attach\":true}}"
	exit 0
fi

shift

case "$op" in
	attach)
		attach $*
		;;
	detach)
		detach $*
		;;
	waitforattach)
		waitforattach $*
		;;
	isattached)
		isattached $*
		;;
	mountdevice)
		domountdevice $*
		;;
	unmountdevice)
		unmountdevice $*
		;;
	*)
		log "{\"status\":\"Not supported\"}"
		exit 0
esac

exit 1