#!/bin/bash

# License: BeeGFS EULA

# constant definitions
# (for configurables see below)

DEFAULT_CFG_PATH="/etc/beegfs/beegfs-meta.conf"
STORAGE_PATH_CFG_KEY="storeMetaDirectory"
MGMTD_CFG_KEY="sysMgmtdHost"
ALLOW_INIT_CFG_KEY="storeAllowFirstRunInit"
FS_UUID_CFG_KEY="storeFsUUID"
SERVER_NUMID_FILE="nodeNumID"
FORMAT_FILENAME="format.conf"
FORMAT_FILE_VERSION="4"
XATTR_CFG_KEY="storeUseExtendedAttribs"

print_usage()
{
	echo
	echo "DESCRIPTION: Initialize metadata storage directory for beegfs-meta server daemon"
	echo "and update the beegfs-meta config file."
	echo
	echo "USAGE: `basename $0` -p <metadata_path> [options]"
	echo
	echo " Mandatory Options:"
	echo 
	echo "   -p <path> - Path to metadata storage directory that is to be initialized."
	echo "               (Path will also be added to config file.)"
	echo
	echo " Recommended Options:"
	echo
	echo "   -s <num>  - Assign the given numeric ID to the server of this storage"
	echo "               directory (range 1..65535). (Default: Randomly select a free ID.)"
	echo
	echo "   -m <host> - Hostname (or IP address) of management server."
	echo "               (Will be stored in server config file.)"
	echo
	echo " Other Options:"
	echo
	echo "   -C        - Do not update server config file."
	echo
	echo "   -c <path> - Path to server config file."
	echo "               (Default: ${DEFAULT_CFG_PATH})"
	echo
	echo "   -f        - Force actions, ignore warnings."
	echo
	echo "   -h        - Print this help."
	echo
	echo "   -u        - Do not disable usage of uninitialized storage directory in config"
	echo "               file and do not store the UUID of the underlying fs."
	echo
	echo "   -x        - Do not store metadata as extended attributes."
	echo
	echo "NOTES:"
	echo " * All given IDs must be unique in their service class for the whole file system"
	echo "   instance, i.e. there can only be one beegfs-meta service with ID 2, but there"
	echo "   can also be a beegfs-storage service with ID 2 in the file system."
	echo
	echo " * BeeGFS servers can also run without pre-initializing storage directories, if"
	echo "   storeAllowFirstRunInit=true is set in the server config files (which is"
	echo "   usually not recommended)."
	echo
	echo "EXAMPLES:"
	echo " * Numeric IDs can generally be chosen arbitrarily. However, it is usually a"
	echo "   good idea to pick a numeric ID that matches the hostname, e.g. if the"
	echo "   hostname is \"meta02\", you would use \"2\" as numeric ID for the beegfs-meta"
	echo "   service on this server."
	echo
	echo " * Example 1) Initialize metadata storage directory of first metadata server and"
	echo "   set \"storage01\" as management daemon host in config file:"
	echo "   $ `basename $0` -p /mnt/myraid1/beegfs-meta -s 1 -m storage01"
	echo
}

# initialize storage directory (if enabled)
init_storage_dir()
{
	# check if storage path is defined

	if [ -z "${STORAGE_PATH}" ]; then
		return 0
	fi

	# create storage path

	echo "Preparing storage directory: ${STORAGE_PATH}"
	mkdir -p "${STORAGE_PATH}"

	# make sure storage dir is empty

	if [ -z "${FORCE_ACTIONS}" ] && [ "$(ls -AI lost+found ${STORAGE_PATH} )" ]; then
		echo " * ERROR: Storage directory is not empty. Initialization of non-empty" \
			"directories can lead to data loss or orphaned data. ('-f' disables this check.)"
		exit 1
	fi

	# create format file

	echo " * Creating ${FORMAT_FILENAME} file..."

	FORMAT_FILE_PATH="${STORAGE_PATH}/${FORMAT_FILENAME}"
	echo "# This file was auto-generated. Do not modify it!" >> ${FORMAT_FILE_PATH}
	echo "version=${FORMAT_FILE_VERSION}" >> ${FORMAT_FILE_PATH}
	echo "xattr=${FORMAT_USE_XATTR}" >> ${FORMAT_FILE_PATH}

	# create ID files

	if [ -n "${SERVER_NUMID}" ]; then
		echo " * Creating server numeric ID file: ${STORAGE_PATH}/${SERVER_NUMID_FILE}"
		echo "${SERVER_NUMID}" > "${STORAGE_PATH}/${SERVER_NUMID_FILE}"
	fi
}

# update config file (if enabled)
update_config_file()
{
	# check if config file is defined

	if [ -z "${CFG_PATH}" ]; then
		return 0
	fi

	echo "Updating config file: ${CFG_PATH}"

	if [ ! -f "${CFG_PATH}" ]; then
		echo " * ERROR: Config file not found: ${CFG_PATH}"
		exit 1
	fi

	if [ -n "${MGMTD_HOST}" ]; then
		echo " * Setting management host: ${MGMTD_HOST}"
		sed -i "s/\(^${MGMTD_CFG_KEY}.*=\).*/\1 ${MGMTD_HOST}/" ${CFG_PATH}
	fi

	if [ -n "${STORAGE_PATH}" ]; then
		echo " * Setting storage directory in config file..."
		sed -i "s|\(^${STORAGE_PATH_CFG_KEY}.*=\).*$|\1 ${STORAGE_PATH}|" ${CFG_PATH}
	fi

	if [ -n "${DISABLE_UNINITED_TARGETS}" ] && [ -n "${STORAGE_PATH}" ]; then
		echo " * Disabling usage of uninitialized storage directory in config file..."
		sed -i "s/\(^${ALLOW_INIT_CFG_KEY}.*=\).*/\1 false/" ${CFG_PATH}

		echo " * Fetching the underlying device..."
		DEVICE=$(df "${STORAGE_PATH}" | tail -n1 | cut -d\  -f1)
		echo "Underlying device detected: ${DEVICE}"
		echo "Fetching UUID of the file system on that device..."
		UUID=$(blkid -s UUID ${DEVICE} | cut -d= -f2 | sed "s/\"//g")
		echo "Found UUID ${UUID}"
		echo "Writing UUID to config file..."
		sed -i "s|\(^${FS_UUID_CFG_KEY}.*=\).*$|\1 ${UUID}|" ${CFG_PATH}

	fi

	if [ -n "${STORAGE_PATH}" ]; then
		echo " * Setting usage of extended attributes to: ${FORMAT_USE_XATTR}"
		sed -i "s/\(^${XATTR_CFG_KEY}.*=\).*/\1 ${FORMAT_USE_XATTR}/" ${CFG_PATH}
	fi
}

################## end of function definitions ##############


# configurable values and their defaults
# (for constants see above)

CFG_PATH="$DEFAULT_CFG_PATH" # empty path means "don't update cfg file"
FORCE_ACTIONS=""
FORMAT_USE_XATTR="true"
MGMTD_HOST=""
SERVER_NUMID=""
STORAGE_PATH=""
DISABLE_UNINITED_TARGETS="1"

# parse command line arguments
# (see print_usage() for description of parameters)

while getopts "Cc:fhm:p:S:s:ux" opt; do
        case $opt in
	C)
		CFG_PATH=""
		;;
	c)
		CFG_PATH="$OPTARG"
		;;
	f)
		FORCE_ACTIONS="1"
		;;
	h)
		print_usage
		exit 0
		;;
	m)
		MGMTD_HOST="$OPTARG"
		;;
	p)
		STORAGE_PATH="$OPTARG"
		;;
	S)
		echo "WARNING: The -S flag previously used to specify a string ID been deprecated and now has no effect. Starting in BeeGFS string IDs were replaced with aliases configured using BeeGFS CTL."
		;;
	s)
		SERVER_NUMID="$OPTARG"
		;;
	u)
		DISABLE_UNINITED_TARGETS=""
		;;
	x)
		FORMAT_USE_XATTR="false"
		;;
        *)
		echo "ERROR: Invalid argument" >&2
		print_usage
		exit 1
		;;
	esac
done

set -e

# don't do anything if no arguments are provided

if [ $# -eq 0 ]; then
	print_usage
	exit 1
fi

# make sure storage dir is defined

if [ -z "${STORAGE_PATH}" ]; then
	echo "ERROR: Storage directory is undefined." >&2
	echo
	print_usage
	exit 1
fi

# initialize storage directory

init_storage_dir

# update config file

update_config_file


echo "All done."