entrypoint

#!/bin/bash

DEBUG=${DEBUG:-}
if [ x"$DEBUG" = x"ECHO" ] ; then
   set -x
fi

set -e

#
# Backup Mode. Possible values:
# - SIMPLE: Create ${TARGET_PREFIX}/${DATE}
# - FULL: Create ${TARGET_PREFIX}/full-${DATE}
# - INCREMENTAL: Create ${TARGET_PREFIX}/full-{LASTDATE}-inc-${DATE} based on the last full-${DATE}
#
BACKUP_MODE="${BACKUP_MODE:-SIMPLE}"
RUN_EVERY="${RUN_EVERY:-}"
RESTORE_STACK="${RESTORE_STACK:-}"
RANCHER_URL="${RANCHER_URL:-}"
RANCHER_ACCESS_KEY="${RANCHER_ACCESS_KEY}"
RANCHER_SECRET_KEY="${RANCHER_SECRET_KEY}"
BACKUP_VOLUME="${BACKUP_VOLUME:-}"
BACKUP_DRIVER="${BACKUP_DRIVER:-}"
STORAGEBOX_URL="${STORAGEBOX_URL:-}"
STORAGEBOX_USER="${STORAGEBOX_USER:-}"
STORAGEBOX_PASSWORD="${STORAGEBOX_PASSWORD:-}"
MYSQL_PASSWORD="${MYSQL_PASSWORD:-}"
MYSQL_HOST="${MYSQL_HOST:-}"
MYSQL_PORT="${MYSQL_PORT}"
RANCHER_CLI_VERSION="${RANCHER_CLI_VERSION:-v0.4.1}"
KEEP_BACKUPS="${KEEP_BACKUPS:-4}"

BACKUP_DIRECTORY="/target"
DATA_DIRECTORY="/var/lib/mysql"

#
# Find the directory name of the latest full backup
#
find_last_full_backup() {
	FILES=( $(ls -d "${BACKUP_DIRECTORY}/"full-????-??-??-??????) )

	basename ${FILES[-1]}

	return
}

download_rancher_compose() {

	RANCHER_COMPOSE_VERSION="$1"

	if [ -z "${RANCHER_COMPOSE_VERSION}" ] ; then
		RANCHER_COMPOSE_VERSION="0.12.2"
	fi

	RANCHER_COMPOSE="rancher-compose-${RANCHER_COMPOSE_VERSION}"
	TARGET_RANCHER_COMPOSE="/usr/local/bin/$RANCHER_COMPOSE"
	if [ ! -f "$TARGET_RANCHER_COMPOSE" ] ; then
		echo "rancher-compose version $RANCHER_COMPOSE_VERSION not found. Downloading."
		curl "https://releases.rancher.com/compose/v${RANCHER_COMPOSE_VERSION}/rancher-compose-linux-amd64-v${RANCHER_COMPOSE_VERSION}.tar.gz" \
			| gunzip | tar -C /tmp -x
		cp /tmp/rancher-compose-v${RANCHER_COMPOSE_VERSION}/rancher-compose "$TARGET_RANCHER_COMPOSE"
		chmod +x "$TARGET_RANCHER_COMPOSE"
		echo "Installed Rancher compose $RANCHER_COMPOSE_VERSION to $TARGET_RANCHER_COMPOSE"
	fi

	return
}

retrieveDockerCompose() {

	BACKUP_NAME="$1"

	cd /tmp/
	curl -o /tmp/docker-compose.yml.tpl http://rancher-metadata/2015-12-19/self/service/metadata/docker-compose

	ALPHANUM_TARGET_BACKUP=$(echo ${BACKUP_NAME} | sed -e 's/[^a-zA-Z0-9\-]//g')
	sed \
		-e "s~%%BACKUP%%~$BACKUP_NAME~" \
		-e "s~%%BACKUP_ALPHANUM%%~$ALPHANUM_TARGET_BACKUP~" \
		-e "s~%%RANCHER_URL%%~${RANCHER_URL}~" \
		-e "s~%%RANCHER_KEY%%~${RANCHER_ACCESS_KEY}~" \
		-e "s~%%RANCHER_SECRET%%~${RANCHER_SECRET_KEY}~" \
		-e "s~%%BACKUP_VOLUME%%~${BACKUP_VOLUME}~" \
		-e "s~%%BACKUP_DRIVER%%~${BACKUP_DRIVER}~" \
		-e "s~%%STORAGEBOX_URL%%~${STORAGEBOX_URL}~" \
		-e "s~%%STORAGEBOX_USER%%~${STORAGEBOX_USER}~" \
		-e "s~%%STORAGEBOX_PASSWORD%%~${STORAGEBOX_PASSWORD}~" \
	  	/tmp/docker-compose.yml.tpl > /tmp/docker-compose.yml

	return
}

createRestoreService() {

	BACKUP_NAME="$1"

	if [ -z "${RESTORE_STACK}" ] ; then
		echo "RESTORE_STACK environment variable not set, not creating a restore service"
		return
	fi

	echo "======================================================================"
	echo "= Creating restore service for $BACKUP_NAME"
	echo "======================================================================"
	echo ""

	OLDDIR=$(pwd)

	retrieveDockerCompose "${BACKUP_NAME}"

	download_rancher_compose ${RANCHER_COMPOSE_VERSION}

	echo "Using ${RANCHER_COMPOSE} as rancher-compose executable"
	${RANCHER_COMPOSE} -p "${RESTORE_STACK}" create

	cd "$OLDDIR"

	return
}

removeRestoreService() {

	BACKUP_NAME="$1"

	if [ -z "${RESTORE_STACK}" ] ; then
		echo "RESTORE_STACK environment variable not set, not removing a restore service"
		return
	fi

	echo "======================================================================"
	echo "= Removing restore service for ${BACKUP_NAME}"
	echo "======================================================================"
	echo ""

	OLDDIR=$(pwd)

	cd /tmp/

	retrieveDockerCompose "${BACKUP_NAME}"
	download_rancher_compose ${RANCHER_COMPOSE_VERSION}

	echo "Using ${RANCHER_COMPOSE} as rancher-compose executable"
	#
	# This will not remove the whole stack as a custom docker-compose.yml is written with only this service in it
	#
	${RANCHER_COMPOSE} -p "${RESTORE_STACK}" rm

	cd "$OLDDIR"

	return
}

setDefaults() {
	if [ -z "${MYSQL_USER}" ] ; then
		echo "WARNING: Running with default user."
	else
		echo "Connecting as ${MYSQL_USER}"
		USER=(--user "${MYSQL_USER}")
	fi

	if [ -z "${MYSQL_PASSWORD}" ] ; then
		echo "WARNING: Running without password."
	else
		echo "Connecting with password"
		PASSWORD=(--password "${MYSQL_PASSWORD}")
	fi

	if [ -z "${MYSQL_HOST}" ] ; then

		echo "WARNING: Connecting to default host 'source', make sure to set links"
		MYSQL_HOST="target"
	else
		echo "Connecting to host $MYSQL_HOST"
	fi

	if [ -z "$MYSQL_PORT" ] ; then
		MYSQL_PORT="3306"
		echo "WARNING: Connecting to default port '3306'"
	else
		echo "Connecting to port $MYSQL_PORT"
	fi

	return
}

backupRancher() {

	echo "Backing up rancher stack"

	local METADATA_URL="http://rancher-metadata/2015-07-25"
	local STACK=$(curl -s $METADATA_URL/self/service/links | sed 's/%2F.*//')
	local SERVICE=$(curl -s $METADATA_URL/self/service/links | sed 's/[^%]*%2F//')
	local TARGET_DIRECTORY="$1"

	if [ -z "$RANCHER_URL" -o -z "$RANCHER_ACCESS_KEY" -o -z "$RANCHER_SECRET_KEY" ] ; then
		echo "No rancher access data set, not backing up {docker,rancher}-compose.yml files"
		return
	fi

	RANCHER_CLI_DIRECTORY="/opt/rancher/${RANCHER_CLI_VERSION}"
	if [ ! -d "$RANCHER_CLI_DIRECTORY" ] ; then
		mkdir -p "$RANCHER_CLI_DIRECTORY"
	fi

	if [ ! -f "$RANCHER_CLI_DIRECTORY/rancher" ] ; then
		echo "Downloading rancher cli $RANCHER_CLI_VERSION"
		curl -s "https://releases.rancher.com/cli/${RANCHER_CLI_VERSION}/rancher-linux-amd64-${RANCHER_CLI_VERSION}.tar.gz" \
			| tar xvz -C "$RANCHER_CLI_DIRECTORY" --strip-components=2
	fi

	$RANCHER_CLI_DIRECTORY/rancher export "${STACK}"
	cp ${STACK}/{docker,rancher}-compose.yml "${TARGET_DIRECTORY}/"
	echo "{\"stack\":\"${STACK}\",\"service\":\"${SERVICE}\"}" > "${TARGET_DIRECTORY}/backup.json"

	return
}

usage() {
	echo "======================================================================"
	echo "= Usage"
	echo "======================================================================"
	echo "docker run ipunktbs/xtrabackup -v "name-backup-directory:${BACKUP_DIRECTORY}" [COMMAND]"
	echo ""
	echo "The ipunktbs/xtrabackup docker image tries to provide percona xtrabackup for use in rancher environments"
	echo ""


	echo "======================================================================"
	echo "= Commands"
	echo "======================================================================"
	echo "- backup"
	echo "  Does a backup, prepare, prepare cycle from /var/lib/mysql to ${BACKUP_DIRECTORY}/YY-mm-dd-HH_ii"
	echo "  If the environment variable RUN_EVERY is set then backups will continue to be made, with"
	echo " 'sleep \$RUN_EVERY' in between"
	echo ""
	echo "- restore YY-mm-dd-HH_ii"
	echo "  Does a copy-back ${BACKUP_DIRECTORY}/YY-mm-dd-HH_ii to /var/lib/mysql"
	echo ""
	echo "- run COMMAND"
	echo "  Runs the given command within the container."

	exit 0
}

backup() {

	RUNNING="true"
	while [ x"$RUNNING" = x"true" ] ; do

		DATE=$(date '+%Y-%m-%d-%H%M%S')
		BACKUP_NAME="${DATE}"

		if [ x"${BACKUP_MODE}" = x"FULL" ] ; then
			echo "======================================================================"
			echo "= Full backup process"
			echo "======================================================================"
			echo ""

			BACKUP_NAME="full-${DATE}"
		fi

		if [ x"${BACKUP_MODE}" = x"INCREMENTAL" ] ; then
			echo "======================================================================"
			echo "= Incremental backup process"
			echo "======================================================================"
			echo ""
			BASE_BACKUP_NAME="$(find_last_full_backup)"
			BASE_BACKUP_PATH="${BACKUP_DIRECTORY}/${BASE_BACKUP_NAME}"
			BACKUP_NAME="${BASE_BACKUP_NAME}-inc-$DATE"
			echo "Base backup: ${BASE_BACKUP_NAME}"
			echo ""
		fi

		BACKUP_PATH="${BACKUP_DIRECTORY}/$BACKUP_NAME"

		echo "======================================================================"
		echo "= Starting backup process to $BACKUP_PATH"
		echo "======================================================================"
		echo ""

		setDefaults

		if [ ! -d "$BACKUP_PATH" ] ; then
			echo "$BACKUP_PATH does not exist yet, creating"
			mkdir -p "$BACKUP_PATH"
		fi

		echo "Creating backup in $BACKUP_PATH"

		backupRancher $BACKUP_PATH

		if [ x"${BACKUP_MODE}" = x"INCREMENTAL" ] ; then
			# Backup - copies innodb files and reads binary log while doing so
			xtrabackup --backup --datadir="$DATA_DIRECTORY" \
				--incremental-basedir="${BASE_BACKUP_PATH}" \
				--target-dir="$BACKUP_PATH" ${USER[@]} ${PASSWORD[@]} \
				--host "${MYSQL_HOST}" --port ${MYSQL_PORT}
		else
			# Backup - copies innodb files and reads binary log while doing so
			xtrabackup --backup --datadir="$DATA_DIRECTORY" \
				--target-dir="$BACKUP_PATH" ${USER[@]} ${PASSWORD[@]} \
				--host "${MYSQL_HOST}" --port ${MYSQL_PORT}
		fi

		if [ x"${BACKUP_MODE}" = x"SIMPLE" ] ; then
			echo "Mode is SIMPLE, preparing backups"

			# First prepare - selfheal innodb and apply binary log to make it consistent
			xtrabackup --prepare --target-dir="$BACKUP_PATH"
			# Second prepare - write logfiles for faster server startup
			xtrabackup --prepare --target-dir="$BACKUP_PATH"
		fi
		echo "$BACKUP_PATH Done"

		createRestoreService "$BACKUP_NAME"

		if [ ! -z "${RUN_EVERY}" ] ; then

			echo "Sleeping for ${RUN_EVERY} before starting again"
			sleep "${RUN_EVERY}"

		else

			echo "Environment variable RUN_EVERY was not set, not looping"
			RUNNING="false"

		fi


	done

	exit 0
}

#
# Input:
# - $1 Incremental Backup directory
# Output:
# - Full backup which is the base of the incremental backup
#
parse_full_backup_base() {
	sed 's~^\(full-[0-9][0-9][0-9][0-9]-[0-9][0-9]-[0-9][0-9]-[0-9][0-9][0-9][0-9][0-9][0-9]\).*~\1~' <<< "$1"
	return
}

#
# Parameter
# $1 - TARGET_PREFIX - The prefix(directory) in which the NAME directory lies
# $2 - NAME - The name of the backup to be restored
# $3 - RESTORE_DIRECTORY - the temporary directory in which the backup should be restored
#
#
restore_incremental() {

	local BACKUP_DIRECTORY="$1"
	local BACKUP_NAME="$2"
	local RESTORE_DIRECTORY="$3"
	local BACKUP_PATH="${BACKUP_DIRECTORY}/${BACKUP_NAME}"
	local BACKUP_INCREMENT_PATH="/tmp/${BACKUP_NAME}-inc1"

	echo "======================================================================"
	echo "= Incremental full backup ${BACKUP_PATH}"
	echo "======================================================================"
	echo ""


	BASE_BACKUP_NAME="$(parse_full_backup_base ${BACKUP_NAME})"

	BASE_BACKUP_PATH="${BACKUP_DIRECTORY}/${BASE_BACKUP_NAME}"

	# Copy the full backup - preparing incremental backups would otherwise overwrite the full backup
	if [ ! -d "${BASE_BACKUP_PATH}" ] ; then
		echo "E> Base backup ${BASE_BACKUP_PATH} does not exist. Aborting."
		exit 1
	fi

	echo "Copying full backup"
	cp -Rfv "${BASE_BACKUP_PATH}" "${RESTORE_DIRECTORY}"

	#
	# Copying the incremental backup. Xtrabackup accesses a lot of files at the same time. Backups are usually on a slow
	# medium which might not allow such access
	#
	echo "Copying incremental Backup"
	cp -Rfv "${BACKUP_PATH}" "${BACKUP_INCREMENT_PATH}"

	# Prepare the full backup
	echo "Preparing ${BASE_BACKUP_NAME}"
	xtrabackup --prepare --apply-log-only --target-dir="$RESTORE_DIRECTORY"

	# apply the incremental backup
	echo "Preparing ${BACKUP_NAME}"
	xtrabackup --prepare --target-dir="$RESTORE_DIRECTORY" --incremental-dir="${BACKUP_INCREMENT_PATH}"

	echo "Done preparing"
	# copying back the prepared directory to the data directory is done in restore() as it is a shared step

	return
}


#
# Restore a full backup
#
restore_full() {

	local BACKUP_DIRECTORY="$1"
	local BACKUP_NAME="$2"
	local RESTORE_DIRECTORY="$3"
	local BACKUP_PATH="${BACKUP_DIRECTORY}/${BACKUP_NAME}"

	echo "======================================================================"
	echo "= Restoring full backup ${BACKUP_PATH}"
	echo "======================================================================"
	echo ""

	# Copy the backup to a temporary restore directory. Otherwise the the backup would be prepared and it would no longer
	# be possible to use it as base to restore incremental backups
	cp -Rfv "${BACKUP_PATH}" "${RESTORE_DIRECTORY}"

	# Prepare the backup
	xtrabackup --prepare --target-dir="$RESTORE_DIRECTORY"

	# copying back the prepared directory to the data directory is done in restore() as it is a shared step

	return
}

#
# Restore $1
#
# Parameter
# $1 - BACKUP_DIRECTORY
# $2 - BACKUP_NAME
#
#
restore() {

	local BACKUP_DIRECTORY="$1"
	local BACKUP_NAME="$2"
	local BACKUP_PATH="${BACKUP_DIRECTORY}/${BACKUP_NAME}"

	echo "======================================================================"
	echo "= Starting restore process from ${BACKUP_PATH}"
	echo "======================================================================"
	echo ""

	if [ -z "$BACKUP_NAME" ] ; then

		usage

		echo "E> Error: no target backup given to"
		exit 1
	fi

	if [ ! -d "${BACKUP_PATH}" ] ; then
		echo "E> Directory '${BACKUP_PATH}' does not exist. Backup restore failed."
		exit 2
	fi

	# Create the TEMPORARY_RESTORE_PATH and make sure it is empty
	TEMPORARY_RESTORE_PATH="/tmp/${BACKUP_NAME}"
	if [ -d "${TEMPORARY_RESTORE_PATH}" ] ; then
		echo "Restore directory ${TEMPORARY_RESTORE_PATH} already exists. Deleting"
		rm -Rf "${TEMPORARY_RESTORE_PATH}"
	fi

	local REGEX='^full-.*-inc-.*'
	if [[ "${BACKUP_NAME}" =~ $REGEX ]] ; then
		restore_incremental "$BACKUP_DIRECTORY" "$BACKUP_NAME" "${TEMPORARY_RESTORE_PATH}"
	else
		restore_full "$BACKUP_DIRECTORY" "${BACKUP_NAME}" "${TEMPORARY_RESTORE_PATH}"
	fi

	# Copy back the prepared data
	xtrabackup --copy-back --datadir="$DATA_DIRECTORY" --target-dir="${TEMPORARY_RESTORE_PATH}"
	echo "Done"

	exit 0
}

get_backup_date() {
	local BACKUP_NAME="$1"

	sed 's~full-\([0-9][0-9][0-9][0-9]-[0-9][0-9]-[0-9][0-9]\)-[0-9][0-9][0-9][0-9][0-9][0-9]~\1~' <<< "${BACKUP_NAME}"

	return
}

cleanup() {
	echo "======================================================================"
	echo "= Starting cleanup process"
	echo "======================================================================"
	echo ""

	IFS='
'
	local FULL_BACKUPS=( $(find "${BACKUP_DIRECTORY}" -mindepth 1 -maxdepth 1 -name 'full-????-??-??-??????' -printf '%f\n' | sort -d -r) )
	local NUM_FULL_BACKUPS="${#FULL_BACKUPS[@]}"
	echo "Found ${NUM_FULL_BACKUPS} full backups"
	echo "Keeping ${KEEP_BACKUPS} backups"
	if [ "${NUM_FULL_BACKUPS}" -le "${KEEP_BACKUPS}" ] ; then
		echo "No more than ${KEEP_BACKUPS} full backups found."
		echo "Exiting."
		exit 0
	fi

	index="${KEEP_BACKUPS}"
	while [ "$index" -lt "${NUM_FULL_BACKUPS}" ] ; do
		local BACKUP_NAME="${FULL_BACKUPS[$index]}"
		echo "Removing $index: ${BACKUP_NAME}"
		remove ${BACKUP_NAME}
		index=$(( ++index ))
	done


	return
}

#
# Remove the full backup given as $1, all its incremental backups and their respective services.
#
remove() {
	local FULL_BACKUP="$1"

	echo "Removing:"
	ls -d "${BACKUP_DIRECTORY}/${FULL_BACKUP}"*

	for BACKUP_PATH in "${BACKUP_DIRECTORY}/${FULL_BACKUP}"* ; do
		local BACKUP_NAME="$(basename $BACKUP_PATH)"

		echo "Removing ${BACKUP_NAME} in ${BACKUP_PATH}"

		removeRestoreService "${BACKUP_NAME}"

		rm -Rf "${BACKUP_PATH}"
	done
}

case $1 in
	backup)

		backup
	;;
	restore)

		shift
		restore "${BACKUP_DIRECTORY}" $1

		;;
	create)
		shift
		BACKUP_PATH="$1"

		echo "======================================================================"
		echo "= Creating restore service from $BACKUP_PATH"
		echo "======================================================================"
		echo ""

		createRestoreService "$BACKUP_PATH"
		;;

	clear)
		echo "======================================================================"
		echo "= Starting clear process for /var/lib/mysql"
		echo "======================================================================"
		echo ""

		if [ "$2" != "yes" ] ; then
			echo "Clearing not confirmed. Please add 'yes' as parameter"
			echo "Example: docker run ipunktbs/xtrabackup clear yes"
			exit 1
		fi

		echo "Clearing confirmed, starting"
		rm -Rfv /var/lib/mysql/*
		echo "Done"
		;;
	cleanup)
		echo "======================================================================"
		echo "= Clean up expired backups from ${BACKUP_PATH}"
		echo "======================================================================"
		echo ""

		cleanup
		exit 0
		;;
	run)
		shift

		echo "======================================================================"
		echo "= Starting command $*"
		echo "======================================================================"
		echo ""

		$*
		echo "Done"
		exit 0
		;;
	remove)

		shift
		echo "======================================================================"
		echo "= Removing backup $1"
		echo "======================================================================"
		echo ""

		if [ -z "$1" ] ; then
			echo "Missing argument: Backup to remove"
			exit 1
		fi

		remove $1
		;;
	help)
		shift
		usage
		exit 0
		;;
	*)
		usage
		exit 0
		;;
esac