#!/bin/bash
################################################################################
# backup_remote.sh
# create @17.04.17
################################################################################

. /path/to/utils.sh


##
# settings
#
LIST_DIR='/path/to/backup.d'

LIST_EXT='.list'

DEST_DIR='/path/to/dest'

LOG_DIR='/var/log/rsync'

SSH_USER='collector'

SSH_PRIVKEY='/path/to/id_ed25519'

RSYNC_CMD='/usr/bin/rsync'

RSYNC_DEFOPTS='--delete --exclude lost+found'

##
# check variables.
#
if [ ! -f "${RSYNC_CMD}" ] || [ ! -x "${RSYNC_CMD}" ]; then
        error "'${RSYNC_CMD} is not executable."
        exit 1
fi

if [ ! -d "${LIST_DIR}" ] || [ ! -x "${LIST_DIR}" ]; then
        error "Cannot access to '${LIST_DIR}'."
        exit 1
fi

if [ ! -f "${SSH_PRIVKEY}" ] || [ ! -r "${SSH_PRIVKEY}" ]; then
        error "Cannot access to '${SSH_PRIVKEY}'."
        exit 1
fi

if [ ! -d "${DEST_DIR}" ] || [ ! -w ${DEST_DIR} ]; then
        error "Cannot access to '${DEST_DIR}'."
        exit 1
fi

if [ ! -d "${LOG_DIR}" ] || [ ! -w ${LOG_DIR} ]; then
        error "Cannot access to '${LOG_DIR}'."
        exit 1
fi


##
# check argument
#
if [ -z "$1" ]; then
        error "usage: ${0} <hostname>"
        exit 1
fi

HOST=${1}

if [ "${HOST}" = 'local' ]; then
        error "Not acceptable hostname '${HOST}'."
        exit 1
fi

FILE="${LIST_DIR}/${HOST}${LIST_EXT}"

if [ ! -f "${FILE}" ] && [ ! -r "${FILE}" ]; then
        error "Cannot access to '${FILE}'."
        exit 1
fi

##
# start main.
#
LOG_FILE="${LOG_DIR}/${HOST}.$(date +%Y-%m-%d-%H.%M.%S).log"

RET=0

info "Backup start."
info "Rsync log is ${LOG_FILE}"

while read DIR OPTS; do

        # skip blank line.
        if [[ "${DIR}" =~ ^\s*$ ]]; then
                continue
        fi

        # skip comment line.
        if [[ "${DIR}" =~ ^\s*# ]]; then
                continue
        fi

        if [[ "${DIR}" =~ [^/]$ ]]; then
                warn "Directory path should ends with '/'."
                DIR="${DIR}/"
        fi

        SRC="${HOST}:${DIR}"
        DST="${DEST_DIR}/${HOST}${DIR}"

        # create directory tree
        /bin/mkdir -p ${DST}

        if [ $? -ne 0 ]; then
                error "Cannot create directory: '${DST}'."
                RET=2
                continue
        fi

        info "Start sync from '${SRC}' to '${DST}'."

        ${RSYNC_CMD} -avvr \
                --rsh "ssh -l ${SSH_USER} -i ${SSH_PRIVKEY} -o strictHostKeyChecking=no" \
                --rsync-path="sudo rsync" \
                ${RSYNC_DEFOPTS} ${OPTS} \
                ${SRC} ${DST} \
                >> ${LOG_FILE} 2>&1

        if [ $? -ne 0 ]; then
                error "Failed to rsync from '${SRC}' to '${DST}': $!"
                RET=3
        else
                info "Succeeded to rsync from '${SRC}' to '${DST}'."
        fi

done < ${FILE}


info "Backup finished."

exit ${RET}