#!/bin/bash
#Backupskript - Backup with rsync and ssh
#Version: 0.1. (2019-12-17)
#
### Konfigurationen
## Ordner müssen mit / enden.
#Verzeichnis des Skriptes finden
PFAD=$(dirname "$(readlink -e "$0")");
HOST=`hostname`;

#SSH (key file based login required)
SSH_TARGET="domain.local";
SSH_USER="sshuser";
SSH_DIR="/directory/";

#Ursprungsverzeichnis des Backup
SOURCE=(` cat "${PFAD}/backup_dirs.conf" `);

#Pfad zu Datei mit auszuschließenden Dateien/Ordnern
EXCLUDE=${PFAD}"/backup_excl.conf";

#Pfad zu Logdatei
LOG_FILE=${PFAD}"/backup_ext_"${HOST}".log";

#Pfad zu Lock-Datei
LOCK_FILE=${PFAD}"/backup_ext_"${HOST}".lock";

###Skript beginnt, unterhalb dieser Zeile nichts ändern
NOW_START=$(/bin/date +%Y%m%d-%H%M%S);

##Test Log/Lock-Datei
if [ -e ${LOCK_FILE} ]; then
 NOW_MSG=$(/bin/date +%Y%m%d-%H%M%S);
 `echo ${NOW_MSG}": Backup läuft bereits. Breche ab." >> ${LOG_FILE}`;
 unset NOW_MSG;
 exit;
else
 touch ${LOCK_FILE};
fi

if [ ! -f ${LOG_FILE} ];then
 touch ${LOG_FILE};
fi

##Funktionen
#Log und Notify-Nachricht
notify_log() {
 NOW_MSG=$(/bin/date +%Y%m%d-%H%M%S);
 if [ "${LOG_FINISH}" ]; then
  `echo ${NOW_MSG}": "${NOTIFY_LOG_MSG} | mail -s "[VOLMAR]: Backup nach nc.hw12.org erfolgreich" tba@timaba.de`;
 unset LOG_FINISH;
 fi
`echo ${NOW_MSG}": "${NOTIFY_LOG_MSG} >> ${LOG_FILE}`;
 unset NOTIFY_LOG_MESSAGE;
 unset NOW_MSG;
}

#Lock-Datei löschen und Skript beenden
lock_delete_end() {
 rm ${LOCK_FILE};
 exit;
}

#Prüfen ob bereits Backups existieren
SSH_LOGIN="${SSH_USER}@${SSH_TARGET}";
if [ "${SSH_DIR}" ]; then
 LASTBACKUP=`ssh ${SSH_LOGIN} ls -d ${SSH_DIR}[[:digit:]]* | /usr/bin/sort -r | /usr/bin/head -1 `;
 NOTIFY_LOG_MSG="Letztes Backup [${SSH_TARGET}]: "${LASTBACKUP};
 notify_log;
fi

# Hardlinks definieren, wenn vorheriges Backup gefunden.
if [ "${LASTBACKUP}" ]; then
 INC="--link-dest="${LASTBACKUP};
fi

#Neuen Ordner anlegen
`ssh ${SSH_LOGIN} mkdir -p ${SSH_DIR}${NOW_START}`;

##rsync
EXCLUDIRS="--exclude-from="${EXCLUDE};
for SOURCE in "${SOURCE[@]}"
do
START_BACKUP="rsync ${EXCLUDIRS} ${INC} -avze ssh ${SOURCE[@]} ${SSH_LOGIN}:${SSH_DIR}${NOW_START} ";
`echo ${START_BACKUP}`;
done

NOTIFY_LOG_MSG="Backup beendet.";
LOG_FINISH="1";
notify_log;
lock_delete_end;