#!/bin/bash

#
# Bash script for creating backups of Nextcloud.
#
# Version 2.3.3
#
# Requirements:
#	- pigz (https://zlib.net/pigz/) for using backup compression. If not available, you can use another compression algorithm (e.g. gzip)
#
# Supported database systems:
# 	- MySQL/MariaDB
# 	- PostgreSQL
#
# Usage:
# 	- With backup directory specified in the script:  ./NextcloudBackup.sh
# 	- With backup directory specified by parameter: ./NextcloudBackup.sh <backupDirectory> (e.g. ./NextcloudBackup.sh /media/hdd/nextcloud_backup)
#
# The script is based on an installation of Nextcloud using nginx and MariaDB, see https://decatec.de/home-server/nextcloud-auf-ubuntu-server-20-04-lts-mit-nginx-mariadb-php-lets-encrypt-redis-und-fail2ban/
#

#
# IMPORTANT
# You have to customize this script (directories, users, etc.) for your actual environment.
# All entries which need to be customized are tagged with "TODO".
#

# Make sure the script exits when any command fails
set -Eeuo pipefail

# Variables
backupMainDir=${1:-} 

if [ -z "$backupMainDir" ]; then
	# TODO: The directory where you store the Nextcloud backups (when not specified by args)
	backupMainDir='/media/hdd/nextcloud_backup'
else
	backupMainDir=$(echo $backupMainDir | sed 's:/*$::')
fi

currentDate=$(date +"%Y%m%d_%H%M%S")

# The actual directory of the current backup - this is a subdirectory of the main directory above with a timestamp
backupDir="${backupMainDir}/${currentDate}"

# TODO: Use compression for file/data dir
# When this is the only script for backups, it's recommend to enable compression.
# If the output of this script is used in another (compressing) backup (e.g. borg backup), 
# you should probably disable compression here and only enable compression of your main backup script.
useCompression=true

# TOOD: The bare tar command for using compression.
# Use 'tar -cpzf' if you want to use gzip compression.
compressionCommand="tar -I pigz -cpf"

# TODO: The directory of your Nextcloud installation (this is a directory under your web root)
nextcloudFileDir='/var/www/nextcloud'

# TODO: The directory of your Nextcloud data directory (outside the Nextcloud file directory)
# If your data directory is located under Nextcloud's file directory (somewhere in the web root), the data directory should not be a separate part of the backup
nextcloudDataDir='/var/nextcloud_data'

# TODO: The directory of your Nextcloud's local external storage.
# Uncomment if you use local external storage.
#nextcloudLocalExternalDataDir='/var/nextcloud_external_data'

# TODO: The service name of the web server. Used to start/stop web server (e.g. 'systemctl start <webserverServiceName>')
webserverServiceName='nginx'

# TODO: Your web server user
webserverUser='www-data'

# TODO: The name of the database system (one of: mysql, mariadb, postgresql)
databaseSystem='mariadb'

# TODO: Your Nextcloud database name
nextcloudDatabase='nextcloud_db'

# TODO: Your Nextcloud database user
dbUser='nextcloud_db_user'

# TODO: The password of the Nextcloud database user
dbPassword='mYpAsSw0rd'

# TODO: The maximum number of backups to keep (when set to 0, all backups are kept)
maxNrOfBackups=0

# TODO: Ignore updater's backup directory in the data directory to save space
# Set to true to ignore the backup directory
ignoreUpdaterBackups=false

# File names for backup files
# If you prefer other file names, you'll also have to change the NextcloudRestore.sh script.
fileNameBackupFileDir='nextcloud-filedir.tar'
fileNameBackupDataDir='nextcloud-datadir.tar'

if [ "$useCompression" = true ] ; then
	fileNameBackupFileDir='nextcloud-filedir.tar.gz'
	fileNameBackupDataDir='nextcloud-datadir.tar.gz'
fi

fileNameBackupExternalDataDir=''

if [ ! -z "${nextcloudLocalExternalDataDir+x}" ] ; then
	fileNameBackupExternalDataDir='nextcloud-external-datadir.tar'

	if [ "$useCompression" = true ] ; then
		fileNameBackupExternalDataDir='nextcloud-external-datadir.tar.gz'
	fi
fi

fileNameBackupDb='nextcloud-db.sql'

# Function for error messages
errorecho() { cat <<< "$@" 1>&2; }

function DisableMaintenanceMode() {
	echo "$(date +"%H:%M:%S"): Switching off maintenance mode..."
	sudo -u "${webserverUser}" php ${nextcloudFileDir}/occ maintenance:mode --off
	echo "Done"
	echo
}

# Capture CTRL+C
trap CtrlC INT

function CtrlC() {
	read -p "Backup cancelled. Keep maintenance mode? [y/n] " -n 1 -r
	echo

	if ! [[ $REPLY =~ ^[Yy]$ ]]
	then
		DisableMaintenanceMode
	else
		echo "Maintenance mode still enabled."
	fi

	echo "Starting web server..."
	systemctl start "${webserverServiceName}"
	echo "Done"
	echo

	exit 1
}

#
# Print information
#
echo "Backup directory: ${backupMainDir}"

#
# Check for root
#
if [ "$(id -u)" != "0" ]
then
	errorecho "ERROR: This script has to be run as root!"
	exit 1
fi

#
# Check if backup dir already exists
#
if [ ! -d "${backupDir}" ]
then
	mkdir -p "${backupDir}"
else
	errorecho "ERROR: The backup directory ${backupDir} already exists!"
	exit 1
fi

#
# Set maintenance mode
#
echo "$(date +"%H:%M:%S"): Set maintenance mode for Nextcloud..."
sudo -u "${webserverUser}" php ${nextcloudFileDir}/occ maintenance:mode --on
echo "Done"
echo

#
# Stop web server
#
echo "$(date +"%H:%M:%S"): Stopping web server..."
systemctl stop "${webserverServiceName}"
echo "Done"
echo

#
# Backup file directory
#
echo "$(date +"%H:%M:%S"): Creating backup of Nextcloud file directory..."

if [ "$useCompression" = true ] ; then
	`$compressionCommand "${backupDir}/${fileNameBackupFileDir}" -C "${nextcloudFileDir}" .`
else
	tar -cpf "${backupDir}/${fileNameBackupFileDir}" -C "${nextcloudFileDir}" .
fi

echo "Done"
echo

#
# Backup data directory
#
echo "$(date +"%H:%M:%S"): Creating backup of Nextcloud data directory..."

if [ "$ignoreUpdaterBackups" = true ] ; then
	echo "Ignoring updater backup directory"

	if [ "$useCompression" = true ] ; then
		`$compressionCommand "${backupDir}/${fileNameBackupDataDir}"  --exclude="updater-*/backups/*" -C "${nextcloudDataDir}" .`
	else
		tar -cpf "${backupDir}/${fileNameBackupDataDir}"  --exclude="updater-*/backups/*" -C "${nextcloudDataDir}" .
	fi
else
	if [ "$useCompression" = true ] ; then
		`$compressionCommand "${backupDir}/${fileNameBackupDataDir}"  -C "${nextcloudDataDir}" .`
	else
		tar -cpf "${backupDir}/${fileNameBackupDataDir}"  -C "${nextcloudDataDir}" .
	fi
fi

echo "Done"
echo

#
# Backup local external storage.
#
if [ ! -z "${nextcloudLocalExternalDataDir+x}" ] ; then
	echo "$(date +"%H:%M:%S"): Creating backup of Nextcloud local external storage directory..."

	if [ "$useCompression" = true ] ; then
		`$compressionCommand "${backupDir}/${fileNameBackupExternalDataDir}"  -C "${nextcloudLocalExternalDataDir}" .`
	else
		tar -cpf "${backupDir}/${fileNameBackupExternalDataDir}"  -C "${nextcloudLocalExternalDataDir}" .
	fi

	echo "Done"
	echo
fi

#
# Backup DB
#
if [ "${databaseSystem,,}" = "mysql" ] || [ "${databaseSystem,,}" = "mariadb" ]; then
  	echo "$(date +"%H:%M:%S"): Backup Nextcloud database (MySQL/MariaDB)..."

	if ! [ -x "$(command -v mysqldump)" ]; then
		errorecho "ERROR: MySQL/MariaDB not installed (command mysqldump not found)."
		errorecho "ERROR: No backup of database possible!"
	else
		mysqldump --single-transaction -h localhost -u "${dbUser}" -p"${dbPassword}" "${nextcloudDatabase}" > "${backupDir}/${fileNameBackupDb}"
	fi

	echo "Done"
	echo
elif [ "${databaseSystem,,}" = "postgresql" ] || [ "${databaseSystem,,}" = "pgsql" ]; then
	echo "$(date +"%H:%M:%S"): Backup Nextcloud database (PostgreSQL)..."

	if ! [ -x "$(command -v pg_dump)" ]; then
		errorecho "ERROR: PostgreSQL not installed (command pg_dump not found)."
		errorecho "ERROR: No backup of database possible!"
	else
		PGPASSWORD="${dbPassword}" pg_dump "${nextcloudDatabase}" -h localhost -U "${dbUser}" -f "${backupDir}/${fileNameBackupDb}"
	fi
	
	echo "Done"
	echo
fi

#
# Start web server
#
echo "$(date +"%H:%M:%S"): Starting web server..."
systemctl start "${webserverServiceName}"
echo "Done"
echo

#
# Disable maintenance mode
#
DisableMaintenanceMode

#
# Delete old backups
#
if [ ${maxNrOfBackups} != 0 ]
then
	nrOfBackups=$(ls -l ${backupMainDir} | grep -c ^d)

	if [ ${nrOfBackups} -gt ${maxNrOfBackups} ]
	then
		echo "$(date +"%H:%M:%S"): Removing old backups..."
		ls -t ${backupMainDir} | tail -$(( nrOfBackups - maxNrOfBackups )) | while read -r dirToRemove; do
			echo "${dirToRemove}"
			rm -r "${backupMainDir}/${dirToRemove:?}"
			echo "Done"
			echo
		done
	fi
fi

echo
echo "DONE!"
echo "$(date +"%H:%M:%S"): Backup created: ${backupDir}"