#!/bin/bash

##############################################################
#
# This script saves the main config directories and (if
# activated) saves them on the central syslog server.
#
# Hostname, additional folders and the syslog setting can be
# set in the config file '/etc/default/BackupServerConfig'.
#
##############################################################

set -ou pipefail

###########################################################
# Global systemd/journald Functions
###########################################################

function INFO {
	echo "$1"
	echo "$1" | systemd-cat -p info -t "$(basename "$0" .sh)"
}

function WARNING {
	echo "WARNING: $1" >&2
	echo "$1" | systemd-cat -p warning -t "$(basename "$0" .sh)"
}

function ERROR {
	echo "ERROR: $1" >&2
	echo "$1" | systemd-cat -p err -t "$(basename "$0" .sh)"
}

###########################################################

if [[ -r /etc/default/BackupServerConfig ]]; then
    source /etc/default/BackupServerConfig
fi

BACKUP_PATH=/var/backups
BACKUP_FILE="$(hostname -f).tar"
BACKUP_HOSTNAME=${BACKUP_HOSTNAME:-}
BACKUP_OBJ=${BACKUP_OBJ:-}
FTPHOST=${FTPHOST:-}

INFO "BackupServerConfig started..."

if [[ -n $BACKUP_HOSTNAME ]]; then
	BACKUP_FILE="$BACKUP_HOSTNAME.tar"
fi

INSTALLEDPACKAGES=$(mktemp)
dpkg --get-selections > "$INSTALLEDPACKAGES"

cd /tmp/ || exit 1
tar -cPf "$BACKUP_FILE" /etc
tar -rPf "$BACKUP_FILE" /root/.bashrc
tar -rPf "$BACKUP_FILE" /root/.ssh
tar -rPf "$BACKUP_FILE" --transform "s|$INSTALLEDPACKAGES|/installed_packages.txt|" "$INSTALLEDPACKAGES"
if [[ -n $BACKUP_OBJ ]]; then
	for BO in $BACKUP_OBJ; do
		tar --exclude=".git" -rPf "$BACKUP_FILE" "$BO"
	done
fi
gzip -9 -f "$BACKUP_FILE" && mv -f "$BACKUP_FILE.gz" $BACKUP_PATH
rm -f "$INSTALLEDPACKAGES"

if [[ -n "$FTPHOST" ]]; then
	if [[ -z "$GPGKEY" ]]; then
		ERROR "GPG key required for ftp server backup. Remote ftp backup aborted!"
		exit 1
	fi
	if [[ -z "$FTPDIR" ]]; then
		ERROR "FTP subdirectory required for ftp server backup. Remote ftp backup aborted!"
		exit 1
	fi
	TMP=$(gpg --quiet --list-keys --with-colons | grep "$GPGKEY")
	if [[ -z "$TMP" ]]; then
		ERROR "Public key for encryption of server configuration data not found. Remote ftp backup aborted!"
		exit 1
	fi

	cd $BACKUP_PATH || exit 1
	rm -f "$BACKUP_FILE.gz.gpg"
	gpg --quiet --encrypt -r "$GPGKEY" --trusted-key "$GPGKEY" "$BACKUP_FILE.gz"

	ftp -p -n "$FTPHOST" >/dev/null <<EOI
quote USER anonymous
quote PASS anonymous@anonymous.com
cd $FTPDIR
put "$BACKUP_FILE.gz.gpg"
quit
EOI
fi

INFO "BackupServerConfig successful"

exit 0