#!/bin/sh

# Purpose {{{
##	This script will check if Ceph is available on the system.
##	And download all deb files of all Ceph related packages installed on the system
##		(eg. ceph, rbd, rados,…).
#
##	You can use this script in a cron (for periodic backup of Ceph packages) or directly.
# }}}

# Vars {{{
DEBUG=1

CEPH_DEB_PKG_DIR=$(mktemp --directory --tmpdir="/tmp" -- ceph-deb-files-XXXXXX.tmp)
CEPH_DEB_PKG_PATTERN="ceph|rados|rbd"

CEPH_VERSION=$(ceph version | cut -d" " -f3)

BKP_DIR="/srv/ceph"
BKP_TAR_PATH="${BKP_DIR}/ceph-deb_${CEPH_VERSION}-$(date +%Y%m%d).tar"

EXISTENT_BACKUP_TAR="$(find "${BKP_DIR}" -type f -iname "ceph-deb_${CEPH_VERSION}*")"
# }}}

# If Ceph is installed on the system
if [ "$(command -v ceph)" ]; then

	# and no backup of this version already exists
	if [ ! "${EXISTENT_BACKUP_TAR}" ]; then
		## Ensure to create backup directory
		mkdir -p -- "${BKP_DIR}"

		## Create and go to a temp directory
		cd -- "${CEPH_DEB_PKG_DIR}" > /dev/null || exit 2

		## Download deb files of all ceph related packages installed on the system
		[ "${DEBUG}" -eq "0" ] && printf '%b\n' "Download deb files of all ceph related packages installed on the system."
		## Use aptitude before Debian Stretch because apt doesn't yet know "download" action
		if [ "$(cat /etc/debian_version | cut -c1)" -lt "9" ]; then
			aptitude download -- $(dpkg -l | awk -v pattern="${CEPH_DEB_PKG_PATTERN}" '$0~pattern {print $2"="$3}') || exit 3
		else
			apt download -- $(dpkg -l | awk -v pattern="${CEPH_DEB_PKG_PATTERN}" '$0~pattern {print $2"="$3}') || exit 3
		fi

		[ "${DEBUG}" -eq "0" ] && printf '%b\n' "Backup Ceph deb files in version : ${CEPH_VERSION}"
		tar cf "${BKP_TAR_PATH}" ./*.deb > /dev/null 2>&1 || exit 4

		## Remove deb files
		rm -rf -- *.deb

		cd - > /dev/null || exit 2

		## Remove temp directory
		rmdir -- "${CEPH_DEB_PKG_DIR}"
	else
		[ "${DEBUG}" -eq "0" ] && printf '%b\n' "A backup of this version already exists : ${EXISTENT_BACKUP_TAR}"
		exit 0
	fi

else
		[ "${DEBUG}" -eq "0" ] && printf '%b\n' "Ceph doesn't seems to be available. Please take a look on \`ceph version\` command"
	exit 1
fi

exit 0