#!/bin/sh

## $Id: 223.backup-zfs.sh 58697be4119d 2017-10-03 03:09 +0200 lachman $
## Created by: Miroslav Lachman <000.fbsd@quip.cz>

## Backup of zpool info, zfs list and zfs properties for each filesystem.
## Data are stored on local filesystem, in /var/backup.
## It is recommended to copy those files to off-site storage.


## If there is a global system configuration file, suck it in.
##
if [ -r /etc/defaults/periodic.conf ]
then
	. /etc/defaults/periodic.conf
	source_periodic_confs
fi

bak_dir=/var/backups

rotate() {
	base_name=$1
	show_diff=$2
	file="$bak_dir/$base_name"

	if [ -f "${file}.bak" ] ; then
		rc=0
		if cmp -s "${file}.bak" "${file}.tmp"; then
			rm "${file}.tmp"
		else
			rc=1
			[ -n "$show_diff" ] && diff "${file}.bak" "${file}.tmp"
			mv "${file}.bak" "${file}.bak2" || rc=3
			mv "${file}.tmp" "${file}.bak" || rc=3
		fi
	else
		rc=1
		mv "${file}.tmp" "${file}.bak" || rc=3
		[ -n "$show_diff" ] && cat "${file}.bak"
	fi
}

case "$daily_backup_zfs_verbose" in
	[Yy][Ee][Ss]) show="YES"
esac

case "$daily_backup_zfs_enable" in
	[Yy][Ee][Ss])

	zpools=$(zpool list -vp | sed -E 's/^([ ]*[\./[:alnum:]]+ +[\.[:alnum:]-]+) .*/\1/')

	if [ -z "$zpools"  ]; then
		echo '$daily_backup_zfs_enable is set but no zpools found.'
		rc=2
	else
		echo ""
		echo "Backup of ZFS informations for all imported pools";

		echo "$zpools" > "$bak_dir/zpool_info.tmp"
		rotate "zpool_info" $show

		zfs list -p -H -o name,mountpoint > "$bak_dir/zfs_list.tmp"
		rotate "zfs_list" $show

		: ${daily_backup_zfs_props_enable="YES"}
		case "$daily_backup_zfs_props_enable" in
			[Yy][Ee][Ss])
			zfs get -H -p -t filesystem,volume all |
			grep -E -v "available|compressratio|logicalreferenced|logicalused|refcompressratio|referenced|used|usedbychildren|usedbydataset|written" > "$bak_dir/zfs_props.tmp"
			rotate "zfs_props"

			zpool get -H -p all |
			grep -E -v "capacity|dedupratio|free|allocated|fragmentation" > "$bak_dir/zpool_props.tmp"
			rotate "zpool_props"
			;;
		esac
	fi
	;;
	*)  rc=0;;
esac

exit $rc