#!/bin/sh

# Little check for device errors on Btrfs volumes
#
# GPL v3+ (copyright chl-dev@bugness.org)

PROGPATH=$( echo $0 | sed -e 's,[\\/][^\\/][^\\/]*$,,' )
REVISION="0.1"

# Stop at the first non-catched error
set -e

# Include check_range()
# Not needed at the moment
#. $PROGPATH/utils.sh
STATE_OK=0
STATE_WARNING=1
STATE_CRITICAL=2
STATE_UNKNOWN=3
STATE_DEPENDENT=4

# Default values
WARNING_STATS=0
CRITICAL_STATS=0

# Output
OUTPUT_EXIT_STATUS=$STATE_OK
OUTPUT_DETAIL_OK=""
OUTPUT_DETAIL_WARNING=""
OUTPUT_DETAIL_CRITICAL=""
OUTPUT_PERFDATA=""
NB_DEVICES=0

#
# Help function
#
usage() {
	cat <<EOF
Usage :
  $0 -V volume -V...

Example :
  ./check_btrfs.sh -V /home
EOF
}

check_range_syntax() {
	return 0
}
#	check_range 0 "$1" >/dev/null 2>&1
#	if [ "$?" -eq "2" ]; then
#		return 1

# Some early checks
if ! which btrfs 2>&1 >/dev/null; then
	echo "UNKNOWN 'btrfs' command not found."
	exit $STATE_UNKNOWN
fi

#
# Loop on parameters + tests
#
while getopts hw:c:V: f; do
	case "$f" in
		'h')
			usage
			exit
			;;

		'V')
			VOLUME="$OPTARG"

			# Quickly check if we have enough permission to launch btrfs commands
			if ! btrfs device stats "$VOLUME" >/dev/null 2>&1 ; then
				echo "UNKNOWN: unable to launch 'btrfs device stats $VOLUME' command (permissions ?)."
				exit $STATE_UNKNOWN
			fi

			# For information, add the number of devices to the perfdata
			NB_DEVICES="$(( $NB_DEVICES + $( btrfs fi show --raw "$VOLUME" | sed -n 's/^[[:space:]]*Total devices \([0-9]\+\) .*/\1/p' ) ))"

			# Check the device stats
			# (the kinda weird <<EOF at the end is to avoid entering a sub-shell, so we can access
			# our precious vars' content outside of the loop, even with prosix-strict dash)
			while read ITEM VALUE; do
				# Add the value to the perfdata
				OUTPUT_PERFDATA="$( printf "%s\n'%s'=%d;%d;%d;0;" "$OUTPUT_PERFDATA" "$ITEM" "$VALUE" "$WARNING_STATS" "$CRITICAL_STATS" )"

				# Check if the value is within ok/warn/critical ranges
				if [ "$VALUE" -gt "$CRITICAL_STATS" ]; then
					OUTPUT_EXIT_STATUS=$STATE_CRITICAL
					OUTPUT_DETAIL_CRITICAL="$OUTPUT_DETAIL_CRITICAL $ITEM:$VALUE"
				elif [ "$VALUE" -gt "$WARNING_STATS" ] && [ "$OUTPUT_EXIT_STATUS" != "$STATE_CRITICAL" ]; then
					OUTPUT_EXIT_STATUS=$STATE_WARNING
					OUTPUT_DETAIL_WARNING="$OUTPUT_DETAIL_WARNING $ITEM:$VALUE"
				fi

			done <<EOF
$( btrfs device stats "$VOLUME" )
EOF
			;;

		\?)
			usage
			exit 1
			;;
	esac
done

# Insert nb devices data into output
OUTPUT_PERFDATA="$( printf "%s\n%s" "$OUTPUT_PERFDATA" "'nb_devices_total'=$NB_DEVICES;;;1;" )"
OUTPUT_DETAIL_OK="$OUTPUT_DETAIL_OK - $NB_DEVICES $( [ "$NB_DEVICES" -eq 1 ] && echo "device" || echo "devices" )"

case "$OUTPUT_EXIT_STATUS" in
	'0')
		printf "OK%s" "$OUTPUT_DETAIL_OK"
		;;
	'1')
		printf "WARNING%s" "$OUTPUT_DETAIL_WARNING"
		;;
	'2')
		printf "CRITICAL%s" "$OUTPUT_DETAIL_CRITICAL"
		;;
	*)
		printf "UNKNOWN"
		;;
esac

# We sort the perfdata because of a weird bug in some icinga/pnp4nagios interactions
printf "|%s\n" "$( printf "%s" "$OUTPUT_PERFDATA" | sort | grep -v "^$" | tr "\n" " " )"
exit $OUTPUT_EXIT_STATUS