check_btrfs_stats

#!/bin/bash
# SvenVD 2015
# Note this plugin has only been tested on CentOS 7
# Note2 clear stats with btrfs device stats -z
# Make sure your nagios user can run  sudo btrfs device stats /*


while read line; do
        BTRFS=$(echo "$line" | cut -d" " -f3;)
        while read line; do
                STAT=$(echo $line | cut -d" " -f1)
                VALUE=$(echo $line | cut -d" " -f2)
                if [ "$VALUE" -eq 0 ];then
                        EXITCODES="$EXITCODES 0"
                        PERFDATA="$PERFDATA""$STAT=$VALUE "
                else
                        MSGNAGIOS="$MSGNAGIOS""$STAT has $VALUE for $BTRFS:: "
                        EXITCODES="$EXITCODES 2"
                        PERFDATA="$PERFDATA""$STAT=$VALUE "
                fi
        done< <(sudo /usr/sbin/btrfs device stats "$BTRFS")

done < <(mount -t btrfs)

####Substitute all : and . from PERFDATA output
        PERFDATA=$(echo "$PERFDATA" | sed 's/\[\///g' | sed 's/[]:./]/_/g')

####Generate nagiosoutput
if echo "$EXITCODES" | grep -q 2;then
        echo "CRITICAL: $MSGNAGIOS|$PERFDATA"
        exit 2;
elif echo "$EXITCODES" | grep -q 1;then
        echo "WARNING: $MSGNAGIOS|$PERFDATA"
        exit 1;
elif echo "$EXITCODES" | grep -q 3;then
        echo "UNKNOWN: $MSGNAGIOS|$PERFDATA"
        exit 3;
else
        echo "OK: $MSGNAGIOS|$PERFDATA"
        exit 0
fi