#!/usr/bin/env bash

# Nagios Exit Codes
OK=0
WARNING=1
CRITICAL=2
UNKNOWN=3

#   init exit code:
final_exit_code=$OK

usage()
{
cat <<EOF

Check the capacity of all ext3/ext4/xfs volumes from fstab using df.

     Options:
        -c         Critical threshold as an int (0-100)
        -w         Warning threshold as an int (0-100)

Usage: $0 -c 95 -w 90
EOF
}

if [ $# -lt 4 ];
then
	usage
	exit 1
fi

# Define now to prevent expected number errors
critlimit=0
warnlimit=0


while getopts "hc:w:" OPTION
do
     case $OPTION in
         h)
	         usage
             ;;
         c)
	         critlimit="$OPTARG"
             ;;
         w)
             warnlimit="$OPTARG"
             ;;
         \?)
             exit 1
             ;;
     esac
done

# get volumes from fstab file:
fstabvols=$( grep  -v  '^#' /etc/fstab | grep -E 'ext3|ext4|xfs' | sed 's/\t/ /g' | tr -s ' ' | cut -f2 -d' ' )

exitcode=0

for VOL in $fstabvols;do
    PCT=$(df -h "$VOL" | awk '!/Filesystem/ { print $5 }' | sed 's/%//')
    SIZE=$(df -h "$VOL" | awk '!/Filesystem/ { print $2 }')
    USED=$(df -h "$VOL" | awk '!/Filesystem/ { print $3 }')

    if [ $PCT -gt $critlimit ]; then
            echo "$VOL is at ${PCT}% capacity! $USED of $SIZE"
            # CRITICAL is the highest priority:
            final_exit_code=$CRITICAL
    elif [ $PCT -gt $warnlimit ]; then
            echo "$VOL is at ${PCT}% capacity! $USED of $SIZE"
            if [ $final_exit_code -ne $CRITICAL ] && [ $final_exit_code -ne $UNKNOWN ];then
              final_exit_code=$WARNING
            fi
    elif [ $PCT -le $warnlimit ]; then
            echo "$VOL is at ${PCT}% capacity, $USED of $SIZE"
            # OK is is the lowest priority:
            if [ $final_exit_code -ne $CRITICAL ] && [ $final_exit_code -ne $WARNING ] && [ $final_exit_code -ne $UNKNOWN ];then
              final_exit_code=$OK
            fi
    else
            echo "Can't read the space of $VOL, please check manually! "
            # UNKNOWN is the second highest priority:
            if [ $final_exit_code -ne $CRITICAL ];then
              final_exit_code=$UNKNOWN
            fi
    fi

done


exit $final_exit_code