#!/bin/bash

TUNE2FS="/sbin/tune2fs"

MOUNT_MAX=14
INTERVAL_MAX=200
MAIL_ALERT="alert3@evolix.fr"

PROGNAME=`/usr/bin/basename $0`

# Nagios compatibility
STATE_OK=0
STATE_WARNING=1
STATE_CRITICAL=2
STATE_UNKNOWN=3
STATE_DEPENDENT=4

print_usage() {
    echo "Usage: $PROGNAME --dev /dev/sdaX [--mount-max $MOUNT_MAX] [--interval-max $INTERVAL_MAX] [--alert]"
    echo "Usage: $PROGNAME -d /dev/sdaX [-c $MOUNT_MAX] [-i $INTERVAL_MAX] [-a]"
    echo "Usage: $PROGNAME --help"
}

print_help() {
    print_usage
    echo ""
    echo "Options:"
    echo "--dev, -d /dev/sdNX"
    echo "--mount-max, -c X"
    echo "--interval-max, -i X (days)"
    echo "--alert, -a (send a mail to $MAIL_ALERT if state critical)"
}

alert_mail() {
# $1 max_mount
# $2 days

    if [ "$send_mail" = "1" ]; then
        if [ "$exitstatus" = "$STATE_CRITICAL" ]; then
            echo "From: Equipe Evolix <equipe@evolix.fr>
To: $MAIL_ALERT
Subject: [alert] Fsck on $(hostname)

Number of mount since last fsck: $1
Days since last fsck: $2

"|/usr/lib/sendmail -oi -t -f "$MAIL_ALERT"
        fi
    fi
}

send_mail=0
exitstatus=$STATE_OK

# check command line arguments

if [ $# -lt 1 ]; then
    print_usage
    exit $STATE_UNKNOWN
fi

while test -n "$1"; do
    case "$1" in
        --help)
            print_help
            exit $STATE_OK
            ;;
        -h)
            print_help
            exit $STATE_OK
            ;;
        --dev)
            dev=$2
            shift
            ;;
        -d)
            dev=$2
            shift
            ;;
        --mount-max)
            mount_max=$2
            shift
            ;;
        -c)
            mount_max=$2
            shift
            ;;
        --interval-max)
            interval_max=$2
            shift
            ;;
        -i)    
            interval_max=$2
            shift
            ;;
        --alert)
            send_mail=1
            ;;
        -a)
            send_mail=1
            ;;
        *)
            echo "Unknown argument: $1"
            print_usage
            exit $STATE_UNKNOWN
            ;;
    esac
    shift
done

[ -z "$dev" ] && print_usage && exit $STATE_UNKNOWN
[ -z "$mount_max" ] && mount_max=$MOUNT_MAX
[ -z "$interval_max" ] && interval_max=$INTERVAL_MAX

# is $dev support tune2fs ?
bad_magic=$($TUNE2FS -l $dev|grep "Bad magic number")
[ -n "$bad_magic" ] && echo "Bad magic number in super-block while trying to open $dev" && exit $STATE_UNKNOWN

# grep max_count && last_checked
max_count=$($TUNE2FS -l $dev|grep "Mount count" | awk -F":" '{ print $2 }'| sed 's/^\s*//')
last_checked=$($TUNE2FS -l $dev|grep "Last checked"| awk -F":" '{ print $2":"$3":"$4 }'|sed 's/^\s*//')

[ -z "$max_count" ] && echo "No Mount count value on $TUNE2FS $dev" && exit $STATE_UNKNOWN
[ -z "$last_checked" ] && echo "No Last checked value on $TUNE2FS $dev" && exit $STATE_UNKNOWN

# check max mount
if [ $max_count -ge $mount_max ]; then
    echo "Number of mount since last fsck: $max_count"
    echo " - threshold $mount_max reached !\n"
    exitstatus=$STATE_CRITICAL;
fi

# compute day interval
timestamp=$( date -d "$last_checked" "+%s" )
today=$( date "+%s" )
days=$(( ($today - $timestamp) / 86400 ))

if [ $days -ge $interval_max ]; then
    echo "Days since last fsck: $days"
    echo " - threshold $interval_max reached !\n"
    exitstatus=$STATE_CRITICAL;
fi

alert_mail $max_count $days

exit $exitstatus