#!/bin/sh

#-
# Copyright (c) 2017 Philip Paeps
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
#

#
# Nagios monitoring plugin for Tarsnap.  Checks if the latest archive is
# sufficiently fresh and returns archive statistics as performance data.
#

tmpfile=`mktemp /tmp/check-tarsnap.XXXXXX` || exit 3
cleanup() {
    rm -f ${tmpfile}
}
trap cleanup EXIT

# Sensible defaults
warn=86400    # one day
crit=259200   # three days
keyfile="$HOME/tarsnap-nagios.key"

cflag=
wflag=
xflag=
while getopts c:w:k:x: flag
do
    case $flag in
    c)  cflag=1
        cval="$OPTARG";;
    w)  wflag=1
        wval="$OPTARG";;
    k)  keyfile="$OPTARG";;
    x)  extra="$OPTARG";;
    ?)  printf "Usage: %s: [-k keyfile] [-c critical] [-w warning]\n" $0
        printf "           [-x extra_arguments_to_tarsnap]\n"
       exit 3;;
    esac
done
if [ ! -z "$cflag" ]; then
    case "$cval" in
    (*[!0-9]*|'')
        printf "Invalid arg for -c option: must be a positive integer\n"
	exit 3;;
    (*) crit=$cval;;
    esac
fi
if [ ! -z "$wflag" ]; then
    case "$wval" in
    (*[!0-9]*|'')
        printf "Invalid arg for -w option: must be a positive integer\n"
	exit 3;;
    (*) warn=$wval;;
    esac
fi

tarsnap="tarsnap --keyfile ${keyfile} ${extra}"

begin=$( date +%s )

${tarsnap} --list-archives -v >${tmpfile} 2>&1
if [ $? -ne 0 ]; then
    printf "UNKNOWN Couldn't list Tarsnap archives\n"
    cat ${tmpfile}
    exit 3
fi
last=$( cat ${tmpfile} | cut -f 2 | sort -u | tail -n 1 )

${tarsnap} --print-stats >${tmpfile} 2>&1
if [ $? -ne 0 ]; then
    # XXX Do we care if statistics fail?
    stats="-1 -1 -1 -1"
else
    stats=$( cat ${tmpfile} | grep -o '[[:digit:]]\+' )
fi

runtime=$(( $(date +%s) - begin ))

_printstats() {
    printf "All_archives_total_size=%dB;;;0; " $1
    printf "All_archives_compressed_size=%dB;;;0; " $2
    printf "Unique_data_total_size=%dB;;;0; " $3
    printf "Unique_data_compressed_size=%dB;;;0; " $4
    printf "Check_time=%ds\n" $5
}

when=$( date -j -f "%F %T" "${last}" +%s )
if [ ${when} -le $(( ${begin}-${crit} )) ]; then
    printf "CRITICAL last archive was made %s|" "${last}"
    rc=2
elif [ ${when} -le $(( ${begin}-${warn} )) ]; then
    printf "WARNING last archive was made %s)|" "${last}"
    rc=1
else
    printf "OK last archive was made %s)|" "${last}"
    rc=0
fi
_printstats ${stats} ${runtime}

exit $rc