#!/bin/bash
# Author Stefan Nonchev
# Nagios script for checking the number of existing snapshots and how old are these.
# The script should work with any ESXi 5.x
# Installation notes:
# On your nagios server execute:
#
# #sudo nagios
# #ssh-keygen
# copy the public certificate into /etc/ssh/keys-root/authorized_keys on each ESXi host that will be monitored

print_usage() {
        echo ""
        echo "Usage: $0 [esxi_hostname] [warn] [crit] [snapage]"
        echo "where [warn] and [crit] are the allowed numbers of snapshots and [snapage] is how old a snapshot is allowed to be"
        echo ""
        exit 3
}

case "$1" in
        --help)
                print_usage
                ;;
        -h)
                print_usage
                ;;
esac

if [ "$#" -ne "4" ]; then
        print_usage
fi

function date2stamp () {
    date --utc --date "$1" +%s
}

function dateDiff () {
    sec=86400
    dte1=$(date2stamp $1)
    dte2=$(date2stamp $2)
    diffSec=$((dte2-dte1))
    if ((diffSec < 0)); then abs=-1; else abs=1; fi
    echo $((diffSec/sec*abs))
}

i=0
total=0
dateNow=(`date '+%Y-%m-%d'`);
IFS="
"

# Getting VM IDs and names with vim-cmd
vmstr=''
vms=(`ssh root@$1 vim-cmd vmsvc/getallvms | sed -e '1d' -e 's/ \[.*$//' | awk '$1 ~ /^[0-9]+$/ {print  $1":"substr($0,8,80)}'`);
for vm in "${vms[@]}"; do
    id=`echo $vm | awk -F: '{print $1}'`
    #reformatting the sting
    vmname=`echo $vm | awk -F: '{print $2}' | sed 's/ *$//'`
    result=`ssh root@$1 vim-cmd vmsvc/snapshot.get $id | grep "Snapshot Name" | wc -l`
    if [ $result -ge 1 ]; then
        # we are getting only the oldest snapshot
        dateCreated=`ssh root@$1 vim-cmd vmsvc/snapshot.get $id | grep "Created On" | awk '{print $5}' | awk -F/ '{print $3"-"$1"-"$2}' | head -1`
        dateSnap=$(dateDiff $dateCreated $dateNow)
        if [ $dateSnap -le $3 ] ; then
            dateStatus=0
        elif [ $dateSnap -gt $3 ] ; then
            dateStatus=1
        fi
        vmstr=$vmstr$vmname"-"$dateSnap" days,"
        vmnames=$vmnames$vmname","
        let "total=$total+$result";
        let i++;
    fi
done

if [ ${#vmstr} -gt 0 ] ; then
    vmstr="${vmstr%?}"
fi
if [ ${#vmnames} -gt 0 ] ; then
    vmnames="${vmnames%?}"
fi

#IFS=""
if [ $total -eq 0 ] ; then
    echo "OK - $total snapshots found"
    exit 0
fi
if [ $total -le $2 ] ; then
    if [ $dateStatus -eq 0 ] ; then
           echo "WARNING - $total snapshots, oldest is below 3 days, VMs: $vmnames"
           exit 1
    elif [ $dateStatus -eq 1 ] ; then
           echo "CRITICAL - very old snapshots on: $vmstr"
           exit 2
    fi
fi

if [ $total -gt $2 ] ; then
    echo "CRITICAL - $total snapshots found on $vmnames"
    exit 2
fi