#!/bin/bash
#UPS settings
HOST="10.10.100.2"
COMMUNITY="public"
#minimal voltage sufficient for your UPS model to not switch to batteries
VOLTS_MIN=160
#minimal runtime you need to properly shutdown all VMs and Xen hosts
MINUTES_MIN=15
#administrator email (better if it's crossposted to sms in case shutdown is initiated)
EMAIL="admin@somedomain.tld"
SNMPGET=`which snmpget 2>/dev/null`
SNMPOPTS="-Ov -Oq -v1 -r10 -t2 -c ${COMMUNITY} ${HOST}"
#Input voltage OID
OID_VOLTS_IN=".1.3.6.1.4.1.318.1.1.1.3.2.1.0"
#Battery runtime remaining OID
OID_RUNTIME="1.3.6.1.4.1.318.1.1.1.2.2.3.0"
VALUE_VOLTS_IN=`${SNMPGET} ${SNMPOPTS} $OID_VOLTS_IN`
VALUE_RUNTIME=`${SNMPGET} ${SNMPOPTS} $OID_RUNTIME`
#SNMP runtime value reported as D:H:M:S.00
#let's convert it into minutes for convenience
OFS="$IFS"
IFS=":"
arr=( $VALUE_RUNTIME )
IFS="$OFS"
DAYS=${arr[0]}
HOURS=${arr[1]}
MINUTES=${arr[2]}
MINUTES_LEFT=$(($DAYS*24*60+$HOURS*60+$MINUTES))
if [ $VALUE_VOLTS_IN -lt $VOLTS_MIN ]
  then
    echo "Input voltage is too low ($VALUE_VOLTS_IN). $MINUTES_LEFT minutes of UPS runtime remaining." | mail -s "UPS: Power failure report" $EMAIL
fi
if [ $MINUTES_LEFT -lt $MINUTES_MIN ]
  then
    echo "Achtung! $MINUTES_LEFT minutes of UPS runtime remaining - shutdown initiated." | mail -s "UPS: Xenserver pool shutdown initiated." $EMAIL
    #let the message pass through:
    sleep 3
    #xe_shutdown_vms_and_hosts
fi