Custom SNMP based memory utilization bash script for

Project Description

Custom SNMP based memory utilization bash script for Nagios

We identified a need to monitor memory on a remote server with nagios and were unable to find a existing perl script to fit the requirement.  Prior to the week i didn't have much in the way of experience with SNMP or bash scripting.  3 days into the project to solve the problem i have a working solution based on google searches and self education that is effectively reporting memory totals, usage, free, percentage used, and performing logic on the used percentage to create ok|warn|critical states in nagios for reporting purposes.

for impact, i'm sharing the script.  I hope it helps you!




################################################################################
#
#Check Memory by SNMP of remote host
#By Dan Eakin - Last edit 3/1/2018
#
#This script is to acquire and math via SNMP the memory usage of a specific
#index. Based on passed variables it'll return context and state to nagios
#for use in monitoring memory on a specific server.
################################################################################

###
#Passed variables:
#$1 = host ip
#$2 = index of memory
#$3 = warn - if usage is above this value pass a warning state
#$4 = crit - if usage is above this value pass a critical state
###

#Get total
STORAGE=$(snmpget -Le -t 10 -r 5 -m ALL -v 2c -c YOURCOMMUNITYSTRINGHERE $1:161 HOST-RESOURCES-MIB::hrStorageSize.$2 | cut -d' ' -f4)

#get units
UNITS=$(snmpget -Le -t 10 -r 5 -m ALL -v 2c -c YOURCOMMUNITYSTRINGHERE $1:161 HOST-RESOURCES-MIB::hrStorageAllocationUnits.$2 | cut -d' ' -f4)

#TOTAL CALC
TOTALGB=$(bc <<< "scale=2;(($STORAGE * $UNITS / 1024 ^ 3))")

#GET USED
USED=$(snmpget -Le -t 10 -r 5 -m ALL -v 2c -c YOURCOMMUNITYSTRINGHERE $1:161 HOST-RESOURCES-MIB::hrStorageUsed.$2 | cut -d' ' -f4)

#USED CALC
USEDGB=$(bc <<< "scale=2;(($USED * $UNITS / 1024 ^ 3))")

#FREE CALC
FREE=$(bc <<< "scale=2;(($TOTALGB - $USEDGB))")

#math differences in percentages
PERCENTAGEUSED=$(bc <<< "scale=2;($USEDGB * 100 / $TOTALGB)")

#THRESHOLDS
if (( $(echo "$PERCENTAGEUSED $4" | awk '{print ($1 > $2)}') ));then
echo "CRITICAL- T: $TOTALGB U: $USEDGB F: $FREE P: $PERCENTAGEUSED"
exit 2
elif (( $(echo "$PERCENTAGEUSED $3" | awk '{print ($1 > $2)}') ));then
echo "WARNING- T: $TOTALGB U: $USEDGB F: $FREE P: $PERCENTAGEUSED"
exit 1
else
echo "OK- T: $TOTALGB U: $USEDGB F: $FREE P: $PERCENTAGEUSED"
exit 0
fi

Lessons Learned

Pretty happy with the process entirely so I'm going to say there's not much required.

Highlights

ahead of schedule
support from colleagues

Difficulties

steep learning curve

Technologies Used

Technical Skills Used

  • bash scripting
  • snmp
  • Lansing42.7325-84.5555
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