Google Cloud Platform (GCP) instance idle shutdown

gcloud-idle-shutdown.sh

#!/bin/bash

#This script will shut down an instance after 30mins of cpu idling below threshold.
#
# Add to instance metadata with `gcloud compute instances add-metadata \
#   instance-name --metadata-from-file startup-script=idle-shutdown.sh` and reboot
# NOTE: requires `bc`, eg, sudo apt-get install bc
#
# Modified from https://stackoverflow.com/questions/30556920/how-can-i-automatically-kill-idle-gce-instances-based-on-cpu-usage

threshold=0.4

count=0
while true
do

  load=$(uptime | sed -e 's/.*load average: //g' | awk '{ print $3 }')
  res=$(echo $load'<'$threshold | bc -l)
  if (( $res ))
  then
    echo "Idling.."
    ((count+=1))
  fi
  echo "Idle minutes count = $count"

  if (( count>30 ))
  then
    echo Shutting down
    # wait a little bit more before actually pulling the plug
    sleep 2
    sudo poweroff
  fi

  sleep 60

done