Disk monitor with slack notification

disk-monitor.sh

#!/bin/bash

MAX=90
WEBHOOK="https://slack-incomming-webhook-url"
PART="/dev/xvda1"
MACHINE_NAME="hostname"

USE=`df -h | grep $PART | awk '{ print $5 }' | cut -d'%' -f1`
if [ $USE -gt $MAX ]; then
  curl -X POST -H 'Content-type: application/json' \
    --data '{"text":"<!channel|channel> Machine *'$MACHINE_NAME'* is running out of disk space (usage: '$USE'%)"}' \
    $WEBHOOK
fi