Watch server load and notify via ntfy.sh when load is low

watch-load.sh

#!/bin/bash
# ./watch-load.sh — run this on the server, it will notify you when load drops
# ./watch-load.sh <threshold>, e.g. ./watch-load.sh 1.2 to set threshold to 1.2. Default to 2.0
NTFY_TOPIC="<INSERT NTFY TOPIC>"
THRESHOLD="${1:-2.0}"    # first arg, default 2.0; e.g. ./watch_load.sh 1.5
CHECK_INTERVAL=60        # seconds between checks
SUSTAINED_CYCLES=3       # must be low for N consecutive checks before alerting
low_count=0
echo "Watching load average... threshold: <$THRESHOLD for ${SUSTAINED_CYCLES} consecutive checks"
while true; do
  LOAD=$(awk '{print $2}' /proc/loadavg)   # $2 = 5-min avg, $1 = 1-min, $3 = 15-min
  TIMESTAMP=$(date '+%Y-%m-%d %H:%M:%S')
  echo "[$TIMESTAMP] Load (5m): $LOAD"
  if (( $(echo "$LOAD < $THRESHOLD" | bc -l) )); then
    (( low_count++ ))
    echo "  → Low load detected ($low_count/$SUSTAINED_CYCLES)"
  else
    low_count=0   # reset if load spikes back up
  fi
  if (( low_count >= SUSTAINED_CYCLES )); then
    curl -s \
      -H "Title: Server Load is Low ✅" \
      -H "Priority: high" \
      -H "Tags: bell" \
      -d "5-min load: $LOAD (below $THRESHOLD for ${SUSTAINED_CYCLES} checks) | $TIMESTAMP" \
      ntfy.sh/$NTFY_TOPIC
    echo "Notification sent. Exiting."
    break
  fi
  sleep $CHECK_INTERVAL
done