restart livekit when public ip changes, for DDNS setups

livekit-restart.sh

#!/usr/bin/env bash

POLL_INTERVAL=600   # seconds
LAST_IP=""

on_ip_change() {
  local old_ip="$1"
  local new_ip="$2"

  echo "$(date '+%Y-%m-%d %H:%M:%S') IP CHANGED: $old_ip -> $new_ip"
  docker restart livekit
}

while true; do
  TIMESTAMP=$(date '+%Y-%m-%d %H:%M:%S')

  CURRENT_IP=$(curl -s --max-time 5 ifconfig.io)

  if [[ -z "$CURRENT_IP" ]]; then
    echo "$TIMESTAMP request failed (empty response)"
  elif [[ ! "$CURRENT_IP" =~ ^[0-9a-fA-F:.]+$ ]]; then
    echo "$TIMESTAMP invalid response: $CURRENT_IP"
  else
    echo "$TIMESTAMP current IP: $CURRENT_IP"

    if [[ "$CURRENT_IP" != "$LAST_IP" ]]; then
      if [[ -n "$LAST_IP" ]]; then
        on_ip_change "$LAST_IP" "$CURRENT_IP"
      fi
      LAST_IP="$CURRENT_IP"
    fi
  fi

  sleep "$POLL_INTERVAL"
done