This script updates the DNS record for a specified domain using INWX's DynDNS service. It checks the current public IP address and updates the DNS record if the IP has changed. The script uses environment variables for sensitive information and logs all actions.

inwx-dyndns.sh

#!/bin/bash

# Configuration variables
DOMAIN="${INWX_DOMAIN}"
SUBDOMAIN="home"
INWX_USER="${INWX_USERNAME}"
INWX_PASS="${INWX_PASSWORD}"
LOG_FILE="/home/pi/inwx-dyndns_update.log"

# Get current public IP address
CURRENT_IP=$(curl -s https://api.ipify.org)

# Read last known IP address from log file
LAST_IP=$(tail -n 1 "$LOG_FILE" | awk '{print $NF}')

# Check if IP has changed
if [ "$CURRENT_IP" != "$LAST_IP" ]; then
    echo "IP has changed. Updating DNS..."

    # Call INWX API to update DNS record
    UPDATE_RESULT=$(curl -s -u "$INWX_USER:$INWX_PASS" \
        "https://dyndns.inwx.com/nic/update?hostname=$SUBDOMAIN.$DOMAIN&myip=$CURRENT_IP")

    # Log the result
    echo "$(date '+%Y-%m-%d %H:%M:%S') - IP updated: $CURRENT_IP - Result: $UPDATE_RESULT" >> "$LOG_FILE"
else
    echo "IP has not changed. No update necessary."
fi