added script for ddns update for ufw access

debian/ddns-updater-for-ufw-access

@@ -0,0 +1,33 @@
+#!/bin/bash
+# Bash script to query DDNS service for hostname current IP address and create or update UFW firewall rules
+# to allow access to all ports and protocols from the dynamic IP address.
+# This script is intended to be run from a cron job with root privileges.
+# The script will only update the firewall rules if the IP address has changed.
+
+# Set the DDNS service URL
+DDNS_HOSTNAME="akanealw.com"
+# Get the DDNS hostname IP address
+DDNS_IP=$(dig +short ${DDNS_HOSTNAME})
+# Get the current IP allowed in UFW for this hostname
+OLD_IP=$(/usr/sbin/ufw status | grep $DDNS_HOSTNAME | head -n1 | tr -s ' ' | cut -f3 -d ' ')
+
+# Check if the DDNS hostname IP address is valid
+if [[ "${DDNS_IP}" =~ ^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
+  # Check if the old IP is valid
+  if [[ "${OLD_IP}" =~ ^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
+    # Check if the DDNS service IP address is different from the old IP address
+    if [[ "${DDNS_IP}" != "${OLD_IP}" ]]; then
+        # Delete the old rule
+        /usr/sbin/ufw delete allow from $OLD_IP to any
+        # Create a new rule for the new IP address
+        /usr/sbin/ufw allow from "${DDNS_IP}" to any comment $DDNS_HOSTNAME
+    else
+      echo "$0: The IP address is the same, no need to update the firewall rules."
+    fi
+  else
+    # Create a new rule for the new IP address
+    /usr/sbin/ufw allow from "${DDNS_IP}" to any comment $DDNS_HOSTNAME
+  fi
+else
+  echo "$0: DDNS IP address is not valid for ${DDNS_HOSTNAME}: ${DDNS_IP}"
+fi