Automatically update VPN gateway IP

vpn_ip_update.sh

#!/bin/bash

vpn_host="netherlands-udp.ivacy.net"
log_file="/var/log/vpn_ip_update.log"

log() {
  echo ${1} | tee ${log_file}
}

new_ip=$(host ${vpn_host} | awk '/has address/ { print $4 }')

current_rule=$(ufw status numbered | awk '/53\/udp/ { print $2 }' | cut -c 1)
current_ip=$(ufw status numbered | awk '/53\/udp/ { print $3 }')

log "VPN: ${vpn_host} has address ${new_ip}"
log "UFW: ${vpn_host} has address ${current_ip}"

if [ ${current_ip} == ${new_ip} ]; then
  log "IPs match, no restart necessary" 
else
  log "Updating last IP with current" 
  ufw --force delete ${current_rule}
  ufw allow out to ${new_ip} port 53 proto udp
fi