Track Public IP for OPNsense

track_public_IP.sh

#!/bin/sh

TRACKING_FILE="/tmp/public_ip.log"

# Get Public IP adress
get_public_ip() {
    # dig @resolver4.opendns.com myip.opendns.com +short -4
    # OPNsense does not have dig
    drill @resolver4.opendns.com myip.opendns.com | grep "myip.opendns" | grep -v ";" | awk '{print $5}'
}

update_file() {
    timestamp=$(date +"%Y-%m-%d %T")
    # Log the IP address and timestamp to the file
    echo "$1 since $timestamp" >> $TRACKING_FILE
}

# Initialize the previous IP address
if [ -f "$TRACKING_FILE" ]; then
    prev_ip=$(tail -n 1 "$TRACKING_FILE" | awk '{print $1}')
else
    prev_ip=$(get_public_ip)
    # Initialize the file
    update_file "$prev_ip"
fi

# Get the current IP address
current_ip=$(get_public_ip)

# Check if the IP address has changed
if [ "$current_ip" != "$prev_ip" ]; then
    # Write new IP to file
    update_file "$current_ip"
fi