A bash client to update Dynamic DNS (such as duckdns)

update-duck.sh

#!/bin/bash

# Designed to be invoked every 5 minutes by cron
# See: https://www.duckdns.org/install.jsp

# crontab -e
# */5 * * * * /home/rpi/duckdns/update-duck.sh >/dev/null 2>&1

MYDOMAIN='your-sub-domain'
TOKEN='your-token'
LOGFILE='/home/rpi/duckdns/duck-history.log'

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

RESPONSE=$(curl -s "https://www.duckdns.org/update?domains=${MYDOMAIN}&token=${TOKEN}&ip=")
if [ "$RESPONSE" = "OK" ]; then
    echo "$TIMESTAMP - successful" >> "${LOGFILE}"
else
    echo "$TIMESTAMP - failed: $RESPONSE" >> "${LOGFILE}"
fi