Google Domains Dynamic DNS Update Script

google-domains-dyndns-update.sh

#!/bin/bash

### Google Domains provides an API to update a DNS "Syntheitc record". This script
### updates a record with the script-runner's public IP, as resolved using a DNS
### lookup.
###
### Google Dynamic DNS: https://support.google.com/domains/answer/6147083
### Synthetic Records: https://support.google.com/domains/answer/6069273

HOSTNAME="yoursubdomain.domain.tld"
USERNAME="yourdyndnsuser"
PASSWORD="yourdyndnspassword"

IP=$(curl -s "https://domains.google.com/checkip")
URL="https://domains.google.com/nic/update?hostname=${HOSTNAME}&myip=${IP}"
curl --user ${USERNAME}:${PASSWORD} -s $URL