Marlin's firmware DDNS update for Google Domains

ddns-start.sh

#!/bin/sh
# (Copied from Marlin's examples)

# This script should be placed at /jffs/scripts/ddns-start
#     chmod a+x ddns-start
# Finally set to custom in WAN -> DDNS.
# more info: https://github.com/RMerl/asuswrt-merlin/wiki/Custom-DDNS#google-domains

# Get the following login info from Google Domains' dashboard
U=???
P=???
D=your.domain
H=subdomain

google_dns_update() {
  CMD=$(curl -s https://$1:[email protected]/nic/update?hostname=$4.$3)
  logger "google-ddns-updated: $CMD"
  case "$CMD" in
    good*|nochg*) /sbin/ddns_custom_updated 1 ;;
    abuse) /sbin/ddns_custom_updated 1 ;;
    *) /sbin/ddns_custom_updated 0 ;;
  esac
}

google_dns_update $U $P $D $H

exit 0