ddnsclient

This application can be use to update dynamic hostnames. Currently it implements only the ddnss.de provider, but it is extensible and more providers can be added easily.

This project uses Quarkus.

Configuration

ddnsclient requires a configuration in json format. It expects to find a file config.json in its working directory. The configuration can contain a list of update targets:

[
  {
    "provider": "<dyndns-provider>",
    "token": "<update-token>",
    "hostname": "<dynamic-hostname>"
  }
]

ddnssclient can also be configured using some properties or environment variables

Property	Environment variable	Value	Default
ddnsclient.interval	DDNSCLIENT_INTERVAL	e.g. "3600s", "60m", "1h"	"5m"
ddnsclient.ip-provider	DDNSCLIENT_IP_PROVIDER	an ip lookup provider (see below)	null
ddnsclient.backoff-duration	DDNSCLIENT_BACKOFF_DURATION	e.g. "60s", "1m"	"300s"

IP lookup

In order to update a hostname, ddnsclient needs to know about the current public ip addresses of the machine it runs on. For this, it uses one of the following ip lookup providers:

• ifconfig.me
• ipify.org
• ident.me
• nnev.de
• icanhazip.com

If no specific provider has been configured (see above), each request chooses a random provider from this list.