Docker Hetzner DDNS

This small Alpine Linux based Docker image will allow you to use the free Hetzner DNS Console as a Dynamic DNS Provider (DDNS).

This is a multi-arch image and will run on amd64, aarch64, and armhf devices, including the Raspberry Pi.

Image Variants

Architecture	OS
x64	Alpine Linux
arm32v6	Alpine Linux
arm64	Alpine Linux

Usage

Quick Setup:

docker run \
  -e API_KEY=xxxxxxx \
  -e ZONE=example.com \
  -e SUBDOMAIN=subdomain \
  ghcr.io/ptpu/docker-hetzner-ddns

Parameters

• --restart=always - ensure the container restarts automatically after host reboot.
• -e API_KEY - Your Hetzner API token. See the Creating a Hetzner DNS Console API token below. Required
  • API_KEY_FILE - Path to load your Hetzner DNS Console API token from (e.g. a Docker secret). If both API_KEY_FILE and API_KEY are specified, API_KEY_FILE takes precedence.
• -e ZONE - The DNS zone that DDNS updates should be applied to. Required
  • ZONE_FILE - Path to load your Hetzner DNS Console Zone from (e.g. a Docker secret). If both ZONE_FILE and ZONE are specified, ZONE_FILE takes precedence.
• -e SUBDOMAIN - A subdomain of the ZONE to write DNS changes to. If this is not supplied the root zone will be used.
  • SUBDOMAIN_FILE - Path to load your Hetzner DNS Console Subdomain from (e.g. a Docker secret). If both SUBDOMAIN_FILE and SUBDOMAIN are specified, SUBDOMAIN_FILE takes precedence.

Optional Parameters

• -e TTL=86400 - Set to any Integer (in seconds) to change the Time-To-Live for the created record. Defaults to 86400.
• -e RRTYPE=A - Set to AAAA to use set IPv6 records instead of IPv4 records. Defaults to A for IPv4 records.
• -e DELETE_ON_STOP - Set to true to have the dns record deleted when the container is stopped. Defaults to false.
• -e INTERFACE=tun0 - Set to tun0 to have the IP pulled from a network interface named tun0. If this is not supplied the public IP will be used instead. Requires --network host run argument.
• -e CUSTOM_LOOKUP_CMD="echo '1.1.1.1'" - Set to any shell command to run them and have the IP pulled from the standard output. Leave unset to use default IP address detection methods.
• -e DNS_SERVER=10.0.0.2 - Set to the IP address of the DNS server you would like to use. Defaults to 1.1.1.1 otherwise.
• -e CRON="@daily" - Set your own custom CRON value before the exec portion. Defaults to every 5 minutes - */5 * * * *.

Creating a Hetzner DNS Console API token

To create a Hetzner DNS Console API token for your DNS zone go to https://dns.hetzner.com/settings/api-token and follow these steps:

1. Click Create access token
2. Provide the token a name, for example, hetzner-ddns
3. Complete the wizard and copy the generated token into the API_KEY variable for the container

Multiple Domains

If you need multiple records pointing to your public IP address you can create CNAME records in Hetzner DNS Console.

IPv6

If you're wanting to set IPv6 records set the environment variable RRTYPE=AAAA. You will also need to run docker with IPv6 support, or run the container with host networking enabled.

Docker Compose

If you prefer to use Docker Compose:

version: '3'
services:
  hetzner-ddns:
    image: ghcr.io/ptpu/docker-hetzner-ddns
    restart: always
    environment:
      - API_KEY=xxxxxxx
      - ZONE=example.com
      - SUBDOMAIN=subdomain

License

Copyright (C) 2017-2020 oznu
Copyright (C) 2022-2024 ptpu

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.