DynDRest

Dynamic DNS Rest service

Give it a try!

DynDRest is a simple REST-service for dynamic DNS and is a more general variant of DDAuto. The basic idea is to have multiple implementations for different dns providers. AutoDNS will be one of them.

The restful-api can be used with many routers, for example the AVM Fritz!Box. DynDRest can be executed by commandline, init.d or systemd.

If you find a bug or certain features are missing, don't hesitate to file an issue on Github.

DynDRest is kindly supported by

Disclaimer

I'm not responsible for any data loss, hardware damage or broken keyboards. This guide comes without any warranty!

Big picture

DynDRest is running as a service. A client can access the service via url and basic-auth. Let's assume DynDRest is running on localhost, then we can update the IPv4 and IPv6 address of the host mydyndns.domain.com by calling the following curl command:

curl -u dyndns:test123 -i \ 
   "http://localhost:8081/update/mydyndns.domain.com/?apitoken=1234567890abcdf&ipv4=127.1.2.4&ipv6=2a03:4000:41:32::2"

For each host an api-token must be defined. If the api-token doesn't match the host, the update will be failed. Due to this security feature, DynDRest can be used by different people. They can't update the IPs each other.

Configuration and start

DynDRest is a spring boot application, that's why the application is extremely customizable just by configuration! Details of the configuration can be found here: https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#application-properties and https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#actuator.monitoring.customizing-management-server-port

Side note: To avoid the use of the java keystore tool, DynDRest could be run behind a proxy. Corresponding headers are set by default.

Here is the suggested directory/file structure:

├── /opt/dyndrest
│   ├── dyndrest.yml
│   ├── dyndrest-0.1.0.jar
│   ├── dyndrest.jar -> dyndrest-0.1.0.jar
│   ├── dyndrest-update.log   (log of the updates)
│   ├── logback.xml         (logback configuration for application and update logoging, optional)
│   ├── logback-update.xml  (extra logback configuration for update logging, optional include) 

Side note: If the names of the configuration files are kept as above, they will be found and loaded automatically.

dyndrest.yml defines the individual properties and will be merged with the default properties in the classpath, therefore the file can be kept as small as possible. A minimal configuration example can be found further below. If the file is inside the working directory, it is loaded automatically. The complete configuration setings can be found here.
Important: The basic-auth, the api-tokens and the credentials for AutoDNS should be defined in this file!
The configuration of Logback can be split into two files, one for the application logging and one for a the well-formatted zone update log. The second one is the one on which the log view is based.
For further information have look at Logback Configuration wiki article.

The start by command line looks like:

java -jar /opt/dyndrest/dyndrest.jar

DynDRest can also be started easily as a service. For further information, see https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#deployment.installing.nix-services

BTW: This project uses spring-doc to document the routes. The endpoints for this and the swagger-ui are disabled by default.

Configuration

This is a minimal configuration example for your individual properties file dyndrest.yml using the provider domainrobot:

spring:
  security:
    user:
      name: dyndns
      password: test123
      
dyndrest:
  provider: domainrobot

domainrobot:
  autodns:
    password: pwd_t
    user: user_t
  zones:
    - name: dynhost.info
      ns: ns.domain.info
      hosts:
        - myhost:1234567890abcdef

The 'zone' section defines a host myhost.dynhost.info with the api-token 1234567890abcdef.

Routes

All routes are secured by basic-auth. A detailed description of the routes can be found at the OAS3 documentation.

There are two additional routes which deliver web pages:

• [/]: A simple greeting page which is enabled by default. It can be disabled by setting the property dyndrest.greeting-enabled=false.
• [/log]: Delivers a simple web page to view the zone update logs and is secured by basic-auth and can be configured by setting the two properties dyndrest.update-log-user-name and dyndrest.update-log-user-password. It is enabled by default but it can be disabled by setting the property dyndrest.update-log-page-enabled=false.

Suggested AutoDNS setup

For security reasons, it makes sense to create a separate owner for the zone updated by DynDRest. This owner just needs the permission for zone-info and zone-updates!

Setup a router for dynamic DNS

As an example, let's have a look at the setup of dynamic DNS in the Fritz!Box 7590. The following settngs are required:

• DynDNS Provider: User-defined
• Domain name: The hostname for which the IPs should be updated.
• Username / Password: The credentials for basic-auth.
• Update-URL: {baseUrl}/update/<domain>/?apitoken=[yourApitoken]&ipv4=<ipaddr>&ipv6=<ip6addr>
  If both IP parameters are omitted, an attempt is made to fetch the remote IP.