nsupdate_for_fritz

nsupdate_for_fritz gets the current IPv4 address of your AVM FRITZ!Box and then uses BIND's nsupdate to update one or more A records with it. It can also do the same for IPv6 addresses (AAAA records) of hosts on your network.

Additionally, sending TXT records, i.e. for Let's Encrypt, is possible.

Install

Requirements

nsupdate_for_fritz requires Python 3.9 or later, the requests library (which will be auto-installed if you proceed as below) and nsupdate.

• Debian/Ubuntu: apt install dnsutils
• Red Hat/Fedora: dnf install bind-utils
• FreeBSD: pkg install bind-tools python3

Global or User install

cd to this directory and either

• pip install . for a global install or
  • Previously, you might want to create and activate a virtual environment (python -m venv venv, source venv/bin/activate).
• pip install --user . for a user-only install
  • Add ~/.local/bin to your PATH environment variable if you have never used this before

Via Docker

Run docker build . --tag nsupdate_for_fritz

Configure

Generate a Key

• tsig-keygen -a HMAC-SHA512 KEY_NAME_HERE

(Skip this step if you want to use some existing key.)

Create a Configuration File

Copy config.ini.example to config.ini, edit and replace all the all-caps placeholders with your nameserver, the zone name, the key from the step above etc.

Adjust the [hosts] and [txt] sections for your network, you can delete the latter section if you do not need to update any TXT records.

Configure Your Nameserver

If you are running your own nameserver, the configuration for it should be similar to this one (the key section is the output of tsig-keygen step above):

key "KEYNAME" {
        algorithm hmac-sha512;
        secret "SOME_SECRET_HERE";
};

zone "test.example.com" {
        type master;
        allow-update {
                key "KEYNAME";
        };
        allow-query { any; };
        file "/usr/local/etc/namedb/dynamic/test.example.com";
};

Run

Run nsupdate_for_fritz --dry-run config.ini to test your configuration, then run nsupdate_for_fritz config.ini and add it to your crontab or any other task runner.

If nsupdate_for_fritz cannot be found, either try fixing your PATH environment variable or running via python -m nsupdate_for_fritz instead.

Via Docker

docker run -i localhost/nsupdate_for_fritz --dry-run - < config.ini
docker run -i localhost/nsupdate_for_fritz - < config.ini