Create and update DNS records for a host using IONOS' API for use as a DynDNS (for example via a cronjob). The script will create A and/or AAAA records if none already exists for the host and update existing ones to reflect the new public IP.

The public IP-Address is determined in two ways:

• IPv4: uses the ipify.org API
• IPv6: uses the ip address show command

By default the name of the A/AAAA record that will be created/updated is one that matches the output from the command hostname -f.
Update your /etc/hosts file with your FQDN if it's not already there.
Alternatively you can override this default value by using the -H or --fqdn parameter.

• Linux
• Python 3
• IONOS API key

You can create an API key here: https://developer.hosting.ionos.de/keys
The API is still in Beta and not enabled by default. In my case I had to call the customer support hotline and request to be enabled for the API.

This example shows how to update the AAAA record every 5 minutes and save the script output to a file:

1. Download the script and make sure it is executable

wget https://raw.githubusercontent.com/lazaroblanc/IONOS-DynDNS/main/ionos_dyndns.py
chmod +x ionos_dyndns.py

2. Open your crontab file with crontab -e
3. Paste this line:

*/5 * * * * ./ionos_dyndns.py --AAAA --api-prefix $publicprefix --api-secret $secret >> ionos_dyndns.log

usage: ionos_dyndns.py [-h] [-4] [-6] [-i] [-H] --api-prefix  --api-secret

Create and update DNS records for this host using IONOS' API to use as a sort of DynDNS (for example via a cronjob).

optional arguments:
  -h, --help         show this help message and exit
  -4, --A            Create/Update A record
  -6, --AAAA         Create/Update AAAA record
  -i , --interface   Interface name for determining the public IPv6 address (Default: eth0)
  -H , --fqdn        Host's FQDN (Default: hostname -f)
  --api-prefix       API key publicprefix
  --api-secret       API key secret

• improve log messages (add a timestamp)
• refactor duplicate code (~ line 94)