ovh-dns-updater

simple python script to update A/AAAA DNS records at OVH registrar

This script can maintain the A and/or AAAA DNS records (*) of all your domains and subdomains hosted on the machine running this script, using OVH API. It is especially usefull it you are self-hosting and have only a semi-permanent IP address with your ISP.

(* The script handles IPV4 and/or IPV6 addressing, given what is available)

Why yet another script for doing that?

There are tons of solutions for updating DNS records out there, and even pretty good ones. For instance one could use this dns updater, or the dyndns client ddclient. So why coming up with my own?

Well, OVH's DynHost implementation that ddclient uses is crippled as it cannnot:

• do multiple domain/subdomains with a single id set (OVH's Dynhost requires separate logins per subdomain!).
• update AAAA records if you have ivp6 enabled (OVH's DynHost supports ipv4 only).

And all OVH-API scripts I could find were not filling the bill for me. They are either unsuited or too heavy, complex universal tools. For this task, I prefer a simple, easy to understand script that does little and that I can easily modify when needed.

If you have already created DynHost records in OVH, I believe the script would suppress them at the first update, but you can manually suppress them to be on the safe side. Alternatively, you can modify the script so that it updates dynhost records, if you prefer.

What this script does

The script queries the current public IP addresses (V4 and V6) and checks the DNS A/AAAA records at OVH for all domain/subdomains hosted on the machine (list defined as a dictionary in the script).

If needed, the record is updated or created (You can add a new subdomain this way).

If either IPV4 or IPV6 address is not available and if it is not indicated as required, then any corresponding DNS record is suppressed (Otherwise your site will be unreachable with this ip version). Such situation presumably arises because you disabled that ip version in your internet box (or your new ISP does not offer it).

Optionally, updating an IP addressing mode (4 or 6) can be disabled for any given domain/subdomain (for intance, if you want it accessible only in IPV4).

Setting up

this script needs extra modules: pip install ovh requests

In order to acccess the OVH API from this script, you need to generate API access keys at this site https://eu.api.ovh.com/createToken/
(or use another access point relevant for your OVH subscription)

Provide your OVH login and password, a script name, a purpose, a validity duration for the keys and ask for the four permissions:

GET /domain/zone/*
PUT /domain/zone/*
POST /domain/zone/*
DELETE /domain/zone/* (optionnal, since should rarely be useful)

This will allow the script to

• read the statuses of your domains/subdomains (GET)
• update records (PUT)
• create inexistent records and refresh (POST)
• delete record if the ipv6 or ipv4 address no longer exists

The keys delivered should be inserted in the script.

Other config parameters (domain names etc.) are also setup directly inside the script. See explanations in the code.

Run periodically with systemd

To run the updater automatically, copy (or link) the ovh-dns-updater.timer and ovh-dns-updater.service files in /etc/systemd/system and run systemctl enable ovh-dns-updater.timer systemctl start ovh-dns-updater.timer