Awesome

NixOS-DNS

What do you get with NixOS-DNS:

• ✅ NixOS module
• ✅ Utility functions
• ✅ Zonefile generation
• ✅ Octodns config generation
• ✅ Auto generated docs
• ✅ Unit tests

Quick start

There is a usage example/template with comments in ./example, you can try it out locally by doing:

nix flake init -t github:Janik-Haag/nixos-dns

Docs

View the docs here Or view it locally:

nix build github:Janik-Haag/nixos-dns#docs && xdg-open result/index.html

Motivation

I started using octodns as dns deployment tool some time ago which works like a charm. But it bothered me that every time I wrote a new service config, I had to not just go and define the domain in the module but also in the octodns config. Which got particularly annoying because of context switches between nix and yaml. But not just that, it also prevented me from using nix's awesome versatility when it comes to dns, for example I have a prometheus-node-exporter.nix which gets imported by every server in my flake, and has a let binding at the top defining:

domain = "${config.networking.hostName}.prometheus.${config.networking.domain}";

which automatically generates a domain like myHost1.prometheus.example.com for every server that imports it. There is just a small problem: I now also have to add a entry for every host to my octodns config, which also makes the nixos module less portable. So I had the idea of writing a NixOS module that provides domain meta data per host and per module, to automagically generate dns entries from. Which ended up as networking.domains.baseDomains and networking.domains.subDomains. The idea is that you use baseDomains on a per host basis which will define the default value for every subDomain that matches a baseDomain, and then use subDomains in your modules.