I've been wanting to add a comment section to the site but I don't want to use any third-party services, so I hadn't done so until after finding out about Comentario, which is an open-source comment server that I'm now self-hosting an instance of. This would have been pretty simple to set up if I were using Debian/Ubuntu (for which Comentario has already been packaged) or if I were willing to use Docker, but my server's running NixOS, which didn't have a Comentario package.

Until now! I made one myself.

This ended up being much more complicated than I initially aassumed because, while building the backend was pretty easy, the frontend is built with Yarn, which isn't supported very well by the build tools available in Nixpkgs. I ended up having to go through a lot of trial-and-error to figure out exactly what build tools the frontend depended on -- for example, Hugo is used, but the docs, as of 2024-10-17, don't mention it.

I initially used mkYarnPackage, because that seemed like the obvious answer, but apparently that's not very useful for building web frontends, so I wasted a lot of time trying to get that to work until I just gave up and wrote a custom build script.

The main issue ended up being the yarn run generate step, which uses OpenAPI Generator, which nixpkgs does provide but which tries to download a specific version of itself at runtime, so I had write a script to patch the build config to use the nixpkgs version.

Its NixOS module is pretty standard for this sort of thing (just a simple systemd service and a Nginx vhost), and adding the web components to the site template was trivial, so at least everything else was easy.