I have found Nix and NixOS to be able to absorb any amount of complexity I throw at it with grace.
If a Docker image truly is the best way to use a bit of functionality (like Home Assistant), then I will just configure NixOS to run it in podman as a systemd service with host networking.
I have not come across something that I could not package. The trick is that Nix composes functionality in a way that Dockerfiles or docker-compose configs cannot, because it's one language, one system, one abstraction.
If a Docker image truly is the best way to use a bit of functionality (like Home Assistant), then I will just configure NixOS to run it in podman as a systemd service with host networking.
I have not come across something that I could not package. The trick is that Nix composes functionality in a way that Dockerfiles or docker-compose configs cannot, because it's one language, one system, one abstraction.