How does this differ from the tooling that lets you build containers from nix?
https://github.com/pdtpartners/nix-snapshotter
so kind of allowing pull images from nix store, mounting shared host nix store per node into each container, incremental fast rebuilds, generating basic pod configs are good things.
and local, ci and remote runs same flows and envs.
I'm curious! and ignorant! help!
Is that via (centrally?) cached eval? or what? there's only so much room for magic in this arena.
When you create a Flox environment, we evaluate the Nix expressions once and store the concrete result (ie exact store paths) in FloxHub. The k8s node just fetches that pre-rendered manifest and bind-mounts the packages with no evaluation step at pod startup.
It's like the difference between giving the node a recipe to interpret vs. giving it a shopping list of exact items. Faster, safer, and the node doesn't need to know how to cook (evaluate Nix). I don't know, there's a metaphor here somewhere, I'll find it.
Only so much room for magic, for sure, but tons of room for efficiency and optimization.
Our catalog continuously pre-evaluates nixpkgs in the background. 'flox install' just selects from pre-evaluated packages -- no eval needed, ever. The k8s node fetches the manifest and mounts the packages.
Eval is done once, centrally, continuously. So... even more pre-val'd, so to speak.