napalm VS NixOS-docker

I created https://github.com/nmattia/napalm/issues/34 and https://github.com/nmattia/naersk/issues/183 to move them to nix-community

Sure. NPM is the easy case because the package-lock.json file can easily be read by Nix and contains hashes for all of the packages. This means that simply be importing the file into Nix you can have a reproducible build. No Nix-specific maintenance required.

In the linked case I use this library to manage that https://github.com/nmattia/napalm (in that example I use master but for production I would pin a version). It simply parses the package-lock.json, downloads the packages and uses npm to build the node_modules folder. It also provides some convenient functions for building packages with "bin" files or just linking node_modules inside a build.

Note that this is more for project development. It doesn't use the "system" packages (intentionally) for Node, it fetches whatever versions you have specified from NPM. Nix will only provide the "native" stuff like Node and NPM themselves and any native libraries.

Luckily, I did not have to start from scratch as Nix serves their own docker image. I mounted one of my directories and was able to drop into a Nix shell with my configuration file.

There is one: https://github.com/NixOS/docker

But it's more of a Nix docker image than a NixOS one, because half of the things that NixOS gives you don't really make much sense in a docker image (systemd in a container?).

I only know of the nix package manager. https://hub.docker.com/r/nixos/nix

Ability to run buildkite agents inside a kubernetes cluster on preemble instances without need to modify agent’s Dockerfile every time new dependency comes up - was one of major reasons to learn Nix. I’m just using nixos/docker image as a base, install buildkite-agent and some base stuff like bash via nix-env inside Dickerfile, everything else lays in flake.nix of every project my dockerized nixified buildkite agent run.