flake-utils-plus VS napalm

You don't need channels to use nix-shell or nix-env. You can generate the Nix path and registry from your flake inputs. flake-utils-plus makes this easy with nix.generateRegistryFromInputs and nix.generateNixPathFromInputs.

Use flake-utils-plus to easily define multiple systems in flake.nix.and then use the --target-host flag of nixos-rebuild to deploy it remotely.

If you're trying to handle multiple systems with one config a flake is a significantly better option. I would personally recommend looking at flake-utils-plus and specifically this example config.

I looked at some past threads / examples and saw people recommend flake-utils-plus, but after reading the examples I don't understand how I would get home-manager on Darwin or Ubuntu.

Depending on your specific needs, the channelsConfig (modify arguments passed to Nixpkgs) and overlay tooling in flake-utils-plus may be adequate: https://github.com/gytis-ivaskevicius/flake-utils-plus/tree/...

For flakes you don't have to set up everything manually there are helper libraries, I use flake-utils-plus.

Converting to flakes is not that hard if you use a good library. The documentation is other people's configs, really.

Neat! I've been using flake-utils-plus's implementation until now. https://github.com/gytis-ivaskevicius/flake-utils-plus/blob/master/lib/repl.nix

I use flake-utils-plus based configuration to apply patches on top of nixpkgs where overlays don't suffice.

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.