nix-helpers VS nixos-generators

Yes, to get Nixpkgs it's much faster to use `fetchTarball`.

You're right that `builtins.fetchTarball` is faster than `builtins.fetchGit` (due to the ridiculous amount of commits in the Nixpkgs repo). I like to keep such definitions in a single, company-wide/project-agnostic git repo (what the Nix Pills series calls the "repository pattern"), and have individual projects import them via `builtins.fetchGit`.

Many years ago we didn't have `builtins.fetchGit`, so had to use the 'fetchgit' function from Nixpkgs instead. That created a chicken-and-egg situation if we wanted to take the Nixpkgs version from some other git repo; hence needing to "bootstrap" via `(import { config = {}; }).fetchgit`, and cross our fingers that `NIX_PATH` wasn't set to some crazy value (which, of course, I would inevitably do... https://github.com/Warbo/haskell-te/blob/24475a229908caa3447... )

Note that we need `config = {};` when importing Nixpkgs to avoid an impurity which tries to read files in $HOME. More recent versions of Nixpkgs also need `overlays = [];` to avoid another impurity (looks like this changed at Nixpkgs 17.03, according to https://github.com/Warbo/nix-helpers/blob/master/nixpkgs.nix )

Where nixpkgs2105 is a pinned revision of the Nixpkgs repo, defined in another overlay. My current Nix config has pinned Nixpkgs versions going back to 2016. For example, here's a bunch of such overrides:

https://github.com/Warbo/nix-config/blob/master/overrides/fi...

At the moment I'm using niv to manage the pinned Nixpkgs versions (the 'repoXXXX' entries):

https://github.com/Warbo/nix-helpers/blob/master/nix/sources...

https://github.com/nix-community/nixos-generators

Those Linode instructions are about installing an OS from an installation ISO from Linode's rescue mode. -- I'd consider that more a 'plus' to Linode that you get to be able to install whatever unsupported Linux on Linode's VMs. But, of course it's not as smooth as the officially supported images.

Sibling comment mentions that NixOS provides ways to build VM images (e.g. https://github.com/nix-community/nixos-generators has a generator specifically for Linode).

Another option is to use nixos-infect, which will replace a Linux distribution with a NixOS distribution. https://github.com/elitak/nixos-infect

> At that point, I feel like all of the repeatability gains are gone. If I want to spin up a fresh server, I have to read a guide and set stuff up by hand?

Just as with ansible, "git pull to deploy". You'd keep a copy of your NixOS configuration.nix somewhere else, and would be able to apply it later.

> it really does let me just get a new VPS and deploy to it very fast

Using a tool you're familiar with to get the job done is going to be faster than learning to use a tool you're unfamiliar with.

I believe much of the use of NixOS is for hobby stuff, and for personal machines. (c.f. "In what environments do you use Nix", Development (1242) vs Home Server (845) vs Production (386) https://discourse.nixos.org/t/2022-nix-survey-results/18983).

If you need to generate lxc container in NixOS then perhaps this repo might be useful: https://github.com/nix-community/nixos-generators this article uses it https://www.thedroneely.com/posts/running-nixos-linux-containers/

You might wanna check out nix-community/nixos-generators, it’s maintained by the same dude as Disko

You can look at nixos-generators for support code that well let you take existing configs and build a variety of bootable images from them.

You should take a look at NixOS Generators, it's a flake with configs to build common formats like ISO, LXC, Docker, etc. I use that to generate an ISO with my config, specifically the packages.iso section.

I am trying to make use of https://github.com/nix-community/nixos-generators to generate qcow2 images from a NixOs configuration. Since it will be used with Scaleway, they require an efi bootable image.

I haven't migrated machines from one vm provider to vmware, but I have provided a number of pregenerated nixos images (along the line of https://github.com/nix-community/nixos-generators) to clients to install onto vmware (and other - hyperv, xen, qemu, physical) hosts.