Impure nixos on other Linux distro

[holymonson]

I'm using other Linux distro with nixpkgs, and want to switch to NixOS but not entirely. Compare current implements

• nixpkgs, can only manage userspace packages, not system level services like plasma.
• nixos, tyrannically controlling the whole OS and everything.
• nixos with isContainer = true;, boot at stage-2, leave bootloader and mount untouched, but still mess /etc e.g. passwd.

I'm thinking we may split out a stage-3, between container and nixpkgs, to control services only. It should

• leave hardware or filesystem related untouched.
• live alone with other distro same as nixpkgs
• only depends on host's systemd (and kernel)
• don't mess /etc unless we explicitly make config in configuration.nix

This could benefit in

• easier to switch to NixOS. Since new user to NixOS is usually an experienced Linux user who are already running their own Linux, it will take much time to deploy a new OS.
• take advantage of other distro, at least in my view, archlinux's AUR provides more convenience than nixpkgs for many standalone or precompiled packages.
• easier to deploy to SBS like raspberry pi because they may have specific well tuned system.

I have done some test but before pushing further, I want to ask maintainers' options or plans, in case it should be called off in advance.

[veprbl]

Are you aware of https://github.com/nix-community/home-manager ?

[holymonson]

Are you aware of https://github.com/nix-community/home-manager ?

Sadly home-manager is to control user specific (non global) packages, while here we still want nixos to control global packages, but just skip those fundamental skeleton to /etc.

[hmenke]

@holymonson You can use home-manager to manage /etc, see https://gist.github.com/danbst/eb55f9363c0b9151d65271ae6c20f39b

Otherwise maybe something like https://github.com/svanderburg/nix-processmgmt might fit your needs?

[mjlbach]

I would agree it would be nice to have something like nix-darwin for FHS compliant linux systems. I often want to run GUI packages on Fedora (installed via nix, QT packages are especially troublesome) and frequently run into issues where wrappers/paths that are assumed on nixos are absent. Some of this is addressed by nixGL, but a lot of it isn't.

[holymonson]

@hmenke It' not about managing /etc or processes, but staging nixos's operations. For example, here is a configuration

{ config, pkgs, ... }: {
  services.sshd.enable = true;
}

nixos will install openssh and register sshd to enable and start via systemd, this is exactly what I want, neither more nor less.

However, even for the simple configuration above, nixos will run some boot stage implicitly to provide a fundamental Linux, such as to manipulate passwd fstab resolv.conf ssl/certs, which are necessary for pure NixOS in bootstrap. But if we are already running on an impure Linux, those bootstrap stages are redundant and even harmful as they may likely damage to the base Linux.

So here we propose, to add an option to skip those bootstrap stages, let nixos could run on an already bootstraped and prepared Linux, like a bare container.

[holymonson]

gentle ping @vcunat @danbst @adisbladis @zowoq @infinisil , since this may be sort of container-related.

[stale]

I marked this as stale due to inactivity. → More info

[hmenke]

There is now https://github.com/numtide/system-manager but it's still in a very early stage.