Custom ISO Installer

mmport80 · May 19, 2022, 8:34am

How difficult would it be to create an installer that:

sets up a machine?
without internet?

I see here a way to automate the partitioning step:

Xe/nixos-configs/blob/f80fca40b6ffc23b65ec09e2712ffde39baa66ae/media/autoinstall/iso.nix

{ config, pkgs, lib, ... }: {
  systemd.services.install = {
    description = "Bootstrap a NixOS installation";
    wantedBy = [ "multi-user.target" ];
    after = [ "network.target" "polkit.service" ];
    path = [ "/run/current-system/sw/" ];
    script = with pkgs; ''
        echo 'journalctl -fb -n100 -uinstall' >>~nixos/.bash_history

        set -eux

        dev=/dev/vda

        ${utillinux}/bin/sfdisk --wipe=always $dev <<-END
          label: mbr

          name=NIXOS
        END
        mkfs.ext4 -L nixos ''${dev}1

This file has been truncated. show original

then

a) the hardware is known beforehand (I do nixos-generate-config?)

b) copy over my custom configuration.nix as in the code above.

c) build (I cannot pre-generate the binary because I don’t know the hardware).

I must ensure I have everything I need on the ISO (no internet). Somehow I need to be able to reference packages on the ISO.

Maybe there is an easier way though?

mmport80 · May 19, 2022, 9:02am

Maybe it’s easier to do the install in a few manual steps:

Automate partitioning and nixos-generation.
Then copy the generated configuration & hardware files to a USB
Build system on a remote machine
Copy back to initial machine, and switch

The main difficulty I had with initial sketch above is the unpredictable interface names (and disks). Probably automatable, unsure how much work.