doc: quickstart "ISO. What next?"

[blaggacao]

Given one started to plan an environment with devos:

There is a bit of a gap between flashing the ISO of a new host onto a stick and fully managing a host either locally (after having set up network and access rights and cloned the repo onto it) or remotely via deployrs (after having bootstrapped identity and ssh access).

Related: #132 (comment)

documenting my journey so far:

1. flk iso MyNewHost
2. dd ...
3. boot into iso on target host
4. follow https://nixos.org/manual/nixos/stable/index.html#sec-installation-partitioning
5. 1), 2) & 3) of https://nixos.org/manual/nixos/stable/index.html#sec-installation-installing, that is:

• mount /dev/disk/by-label/nixos /mnt
• mkdir -p /mnt/boot
• mount /dev/disk/by-label/boot /mnt/boot
• swapon /dev/sda2

6. keep target running off of the usb memory card
7. from original machine: deploy ".#MyNewHost" --hostname 192.168.191.179 --ssh-user nixos & that failed, presumably because according to nixos installer things are to be mounted under /mnt

[blaggacao]

Maybe we should copy over the current local devos repo onto the iso image like so:

{
    isoImage.contents =
      [
        { source = self;
          target = "/devos/"; # or self.name (if that was to exist)
        }
      ];
}

next to : /~https://github.com/divnix/devos/blob/d7f15a664d20de910611a29167107aee8ff0dbab/lib/devos/devosSystem.nix#L15

Maybe even a little more magic can be done with the help of storeContent so that the flk command proper is available on a live cd... That would be really cool. See the iso module option:

{    isoImage.storeContents = mkOption {
      example = literalExample "[ pkgs.stdenv ]";
      description = ''
        This option lists additional derivations to be included in the
        Nix store in the generated ISO image.
      '';
    };
}

Off topic:
Do we have a branded splash image?

Documenting in preparation of PR:

$ cd /iso/devos
$ nix develop
$ flk install MyNewHost --impure

Why the heck is it --impure? I was getting access to path '/mnt/nix/...' is forbidden in restricted mode.

[Pacman99]

Somewhat unrelated, but if I created an iso from my server's config which has random systemd services(minecraft, matrix, ...). Will those services startup when I boot from the iso? Because it would be really annoying if a bunch of services starting setting up databases and taking up ram while I'm running through the install. But I still want those applications to exist for easy installation.

[blaggacao]

Will those services startup when I boot from the iso?

Yes. And indeed that is something that needs more thought, still.

[Pacman99]

Perhaps as you add the devos source you could remove the modules ++ line. And maybe just add self.packages to environment.systemPackages. Not entirely sure what the best solution is. And I think it should be clarified what the goal of isoConfig is, is it purely for installation? or is there more that needs to be accomplished.

[blaggacao]

This is gold price input. Let's safe it for a follow up issue / pr though.

[Pacman99]

Really looking forward to being able to easily build ISO's for bootstrapping a machine!