nixos/tools: add desktopConfiguration option (to seed configuration into configuration.nix)

[worldofpeace]

Motivation for this change

In 20.09 we added a GNOME ISO. It would be really great if, for all graphical iso's, we seed a configuration that isn't commented and only used in those respective iso's. I believe @samueldr first suggested this on the thread about adding a GNOME ISO. My current disposition is that we should block on this, I think we will have enough time to get this feature in, and it would make having another ISO feel more meaningful. If not, I'm not sure about backporting.

I also cleaned up the configuration.nix a bit, @ttuegel mentioned we should not call plasma "KDE" so I made that change to the generated configuration.nix along with some other things.

I will say, off the bat, the only issue with this is the configuration desktopConfiguration isn't indented properly. Anyone knowing perl or who can spot the mistake (I'm sleepy 😁 ) please mention.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

[worldofpeace]

@ofborg test nixos-generate-config

[samueldr]

Just my 2¢, but I wouldn't block the release on this new feature. If it is deemed to be really desirable, I guess backporting this self-contained feature early in the release process wouldn't be an issue.

It's not like this was a regression, we've been generating the commented-out section for a good while, so going with it for just a bit longer isn't going to cause problems.

[worldofpeace]

Just my 2¢, but I wouldn't block the release on this new feature. If it is deemed to be really desirable, I guess backporting this self-contained feature early in the release process wouldn't be an issue.

It's not like this was a regression, we've been generating the commented-out section for a good while, so going with it for just a bit longer isn't going to cause problems.

I'll take your advice as former RM 👍

[davidak]

Do i understand it correctly that the behavior should be like

1. download GNOME ISO
2. just install
3. have GNOME desktop installed

that sounds very intuitive

[davidak]

Suggested change

	# Enable touchpad support (enabled default in most desktopManager).
	# Enable touchpad support (enabled by default in most desktopManager).

[worldofpeace]

Do i understand it correctly that the behavior should be like

1. download GNOME ISO

2. just install

3. have GNOME desktop installed

that sounds very intuitive

Precisely. The most basic user should have an aligned configuration for the image they have chosen to use

[worldofpeace]

Do i understand it correctly that the behavior should be like

1. download GNOME ISO

2. just install

3. have GNOME desktop installed

that sounds very intuitive

Precisely. The most basic user should have an aligned configuration for the image they have chosen to use

Though I will add that "2. just install" probably won't be a reality because they still have to configure a user manually.

[worldofpeace]

A solution for that, at least at the cli front, is that nixos-generate-config creates a users.nix to be added to the imports of configuration.nix. And maybe it can have some behavior where it prompts you for

• single user multi user creations
• setup password on first boot or immutable users with a hashed password (we could handle the hashing ourselves)
• also add flags on the cli

The "setup password on first boot" is actually an option that a lot gui's I think could accommodate, like I think gnome-initial-setup can do it and in pantheon (maybe if I poke them in a way we could use). That's considered an "OEM type" install and it's actually the most convenient for the enduser for a single user system. Anyways, I'd want to steer from the discussion of having a graphical installer and then just focus on that issue of having a not so intuitive user creation.

---

On that note, nixos-generate-config is an actually confusing name for the tool is it not? It doesn't actually create you a really usable configuration and you can't continue to generate your config with this tool subsequently. What could be ideal is a cli tool to actually generate nix configs. @mkg20001 told me about his tool that basically does exactly this https://github.com/ssd-solar/conf-tool. It has a seed, like I'm trying to do here, but it also has templates that a distributor can setup. While I enjoy this improvement I've made here, it's nothing radical like I really want that could also be fed into making a gui installer actually viable.