nix: Make nix the root

Which means now I'll have to think about real prefixes in commit names.

os/common.nix

@@ -0,0 +1,78 @@
+{ pkgs, lib, ... }:
+{
+  networking.domain = "geoffrey.frogeye.fr";
+
+  boot.loader.efi.canTouchEfiVariables = true;
+
+  time.timeZone = "Europe/Amsterdam";
+
+  # TODO qwerty-fr for console
+
+  # Enable CUPS to print documents
+  services.printing.enable = true;
+
+  # Enable passwordless sudo
+  security.sudo.extraRules = [{
+    groups = [ "wheel" ];
+    commands = [{
+      command = "ALL";
+      options = [ "NOPASSWD" ];
+    }];
+  }];
+
+  environment.systemPackages = with pkgs; [
+    wget
+    kexec-tools
+    openvpn
+    update-resolv-conf # TODO Is it what I think it is?
+
+    # android tools
+    android-udev-rules
+
+    # Needed for all the fetchFromGit in this repo on nixos-rebuild
+    git
+  ];
+
+  nixpkgs.config.allowUnfree = true;
+
+  programs = {
+    # Enable compilation cache
+    ccache.enable = true;
+    # TODO Not enough, see https://nixos.wiki/wiki/CCache.
+    # Might want to see if it's worth using on NixOS
+    gnupg.agent.enable = true;
+
+    # Let users mount disks
+    udevil.enable = true;
+  };
+
+  services = {
+    # Enable the OpenSSH daemon
+    openssh.enable = true;
+
+    # Time sychronisation
+    chrony = {
+      enable = true;
+      servers = map (n: "${toString n}.europe.pool.ntp.org") (lib.lists.range 0 3);
+      extraConfig = "rtcsync"; # See 23.11 release notes
+    };
+
+    # Prevent power button from shutting down the computer.
+    # On Pinebook it's too easy to hit,
+    # on others I sometimes turn it off when unsuspending.
+    logind.extraConfig = "HandlePowerKey=ignore";
+
+  };
+
+  # FIXME services.openvpn.servers.<name>.updateResolvConf=true
+  # For profiles in the extensions
+
+  # TODO Hibernation?
+
+  # TEST
+  system.copySystemConfiguration = true;
+
+  # Use defaults from
+  system.stateVersion = "23.05";
+
+}