Add cross-platform Nix flake bootstrap

Adds a flake providing shared modules for NixOS and standalone
home-manager, a copyable NixOS host template, and the OpenSpec
tooling/change scaffolding used to plan this work.

1 files changed, 23 insertions, 0 deletions

diff --git a/modules/nixos/common.nix b/modules/nixos/common.nix
new file mode 100644
index 0000000..5427414
--- /dev/null
+++ b/modules/nixos/common.nix
@@ -0,0 +1,23 @@
+{ pkgs, lib, ... }:
+{
+  nix.settings.experimental-features = [ "nix-command" "flakes" ];
+
+  nix.gc = {
+    automatic = true;
+    dates = "weekly";
+    options = "--delete-older-than 30d";
+  };
+
+  # Per-host configuration.nix can override either of these without
+  # conflicting, since they're set with mkDefault here.
+  time.timeZone = lib.mkDefault "Etc/UTC";
+  i18n.defaultLocale = lib.mkDefault "en_US.UTF-8";
+
+  programs.zsh.enable = true;
+
+  users.users.tom = {
+    isNormalUser = true;
+    extraGroups = [ "wheel" ];
+    shell = pkgs.zsh;
+  };
+}