nixos: create 'modules/nixos' folder

Let's consolidate all modules under one path, so that NixOS,
home-manager, and nix-darwin (if I ever end up using it down the line)
would go under the same folder.

modules/nixos/secrets/default.nix

@@ -0,0 +1,24 @@
+{ config, inputs, lib, ... }:
+
+{
+  imports = [
+    inputs.agenix.nixosModules.age
+  ];
+
+  config.age = {
+    secrets =
+      let
+        toName = lib.removeSuffix ".age";
+        userExists = u: builtins.hasAttr u config.users.users;
+        # Only set the user if it exists, to avoid warnings
+        userIfExists = u: if userExists u then u else "root";
+        toSecret = name: { owner ? "root", ... }: {
+          file = ./. + "/${name}";
+          owner = lib.mkDefault (userIfExists owner);
+        };
+        convertSecrets = n: v: lib.nameValuePair (toName n) (toSecret n v);
+        secrets = import ./secrets.nix;
+      in
+      lib.mapAttrs' convertSecrets secrets;
+  };
+}

modules/nixos/secrets/secrets.nix

@@ -0,0 +1,10 @@
+# Common secrets
+let
+  keys = import ../../keys;
+
+  inherit (keys) all;
+in
+{
+  "users/ambroisie/hashed-password.age".publicKeys = all;
+  "users/root/hashed-password.age".publicKeys = all;
+}

modules/nixos/secrets/users/ambroisie/hashed-password.age

@@ -0,0 +1,9 @@
+age-encryption.org/v1
+-> ssh-ed25519 cKojmg vOaL2ZKsFEjX9mzQvw8Je7x2Dq8cMhrZEyBTXpH4QnE
+HXO4fbWdJsbsRmGq0IYzq8/szObxzpsGfQNNTJ4vNzg
+-> ssh-ed25519 jPowng WPxg0pP6O3ZS4dPc1WcDvzig22Fylk3mR/W9STaWbW4
+GuhFwt7M5Lc38q2LC/0eul0yP60UxmWwi9I8ToHv7bE
+-> :;V8\-grease ZC#7~eR# P<'e?vI3 9R
+lZlb44QiAaIxd0SYiRNT/QRnxxUt7npbksg
+--- 9xv4lt8IcGR8jP0UcKYYnTuh1Ix/pqXgDmevkTH9j1A
+Ï]ºcÓ3óxíwÿ'ã	`<0B>ùhçÒ=X¨í·¢Ç‘g3ÆÆÄ]~ËôÞqÙ.XnÄa*€±W:<3A>–¸±,â©z®vyzñI¦æ }ÂDO=`êw“ñõ¹ˆ7:™ù“ÐRx•5$¨Ö6:ö¨´"õ,HM„<4D>"
_ëÞòMÛMƒœˆBJe‰ùFá