Add configs for a new kubernetes cluster on NixOS.

nix/kubernetes/keys/flake.nix

@@ -0,0 +1,31 @@
+{
+  description = "Build keys to manually deploy to kubernetes cluster.";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+  };
+
+  outputs =
+    { self, nixpkgs }:
+    let
+      forAllSystems = nixpkgs.lib.genAttrs nixpkgs.lib.systems.flakeExposed;
+    in
+    {
+      packages = forAllSystems (
+        system:
+        let
+          pkgs = nixpkgs.legacyPackages.${system};
+          appliedOverlay = self.overlays.default pkgs pkgs;
+        in
+        {
+          deploy_script = appliedOverlay.k8s.deploy_script;
+          default = appliedOverlay.k8s.keys;
+        }
+      );
+      overlays.default = (
+        final: prev: {
+          k8s = (final.callPackage ./scope.nix { inherit (final.lib) makeScope; });
+        }
+      );
+    };
+}