[fugitive] Make config part of deployed system

lib/pkgs/config-archive.nix

@@ -0,0 +1,27 @@
+{ stdenv, gnutar }:
+
+stdenv.mkDerivation rec {
+  name = "config-archive";
+  src = ../../.;
+  outputs = [ "out" ];
+  buildInputs = [ gnutar ];
+
+  buildPhase = ''
+  tar czf config.tar.gz -C $src --exclude-ignore=.gitignore .
+  
+  '';
+
+  installPhase = ''
+  mkdir -p $out/bin
+
+  install config.tar.gz $out
+
+  echo "
+  #!/bin/sh
+
+  tar xzf ${placeholder "out"}/config.tar.gz --one-top-level
+  " >> $out/bin/config-extract
+
+  chmod +x $out/bin/config-extract
+  '';
+}

lib/systems/fugitive/default.nix

@@ -39,6 +39,10 @@
     ];
   };
 
+  environment.systemPackages = with pkgs; [
+    config-archive
+  ];
+
   boot.loader.systemd-boot.enable = true;
   boot.loader.efi.canTouchEfiVariables = true;