Enable flakes in kexec image and comma integration

flake.nix

@@ -145,11 +145,15 @@
           machineHosts;
 
       packages =
+        with inputs;
         let
-          mkEphemeral = system: format: inputs.nixos-generators.nixosGenerate {
+          mkEphemeral = system: format: nixos-generators.nixosGenerate {
             inherit system;
             inherit format;
-            modules = [ ./machines/ephemeral/minimal.nix ];
+            modules = [
+              ./machines/ephemeral/minimal.nix
+              nix-index-database.nixosModules.default
+            ];
           };
         in
         {

machines/ephemeral/minimal.nix

@@ -5,6 +5,8 @@
     (modulesPath + "/installer/cd-dvd/channel.nix")
     ../../common/machine-info
     ../../common/ssh.nix
+    ../../common/flakes.nix
+    ../../common/shell.nix
   ];
 
   boot.initrd.availableKernelModules = [
@@ -36,6 +38,7 @@
     git-lfs
     wget
     htop
+    btop
     dnsutils
     pciutils
     usbutils
@@ -54,5 +57,7 @@
     };
   };
 
+  nix.flakes.enable = true;
+
   users.users.root.openssh.authorizedKeys.keys = config.machines.ssh.userKeys;
 }