cloudstack: add to image/images

This was an oversight in https://github.com/NixOS/nixpkgs/pull/347275,
so it's currently missing from the variants listed in nixos-rebuild build-image

nixos/maintainers/scripts/cloudstack/cloudstack-image.nix

···
 }:
 
 {
-  imports = [ ../../../modules/virtualisation/cloudstack-config.nix ];
+  imports = [
+
+    ../../../modules/virtualisation/cloudstack-config.nix
+    ../../../modules/image/file-options.nix
+  ];
 
+  system.nixos.tags = [ "cloudstack" ];
+  image.extension = "qcow2";
+  system.build.image = config.system.build.cloudstackImage;
   system.build.cloudstackImage = import ../../../lib/make-disk-image.nix {
     inherit lib config pkgs;
+    inherit (config.virtualisation) diskSize;
+    baseName = config.image.baseName;
     format = "qcow2";
     configFile = pkgs.writeText "configuration.nix" ''
       {

nixos/modules/image/images.nix

···
   imageModules = {
     amazon = ../../maintainers/scripts/ec2/amazon-image.nix;
     azure = ../virtualisation/azure-image.nix;
+    cloudstack = ../../maintainers/scripts/cloudstack/cloudstack-image.nix;
     digital-ocean = ../virtualisation/digital-ocean-image.nix;
     google-compute = ../virtualisation/google-compute-image.nix;
     hyperv = ../virtualisation/hyperv-image.nix;

nixos/modules/virtualisation/cloudstack-config.nix

···
   ];
 
   config = {
-    fileSystems."/" = {
+    fileSystems."/" = lib.mkImageMediaOverride {
       device = "/dev/disk/by-label/nixos";
       autoResize = true;
+      fsType = "ext4";
     };
 
     boot.growPartition = true;