lenovo-x1: compress images using zstd

This avoids having images on the builders and cache take too much
storage.

Signed-off-by: Humaid Alqasimi <humaid.alqassimi@tii.ae>

modules/disko/lenovo-x1-disko-basic.nix

@@ -3,7 +3,7 @@
 # Example to create a bios compatible gpt partition
 # To use this example, you will need to specify a device i.e.
 #   { disko.devices.disk1.device = "/dev/sda"; }
-{
+{pkgs, ...}: {
   disko.devices = {
     disk.disk1 = {
       type = "disk";
@@ -59,5 +59,11 @@
       };
     };
   };
-  disko.memSize = 2048;
+  disko = {
+    memSize = 2048;
+    extraPostVM = ''
+      ${pkgs.zstd}/bin/zstd --compress $out/*raw
+      rm $out/*raw
+    '';
+  };
 }

packages/installer/ghaf-installer.sh

@@ -28,7 +28,7 @@ read -r -p "Device name [e.g. /dev/nvme0n1]: " DEVICE_NAME
 read -r -p 'WARNING: Next command will destroy all previous data from your device, press Enter to proceed. '
 
 echo "Installing..."
-dd if=@imagePath@ of="${DEVICE_NAME}" bs=32M status=progress
+zstdcat @imagePath@ | dd of="${DEVICE_NAME}" bs=32M status=progress
 
 echo ""
 echo "Installation done. Please remove the installation media and reboot"

targets/lenovo-x1-installer/flake-module.nix

@@ -10,7 +10,7 @@
   name = "lenovo-x1-carbon";
   system = "x86_64-linux";
   installer = generation: variant: let
-    imagePath = self.packages.x86_64-linux."${name}-${generation}-${variant}" + "/disk1.raw";
+    imagePath = self.packages.x86_64-linux."${name}-${generation}-${variant}" + "/disk1.raw.zst";
     hostConfiguration = lib.nixosSystem {
       inherit system;
       modules = [
@@ -39,6 +39,8 @@
             installScript
           ];
 
+          isoImage.squashfsCompression = "zstd -Xcompression-level 3";
+
           # NOTE: Stop nixos complains about "warning:
           # mdadm: Neither MAILADDR nor PROGRAM has been set. This will cause the `mdmon` service to crash."
           # https://github.com/NixOS/nixpkgs/blob/master/nixos/modules/profiles/installation-device.nix#L112