set installer version as part of build step

launcher/image/preload.sh

@@ -3,6 +3,7 @@
 readonly OEM_PATH='/usr/share/oem'
 readonly CS_PATH="${OEM_PATH}/confidential_space"
 readonly EXPERIMENTS_BINARY="confidential_space_experiments"
+readonly GPU_INSTALLER_IMAGE_REF="cos_gpu_installer_image_reference"
 
 copy_launcher() {
   cp launcher "${CS_PATH}/cs_container_launcher"
@@ -19,6 +20,10 @@ setup_launcher_systemd_unit() {
   cp exit_script.sh "${CS_PATH}/exit_script.sh"
 }
 
+set_cos_gpu_installer_image_reference() {
+  cos-extensions list -- --gpu-installer >> "${CS_PATH}"/"${GPU_INSTALLER_IMAGE_REF}"
+}
+
 append_cmdline() {
   local arg="$1"
   if [[ ! -d /mnt/disks/efi ]]; then
@@ -116,6 +121,7 @@ main() {
   append_cmdline "cos.protected_stateful_partition=m"
   # Increase wait timeout of the protected stateful partition.
   append_cmdline "systemd.default_timeout_start_sec=900s"
+  set_cos_gpu_installer_image_reference
 
   if [[ "${IMAGE_ENV}" == "debug" ]]; then
     configure_systemd_units_for_debug

launcher/internal/gpu/config.go

@@ -5,4 +5,6 @@ const (
 	InstallationHostDir = "/var/lib/nvidia"
 	// InstallationContainerDir is the directory where gpu drivers will be available on the workload container.
 	InstallationContainerDir = "/usr/local/nvidia"
+	// GpuInstallerImageReferenceFile is a filename which has the container image reference of cos_gpu_installer.
+	GpuInstallerImageReferenceFile = "cos_gpu_installer_image_reference"
 )

launcher/internal/gpu/driverinstaller.go

@@ -7,13 +7,15 @@ import (
 	"log"
 	"os"
 	"os/exec"
+	"path"
 	"strings"
 
 	"cos.googlesource.com/cos/tools.git/src/cmd/cos_gpu_installer/deviceinfo"
 	"github.com/containerd/containerd"
 	"github.com/containerd/containerd/cio"
 	"github.com/containerd/containerd/namespaces"
 	"github.com/containerd/containerd/oci"
+	"github.com/google/go-tpm-tools/launcher/launcherfile"
 	"github.com/google/go-tpm-tools/launcher/spec"
 	"github.com/opencontainers/runtime-spec/specs-go"
 )
@@ -147,11 +149,12 @@ func (di *DriverInstaller) InstallGPUDrivers(ctx context.Context) error {
 }
 
 func getInstallerImageReference() (string, error) {
-	installerImageRefBytes, err := exec.Command("cos-extensions", "list", "--", "--gpu-installer").Output()
+	referenceFile := path.Join(launcherfile.HostTmpPath, GpuInstallerImageReferenceFile)
+	imageRefBytes, err := os.ReadFile(referenceFile)
 	if err != nil {
 		return "", fmt.Errorf("failed to get the cos-gpu-installer version: %v", err)
 	}
-	installerImageRef := strings.TrimSpace(string(installerImageRefBytes))
+	installerImageRef := strings.TrimSpace(string(imageRefBytes))
 	return installerImageRef, nil
 }