added overlay2 to preloaded images tarball name

Makefile

@@ -524,8 +524,8 @@ kic-base-image: ## builds the base image used for kic.
 
 .PHONY: upload-preloaded-images-tar
 upload-preloaded-images-tar: generate-preloaded-images-tar # Upload the preloaded images tar to the GCS bucket. Specify a specific kubernetes version to build via `KUBERNETES_VERSION=vx.y.z make upload-preloaded-images-tar`.
-	gsutil cp out/preloaded-images-k8s-${KUBERNETES_VERSION}.tar.lz4 gs://${PRELOADED_VOLUMES_GCS_BUCKET}
-	gsutil acl ch -u AllUsers:R gs://${PRELOADED_VOLUMES_GCS_BUCKET}/preloaded-images-k8s-${KUBERNETES_VERSION}.tar.lz4 
+	gsutil cp out/preloaded-images-k8s-${KUBERNETES_VERSION}-overlay2.tar.lz4 gs://${PRELOADED_VOLUMES_GCS_BUCKET}
+	gsutil acl ch -u AllUsers:R gs://${PRELOADED_VOLUMES_GCS_BUCKET}/preloaded-images-k8s-${KUBERNETES_VERSION}-overlay2.tar.lz4 
 
 .PHONY: generate-preloaded-images-tar
 generate-preloaded-images-tar:

hack/preload-images/preload_images.go

@@ -22,6 +22,7 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
+	"strings"
 
 	"github.com/pkg/errors"
 	"k8s.io/minikube/pkg/drivers/kic"
@@ -37,17 +38,24 @@ const (
 )
 
 var (
-	kubernetesVersion = ""
-	tarballFilename   = ""
+	kubernetesVersion   = ""
+	tarballFilename     = ""
+	dockerStorageDriver = ""
 )
 
 func init() {
 	flag.StringVar(&kubernetesVersion, "kubernetes-version", "", "desired kubernetes version, for example `v1.17.2`")
+	flag.StringVar(&dockerStorageDriver, "docker-storage-driver", "overlay2", "docker storage driver backend")
+
 	flag.Parse()
-	tarballFilename = fmt.Sprintf("preloaded-images-k8s-%s.tar.lz4", kubernetesVersion)
+	tarballFilename = fmt.Sprintf("preloaded-images-k8s-%s-%s.tar.lz4", kubernetesVersion, dockerStorageDriver)
 }
 
 func main() {
+	if err := verifyDockerStorage(); err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
 	if err := executePreloadImages(); err != nil {
 		fmt.Println(err)
 		os.Exit(1)
@@ -143,3 +151,16 @@ func deleteMinikube() error {
 	cmd.Stdout = os.Stdout
 	return cmd.Run()
 }
+
+func verifyDockerStorage() error {
+	cmd := exec.Command("docker", "info", "-f", "{{.Info.Driver}}")
+	output, err := cmd.Output()
+	if err != nil {
+		return err
+	}
+	driver := strings.Trim(string(output), " \n")
+	if driver != dockerStorageDriver {
+		return fmt.Errorf("docker storage driver %s does not match requested %s", driver, dockerStorageDriver)
+	}
+	return nil
+}

pkg/drivers/kic/kic.go

@@ -103,9 +103,10 @@ func (d *Driver) Create() error {
 	glog.Infof("Starting extracting preloaded images to volume")
 	// Extract preloaded images to container
 	if err := oci.ExtractTarballToVolume(preload.TarballFilepath(d.NodeConfig.KubernetesVersion), params.Name, BaseImage); err != nil {
-		return errors.Wrap(err, "extracting tarball to volume")
+		glog.Infof("Unable to extract preloaded tarball to volume: %v", err)
+	} else {
+		glog.Infof("Took %f seconds to extract preloaded images to volume", time.Since(t).Seconds())
 	}
-	glog.Infof("Took %f seconds to extract preloaded images to volume", time.Since(t).Seconds())
 
 	return nil
 }

pkg/minikube/preload/preload.go

@@ -39,12 +39,12 @@ import (
 
 // returns name of the tarball
 func tarballName(k8sVersion string) string {
-	return fmt.Sprintf("preloaded-images-k8s-%s.tar.lz4", k8sVersion)
+	return fmt.Sprintf("preloaded-images-k8s-%s-overlay2.tar.lz4", k8sVersion)
 }
 
 // returns the name of the checksum file
 func checksumName(k8sVersion string) string {
-	return fmt.Sprintf("preloaded-images-k8s-%s.tar.lz4.checksum", k8sVersion)
+	return fmt.Sprintf("preloaded-images-k8s-%s-overlay2.tar.lz4.checksum", k8sVersion)
 }
 
 // returns target dir for all cached items related to preloading