check for preloaded images before loading again

hack/preload-images/preload_images.go

@@ -119,7 +119,7 @@ func executePreloadImages() error {
 }
 
 func createImageTarball() error {
-	cmd := exec.Command("docker", "exec", profile, "sudo", "tar", "-I", "lz4", "-C", "/var/lib/docker", "-cvf", tarballFilename, "./")
+	cmd := exec.Command("docker", "exec", profile, "sudo", "tar", "-I", "lz4", "-C", "/var", "-cvf", tarballFilename, "./lib/docker")
 	cmd.Stdout = os.Stdout
 	if err := cmd.Run(); err != nil {
 		return errors.Wrap(err, "creating image tarball")

pkg/minikube/machine/cache_images.go

@@ -19,8 +19,10 @@ package machine
 import (
 	"fmt"
 	"os"
+	"os/exec"
 	"path"
 	"path/filepath"
+	"strings"
 	"sync"
 	"time"
 
@@ -62,6 +64,12 @@ func CacheImagesForBootstrapper(imageRepository string, version string, clusterB
 
 // LoadImages loads previously cached images into the container runtime
 func LoadImages(cc *config.ClusterConfig, runner command.Runner, images []string, cacheDir string) error {
+	// Skip loading images if images already exist
+	if imagesPreloaded(runner, images) {
+		glog.Infof("Images are preloaded, skipping loading")
+		return nil
+	}
+
 	glog.Infof("LoadImages start: %s", images)
 	start := time.Now()
 
@@ -99,6 +107,28 @@ func LoadImages(cc *config.ClusterConfig, runner command.Runner, images []string
 	return nil
 }
 
+func imagesPreloaded(runner command.Runner, images []string) bool {
+	rr, err := runner.RunCmd(exec.Command("docker", "images", "--format", "{{.Repository}}:{{.Tag}}"))
+	if err != nil {
+		return false
+	}
+	preloadedImages := map[string]struct{}{}
+	for _, i := range strings.Split(rr.Stdout.String(), "\n") {
+		preloadedImages[i] = struct{}{}
+	}
+
+	glog.Infof("Got preloaded images: %s", rr.Output())
+
+	// Make sure images == imgs
+	for _, i := range images {
+		if _, ok := preloadedImages[i]; !ok {
+			glog.Infof("%s wasn't preloaded", i)
+			return false
+		}
+	}
+	return true
+}
+
 // needsTransfer returns an error if an image needs to be retransfered
 func needsTransfer(imgClient *client.Client, imgName string, cr cruntime.Manager) error {
 	imgDgst := ""         // for instance sha256:7c92a2c6bbcb6b6beff92d0a940779769c2477b807c202954c537e2e0deb9bed