Merge pull request #6874 from priyawadhwa/skip-cache

Only cache k8s images if necessary

pkg/minikube/node/start.go

@@ -29,6 +29,7 @@ import (
 	"k8s.io/minikube/pkg/minikube/localpath"
 	"k8s.io/minikube/pkg/minikube/logs"
 	"k8s.io/minikube/pkg/minikube/out"
+	"k8s.io/minikube/pkg/minikube/preload"
 	"k8s.io/minikube/pkg/util"
 )
 
@@ -45,7 +46,10 @@ func Start(mc config.ClusterConfig, n config.Node, primary bool, existingAddons
 	}
 	// Now that the ISO is downloaded, pull images in the background while the VM boots.
 	var cacheGroup errgroup.Group
-	beginCacheRequiredImages(&cacheGroup, mc.KubernetesConfig.ImageRepository, k8sVersion)
+	skipCacheImages := driver.IsKIC(driverName) && preload.TarballExists(k8sVersion, mc.KubernetesConfig.ContainerRuntime)
+	if !skipCacheImages {
+		beginCacheRequiredImages(&cacheGroup, mc.KubernetesConfig.ImageRepository, k8sVersion)
+	}
 
 	// Abstraction leakage alert: startHost requires the config to be saved, to satistfy pkg/provision/buildroot.
 	// Hence, saveConfig must be called before startHost, and again afterwards when we know the IP.

pkg/minikube/preload/preload.go

@@ -67,6 +67,17 @@ func remoteTarballURL(k8sVersion string) string {
 	return fmt.Sprintf("https://storage.googleapis.com/%s/%s", constants.PreloadedVolumeTarballsBucket, tarballName(k8sVersion))
 }
 
+// TarballExists returns true if there is a preloaded tarball
+// that can be used
+func TarballExists(k8sVersion, containerRuntime string) bool {
+	if containerRuntime != "docker" {
+		return false
+	}
+	url := remoteTarballURL(k8sVersion)
+	_, err := http.Head(url)
+	return err == nil
+}
+
 // CacheTarball caches the preloaded images tarball on the host machine
 func CacheTarball(k8sVersion, containerRuntime string) error {
 	if containerRuntime != "docker" {
@@ -81,15 +92,14 @@ func CacheTarball(k8sVersion, containerRuntime string) error {
 		}
 	}
 
-	url := remoteTarballURL(k8sVersion)
-
 	// Make sure we support this k8s version
-	if _, err := http.Get(url); err != nil {
-		glog.Infof("Unable to get response from %s, skipping downloading: %v", url, err)
+	if !TarballExists(k8sVersion, containerRuntime) {
+		glog.Infof("Preloaded tarball for k8s version %s does not exist", k8sVersion)
 		return nil
 	}
 
 	out.T(out.FileDownload, "Downloading preloaded images tarball for k8s {{.version}} ...", out.V{"version": k8sVersion})
+	url := remoteTarballURL(k8sVersion)
 	client := &getter.Client{
 		Src:     url,
 		Dst:     targetFilepath,