addons: when enabling storage-provisioner-gluster, mark other SCs non-default

There can only be one StorageClass be marked as default. When the
storage-provisioner-gluster addon is enabled, users expect it to be the
default StorageClass.

Instead of removing the "is-default" annotation from the other
StorageClasses, set it to "false". This leaves only the "glusterfile"
StorageClass as "is-default".

cmd/minikube/cmd/config/config.go

@@ -198,7 +198,7 @@ var settings = []Setting{
 		name:        "storage-provisioner-gluster",
 		set:         SetBool,
 		validations: []setFn{IsValidAddon},
-		callbacks:   []setFn{EnableOrDisableAddon},
+		callbacks:   []setFn{EnableOrDisableStorageClasses},
 	},
 	{
 		name:        "metrics-server",

cmd/minikube/cmd/config/util.go

@@ -153,3 +153,25 @@ func EnableOrDisableDefaultStorageClass(name, val string) error {
 	}
 	return EnableOrDisableAddon(name, val)
 }
+
+func EnableOrDisableStorageClasses(name, val string) error {
+	enable, err := strconv.ParseBool(val)
+	if err != nil {
+		return errors.Wrap(err, "Error parsing boolean")
+	}
+
+	// Only StorageClass for 'name' should stay enabled
+	if enable {
+		class := "standard"
+		if name == "storage-provisioner-gluster" {
+			class = "glusterfile"
+		}
+
+		err := storageclass.DisableAllOtherStorageClasses(class)
+		if err != nil {
+			return errors.Wrap(err, "Error disabling storage classes")
+		}
+	}
+
+	return EnableOrDisableAddon(name, val)
+}

deploy/addons/storage-provisioner-gluster/storage-provisioner-glusterfile.yaml

@@ -7,6 +7,8 @@ metadata:
     k8s-app: storage-provisioner-gluster
     kubernetes.io/minikube-addons: storage-provisioner-gluster
     addonmanager.kubernetes.io/mode: Reconcile
+  annotations:
+    storageclass.beta.kubernetes.io/is-default-class: "true"
 provisioner: gluster.org/glusterfile
 reclaimPolicy: Delete
 parameters:

pkg/minikube/storageclass/storageclass.go

@@ -46,3 +46,34 @@ func DisableDefaultStorageClass() error {
 
 	return nil
 }
+
+func DisableAllOtherStorageClasses(name string) error {
+	loadingRules := clientcmd.NewDefaultClientConfigLoadingRules()
+	kubeConfig := clientcmd.NewNonInteractiveDeferredLoadingClientConfig(loadingRules, &clientcmd.ConfigOverrides{})
+	config, err := kubeConfig.ClientConfig()
+	if err != nil {
+		return errors.Wrap(err, "Error creating kubeConfig")
+	}
+	client, err := kubernetes.NewForConfig(config)
+	if err != nil {
+		return errors.Wrap(err, "Error creating new client from kubeConfig.ClientConfig()")
+	}
+
+	scList, err := client.Storage().StorageClasses().List(metav1.ListOptions{})
+	if err != nil {
+		return errors.Wrap(err, "Error listing StorageClasses")
+	}
+
+	for _, sc := range scList.Items {
+		if sc.Name == name {
+			continue
+		}
+
+		err = client.Storage().StorageClasses().Delete(sc.Name, &metav1.DeleteOptions{})
+		if err != nil {
+			return errors.Wrapf(err, "Error deleting storage class %s", sc.Name)
+		}
+	}
+
+	return nil
+}