Validation PVs for mount options

We are going to move the validation in its own package
and we will be calling validation for individual volume types
as needed.

pkg/volume/validation/pv_validation.go

@@ -0,0 +1,58 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package validation
+
+import (
+	"k8s.io/apimachinery/pkg/util/validation/field"
+	"k8s.io/kubernetes/pkg/api"
+)
+
+// MountOptionAnnotation defines mount option annotation used in PVs
+const MountOptionAnnotation = "volume.beta.kubernetes.io/mount-options"
+
+// ValidatePersistentVolume validates PV object for plugin specific validation
+// We can put here validations which are specific to volume types.
+func ValidatePersistentVolume(pv *api.PersistentVolume) field.ErrorList {
+	return checkMountOption(pv)
+}
+
+func checkMountOption(pv *api.PersistentVolume) field.ErrorList {
+	allErrs := field.ErrorList{}
+	// if PV is of these types we don't return errors
+	// since mount options is supported
+	if pv.Spec.GCEPersistentDisk != nil ||
+		pv.Spec.AWSElasticBlockStore != nil ||
+		pv.Spec.Glusterfs != nil ||
+		pv.Spec.NFS != nil ||
+		pv.Spec.RBD != nil ||
+		pv.Spec.Quobyte != nil ||
+		pv.Spec.ISCSI != nil ||
+		pv.Spec.Cinder != nil ||
+		pv.Spec.CephFS != nil ||
+		pv.Spec.AzureFile != nil ||
+		pv.Spec.VsphereVolume != nil ||
+		pv.Spec.AzureDisk != nil ||
+		pv.Spec.PhotonPersistentDisk != nil {
+		return allErrs
+	}
+	// any other type if mount option is present lets return error
+	if _, ok := pv.Annotations[MountOptionAnnotation]; ok {
+		metaField := field.NewPath("metadata")
+		allErrs = append(allErrs, field.Forbidden(metaField.Child("annotations", MountOptionAnnotation), "may not specify mount options for this volume type"))
+	}
+	return allErrs
+}