Add VolumeType api to PV and PVC

hack/import-restrictions.yaml

 - baseImportPath: "./pkg/apis/core/"
   allowedImports:
   - k8s.io/apimachinery
+  - k8s.io/apiserver/pkg/util/feature
   - k8s.io/kubernetes/pkg/apis/core
+  - k8s.io/kubernetes/pkg/features
   - k8s.io/kubernetes/pkg/util
   - k8s.io/api/core/v1
 

pkg/api/persistentvolume/util.go

@@ -17,7 +17,9 @@ limitations under the License.
 package persistentvolume
 
 import (
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	api "k8s.io/kubernetes/pkg/apis/core"
+	"k8s.io/kubernetes/pkg/features"
 )
 
 func getClaimRefNamespace(pv *api.PersistentVolume) string {
@@ -96,3 +98,11 @@ func VisitPVSecretNames(pv *api.PersistentVolume, visitor Visitor) bool {
 	}
 	return true
 }
+
+// DropDisabledAlphaFields removes disabled fields from the pv spec.
+// This should be called from PrepareForCreate/PrepareForUpdate for all resources containing a pv spec.
+func DropDisabledAlphaFields(pvSpec *api.PersistentVolumeSpec) {
+	if !utilfeature.DefaultFeatureGate.Enabled(features.BlockVolume) {
+		pvSpec.VolumeMode = nil
+	}
+}

pkg/api/persistentvolume/util_test.go

@@ -24,7 +24,9 @@ import (
 
 	"k8s.io/apimachinery/pkg/util/sets"
 	"k8s.io/apimachinery/pkg/util/validation/field"
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	api "k8s.io/kubernetes/pkg/apis/core"
+	"k8s.io/kubernetes/pkg/features"
 )
 
 func TestPVSecrets(t *testing.T) {
@@ -204,3 +206,62 @@ func collectSecretPaths(t *testing.T, path *field.Path, name string, tp reflect.
 
 	return secretPaths
 }
+
+func newHostPathType(pathType string) *api.HostPathType {
+	hostPathType := new(api.HostPathType)
+	*hostPathType = api.HostPathType(pathType)
+	return hostPathType
+}
+
+func TestDropAlphaPVVolumeMode(t *testing.T) {
+	vmode := api.PersistentVolumeFilesystem
+
+	// PersistentVolume with VolumeMode set
+	pv := api.PersistentVolume{
+		Spec: api.PersistentVolumeSpec{
+			AccessModes: []api.PersistentVolumeAccessMode{api.ReadWriteOnce},
+			PersistentVolumeSource: api.PersistentVolumeSource{
+				HostPath: &api.HostPathVolumeSource{
+					Path: "/foo",
+					Type: newHostPathType(string(api.HostPathDirectory)),
+				},
+			},
+			StorageClassName: "test-storage-class",
+			VolumeMode:       &vmode,
+		},
+	}
+
+	// Enable alpha feature BlockVolume
+	err1 := utilfeature.DefaultFeatureGate.Set("BlockVolume=true")
+	if err1 != nil {
+		t.Fatalf("Failed to enable feature gate for BlockVolume: %v", err1)
+	}
+
+	// now test dropping the fields - should not be dropped
+	DropDisabledAlphaFields(&pv.Spec)
+
+	// check to make sure VolumeDevices is still present
+	// if featureset is set to true
+	if utilfeature.DefaultFeatureGate.Enabled(features.BlockVolume) {
+		if pv.Spec.VolumeMode == nil {
+			t.Error("VolumeMode in pv.Spec should not have been dropped based on feature-gate")
+		}
+	}
+
+	// Disable alpha feature BlockVolume
+	err := utilfeature.DefaultFeatureGate.Set("BlockVolume=false")
+	if err != nil {
+		t.Fatalf("Failed to disable feature gate for BlockVolume: %v", err)
+	}
+
+	// now test dropping the fields
+	DropDisabledAlphaFields(&pv.Spec)
+
+	// check to make sure VolumeDevices is nil
+	// if featureset is set to false
+	if !utilfeature.DefaultFeatureGate.Enabled(features.BlockVolume) {
+		if pv.Spec.VolumeMode != nil {
+			t.Error("DropDisabledAlphaFields VolumeMode for pv.Spec failed")
+		}
+	}
+}

pkg/api/persistentvolumeclaim/BUILD

+package(default_visibility = ["//visibility:public"])
+
+load(
+    "@io_bazel_rules_go//go:def.bzl",
+    "go_library",
+    "go_test",
+)
+
+go_library(
+    name = "go_default_library",
+    srcs = ["util.go"],
+    deps = ["//pkg/api:go_default_library"],
+)
+
+filegroup(
+    name = "package-srcs",
+    srcs = glob(["**"]),
+    tags = ["automanaged"],
+    visibility = ["//visibility:private"],
+)
+
+filegroup(
+    name = "all-srcs",
+    srcs = [":package-srcs"],
+    tags = ["automanaged"],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["util_test.go"],
+    library = ":go_default_library",
+    deps = [
+        "//pkg/api:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/util/sets:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/util/validation/field:go_default_library",
+    ],
+)

pkg/api/persistentvolumeclaim/OWNERS

+reviewers:
+- smarterclayton
+- jsafrane
+- david-mcmahon

pkg/api/persistentvolumeclaim/util.go

+/*
+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 persistentvolumeclaim
+
+import (
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
+	"k8s.io/kubernetes/pkg/apis/core"
+	"k8s.io/kubernetes/pkg/features"
+)
+
+// DropDisabledAlphaFields removes disabled fields from the pvc spec.
+// This should be called from PrepareForCreate/PrepareForUpdate for all resources containing a pvc spec.
+func DropDisabledAlphaFields(pvcSpec *core.PersistentVolumeClaimSpec) {
+	if !utilfeature.DefaultFeatureGate.Enabled(features.BlockVolume) {
+		pvcSpec.VolumeMode = nil
+	}
+}

pkg/api/persistentvolumeclaim/util_test.go

+/*
+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 persistentvolumeclaim
+
+import (
+	"testing"
+
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
+	"k8s.io/kubernetes/pkg/apis/core"
+	"k8s.io/kubernetes/pkg/features"
+)
+
+func TestDropAlphaPVCVolumeMode(t *testing.T) {
+	vmode := core.PersistentVolumeFilesystem
+
+	// PersistentVolume with VolumeMode set
+	pvc := core.PersistentVolumeClaim{
+		Spec: core.PersistentVolumeClaimSpec{
+			AccessModes: []core.PersistentVolumeAccessMode{core.ReadWriteOnce},
+			VolumeMode:  &vmode,
+		},
+	}
+
+	// Enable alpha feature BlockVolume
+	err1 := utilfeature.DefaultFeatureGate.Set("BlockVolume=true")
+	if err1 != nil {
+		t.Fatalf("Failed to enable feature gate for BlockVolume: %v", err1)
+	}
+
+	// now test dropping the fields - should not be dropped
+	DropDisabledAlphaFields(&pvc.Spec)
+
+	// check to make sure VolumeDevices is still present
+	// if featureset is set to true
+	if utilfeature.DefaultFeatureGate.Enabled(features.BlockVolume) {
+		if pvc.Spec.VolumeMode == nil {
+			t.Error("VolumeMode in pvc.Spec should not have been dropped based on feature-gate")
+		}
+	}
+
+	// Disable alpha feature BlockVolume
+	err := utilfeature.DefaultFeatureGate.Set("BlockVolume=false")
+	if err != nil {
+		t.Fatalf("Failed to disable feature gate for BlockVolume: %v", err)
+	}
+
+	// now test dropping the fields
+	DropDisabledAlphaFields(&pvc.Spec)
+
+	// check to make sure VolumeDevices is nil
+	// if featureset is set to false
+	if !utilfeature.DefaultFeatureGate.Enabled(features.BlockVolume) {
+		if pvc.Spec.VolumeMode != nil {
+			t.Error("DropDisabledAlphaFields VolumeMode for pvc.Spec failed")
+		}
+	}
+}

pkg/api/pod/util.go

@@ -243,12 +243,15 @@ func DropDisabledAlphaFields(podSpec *api.PodSpec) {
 			}
 		}
 	}
+
 	for i := range podSpec.Containers {
 		DropDisabledVolumeMountsAlphaFields(podSpec.Containers[i].VolumeMounts)
 	}
 	for i := range podSpec.InitContainers {
 		DropDisabledVolumeMountsAlphaFields(podSpec.InitContainers[i].VolumeMounts)
 	}
+
+	DropDisabledVolumeDevicesAlphaFields(podSpec)
 }
 
 // DropDisabledVolumeMountsAlphaFields removes disabled fields from []VolumeMount.
@@ -260,3 +263,16 @@ func DropDisabledVolumeMountsAlphaFields(volumeMounts []api.VolumeMount) {
 		}
 	}
 }
+
+// DropDisabledVolumeDevicesAlphaFields removes disabled fields from []VolumeDevice.
+// This should be called from PrepareForCreate/PrepareForUpdate for all resources containing a VolumeDevice
+func DropDisabledVolumeDevicesAlphaFields(podSpec *api.PodSpec) {
+	if !utilfeature.DefaultFeatureGate.Enabled(features.BlockVolume) {
+		for i := range podSpec.Containers {
+			podSpec.Containers[i].VolumeDevices = nil
+		}
+		for i := range podSpec.InitContainers {
+			podSpec.InitContainers[i].VolumeDevices = nil
+		}
+	}
+}

pkg/api/pod/util_test.go

@@ -24,7 +24,9 @@ import (
 
 	"k8s.io/apimachinery/pkg/util/sets"
 	"k8s.io/apimachinery/pkg/util/validation/field"
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	api "k8s.io/kubernetes/pkg/apis/core"
+	"k8s.io/kubernetes/pkg/features"
 )
 
 func TestPodSecrets(t *testing.T) {
@@ -254,3 +256,85 @@ func TestPodConfigmaps(t *testing.T) {
 		t.Error("Extra names extracted. Verify VisitPodConfigmapNames() is correctly extracting resource names")
 	}
 }
+
+func TestDropAlphaVolumeDevices(t *testing.T) {
+	testPod := api.Pod{
+		Spec: api.PodSpec{
+			RestartPolicy: api.RestartPolicyNever,
+			Containers: []api.Container{
+				{
+					Name:  "container1",
+					Image: "testimage",
+					VolumeDevices: []api.VolumeDevice{
+						{
+							Name:       "myvolume",
+							DevicePath: "/usr/test",
+						},
+					},
+				},
+			},
+			InitContainers: []api.Container{
+				{
+					Name:  "container1",
+					Image: "testimage",
+					VolumeDevices: []api.VolumeDevice{
+						{
+							Name:       "myvolume",
+							DevicePath: "/usr/test",
+						},
+					},
+				},
+			},
+			Volumes: []api.Volume{
+				{
+					Name: "myvolume",
+					VolumeSource: api.VolumeSource{
+						HostPath: &api.HostPathVolumeSource{
+							Path: "/dev/xvdc",
+						},
+					},
+				},
+			},
+		},
+	}
+
+	// Enable alpha feature BlockVolume
+	err1 := utilfeature.DefaultFeatureGate.Set("BlockVolume=true")
+	if err1 != nil {
+		t.Fatalf("Failed to enable feature gate for BlockVolume: %v", err1)
+	}
+
+	// now test dropping the fields - should not be dropped
+	DropDisabledAlphaFields(&testPod.Spec)
+
+	// check to make sure VolumeDevices is still present
+	// if featureset is set to true
+	if utilfeature.DefaultFeatureGate.Enabled(features.BlockVolume) {
+		if testPod.Spec.Containers[0].VolumeDevices == nil {
+			t.Error("VolumeDevices in Container should not have been dropped based on feature-gate")
+		}
+		if testPod.Spec.InitContainers[0].VolumeDevices == nil {
+			t.Error("VolumeDevices in Container should not have been dropped based on feature-gate")
+		}
+	}
+
+	// Disable alpha feature BlockVolume
+	err := utilfeature.DefaultFeatureGate.Set("BlockVolume=false")
+	if err != nil {
+		t.Fatalf("Failed to disable feature gate for BlockVolume: %v", err)
+	}
+
+	// now test dropping the fields
+	DropDisabledAlphaFields(&testPod.Spec)
+
+	// check to make sure VolumeDevices is nil
+	// if featureset is set to false
+	if !utilfeature.DefaultFeatureGate.Enabled(features.BlockVolume) {
+		if testPod.Spec.Containers[0].VolumeDevices != nil {
+			t.Error("DropDisabledAlphaFields for Containers failed")
+		}
+		if testPod.Spec.InitContainers[0].VolumeDevices != nil {
+			t.Error("DropDisabledAlphaFields for InitContainers failed")
+		}
+	}
+}

pkg/apis/core/types.go

@@ -462,6 +462,11 @@ type PersistentVolumeSpec struct {
 	// simply fail if one is invalid.
 	// +optional
 	MountOptions []string
+	// volumeMode defines if a volume is intended to be used with a formatted filesystem
+	// or to remain in raw block state. Value of Filesystem is implied when not included in spec.
+	// This is an alpha feature and may change in the future.
+	// +optional
+	VolumeMode *PersistentVolumeMode
 }
 
 // PersistentVolumeReclaimPolicy describes a policy for end-of-life maintenance of persistent volumes
@@ -479,6 +484,16 @@ const (
 	PersistentVolumeReclaimRetain PersistentVolumeReclaimPolicy = "Retain"
 )
 
+// PersistentVolumeMode describes how a volume is intended to be consumed, either Block or Filesystem.
+type PersistentVolumeMode string
+
+const (
+	// PersistentVolumeBlock means the volume will not be formatted with a filesystem and will remain a raw block device.
+	PersistentVolumeBlock PersistentVolumeMode = "Block"
+	// PersistentVolumeFilesystem means the volume will be or is formatted with a filesystem.
+	PersistentVolumeFilesystem PersistentVolumeMode = "Filesystem"
+)
+
 type PersistentVolumeStatus struct {
 	// Phase indicates if a volume is available, bound to a claim, or released by a claim
 	// +optional
@@ -548,6 +563,11 @@ type PersistentVolumeClaimSpec struct {
 	// More info: https://kubernetes.io/docs/concepts/storage/persistent-volumes/#class-1
 	// +optional
 	StorageClassName *string
+	// volumeMode defines what type of volume is required by the claim.
+	// Value of Filesystem is implied when not included in claim spec.
+	// This is an alpha feature and may change in the future.
+	// +optional
+	VolumeMode *PersistentVolumeMode
 }
 
 type PersistentVolumeClaimConditionType string
@@ -1586,6 +1606,14 @@ const (
 	MountPropagationBidirectional MountPropagationMode = "Bidirectional"
 )
 
+// VolumeDevice describes a mapping of a raw block device within a container.
+type VolumeDevice struct {
+	// name must match the name of a persistentVolumeClaim in the pod
+	Name string
+	// devicePath is the path inside of the container that the device will be mapped to.
+	DevicePath string
+}
+
 // EnvVar represents an environment variable present in a Container.
 type EnvVar struct {
 	// Required: This must be a C_IDENTIFIER.
@@ -1879,6 +1907,10 @@ type Container struct {
 	Resources ResourceRequirements
 	// +optional
 	VolumeMounts []VolumeMount
+	// volumeDevices is the list of block devices to be used by the container.
+	// This is an alpha feature and may change in the future.
+	// +optional
+	VolumeDevices []VolumeDevice
 	// +optional
 	LivenessProbe *Probe
 	// +optional

pkg/apis/core/v1/defaults.go

@@ -20,6 +20,8 @@ import (
 	"k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/util/intstr"
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
+	"k8s.io/kubernetes/pkg/features"
 	"k8s.io/kubernetes/pkg/util/parsers"
 	utilpointer "k8s.io/kubernetes/pkg/util/pointer"
 )
@@ -228,11 +230,19 @@ func SetDefaults_PersistentVolume(obj *v1.PersistentVolume) {
 	if obj.Spec.PersistentVolumeReclaimPolicy == "" {
 		obj.Spec.PersistentVolumeReclaimPolicy = v1.PersistentVolumeReclaimRetain
 	}
+	if obj.Spec.VolumeMode == nil && utilfeature.DefaultFeatureGate.Enabled(features.BlockVolume) {
+		obj.Spec.VolumeMode = new(v1.PersistentVolumeMode)
+		*obj.Spec.VolumeMode = v1.PersistentVolumeFilesystem
+	}
 }
 func SetDefaults_PersistentVolumeClaim(obj *v1.PersistentVolumeClaim) {
 	if obj.Status.Phase == "" {
 		obj.Status.Phase = v1.ClaimPending
 	}
+	if obj.Spec.VolumeMode == nil && utilfeature.DefaultFeatureGate.Enabled(features.BlockVolume) {
+		obj.Spec.VolumeMode = new(v1.PersistentVolumeMode)
+		*obj.Spec.VolumeMode = v1.PersistentVolumeFilesystem
+	}
 }
 func SetDefaults_ISCSIVolumeSource(obj *v1.ISCSIVolumeSource) {
 	if obj.ISCSIInterface == "" {

pkg/apis/core/v1/defaults_test.go

@@ -26,6 +26,7 @@ import (
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/util/intstr"
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	"k8s.io/kubernetes/pkg/api/legacyscheme"
 	corev1 "k8s.io/kubernetes/pkg/apis/core/v1"
 
@@ -817,6 +818,33 @@ func TestSetDefaultPersistentVolume(t *testing.T) {
 	if pv2.Spec.PersistentVolumeReclaimPolicy != v1.PersistentVolumeReclaimRetain {
 		t.Errorf("Expected pv reclaim policy %v, got %v", v1.PersistentVolumeReclaimRetain, pv2.Spec.PersistentVolumeReclaimPolicy)
 	}
+
+	// When feature gate is disabled, field should not be defaulted
+	defaultMode := v1.PersistentVolumeFilesystem
+	outputMode := pv2.Spec.VolumeMode
+	if outputMode != nil {
+		t.Errorf("Expected VolumeMode to not be defaulted, got: %+v", outputMode)
+	}
+
+	// When feature gate is enabled, field should be defaulted
+	err := utilfeature.DefaultFeatureGate.Set("BlockVolume=true")
+	if err != nil {
+		t.Fatalf("Failed to enable feature gate for BlockVolume: %v", err)
+	}
+	obj3 := roundTrip(t, runtime.Object(pv)).(*v1.PersistentVolume)
+	outputMode3 := obj3.Spec.VolumeMode
+
+	if outputMode3 == nil {
+		t.Errorf("Expected VolumeMode to be defaulted to: %+v, got: nil", defaultMode)
+	} else if *outputMode3 != defaultMode {
+		t.Errorf("Expected VolumeMode to be defaulted to: %+v, got: %+v", defaultMode, outputMode3)
+	}
+
+	err = utilfeature.DefaultFeatureGate.Set("BlockVolume=false")
+	if err != nil {
+		t.Fatalf("Failed to disable feature gate for BlockVolume: %v", err)
+	}
+
 }
 
 func TestSetDefaultPersistentVolumeClaim(t *testing.T) {
@@ -827,6 +855,32 @@ func TestSetDefaultPersistentVolumeClaim(t *testing.T) {
 	if pvc2.Status.Phase != v1.ClaimPending {
 		t.Errorf("Expected claim phase %v, got %v", v1.ClaimPending, pvc2.Status.Phase)
 	}
+
+	// When feature gate is disabled, field should not be defaulted
+	defaultMode := v1.PersistentVolumeFilesystem
+	outputMode := pvc2.Spec.VolumeMode
+	if outputMode != nil {
+		t.Errorf("Expected VolumeMode to not be defaulted, got: %+v", outputMode)
+	}
+
+	// When feature gate is enabled, field should be defaulted
+	err := utilfeature.DefaultFeatureGate.Set("BlockVolume=true")
+	if err != nil {
+		t.Fatalf("Failed to enable feature gate for BlockVolume: %v", err)
+	}
+	obj3 := roundTrip(t, runtime.Object(pvc)).(*v1.PersistentVolumeClaim)
+	outputMode3 := obj3.Spec.VolumeMode
+
+	if outputMode3 == nil {
+		t.Errorf("Expected VolumeMode to be defaulted to: %+v, got: nil", defaultMode)
+	} else if *outputMode3 != defaultMode {
+		t.Errorf("Expected VolumeMode to be defaulted to: %+v, got: %+v", defaultMode, outputMode3)
+	}
+
+	err = utilfeature.DefaultFeatureGate.Set("BlockVolume=false")
+	if err != nil {
+		t.Fatalf("Failed to disable feature gate for BlockVolume: %v", err)
+	}
 }
 
 func TestSetDefaulEndpointsProtocol(t *testing.T) {

pkg/apis/settings/validation/validation.go

@@ -43,11 +43,11 @@ func ValidatePodPresetSpec(spec *settings.PodPresetSpec, fldPath *field.Path) fi
 		allErrs = append(allErrs, field.Required(fldPath.Child("volumes", "env", "envFrom", "volumeMounts"), "must specify at least one"))
 	}
 
-	volumes, vErrs := apivalidation.ValidateVolumes(spec.Volumes, fldPath.Child("volumes"))
+	vols, vErrs := apivalidation.ValidateVolumes(spec.Volumes, fldPath.Child("volumes"))
 	allErrs = append(allErrs, vErrs...)
 	allErrs = append(allErrs, apivalidation.ValidateEnv(spec.Env, fldPath.Child("env"))...)
 	allErrs = append(allErrs, apivalidation.ValidateEnvFrom(spec.EnvFrom, fldPath.Child("envFrom"))...)
-	allErrs = append(allErrs, apivalidation.ValidateVolumeMounts(spec.VolumeMounts, volumes, nil, fldPath.Child("volumeMounts"))...)
+	allErrs = append(allErrs, apivalidation.ValidateVolumeMounts(spec.VolumeMounts, nil, vols, nil, fldPath.Child("volumeMounts"))...)
 
 	return allErrs
 }

pkg/features/kube_features.go

@@ -187,6 +187,12 @@ const (
 	//
 	// Enable mount/attachment of Container Storage Interface (CSI) backed PVs
 	CSIPersistentVolume utilfeature.Feature = "CSIPersistentVolume"
+
+	// owner: @screeley44
+	// alpha: v1.9
+	//
+	// Enable Block volume support in containers.
+	BlockVolume utilfeature.Feature = "BlockVolume"
 )
 
 func init() {
@@ -222,6 +228,7 @@ var defaultKubernetesFeatureGates = map[utilfeature.Feature]utilfeature.FeatureS
 	MountContainers:                             {Default: false, PreRelease: utilfeature.Alpha},
 	VolumeScheduling:                            {Default: false, PreRelease: utilfeature.Alpha},
 	CSIPersistentVolume:                         {Default: false, PreRelease: utilfeature.Alpha},
+	BlockVolume:                                 {Default: false, PreRelease: utilfeature.Alpha},
 
 	// inherited features from generic apiserver, relisted here to get a conflict if it is changed
 	// unintentionally on either side:

pkg/registry/core/persistentvolume/strategy.go

@@ -28,6 +28,7 @@ import (
 	"k8s.io/apiserver/pkg/storage"
 	"k8s.io/apiserver/pkg/storage/names"
 	"k8s.io/kubernetes/pkg/api/legacyscheme"
+	pvutil "k8s.io/kubernetes/pkg/api/persistentvolume"
 	api "k8s.io/kubernetes/pkg/apis/core"
 	"k8s.io/kubernetes/pkg/apis/core/validation"
 	volumevalidation "k8s.io/kubernetes/pkg/volume/validation"
@@ -51,6 +52,8 @@ func (persistentvolumeStrategy) NamespaceScoped() bool {
 func (persistentvolumeStrategy) PrepareForCreate(ctx genericapirequest.Context, obj runtime.Object) {
 	pv := obj.(*api.PersistentVolume)
 	pv.Status = api.PersistentVolumeStatus{}
+
+	pvutil.DropDisabledAlphaFields(&pv.Spec)
 }
 
 func (persistentvolumeStrategy) Validate(ctx genericapirequest.Context, obj runtime.Object) field.ErrorList {
@@ -72,6 +75,9 @@ func (persistentvolumeStrategy) PrepareForUpdate(ctx genericapirequest.Context,
 	newPv := obj.(*api.PersistentVolume)
 	oldPv := old.(*api.PersistentVolume)
 	newPv.Status = oldPv.Status
+
+	pvutil.DropDisabledAlphaFields(&newPv.Spec)
+	pvutil.DropDisabledAlphaFields(&oldPv.Spec)
 }
 
 func (persistentvolumeStrategy) ValidateUpdate(ctx genericapirequest.Context, obj, old runtime.Object) field.ErrorList {

pkg/registry/core/persistentvolumeclaim/strategy.go

@@ -28,6 +28,7 @@ import (
 	"k8s.io/apiserver/pkg/storage"
 	"k8s.io/apiserver/pkg/storage/names"
 	"k8s.io/kubernetes/pkg/api/legacyscheme"
+	pvcutil "k8s.io/kubernetes/pkg/api/persistentvolumeclaim"
 	api "k8s.io/kubernetes/pkg/apis/core"
 	"k8s.io/kubernetes/pkg/apis/core/validation"
 )
@@ -48,8 +49,10 @@ func (persistentvolumeclaimStrategy) NamespaceScoped() bool {
 
 // PrepareForCreate clears the Status field which is not allowed to be set by end users on creation.
 func (persistentvolumeclaimStrategy) PrepareForCreate(ctx genericapirequest.Context, obj runtime.Object) {
-	pv := obj.(*api.PersistentVolumeClaim)
-	pv.Status = api.PersistentVolumeClaimStatus{}
+	pvc := obj.(*api.PersistentVolumeClaim)
+	pvc.Status = api.PersistentVolumeClaimStatus{}
+
+	pvcutil.DropDisabledAlphaFields(&pvc.Spec)
 }
 
 func (persistentvolumeclaimStrategy) Validate(ctx genericapirequest.Context, obj runtime.Object) field.ErrorList {
@@ -70,6 +73,9 @@ func (persistentvolumeclaimStrategy) PrepareForUpdate(ctx genericapirequest.Cont
 	newPvc := obj.(*api.PersistentVolumeClaim)
 	oldPvc := old.(*api.PersistentVolumeClaim)
 	newPvc.Status = oldPvc.Status
+
+	pvcutil.DropDisabledAlphaFields(&newPvc.Spec)
+	pvcutil.DropDisabledAlphaFields(&oldPvc.Spec)
 }
 
 func (persistentvolumeclaimStrategy) ValidateUpdate(ctx genericapirequest.Context, obj, old runtime.Object) field.ErrorList {

staging/src/k8s.io/api/core/v1/types.go

@@ -527,6 +527,11 @@ type PersistentVolumeSpec struct {
 	// More info: https://kubernetes.io/docs/concepts/storage/persistent-volumes/#mount-options
 	// +optional
 	MountOptions []string `json:"mountOptions,omitempty" protobuf:"bytes,7,opt,name=mountOptions"`
+	// volumeMode defines if a volume is intended to be used with a formatted filesystem
+	// or to remain in raw block state. Value of Filesystem is implied when not included in spec.
+	// This is an alpha feature and may change in the future.
+	// +optional
+	VolumeMode *PersistentVolumeMode `json:"volumeMode,omitempty" protobuf:"bytes,8,opt,name=volumeMode,casttype=PersistentVolumeMode"`
 }
 
 // PersistentVolumeReclaimPolicy describes a policy for end-of-life maintenance of persistent volumes.
@@ -544,6 +549,16 @@ const (
 	PersistentVolumeReclaimRetain PersistentVolumeReclaimPolicy = "Retain"
 )
 
+// PersistentVolumeMode describes how a volume is intended to be consumed, either Block or Filesystem.
+type PersistentVolumeMode string
+
+const (
+	// PersistentVolumeBlock means the volume will not be formatted with a filesystem and will remain a raw block device.
+	PersistentVolumeBlock PersistentVolumeMode = "Block"
+	// PersistentVolumeFilesystem means the volume will be or is formatted with a filesystem.
+	PersistentVolumeFilesystem PersistentVolumeMode = "Filesystem"
+)
+
 // PersistentVolumeStatus is the current status of a persistent volume.
 type PersistentVolumeStatus struct {
 	// Phase indicates if a volume is available, bound to a claim, or released by a claim.
@@ -631,6 +646,11 @@ type PersistentVolumeClaimSpec struct {
 	// More info: https://kubernetes.io/docs/concepts/storage/persistent-volumes#class-1
 	// +optional
 	StorageClassName *string `json:"storageClassName,omitempty" protobuf:"bytes,5,opt,name=storageClassName"`
+	// volumeMode defines what type of volume is required by the claim.
+	// Value of Filesystem is implied when not included in claim spec.
+	// This is an alpha feature and may change in the future.
+	// +optional
+	VolumeMode *PersistentVolumeMode `json:"volumeMode,omitempty" protobuf:"bytes,6,opt,name=volumeMode,casttype=PersistentVolumeMode"`
 }
 
 // PersistentVolumeClaimConditionType is a valid value of PersistentVolumeClaimCondition.Type
@@ -1709,6 +1729,14 @@ const (
 	MountPropagationBidirectional MountPropagationMode = "Bidirectional"
 )
 
+// volumeDevice describes a mapping of a raw block device within a container.
+type VolumeDevice struct {
+	// name must match the name of a persistentVolumeClaim in the pod
+	Name string `json:"name" protobuf:"bytes,1,opt,name=name"`
+	// devicePath is the path inside of the container that the device will be mapped to.
+	DevicePath string `json:"devicePath" protobuf:"bytes,2,opt,name=devicePath"`
+}
+
 // EnvVar represents an environment variable present in a Container.
 type EnvVar struct {
 	// Name of the environment variable. Must be a C_IDENTIFIER.
@@ -2052,6 +2080,12 @@ type Container struct {
 	// +patchMergeKey=mountPath
 	// +patchStrategy=merge
 	VolumeMounts []VolumeMount `json:"volumeMounts,omitempty" patchStrategy:"merge" patchMergeKey:"mountPath" protobuf:"bytes,9,rep,name=volumeMounts"`
+	// volumeDevices is the list of block devices to be used by the container.
+	// This is an alpha feature and may change in the future.
+	// +patchMergeKey=devicePath
+	// +patchStrategy=merge
+	// +optional
+	VolumeDevices []VolumeDevice `json:"volumeDevices,omitempty" patchStrategy:"merge" patchMergeKey:"devicePath" protobuf:"bytes,21,rep,name=volumeDevices"`
 	// Periodic probe of container liveness.
 	// Container will be restarted if the probe fails.
 	// Cannot be updated.