VolumeMode binding logic update

pkg/controller/volume/persistentvolume/BUILD

@@ -20,6 +20,7 @@ go_library(
         "//pkg/cloudprovider:go_default_library",
         "//pkg/controller:go_default_library",
         "//pkg/controller/volume/events:go_default_library",
+        "//pkg/features:go_default_library",
         "//pkg/util/goroutinemap:go_default_library",
         "//pkg/util/goroutinemap/exponentialbackoff:go_default_library",
         "//pkg/util/io:go_default_library",
@@ -37,6 +38,7 @@ go_library(
         "//vendor/k8s.io/apimachinery/pkg/types:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/util/runtime:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/util/wait:go_default_library",
+        "//vendor/k8s.io/apiserver/pkg/util/feature:go_default_library",
         "//vendor/k8s.io/client-go/informers/core/v1:go_default_library",
         "//vendor/k8s.io/client-go/informers/storage/v1:go_default_library",
         "//vendor/k8s.io/client-go/kubernetes:go_default_library",
@@ -80,6 +82,7 @@ go_test(
         "//vendor/k8s.io/apimachinery/pkg/util/diff:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/util/wait:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/watch:go_default_library",
+        "//vendor/k8s.io/apiserver/pkg/util/feature:go_default_library",
         "//vendor/k8s.io/client-go/informers:go_default_library",
         "//vendor/k8s.io/client-go/kubernetes:go_default_library",
         "//vendor/k8s.io/client-go/kubernetes/fake:go_default_library",

pkg/controller/volume/persistentvolume/framework_test.go

@@ -680,6 +680,22 @@ func withLabelSelector(labels map[string]string, claims []*v1.PersistentVolumeCl
 	return claims
 }
 
+// withVolumeVolumeMode applies the given VolumeMode to the first volume in the array and
+// returns the array.  Meant to be used to compose volumes specified inline in
+// a test.
+func withVolumeVolumeMode(mode *v1.PersistentVolumeMode, volumes []*v1.PersistentVolume) []*v1.PersistentVolume {
+	volumes[0].Spec.VolumeMode = mode
+	return volumes
+}
+
+// withClaimVolumeMode applies the given VolumeMode to the first claim in the array and
+// returns the array.  Meant to be used to compose volumes specified inline in
+// a test.
+func withClaimVolumeMode(mode *v1.PersistentVolumeMode, claims []*v1.PersistentVolumeClaim) []*v1.PersistentVolumeClaim {
+	claims[0].Spec.VolumeMode = mode
+	return claims
+}
+
 // withExpectedCapacity sets the claim.Spec.Capacity of the first claim in the
 // array to given value and returns the array.  Meant to be used to compose
 // claims specified inline in a test.

pkg/controller/volume/persistentvolume/index.go

@@ -24,8 +24,10 @@ import (
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/labels"
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	"k8s.io/client-go/tools/cache"
 	v1helper "k8s.io/kubernetes/pkg/apis/core/v1/helper"
+	"k8s.io/kubernetes/pkg/features"
 	"k8s.io/kubernetes/pkg/volume"
 )
 
@@ -116,6 +118,16 @@ func (pvIndex *persistentVolumeOrderedIndex) findByClaim(claim *v1.PersistentVol
 		// - find the smallest matching one if there is no volume pre-bound to
 		//   the claim.
 		for _, volume := range volumes {
+			// check if volumeModes do not match (Alpha and feature gate protected)
+			isMisMatch, err := checkVolumeModeMisMatches(&claim.Spec, &volume.Spec)
+			if err != nil {
+				return nil, fmt.Errorf("error checking if volumeMode was a mismatch: %v", err)
+			}
+			// filter out mismatching volumeModes
+			if isMisMatch {
+				continue
+			}
+
 			if isVolumeBoundToClaim(volume, claim) {
 				// this claim and volume are pre-bound; return
 				// the volume if the size request is satisfied,
@@ -157,6 +169,27 @@ func (pvIndex *persistentVolumeOrderedIndex) findByClaim(claim *v1.PersistentVol
 	return nil, nil
 }
 
+// checkVolumeModeMatches is a convenience method that checks volumeMode for PersistentVolume
+// and PersistentVolumeClaims along with making sure that the Alpha feature gate BlockVolume is
+// enabled.
+// This is Alpha and could change in the future.
+func checkVolumeModeMisMatches(pvcSpec *v1.PersistentVolumeClaimSpec, pvSpec *v1.PersistentVolumeSpec) (bool, error) {
+	if utilfeature.DefaultFeatureGate.Enabled(features.BlockVolume) {
+		if pvSpec.VolumeMode != nil && pvcSpec.VolumeMode != nil {
+			requestedVolumeMode := *pvcSpec.VolumeMode
+			pvVolumeMode := *pvSpec.VolumeMode
+			return requestedVolumeMode != pvVolumeMode, nil
+		} else {
+			// This also should retrun an error, this means that
+			// the defaulting has failed.
+			return true, fmt.Errorf("api defaulting for volumeMode failed")
+		}
+	} else {
+		// feature gate is disabled
+		return false, nil
+	}
+}
+
 // findBestMatchForClaim is a convenience method that finds a volume by the claim's AccessModes and requests for Storage
 func (pvIndex *persistentVolumeOrderedIndex) findBestMatchForClaim(claim *v1.PersistentVolumeClaim) (*v1.PersistentVolume, error) {
 	return pvIndex.findByClaim(claim)

pkg/controller/volume/persistentvolume/pv_controller.go

@@ -231,6 +231,10 @@ func (ctrl *PersistentVolumeController) syncClaim(claim *v1.PersistentVolumeClai
 func checkVolumeSatisfyClaim(volume *v1.PersistentVolume, claim *v1.PersistentVolumeClaim) error {
 	requestedQty := claim.Spec.Resources.Requests[v1.ResourceName(v1.ResourceStorage)]
 	requestedSize := requestedQty.Value()
+	isMisMatch, err := checkVolumeModeMisMatches(&claim.Spec, &volume.Spec)
+	if err != nil {
+		return fmt.Errorf("error checking if volumeMode was a mismatch: %v", err)
+	}
 
 	volumeQty := volume.Spec.Capacity[v1.ResourceStorage]
 	volumeSize := volumeQty.Value()
@@ -243,6 +247,10 @@ func checkVolumeSatisfyClaim(volume *v1.PersistentVolume, claim *v1.PersistentVo
 		return fmt.Errorf("Class of volume[%s] is not the same as claim[%v]", volume.Name, claimToClaimKey(claim))
 	}
 
+	if isMisMatch {
+		return fmt.Errorf("VolumeMode[%v] of volume[%s] is incompatible with VolumeMode[%v] of claim[%v]", volume.Spec.VolumeMode, volume.Name, claim.Spec.VolumeMode, claim.Name)
+	}
+
 	return nil
 }