Add validation for feature gate

pkg/apis/core/validation/validation.go

@@ -1824,6 +1824,22 @@ func ValidatePersistentVolumeClaimSpec(spec *core.PersistentVolumeClaimSpec, fld
 	} else if spec.VolumeMode != nil && !supportedVolumeModes.Has(string(*spec.VolumeMode)) {
 		allErrs = append(allErrs, field.NotSupported(fldPath.Child("volumeMode"), *spec.VolumeMode, supportedVolumeModes.List()))
 	}
+
+	if spec.DataSource != nil && !utilfeature.DefaultFeatureGate.Enabled(features.VolumeSnapshotDataSource) {
+		allErrs = append(allErrs, field.Forbidden(fldPath.Child("dataSource"), "VolumeSnapshotDataSource is disabled by feature-gate"))
+		spec.DataSource = nil
+	} else if spec.DataSource != nil {
+		if len(spec.DataSource.Name) == 0 {
+			allErrs = append(allErrs, field.Required(fldPath.Child("dataSource").Key(string("Name")), "VolumeSnapshotDataSource Name cannot be empty"))
+		}
+		if spec.DataSource.Kind != "VolumeSnapshot" {
+			allErrs = append(allErrs, field.Invalid(fldPath.Child("dataSource"), spec.DataSource.Kind, "expected DataSource Kind is VolumeSnapshot"))
+		}
+		if spec.DataSource.APIGroup != "snapshot.storage.k8s.io" {
+			allErrs = append(allErrs, field.Invalid(fldPath.Child("dataSource"), spec.DataSource.APIGroup, "expected DataSource APIGroup is snapshot.storage.k8s.io"))
+		}
+	}
+
 	return allErrs
 }
 

pkg/apis/core/validation/validation_test.go

@@ -713,6 +713,67 @@ func testVolumeClaimStorageClassInSpec(name, namespace, scName string, spec core
 	}
 }
 
+func testVolumeSnapshotDataSourceInSpec(name string, kind string, apiGroup string) *core.PersistentVolumeClaimSpec {
+	scName := "csi-plugin"
+	dataSourceInSpec := core.PersistentVolumeClaimSpec{
+		AccessModes: []core.PersistentVolumeAccessMode{
+			core.ReadOnlyMany,
+		},
+		Resources: core.ResourceRequirements{
+			Requests: core.ResourceList{
+				core.ResourceName(core.ResourceStorage): resource.MustParse("10G"),
+			},
+		},
+		StorageClassName: &scName,
+		DataSource: &core.TypedLocalObjectReference{
+			APIGroup: apiGroup,
+			Kind:     kind,
+			Name:     name,
+		},
+	}
+
+	return &dataSourceInSpec
+}
+
+func TestAlphaVolumeSnapshotDataSource(t *testing.T) {
+	successTestCases := []core.PersistentVolumeClaimSpec{
+		*testVolumeSnapshotDataSourceInSpec("test_snapshot", "VolumeSnapshot", "snapshot.storage.k8s.io"),
+	}
+	failedTestCases := []core.PersistentVolumeClaimSpec{
+		*testVolumeSnapshotDataSourceInSpec("", "VolumeSnapshot", "snapshot.storage.k8s.io"),
+		*testVolumeSnapshotDataSourceInSpec("test_snapshot", "PersistentVolumeClaim", "snapshot.storage.k8s.io"),
+		*testVolumeSnapshotDataSourceInSpec("test_snapshot", "VolumeSnapshot", "storage.k8s.io"),
+	}
+
+	// Enable alpha feature VolumeSnapshotDataSource
+	err := utilfeature.DefaultFeatureGate.Set("VolumeSnapshotDataSource=true")
+	if err != nil {
+		t.Errorf("Failed to enable feature gate for VolumeSnapshotDataSource: %v", err)
+		return
+	}
+	for _, tc := range successTestCases {
+		if errs := ValidatePersistentVolumeClaimSpec(&tc, field.NewPath("spec")); len(errs) != 0 {
+			t.Errorf("expected success: %v", errs)
+		}
+	}
+	for _, tc := range failedTestCases {
+		if errs := ValidatePersistentVolumeClaimSpec(&tc, field.NewPath("spec")); len(errs) == 0 {
+			t.Errorf("expected failure: %v", errs)
+		}
+	}
+	// Disable alpha feature VolumeSnapshotDataSource
+	err = utilfeature.DefaultFeatureGate.Set("VolumeSnapshotDataSource=false")
+	if err != nil {
+		t.Errorf("Failed to disable feature gate for VolumeSnapshotDataSource: %v", err)
+		return
+	}
+	for _, tc := range successTestCases {
+		if errs := ValidatePersistentVolumeClaimSpec(&tc, field.NewPath("spec")); len(errs) == 0 {
+			t.Errorf("expected failure: %v", errs)
+		}
+	}
+}
+
 func testVolumeClaimStorageClassInAnnotationAndSpec(name, namespace, scNameInAnn, scName string, spec core.PersistentVolumeClaimSpec) *core.PersistentVolumeClaim {
 	spec.StorageClassName = &scName
 	return &core.PersistentVolumeClaim{