set default HostPathType to empty

pkg/api/fuzzer/fuzzer.go

@@ -357,8 +357,8 @@ var Funcs = func(codecs runtimeserializer.CodecFactory) []interface{} {
 		},
 		func(obj *api.HostPathVolumeSource, c fuzz.Continue) {
 			c.FuzzNoCustom(obj)
-			types := []api.HostPathType{api.HostPathDirectoryOrCreate, api.HostPathDirectory, api.HostPathFileOrCreate,
+			types := []api.HostPathType{api.HostPathUnset, api.HostPathDirectoryOrCreate, api.HostPathDirectory,
-				api.HostPathFile, api.HostPathSocket, api.HostPathCharDev, api.HostPathBlockDev}
+				api.HostPathFileOrCreate, api.HostPathFile, api.HostPathSocket, api.HostPathCharDev, api.HostPathBlockDev}
 			typeVol := types[c.Rand.Intn(len(types))]
 			if obj.Path != "" && obj.Type == nil {
 				obj.Type = &typeVol

pkg/api/types.go

@@ -600,6 +600,8 @@ const (
 type HostPathType string
 
 const (
+	// For backwards compatible, leave it empty if unset
+	HostPathUnset HostPathType = ""
 	// If nothing exists at the given path, an empty directory will be created there
 	// as needed with file mode 0755, having the same group and ownership with Kubelet.
 	HostPathDirectoryOrCreate HostPathType = "DirectoryOrCreate"
@@ -623,7 +625,7 @@ const (
 type HostPathVolumeSource struct {
 	// If the path is a symlink, it will follow the link to the real path.
 	Path string
-	// Defaults to DirectoryOrCreate
+	// Defaults to ""
 	Type *HostPathType
 }
 

pkg/api/v1/defaults.go

@@ -371,7 +371,7 @@ func SetDefaults_ScaleIOVolumeSource(obj *v1.ScaleIOVolumeSource) {
 }
 
 func SetDefaults_HostPathVolumeSource(obj *v1.HostPathVolumeSource) {
-	typeVol := v1.HostPathDirectoryOrCreate
+	typeVol := v1.HostPathUnset
 	if obj.Type == nil {
 		obj.Type = &typeVol
 	}

pkg/api/v1/defaults_test.go

@@ -1277,3 +1277,25 @@ func TestSetDefaultSchedulerName(t *testing.T) {
 		t.Errorf("Expected scheduler name: %+v\ngot: %+v\n", v1.DefaultSchedulerName, output.Spec.SchedulerName)
 	}
 }
+
+func TestSetDefaultHostPathVolumeSource(t *testing.T) {
+	s := v1.PodSpec{}
+	s.Volumes = []v1.Volume{
+		{
+			VolumeSource: v1.VolumeSource{
+				HostPath: &v1.HostPathVolumeSource{Path: "foo"},
+			},
+		},
+	}
+	pod := &v1.Pod{
+		Spec: s,
+	}
+	output := roundTrip(t, runtime.Object(pod))
+	pod2 := output.(*v1.Pod)
+	defaultType := pod2.Spec.Volumes[0].VolumeSource.HostPath.Type
+	expectedType := v1.HostPathUnset
+
+	if defaultType == nil || *defaultType != expectedType {
+		t.Errorf("Expected v1.HostPathVolumeSource default type %v, got %v", expectedType, defaultType)
+	}
+}

pkg/api/validation/validation.go

@@ -976,6 +976,7 @@ func validateProjectedVolumeSource(projection *api.ProjectedVolumeSource, fldPat
 }
 
 var supportedHostPathTypes = sets.NewString(
+	string(api.HostPathUnset),
 	string(api.HostPathDirectoryOrCreate),
 	string(api.HostPathDirectory),
 	string(api.HostPathFileOrCreate),

pkg/volume/host_path/host_path.go

@@ -214,6 +214,9 @@ func (b *hostPathMounter) SetUp(fsGroup *int64) error {
 		return fmt.Errorf("invalid HostPath `%s`: %v", b.GetPath(), err)
 	}
 
+	if *b.pathType == v1.HostPathUnset {
+		return nil
+	}
 	return checkType(b.GetPath(), b.pathType)
 }
 

pkg/volume/host_path/host_path_test.go

@@ -554,7 +554,7 @@ func TestHostPathTypeCheckerInternal(t *testing.T) {
 			isFile:        false,
 			exists:        false,
 			validpathType: newHostPathTypeList(string(v1.HostPathFileOrCreate)),
-			invalidpathType: newHostPathTypeList(string(v1.HostPathFile), string(v1.HostPathDirectory),
+			invalidpathType: newHostPathTypeList(string(v1.HostPathDirectory),
 				string(v1.HostPathSocket), string(v1.HostPathCharDev), string(v1.HostPathBlockDev)),
 		},
 		{

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

@@ -684,6 +684,8 @@ const (
 type HostPathType string
 
 const (
+	// For backwards compatible, leave it empty if unset
+	HostPathUnset HostPathType = ""
 	// If nothing exists at the given path, an empty directory will be created there
 	// as needed with file mode 0755, having the same group and ownership with Kubelet.
 	HostPathDirectoryOrCreate HostPathType = "DirectoryOrCreate"
@@ -710,7 +712,7 @@ type HostPathVolumeSource struct {
 	// More info: https://kubernetes.io/docs/concepts/storage/volumes#hostpath
 	Path string `json:"path" protobuf:"bytes,1,opt,name=path"`
 	// Type for HostPath Volume
-	// Defaults to DirectoryOrCreate
+	// Defaults to ""
 	// More info: https://kubernetes.io/docs/concepts/storage/volumes#hostpath
 	// +optional
 	Type *HostPathType `json:"type,omitempty" protobuf:"bytes,2,opt,name=type"`