Merge pull request #55204 from vladimirvivien/k8s-csi-volume-source

Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Kubernetes CSI - Persistent Volume Source Type

**What this PR does / why we need it**:
This PR is to track the addition of new API type `CSIPersistentVolumeSource` that will be used as PersistentVolume for storage sources managed by CSI drivers. 

**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
xref https://github.com/kubernetes/features/issues/178

**Special notes for your reviewer**:
- Implements API `PersistentVolume` type `CSIPersistentVolumeSource`
- Part of implementation for https://github.com/kubernetes/features/issues/178
- Designed at https://github.com/kubernetes/community/pull/1258

Other CSI Volume Plugin PRs:
- Plugin Mounter/Unmounter https://github.com/kubernetes/kubernetes/pull/54529
- Plugin Attacher/Detacher https://github.com/kubernetes/kubernetes/pull/55809

**Release note**:

```release-note
NONE
```

api/openapi-spec/swagger.json

@@ -73464,6 +73464,27 @@
      }
     ]
    },
+   "io.k8s.api.core.v1.CSIPersistentVolumeSource": {
+    "description": "Represents storage that is managed by an external CSI volume driver",
+    "required": [
+     "driver",
+     "volumeHandle"
+    ],
+    "properties": {
+     "driver": {
+      "description": "Driver is the name of the driver to use for this volume. Required.",
+      "type": "string"
+     },
+     "readOnly": {
+      "description": "Optional: The value to pass to ControllerPublishVolumeRequest. Defaults to false (read/write).",
+      "type": "boolean"
+     },
+     "volumeHandle": {
+      "description": "VolumeHandle is the unique volume name returned by the CSI volume plugin’s CreateVolume to refer to the volume on all subsequent calls. Required.",
+      "type": "string"
+     }
+    }
+   },
    "io.k8s.api.core.v1.Capabilities": {
     "description": "Adds and removes POSIX capabilities from running containers.",
     "properties": {
@@ -75812,6 +75833,10 @@
       "description": "ClaimRef is part of a bi-directional binding between PersistentVolume and PersistentVolumeClaim. Expected to be non-nil when bound. claim.VolumeName is the authoritative bind between PV and PVC. More info: https://kubernetes.io/docs/concepts/storage/persistent-volumes#binding",
       "$ref": "#/definitions/io.k8s.api.core.v1.ObjectReference"
      },
+     "csi": {
+      "description": "CSI represents storage that handled by an external CSI driver",
+      "$ref": "#/definitions/io.k8s.api.core.v1.CSIPersistentVolumeSource"
+     },
      "fc": {
       "description": "FC represents a Fibre Channel resource that is attached to a kubelet's host machine and then exposed to the pod.",
       "$ref": "#/definitions/io.k8s.api.core.v1.FCVolumeSource"

api/swagger-spec/v1.json

@@ -20592,6 +20592,10 @@
       "$ref": "v1.StorageOSPersistentVolumeSource",
       "description": "StorageOS represents a StorageOS volume that is attached to the kubelet's host machine and mounted into the pod More info: https://releases.k8s.io/HEAD/examples/volumes/storageos/README.md"
      },
+     "csi": {
+      "$ref": "v1.CSIPersistentVolumeSource",
+      "description": "CSI represents storage that handled by an external CSI driver"
+     },
      "accessModes": {
       "type": "array",
       "items": {
@@ -21250,6 +21254,28 @@
      }
     }
    },
+   "v1.CSIPersistentVolumeSource": {
+    "id": "v1.CSIPersistentVolumeSource",
+    "description": "Represents storage that is managed by an external CSI volume driver",
+    "required": [
+     "driver",
+     "volumeHandle"
+    ],
+    "properties": {
+     "driver": {
+      "type": "string",
+      "description": "Driver is the name of the driver to use for this volume. Required."
+     },
+     "volumeHandle": {
+      "type": "string",
+      "description": "VolumeHandle is the unique volume name returned by the CSI volume plugin’s CreateVolume to refer to the volume on all subsequent calls. Required."
+     },
+     "readOnly": {
+      "type": "boolean",
+      "description": "Optional: The value to pass to ControllerPublishVolumeRequest. Defaults to false (read/write)."
+     }
+    }
+   },
    "v1.PersistentVolumeStatus": {
     "id": "v1.PersistentVolumeStatus",
     "description": "PersistentVolumeStatus is the current status of a persistent volume.",

docs/api-reference/v1/definitions.html

@@ -3651,6 +3651,54 @@ The resulting set of endpoints can be viewed as:<br>
 </tbody>
 </table>
 
+</div>
+<div class="sect2">
+<h3 id="_v1_csipersistentvolumesource">v1.CSIPersistentVolumeSource</h3>
+<div class="paragraph">
+<p>Represents storage that is managed by an external CSI volume driver</p>
+</div>
+<table class="tableblock frame-all grid-all" style="width:100%; ">
+<colgroup>
+<col style="width:20%;">
+<col style="width:20%;">
+<col style="width:20%;">
+<col style="width:20%;">
+<col style="width:20%;"> 
+</colgroup>
+<thead>
+<tr>
+<th class="tableblock halign-left valign-top">Name</th>
+<th class="tableblock halign-left valign-top">Description</th>
+<th class="tableblock halign-left valign-top">Required</th>
+<th class="tableblock halign-left valign-top">Schema</th>
+<th class="tableblock halign-left valign-top">Default</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td class="tableblock halign-left valign-top"><p class="tableblock">driver</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">Driver is the name of the driver to use for this volume. Required.</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">true</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">string</p></td>
+<td class="tableblock halign-left valign-top"></td>
+</tr>
+<tr>
+<td class="tableblock halign-left valign-top"><p class="tableblock">volumeHandle</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">VolumeHandle is the unique volume name returned by the CSI volume plugin’s CreateVolume to refer to the volume on all subsequent calls. Required.</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">true</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">string</p></td>
+<td class="tableblock halign-left valign-top"></td>
+</tr>
+<tr>
+<td class="tableblock halign-left valign-top"><p class="tableblock">readOnly</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">Optional: The value to pass to ControllerPublishVolumeRequest. Defaults to false (read/write).</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">false</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">boolean</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">false</p></td>
+</tr>
+</tbody>
+</table>
+
 </div>
 <div class="sect2">
 <h3 id="_v1_persistentvolumeclaimcondition">v1.PersistentVolumeClaimCondition</h3>
@@ -7745,6 +7793,13 @@ Examples:<br>
 <td class="tableblock halign-left valign-top"></td>
 </tr>
 <tr>
+<td class="tableblock halign-left valign-top"><p class="tableblock">csi</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">CSI represents storage that handled by an external CSI driver</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">false</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock"><a href="#_v1_csipersistentvolumesource">v1.CSIPersistentVolumeSource</a></p></td>
+<td class="tableblock halign-left valign-top"></td>
+</tr>
+<tr>
 <td class="tableblock halign-left valign-top"><p class="tableblock">accessModes</p></td>
 <td class="tableblock halign-left valign-top"><p class="tableblock">AccessModes contains all ways the volume can be mounted. More info: <a href="https://kubernetes.io/docs/concepts/storage/persistent-volumes#access-modes">https://kubernetes.io/docs/concepts/storage/persistent-volumes#access-modes</a></p></td>
 <td class="tableblock halign-left valign-top"><p class="tableblock">false</p></td>

pkg/apis/core/types.go

@@ -391,6 +391,9 @@ type PersistentVolumeSource struct {
 	// More info: https://releases.k8s.io/HEAD/examples/volumes/storageos/README.md
 	// +optional
 	StorageOS *StorageOSPersistentVolumeSource
+	// CSI (Container Storage Interface) represents storage that handled by an external CSI driver
+	// +optional
+	CSI *CSIPersistentVolumeSource
 }
 
 type PersistentVolumeClaimVolumeSource struct {
@@ -1503,6 +1506,23 @@ type LocalVolumeSource struct {
 	Path string
 }
 
+// Represents storage that is managed by an external CSI volume driver
+type CSIPersistentVolumeSource struct {
+	// Driver is the name of the driver to use for this volume.
+	// Required.
+	Driver string
+
+	// VolumeHandle is the unique volume name returned by the CSI volume
+	// plugin’s CreateVolume to refer to the volume on all subsequent calls.
+	// Required.
+	VolumeHandle string
+
+	// Optional: The value to pass to ControllerPublishVolumeRequest.
+	// Defaults to false (read/write).
+	// +optional
+	ReadOnly bool
+}
+
 // ContainerPort represents a network port in a single container
 type ContainerPort struct {
 	// Optional: If specified, this must be an IANA_SVC_NAME  Each named port

pkg/apis/core/v1/zz_generated.conversion.go

@@ -55,6 +55,8 @@ func RegisterConversions(scheme *runtime.Scheme) error {
 		Convert_core_AzureFileVolumeSource_To_v1_AzureFileVolumeSource,
 		Convert_v1_Binding_To_core_Binding,
 		Convert_core_Binding_To_v1_Binding,
+		Convert_v1_CSIPersistentVolumeSource_To_core_CSIPersistentVolumeSource,
+		Convert_core_CSIPersistentVolumeSource_To_v1_CSIPersistentVolumeSource,
 		Convert_v1_Capabilities_To_core_Capabilities,
 		Convert_core_Capabilities_To_v1_Capabilities,
 		Convert_v1_CephFSPersistentVolumeSource_To_core_CephFSPersistentVolumeSource,
@@ -600,6 +602,30 @@ func Convert_core_Binding_To_v1_Binding(in *core.Binding, out *v1.Binding, s con
 	return autoConvert_core_Binding_To_v1_Binding(in, out, s)
 }
 
+func autoConvert_v1_CSIPersistentVolumeSource_To_core_CSIPersistentVolumeSource(in *v1.CSIPersistentVolumeSource, out *core.CSIPersistentVolumeSource, s conversion.Scope) error {
+	out.Driver = in.Driver
+	out.VolumeHandle = in.VolumeHandle
+	out.ReadOnly = in.ReadOnly
+	return nil
+}
+
+// Convert_v1_CSIPersistentVolumeSource_To_core_CSIPersistentVolumeSource is an autogenerated conversion function.
+func Convert_v1_CSIPersistentVolumeSource_To_core_CSIPersistentVolumeSource(in *v1.CSIPersistentVolumeSource, out *core.CSIPersistentVolumeSource, s conversion.Scope) error {
+	return autoConvert_v1_CSIPersistentVolumeSource_To_core_CSIPersistentVolumeSource(in, out, s)
+}
+
+func autoConvert_core_CSIPersistentVolumeSource_To_v1_CSIPersistentVolumeSource(in *core.CSIPersistentVolumeSource, out *v1.CSIPersistentVolumeSource, s conversion.Scope) error {
+	out.Driver = in.Driver
+	out.VolumeHandle = in.VolumeHandle
+	out.ReadOnly = in.ReadOnly
+	return nil
+}
+
+// Convert_core_CSIPersistentVolumeSource_To_v1_CSIPersistentVolumeSource is an autogenerated conversion function.
+func Convert_core_CSIPersistentVolumeSource_To_v1_CSIPersistentVolumeSource(in *core.CSIPersistentVolumeSource, out *v1.CSIPersistentVolumeSource, s conversion.Scope) error {
+	return autoConvert_core_CSIPersistentVolumeSource_To_v1_CSIPersistentVolumeSource(in, out, s)
+}
+
 func autoConvert_v1_Capabilities_To_core_Capabilities(in *v1.Capabilities, out *core.Capabilities, s conversion.Scope) error {
 	out.Add = *(*[]core.Capability)(unsafe.Pointer(&in.Add))
 	out.Drop = *(*[]core.Capability)(unsafe.Pointer(&in.Drop))
@@ -3144,6 +3170,7 @@ func autoConvert_v1_PersistentVolumeSource_To_core_PersistentVolumeSource(in *v1
 	out.ScaleIO = (*core.ScaleIOPersistentVolumeSource)(unsafe.Pointer(in.ScaleIO))
 	out.Local = (*core.LocalVolumeSource)(unsafe.Pointer(in.Local))
 	out.StorageOS = (*core.StorageOSPersistentVolumeSource)(unsafe.Pointer(in.StorageOS))
+	out.CSI = (*core.CSIPersistentVolumeSource)(unsafe.Pointer(in.CSI))
 	return nil
 }
 
@@ -3174,6 +3201,7 @@ func autoConvert_core_PersistentVolumeSource_To_v1_PersistentVolumeSource(in *co
 	out.ScaleIO = (*v1.ScaleIOPersistentVolumeSource)(unsafe.Pointer(in.ScaleIO))
 	out.Local = (*v1.LocalVolumeSource)(unsafe.Pointer(in.Local))
 	out.StorageOS = (*v1.StorageOSPersistentVolumeSource)(unsafe.Pointer(in.StorageOS))
+	out.CSI = (*v1.CSIPersistentVolumeSource)(unsafe.Pointer(in.CSI))
 	return nil
 }
 

pkg/apis/core/validation/validation.go

@@ -1318,6 +1318,24 @@ func validateStorageOSPersistentVolumeSource(storageos *core.StorageOSPersistent
 	return allErrs
 }
 
+func validateCSIPersistentVolumeSource(csi *core.CSIPersistentVolumeSource, fldPath *field.Path) field.ErrorList {
+	allErrs := field.ErrorList{}
+
+	if !utilfeature.DefaultFeatureGate.Enabled(features.CSIPersistentVolume) {
+		allErrs = append(allErrs, field.Forbidden(fldPath, "CSIPersistentVolume disabled by feature-gate"))
+	}
+
+	if len(csi.Driver) == 0 {
+		allErrs = append(allErrs, field.Required(fldPath.Child("driver"), ""))
+	}
+
+	if len(csi.VolumeHandle) == 0 {
+		allErrs = append(allErrs, field.Required(fldPath.Child("volumeHandle"), ""))
+	}
+
+	return allErrs
+}
+
 // ValidatePersistentVolumeName checks that a name is appropriate for a
 // PersistentVolumeName object.
 var ValidatePersistentVolumeName = NameIsDNSSubdomain
@@ -1541,6 +1559,15 @@ func ValidatePersistentVolume(pv *core.PersistentVolume) field.ErrorList {
 		}
 	}
 
+	if pv.Spec.CSI != nil {
+		if numVolumes > 0 {
+			allErrs = append(allErrs, field.Forbidden(specPath.Child("csi"), "may not specify more than 1 volume type"))
+		} else {
+			numVolumes++
+			allErrs = append(allErrs, validateCSIPersistentVolumeSource(pv.Spec.CSI, specPath.Child("csi"))...)
+		}
+	}
+
 	if numVolumes == 0 {
 		allErrs = append(allErrs, field.Required(specPath, "must specify a volume type"))
 	}

pkg/apis/core/validation/validation_test.go

@@ -1353,6 +1353,64 @@ func TestValidateGlusterfs(t *testing.T) {
 	}
 }
 
+func TestValidateCSIVolumeSource(t *testing.T) {
+	testCases := []struct {
+		name     string
+		csi      *api.CSIPersistentVolumeSource
+		errtype  field.ErrorType
+		errfield string
+	}{
+		{
+			name: "all required fields ok",
+			csi:  &api.CSIPersistentVolumeSource{Driver: "test-driver", VolumeHandle: "test-123", ReadOnly: true},
+		},
+		{
+			name: "with default values ok",
+			csi:  &api.CSIPersistentVolumeSource{Driver: "test-driver", VolumeHandle: "test-123"},
+		},
+		{
+			name:     "missing driver name",
+			csi:      &api.CSIPersistentVolumeSource{VolumeHandle: "test-123"},
+			errtype:  field.ErrorTypeRequired,
+			errfield: "driver",
+		},
+		{
+			name:     "missing volume handle",
+			csi:      &api.CSIPersistentVolumeSource{Driver: "my-driver"},
+			errtype:  field.ErrorTypeRequired,
+			errfield: "volumeHandle",
+		},
+	}
+
+	err := utilfeature.DefaultFeatureGate.Set("CSIPersistentVolume=true")
+	if err != nil {
+		t.Errorf("Failed to enable feature gate for CSIPersistentVolumes: %v", err)
+		return
+	}
+
+	for i, tc := range testCases {
+		errs := validateCSIPersistentVolumeSource(tc.csi, field.NewPath("field"))
+
+		if len(errs) > 0 && tc.errtype == "" {
+			t.Errorf("[%d: %q] unexpected error(s): %v", i, tc.name, errs)
+		} else if len(errs) == 0 && tc.errtype != "" {
+			t.Errorf("[%d: %q] expected error type %v", i, tc.name, tc.errtype)
+		} else if len(errs) >= 1 {
+			if errs[0].Type != tc.errtype {
+				t.Errorf("[%d: %q] expected error type %v, got %v", i, tc.name, tc.errtype, errs[0].Type)
+			} else if !strings.HasSuffix(errs[0].Field, "."+tc.errfield) {
+				t.Errorf("[%d: %q] expected error on field %q, got %q", i, tc.name, tc.errfield, errs[0].Field)
+			}
+		}
+	}
+	err = utilfeature.DefaultFeatureGate.Set("CSIPersistentVolume=false")
+	if err != nil {
+		t.Errorf("Failed to disable feature gate for CSIPersistentVolumes: %v", err)
+		return
+	}
+
+}
+
 // helper
 func newInt32(val int) *int32 {
 	p := new(int32)

pkg/apis/core/zz_generated.deepcopy.go

@@ -246,6 +246,22 @@ func (in *Binding) DeepCopyObject() runtime.Object {
 	}
 }
 
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *CSIPersistentVolumeSource) DeepCopyInto(out *CSIPersistentVolumeSource) {
+	*out = *in
+	return
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new CSIPersistentVolumeSource.
+func (in *CSIPersistentVolumeSource) DeepCopy() *CSIPersistentVolumeSource {
+	if in == nil {
+		return nil
+	}
+	out := new(CSIPersistentVolumeSource)
+	in.DeepCopyInto(out)
+	return out
+}
+
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *Capabilities) DeepCopyInto(out *Capabilities) {
 	*out = *in
@@ -3159,6 +3175,15 @@ func (in *PersistentVolumeSource) DeepCopyInto(out *PersistentVolumeSource) {
 			(*in).DeepCopyInto(*out)
 		}
 	}
+	if in.CSI != nil {
+		in, out := &in.CSI, &out.CSI
+		if *in == nil {
+			*out = nil
+		} else {
+			*out = new(CSIPersistentVolumeSource)
+			**out = **in
+		}
+	}
 	return
 }
 

pkg/apis/extensions/types.go

@@ -919,6 +919,7 @@ var (
 	Projected             FSType = "projected"
 	PortworxVolume        FSType = "portworxVolume"
 	ScaleIO               FSType = "scaleIO"
+	CSI                   FSType = "csi"
 	All                   FSType = "*"
 )
 

pkg/features/kube_features.go

@@ -181,6 +181,12 @@ const (
 	//
 	// Extend the default scheduler to be aware of PV topology and handle PV binding
 	VolumeScheduling utilfeature.Feature = "VolumeScheduling"
+
+	// owner: @vladimirvivien
+	// alpha: v1.9
+	//
+	// Enable mount/attachment of Container Storage Interface (CSI) backed PVs
+	CSIPersistentVolume utilfeature.Feature = "CSIPersistentVolume"
 )
 
 func init() {
@@ -215,6 +221,7 @@ var defaultKubernetesFeatureGates = map[utilfeature.Feature]utilfeature.FeatureS
 	ServiceNodeExclusion:                        {Default: false, PreRelease: utilfeature.Alpha},
 	MountContainers:                             {Default: false, PreRelease: utilfeature.Alpha},
 	VolumeScheduling:                            {Default: false, PreRelease: utilfeature.Alpha},
+	CSIPersistentVolume:                         {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/printers/internalversion/describe.go

@@ -1073,6 +1073,14 @@ func printFlockerVolumeSource(flocker *api.FlockerVolumeSource, w PrefixWriter)
 		flocker.DatasetName, flocker.DatasetUUID)
 }
 
+func printCSIPersistentVolumeSource(csi *api.CSIPersistentVolumeSource, w PrefixWriter) {
+	w.Write(LEVEL_2, "Type:\tCSI (a Container Storage Interface (CSI) volume source)\n"+
+		"    Driver:\t%v\n"+
+		"    VolumeHandle:\t%v\n",
+		"    ReadOnly:\t%v\n",
+		csi.Driver, csi.VolumeHandle, csi.ReadOnly)
+}
+
 type PersistentVolumeDescriber struct {
 	clientset.Interface
 }
@@ -1156,6 +1164,8 @@ func describePersistentVolume(pv *api.PersistentVolume, events *api.EventList) (
 			printFlexVolumeSource(pv.Spec.FlexVolume, w)
 		case pv.Spec.Flocker != nil:
 			printFlockerVolumeSource(pv.Spec.Flocker, w)
+		case pv.Spec.CSI != nil:
+			printCSIPersistentVolumeSource(pv.Spec.CSI, w)
 		default:
 			w.Write(LEVEL_1, "<unknown>\n")
 		}

pkg/security/podsecuritypolicy/util/util.go

@@ -67,6 +67,7 @@ func GetAllFSTypesAsSet() sets.String {
 		string(extensions.Projected),
 		string(extensions.PortworxVolume),
 		string(extensions.ScaleIO),
+		string(extensions.CSI),
 	)
 	return fstypes
 }

pkg/volume/BUILD

@@ -108,6 +108,7 @@ filegroup(
         "//pkg/volume/cephfs:all-srcs",
         "//pkg/volume/cinder:all-srcs",
         "//pkg/volume/configmap:all-srcs",
+        "//pkg/volume/csi:all-srcs",
         "//pkg/volume/downwardapi:all-srcs",
         "//pkg/volume/empty_dir:all-srcs",
         "//pkg/volume/fc:all-srcs",

pkg/volume/csi/BUILD

@@ -0,0 +1,33 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "csi_attacher.go",
+        "csi_mounter.go",
+        "csi_plugin.go",
+    ],
+    importpath = "k8s.io/kubernetes/pkg/volume/csi",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//pkg/util/mount:go_default_library",
+        "//pkg/util/strings:go_default_library",
+        "//pkg/volume:go_default_library",
+        "//vendor/k8s.io/api/core/v1:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/types:go_default_library",
+    ],
+)
+
+filegroup(
+    name = "package-srcs",
+    srcs = glob(["**"]),
+    tags = ["automanaged"],
+    visibility = ["//visibility:private"],
+)
+
+filegroup(
+    name = "all-srcs",
+    srcs = [":package-srcs"],
+    tags = ["automanaged"],
+    visibility = ["//visibility:public"],
+)

staging/src/k8s.io/api/core/v1/generated.proto

@@ -170,6 +170,23 @@ message Binding {
   optional ObjectReference target = 2;
 }
 
+// Represents storage that is managed by an external CSI volume driver
+message CSIPersistentVolumeSource {
+  // Driver is the name of the driver to use for this volume.
+  // Required.
+  optional string driver = 1;
+
+  // VolumeHandle is the unique volume name returned by the CSI volume
+  // plugin’s CreateVolume to refer to the volume on all subsequent calls.
+  // Required.
+  optional string volumeHandle = 2;
+
+  // Optional: The value to pass to ControllerPublishVolumeRequest.
+  // Defaults to false (read/write).
+  // +optional
+  optional bool readOnly = 3;
+}
+
 // Adds and removes POSIX capabilities from running containers.
 message Capabilities {
   // Added capabilities
@@ -2356,6 +2373,10 @@ message PersistentVolumeSource {
   // More info: https://releases.k8s.io/HEAD/examples/volumes/storageos/README.md
   // +optional
   optional StorageOSPersistentVolumeSource storageos = 21;
+
+  // CSI represents storage that handled by an external CSI driver
+  // +optional
+  optional CSIPersistentVolumeSource csi = 22;
 }
 
 // PersistentVolumeSpec is the specification of a persistent volume.

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

@@ -448,6 +448,9 @@ type PersistentVolumeSource struct {
 	// More info: https://releases.k8s.io/HEAD/examples/volumes/storageos/README.md
 	// +optional
 	StorageOS *StorageOSPersistentVolumeSource `json:"storageos,omitempty" protobuf:"bytes,21,opt,name=storageos"`
+	// CSI represents storage that handled by an external CSI driver
+	// +optional
+	CSI *CSIPersistentVolumeSource `json:"csi,omitempty" protobuf:"bytes,22,opt,name=csi"`
 }
 
 const (
@@ -1621,6 +1624,23 @@ type LocalVolumeSource struct {
 	Path string `json:"path" protobuf:"bytes,1,opt,name=path"`
 }
 
+// Represents storage that is managed by an external CSI volume driver
+type CSIPersistentVolumeSource struct {
+	// Driver is the name of the driver to use for this volume.
+	// Required.
+	Driver string `json:"driver" protobuf:"bytes,1,opt,name=driver"`
+
+	// VolumeHandle is the unique volume name returned by the CSI volume
+	// plugin’s CreateVolume to refer to the volume on all subsequent calls.
+	// Required.
+	VolumeHandle string `json:"volumeHandle" protobuf:"bytes,2,opt,name=volumeHandle"`
+
+	// Optional: The value to pass to ControllerPublishVolumeRequest.
+	// Defaults to false (read/write).
+	// +optional
+	ReadOnly bool `json:"readOnly,omitempty" protobuf:"varint,3,opt,name=readOnly"`
+}
+
 // ContainerPort represents a network port in a single container.
 type ContainerPort struct {
 	// If specified, this must be an IANA_SVC_NAME and unique within the pod. Each

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

@@ -116,6 +116,17 @@ func (Binding) SwaggerDoc() map[string]string {
 	return map_Binding
 }
 
+var map_CSIPersistentVolumeSource = map[string]string{
+	"":             "Represents storage that is managed by an external CSI volume driver",
+	"driver":       "Driver is the name of the driver to use for this volume. Required.",
+	"volumeHandle": "VolumeHandle is the unique volume name returned by the CSI volume plugin’s CreateVolume to refer to the volume on all subsequent calls. Required.",
+	"readOnly":     "Optional: The value to pass to ControllerPublishVolumeRequest. Defaults to false (read/write).",
+}
+
+func (CSIPersistentVolumeSource) SwaggerDoc() map[string]string {
+	return map_CSIPersistentVolumeSource
+}
+
 var map_Capabilities = map[string]string{
 	"":     "Adds and removes POSIX capabilities from running containers.",
 	"add":  "Added capabilities",
@@ -1212,6 +1223,7 @@ var map_PersistentVolumeSource = map[string]string{
 	"scaleIO":              "ScaleIO represents a ScaleIO persistent volume attached and mounted on Kubernetes nodes.",
 	"local":                "Local represents directly-attached storage with node affinity",
 	"storageos":            "StorageOS represents a StorageOS volume that is attached to the kubelet's host machine and mounted into the pod More info: https://releases.k8s.io/HEAD/examples/volumes/storageos/README.md",
+	"csi":                  "CSI represents storage that handled by an external CSI driver",
 }
 
 func (PersistentVolumeSource) SwaggerDoc() map[string]string {

staging/src/k8s.io/api/core/v1/zz_generated.deepcopy.go

@@ -246,6 +246,22 @@ func (in *Binding) DeepCopyObject() runtime.Object {
 	}
 }
 
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *CSIPersistentVolumeSource) DeepCopyInto(out *CSIPersistentVolumeSource) {
+	*out = *in
+	return
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new CSIPersistentVolumeSource.
+func (in *CSIPersistentVolumeSource) DeepCopy() *CSIPersistentVolumeSource {
+	if in == nil {
+		return nil
+	}
+	out := new(CSIPersistentVolumeSource)
+	in.DeepCopyInto(out)
+	return out
+}
+
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *Capabilities) DeepCopyInto(out *Capabilities) {
 	*out = *in
@@ -3145,6 +3161,15 @@ func (in *PersistentVolumeSource) DeepCopyInto(out *PersistentVolumeSource) {
 			(*in).DeepCopyInto(*out)
 		}
 	}
+	if in.CSI != nil {
+		in, out := &in.CSI, &out.CSI
+		if *in == nil {
+			*out = nil
+		} else {
+			*out = new(CSIPersistentVolumeSource)
+			**out = **in
+		}
+	}
 	return
 }