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
```

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
 }