From 9dff902a365dc192d7032281e7c35d78ccd4ee3b Mon Sep 17 00:00:00 2001
From: Danielle Lancashire <dani@hashicorp.com>
Date: Tue, 18 Feb 2020 17:08:38 +0100
Subject: [PATCH] client: Implement ClientCSI.ControllerValidateVolume

---
 client/client_csi_endpoint.go      | 30 ++++++++++
 client/client_csi_endpoint_test.go | 89 ++++++++++++++++++++++++++++++
 client/structs/csi.go              | 11 ++++
 3 files changed, 130 insertions(+)

diff --git a/client/client_csi_endpoint.go b/client/client_csi_endpoint.go
index 6d3efab5b..0922f0dc6 100644
--- a/client/client_csi_endpoint.go
+++ b/client/client_csi_endpoint.go
@@ -30,6 +30,36 @@ var (
 	ErrPluginTypeError = errors.New("CSI Plugin loaded incorrectly")
 )
 
+// CSIControllerValidateVolume is used during volume registration to validate
+// that a volume exists and that the capabilities it was registered with are
+// supported by the CSI Plugin and external volume configuration.
+func (c *ClientCSI) CSIControllerValidateVolume(req *structs.ClientCSIControllerValidateVolumeRequest, resp *structs.ClientCSIControllerValidateVolumeResponse) error {
+	defer metrics.MeasureSince([]string{"client", "csi_controller", "validate_volume"}, time.Now())
+
+	if req.VolumeID == "" {
+		return errors.New("VolumeID is required")
+	}
+
+	if req.PluginID == "" {
+		return errors.New("PluginID is required")
+	}
+
+	plugin, err := c.findControllerPlugin(req.PluginID)
+	if err != nil {
+		return err
+	}
+	defer plugin.Close()
+
+	caps, err := csi.VolumeCapabilityFromStructs(req.AttachmentMode, req.AccessMode)
+	if err != nil {
+		return err
+	}
+
+	ctx, cancelFn := c.requestContext()
+	defer cancelFn()
+	return plugin.ControllerValidateCapabilties(ctx, req.VolumeID, caps)
+}
+
 // CSIControllerAttachVolume is used to attach a volume from a CSI Cluster to
 // the storage node provided in the request.
 //
diff --git a/client/client_csi_endpoint_test.go b/client/client_csi_endpoint_test.go
index 7af35aa49..4e5da6bd6 100644
--- a/client/client_csi_endpoint_test.go
+++ b/client/client_csi_endpoint_test.go
@@ -147,3 +147,92 @@ func TestClientCSI_CSIControllerAttachVolume(t *testing.T) {
 		})
 	}
 }
+
+func TestClientCSI_CSIControllerValidateVolume(t *testing.T) {
+	t.Parallel()
+
+	cases := []struct {
+		Name             string
+		ClientSetupFunc  func(*fake.Client)
+		Request          *structs.ClientCSIControllerValidateVolumeRequest
+		ExpectedErr      error
+		ExpectedResponse *structs.ClientCSIControllerValidateVolumeResponse
+	}{
+		{
+			Name: "validates volumeid is not empty",
+			Request: &structs.ClientCSIControllerValidateVolumeRequest{
+				PluginID: fakePlugin.Name,
+			},
+			ExpectedErr: errors.New("VolumeID is required"),
+		},
+		{
+			Name: "returns plugin not found errors",
+			Request: &structs.ClientCSIControllerValidateVolumeRequest{
+				PluginID: "some-garbage",
+				VolumeID: "foo",
+			},
+			ExpectedErr: errors.New("plugin some-garbage for type csi-controller not found"),
+		},
+		{
+			Name: "validates attachmentmode",
+			Request: &structs.ClientCSIControllerValidateVolumeRequest{
+				PluginID:       fakePlugin.Name,
+				VolumeID:       "1234-4321-1234-4321",
+				AttachmentMode: nstructs.CSIVolumeAttachmentMode("bar"),
+				AccessMode:     nstructs.CSIVolumeAccessModeMultiNodeReader,
+			},
+			ExpectedErr: errors.New("Unknown volume attachment mode: bar"),
+		},
+		{
+			Name: "validates AccessMode",
+			Request: &structs.ClientCSIControllerValidateVolumeRequest{
+				PluginID:       fakePlugin.Name,
+				VolumeID:       "1234-4321-1234-4321",
+				AttachmentMode: nstructs.CSIVolumeAttachmentModeFilesystem,
+				AccessMode:     nstructs.CSIVolumeAccessMode("foo"),
+			},
+			ExpectedErr: errors.New("Unknown volume access mode: foo"),
+		},
+		{
+			Name: "returns transitive errors",
+			ClientSetupFunc: func(fc *fake.Client) {
+				fc.NextControllerValidateVolumeErr = errors.New("hello")
+			},
+			Request: &structs.ClientCSIControllerValidateVolumeRequest{
+				PluginID:       fakePlugin.Name,
+				VolumeID:       "1234-4321-1234-4321",
+				AccessMode:     nstructs.CSIVolumeAccessModeSingleNodeWriter,
+				AttachmentMode: nstructs.CSIVolumeAttachmentModeFilesystem,
+			},
+			ExpectedErr: errors.New("hello"),
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.Name, func(t *testing.T) {
+			require := require.New(t)
+			client, cleanup := TestClient(t, nil)
+			defer cleanup()
+
+			fakeClient := &fake.Client{}
+			if tc.ClientSetupFunc != nil {
+				tc.ClientSetupFunc(fakeClient)
+			}
+
+			dispenserFunc := func(*dynamicplugins.PluginInfo) (interface{}, error) {
+				return fakeClient, nil
+			}
+			client.dynamicRegistry.StubDispenserForType(dynamicplugins.PluginTypeCSIController, dispenserFunc)
+
+			err := client.dynamicRegistry.RegisterPlugin(fakePlugin)
+			require.Nil(err)
+
+			var resp structs.ClientCSIControllerValidateVolumeResponse
+			err = client.ClientRPC("ClientCSI.CSIControllerValidateVolume", tc.Request, &resp)
+			require.Equal(tc.ExpectedErr, err)
+			if tc.ExpectedResponse != nil {
+				require.Equal(tc.ExpectedResponse, &resp)
+			}
+		})
+	}
+}
diff --git a/client/structs/csi.go b/client/structs/csi.go
index 9616d1b78..6b9f891be 100644
--- a/client/structs/csi.go
+++ b/client/structs/csi.go
@@ -20,6 +20,17 @@ type CSIVolumeMountOptions struct {
 	MountFlags []string
 }
 
+type ClientCSIControllerValidateVolumeRequest struct {
+	PluginID string
+	VolumeID string
+
+	AttachmentMode structs.CSIVolumeAttachmentMode
+	AccessMode     structs.CSIVolumeAccessMode
+}
+
+type ClientCSIControllerValidateVolumeResponse struct {
+}
+
 type ClientCSIControllerAttachVolumeRequest struct {
 	PluginName string