add volume stats metrics

go.mod

@@ -13,6 +13,7 @@ require (
 	github.com/onsi/ginkgo v1.10.2
 	github.com/onsi/gomega v1.7.0
 	github.com/tmc/grpc-websocket-proxy v0.0.0-20171017195756-830351dc03c6 // indirect
+	golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f
 	google.golang.org/grpc v1.26.0
 	k8s.io/api v0.17.3
 	k8s.io/apimachinery v0.17.3

pkg/driver/node.go

@@ -22,6 +22,7 @@ import (
 	"os"
 	"path/filepath"
 	"regexp"
+	"strconv"
 	"strings"
 
 	csi "github.com/container-storage-interface/spec/lib/go/csi"
@@ -65,13 +66,15 @@ var (
 	nodeCaps = []csi.NodeServiceCapability_RPC_Type{
 		csi.NodeServiceCapability_RPC_STAGE_UNSTAGE_VOLUME,
 		csi.NodeServiceCapability_RPC_EXPAND_VOLUME,
+		csi.NodeServiceCapability_RPC_GET_VOLUME_STATS,
 	}
 )
 
 // nodeService represents the node service of CSI driver
 type nodeService struct {
 	metadata      cloud.MetadataService
 	mounter       Mounter
+	statter       Statter
 	inFlight      *internal.InFlight
 	driverOptions *DriverOptions
 }
@@ -87,6 +90,7 @@ func newNodeService(driverOptions *DriverOptions) nodeService {
 	return nodeService{
 		metadata:      metadata,
 		mounter:       newNodeMounter(),
+		statter:       NewStatter(),
 		inFlight:      internal.NewInFlight(),
 		driverOptions: driverOptions,
 	}
@@ -344,7 +348,64 @@ func (d *nodeService) NodeUnpublishVolume(ctx context.Context, req *csi.NodeUnpu
 }
 
 func (d *nodeService) NodeGetVolumeStats(ctx context.Context, req *csi.NodeGetVolumeStatsRequest) (*csi.NodeGetVolumeStatsResponse, error) {
-	return nil, status.Error(codes.Unimplemented, "NodeGetVolumeStats is not implemented yet")
+	klog.V(4).Infof("NodeGetVolumeStats: called with args %+v", *req)
+	if len(req.VolumeId) == 0 {
+		return nil, status.Error(codes.InvalidArgument, "NodeGetVolumeStats volume ID was empty")
+	}
+	if len(req.VolumePath) == 0 {
+		return nil, status.Error(codes.InvalidArgument, "NodeGetVolumeStats volume path was empty")
+	}
+
+	exists, err := d.mounter.ExistsPath(req.VolumePath)
+	if err != nil {
+		return nil, status.Errorf(codes.Internal, "unknown error when stat on %s: %v", req.VolumePath, err)
+	}
+	if !exists {
+		return nil, status.Errorf(codes.NotFound, "path %s does not exist", req.VolumePath)
+	}
+
+	isBlock, err := d.statter.IsBlockDevice(req.VolumePath)
+	if err != nil {
+		return nil, status.Errorf(codes.Internal, "failed to determine whether %s is block device: %v", req.VolumePath, err)
+	}
+	if isBlock {
+		bcap, err := d.getBlockSizeBytes(req.VolumePath)
+		if err != nil {
+			return nil, status.Errorf(codes.Internal, "failed to get block capacity on path %s: %v", req.VolumePath, err)
+		}
+		return &csi.NodeGetVolumeStatsResponse{
+			Usage: []*csi.VolumeUsage{
+				{
+					Unit:  csi.VolumeUsage_BYTES,
+					Total: bcap,
+				},
+			},
+		}, nil
+	}
+
+	available, capacity, used, inodesFree, inodes, inodesUsed, err := d.statter.StatFS(req.VolumePath)
+	if err != nil {
+		return nil, status.Errorf(codes.Internal, "failed to get fs info on path %s: %v", req.VolumePath, err)
+	}
+
+	return &csi.NodeGetVolumeStatsResponse{
+		Usage: []*csi.VolumeUsage{
+			{
+				Available: available,
+				Total:     capacity,
+				Used:      used,
+				Unit:      csi.VolumeUsage_BYTES,
+			},
+
+			{
+				Available: inodesFree,
+				Total:     inodes,
+				Used:      inodesUsed,
+				Unit:      csi.VolumeUsage_INODES,
+			},
+		},
+	}, nil
+
 }
 
 func (d *nodeService) NodeGetCapabilities(ctx context.Context, req *csi.NodeGetCapabilitiesRequest) (*csi.NodeGetCapabilitiesResponse, error) {
@@ -550,3 +611,17 @@ func hasMountOption(options []string, opt string) bool {
 	}
 	return false
 }
+
+func (d *nodeService) getBlockSizeBytes(devicePath string) (int64, error) {
+	cmd := d.mounter.Command("blockdev", "--getsize64", devicePath)
+	output, err := cmd.Output()
+	if err != nil {
+		return -1, fmt.Errorf("error when getting size of block volume at path %s: output: %s, err: %v", devicePath, string(output), err)
+	}
+	strOut := strings.TrimSpace(string(output))
+	gotSizeBytes, err := strconv.ParseInt(strOut, 10, 64)
+	if err != nil {
+		return -1, fmt.Errorf("failed to parse size %s into int a size", strOut)
+	}
+	return gotSizeBytes, nil
+}

pkg/driver/node_test.go

@@ -1175,26 +1175,23 @@ func TestNodeGetVolumeStats(t *testing.T) {
 
 	mockMetadata := mocks.NewMockMetadataService(mockCtl)
 	mockMounter := mocks.NewMockMounter(mockCtl)
+	VolumePath := "/test"
 
+	mockMounter.EXPECT().ExistsPath(VolumePath).Return(true, nil)
 	awsDriver := nodeService{
 		metadata: mockMetadata,
 		mounter:  mockMounter,
+		statter:  NewFakeStatter(),
 		inFlight: internal.NewInFlight(),
 	}
 
-	expErrCode := codes.Unimplemented
-
-	req := &csi.NodeGetVolumeStatsRequest{}
-	_, err := awsDriver.NodeGetVolumeStats(context.TODO(), req)
-	if err == nil {
-		t.Fatalf("Expected error code %d, got nil", expErrCode)
-	}
-	srvErr, ok := status.FromError(err)
-	if !ok {
-		t.Fatalf("Could not get error status code from error: %v", srvErr)
+	req := &csi.NodeGetVolumeStatsRequest{
+		VolumeId:   "vol-test",
+		VolumePath: VolumePath,
 	}
-	if srvErr.Code() != expErrCode {
-		t.Fatalf("Expected error code %d, got %d message %s", expErrCode, srvErr.Code(), srvErr.Message())
+	_, err := awsDriver.NodeGetVolumeStats(context.TODO(), req)
+	if err != nil {
+		t.Fatalf("Expected no error, got %v", err)
 	}
 }
 
@@ -1226,6 +1223,13 @@ func TestNodeGetCapabilities(t *testing.T) {
 				},
 			},
 		},
+		{
+			Type: &csi.NodeServiceCapability_Rpc{
+				Rpc: &csi.NodeServiceCapability_RPC{
+					Type: csi.NodeServiceCapability_RPC_GET_VOLUME_STATS,
+				},
+			},
+		},
 	}
 	expResp := &csi.NodeGetCapabilitiesResponse{Capabilities: caps}
 

pkg/driver/statter.go

@@ -0,0 +1,80 @@
+/*
+Copyright 2019 The Kubernetes Authors.
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+    http://www.apache.org/licenses/LICENSE-2.0
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package driver
+
+import (
+	"fmt"
+
+	"golang.org/x/sys/unix"
+)
+
+type Statter interface {
+	StatFS(path string) (int64, int64, int64, int64, int64, int64, error)
+	IsBlockDevice(string) (bool, error)
+}
+
+var _ Statter = realStatter{}
+
+type realStatter struct {
+}
+
+func NewStatter() realStatter {
+	return realStatter{}
+}
+
+// IsBlock checks if the given path is a block device
+func (realStatter) IsBlockDevice(fullPath string) (bool, error) {
+	var st unix.Stat_t
+	err := unix.Stat(fullPath, &st)
+	if err != nil {
+		return false, err
+	}
+
+	return (st.Mode & unix.S_IFMT) == unix.S_IFBLK, nil
+}
+
+func (realStatter) StatFS(path string) (available, capacity, used, inodesFree, inodes, inodesUsed int64, err error) {
+	statfs := &unix.Statfs_t{}
+	err = unix.Statfs(path, statfs)
+	if err != nil {
+		err = fmt.Errorf("failed to get fs info on path %s: %v", path, err)
+		return
+	}
+
+	// Available is blocks available * fragment size
+	available = int64(statfs.Bavail) * int64(statfs.Bsize)
+	// Capacity is total block count * fragment size
+	capacity = int64(statfs.Blocks) * int64(statfs.Bsize)
+	// Usage is block being used * fragment size (aka block size).
+	used = (int64(statfs.Blocks) - int64(statfs.Bfree)) * int64(statfs.Bsize)
+	inodes = int64(statfs.Files)
+	inodesFree = int64(statfs.Ffree)
+	inodesUsed = inodes - inodesFree
+	return
+}
+
+type fakeStatter struct{}
+
+func NewFakeStatter() fakeStatter {
+	return fakeStatter{}
+}
+
+func (fakeStatter) StatFS(path string) (available, capacity, used, inodesFree, inodes, inodesUsed int64, err error) {
+	// Assume the file exists and give some dummy values back
+	return 1, 1, 1, 1, 1, 1, nil
+}
+
+func (fakeStatter) IsBlockDevice(fullPath string) (bool, error) {
+	return false, nil
+}