Set FsId and usedBytes for windows image file system

pkg/kubelet/dockershim/BUILD

@@ -127,6 +127,7 @@ go_library(
     ] + select({
         "@io_bazel_rules_go//go/platform:windows": [
             "//pkg/features:go_default_library",
+            "//pkg/kubelet/winstats:go_default_library",
             "//vendor/k8s.io/apiserver/pkg/util/feature:go_default_library",
         ],
         "//conditions:default": [],

pkg/kubelet/dockershim/docker_image_windows.go

@@ -21,19 +21,36 @@ package dockershim
 import (
 	"time"
 
+	"github.com/golang/glog"
 	"golang.org/x/net/context"
 
 	runtimeapi "k8s.io/kubernetes/pkg/kubelet/apis/cri/runtime/v1alpha2"
+	"k8s.io/kubernetes/pkg/kubelet/winstats"
 )
 
 // ImageFsInfo returns information of the filesystem that is used to store images.
 func (ds *dockerService) ImageFsInfo(_ context.Context, _ *runtimeapi.ImageFsInfoRequest) (*runtimeapi.ImageFsInfoResponse, error) {
-	// For Windows Stats to work correctly, a file system must be provided. For now, provide a fake filesystem.
+	info, err := ds.client.Info()
+	if err != nil {
+		glog.Errorf("Failed to get docker info: %v", err)
+		return nil, err
+	}
+
+	statsClient := &winstats.StatsClient{}
+	fsinfo, err := statsClient.GetDirFsInfo(info.DockerRootDir)
+	if err != nil {
+		glog.Errorf("Failed to get dir fsInfo for %q: %v", info.DockerRootDir, err)
+		return nil, err
+	}
+
 	filesystems := []*runtimeapi.FilesystemUsage{
 		{
 			Timestamp:  time.Now().UnixNano(),
-			UsedBytes:  &runtimeapi.UInt64Value{Value: 0},
+			UsedBytes:  &runtimeapi.UInt64Value{Value: fsinfo.Usage},
 			InodesUsed: &runtimeapi.UInt64Value{Value: 0},
+			FsId: &runtimeapi.FilesystemIdentifier{
+				Mountpoint: info.DockerRootDir,
+			},
 		},
 	}