unittests: Adds winstats unittests

The module pkg/kubelet/winstats has almost no coverage for Windows. This
commit adds unit tests to cover the mentioned module.

pkg/kubelet/winstats/network_stats.go

@@ -40,14 +40,14 @@ const (
 
 // networkCounter contains the counters for network adapters.
 type networkCounter struct {
-	packetsReceivedPerSecondCounter *perfCounter
-	packetsSentPerSecondCounter     *perfCounter
-	bytesReceivedPerSecondCounter   *perfCounter
-	bytesSentPerSecondCounter       *perfCounter
-	packetsReceivedDiscardedCounter *perfCounter
-	packetsReceivedErrorsCounter    *perfCounter
-	packetsOutboundDiscardedCounter *perfCounter
-	packetsOutboundErrorsCounter    *perfCounter
+	packetsReceivedPerSecondCounter perfCounter
+	packetsSentPerSecondCounter     perfCounter
+	bytesReceivedPerSecondCounter   perfCounter
+	bytesSentPerSecondCounter       perfCounter
+	packetsReceivedDiscardedCounter perfCounter
+	packetsReceivedErrorsCounter    perfCounter
+	packetsOutboundDiscardedCounter perfCounter
+	packetsOutboundErrorsCounter    perfCounter
 
 	mu           sync.RWMutex
 	adapterStats map[string]cadvisorapi.InterfaceStats

pkg/kubelet/winstats/network_stats_test.go

@@ -0,0 +1,176 @@
+//go:build windows
+// +build windows
+
+/*
+Copyright 2023 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 winstats
+
+import (
+	"errors"
+	"testing"
+
+	cadvisorapi "github.com/google/cadvisor/info/v1"
+	"github.com/stretchr/testify/assert"
+)
+
+const fakeAdapterName = "fake-adapter"
+
+type fakePerfCounterImpl struct {
+	// Returned name.
+	name string
+	// Returned value.
+	value uint64
+	// If the perfCounter should raise an error.
+	raiseError bool
+}
+
+func (p *fakePerfCounterImpl) getData() (uint64, error) {
+	if p.raiseError {
+		return 0, errors.New("Expected getData error.")
+	}
+	return p.value, nil
+}
+
+func (p *fakePerfCounterImpl) getDataList() (map[string]uint64, error) {
+	if p.raiseError {
+		return nil, errors.New("Expected getDataList error.")
+	}
+
+	data := make(map[string]uint64)
+	data[p.name] = p.value
+	return data, nil
+}
+
+func newFakedNetworkCounters(raiseError bool) *networkCounter {
+	counters := make([]*fakePerfCounterImpl, 8)
+	for i := 0; i < 8; i++ {
+		counters[i] = &fakePerfCounterImpl{
+			name:       fakeAdapterName,
+			value:      1,
+			raiseError: raiseError,
+		}
+	}
+	return &networkCounter{
+		packetsReceivedPerSecondCounter: counters[0],
+		packetsSentPerSecondCounter:     counters[1],
+		bytesReceivedPerSecondCounter:   counters[2],
+		bytesSentPerSecondCounter:       counters[3],
+		packetsReceivedDiscardedCounter: counters[4],
+		packetsReceivedErrorsCounter:    counters[5],
+		packetsOutboundDiscardedCounter: counters[6],
+		packetsOutboundErrorsCounter:    counters[7],
+		adapterStats:                    map[string]cadvisorapi.InterfaceStats{},
+	}
+}
+
+func TestNewNetworkCounters(t *testing.T) {
+	_, err := newNetworkCounters()
+	assert.NoError(t, err)
+}
+
+func TestNetworkGetData(t *testing.T) {
+	netCounter := newFakedNetworkCounters(false)
+
+	// Add a net adapter that no longer exists in the adapterStats cache. It will
+	// have to be cleaned up after processing the data.
+	netCounter.adapterStats["other-fake-adapter"] = cadvisorapi.InterfaceStats{}
+
+	data, err := netCounter.getData()
+	assert.NoError(t, err)
+
+	// Make sure that we only have data from a single net adapter.
+	expectedStats := cadvisorapi.InterfaceStats{
+		Name:      fakeAdapterName,
+		RxPackets: 1,
+		TxPackets: 1,
+		RxBytes:   1,
+		TxBytes:   1,
+		RxDropped: 1,
+		RxErrors:  1,
+		TxDropped: 1,
+		TxErrors:  1,
+	}
+	assert.Equal(t, []cadvisorapi.InterfaceStats{expectedStats}, data)
+
+	// The returned data is cumulative, so the resulting values should be double on a second call.
+	data, err = netCounter.getData()
+	assert.NoError(t, err)
+	expectedStats = cadvisorapi.InterfaceStats{
+		Name:      fakeAdapterName,
+		RxPackets: 2,
+		TxPackets: 2,
+		RxBytes:   2,
+		TxBytes:   2,
+		RxDropped: 1,
+		RxErrors:  1,
+		TxDropped: 1,
+		TxErrors:  1,
+	}
+	assert.Equal(t, []cadvisorapi.InterfaceStats{expectedStats}, data)
+}
+
+func TestNetworkGetDataFailures(t *testing.T) {
+	netCounter := newFakedNetworkCounters(true)
+
+	_, err := netCounter.getData()
+	expectedMsg := "Expected getDataList error."
+	if err == nil || err.Error() != expectedMsg {
+		t.Fatalf("expected error message `%s` but got `%v`", expectedMsg, err)
+	}
+
+	_, err = netCounter.getData()
+	netCounter.packetsReceivedPerSecondCounter.(*fakePerfCounterImpl).raiseError = false
+	if err == nil || err.Error() != expectedMsg {
+		t.Fatalf("expected error message `%s` but got `%v`", expectedMsg, err)
+	}
+
+	_, err = netCounter.getData()
+	netCounter.packetsSentPerSecondCounter.(*fakePerfCounterImpl).raiseError = false
+	if err == nil || err.Error() != expectedMsg {
+		t.Fatalf("expected error message `%s` but got `%v`", expectedMsg, err)
+	}
+
+	_, err = netCounter.getData()
+	netCounter.bytesReceivedPerSecondCounter.(*fakePerfCounterImpl).raiseError = false
+	if err == nil || err.Error() != expectedMsg {
+		t.Fatalf("expected error message `%s` but got `%v`", expectedMsg, err)
+	}
+
+	_, err = netCounter.getData()
+	netCounter.bytesSentPerSecondCounter.(*fakePerfCounterImpl).raiseError = false
+	if err == nil || err.Error() != expectedMsg {
+		t.Fatalf("expected error message `%s` but got `%v`", expectedMsg, err)
+	}
+
+	_, err = netCounter.getData()
+	netCounter.packetsReceivedDiscardedCounter.(*fakePerfCounterImpl).raiseError = false
+	if err == nil || err.Error() != expectedMsg {
+		t.Fatalf("expected error message `%s` but got `%v`", expectedMsg, err)
+	}
+
+	_, err = netCounter.getData()
+	netCounter.packetsReceivedErrorsCounter.(*fakePerfCounterImpl).raiseError = false
+	if err == nil || err.Error() != expectedMsg {
+		t.Fatalf("expected error message `%s` but got `%v`", expectedMsg, err)
+	}
+
+	_, err = netCounter.getData()
+	netCounter.packetsOutboundDiscardedCounter.(*fakePerfCounterImpl).raiseError = false
+	if err == nil || err.Error() != expectedMsg {
+		t.Fatalf("expected error message `%s` but got `%v`", expectedMsg, err)
+	}
+}

pkg/kubelet/winstats/perfcounter_nodestats.go

@@ -202,9 +202,9 @@ func (p *perfCounterNodeStatsClient) getNodeInfo() nodeInfo {
 	return p.nodeInfo
 }
 
-func (p *perfCounterNodeStatsClient) collectMetricsData(cpuCounter, memWorkingSetCounter, memCommittedBytesCounter *perfCounter, networkAdapterCounter *networkCounter) {
+func (p *perfCounterNodeStatsClient) collectMetricsData(cpuCounter, memWorkingSetCounter, memCommittedBytesCounter perfCounter, networkAdapterCounter *networkCounter) {
 	cpuValue, err := cpuCounter.getData()
-	cpuCores := runtime.NumCPU()
+	cpuCores := ProcessorCount()
 	if err != nil {
 		klog.ErrorS(err, "Unable to get cpu perf counter data")
 		return

pkg/kubelet/winstats/perfcounter_nodestats_test.go

@@ -0,0 +1,188 @@
+//go:build windows
+// +build windows
+
+/*
+Copyright 2023 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 winstats
+
+import (
+	"os"
+	"strconv"
+	"testing"
+	"time"
+
+	cadvisorapi "github.com/google/cadvisor/info/v1"
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/assert"
+	"k8s.io/apimachinery/pkg/util/wait"
+)
+
+func TestMonitoring(t *testing.T) {
+	counterClient, err := NewPerfCounterClient()
+	assert.NoError(t, err)
+
+	// assert that startMonitoring has been called. nodeInfo should be set.
+	assert.NotNil(t, counterClient.(*StatsClient).client.getNodeInfo())
+
+	// Wait until we get a non-zero node metrics.
+	if pollErr := wait.Poll(100*time.Millisecond, 5*perfCounterUpdatePeriod, func() (bool, error) {
+		metrics, _ := counterClient.(*StatsClient).client.getNodeMetrics()
+		if metrics.memoryPrivWorkingSetBytes != 0 {
+			return true, nil
+		}
+
+		return false, nil
+	}); pollErr != nil {
+		t.Fatalf("Encountered error: `%v'", pollErr)
+	}
+}
+
+func TestGetMachineInfo(t *testing.T) {
+	p := perfCounterNodeStatsClient{
+		nodeInfo: nodeInfo{
+			memoryPhysicalCapacityBytes: 100,
+		},
+	}
+
+	machineInfo, err := p.getMachineInfo()
+	assert.NoError(t, err)
+	assert.Equal(t, uint64(100), machineInfo.MemoryCapacity)
+	hostname, _ := os.Hostname()
+	assert.Equal(t, hostname, machineInfo.MachineID)
+
+	// Check if it's an UUID.
+	_, err = uuid.Parse(machineInfo.SystemUUID)
+	assert.NoError(t, err)
+
+	id, err := strconv.Atoi(machineInfo.BootID)
+	assert.NoError(t, err)
+	assert.NotZero(t, id)
+}
+
+func TestGetVersionInfo(t *testing.T) {
+	client := perfCounterNodeStatsClient{
+		nodeInfo: nodeInfo{
+			kernelVersion:  "foo",
+			osImageVersion: "lish",
+		},
+	}
+
+	info, _ := client.getVersionInfo()
+	expected := &cadvisorapi.VersionInfo{
+		KernelVersion:      "foo",
+		ContainerOsVersion: "lish",
+	}
+	assert.Equal(t, expected, info)
+}
+
+func TestCollectMetricsData(t *testing.T) {
+	p := perfCounterNodeStatsClient{}
+
+	cpuCounter := &fakePerfCounterImpl{
+		value:      1,
+		raiseError: true,
+	}
+	memWorkingSetCounter := &fakePerfCounterImpl{
+		value:      2,
+		raiseError: true,
+	}
+	memCommittedBytesCounter := &fakePerfCounterImpl{
+		value:      3,
+		raiseError: true,
+	}
+	networkAdapterCounter := newFakedNetworkCounters(true)
+
+	// Checking the error cases first.
+	p.collectMetricsData(cpuCounter, memWorkingSetCounter, memCommittedBytesCounter, networkAdapterCounter)
+	metrics, _ := p.getNodeMetrics()
+	expectedMetrics := nodeMetrics{}
+	assert.Equal(t, expectedMetrics, metrics)
+
+	cpuCounter.raiseError = false
+	p.collectMetricsData(cpuCounter, memWorkingSetCounter, memCommittedBytesCounter, networkAdapterCounter)
+	metrics, _ = p.getNodeMetrics()
+	assert.Equal(t, expectedMetrics, metrics)
+
+	memWorkingSetCounter.raiseError = false
+	p.collectMetricsData(cpuCounter, memWorkingSetCounter, memCommittedBytesCounter, networkAdapterCounter)
+	metrics, _ = p.getNodeMetrics()
+	assert.Equal(t, expectedMetrics, metrics)
+
+	memCommittedBytesCounter.raiseError = false
+	p.collectMetricsData(cpuCounter, memWorkingSetCounter, memCommittedBytesCounter, networkAdapterCounter)
+	metrics, _ = p.getNodeMetrics()
+	assert.Equal(t, expectedMetrics, metrics)
+
+	networkAdapterCounter = newFakedNetworkCounters(false)
+	p.collectMetricsData(cpuCounter, memWorkingSetCounter, memCommittedBytesCounter, networkAdapterCounter)
+	metrics, _ = p.getNodeMetrics()
+	expectedMetrics = nodeMetrics{
+		cpuUsageCoreNanoSeconds:   uint64(ProcessorCount()) * 1e7,
+		cpuUsageNanoCores:         0,
+		memoryPrivWorkingSetBytes: 2,
+		memoryCommittedBytes:      3,
+		interfaceStats:            networkAdapterCounter.listInterfaceStats(),
+		timeStamp:                 time.Now(),
+	}
+	assert.Equal(t, expectedMetrics, metrics)
+}
+
+func TestConvertCPUValue(t *testing.T) {
+	testCases := []struct {
+		cpuValue uint64
+		expected uint64
+	}{
+		{cpuValue: uint64(50), expected: uint64(2000000000)},
+		{cpuValue: uint64(0), expected: uint64(0)},
+		{cpuValue: uint64(100), expected: uint64(4000000000)},
+	}
+	var cpuCores = 4
+
+	for _, tc := range testCases {
+		p := perfCounterNodeStatsClient{}
+		newValue := p.convertCPUValue(cpuCores, tc.cpuValue)
+		assert.Equal(t, tc.expected, newValue)
+	}
+}
+
+func TestGetCPUUsageNanoCores(t *testing.T) {
+	testCases := []struct {
+		latestValue   uint64
+		previousValue uint64
+		expected      uint64
+	}{
+		{latestValue: uint64(0), previousValue: uint64(0), expected: uint64(0)},
+		{latestValue: uint64(2000000000), previousValue: uint64(0), expected: uint64(200000000)},
+		{latestValue: uint64(5000000000), previousValue: uint64(2000000000), expected: uint64(300000000)},
+	}
+
+	for _, tc := range testCases {
+		p := perfCounterNodeStatsClient{}
+		p.cpuUsageCoreNanoSecondsCache = cpuUsageCoreNanoSecondsCache{
+			latestValue:   tc.latestValue,
+			previousValue: tc.previousValue,
+		}
+		cpuUsageNanoCores := p.getCPUUsageNanoCores()
+		assert.Equal(t, tc.expected, cpuUsageNanoCores)
+	}
+}
+
+func testGetPhysicallyInstalledSystemMemoryBytes(t *testing.T) {
+	totalMemory, err := getPhysicallyInstalledSystemMemoryBytes()
+	assert.NoError(t, err)
+	assert.NotZero(t, totalMemory)
+}

pkg/kubelet/winstats/perfcounters.go

@@ -41,12 +41,17 @@ const (
 	defaultCachePeriod = 10 * time.Second
 )
 
-type perfCounter struct {
+type perfCounter interface {
+	getData() (uint64, error)
+	getDataList() (map[string]uint64, error)
+}
+
+type perfCounterImpl struct {
 	queryHandle   win_pdh.PDH_HQUERY
 	counterHandle win_pdh.PDH_HCOUNTER
 }
 
-func newPerfCounter(counter string) (*perfCounter, error) {
+func newPerfCounter(counter string) (perfCounter, error) {
 	var queryHandle win_pdh.PDH_HQUERY
 	var counterHandle win_pdh.PDH_HCOUNTER
 
@@ -65,35 +70,20 @@ func newPerfCounter(counter string) (*perfCounter, error) {
 		return nil, fmt.Errorf("unable to collect data from counter. Error code is %x", ret)
 	}
 
-	return &perfCounter{
+	return &perfCounterImpl{
 		queryHandle:   queryHandle,
 		counterHandle: counterHandle,
 	}, nil
 }
 
 // getData is used for getting data without * in counter name.
-func (p *perfCounter) getData() (uint64, error) {
-	ret := win_pdh.PdhCollectQueryData(p.queryHandle)
-	if ret != win_pdh.ERROR_SUCCESS {
-		return 0, fmt.Errorf("unable to collect data from counter. Error code is %x", ret)
-	}
-
-	var bufSize, bufCount uint32
-	var size = uint32(unsafe.Sizeof(win_pdh.PDH_FMT_COUNTERVALUE_ITEM_DOUBLE{}))
-	var emptyBuf [1]win_pdh.PDH_FMT_COUNTERVALUE_ITEM_DOUBLE // need at least 1 addressable null ptr.
-	var data uint64
-
-	ret = win_pdh.PdhGetFormattedCounterArrayDouble(p.counterHandle, &bufSize, &bufCount, &emptyBuf[0])
-	if ret != win_pdh.PDH_MORE_DATA {
-		return 0, fmt.Errorf("unable to collect data from counter. Error code is %x", ret)
-	}
-
-	filledBuf := make([]win_pdh.PDH_FMT_COUNTERVALUE_ITEM_DOUBLE, bufCount*size)
-	ret = win_pdh.PdhGetFormattedCounterArrayDouble(p.counterHandle, &bufSize, &bufCount, &filledBuf[0])
-	if ret != win_pdh.ERROR_SUCCESS {
-		return 0, fmt.Errorf("unable to collect data from counter. Error code is %x", ret)
+func (p *perfCounterImpl) getData() (uint64, error) {
+	filledBuf, bufCount, err := p.getQueriedData()
+	if err != nil {
+		return 0, err
 	}
 
+	var data uint64 = 0
 	for i := 0; i < int(bufCount); i++ {
 		c := filledBuf[i]
 		data = uint64(c.FmtValue.DoubleValue)
@@ -102,29 +92,14 @@ func (p *perfCounter) getData() (uint64, error) {
 	return data, nil
 }
 
-// getData is used for getting data with * in counter name.
-func (p *perfCounter) getDataList() (map[string]uint64, error) {
-	ret := win_pdh.PdhCollectQueryData(p.queryHandle)
-	if ret != win_pdh.ERROR_SUCCESS {
-		return nil, fmt.Errorf("unable to collect data from counter. Error code is %x", ret)
+// getDataList is used for getting data with * in counter name.
+func (p *perfCounterImpl) getDataList() (map[string]uint64, error) {
+	filledBuf, bufCount, err := p.getQueriedData()
+	if err != nil {
+		return nil, err
 	}
 
-	var bufSize, bufCount uint32
-	var size = uint32(unsafe.Sizeof(win_pdh.PDH_FMT_COUNTERVALUE_ITEM_DOUBLE{}))
-	var emptyBuf [1]win_pdh.PDH_FMT_COUNTERVALUE_ITEM_DOUBLE // need at least 1 addressable null ptr.
 	data := map[string]uint64{}
-
-	ret = win_pdh.PdhGetFormattedCounterArrayDouble(p.counterHandle, &bufSize, &bufCount, &emptyBuf[0])
-	if ret != win_pdh.PDH_MORE_DATA {
-		return nil, fmt.Errorf("unable to collect data from counter. Error code is %x", ret)
-	}
-
-	filledBuf := make([]win_pdh.PDH_FMT_COUNTERVALUE_ITEM_DOUBLE, bufCount*size)
-	ret = win_pdh.PdhGetFormattedCounterArrayDouble(p.counterHandle, &bufSize, &bufCount, &filledBuf[0])
-	if ret != win_pdh.ERROR_SUCCESS {
-		return nil, fmt.Errorf("unable to collect data from counter. Error code is %x", ret)
-	}
-
 	for i := 0; i < int(bufCount); i++ {
 		c := filledBuf[i]
 		value := uint64(c.FmtValue.DoubleValue)
@@ -134,3 +109,28 @@ func (p *perfCounter) getDataList() (map[string]uint64, error) {
 
 	return data, nil
 }
+
+// getQueriedData is used for getting data using the given query handle.
+func (p *perfCounterImpl) getQueriedData() ([]win_pdh.PDH_FMT_COUNTERVALUE_ITEM_DOUBLE, uint32, error) {
+	ret := win_pdh.PdhCollectQueryData(p.queryHandle)
+	if ret != win_pdh.ERROR_SUCCESS {
+		return nil, 0, fmt.Errorf("unable to collect data from counter. Error code is %x", ret)
+	}
+
+	var bufSize, bufCount uint32
+	var size = uint32(unsafe.Sizeof(win_pdh.PDH_FMT_COUNTERVALUE_ITEM_DOUBLE{}))
+	var emptyBuf [1]win_pdh.PDH_FMT_COUNTERVALUE_ITEM_DOUBLE // need at least 1 addressable null ptr.
+
+	ret = win_pdh.PdhGetFormattedCounterArrayDouble(p.counterHandle, &bufSize, &bufCount, &emptyBuf[0])
+	if ret != win_pdh.PDH_MORE_DATA {
+		return nil, 0, fmt.Errorf("unable to collect data from counter. Error code is %x", ret)
+	}
+
+	filledBuf := make([]win_pdh.PDH_FMT_COUNTERVALUE_ITEM_DOUBLE, bufCount*size)
+	ret = win_pdh.PdhGetFormattedCounterArrayDouble(p.counterHandle, &bufSize, &bufCount, &filledBuf[0])
+	if ret != win_pdh.ERROR_SUCCESS {
+		return nil, 0, fmt.Errorf("unable to collect data from counter. Error code is %x", ret)
+	}
+
+	return filledBuf, bufCount, nil
+}

pkg/kubelet/winstats/perfcounters_test.go

@@ -0,0 +1,136 @@
+//go:build windows
+// +build windows
+
+/*
+Copyright 2023 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 winstats
+
+import (
+	"testing"
+	"time"
+
+	"k8s.io/apimachinery/pkg/util/wait"
+)
+
+func TestPerfCounter(t *testing.T) {
+	testCases := map[string]struct {
+		counter        string
+		skipCheck      bool
+		expectErr      bool
+		expectedErrMsg string
+	}{
+		"CPU Query": {
+			counter: cpuQuery,
+		},
+		"Memory Prvate Working Set Query": {
+			counter: memoryPrivWorkingSetQuery,
+		},
+		"Memory Committed Bytes Query": {
+			counter: memoryCommittedBytesQuery,
+		},
+		"Net Adapter Packets Received/sec Query": {
+			counter:   packetsReceivedPerSecondQuery,
+			skipCheck: true,
+		},
+		"Net Adapter Packets Sent/sec Query": {
+			counter:   packetsSentPerSecondQuery,
+			skipCheck: true,
+		},
+		"Net Adapter Bytes Received/sec Query": {
+			counter:   bytesReceivedPerSecondQuery,
+			skipCheck: true,
+		},
+		"Net Adapter Bytes Sent/sec Query": {
+			counter:   bytesSentPerSecondQuery,
+			skipCheck: true,
+		},
+		"Net Adapter Packets Received Discarded Query": {
+			counter:   packetsReceivedDiscardedQuery,
+			skipCheck: true,
+		},
+		"Net Adapter Packets Received Errors Query": {
+			counter:   packetsReceivedErrorsQuery,
+			skipCheck: true,
+		},
+		"Net Adapter Packets Outbound Discarded Query": {
+			counter:   packetsOutboundDiscardedQuery,
+			skipCheck: true,
+		},
+		"Net Adapter Packets Outbound Errors Query": {
+			counter:   packetsOutboundErrorsQuery,
+			skipCheck: true,
+		},
+		"Invalid Query": {
+			counter:        "foo",
+			expectErr:      true,
+			expectedErrMsg: "unable to add process counter: foo. Error code is c0000bc0",
+		},
+	}
+
+	for name, tc := range testCases {
+		t.Run(name, func(t *testing.T) {
+			counter, err := newPerfCounter(tc.counter)
+			if tc.expectErr {
+				if err == nil || err.Error() != tc.expectedErrMsg {
+					t.Fatalf("expected error message `%s` but got `%v`", tc.expectedErrMsg, err)
+				}
+				return
+			}
+
+			// There are some counters that we can't expect to see any non-zero values, like the
+			// networking-related counters.
+			if tc.skipCheck {
+				return
+			}
+
+			// Wait until we get a non-zero perf counter data.
+			if pollErr := wait.Poll(100*time.Millisecond, 5*perfCounterUpdatePeriod, func() (bool, error) {
+				data, err := counter.getData()
+				if err != nil {
+					return false, err
+				}
+
+				if data != 0 {
+					return true, nil
+				}
+
+				return false, nil
+			}); pollErr != nil {
+				t.Fatalf("Encountered error: `%v'", pollErr)
+				return
+			}
+
+			// Check that we have at least one non-zero value in the data list.
+			if pollErr := wait.Poll(100*time.Millisecond, 5*perfCounterUpdatePeriod, func() (bool, error) {
+				dataList, err := counter.getDataList()
+				if err != nil {
+					return false, err
+				}
+
+				for _, value := range dataList {
+					if value != 0 {
+						return true, nil
+					}
+				}
+
+				return false, nil
+			}); pollErr != nil {
+				t.Fatalf("Encountered error: `%v'", pollErr)
+			}
+		})
+	}
+}

pkg/kubelet/winstats/winstats_test.go

@@ -20,6 +20,7 @@ limitations under the License.
 package winstats
 
 import (
+	"os"
 	"testing"
 	"time"
 
@@ -133,44 +134,24 @@ func TestWinVersionInfo(t *testing.T) {
 		KernelVersion: "v42"})
 }
 
-func TestConvertCPUValue(t *testing.T) {
-	testCases := []struct {
-		cpuValue uint64
-		expected uint64
-	}{
-		{cpuValue: uint64(50), expected: uint64(2000000000)},
-		{cpuValue: uint64(0), expected: uint64(0)},
-		{cpuValue: uint64(100), expected: uint64(4000000000)},
-	}
-	var cpuCores = 4
+func TestGetDirFsInfo(t *testing.T) {
+	c := getClient(t)
 
-	for _, tc := range testCases {
-		p := perfCounterNodeStatsClient{}
-		newValue := p.convertCPUValue(cpuCores, tc.cpuValue)
-		assert.Equal(t, tc.expected, newValue)
-	}
+	// Try with a non-existent path.
+	_, err := c.GetDirFsInfo("foo/lish")
+	expectedErrMsg := "The system cannot find the path specified."
+	if err == nil || err.Error() != expectedErrMsg {
+		t.Fatalf("expected error message `%s` but got `%v`", expectedErrMsg, err)
 	}
 
-func TestGetCPUUsageNanoCores(t *testing.T) {
-	testCases := []struct {
-		latestValue   uint64
-		previousValue uint64
-		expected      uint64
-	}{
-		{latestValue: uint64(0), previousValue: uint64(0), expected: uint64(0)},
-		{latestValue: uint64(2000000000), previousValue: uint64(0), expected: uint64(200000000)},
-		{latestValue: uint64(5000000000), previousValue: uint64(2000000000), expected: uint64(300000000)},
-	}
+	dir, err := os.MkdirTemp("", "fsinfo")
+	assert.NoError(t, err)
+	defer os.RemoveAll(dir)
 
-	for _, tc := range testCases {
-		p := perfCounterNodeStatsClient{}
-		p.cpuUsageCoreNanoSecondsCache = cpuUsageCoreNanoSecondsCache{
-			latestValue:   tc.latestValue,
-			previousValue: tc.previousValue,
-		}
-		cpuUsageNanoCores := p.getCPUUsageNanoCores()
-		assert.Equal(t, tc.expected, cpuUsageNanoCores)
-	}
+	fsInfo, err := c.GetDirFsInfo(dir)
+	assert.NoError(t, err)
+	assert.NotZero(t, fsInfo.Capacity)
+	assert.NotZero(t, fsInfo.Available)
 }
 
 func getClient(t *testing.T) Client {