/*
Copyright 2017 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 stats

import (
	"fmt"
	"testing"
	"time"

	cadvisorapiv1 "github.com/google/cadvisor/info/v1"
	cadvisorapiv2 "github.com/google/cadvisor/info/v2"
	fuzz "github.com/google/gofuzz"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"

	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/types"
	statsapi "k8s.io/kubernetes/pkg/kubelet/apis/stats/v1alpha1"
	cadvisortest "k8s.io/kubernetes/pkg/kubelet/cadvisor/testing"
	kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
	kubecontainertest "k8s.io/kubernetes/pkg/kubelet/container/testing"
	kubepodtest "k8s.io/kubernetes/pkg/kubelet/pod/testing"
	serverstats "k8s.io/kubernetes/pkg/kubelet/server/stats"
	kubetypes "k8s.io/kubernetes/pkg/kubelet/types"
)

const (
	// Offsets from seed value in generated container stats.
	offsetCPUUsageCores = iota
	offsetCPUUsageCoreSeconds
	offsetMemPageFaults
	offsetMemMajorPageFaults
	offsetMemUsageBytes
	offsetMemRSSBytes
	offsetMemWorkingSetBytes
	offsetNetRxBytes
	offsetNetRxErrors
	offsetNetTxBytes
	offsetNetTxErrors
	offsetFsCapacity
	offsetFsAvailable
	offsetFsUsage
	offsetFsInodes
	offsetFsInodesFree
	offsetFsTotalUsageBytes
	offsetFsBaseUsageBytes
	offsetFsInodeUsage
)

var (
	timestamp    = time.Now()
	creationTime = timestamp.Add(-5 * time.Minute)
)

func TestGetCgroupStats(t *testing.T) {
	const (
		cgroupName        = "test-cgroup-name"
		containerInfoSeed = 1000
		updateStats       = false
	)
	var (
		mockCadvisor     = new(cadvisortest.Mock)
		mockPodManager   = new(kubepodtest.MockManager)
		mockRuntimeCache = new(kubecontainertest.MockRuntimeCache)

		assert  = assert.New(t)
		options = cadvisorapiv2.RequestOptions{IdType: cadvisorapiv2.TypeName, Count: 2, Recursive: false}

		containerInfo    = getTestContainerInfo(containerInfoSeed, "test-pod", "test-ns", "test-container")
		containerInfoMap = map[string]cadvisorapiv2.ContainerInfo{cgroupName: containerInfo}
	)

	mockCadvisor.On("ContainerInfoV2", cgroupName, options).Return(containerInfoMap, nil)

	provider := newStatsProvider(mockCadvisor, mockPodManager, mockRuntimeCache, fakeContainerStatsProvider{})
	cs, ns, err := provider.GetCgroupStats(cgroupName, updateStats)
	assert.NoError(err)

	checkCPUStats(t, "", containerInfoSeed, cs.CPU)
	checkMemoryStats(t, "", containerInfoSeed, containerInfo, cs.Memory)
	checkNetworkStats(t, "", containerInfoSeed, ns)

	assert.Equal(cgroupName, cs.Name)
	assert.Equal(metav1.NewTime(containerInfo.Spec.CreationTime), cs.StartTime)

	mockCadvisor.AssertExpectations(t)
}

func TestRootFsStats(t *testing.T) {
	const (
		rootFsInfoSeed    = 1000
		containerInfoSeed = 2000
	)
	var (
		mockCadvisor     = new(cadvisortest.Mock)
		mockPodManager   = new(kubepodtest.MockManager)
		mockRuntimeCache = new(kubecontainertest.MockRuntimeCache)

		assert  = assert.New(t)
		options = cadvisorapiv2.RequestOptions{IdType: cadvisorapiv2.TypeName, Count: 2, Recursive: false}

		rootFsInfo       = getTestFsInfo(rootFsInfoSeed)
		containerInfo    = getTestContainerInfo(containerInfoSeed, "test-pod", "test-ns", "test-container")
		containerInfoMap = map[string]cadvisorapiv2.ContainerInfo{"/": containerInfo}
	)

	mockCadvisor.
		On("RootFsInfo").Return(rootFsInfo, nil).
		On("ContainerInfoV2", "/", options).Return(containerInfoMap, nil)

	provider := newStatsProvider(mockCadvisor, mockPodManager, mockRuntimeCache, fakeContainerStatsProvider{})
	stats, err := provider.RootFsStats()
	assert.NoError(err)

	checkFsStats(t, "", rootFsInfoSeed, stats)

	assert.Equal(metav1.NewTime(containerInfo.Stats[0].Timestamp), stats.Time)
	assert.Equal(rootFsInfo.Usage, *stats.UsedBytes)
	assert.Equal(*rootFsInfo.Inodes-*rootFsInfo.InodesFree, *stats.InodesUsed)

	mockCadvisor.AssertExpectations(t)
}

func TestGetContainerInfo(t *testing.T) {
	cadvisorAPIFailure := fmt.Errorf("cAdvisor failure")
	runtimeError := fmt.Errorf("List containers error")
	tests := []struct {
		name                      string
		containerID               string
		containerPath             string
		cadvisorContainerInfo     cadvisorapiv1.ContainerInfo
		runtimeError              error
		podList                   []*kubecontainer.Pod
		requestedPodFullName      string
		requestedPodUID           types.UID
		requestedContainerName    string
		expectDockerContainerCall bool
		mockError                 error
		expectedError             error
		expectStats               bool
	}{
		{
			name:          "get container info",
			containerID:   "ab2cdf",
			containerPath: "/docker/ab2cdf",
			cadvisorContainerInfo: cadvisorapiv1.ContainerInfo{
				ContainerReference: cadvisorapiv1.ContainerReference{
					Name: "/docker/ab2cdf",
				},
			},
			runtimeError: nil,
			podList: []*kubecontainer.Pod{
				{
					ID:        "12345678",
					Name:      "qux",
					Namespace: "ns",
					Containers: []*kubecontainer.Container{
						{
							Name: "foo",
							ID:   kubecontainer.ContainerID{Type: "test", ID: "ab2cdf"},
						},
					},
				},
			},
			requestedPodFullName:      "qux_ns",
			requestedPodUID:           "",
			requestedContainerName:    "foo",
			expectDockerContainerCall: true,
			mockError:                 nil,
			expectedError:             nil,
			expectStats:               true,
		},
		{
			name:                  "get container info when cadvisor failed",
			containerID:           "ab2cdf",
			containerPath:         "/docker/ab2cdf",
			cadvisorContainerInfo: cadvisorapiv1.ContainerInfo{},
			runtimeError:          nil,
			podList: []*kubecontainer.Pod{
				{
					ID:        "uuid",
					Name:      "qux",
					Namespace: "ns",
					Containers: []*kubecontainer.Container{
						{
							Name: "foo",
							ID:   kubecontainer.ContainerID{Type: "test", ID: "ab2cdf"},
						},
					},
				},
			},
			requestedPodFullName:      "qux_ns",
			requestedPodUID:           "uuid",
			requestedContainerName:    "foo",
			expectDockerContainerCall: true,
			mockError:                 cadvisorAPIFailure,
			expectedError:             cadvisorAPIFailure,
			expectStats:               false,
		},
		{
			name:                      "get container info on non-existent container",
			containerID:               "",
			containerPath:             "",
			cadvisorContainerInfo:     cadvisorapiv1.ContainerInfo{},
			runtimeError:              nil,
			podList:                   []*kubecontainer.Pod{},
			requestedPodFullName:      "qux",
			requestedPodUID:           "",
			requestedContainerName:    "foo",
			expectDockerContainerCall: false,
			mockError:                 nil,
			expectedError:             kubecontainer.ErrContainerNotFound,
			expectStats:               false,
		},
		{
			name:                   "get container info when container runtime failed",
			containerID:            "",
			containerPath:          "",
			cadvisorContainerInfo:  cadvisorapiv1.ContainerInfo{},
			runtimeError:           runtimeError,
			podList:                []*kubecontainer.Pod{},
			requestedPodFullName:   "qux",
			requestedPodUID:        "",
			requestedContainerName: "foo",
			mockError:              nil,
			expectedError:          runtimeError,
			expectStats:            false,
		},
		{
			name:                   "get container info with no containers",
			containerID:            "",
			containerPath:          "",
			cadvisorContainerInfo:  cadvisorapiv1.ContainerInfo{},
			runtimeError:           nil,
			podList:                []*kubecontainer.Pod{},
			requestedPodFullName:   "qux_ns",
			requestedPodUID:        "",
			requestedContainerName: "foo",
			mockError:              nil,
			expectedError:          kubecontainer.ErrContainerNotFound,
			expectStats:            false,
		},
		{
			name:                  "get container info with no matching containers",
			containerID:           "",
			containerPath:         "",
			cadvisorContainerInfo: cadvisorapiv1.ContainerInfo{},
			runtimeError:          nil,
			podList: []*kubecontainer.Pod{
				{
					ID:        "12345678",
					Name:      "qux",
					Namespace: "ns",
					Containers: []*kubecontainer.Container{
						{
							Name: "bar",
							ID:   kubecontainer.ContainerID{Type: "test", ID: "fakeID"},
						},
					},
				},
			},
			requestedPodFullName:   "qux_ns",
			requestedPodUID:        "",
			requestedContainerName: "foo",
			mockError:              nil,
			expectedError:          kubecontainer.ErrContainerNotFound,
			expectStats:            false,
		},
	}

	for _, tc := range tests {
		var (
			mockCadvisor     = new(cadvisortest.Mock)
			mockPodManager   = new(kubepodtest.MockManager)
			mockRuntimeCache = new(kubecontainertest.MockRuntimeCache)

			cadvisorReq = &cadvisorapiv1.ContainerInfoRequest{}
		)

		mockPodManager.On("TranslatePodUID", tc.requestedPodUID).Return(kubetypes.ResolvedPodUID(tc.requestedPodUID))
		mockRuntimeCache.On("GetPods").Return(tc.podList, tc.runtimeError)
		if tc.expectDockerContainerCall {
			mockCadvisor.On("DockerContainer", tc.containerID, cadvisorReq).Return(tc.cadvisorContainerInfo, tc.mockError)
		}

		provider := newStatsProvider(mockCadvisor, mockPodManager, mockRuntimeCache, fakeContainerStatsProvider{})
		stats, err := provider.GetContainerInfo(tc.requestedPodFullName, tc.requestedPodUID, tc.requestedContainerName, cadvisorReq)
		assert.Equal(t, tc.expectedError, err)

		if tc.expectStats {
			require.NotNil(t, stats)
		}
		mockCadvisor.AssertExpectations(t)
	}
}

func TestGetRawContainerInfoRoot(t *testing.T) {
	var (
		mockCadvisor     = new(cadvisortest.Mock)
		mockPodManager   = new(kubepodtest.MockManager)
		mockRuntimeCache = new(kubecontainertest.MockRuntimeCache)

		cadvisorReq   = &cadvisorapiv1.ContainerInfoRequest{}
		containerPath = "/"
		containerInfo = &cadvisorapiv1.ContainerInfo{
			ContainerReference: cadvisorapiv1.ContainerReference{
				Name: containerPath,
			},
		}
	)

	mockCadvisor.On("ContainerInfo", containerPath, cadvisorReq).Return(containerInfo, nil)

	provider := newStatsProvider(mockCadvisor, mockPodManager, mockRuntimeCache, fakeContainerStatsProvider{})
	_, err := provider.GetRawContainerInfo(containerPath, cadvisorReq, false)
	assert.NoError(t, err)
	mockCadvisor.AssertExpectations(t)
}

func TestGetRawContainerInfoSubcontainers(t *testing.T) {
	var (
		mockCadvisor     = new(cadvisortest.Mock)
		mockPodManager   = new(kubepodtest.MockManager)
		mockRuntimeCache = new(kubecontainertest.MockRuntimeCache)

		cadvisorReq   = &cadvisorapiv1.ContainerInfoRequest{}
		containerPath = "/kubelet"
		containerInfo = map[string]*cadvisorapiv1.ContainerInfo{
			containerPath: {
				ContainerReference: cadvisorapiv1.ContainerReference{
					Name: containerPath,
				},
			},
			"/kubelet/sub": {
				ContainerReference: cadvisorapiv1.ContainerReference{
					Name: "/kubelet/sub",
				},
			},
		}
	)

	mockCadvisor.On("SubcontainerInfo", containerPath, cadvisorReq).Return(containerInfo, nil)

	provider := newStatsProvider(mockCadvisor, mockPodManager, mockRuntimeCache, fakeContainerStatsProvider{})
	result, err := provider.GetRawContainerInfo(containerPath, cadvisorReq, true)
	assert.NoError(t, err)
	assert.Len(t, result, 2)
	mockCadvisor.AssertExpectations(t)
}

func TestHasDedicatedImageFs(t *testing.T) {
	for desc, test := range map[string]struct {
		rootfsDevice  string
		imagefsDevice string
		dedicated     bool
	}{
		"dedicated device for image filesystem": {
			rootfsDevice:  "root/device",
			imagefsDevice: "image/device",
			dedicated:     true,
		},
		"shared device for image filesystem": {
			rootfsDevice:  "share/device",
			imagefsDevice: "share/device",
			dedicated:     false,
		},
	} {
		t.Logf("TestCase %q", desc)
		var (
			mockCadvisor     = new(cadvisortest.Mock)
			mockPodManager   = new(kubepodtest.MockManager)
			mockRuntimeCache = new(kubecontainertest.MockRuntimeCache)
		)
		mockCadvisor.On("RootFsInfo").Return(cadvisorapiv2.FsInfo{Device: test.rootfsDevice}, nil)

		provider := newStatsProvider(mockCadvisor, mockPodManager, mockRuntimeCache, fakeContainerStatsProvider{
			device: test.imagefsDevice,
		})
		dedicated, err := provider.HasDedicatedImageFs()
		assert.NoError(t, err)
		assert.Equal(t, test.dedicated, dedicated)
		mockCadvisor.AssertExpectations(t)
	}
}

func getTerminatedContainerInfo(seed int, podName string, podNamespace string, containerName string) cadvisorapiv2.ContainerInfo {
	cinfo := getTestContainerInfo(seed, podName, podNamespace, containerName)
	cinfo.Stats[0].Memory.RSS = 0
	cinfo.Stats[0].CpuInst.Usage.Total = 0
	return cinfo
}

func getTestContainerInfo(seed int, podName string, podNamespace string, containerName string) cadvisorapiv2.ContainerInfo {
	labels := map[string]string{}
	if podName != "" {
		labels = map[string]string{
			"io.kubernetes.pod.name":       podName,
			"io.kubernetes.pod.uid":        "UID" + podName,
			"io.kubernetes.pod.namespace":  podNamespace,
			"io.kubernetes.container.name": containerName,
		}
	}
	// by default, kernel will set memory.limit_in_bytes to 1 << 63 if not bounded
	unlimitedMemory := uint64(1 << 63)
	spec := cadvisorapiv2.ContainerSpec{
		CreationTime: testTime(creationTime, seed),
		HasCpu:       true,
		HasMemory:    true,
		HasNetwork:   true,
		Labels:       labels,
		Memory: cadvisorapiv2.MemorySpec{
			Limit: unlimitedMemory,
		},
		CustomMetrics: generateCustomMetricSpec(),
	}

	totalUsageBytes := uint64(seed + offsetFsTotalUsageBytes)
	baseUsageBytes := uint64(seed + offsetFsBaseUsageBytes)
	inodeUsage := uint64(seed + offsetFsInodeUsage)

	stats := cadvisorapiv2.ContainerStats{
		Timestamp: testTime(timestamp, seed),
		Cpu:       &cadvisorapiv1.CpuStats{},
		CpuInst:   &cadvisorapiv2.CpuInstStats{},
		Memory: &cadvisorapiv1.MemoryStats{
			Usage:      uint64(seed + offsetMemUsageBytes),
			WorkingSet: uint64(seed + offsetMemWorkingSetBytes),
			RSS:        uint64(seed + offsetMemRSSBytes),
			ContainerData: cadvisorapiv1.MemoryStatsMemoryData{
				Pgfault:    uint64(seed + offsetMemPageFaults),
				Pgmajfault: uint64(seed + offsetMemMajorPageFaults),
			},
		},
		Network: &cadvisorapiv2.NetworkStats{
			Interfaces: []cadvisorapiv1.InterfaceStats{{
				Name:     "eth0",
				RxBytes:  uint64(seed + offsetNetRxBytes),
				RxErrors: uint64(seed + offsetNetRxErrors),
				TxBytes:  uint64(seed + offsetNetTxBytes),
				TxErrors: uint64(seed + offsetNetTxErrors),
			}, {
				Name:     "cbr0",
				RxBytes:  100,
				RxErrors: 100,
				TxBytes:  100,
				TxErrors: 100,
			}},
		},
		CustomMetrics: generateCustomMetrics(spec.CustomMetrics),
		Filesystem: &cadvisorapiv2.FilesystemStats{
			TotalUsageBytes: &totalUsageBytes,
			BaseUsageBytes:  &baseUsageBytes,
			InodeUsage:      &inodeUsage,
		},
	}
	stats.Cpu.Usage.Total = uint64(seed + offsetCPUUsageCoreSeconds)
	stats.CpuInst.Usage.Total = uint64(seed + offsetCPUUsageCores)
	return cadvisorapiv2.ContainerInfo{
		Spec:  spec,
		Stats: []*cadvisorapiv2.ContainerStats{&stats},
	}
}

func getTestFsInfo(seed int) cadvisorapiv2.FsInfo {
	var (
		inodes     = uint64(seed + offsetFsInodes)
		inodesFree = uint64(seed + offsetFsInodesFree)
	)
	return cadvisorapiv2.FsInfo{
		Timestamp:  time.Now(),
		Device:     "test-device",
		Mountpoint: "test-mount-point",
		Capacity:   uint64(seed + offsetFsCapacity),
		Available:  uint64(seed + offsetFsAvailable),
		Usage:      uint64(seed + offsetFsUsage),
		Inodes:     &inodes,
		InodesFree: &inodesFree,
	}
}

func getPodVolumeStats(seed int, volumeName string) statsapi.VolumeStats {
	availableBytes := uint64(seed + offsetFsAvailable)
	capacityBytes := uint64(seed + offsetFsCapacity)
	usedBytes := uint64(seed + offsetFsUsage)
	inodes := uint64(seed + offsetFsInodes)
	inodesFree := uint64(seed + offsetFsInodesFree)
	inodesUsed := uint64(seed + offsetFsInodeUsage)
	fsStats := statsapi.FsStats{
		Time:           metav1.NewTime(time.Now()),
		AvailableBytes: &availableBytes,
		CapacityBytes:  &capacityBytes,
		UsedBytes:      &usedBytes,
		Inodes:         &inodes,
		InodesFree:     &inodesFree,
		InodesUsed:     &inodesUsed,
	}
	return statsapi.VolumeStats{
		FsStats: fsStats,
		Name:    volumeName,
	}
}

func generateCustomMetricSpec() []cadvisorapiv1.MetricSpec {
	f := fuzz.New().NilChance(0).Funcs(
		func(e *cadvisorapiv1.MetricSpec, c fuzz.Continue) {
			c.Fuzz(&e.Name)
			switch c.Intn(3) {
			case 0:
				e.Type = cadvisorapiv1.MetricGauge
			case 1:
				e.Type = cadvisorapiv1.MetricCumulative
			case 2:
				e.Type = cadvisorapiv1.MetricDelta
			}
			switch c.Intn(2) {
			case 0:
				e.Format = cadvisorapiv1.IntType
			case 1:
				e.Format = cadvisorapiv1.FloatType
			}
			c.Fuzz(&e.Units)
		})
	var ret []cadvisorapiv1.MetricSpec
	f.Fuzz(&ret)
	return ret
}

func generateCustomMetrics(spec []cadvisorapiv1.MetricSpec) map[string][]cadvisorapiv1.MetricVal {
	ret := map[string][]cadvisorapiv1.MetricVal{}
	for _, metricSpec := range spec {
		f := fuzz.New().NilChance(0).Funcs(
			func(e *cadvisorapiv1.MetricVal, c fuzz.Continue) {
				switch metricSpec.Format {
				case cadvisorapiv1.IntType:
					c.Fuzz(&e.IntValue)
				case cadvisorapiv1.FloatType:
					c.Fuzz(&e.FloatValue)
				}
			})

		var metrics []cadvisorapiv1.MetricVal
		f.Fuzz(&metrics)
		ret[metricSpec.Name] = metrics
	}
	return ret
}

func testTime(base time.Time, seed int) time.Time {
	return base.Add(time.Duration(seed) * time.Second)
}

func checkNetworkStats(t *testing.T, label string, seed int, stats *statsapi.NetworkStats) {
	assert.NotNil(t, stats)
	assert.EqualValues(t, testTime(timestamp, seed).Unix(), stats.Time.Time.Unix(), label+".Net.Time")
	assert.EqualValues(t, "eth0", stats.Name, "default interface name is not eth0")
	assert.EqualValues(t, seed+offsetNetRxBytes, *stats.RxBytes, label+".Net.RxBytes")
	assert.EqualValues(t, seed+offsetNetRxErrors, *stats.RxErrors, label+".Net.RxErrors")
	assert.EqualValues(t, seed+offsetNetTxBytes, *stats.TxBytes, label+".Net.TxBytes")
	assert.EqualValues(t, seed+offsetNetTxErrors, *stats.TxErrors, label+".Net.TxErrors")

	assert.EqualValues(t, 2, len(stats.Interfaces), "network interfaces should contain 2 elements")

	assert.EqualValues(t, "eth0", stats.Interfaces[0].Name, "default interface name is ont eth0")
	assert.EqualValues(t, seed+offsetNetRxBytes, *stats.Interfaces[0].RxBytes, label+".Net.TxErrors")
	assert.EqualValues(t, seed+offsetNetRxErrors, *stats.Interfaces[0].RxErrors, label+".Net.TxErrors")
	assert.EqualValues(t, seed+offsetNetTxBytes, *stats.Interfaces[0].TxBytes, label+".Net.TxErrors")
	assert.EqualValues(t, seed+offsetNetTxErrors, *stats.Interfaces[0].TxErrors, label+".Net.TxErrors")

	assert.EqualValues(t, "cbr0", stats.Interfaces[1].Name, "cbr0 interface name is ont cbr0")
	assert.EqualValues(t, 100, *stats.Interfaces[1].RxBytes, label+".Net.TxErrors")
	assert.EqualValues(t, 100, *stats.Interfaces[1].RxErrors, label+".Net.TxErrors")
	assert.EqualValues(t, 100, *stats.Interfaces[1].TxBytes, label+".Net.TxErrors")
	assert.EqualValues(t, 100, *stats.Interfaces[1].TxErrors, label+".Net.TxErrors")

}

func checkCPUStats(t *testing.T, label string, seed int, stats *statsapi.CPUStats) {
	assert.EqualValues(t, testTime(timestamp, seed).Unix(), stats.Time.Time.Unix(), label+".CPU.Time")
	assert.EqualValues(t, seed+offsetCPUUsageCores, *stats.UsageNanoCores, label+".CPU.UsageCores")
	assert.EqualValues(t, seed+offsetCPUUsageCoreSeconds, *stats.UsageCoreNanoSeconds, label+".CPU.UsageCoreSeconds")
}

func checkMemoryStats(t *testing.T, label string, seed int, info cadvisorapiv2.ContainerInfo, stats *statsapi.MemoryStats) {
	assert.EqualValues(t, testTime(timestamp, seed).Unix(), stats.Time.Time.Unix(), label+".Mem.Time")
	assert.EqualValues(t, seed+offsetMemUsageBytes, *stats.UsageBytes, label+".Mem.UsageBytes")
	assert.EqualValues(t, seed+offsetMemWorkingSetBytes, *stats.WorkingSetBytes, label+".Mem.WorkingSetBytes")
	assert.EqualValues(t, seed+offsetMemRSSBytes, *stats.RSSBytes, label+".Mem.RSSBytes")
	assert.EqualValues(t, seed+offsetMemPageFaults, *stats.PageFaults, label+".Mem.PageFaults")
	assert.EqualValues(t, seed+offsetMemMajorPageFaults, *stats.MajorPageFaults, label+".Mem.MajorPageFaults")
	if !info.Spec.HasMemory || isMemoryUnlimited(info.Spec.Memory.Limit) {
		assert.Nil(t, stats.AvailableBytes, label+".Mem.AvailableBytes")
	} else {
		expected := info.Spec.Memory.Limit - *stats.WorkingSetBytes
		assert.EqualValues(t, expected, *stats.AvailableBytes, label+".Mem.AvailableBytes")
	}
}

func checkFsStats(t *testing.T, label string, seed int, stats *statsapi.FsStats) {
	assert.EqualValues(t, seed+offsetFsCapacity, *stats.CapacityBytes, label+".CapacityBytes")
	assert.EqualValues(t, seed+offsetFsAvailable, *stats.AvailableBytes, label+".AvailableBytes")
	assert.EqualValues(t, seed+offsetFsInodes, *stats.Inodes, label+".Inodes")
	assert.EqualValues(t, seed+offsetFsInodesFree, *stats.InodesFree, label+".InodesFree")
}

func checkEphemeralStats(t *testing.T, label string, containerSeeds []int, volumeSeeds []int, stats *statsapi.FsStats) {
	var usedBytes, inodeUsage int
	for _, cseed := range containerSeeds {
		usedBytes = usedBytes + cseed + offsetFsTotalUsageBytes
		inodeUsage += cseed + offsetFsInodeUsage
	}
	for _, vseed := range volumeSeeds {
		usedBytes = usedBytes + vseed + offsetFsUsage
		inodeUsage += vseed + offsetFsInodeUsage
	}
	assert.EqualValues(t, usedBytes, int(*stats.UsedBytes), label+".UsedBytes")
	assert.EqualValues(t, inodeUsage, int(*stats.InodesUsed), label+".InodesUsed")
}

type fakeResourceAnalyzer struct {
	podVolumeStats serverstats.PodVolumeStats
}

func (o *fakeResourceAnalyzer) Start()                              {}
func (o *fakeResourceAnalyzer) Get(bool) (*statsapi.Summary, error) { return nil, nil }
func (o *fakeResourceAnalyzer) GetPodVolumeStats(uid types.UID) (serverstats.PodVolumeStats, bool) {
	return o.podVolumeStats, true
}

type fakeContainerStatsProvider struct {
	device string
}

func (p fakeContainerStatsProvider) ListPodStats() ([]statsapi.PodStats, error) {
	return nil, fmt.Errorf("not implemented")
}
func (p fakeContainerStatsProvider) ImageFsStats() (*statsapi.FsStats, error) {
	return nil, fmt.Errorf("not implemented")
}

func (p fakeContainerStatsProvider) ImageFsDevice() (string, error) {
	return p.device, nil
}
