k3s/test/e2e_node/eviction_test.go

/*
Copyright 2016 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 e2e_node

import (
	"fmt"
	"path/filepath"
	"time"

	"k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/api/resource"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	nodeutil "k8s.io/kubernetes/pkg/api/v1/node"
	"k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig"
	stats "k8s.io/kubernetes/pkg/kubelet/apis/stats/v1alpha1"
	"k8s.io/kubernetes/pkg/kubelet/cm"
	kubeletmetrics "k8s.io/kubernetes/pkg/kubelet/metrics"
	"k8s.io/kubernetes/test/e2e/framework"

	. "github.com/onsi/ginkgo"
	. "github.com/onsi/gomega"
)

// Eviction Policy is described here:
// https://github.com/kubernetes/community/blob/master/contributors/design-proposals/kubelet-eviction.md

const (
	postTestConditionMonitoringPeriod = 1 * time.Minute
	evictionPollInterval              = 2 * time.Second
	pressureDissapearTimeout          = 1 * time.Minute
	longPodDeletionTimeout            = 10 * time.Minute
	// pressure conditions often surface after evictions because the kubelet only updates
	// node conditions periodically.
	// we wait this period after evictions to make sure that we wait out this delay
	pressureDelay  = 20 * time.Second
	testContextFmt = "when we run containers that should cause %s"
	noPressure     = v1.NodeConditionType("NoPressure")
)

// InodeEviction tests that the node responds to node disk pressure by evicting only responsible pods.
// Node disk pressure is induced by consuming all inodes on the node.
var _ = framework.KubeDescribe("InodeEviction [Slow] [Serial] [Disruptive] [Flaky]", func() {
	f := framework.NewDefaultFramework("inode-eviction-test")
	expectedNodeCondition := v1.NodeDiskPressure
	pressureTimeout := 15 * time.Minute
	inodesConsumed := uint64(200000)
	Context(fmt.Sprintf(testContextFmt, expectedNodeCondition), func() {
		tempSetCurrentKubeletConfig(f, func(initialConfig *kubeletconfig.KubeletConfiguration) {
			// Set the eviction threshold to inodesFree - inodesConsumed, so that using inodesConsumed causes an eviction.
			summary := eventuallyGetSummary()
			inodesFree := *summary.Node.Fs.InodesFree
			if inodesFree <= inodesConsumed {
				framework.Skipf("Too few inodes free on the host for the InodeEviction test to run")
			}
			initialConfig.EvictionHard = fmt.Sprintf("nodefs.inodesFree<%d", inodesFree-inodesConsumed)
			initialConfig.EvictionMinimumReclaim = ""
		})
		runEvictionTest(f, pressureTimeout, expectedNodeCondition, logInodeMetrics, []podEvictSpec{
			{
				evictionPriority: 1,
				pod:              inodeConsumingPod("container-inode-hog", nil),
			},
			{
				evictionPriority: 1,
				pod:              inodeConsumingPod("volume-inode-hog", &v1.VolumeSource{EmptyDir: &v1.EmptyDirVolumeSource{}}),
			},
			{
				evictionPriority: 0,
				pod:              innocentPod(),
			},
		})
	})
})

// MemoryAllocatableEviction tests that the node responds to node memory pressure by evicting only responsible pods.
// Node memory pressure is only encountered because we reserve the majority of the node's capacity via kube-reserved.
var _ = framework.KubeDescribe("MemoryAllocatableEviction [Slow] [Serial] [Disruptive] [Flaky]", func() {
	f := framework.NewDefaultFramework("memory-allocatable-eviction-test")
	expectedNodeCondition := v1.NodeMemoryPressure
	pressureTimeout := 10 * time.Minute
	Context(fmt.Sprintf(testContextFmt, expectedNodeCondition), func() {
		tempSetCurrentKubeletConfig(f, func(initialConfig *kubeletconfig.KubeletConfiguration) {
			// Set large system and kube reserved values to trigger allocatable thresholds far before hard eviction thresholds.
			kubeReserved := getNodeCPUAndMemoryCapacity(f)[v1.ResourceMemory]
			// The default hard eviction threshold is 250Mb, so Allocatable = Capacity - Reserved - 250Mb
			// We want Allocatable = 50Mb, so set Reserved = Capacity - Allocatable - 250Mb = Capacity - 300Mb
			kubeReserved.Sub(resource.MustParse("300Mi"))
			initialConfig.KubeReserved = kubeletconfig.ConfigurationMap(map[string]string{string(v1.ResourceMemory): kubeReserved.String()})
			initialConfig.EnforceNodeAllocatable = []string{cm.NodeAllocatableEnforcementKey}
			initialConfig.ExperimentalNodeAllocatableIgnoreEvictionThreshold = false
			initialConfig.CgroupsPerQOS = true
		})
		runEvictionTest(f, pressureTimeout, expectedNodeCondition, logMemoryMetrics, []podEvictSpec{
			{
				evictionPriority: 1,
				pod:              getMemhogPod("memory-hog-pod", "memory-hog", v1.ResourceRequirements{}),
			},
			{
				evictionPriority: 0,
				pod:              innocentPod(),
			},
		})
	})
})

// LocalStorageAllocatableEviction tests that the node responds to node disk pressure by evicting only responsible pods.
// Node disk pressure is only encountered because we reserve the majority of the node's capacity via kube-reserved.
var _ = framework.KubeDescribe("LocalStorageAllocatableEviction [Slow] [Serial] [Disruptive] [Flaky]", func() {
	f := framework.NewDefaultFramework("localstorageallocatable-eviction-test")
	pressureTimeout := 10 * time.Minute
	expectedNodeCondition := v1.NodeDiskPressure
	Context(fmt.Sprintf(testContextFmt, expectedNodeCondition), func() {
		// Set up --kube-reserved for scratch storage
		tempSetCurrentKubeletConfig(f, func(initialConfig *kubeletconfig.KubeletConfiguration) {
			diskConsumed := uint64(200000000) // At least 200 Mb for pods to consume
			summary := eventuallyGetSummary()
			availableBytes := *(summary.Node.Fs.AvailableBytes)
			initialConfig.KubeReserved = kubeletconfig.ConfigurationMap(map[string]string{string(v1.ResourceEphemeralStorage): fmt.Sprintf("%d", availableBytes-diskConsumed)})
			initialConfig.EnforceNodeAllocatable = []string{cm.NodeAllocatableEnforcementKey}
			initialConfig.CgroupsPerQOS = true
			initialConfig.ExperimentalNodeAllocatableIgnoreEvictionThreshold = false
			if initialConfig.FeatureGates != "" {
				initialConfig.FeatureGates += ","
			}
			initialConfig.FeatureGates += "LocalStorageCapacityIsolation=true"
			// set evictionHard to be very small, so that only the allocatable eviction threshold triggers
			initialConfig.EvictionHard = "nodefs.available<1"
			initialConfig.EvictionMinimumReclaim = ""
			framework.Logf("KubeReserved: %+v", initialConfig.KubeReserved)
		})
		runEvictionTest(f, pressureTimeout, expectedNodeCondition, logDiskMetrics, []podEvictSpec{
			{
				evictionPriority: 1,
				pod:              diskConsumingPod("container-disk-hog", 10000, nil, v1.ResourceRequirements{}),
			},
			{
				evictionPriority: 0,
				pod:              innocentPod(),
			},
		})
	})
})

// LocalStorageEviction tests that the node responds to node disk pressure by evicting only responsible pods
// Disk pressure is induced by running pods which consume disk space.
var _ = framework.KubeDescribe("LocalStorageEviction [Slow] [Serial] [Disruptive] [Flaky]", func() {
	f := framework.NewDefaultFramework("localstorage-eviction-test")
	pressureTimeout := 10 * time.Minute
	expectedNodeCondition := v1.NodeDiskPressure
	Context(fmt.Sprintf(testContextFmt, expectedNodeCondition), func() {
		tempSetCurrentKubeletConfig(f, func(initialConfig *kubeletconfig.KubeletConfiguration) {
			diskConsumed := uint64(100000000) // At least 100 Mb for pods to consume
			summary := eventuallyGetSummary()
			availableBytes := *(summary.Node.Fs.AvailableBytes)
			initialConfig.EvictionHard = fmt.Sprintf("nodefs.available<%d", availableBytes-diskConsumed)
			initialConfig.EvictionMinimumReclaim = ""
		})
		runEvictionTest(f, pressureTimeout, expectedNodeCondition, logDiskMetrics, []podEvictSpec{
			{
				evictionPriority: 1,
				pod:              diskConsumingPod("container-disk-hog", 10000, nil, v1.ResourceRequirements{}),
			},
			{
				evictionPriority: 0,
				pod:              innocentPod(),
			},
		})
	})
})

// LocalStorageEviction tests that the node responds to node disk pressure by evicting only responsible pods
// Disk pressure is induced by running pods which consume disk space, which exceed the soft eviction threshold.
// Note: This test's purpose is to test Soft Evictions.  Local storage was chosen since it is the least costly to run.
var _ = framework.KubeDescribe("LocalStorageSoftEviction [Slow] [Serial] [Disruptive] [Flaky]", func() {
	f := framework.NewDefaultFramework("localstorage-eviction-test")
	pressureTimeout := 10 * time.Minute
	expectedNodeCondition := v1.NodeDiskPressure
	Context(fmt.Sprintf(testContextFmt, expectedNodeCondition), func() {
		tempSetCurrentKubeletConfig(f, func(initialConfig *kubeletconfig.KubeletConfiguration) {
			diskConsumed := uint64(100000000) // At least 100 Mb for pods to consume
			summary := eventuallyGetSummary()
			availableBytes := *(summary.Node.Fs.AvailableBytes)
			initialConfig.EvictionSoft = fmt.Sprintf("nodefs.available<%d", availableBytes-diskConsumed)
			initialConfig.EvictionSoftGracePeriod = "nodefs.available=1m"
			// Defer to the pod default grace period
			initialConfig.EvictionMaxPodGracePeriod = 30
			initialConfig.EvictionMinimumReclaim = ""
			// Ensure that pods are not evicted because of the eviction-hard threshold
			initialConfig.EvictionHard = ""
		})
		runEvictionTest(f, pressureTimeout, expectedNodeCondition, logDiskMetrics, []podEvictSpec{
			{
				evictionPriority: 1,
				pod:              diskConsumingPod("container-disk-hog", 10000, nil, v1.ResourceRequirements{}),
			},
			{
				evictionPriority: 0,
				pod:              innocentPod(),
			},
		})
	})
})

// LocalStorageCapacityIsolationEviction tests that container and volume local storage limits are enforced through evictions
var _ = framework.KubeDescribe("LocalStorageCapacityIsolationEviction [Slow] [Serial] [Disruptive] [Flaky] [Feature:LocalStorageCapacityIsolation]", func() {
	f := framework.NewDefaultFramework("localstorage-eviction-test")
	evictionTestTimeout := 10 * time.Minute
	Context(fmt.Sprintf(testContextFmt, "evictions due to pod local storage violations"), func() {
		tempSetCurrentKubeletConfig(f, func(initialConfig *kubeletconfig.KubeletConfiguration) {
			if initialConfig.FeatureGates != "" {
				initialConfig.FeatureGates += ","
			}
			initialConfig.FeatureGates += "LocalStorageCapacityIsolation=true"
			initialConfig.EvictionHard = ""
		})
		sizeLimit := resource.MustParse("100Mi")
		used := int64(200) // Consume 200 Mb
		containerLimit := v1.ResourceList{v1.ResourceEphemeralStorage: sizeLimit}

		runEvictionTest(f, evictionTestTimeout, noPressure, logDiskMetrics, []podEvictSpec{
			{
				evictionPriority: 1, // This pod should be evicted because emptyDir (default storage type) usage violation
				pod: diskConsumingPod("emptydir-disk-sizelimit", used, &v1.VolumeSource{
					EmptyDir: &v1.EmptyDirVolumeSource{SizeLimit: &sizeLimit},
				}, v1.ResourceRequirements{}),
			},
			{
				evictionPriority: 1, // This pod should be evicted because of memory emptyDir usage violation
				pod: diskConsumingPod("emptydir-memory-sizelimit", used, &v1.VolumeSource{
					EmptyDir: &v1.EmptyDirVolumeSource{Medium: "Memory", SizeLimit: &sizeLimit},
				}, v1.ResourceRequirements{}),
			},
			{
				evictionPriority: 1, // This pod should cross the container limit by writing to its writable layer.
				pod:              diskConsumingPod("container-disk-limit", used, nil, v1.ResourceRequirements{Limits: containerLimit}),
			},
			{
				evictionPriority: 1, // This pod should hit the container limit by writing to an emptydir
				pod: diskConsumingPod("container-emptydir-disk-limit", used, &v1.VolumeSource{EmptyDir: &v1.EmptyDirVolumeSource{}},
					v1.ResourceRequirements{Limits: containerLimit}),
			},
			{
				evictionPriority: 0, // This pod should not be evicted because it uses less than its limit
				pod: diskConsumingPod("emptydir-disk-below-sizelimit", int64(50), &v1.VolumeSource{
					EmptyDir: &v1.EmptyDirVolumeSource{SizeLimit: &sizeLimit},
				}, v1.ResourceRequirements{}),
			},
		})
	})
})

// Struct used by runEvictionTest that specifies the pod, and when that pod should be evicted, relative to other pods
type podEvictSpec struct {
	// P0 should never be evicted, P1 shouldn't evict before P2, etc.
	// If two are ranked at P1, either is permitted to fail before the other.
	// The test ends when all pods other than p0 have been evicted
	evictionPriority int
	pod              *v1.Pod
}

// runEvictionTest sets up a testing environment given the provided pods, and checks a few things:
//		It ensures that the desired expectedNodeCondition is actually triggered.
//		It ensures that evictionPriority 0 pods are not evicted
//		It ensures that lower evictionPriority pods are always evicted before higher evictionPriority pods (2 evicted before 1, etc.)
//		It ensures that all pods with non-zero evictionPriority are eventually evicted.
// runEvictionTest then cleans up the testing environment by deleting provided pods, and ensures that expectedNodeCondition no longer exists
func runEvictionTest(f *framework.Framework, pressureTimeout time.Duration, expectedNodeCondition v1.NodeConditionType, logFunc func(), testSpecs []podEvictSpec) {
	// Place the remainder of the test within a context so that the kubelet config is set before and after the test.
	Context("", func() {
		BeforeEach(func() {
			// Nodes do not immediately report local storage capacity
			// Sleep so that pods requesting local storage do not fail to schedule
			time.Sleep(30 * time.Second)
			By("seting up pods to be used by tests")
			for _, spec := range testSpecs {
				By(fmt.Sprintf("creating pod with container: %s", spec.pod.Name))
				f.PodClient().CreateSync(spec.pod)
			}
		})

		It("should eventually evict all of the correct pods", func() {
			By(fmt.Sprintf("Waiting for node to have NodeCondition: %s", expectedNodeCondition))
			Eventually(func() error {
				logFunc()
				if expectedNodeCondition == noPressure || hasNodeCondition(f, expectedNodeCondition) {
					return nil
				}
				return fmt.Errorf("NodeCondition: %s not encountered", expectedNodeCondition)
			}, pressureTimeout, evictionPollInterval).Should(BeNil())

			By("Waiting for evictions to occur")
			Eventually(func() error {
				if expectedNodeCondition != noPressure {
					if hasNodeCondition(f, expectedNodeCondition) {
						framework.Logf("Node has %s", expectedNodeCondition)
					} else {
						framework.Logf("Node does NOT have %s", expectedNodeCondition)
					}
				}
				logKubeletMetrics(kubeletmetrics.EvictionStatsAgeKey)
				logFunc()
				return verifyEvictionOrdering(f, testSpecs)
			}, pressureTimeout, evictionPollInterval).Should(BeNil())

			// We observe pressure from the API server.  The eviction manager observes pressure from the kubelet internal stats.
			// This means the eviction manager will observe pressure before we will, creating a delay between when the eviction manager
			// evicts a pod, and when we observe the pressure by querying the API server.  Add a delay here to account for this delay
			By("making sure pressure from test has surfaced before continuing")
			time.Sleep(pressureDelay)

			By(fmt.Sprintf("Waiting for NodeCondition: %s to no longer exist on the node", expectedNodeCondition))
			Eventually(func() error {
				logFunc()
				logKubeletMetrics(kubeletmetrics.EvictionStatsAgeKey)
				if expectedNodeCondition != noPressure && hasNodeCondition(f, expectedNodeCondition) {
					return fmt.Errorf("Conditions havent returned to normal, node still has %s", expectedNodeCondition)
				}
				return nil
			}, pressureDissapearTimeout, evictionPollInterval).Should(BeNil())

			By("checking for stable, pressure-free condition without unexpected pod failures")
			Consistently(func() error {
				if expectedNodeCondition != noPressure && hasNodeCondition(f, expectedNodeCondition) {
					return fmt.Errorf("%s dissappeared and then reappeared", expectedNodeCondition)
				}
				logFunc()
				logKubeletMetrics(kubeletmetrics.EvictionStatsAgeKey)
				return verifyEvictionOrdering(f, testSpecs)
			}, postTestConditionMonitoringPeriod, evictionPollInterval).Should(BeNil())
		})

		AfterEach(func() {
			By("deleting pods")
			for _, spec := range testSpecs {
				By(fmt.Sprintf("deleting pod: %s", spec.pod.Name))
				f.PodClient().DeleteSync(spec.pod.Name, &metav1.DeleteOptions{}, 10*time.Minute)
			}
			if expectedNodeCondition == v1.NodeDiskPressure && framework.TestContext.PrepullImages {
				// The disk eviction test may cause the prepulled images to be evicted,
				// prepull those images again to ensure this test not affect following tests.
				PrePullAllImages()
			}
			By("making sure we can start a new pod after the test")
			podName := "test-admit-pod"
			f.PodClient().CreateSync(&v1.Pod{
				ObjectMeta: metav1.ObjectMeta{
					Name: podName,
				},
				Spec: v1.PodSpec{
					RestartPolicy: v1.RestartPolicyNever,
					Containers: []v1.Container{
						{
							Image: framework.GetPauseImageNameForHostArch(),
							Name:  podName,
						},
					},
				},
			})

			if CurrentGinkgoTestDescription().Failed {
				if framework.TestContext.DumpLogsOnFailure {
					logPodEvents(f)
					logNodeEvents(f)
				}
			}
		})
	})
}

// verifyEvictionOrdering returns an error if all non-zero priority pods have not been evicted, nil otherwise
// This function panics (via Expect) if eviction ordering is violated, or if a priority-zero pod fails.
func verifyEvictionOrdering(f *framework.Framework, testSpecs []podEvictSpec) error {
	// Gather current information
	updatedPodList, err := f.ClientSet.CoreV1().Pods(f.Namespace.Name).List(metav1.ListOptions{})
	if err != nil {
		return err
	}
	updatedPods := updatedPodList.Items
	for _, p := range updatedPods {
		framework.Logf("fetching pod %s; phase= %v", p.Name, p.Status.Phase)
	}

	By("checking eviction ordering and ensuring important pods dont fail")
	done := true
	for _, priorityPodSpec := range testSpecs {
		var priorityPod v1.Pod
		for _, p := range updatedPods {
			if p.Name == priorityPodSpec.pod.Name {
				priorityPod = p
			}
		}
		Expect(priorityPod).NotTo(BeNil())

		// Check eviction ordering.
		// Note: it is alright for a priority 1 and priority 2 pod (for example) to fail in the same round,
		// but never alright for a priority 1 pod to fail while the priority 2 pod is still running
		for _, lowPriorityPodSpec := range testSpecs {
			var lowPriorityPod v1.Pod
			for _, p := range updatedPods {
				if p.Name == lowPriorityPodSpec.pod.Name {
					lowPriorityPod = p
				}
			}
			Expect(lowPriorityPod).NotTo(BeNil())
			if priorityPodSpec.evictionPriority < lowPriorityPodSpec.evictionPriority && lowPriorityPod.Status.Phase == v1.PodRunning {
				Expect(priorityPod.Status.Phase).NotTo(Equal(v1.PodFailed),
					fmt.Sprintf("priority %d pod: %s failed before priority %d pod: %s",
						priorityPodSpec.evictionPriority, priorityPodSpec.pod.Name, lowPriorityPodSpec.evictionPriority, lowPriorityPodSpec.pod.Name))
			}
		}

		// EvictionPriority 0 pods should not fail
		if priorityPodSpec.evictionPriority == 0 {
			Expect(priorityPod.Status.Phase).NotTo(Equal(v1.PodFailed),
				fmt.Sprintf("priority 0 pod: %s failed", priorityPod.Name))
		}

		// If a pod that is not evictionPriority 0 has not been evicted, we are not done
		if priorityPodSpec.evictionPriority != 0 && priorityPod.Status.Phase != v1.PodFailed {
			done = false
		}
	}
	if done {
		return nil
	}
	return fmt.Errorf("pods that should be evicted are still running")
}

// Returns TRUE if the node has the node condition, FALSE otherwise
func hasNodeCondition(f *framework.Framework, expectedNodeCondition v1.NodeConditionType) bool {
	localNodeStatus := getLocalNode(f).Status
	_, actualNodeCondition := nodeutil.GetNodeCondition(&localNodeStatus, expectedNodeCondition)
	Expect(actualNodeCondition).NotTo(BeNil())
	return actualNodeCondition.Status == v1.ConditionTrue
}

func logInodeMetrics() {
	summary, err := getNodeSummary()
	if err != nil {
		framework.Logf("Error getting summary: %v", err)
		return
	}
	if summary.Node.Runtime != nil && summary.Node.Runtime.ImageFs != nil && summary.Node.Runtime.ImageFs.Inodes != nil && summary.Node.Runtime.ImageFs.InodesFree != nil {
		framework.Logf("imageFsInfo.Inodes: %d, imageFsInfo.InodesFree: %d", *summary.Node.Runtime.ImageFs.Inodes, *summary.Node.Runtime.ImageFs.InodesFree)
	}
	if summary.Node.Fs != nil && summary.Node.Fs.Inodes != nil && summary.Node.Fs.InodesFree != nil {
		framework.Logf("rootFsInfo.Inodes: %d, rootFsInfo.InodesFree: %d", *summary.Node.Fs.Inodes, *summary.Node.Fs.InodesFree)
	}
	for _, pod := range summary.Pods {
		framework.Logf("Pod: %s", pod.PodRef.Name)
		for _, container := range pod.Containers {
			if container.Rootfs != nil && container.Rootfs.InodesUsed != nil {
				framework.Logf("--- summary Container: %s inodeUsage: %d", container.Name, *container.Rootfs.InodesUsed)
			}
		}
		for _, volume := range pod.VolumeStats {
			if volume.FsStats.InodesUsed != nil {
				framework.Logf("--- summary Volume: %s inodeUsage: %d", volume.Name, *volume.FsStats.InodesUsed)
			}
		}
	}
}

func logDiskMetrics() {
	summary, err := getNodeSummary()
	if err != nil {
		framework.Logf("Error getting summary: %v", err)
		return
	}
	if summary.Node.Runtime != nil && summary.Node.Runtime.ImageFs != nil && summary.Node.Runtime.ImageFs.CapacityBytes != nil && summary.Node.Runtime.ImageFs.AvailableBytes != nil {
		framework.Logf("imageFsInfo.CapacityBytes: %d, imageFsInfo.AvailableBytes: %d", *summary.Node.Runtime.ImageFs.CapacityBytes, *summary.Node.Runtime.ImageFs.AvailableBytes)
	}
	if summary.Node.Fs != nil && summary.Node.Fs.CapacityBytes != nil && summary.Node.Fs.AvailableBytes != nil {
		framework.Logf("rootFsInfo.CapacityBytes: %d, rootFsInfo.AvailableBytes: %d", *summary.Node.Fs.CapacityBytes, *summary.Node.Fs.AvailableBytes)
	}
	for _, pod := range summary.Pods {
		framework.Logf("Pod: %s", pod.PodRef.Name)
		for _, container := range pod.Containers {
			if container.Rootfs != nil && container.Rootfs.UsedBytes != nil {
				framework.Logf("--- summary Container: %s UsedBytes: %d", container.Name, *container.Rootfs.UsedBytes)
			}
		}
		for _, volume := range pod.VolumeStats {
			if volume.FsStats.InodesUsed != nil {
				framework.Logf("--- summary Volume: %s UsedBytes: %d", volume.Name, *volume.FsStats.UsedBytes)
			}
		}
	}
}

func logMemoryMetrics() {
	summary, err := getNodeSummary()
	if err != nil {
		framework.Logf("Error getting summary: %v", err)
		return
	}
	if summary.Node.Memory != nil && summary.Node.Memory.WorkingSetBytes != nil && summary.Node.Memory.AvailableBytes != nil {
		framework.Logf("Node.Memory.WorkingSetBytes: %d, summary.Node.Memory.AvailableBytes: %d", *summary.Node.Memory.WorkingSetBytes, *summary.Node.Memory.AvailableBytes)
	}
	for _, pod := range summary.Pods {
		framework.Logf("Pod: %s", pod.PodRef.Name)
		for _, container := range pod.Containers {
			if container.Memory != nil && container.Memory.WorkingSetBytes != nil {
				framework.Logf("--- summary Container: %s WorkingSetBytes: %d", container.Name, *container.Memory.WorkingSetBytes)
			}
		}
	}
}

func eventuallyGetSummary() (s *stats.Summary) {
	Eventually(func() error {
		summary, err := getNodeSummary()
		if err != nil {
			return err
		}
		if summary == nil || summary.Node.Fs == nil || summary.Node.Fs.InodesFree == nil || summary.Node.Fs.AvailableBytes == nil {
			return fmt.Errorf("some part of data is nil")
		}
		s = summary
		return nil
	}, time.Minute, evictionPollInterval).Should(BeNil())
	return
}

// returns a pod that does not use any resources
func innocentPod() *v1.Pod {
	return &v1.Pod{
		ObjectMeta: metav1.ObjectMeta{Name: "innocent-pod"},
		Spec: v1.PodSpec{
			RestartPolicy: v1.RestartPolicyNever,
			Containers: []v1.Container{
				{
					Image: busyboxImage,
					Name:  "innocent-container",
					Command: []string{
						"sh",
						"-c",
						"while true; do sleep 5; done",
					},
				},
			},
		},
	}
}

const (
	volumeMountPath = "/test-mnt"
	volumeName      = "test-volume"
)

func inodeConsumingPod(name string, volumeSource *v1.VolumeSource) *v1.Pod {
	// Each iteration creates an empty file
	return podWithCommand(volumeSource, v1.ResourceRequirements{}, name, "i=0; while true; do touch %s${i}.txt; sleep 0.001; i=$((i+=1)); done;")
}

func diskConsumingPod(name string, diskConsumedMB int64, volumeSource *v1.VolumeSource, resources v1.ResourceRequirements) *v1.Pod {
	// Each iteration writes 1Mb to the file
	return podWithCommand(volumeSource, resources, name, fmt.Sprintf("i=0; while [ $i -lt %d ];", diskConsumedMB/100)+" do dd if=/dev/urandom of=%s${i} bs=100 count=1000000; i=$(($i+1)); done; while true; do sleep 5; done")
}

// podWithCommand returns a pod with the provided volumeSource and resourceRequirements.
// If a volumeSource is provided, then the volumeMountPath to the volume is inserted into the provided command.
func podWithCommand(volumeSource *v1.VolumeSource, resources v1.ResourceRequirements, name, command string) *v1.Pod {
	path := ""
	volumeMounts := []v1.VolumeMount{}
	volumes := []v1.Volume{}
	if volumeSource != nil {
		path = volumeMountPath
		volumeMounts = []v1.VolumeMount{{MountPath: volumeMountPath, Name: volumeName}}
		volumes = []v1.Volume{{Name: volumeName, VolumeSource: *volumeSource}}
	}
	return &v1.Pod{
		ObjectMeta: metav1.ObjectMeta{Name: fmt.Sprintf("%s-pod", name)},
		Spec: v1.PodSpec{
			RestartPolicy: v1.RestartPolicyNever,
			Containers: []v1.Container{
				{
					Image: busyboxImage,
					Name:  fmt.Sprintf("%s-container", name),
					Command: []string{
						"sh",
						"-c",
						fmt.Sprintf(command, filepath.Join(path, "file")),
					},
					Resources:    resources,
					VolumeMounts: volumeMounts,
				},
			},
			Volumes: volumes,
		},
	}
}