system_node_critical_test.go

Documentation: k8s.io/kubernetes/test/e2e_node

     1  /*
     2  Copyright 2019 The Kubernetes Authors.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package e2enode
    18  
    19  import (
    20  	"context"
    21  	"fmt"
    22  	"os"
    23  	"time"
    24  
    25  	v1 "k8s.io/api/core/v1"
    26  	"k8s.io/apimachinery/pkg/api/resource"
    27  	"k8s.io/apimachinery/pkg/util/uuid"
    28  	kubeapi "k8s.io/kubernetes/pkg/apis/core"
    29  	kubeletconfig "k8s.io/kubernetes/pkg/kubelet/apis/config"
    30  	evictionapi "k8s.io/kubernetes/pkg/kubelet/eviction/api"
    31  	"k8s.io/kubernetes/test/e2e/framework"
    32  	"k8s.io/kubernetes/test/e2e/nodefeature"
    33  	admissionapi "k8s.io/pod-security-admission/api"
    34  
    35  	"github.com/onsi/ginkgo/v2"
    36  	"github.com/onsi/gomega"
    37  )
    38  
    39  var _ = SIGDescribe("SystemNodeCriticalPod", framework.WithSlow(), framework.WithSerial(), framework.WithDisruptive(), nodefeature.SystemNodeCriticalPod, func() {
    40  	f := framework.NewDefaultFramework("system-node-critical-pod-test")
    41  	f.NamespacePodSecurityLevel = admissionapi.LevelPrivileged
    42  	// this test only manipulates pods in kube-system
    43  	f.SkipNamespaceCreation = true
    44  
    45  	ginkgo.AfterEach(func() {
    46  		if framework.TestContext.PrepullImages {
    47  			// The test may cause the prepulled images to be evicted,
    48  			// prepull those images again to ensure this test not affect following tests.
    49  			PrePullAllImages()
    50  		}
    51  	})
    52  
    53  	ginkgo.Context("when create a system-node-critical pod", func() {
    54  		tempSetCurrentKubeletConfig(f, func(ctx context.Context, initialConfig *kubeletconfig.KubeletConfiguration) {
    55  			diskConsumed := resource.MustParse("200Mi")
    56  			summary := eventuallyGetSummary(ctx)
    57  			availableBytes := *(summary.Node.Fs.AvailableBytes)
    58  			initialConfig.EvictionHard = map[string]string{string(evictionapi.SignalNodeFsAvailable): fmt.Sprintf("%d", availableBytes-uint64(diskConsumed.Value()))}
    59  			initialConfig.EvictionMinimumReclaim = map[string]string{}
    60  		})
    61  
    62  		// Place the remainder of the test within a context so that the kubelet config is set before and after the test.
    63  		ginkgo.Context("", func() {
    64  			var staticPodName, mirrorPodName, podPath string
    65  			ns := kubeapi.NamespaceSystem
    66  
    67  			ginkgo.BeforeEach(func(ctx context.Context) {
    68  				ginkgo.By("create a static system-node-critical pod")
    69  				staticPodName = "static-disk-hog-" + string(uuid.NewUUID())
    70  				mirrorPodName = staticPodName + "-" + framework.TestContext.NodeName
    71  				podPath = kubeletCfg.StaticPodPath
    72  				// define a static pod consuming disk gradually
    73  				// the upper limit is 1024 (iterations) * 10485760 bytes (10MB) = 10GB
    74  				err := createStaticSystemNodeCriticalPod(
    75  					podPath, staticPodName, ns, busyboxImage, v1.RestartPolicyNever, 1024,
    76  					"dd if=/dev/urandom of=file${i} bs=10485760 count=1 2>/dev/null; sleep .1;",
    77  				)
    78  				gomega.Expect(err).ShouldNot(gomega.HaveOccurred())
    79  
    80  				ginkgo.By("wait for the mirror pod to be running")
    81  				gomega.Eventually(ctx, func(ctx context.Context) error {
    82  					return checkMirrorPodRunning(ctx, f.ClientSet, mirrorPodName, ns)
    83  				}, time.Minute, time.Second*2).Should(gomega.Succeed())
    84  			})
    85  
    86  			ginkgo.It("should not be evicted upon DiskPressure", func(ctx context.Context) {
    87  				ginkgo.By("wait for the node to have DiskPressure condition")
    88  				gomega.Eventually(ctx, func(ctx context.Context) error {
    89  					if hasNodeCondition(ctx, f, v1.NodeDiskPressure) {
    90  						return nil
    91  					}
    92  					msg := fmt.Sprintf("NodeCondition: %s not encountered yet", v1.NodeDiskPressure)
    93  					framework.Logf(msg)
    94  					return fmt.Errorf(msg)
    95  				}, time.Minute*2, time.Second*4).Should(gomega.Succeed())
    96  
    97  				ginkgo.By("check if it's running all the time")
    98  				gomega.Consistently(ctx, func(ctx context.Context) error {
    99  					err := checkMirrorPodRunning(ctx, f.ClientSet, mirrorPodName, ns)
   100  					if err == nil {
   101  						framework.Logf("mirror pod %q is running", mirrorPodName)
   102  					} else {
   103  						framework.Logf(err.Error())
   104  					}
   105  					return err
   106  				}, time.Minute*8, time.Second*4).ShouldNot(gomega.HaveOccurred())
   107  			})
   108  			ginkgo.AfterEach(func(ctx context.Context) {
   109  				defer func() {
   110  					if framework.TestContext.PrepullImages {
   111  						// The test may cause the prepulled images to be evicted,
   112  						// prepull those images again to ensure this test not affect following tests.
   113  						PrePullAllImages()
   114  					}
   115  				}()
   116  				ginkgo.By("delete the static pod")
   117  				err := deleteStaticPod(podPath, staticPodName, ns)
   118  				gomega.Expect(err).ShouldNot(gomega.HaveOccurred())
   119  
   120  				ginkgo.By("wait for the mirror pod to disappear")
   121  				gomega.Eventually(ctx, func(ctx context.Context) error {
   122  					return checkMirrorPodDisappear(ctx, f.ClientSet, mirrorPodName, ns)
   123  				}, time.Minute, time.Second*2).Should(gomega.Succeed())
   124  
   125  				ginkgo.By("making sure that node no longer has DiskPressure")
   126  				gomega.Eventually(ctx, func(ctx context.Context) error {
   127  					if hasNodeCondition(ctx, f, v1.NodeDiskPressure) {
   128  						return fmt.Errorf("Conditions haven't returned to normal, node still has DiskPressure")
   129  					}
   130  					return nil
   131  				}, pressureDisappearTimeout, evictionPollInterval).Should(gomega.Succeed())
   132  			})
   133  		})
   134  	})
   135  })
   136  
   137  func createStaticSystemNodeCriticalPod(dir, name, namespace, image string, restart v1.RestartPolicy,
   138  	iterations int, command string) error {
   139  	template := `
   140  apiVersion: v1
   141  kind: Pod
   142  metadata:
   143    name: %s
   144    namespace: %s
   145  spec:
   146    priorityClassName: system-node-critical
   147    containers:
   148    - name: %s
   149      image: %s
   150      command: ["sh", "-c", "i=0; while [ $i -lt %d ]; do %s i=$(($i+1)); done; while true; do sleep 5; done"]
   151    restartPolicy: %s
   152  `
   153  	file := staticPodPath(dir, name, namespace)
   154  	podYaml := fmt.Sprintf(template, name, namespace, name, image, iterations, command, string(restart))
   155  
   156  	f, err := os.OpenFile(file, os.O_RDWR|os.O_TRUNC|os.O_CREATE, 0666)
   157  	if err != nil {
   158  		return err
   159  	}
   160  	defer f.Close()
   161  
   162  	_, err = f.WriteString(podYaml)
   163  	return err
   164  }
   165
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