Added an node e2e test for pod evictions due to disk pressure.

test/e2e/framework/test_context.go

@@ -71,6 +71,8 @@ type TestContextType struct {
 	NodeName string
 	// Whether to enable the QoS Cgroup Hierarchy or not
 	CgroupsPerQOS bool
+	// The hard eviction thresholds
+	EvictionHard string
 }
 
 type CloudConfig struct {
@@ -150,4 +152,5 @@ func RegisterClusterFlags() {
 func RegisterNodeFlags() {
 	flag.StringVar(&TestContext.NodeName, "node-name", "", "Name of the node to run tests on (node e2e suite only).")
 	flag.BoolVar(&TestContext.CgroupsPerQOS, "cgroups-per-qos", false, "Enable creation of QoS cgroup hierarchy, if true top level QoS and pod cgroups are created.")
+	flag.StringVar(&TestContext.EvictionHard, "eviction-hard", "", "The hard eviction thresholds. If set, pods get evicted when the specified resources drop below the thresholds.")
 }

test/e2e_node/disk_eviction_test.go

@@ -0,0 +1,190 @@
+/*
+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"
+	"os/exec"
+	"strings"
+	"time"
+
+	"k8s.io/kubernetes/pkg/api"
+	"k8s.io/kubernetes/pkg/kubelet/dockertools"
+	"k8s.io/kubernetes/pkg/util/uuid"
+	"k8s.io/kubernetes/test/e2e/framework"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+	client "k8s.io/kubernetes/pkg/client/unversioned"
+)
+
+const (
+	// podCheckInterval is the interval seconds between pod status checks.
+	podCheckInterval = time.Second * 2
+
+	dummyFile = "dummy."
+)
+
+// TODO: Leverage dynamic Kubelet settings when it's implemented to only modify the kubelet eviction option in this test.
+// To manually trigger the test on a node with disk space just over 15Gi :
+//   make test-e2e-node FOCUS="hard eviction test" TEST_ARGS="--eviction-hard=nodefs.available<15Gi"
+var _ = framework.KubeDescribe("Kubelet Eviction Manager [FLAKY] [Serial] [Disruptive]", func() {
+	f := framework.NewDefaultFramework("kubelet-eviction-manager")
+	var podClient *framework.PodClient
+	var c *client.Client
+	var n *api.Node
+
+	BeforeEach(func() {
+		podClient = f.PodClient()
+		c = f.Client
+		nodeList := framework.GetReadySchedulableNodesOrDie(c)
+		n = &nodeList.Items[0]
+	})
+
+	Describe("hard eviction test", func() {
+		Context("pod using the most disk space gets evicted when the node disk usage is above the eviction hard threshold", func() {
+			var busyPodName, idlePodName string
+			var containersToCleanUp map[string]bool
+
+			AfterEach(func() {
+				podClient.Delete(busyPodName, &api.DeleteOptions{})
+				podClient.Delete(idlePodName, &api.DeleteOptions{})
+				for container := range containersToCleanUp {
+					// TODO: to be container implementation agnostic
+					cmd := exec.Command("docker", "rm", "-f", strings.Trim(container, dockertools.DockerPrefix))
+					cmd.Run()
+				}
+			})
+
+			BeforeEach(func() {
+				if !evictionOptionIsSet() {
+					return
+				}
+
+				busyPodName = "to-evict" + string(uuid.NewUUID())
+				idlePodName = "idle" + string(uuid.NewUUID())
+				containersToCleanUp = make(map[string]bool)
+				podClient.Create(&api.Pod{
+					ObjectMeta: api.ObjectMeta{
+						Name: idlePodName,
+					},
+					Spec: api.PodSpec{
+						RestartPolicy: api.RestartPolicyNever,
+						Containers: []api.Container{
+							{
+								Image: ImageRegistry[pauseImage],
+								Name:  idlePodName,
+							},
+						},
+					},
+				})
+				podClient.Create(&api.Pod{
+					ObjectMeta: api.ObjectMeta{
+						Name: busyPodName,
+					},
+					Spec: api.PodSpec{
+						RestartPolicy: api.RestartPolicyNever,
+						Containers: []api.Container{
+							{
+								Image: ImageRegistry[busyBoxImage],
+								Name:  busyPodName,
+								// Filling the disk
+								Command: []string{"sh", "-c",
+									fmt.Sprintf("for NUM in `seq 1 1 1000`; do dd if=/dev/urandom of=%s.$NUM bs=4000000 count=10; sleep 3; done",
+										dummyFile)},
+							},
+						},
+					},
+				})
+			})
+
+			It("should evict the pod using the most disk space", func() {
+				if !evictionOptionIsSet() {
+					framework.Logf("test skipped because eviction option is not set")
+					return
+				}
+
+				evictionOccurred := false
+				Eventually(func() error {
+					if !evictionOccurred {
+						podData, err := podClient.Get(busyPodName)
+						if err != nil {
+							return err
+						}
+						recordContainerId(containersToCleanUp, podData.Status.ContainerStatuses)
+
+						err = verifyPodEviction(podData)
+						if err != nil {
+							return err
+						}
+						if !nodeHasDiskPressure(f.Client) {
+							return fmt.Errorf("expected disk pressure condition is not set")
+						}
+
+						podData, err = podClient.Get(idlePodName)
+						if err != nil {
+							return err
+						}
+						recordContainerId(containersToCleanUp, podData.Status.ContainerStatuses)
+
+						if podData.Status.Phase != api.PodRunning {
+							return fmt.Errorf("expected phase to be running. got %+v", podData.Status.Phase)
+						}
+
+						evictionOccurred = true
+					}
+
+					// After eviction happens the pod is evicted so eventually the node disk pressure should be gone.
+					if nodeHasDiskPressure(f.Client) {
+						return fmt.Errorf("expected disk pressure condition relief has not happened")
+					}
+					return nil
+				}, time.Minute*5, podCheckInterval).Should(BeNil())
+			})
+		})
+	})
+})
+
+func verifyPodEviction(podData *api.Pod) error {
+	if podData.Status.Phase != api.PodFailed {
+		return fmt.Errorf("expected phase to be failed. got %+v", podData.Status.Phase)
+	}
+	if podData.Status.Reason != "Evicted" {
+		return fmt.Errorf("expected failed reason to be evicted. got %+v", podData.Status.Reason)
+	}
+	return nil
+}
+
+func nodeHasDiskPressure(c *client.Client) bool {
+	nodeList := framework.GetReadySchedulableNodesOrDie(c)
+	for _, condition := range nodeList.Items[0].Status.Conditions {
+		if condition.Type == api.NodeDiskPressure {
+			return condition.Status == api.ConditionTrue
+		}
+	}
+	return false
+}
+
+func recordContainerId(containersToCleanUp map[string]bool, containerStatuses []api.ContainerStatus) {
+	for _, status := range containerStatuses {
+		containersToCleanUp[status.ContainerID] = true
+	}
+}
+
+func evictionOptionIsSet() bool {
+	return len(framework.TestContext.EvictionHard) > 0
+}

test/e2e_node/e2e_node_suite_test.go

@@ -118,7 +118,7 @@ var _ = SynchronizedBeforeSuite(func() []byte {
 
 	shared := &SharedContext{}
 	if *startServices {
-		e2es = newE2eService(framework.TestContext.NodeName, framework.TestContext.CgroupsPerQOS, shared)
+		e2es = newE2eService(framework.TestContext.NodeName, framework.TestContext.CgroupsPerQOS, framework.TestContext.EvictionHard, shared)
 		if err := e2es.start(); err != nil {
 			Fail(fmt.Sprintf("Unable to start node services.\n%v", err))
 		}

test/e2e_node/e2e_service.go

@@ -47,6 +47,7 @@ type e2eService struct {
 	nodeName      string
 	logFiles      map[string]logFileData
 	cgroupsPerQOS bool
+	evictionHard  string
 }
 
 type logFileData struct {
@@ -61,7 +62,7 @@ const (
 	defaultEtcdPath = "/tmp/etcd"
 )
 
-func newE2eService(nodeName string, cgroupsPerQOS bool, context *SharedContext) *e2eService {
+func newE2eService(nodeName string, cgroupsPerQOS bool, evictionHard string, context *SharedContext) *e2eService {
 	// Special log files that need to be collected for additional debugging.
 	var logFiles = map[string]logFileData{
 		"kern.log":   {[]string{"/var/log/kern.log"}, []string{"-k"}},
@@ -73,6 +74,7 @@ func newE2eService(nodeName string, cgroupsPerQOS bool, context *SharedContext)
 		nodeName:      nodeName,
 		logFiles:      logFiles,
 		cgroupsPerQOS: cgroupsPerQOS,
+		evictionHard:  evictionHard,
 	}
 }
 
@@ -256,6 +258,8 @@ func (es *e2eService) startKubeletServer() (*killCmd, error) {
 		"--file-check-frequency", "10s", // Check file frequently so tests won't wait too long
 		"--v", LOG_VERBOSITY_LEVEL, "--logtostderr",
 		"--pod-cidr=10.180.0.0/24", // Assign a fixed CIDR to the node because there is no node controller.
+		"--eviction-hard", es.evictionHard,
+		"--eviction-pressure-transition-period", "30s",
 	)
 	if es.cgroupsPerQOS {
 		cmdArgs = append(cmdArgs,