add e2e test for network partition

test/e2e/resize_nodes.go

@@ -33,13 +33,21 @@ import (
 
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
+	"k8s.io/kubernetes/pkg/client/cache"
 	awscloud "k8s.io/kubernetes/pkg/cloudprovider/providers/aws"
+	controllerframework "k8s.io/kubernetes/pkg/controller/framework"
+	"k8s.io/kubernetes/pkg/fields"
+	"k8s.io/kubernetes/pkg/runtime"
+	"k8s.io/kubernetes/pkg/watch"
 )
 
 const (
 	serveHostnameImage        = "gcr.io/google_containers/serve_hostname:1.1"
 	resizeNodeReadyTimeout    = 2 * time.Minute
 	resizeNodeNotReadyTimeout = 2 * time.Minute
+	nodeReadinessTimeout      = 3 * time.Minute
+	podNotReadyTimeout        = 1 * time.Minute
+	podReadyTimeout           = 2 * time.Minute
 	testPort                  = 9376
 )
 
@@ -287,14 +295,69 @@ func verifyPods(c *client.Client, ns, name string, wantName bool, replicas int)
 	return nil
 }
 
-// Blocks outgoing network traffic on 'node'. Then verifies that 'podNameToDisappear',
-// that belongs to replication controller 'rcName', really disappeared.
-// Finally, it checks that the replication controller recreates the
-// pods on another node and that now the number of replicas is equal 'replicas'.
-// At the end (even in case of errors), the network traffic is brought back to normal.
-// This function executes commands on a node so it will work only for some
-// environments.
-func performTemporaryNetworkFailure(c *client.Client, ns, rcName string, replicas int, podNameToDisappear string, node *api.Node) {
+func blockNetwork(from string, to string) {
+	Logf("block network traffic from %s to %s", from, to)
+	iptablesRule := fmt.Sprintf("OUTPUT --destination %s --jump REJECT", to)
+	dropCmd := fmt.Sprintf("sudo iptables --insert %s", iptablesRule)
+	if result, err := SSH(dropCmd, from, testContext.Provider); result.Code != 0 || err != nil {
+		LogSSHResult(result)
+		Failf("Unexpected error: %v", err)
+	}
+}
+
+func unblockNetwork(from string, to string) {
+	Logf("Unblock network traffic from %s to %s", from, to)
+	iptablesRule := fmt.Sprintf("OUTPUT --destination %s --jump REJECT", to)
+	undropCmd := fmt.Sprintf("sudo iptables --delete %s", iptablesRule)
+	// Undrop command may fail if the rule has never been created.
+	// In such case we just lose 30 seconds, but the cluster is healthy.
+	// But if the rule had been created and removing it failed, the node is broken and
+	// not coming back. Subsequent tests will run or fewer nodes (some of the tests
+	// may fail). Manual intervention is required in such case (recreating the
+	// cluster solves the problem too).
+	err := wait.Poll(time.Millisecond*100, time.Second*30, func() (bool, error) {
+		result, err := SSH(undropCmd, from, testContext.Provider)
+		if result.Code == 0 && err == nil {
+			return true, nil
+		}
+		LogSSHResult(result)
+		if err != nil {
+			Logf("Unexpected error: %v", err)
+		}
+		return false, nil
+	})
+	if err != nil {
+		Failf("Failed to remove the iptable REJECT rule. Manual intervention is "+
+			"required on host %s: remove rule %s, if exists", from, iptablesRule)
+	}
+}
+
+func getMaster(c *client.Client) string {
+	master := ""
+	switch testContext.Provider {
+	case "gce":
+		eps, err := c.Endpoints(api.NamespaceDefault).Get("kubernetes")
+		if err != nil {
+			Failf("Fail to get kubernetes endpoinds: %v", err)
+		}
+		if len(eps.Subsets) != 1 || len(eps.Subsets[0].Addresses) != 1 {
+			Failf("There are more than 1 endpoints for kubernetes service: %+v", eps)
+		}
+		master = eps.Subsets[0].Addresses[0].IP
+	case "gke":
+		master = strings.TrimPrefix(testContext.Host, "https://")
+	case "aws":
+		// TODO(justinsb): Avoid hardcoding this.
+		master = "172.20.0.9"
+	default:
+		Failf("This test is not supported for provider %s and should be disabled", testContext.Provider)
+	}
+	return master
+}
+
+// Return node external IP concatenated with port 22 for ssh
+// e.g. 1.2.3.4:22
+func getNodeExternalIP(node *api.Node) string {
 	Logf("Getting external IP address for %s", node.Name)
 	host := ""
 	for _, a := range node.Status.Addresses {
@@ -306,71 +369,34 @@ func performTemporaryNetworkFailure(c *client.Client, ns, rcName string, replica
 	if host == "" {
 		Failf("Couldn't get the external IP of host %s with addresses %v", node.Name, node.Status.Addresses)
 	}
+	return host
+}
 
+// Blocks outgoing network traffic on 'node'. Then verifies that 'podNameToDisappear',
+// that belongs to replication controller 'rcName', really disappeared.
+// Finally, it checks that the replication controller recreates the
+// pods on another node and that now the number of replicas is equal 'replicas'.
+// At the end (even in case of errors), the network traffic is brought back to normal.
+// This function executes commands on a node so it will work only for some
+// environments.
+func performTemporaryNetworkFailure(c *client.Client, ns, rcName string, replicas int, podNameToDisappear string, node *api.Node) {
+	host := getNodeExternalIP(node)
+	master := getMaster(c)
 	By(fmt.Sprintf("block network traffic from node %s to the master", node.Name))
-	master := ""
-	switch testContext.Provider {
-	case "gce":
-		// TODO(#10085): The use of MasterName will cause iptables to do a DNS
-		// lookup to resolve the name to an IP address, which will slow down the
-		// test and cause it to fail if DNS is absent or broken. Use the
-		// internal IP address instead (i.e. NOT the one in testContext.Host).
-		master = testContext.CloudConfig.MasterName
-	case "gke":
-		master = strings.TrimPrefix(testContext.Host, "https://")
-	case "aws":
-		// TODO(justinsb): Avoid hardcoding this.
-		master = "172.20.0.9"
-	default:
-		Failf("This test is not supported for provider %s and should be disabled", testContext.Provider)
-	}
-	iptablesRule := fmt.Sprintf("OUTPUT --destination %s --jump REJECT", master)
 	defer func() {
 		// This code will execute even if setting the iptables rule failed.
 		// It is on purpose because we may have an error even if the new rule
 		// had been inserted. (yes, we could look at the error code and ssh error
 		// separately, but I prefer to stay on the safe side).
-
 		By(fmt.Sprintf("Unblock network traffic from node %s to the master", node.Name))
-		undropCmd := fmt.Sprintf("sudo iptables --delete %s", iptablesRule)
-		// Undrop command may fail if the rule has never been created.
-		// In such case we just lose 30 seconds, but the cluster is healthy.
-		// But if the rule had been created and removing it failed, the node is broken and
-		// not coming back. Subsequent tests will run or fewer nodes (some of the tests
-		// may fail). Manual intervention is required in such case (recreating the
-		// cluster solves the problem too).
-		err := wait.Poll(time.Millisecond*100, time.Second*30, func() (bool, error) {
-			result, err := SSH(undropCmd, host, testContext.Provider)
-			if result.Code == 0 && err == nil {
-				return true, nil
-			}
-			LogSSHResult(result)
-			if err != nil {
-				Logf("Unexpected error: %v", err)
-			}
-			return false, nil
-		})
-		if err != nil {
-			Failf("Failed to remove the iptable REJECT rule. Manual intervention is "+
-				"required on node %s: remove rule %s, if exists", node.Name, iptablesRule)
-		}
+		unblockNetwork(host, master)
 	}()
 
 	Logf("Waiting %v to ensure node %s is ready before beginning test...", resizeNodeReadyTimeout, node.Name)
 	if !waitForNodeToBe(c, node.Name, api.NodeReady, true, resizeNodeReadyTimeout) {
 		Failf("Node %s did not become ready within %v", node.Name, resizeNodeReadyTimeout)
 	}
-
-	// The command will block all outgoing network traffic from the node to the master
-	// When multi-master is implemented, this test will have to be improved to block
-	// network traffic to all masters.
-	// We could also block network traffic from the master(s) to this node,
-	// but blocking it one way is sufficient for this test.
-	dropCmd := fmt.Sprintf("sudo iptables --insert %s", iptablesRule)
-	if result, err := SSH(dropCmd, host, testContext.Provider); result.Code != 0 || err != nil {
-		LogSSHResult(result)
-		Failf("Unexpected error: %v", err)
-	}
+	blockNetwork(host, master)
 
 	Logf("Waiting %v for node %s to be not ready after simulated network failure", resizeNodeNotReadyTimeout, node.Name)
 	if !waitForNodeToBe(c, node.Name, api.NodeReady, false, resizeNodeNotReadyTimeout) {
@@ -388,12 +414,32 @@ func performTemporaryNetworkFailure(c *client.Client, ns, rcName string, replica
 	// network traffic is unblocked in a deferred function
 }
 
+func expectNodeReadiness(isReady bool, newNode chan *api.Node) {
+	timeout := false
+	expected := false
+	timer := time.After(nodeReadinessTimeout)
+	for !expected && !timeout {
+		select {
+		case n := <-newNode:
+			if isNodeConditionSetAsExpected(n, api.NodeReady, isReady) {
+				expected = true
+			} else {
+				Logf("Observed node ready status is NOT %v as expected", isReady)
+			}
+		case <-timer:
+			timeout = true
+		}
+	}
+	if !expected {
+		Failf("Failed to observe node ready status change to %v", isReady)
+	}
+}
+
 var _ = Describe("Nodes [Disruptive]", func() {
 	framework := NewFramework("resize-nodes")
 	var systemPodsNo int
 	var c *client.Client
 	var ns string
-
 	BeforeEach(func() {
 		c = framework.Client
 		ns = framework.Namespace.Name
@@ -560,6 +606,101 @@ var _ = Describe("Nodes [Disruptive]", func() {
 					}
 				}
 			})
+
+			// What happens in this test:
+			// 	Network traffic from a node to master is cut off to simulate network partition
+			// Expect to observe:
+			// 1. Node is marked NotReady after timeout by nodecontroller (40seconds)
+			// 2. All pods on node are marked NotReady shortly after #1
+			// 3. Node and pods return to Ready after connectivivty recovers
+			It("All pods on the unreachable node should be marked as NotReady upon the node turn NotReady "+
+				"AND all pods should be mark back to Ready when the node get back to Ready before pod eviction timeout", func() {
+				By("choose a node - we will block all network traffic on this node")
+				var podOpts api.ListOptions
+				nodeOpts := api.ListOptions{}
+				nodes, err := c.Nodes().List(nodeOpts)
+				Expect(err).NotTo(HaveOccurred())
+				filterNodes(nodes, func(node api.Node) bool {
+					if !isNodeConditionSetAsExpected(&node, api.NodeReady, true) {
+						return false
+					}
+					podOpts = api.ListOptions{FieldSelector: fields.OneTermEqualSelector(client.PodHost, node.Name)}
+					pods, err := c.Pods(api.NamespaceAll).List(podOpts)
+					if err != nil || len(pods.Items) <= 0 {
+						return false
+					}
+					return true
+				})
+				if len(nodes.Items) <= 0 {
+					Failf("No eligible node were found: %d", len(nodes.Items))
+				}
+				node := nodes.Items[0]
+				podOpts = api.ListOptions{FieldSelector: fields.OneTermEqualSelector(client.PodHost, node.Name)}
+				if err = waitForMatchPodsCondition(c, podOpts, "Running and Ready", podReadyTimeout, podRunningReady); err != nil {
+					Failf("Pods on node %s are not ready and running within %v: %v", node.Name, podReadyTimeout, err)
+				}
+
+				By("Set up watch on node status")
+				nodeSelector := fields.OneTermEqualSelector("metadata.name", node.Name)
+				stopCh := make(chan struct{})
+				newNode := make(chan *api.Node)
+				var controller *controllerframework.Controller
+				_, controller = controllerframework.NewInformer(
+					&cache.ListWatch{
+						ListFunc: func(options api.ListOptions) (runtime.Object, error) {
+							options.FieldSelector = nodeSelector
+							return framework.Client.Nodes().List(options)
+						},
+						WatchFunc: func(options api.ListOptions) (watch.Interface, error) {
+							options.FieldSelector = nodeSelector
+							return framework.Client.Nodes().Watch(options)
+						},
+					},
+					&api.Node{},
+					0,
+					controllerframework.ResourceEventHandlerFuncs{
+						UpdateFunc: func(oldObj, newObj interface{}) {
+							n, ok := newObj.(*api.Node)
+							Expect(ok).To(Equal(true))
+							newNode <- n
+
+						},
+					},
+				)
+
+				defer func() {
+					// Will not explicitly close newNode channel here due to
+					// race condition where stopCh and newNode are closed but informer onUpdate still executes.
+					close(stopCh)
+				}()
+				go controller.Run(stopCh)
+
+				By(fmt.Sprintf("Block traffic from node %s to the master", node.Name))
+				host := getNodeExternalIP(&node)
+				master := getMaster(c)
+				defer func() {
+					By(fmt.Sprintf("Unblock traffic from node %s to the master", node.Name))
+					unblockNetwork(host, master)
+
+					if CurrentGinkgoTestDescription().Failed {
+						return
+					}
+
+					By("Expect to observe node and pod status change from NotReady to Ready after network connectivity recovers")
+					expectNodeReadiness(true, newNode)
+					if err = waitForMatchPodsCondition(c, podOpts, "Running and Ready", podReadyTimeout, podRunningReady); err != nil {
+						Failf("Pods on node %s did not become ready and running within %v: %v", node.Name, podReadyTimeout, err)
+					}
+				}()
+
+				blockNetwork(host, master)
+
+				By("Expect to observe node and pod status change from Ready to NotReady after network partition")
+				expectNodeReadiness(false, newNode)
+				if err = waitForMatchPodsCondition(c, podOpts, "NotReady", podNotReadyTimeout, podNotReady); err != nil {
+					Failf("Pods on node %s did not become NotReady within %v: %v", node.Name, podNotReadyTimeout, err)
+				}
+			})
 		})
 	})
 })

test/e2e/util.go

@@ -46,6 +46,7 @@ import (
 	"k8s.io/kubernetes/pkg/cloudprovider"
 	"k8s.io/kubernetes/pkg/fields"
 	"k8s.io/kubernetes/pkg/kubectl"
+	"k8s.io/kubernetes/pkg/kubelet/util/format"
 	"k8s.io/kubernetes/pkg/labels"
 	"k8s.io/kubernetes/pkg/runtime"
 	"k8s.io/kubernetes/pkg/util"
@@ -354,6 +355,16 @@ func podRunningReady(p *api.Pod) (bool, error) {
 	return true, nil
 }
 
+// podNotReady checks whether pod p's has a ready condition of status false.
+func podNotReady(p *api.Pod) (bool, error) {
+	// Check the ready condition is false.
+	if podReady(p) {
+		return false, fmt.Errorf("pod '%s' on '%s' didn't have condition {%v %v}; conditions: %v",
+			p.ObjectMeta.Name, p.Spec.NodeName, api.PodReady, api.ConditionFalse, p.Status.Conditions)
+	}
+	return true, nil
+}
+
 // check if a Pod is controlled by a Replication Controller in the List
 func hasReplicationControllersForPod(rcs *api.ReplicationControllerList, pod api.Pod) bool {
 	for _, rc := range rcs.Items {
@@ -545,6 +556,33 @@ func waitForPodCondition(c *client.Client, ns, podName, desc string, timeout tim
 	return fmt.Errorf("gave up waiting for pod '%s' to be '%s' after %v", podName, desc, timeout)
 }
 
+// waitForMatchPodsCondition finds match pods based on the input ListOptions.
+// waits and checks if all match pods are in the given podCondition
+func waitForMatchPodsCondition(c *client.Client, opts api.ListOptions, desc string, timeout time.Duration, condition podCondition) error {
+	Logf("Waiting up to %v for matching pods' status to be %s", timeout, desc)
+	for start := time.Now(); time.Since(start) < timeout; time.Sleep(poll) {
+		pods, err := c.Pods(api.NamespaceAll).List(opts)
+		if err != nil {
+			return err
+		}
+		conditionNotMatch := []string{}
+		for _, pod := range pods.Items {
+			done, err := condition(&pod)
+			if done && err != nil {
+				return fmt.Errorf("Unexpected error: %v", err)
+			}
+			if !done {
+				conditionNotMatch = append(conditionNotMatch, format.Pod(&pod))
+			}
+		}
+		if len(conditionNotMatch) <= 0 {
+			return err
+		}
+		Logf("%d pods are not %s", len(conditionNotMatch), desc)
+	}
+	return fmt.Errorf("gave up waiting for matching pods to be '%s' after %v", desc, timeout)
+}
+
 // waitForDefaultServiceAccountInNamespace waits for the default service account to be provisioned
 // the default service account is what is associated with pods when they do not specify a service account
 // as a result, pods are not able to be provisioned in a namespace until the service account is provisioned