k3s/test/e2e/resize_nodes.go

/*
Copyright 2015 The Kubernetes Authors All rights reserved.

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

import (
	"fmt"
	"os/exec"
	"strconv"
	"strings"
	"time"

	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
	"github.com/GoogleCloudPlatform/kubernetes/pkg/client"
	"github.com/GoogleCloudPlatform/kubernetes/pkg/fields"
	"github.com/GoogleCloudPlatform/kubernetes/pkg/labels"
	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
	"github.com/GoogleCloudPlatform/kubernetes/pkg/util/wait"

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

var serveHostnameImage string = "gcr.io/google_containers/serve_hostname:1.1"

func resizeNodeInstanceGroup(size int) error {
	// TODO: make this hit the compute API directly instread of shelling out to gcloud.
	output, err := exec.Command("gcloud", "preview", "managed-instance-groups", "--project="+testContext.CloudConfig.ProjectID, "--zone="+testContext.CloudConfig.Zone,
		"resize", testContext.CloudConfig.NodeInstanceGroup, fmt.Sprintf("--new-size=%v", size)).CombinedOutput()
	if err != nil {
		Logf("Failed to resize node instance group: %v", string(output))
	}
	return err
}

func nodeInstanceGroupSize() (int, error) {
	// TODO: make this hit the compute API directly instread of shelling out to gcloud.
	output, err := exec.Command("gcloud", "preview", "managed-instance-groups", "--project="+testContext.CloudConfig.ProjectID,
		"--zone="+testContext.CloudConfig.Zone, "describe", testContext.CloudConfig.NodeInstanceGroup).CombinedOutput()
	if err != nil {
		return -1, err
	}
	pattern := "currentSize: "
	i := strings.Index(string(output), pattern)
	if i == -1 {
		return -1, fmt.Errorf("could not find '%s' in the output '%s'", pattern, output)
	}
	truncated := output[i+len(pattern):]
	j := strings.Index(string(truncated), "\n")
	if j == -1 {
		return -1, fmt.Errorf("could not find new line in the truncated output '%s'", truncated)
	}

	currentSize, err := strconv.Atoi(string(truncated[:j]))
	if err != nil {
		return -1, err
	}
	return currentSize, nil
}

func waitForNodeInstanceGroupSize(size int) error {
	for start := time.Now(); time.Since(start) < 4*time.Minute; time.Sleep(5 * time.Second) {
		currentSize, err := nodeInstanceGroupSize()
		if err != nil {
			Logf("Failed to get node instance group size: %v", err)
			continue
		}
		if currentSize != size {
			Logf("Waiting for node instance group size %d, current size %d", size, currentSize)
			continue
		}
		Logf("Node instance group has reached the desired size %d", size)
		return nil
	}
	return fmt.Errorf("timeout waiting for node instance group size to be %d", size)
}

func waitForClusterSize(c *client.Client, size int) error {
	for start := time.Now(); time.Since(start) < 4*time.Minute; time.Sleep(20 * time.Second) {
		nodes, err := c.Nodes().List(labels.Everything(), fields.Everything())
		if err != nil {
			Logf("Failed to list nodes: %v", err)
			continue
		}
		if len(nodes.Items) == size {
			Logf("Cluster has reached the desired size %d", size)
			return nil
		}
		Logf("Waiting for cluster size %d, current size %d", size, len(nodes.Items))
	}
	return fmt.Errorf("timeout waiting for cluster size to be %d", size)
}

func newServiceWithNameSelector(name string) *api.Service {
	return &api.Service{
		ObjectMeta: api.ObjectMeta{
			Name: "test-service",
		},
		Spec: api.ServiceSpec{
			Selector: map[string]string{
				"name": name,
			},
			Ports: []api.ServicePort{{
				Port:       9376,
				TargetPort: util.NewIntOrStringFromInt(9376),
			}},
		},
	}
}

func createServiceWithNameSelector(c *client.Client, ns, name string) error {
	_, err := c.Services(ns).Create(newServiceWithNameSelector(name))
	return err
}

func newPodOnNode(podName, nodeName string, image string) *api.Pod {
	return &api.Pod{
		ObjectMeta: api.ObjectMeta{
			Name: podName,
			Labels: map[string]string{
				"name": podName,
			},
		},
		Spec: api.PodSpec{
			Containers: []api.Container{
				{
					Name:  podName,
					Image: image,
					Ports: []api.ContainerPort{{ContainerPort: 9376}},
				},
			},
			NodeName:      nodeName,
			RestartPolicy: api.RestartPolicyNever,
		},
	}
}

func createServeHostnamePodOnNode(c *client.Client, namespace, podName, nodeName string) error {
	pod, err := c.Pods(namespace).Create(newPodOnNode(podName, nodeName, serveHostnameImage))
	if err == nil {
		Logf("Created pod %s on node %s", pod.ObjectMeta.Name, nodeName)
	} else {
		Logf("Failed to create pod %s on node %s: %s", podName, nodeName, err)
	}
	return err
}

func newReplicationControllerWithNameSelector(name string, replicas int, image string) *api.ReplicationController {
	return &api.ReplicationController{
		ObjectMeta: api.ObjectMeta{
			Name: name,
		},
		Spec: api.ReplicationControllerSpec{
			Replicas: replicas,
			Selector: map[string]string{
				"name": name,
			},
			Template: &api.PodTemplateSpec{
				ObjectMeta: api.ObjectMeta{
					Labels: map[string]string{"name": name},
				},
				Spec: api.PodSpec{
					Containers: []api.Container{
						{
							Name:  name,
							Image: image,
							Ports: []api.ContainerPort{{ContainerPort: 9376}},
						},
					},
				},
			},
		},
	}
}

func createServeHostnameReplicationController(c *client.Client, ns, name string, replicas int) (*api.ReplicationController, error) {
	By(fmt.Sprintf("creating replication controller %s", name))
	return c.ReplicationControllers(ns).Create(newReplicationControllerWithNameSelector(name, replicas, serveHostnameImage))
}

func resizeReplicationController(c *client.Client, ns, name string, replicas int) error {
	rc, err := c.ReplicationControllers(ns).Get(name)
	if err != nil {
		return err
	}
	rc.Spec.Replicas = replicas
	_, err = c.ReplicationControllers(rc.Namespace).Update(rc)
	return err
}

func waitForPodsCreated(c *client.Client, ns, name string, replicas int) (*api.PodList, error) {
	// List the pods, making sure we observe all the replicas.
	label := labels.SelectorFromSet(labels.Set(map[string]string{"name": name}))
	for start := time.Now(); time.Since(start) < time.Minute; time.Sleep(5 * time.Second) {
		pods, err := c.Pods(ns).List(label, fields.Everything())
		if err != nil {
			return nil, err
		}

		Logf("Pod name %s: Found %d pods out of %d", name, len(pods.Items), replicas)
		if len(pods.Items) == replicas {
			return pods, nil
		}
	}
	return nil, fmt.Errorf("Pod name %s: Gave up waiting for %d pods to come up", name, replicas)
}

func waitForPodsRunning(c *client.Client, pods *api.PodList) []error {
	// Wait for the pods to enter the running state. Waiting loops until the pods
	// are running so non-running pods cause a timeout for this test.
	By("ensuring each pod is running")
	e := []error{}
	for _, pod := range pods.Items {
		// TODO: make waiting parallel.
		err := waitForPodRunningInNamespace(c, pod.Name, pod.Namespace)
		if err != nil {
			e = append(e, err)
		}
	}
	return e
}

func verifyPodsResponding(c *client.Client, ns, name string, pods *api.PodList) error {
	By("trying to dial each unique pod")
	retryTimeout := 2 * time.Minute
	retryInterval := 5 * time.Second
	label := labels.SelectorFromSet(labels.Set(map[string]string{"name": name}))
	return wait.Poll(retryInterval, retryTimeout, podResponseChecker{c, ns, label, name, pods}.checkAllResponses)
}

func waitForPodsCreatedRunningResponding(c *client.Client, ns, name string, replicas int) error {
	pods, err := waitForPodsCreated(c, ns, name, replicas)
	if err != nil {
		return err
	}
	e := waitForPodsRunning(c, pods)
	if len(e) > 0 {
		return fmt.Errorf("Failed to wait for pods running: %v", e)
	}
	err = verifyPodsResponding(c, ns, name, pods)
	if err != nil {
		return err
	}
	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) {
	Logf("Getting external IP address for %s", node.Name)
	host := ""
	for _, a := range node.Status.Addresses {
		if a.Type == api.NodeExternalIP {
			host = a.Address + ":22"
			break
		}
	}
	if host == "" {
		Failf("Couldn't get the external IP of host %s with addresses %v", node.Name, node.Status.Addresses)
	}
	By(fmt.Sprintf("block network traffic from node %s to the master", node.Name))

	// TODO: 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 IP address instead.
	iptablesRule := fmt.Sprintf("OUTPUT --destination %s --jump DROP", testContext.CloudConfig.MasterName)
	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) {
			_, _, code, err := SSH(undropCmd, host, testContext.Provider)
			if code == 0 && err == nil {
				return true, nil
			} else {
				Logf("Expected 0 exit code and nil error when running '%s' on %s, got %d and %v",
					undropCmd, node.Name, code, err)
				return false, nil
			}
		})
		if err != nil {
			Failf("Failed to remove the iptable DROP rule. Manual intervention is "+
				"required on node %s: remove rule %s, if exists", node.Name, iptablesRule)
		}
	}()

	// 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)s to this node,
	// but blocking it one way is sufficient for this test.
	dropCmd := fmt.Sprintf("sudo iptables --insert %s", iptablesRule)
	if _, _, code, err := SSH(dropCmd, host, testContext.Provider); code != 0 || err != nil {
		Failf("Expected 0 exit code and nil error when running %s on %s, got %d and %v",
			dropCmd, node.Name, code, err)
	}

	Logf("Waiting for node %s to be not ready", node.Name)
	waitForNodeToBe(c, node.Name, false, 2*time.Minute)

	Logf("Waiting for pod %s to be removed", podNameToDisappear)
	waitForRCPodToDisappear(c, ns, rcName, podNameToDisappear)

	By("verifying whether the pod from the unreachable node is recreated")
	err := waitForPodsCreatedRunningResponding(c, ns, rcName, replicas)
	Expect(err).NotTo(HaveOccurred())

	// network traffic is unblocked in a defered function
}

var _ = Describe("Nodes", func() {
	supportedProviders := []string{"gce", "gke"}
	var testName string
	var c *client.Client
	var ns string

	BeforeEach(func() {
		var err error
		c, err = loadClient()
		expectNoError(err)
		testingNs, err := createTestingNS("resize-nodes", c)
		ns = testingNs.Name
		Expect(err).NotTo(HaveOccurred())
	})

	AfterEach(func() {
		By(fmt.Sprintf("destroying namespace for this suite %s", ns))
		if err := c.Namespaces().Delete(ns); err != nil {
			Failf("Couldn't delete namespace '%s', %v", ns, err)
		}
	})

	Describe("Resize", func() {
		BeforeEach(func() {
			if !providerIs(supportedProviders...) {
				Failf("Nodes.Resize test is only supported for providers %v (not %s). You can avoid this failure by using ginkgo.skip=Nodes.Resize in your environment.",
					supportedProviders, testContext.Provider)
			}
		})

		AfterEach(func() {
			if !providerIs(supportedProviders...) {
				return
			}
			By("restoring the original node instance group size")
			if err := resizeNodeInstanceGroup(testContext.CloudConfig.NumNodes); err != nil {
				Failf("Couldn't restore the original node instance group size: %v", err)
			}
			if err := waitForNodeInstanceGroupSize(testContext.CloudConfig.NumNodes); err != nil {
				Failf("Couldn't restore the original node instance group size: %v", err)
			}
			if err := waitForClusterSize(c, testContext.CloudConfig.NumNodes); err != nil {
				Failf("Couldn't restore the original cluster size: %v", err)
			}
		})

		testName = "should be able to delete nodes."
		It(testName, func() {
			Logf("starting test %s", testName)

			if testContext.CloudConfig.NumNodes < 2 {
				Failf("Failing test %s as it requires at least 2 nodes (not %d)", testName, testContext.CloudConfig.NumNodes)
				return
			}

			// Create a replication controller for a service that serves its hostname.
			// The source for the Docker containter kubernetes/serve_hostname is in contrib/for-demos/serve_hostname
			name := "my-hostname-delete-node"
			replicas := testContext.CloudConfig.NumNodes
			createServeHostnameReplicationController(c, ns, name, replicas)
			err := waitForPodsCreatedRunningResponding(c, ns, name, replicas)
			Expect(err).NotTo(HaveOccurred())

			By(fmt.Sprintf("decreasing cluster size to %d", replicas-1))
			err = resizeNodeInstanceGroup(replicas - 1)
			Expect(err).NotTo(HaveOccurred())
			err = waitForNodeInstanceGroupSize(replicas - 1)
			Expect(err).NotTo(HaveOccurred())
			err = waitForClusterSize(c, replicas-1)
			Expect(err).NotTo(HaveOccurred())

			By("verifying whether the pods from the removed node are recreated")
			err = waitForPodsCreatedRunningResponding(c, ns, name, replicas)
			Expect(err).NotTo(HaveOccurred())
		})

		testName = "should be able to add nodes."
		It(testName, func() {
			// TODO: Bug here - testName is not correct
			Logf("starting test %s", testName)

			if testContext.CloudConfig.NumNodes < 2 {
				Failf("Failing test %s as it requires at least 2 nodes (not %d)", testName, testContext.CloudConfig.NumNodes)
				return
			}

			// Create a replication controller for a service that serves its hostname.
			// The source for the Docker containter kubernetes/serve_hostname is in contrib/for-demos/serve_hostname
			name := "my-hostname-add-node"
			createServiceWithNameSelector(c, ns, name)
			replicas := testContext.CloudConfig.NumNodes
			createServeHostnameReplicationController(c, ns, name, replicas)
			err := waitForPodsCreatedRunningResponding(c, ns, name, replicas)
			Expect(err).NotTo(HaveOccurred())

			By(fmt.Sprintf("increasing cluster size to %d", replicas+1))
			err = resizeNodeInstanceGroup(replicas + 1)
			Expect(err).NotTo(HaveOccurred())
			err = waitForNodeInstanceGroupSize(replicas + 1)
			Expect(err).NotTo(HaveOccurred())
			err = waitForClusterSize(c, replicas+1)
			Expect(err).NotTo(HaveOccurred())

			By(fmt.Sprintf("increasing size of the replication controller to %d and verifying all pods are running", replicas+1))
			err = resizeReplicationController(c, ns, name, replicas+1)
			Expect(err).NotTo(HaveOccurred())
			err = waitForPodsCreatedRunningResponding(c, ns, name, replicas+1)
			Expect(err).NotTo(HaveOccurred())
		})
	})

	Describe("Network", func() {
		BeforeEach(func() {
			if !providerIs(supportedProviders...) {
				Failf("Nodes.Network test is only supported for providers %v (not %s). You can avoid this failure by using ginkgo.skip=Nodes.Network in your environment.",
					supportedProviders, testContext.Provider)
			}
		})

		// TODO: this test has nothing to do with resizing nodes so it should be moved elsewhere.
		// TODO: two things are tested here:
		// 1. pods from a uncontactable nodes are rescheduled
		// 2. when a node joins the cluster, it can host new pods.
		// Factor out the cases into two separate tests.
		testName = "Uncontactable nodes, have their pods recreated by a replication controller, and can host new pods after rejoining."
		It(testName, func() {
			if testContext.CloudConfig.NumNodes < 2 {
				By(fmt.Sprintf("skipping %s test, which requires at least 2 nodes (not %d)",
					testName, testContext.CloudConfig.NumNodes))
				return
			}

			// Create a replication controller for a service that serves its hostname.
			// The source for the Docker containter kubernetes/serve_hostname is in contrib/for-demos/serve_hostname
			name := "my-hostname-net"
			createServiceWithNameSelector(c, ns, name)
			replicas := testContext.CloudConfig.NumNodes
			createServeHostnameReplicationController(c, ns, name, replicas)
			err := waitForPodsCreatedRunningResponding(c, ns, name, replicas)
			Expect(err).NotTo(HaveOccurred(), "Each pod should start running and responding")

			By("choose a node with at least one pod - we will block some network traffic on this node")
			label := labels.SelectorFromSet(labels.Set(map[string]string{"name": name}))
			pods, err := c.Pods(ns).List(label, fields.Everything()) // list pods after all have been scheduled
			Expect(err).NotTo(HaveOccurred())
			nodeName := pods.Items[0].Spec.NodeName

			node, err := c.Nodes().Get(nodeName)
			Expect(err).NotTo(HaveOccurred())

			By(fmt.Sprintf("block network traffic from node %s", node.Name))
			performTemporaryNetworkFailure(c, ns, name, replicas, pods.Items[0].Name, node)
			Logf("Waiting for node %s to be ready", node.Name)
			waitForNodeToBe(c, node.Name, true, 2*time.Minute)

			By("verify wheter new pods can be created on the re-attached node")
			// increasing the RC size is not a valid way to test this
			// since we have no guarantees the pod will be scheduled on our node.
			additionalPod := "additionalpod"
			err = createServeHostnamePodOnNode(c, ns, additionalPod, node.Name)
			Expect(err).NotTo(HaveOccurred())
			err = waitForPodsCreatedRunningResponding(c, ns, additionalPod, 1)
			Expect(err).NotTo(HaveOccurred())

			// verify that it is really on the requested node
			{
				pod, err := c.Pods(ns).Get(additionalPod)
				Expect(err).NotTo(HaveOccurred())
				if pod.Spec.NodeName != node.Name {
					Logf("Pod %s found on invalid node: %s instead of %s", pod.Spec.NodeName, node.Name)
				}
			}
		})
	})
})