Golang wait.Poll函數代碼示例

func checkExistingRCRecovers(f Framework) {
	By("assert that the pre-existing replication controller recovers")
	podClient := f.Client.Pods(f.Namespace.Name)
	rcSelector := labels.Set{"name": "baz"}.AsSelector()

	By("deleting pods from existing replication controller")
	expectNoError(wait.Poll(time.Millisecond*500, time.Second*60, func() (bool, error) {
		pods, err := podClient.List(rcSelector, fields.Everything())
		if err != nil {
			Logf("apiserver returned error, as expected before recovery: %v", err)
			return false, nil
		}
		if len(pods.Items) == 0 {
			return false, nil
		}
		for _, pod := range pods.Items {
			err = podClient.Delete(pod.Name, api.NewDeleteOptions(0))
			Expect(err).NotTo(HaveOccurred())
		}
		Logf("apiserver has recovered")
		return true, nil
	}))

	By("waiting for replication controller to recover")
	expectNoError(wait.Poll(time.Millisecond*500, time.Second*60, func() (bool, error) {
		pods, err := podClient.List(rcSelector, fields.Everything())
		Expect(err).NotTo(HaveOccurred())
		for _, pod := range pods.Items {
			if pod.DeletionTimestamp == nil && api.IsPodReady(&pod) {
				return true, nil
			}
		}
		return false, nil
	}))
}

func runSchedulerNoPhantomPodsTest(client *client.Client) {
	pod := &api.Pod{
		Spec: api.PodSpec{
			Containers: []api.Container{
				{
					Name:  "c1",
					Image: "kubernetes/pause",
					Ports: []api.ContainerPort{
						{ContainerPort: 1234, HostPort: 9999},
					},
					ImagePullPolicy: api.PullIfNotPresent,
				},
			},
		},
	}

	// Assuming we only have two kublets, the third pod here won't schedule
	// if the scheduler doesn't correctly handle the delete for the second
	// pod.
	pod.ObjectMeta.Name = "phantom.foo"
	foo, err := client.Pods(api.NamespaceDefault).Create(pod)
	if err != nil {
		glog.Fatalf("Failed to create pod: %v, %v", pod, err)
	}
	if err := wait.Poll(time.Second, time.Second*30, podRunning(client, foo.Namespace, foo.Name)); err != nil {
		glog.Fatalf("FAILED: pod never started running %v", err)
	}

	pod.ObjectMeta.Name = "phantom.bar"
	bar, err := client.Pods(api.NamespaceDefault).Create(pod)
	if err != nil {
		glog.Fatalf("Failed to create pod: %v, %v", pod, err)
	}
	if err := wait.Poll(time.Second, time.Second*30, podRunning(client, bar.Namespace, bar.Name)); err != nil {
		glog.Fatalf("FAILED: pod never started running %v", err)
	}

	// Delete a pod to free up room.
	glog.Infof("Deleting pod %v", bar.Name)
	err = client.Pods(api.NamespaceDefault).Delete(bar.Name, api.NewDeleteOptions(0))
	if err != nil {
		glog.Fatalf("FAILED: couldn't delete pod %q: %v", bar.Name, err)
	}

	pod.ObjectMeta.Name = "phantom.baz"
	baz, err := client.Pods(api.NamespaceDefault).Create(pod)
	if err != nil {
		glog.Fatalf("Failed to create pod: %v, %v", pod, err)
	}
	if err := wait.Poll(time.Second, time.Second*60, podRunning(client, baz.Namespace, baz.Name)); err != nil {
		if pod, perr := client.Pods(api.NamespaceDefault).Get("phantom.bar"); perr == nil {
			glog.Fatalf("FAILED: 'phantom.bar' was never deleted: %#v", pod)
		} else {
			glog.Fatalf("FAILED: (Scheduler probably didn't process deletion of 'phantom.bar') Pod never started running: %v", err)
		}
	}

	glog.Info("Scheduler doesn't make phantom pods: test passed.")
}

// pollForReadyPods polls oldRc and newRc each interval and returns the old
// and new ready counts for their pods. If a pod is observed as being ready,
// it's considered ready even if it later becomes notReady.
func (r *RollingUpdater) pollForReadyPods(interval, timeout time.Duration, oldRc, newRc *api.ReplicationController) (int, int, error) {
	controllers := []*api.ReplicationController{oldRc, newRc}
	oldReady := 0
	newReady := 0
	err := wait.Poll(interval, timeout, func() (done bool, err error) {
		anyReady := false
		for _, controller := range controllers {
			selector := labels.Set(controller.Spec.Selector).AsSelector()
			pods, err := r.c.Pods(controller.Namespace).List(selector, fields.Everything())
			if err != nil {
				return false, err
			}
			for _, pod := range pods.Items {
				if api.IsPodReady(&pod) {
					switch controller.Name {
					case oldRc.Name:
						oldReady++
					case newRc.Name:
						newReady++
					}
					anyReady = true
				}
			}
		}
		if anyReady {
			return true, nil
		}
		return false, nil
	})
	return oldReady, newReady, err
}

// migTemlate (GCE/GKE-only) returns the name of the MIG template that the
// nodes of the cluster use.
func migTemplate() (string, error) {
	var errLast error
	var templ string
	key := "instanceTemplate"
	if wait.Poll(poll, singleCallTimeout, func() (bool, error) {
		// TODO(mikedanese): make this hit the compute API directly instead of
		// shelling out to gcloud.
		// An `instance-groups managed describe` call outputs what we want to stdout.
		output, _, err := retryCmd("gcloud", "compute", "instance-groups", "managed",
			fmt.Sprintf("--project=%s", testContext.CloudConfig.ProjectID),
			"describe",
			fmt.Sprintf("--zone=%s", testContext.CloudConfig.Zone),
			testContext.CloudConfig.NodeInstanceGroup)
		if err != nil {
			errLast = fmt.Errorf("gcloud compute instance-groups managed describe call failed with err: %v", err)
			return false, nil
		}

		// The 'describe' call probably succeeded; parse the output and try to
		// find the line that looks like "instanceTemplate: url/to/<templ>" and
		// return <templ>.
		if val := parseKVLines(output, key); len(val) > 0 {
			url := strings.Split(val, "/")
			templ = url[len(url)-1]
			Logf("MIG group %s using template: %s", testContext.CloudConfig.NodeInstanceGroup, templ)
			return true, nil
		}
		errLast = fmt.Errorf("couldn't find %s in output to get MIG template. Output: %s", key, output)
		return false, nil
	}) != nil {
		return "", fmt.Errorf("migTemplate() failed with last error: %v", errLast)
	}
	return templ, nil
}

// migRollingUpdatePoll (CKE/GKE-only) polls the progress of the MIG rolling
// update with ID id until it is complete. It returns an error if this takes
// longer than nt times the number of nodes.
func migRollingUpdatePoll(id string, nt time.Duration) error {
	// Two keys and a val.
	status, progress, done := "status", "statusMessage", "ROLLED_OUT"
	start, timeout := time.Now(), nt*time.Duration(testContext.CloudConfig.NumNodes)
	var errLast error
	Logf("Waiting up to %v for MIG rolling update to complete.", timeout)
	if wait.Poll(restartPoll, timeout, func() (bool, error) {
		// A `rolling-updates describe` call outputs what we want to stdout.
		output, _, err := retryCmd("gcloud", append(migUdpateCmdBase(),
			"rolling-updates",
			fmt.Sprintf("--project=%s", testContext.CloudConfig.ProjectID),
			fmt.Sprintf("--zone=%s", testContext.CloudConfig.Zone),
			"describe",
			id)...)
		if err != nil {
			errLast = fmt.Errorf("Error calling rolling-updates describe %s: %v", id, err)
			Logf("%v", errLast)
			return false, nil
		}

		// The 'describe' call probably succeeded; parse the output and try to
		// find the line that looks like "status: <status>" and see whether it's
		// done.
		Logf("Waiting for MIG rolling update: %s (%v elapsed)",
			parseKVLines(output, progress), time.Since(start))
		if st := parseKVLines(output, status); st == done {
			return true, nil
		}
		return false, nil
	}) != nil {
		return fmt.Errorf("timeout waiting %v for MIG rolling update to complete. Last error: %v", timeout, errLast)
	}
	Logf("MIG rolling update complete after %v", time.Since(start))
	return nil
}

func assertFilesExist(fileNames []string, fileDir string, pod *api.Pod, client *client.Client) {
	var failed []string

	expectNoError(wait.Poll(time.Second*2, time.Second*60, func() (bool, error) {
		failed = []string{}
		for _, fileName := range fileNames {
			if _, err := client.Get().
				Prefix("proxy").
				Resource("pods").
				Namespace(pod.Namespace).
				Name(pod.Name).
				Suffix(fileDir, fileName).
				Do().Raw(); err != nil {
				Logf("Unable to read %s from pod %s: %v", fileName, pod.Name, err)
				failed = append(failed, fileName)
			}
		}
		if len(failed) == 0 {
			return true, nil
		}
		Logf("Lookups using %s failed for: %v\n", pod.Name, failed)
		return false, nil
	}))
	Expect(len(failed)).To(Equal(0))
}

// Wait till the passFunc confirms that the object it expects to see is in the store.
// Used to observe reflected events.
func waitForReflection(s cache.Store, key string, passFunc func(n interface{}) bool) error {
	return wait.Poll(time.Millisecond*10, time.Second*20, func() (bool, error) {
		if n, _, err := s.GetByKey(key); err == nil && passFunc(n) {
			return true, nil
		}
		return false, nil
	})
}

// Wait for job to reach completions.
func waitForJobFinish(c *client.Client, ns, jobName string, completions int) error {
	return wait.Poll(poll, jobTimeout, func() (bool, error) {
		curr, err := c.Extensions().Jobs(ns).Get(jobName)
		if err != nil {
			return false, err
		}
		return curr.Status.Succeeded == completions, nil
	})
}

func waitForUpToDateCache(cacher *storage.Cacher, resourceVersion uint64) error {
	ready := func() (bool, error) {
		result, err := cacher.LastSyncResourceVersion()
		if err != nil {
			return false, err
		}
		return result == resourceVersion, nil
	}
	return wait.Poll(10*time.Millisecond, util.ForeverTestTimeout, ready)
}

// checkNodesReady waits up to nt for expect nodes accessed by c to be ready,
// returning an error if this doesn't happen in time. It returns the names of
// nodes it finds.
func checkNodesReady(c *client.Client, nt time.Duration, expect int) ([]string, error) {
	// First, keep getting all of the nodes until we get the number we expect.
	var nodeList *api.NodeList
	var errLast error
	start := time.Now()
	found := wait.Poll(poll, nt, func() (bool, error) {
		// Even though listNodes(...) has its own retries, a rolling-update
		// (GCE/GKE implementation of restart) can complete before the apiserver
		// knows about all of the nodes. Thus, we retry the list nodes call
		// until we get the expected number of nodes.
		nodeList, errLast = listNodes(c, labels.Everything(), fields.Everything())
		if errLast != nil {
			return false, nil
		}
		if len(nodeList.Items) != expect {
			errLast = fmt.Errorf("expected to find %d nodes but found only %d (%v elapsed)",
				expect, len(nodeList.Items), time.Since(start))
			Logf("%v", errLast)
			return false, nil
		}
		return true, nil
	}) == nil
	nodeNames := make([]string, len(nodeList.Items))
	for i, n := range nodeList.Items {
		nodeNames[i] = n.ObjectMeta.Name
	}
	if !found {
		return nodeNames, fmt.Errorf("couldn't find %d nodes within %v; last error: %v",
			expect, nt, errLast)
	}
	Logf("Successfully found %d nodes", expect)

	// Next, ensure in parallel that all the nodes are ready. We subtract the
	// time we spent waiting above.
	timeout := nt - time.Since(start)
	result := make(chan bool, len(nodeList.Items))
	for _, n := range nodeNames {
		n := n
		go func() { result <- waitForNodeToBeReady(c, n, timeout) }()
	}
	failed := false
	// TODO(mbforbes): Change to `for range` syntax once we support only Go
	// >= 1.4.
	for i := range nodeList.Items {
		_ = i
		if !<-result {
			failed = true
		}
	}
	if failed {
		return nodeNames, fmt.Errorf("at least one node failed to be ready")
	}
	return nodeNames, nil
}

func (s *ingManager) test(path string) error {
	url := fmt.Sprintf("%v/hostName", path)
	httpClient := &http.Client{}
	return wait.Poll(pollInterval, serviceRespondingTimeout, func() (bool, error) {
		body, err := simpleGET(httpClient, url, "")
		if err != nil {
			Logf("%v\n%v\n%v", url, body, err)
			return false, nil
		}
		return true, nil
	})
}

func getReferencedServiceAccountToken(c *client.Client, ns string, name string, shouldWait bool) (string, string, error) {
	tokenName := ""
	token := ""

	findToken := func() (bool, error) {
		user, err := c.ServiceAccounts(ns).Get(name)
		if errors.IsNotFound(err) {
			return false, nil
		}
		if err != nil {
			return false, err
		}

		for _, ref := range user.Secrets {
			secret, err := c.Secrets(ns).Get(ref.Name)
			if errors.IsNotFound(err) {
				continue
			}
			if err != nil {
				return false, err
			}
			if secret.Type != api.SecretTypeServiceAccountToken {
				continue
			}
			name := secret.Annotations[api.ServiceAccountNameKey]
			uid := secret.Annotations[api.ServiceAccountUIDKey]
			tokenData := secret.Data[api.ServiceAccountTokenKey]
			if name == user.Name && uid == string(user.UID) && len(tokenData) > 0 {
				tokenName = secret.Name
				token = string(tokenData)
				return true, nil
			}
		}

		return false, nil
	}

	if shouldWait {
		err := wait.Poll(time.Second, 10*time.Second, findToken)
		if err != nil {
			return "", "", err
		}
	} else {
		ok, err := findToken()
		if err != nil {
			return "", "", err
		}
		if !ok {
			return "", "", fmt.Errorf("No token found for %s/%s", ns, name)
		}
	}
	return tokenName, token, nil
}

// retryCmd runs cmd using args and retries it for up to singleCallTimeout if
// it returns an error. It returns stdout and stderr.
func retryCmd(command string, args ...string) (string, string, error) {
	var err error
	stdout, stderr := "", ""
	wait.Poll(poll, singleCallTimeout, func() (bool, error) {
		stdout, stderr, err = runCmd(command, args...)
		if err != nil {
			Logf("Got %v", err)
			return false, nil
		}
		return true, nil
	})
	return stdout, stderr, err
}

// Scale updates a Job to a new size, with optional precondition check (if preconditions is not nil),
// optional retries (if retry is not nil), and then optionally waits for parallelism to reach desired
// number, which can be less than requested based on job's current progress.
func (scaler *JobScaler) Scale(namespace, name string, newSize uint, preconditions *ScalePrecondition, retry, waitForReplicas *RetryParams) error {
	if preconditions == nil {
		preconditions = &ScalePrecondition{-1, ""}
	}
	if retry == nil {
		// Make it try only once, immediately
		retry = &RetryParams{Interval: time.Millisecond, Timeout: time.Millisecond}
	}
	cond := ScaleCondition(scaler, preconditions, namespace, name, newSize)
	if err := wait.Poll(retry.Interval, retry.Timeout, cond); err != nil {
		return err
	}
	if waitForReplicas != nil {
		job, err := scaler.c.Extensions().Jobs(namespace).Get(name)
		if err != nil {
			return err
		}
		return wait.Poll(waitForReplicas.Interval, waitForReplicas.Timeout,
			client.JobHasDesiredParallelism(scaler.c, job))
	}
	return nil
}

func (h *haproxyControllerTester) start(namespace string) (err error) {

	// Create a replication controller with the given configuration.
	rc := rcFromManifest(h.cfg)
	rc.Namespace = namespace
	rc.Spec.Template.Labels["rcName"] = rc.Name

	// Add the --namespace arg.
	// TODO: Remove this when we have proper namespace support.
	for i, c := range rc.Spec.Template.Spec.Containers {
		rc.Spec.Template.Spec.Containers[i].Args = append(
			c.Args, fmt.Sprintf("--namespace=%v", namespace))
		Logf("Container args %+v", rc.Spec.Template.Spec.Containers[i].Args)
	}

	rc, err = h.client.ReplicationControllers(rc.Namespace).Create(rc)
	if err != nil {
		return
	}
	if err = waitForRCPodsRunning(h.client, namespace, h.rcName); err != nil {
		return
	}
	h.rcName = rc.Name
	h.rcNamespace = rc.Namespace

	// Find the pods of the rc we just created.
	labelSelector := labels.SelectorFromSet(
		labels.Set(map[string]string{"rcName": h.rcName}))
	pods, err := h.client.Pods(h.rcNamespace).List(
		labelSelector, fields.Everything())
	if err != nil {
		return err
	}

	// Find the external addresses of the nodes the pods are running on.
	for _, p := range pods.Items {
		wait.Poll(pollInterval, serviceRespondingTimeout, func() (bool, error) {
			address, err := getHostExternalAddress(h.client, &p)
			if err != nil {
				Logf("%v", err)
				return false, nil
			}
			h.address = append(h.address, address)
			return true, nil
		})
	}
	if len(h.address) == 0 {
		return fmt.Errorf("No external ips found for loadbalancer %v", h.getName())
	}
	return nil
}