// UpdatePodWithRetries updates a pod with given applyUpdate function. Note that pod not found error is ignored.
// The returned bool value can be used to tell if the pod is actually updated.
func UpdatePodWithRetries(podClient v1core.PodInterface, podLister *cache.StoreToPodLister, namespace, name string, applyUpdate updatePodFunc) (*v1.Pod, error) {
	var pod *v1.Pod

	retryErr := retry.RetryOnConflict(retry.DefaultBackoff, func() error {
		var err error
		pod, err = podLister.Pods(namespace).Get(name)
		if err != nil {
			return err
		}
		obj, deepCopyErr := api.Scheme.DeepCopy(pod)
		if deepCopyErr != nil {
			return deepCopyErr
		}
		pod = obj.(*v1.Pod)
		// Apply the update, then attempt to push it to the apiserver.
		if applyErr := applyUpdate(pod); applyErr != nil {
			return applyErr
		}
		pod, err = podClient.Update(pod)
		return err
	})

	// Ignore the precondition violated error, this pod is already updated
	// with the desired label.
	if retryErr == errorsutil.ErrPreconditionViolated {
		glog.V(4).Infof("Pod %s/%s precondition doesn't hold, skip updating it.", namespace, name)
		retryErr = nil
	}

	return pod, retryErr
}

// WaitForPodToDisappear polls the API server if the pod has been deleted.
func WaitForPodToDisappear(podClient coreclient.PodInterface, podName string, interval, timeout time.Duration) error {
	return wait.PollImmediate(interval, timeout, func() (bool, error) {
		_, err := podClient.Get(podName)
		if err == nil {
			return false, nil
		} else {
			if errors.IsNotFound(err) {
				return true, nil
			} else {
				return false, err
			}
		}
	})
}

// UpdatePodWithRetries updates a pod with given applyUpdate function. Note that pod not found error is ignored.
// The returned bool value can be used to tell if the pod is actually updated.
func UpdatePodWithRetries(podClient v1core.PodInterface, pod *v1.Pod, applyUpdate updatePodFunc) (*v1.Pod, bool, error) {
	var err error
	var podUpdated bool
	oldPod := pod
	if err = wait.Poll(10*time.Millisecond, 1*time.Minute, func() (bool, error) {
		pod, err = podClient.Get(oldPod.Name)
		if err != nil {
			return false, err
		}
		// Apply the update, then attempt to push it to the apiserver.
		if err = applyUpdate(pod); err != nil {
			return false, err
		}
		if pod, err = podClient.Update(pod); err == nil {
			// Update successful.
			return true, nil
		}
		// TODO: don't retry on perm-failed errors and handle them gracefully
		// Update could have failed due to conflict error. Try again.
		return false, nil
	}); err == nil {
		// When there's no error, we've updated this pod.
		podUpdated = true
	}

	// Handle returned error from wait poll
	if err == wait.ErrWaitTimeout {
		err = fmt.Errorf("timed out trying to update pod: %#v", oldPod)
	}
	// Ignore the pod not found error, but the pod isn't updated.
	if errors.IsNotFound(err) {
		glog.V(4).Infof("%s %s/%s is not found, skip updating it.", oldPod.Kind, oldPod.Namespace, oldPod.Name)
		err = nil
	}
	// Ignore the precondition violated error, but the pod isn't updated.
	if err == errorsutil.ErrPreconditionViolated {
		glog.V(4).Infof("%s %s/%s precondition doesn't hold, skip updating it.", oldPod.Kind, oldPod.Namespace, oldPod.Name)
		err = nil
	}

	// If the error is non-nil the returned pod cannot be trusted; if podUpdated is false, the pod isn't updated;
	// if the error is nil and podUpdated is true, the returned pod contains the applied update.
	return pod, podUpdated, err
}

)

const (
	gcePDDetachTimeout  = 10 * time.Minute
	gcePDDetachPollTime = 10 * time.Second
	nodeStatusTimeout   = 1 * time.Minute
	nodeStatusPollTime  = 1 * time.Second
	gcePDRetryTimeout   = 5 * time.Minute
	gcePDRetryPollTime  = 5 * time.Second
	maxReadRetry        = 3
)

var _ = framework.KubeDescribe("Pod Disks", func() {
	var (
		podClient  v1core.PodInterface
		nodeClient v1core.NodeInterface
		host0Name  types.NodeName
		host1Name  types.NodeName
	)
	f := framework.NewDefaultFramework("pod-disks")

	BeforeEach(func() {
		framework.SkipUnlessNodeCountIsAtLeast(2)

		podClient = f.ClientSet.Core().Pods(f.Namespace.Name)
		nodeClient = f.ClientSet.Core().Nodes()
		nodes := framework.GetReadySchedulableNodesOrDie(f.ClientSet)

		Expect(len(nodes.Items)).To(BeNumerically(">=", 2), "Requires at least 2 nodes")

		host0Name = types.NodeName(nodes.Items[0].ObjectMeta.Name)
		host1Name = types.NodeName(nodes.Items[1].ObjectMeta.Name)