func (c *DeploymentConfigController) updateStatus(config *deployapi.DeploymentConfig, deployments []kapi.ReplicationController) error {
	newStatus, err := c.calculateStatus(*config, deployments)
	if err != nil {
		glog.V(2).Infof("Cannot calculate the status for %q: %v", deployutil.LabelForDeploymentConfig(config), err)
		return err
	}

	latestExists, latestRC := deployutil.LatestDeploymentInfo(config, deployments)
	if !latestExists {
		latestRC = nil
	}
	updateConditions(config, &newStatus, latestRC)

	// NOTE: We should update the status of the deployment config only if we need to, otherwise
	// we hotloop between updates.
	if reflect.DeepEqual(newStatus, config.Status) {
		return nil
	}

	copied, err := deployutil.DeploymentConfigDeepCopy(config)
	if err != nil {
		return err
	}

	copied.Status = newStatus
	if _, err := c.dn.DeploymentConfigs(copied.Namespace).UpdateStatus(copied); err != nil {
		glog.V(2).Infof("Cannot update the status for %q: %v", deployutil.LabelForDeploymentConfig(copied), err)
		return err
	}
	glog.V(4).Infof("Updated the status for %q (observed generation: %d)", deployutil.LabelForDeploymentConfig(copied), copied.Status.ObservedGeneration)
	return nil
}

func (c *DeploymentConfigController) calculateStatus(config deployapi.DeploymentConfig, deployments []kapi.ReplicationController, additional ...deployapi.DeploymentCondition) (deployapi.DeploymentConfigStatus, error) {
	selector := labels.Set(config.Spec.Selector).AsSelector()
	// TODO: Replace with using rc.status.availableReplicas that comes with the next rebase.
	pods, err := c.podStore.Pods(config.Namespace).List(selector)
	if err != nil {
		return config.Status, err
	}
	available := deployutil.GetAvailablePods(pods, config.Spec.MinReadySeconds)

	// UpdatedReplicas represents the replicas that use the deployment config template which means
	// we should inform about the replicas of the latest deployment and not the active.
	latestReplicas := int32(0)
	latestExists, latestRC := deployutil.LatestDeploymentInfo(&config, deployments)
	if !latestExists {
		latestRC = nil
	} else {
		latestReplicas = deployutil.GetStatusReplicaCountForDeployments([]kapi.ReplicationController{*latestRC})
	}

	total := deployutil.GetReplicaCountForDeployments(deployments)

	status := deployapi.DeploymentConfigStatus{
		LatestVersion:       config.Status.LatestVersion,
		Details:             config.Status.Details,
		ObservedGeneration:  config.Generation,
		Replicas:            deployutil.GetStatusReplicaCountForDeployments(deployments),
		UpdatedReplicas:     latestReplicas,
		AvailableReplicas:   available,
		UnavailableReplicas: total - available,
		Conditions:          config.Status.Conditions,
	}

	isProgressing := deployutil.IsProgressing(config, status)
	updateConditions(config, &status, latestRC, isProgressing)
	for _, cond := range additional {
		deployutil.SetDeploymentCondition(&status, cond)
	}

	return status, nil
}

func (c *DeploymentConfigController) Handle(config *deployapi.DeploymentConfig) error {
	// There's nothing to reconcile until the version is nonzero.
	if config.Status.LatestVersion == 0 {
		glog.V(5).Infof("Waiting for first version of %q", deployutil.LabelForDeploymentConfig(config))
		return c.updateStatus(config)
	}

	// Find all deployments owned by the deploymentConfig.
	sel := deployutil.ConfigSelector(config.Name)
	existingDeployments, err := c.kubeClient.ReplicationControllers(config.Namespace).List(kapi.ListOptions{LabelSelector: sel})
	if err != nil {
		return err
	}

	latestIsDeployed, latestDeployment := deployutil.LatestDeploymentInfo(config, existingDeployments)
	// If the latest deployment doesn't exist yet, cancel any running
	// deployments to allow them to be superceded by the new config version.
	awaitingCancellations := false
	if !latestIsDeployed {
		for _, deployment := range existingDeployments.Items {
			// Skip deployments with an outcome.
			if deployutil.IsTerminatedDeployment(&deployment) {
				continue
			}
			// Cancel running deployments.
			awaitingCancellations = true
			if !deployutil.IsDeploymentCancelled(&deployment) {
				deployment.Annotations[deployapi.DeploymentCancelledAnnotation] = deployapi.DeploymentCancelledAnnotationValue
				deployment.Annotations[deployapi.DeploymentStatusReasonAnnotation] = deployapi.DeploymentCancelledNewerDeploymentExists
				_, err := c.kubeClient.ReplicationControllers(deployment.Namespace).Update(&deployment)
				if err != nil {
					c.recorder.Eventf(config, kapi.EventTypeWarning, "DeploymentCancellationFailed", "Failed to cancel deployment %q superceded by version %d: %s", deployment.Name, config.Status.LatestVersion, err)
				} else {
					c.recorder.Eventf(config, kapi.EventTypeNormal, "DeploymentCancelled", "Cancelled deployment %q superceded by version %d", deployment.Name, config.Status.LatestVersion)
				}
			}
		}
	}
	// Wait for deployment cancellations before reconciling or creating a new
	// deployment to avoid competing with existing deployment processes.
	if awaitingCancellations {
		c.recorder.Eventf(config, kapi.EventTypeNormal, "DeploymentAwaitingCancellation", "Deployment of version %d awaiting cancellation of older running deployments", config.Status.LatestVersion)
		// raise a transientError so that the deployment config can be re-queued
		return transientError(fmt.Sprintf("found previous inflight deployment for %s - requeuing", deployutil.LabelForDeploymentConfig(config)))
	}
	// If the latest deployment already exists, reconcile existing deployments
	// and return early.
	if latestIsDeployed {
		// If the latest deployment is still running, try again later. We don't
		// want to compete with the deployer.
		if !deployutil.IsTerminatedDeployment(latestDeployment) {
			return c.updateStatus(config)
		}
		return c.reconcileDeployments(existingDeployments, config)
	}
	// No deployments are running and the latest deployment doesn't exist, so
	// create the new deployment.
	deployment, err := deployutil.MakeDeployment(config, c.codec)
	if err != nil {
		return fatalError(fmt.Sprintf("couldn't make deployment from (potentially invalid) deployment config %s: %v", deployutil.LabelForDeploymentConfig(config), err))
	}
	created, err := c.kubeClient.ReplicationControllers(config.Namespace).Create(deployment)
	if err != nil {
		// If the deployment was already created, just move on. The cache could be
		// stale, or another process could have already handled this update.
		if errors.IsAlreadyExists(err) {
			return c.updateStatus(config)
		}
		c.recorder.Eventf(config, kapi.EventTypeWarning, "DeploymentCreationFailed", "Couldn't deploy version %d: %s", config.Status.LatestVersion, err)
		return fmt.Errorf("couldn't create deployment for deployment config %s: %v", deployutil.LabelForDeploymentConfig(config), err)
	}
	c.recorder.Eventf(config, kapi.EventTypeNormal, "DeploymentCreated", "Created new deployment %q for version %d", created.Name, config.Status.LatestVersion)

	return c.updateStatus(config)
}

// reconcileDeployments reconciles existing deployment replica counts which
// could have diverged outside the deployment process (e.g. due to auto or
// manual scaling, or partial deployments). The active deployment is the last
// successful deployment, not necessarily the latest in terms of the config
// version. The active deployment replica count should follow the config, and
// all other deployments should be scaled to zero.
//
// Previously, scaling behavior was that the config replica count was used
// only for initial deployments and the active deployment had to be scaled up
// directly. To continue supporting that old behavior we must detect when the
// deployment has been directly manipulated, and if so, preserve the directly
// updated value and sync the config with the deployment.
func (c *DeploymentConfigController) reconcileDeployments(existingDeployments *kapi.ReplicationControllerList, config *deployapi.DeploymentConfig) error {
	latestIsDeployed, latestDeployment := deployutil.LatestDeploymentInfo(config, existingDeployments)
	if !latestIsDeployed {
		// We shouldn't be reconciling if the latest deployment hasn't been
		// created; this is enforced on the calling side, but double checking
		// can't hurt.
		return nil
	}
	activeDeployment := deployutil.ActiveDeployment(config, existingDeployments)
	// Compute the replica count for the active deployment (even if the active
	// deployment doesn't exist). The active replica count is the value that
	// should be assigned to the config, to allow the replica propagation to
	// flow downward from the config.
	//
	// By default we'll assume the config replicas should be used to update the
	// active deployment except in special cases (like first sync or externally
	// updated deployments.)
	activeReplicas := config.Spec.Replicas
	source := "the deploymentConfig itself (no change)"

	activeDeploymentExists := activeDeployment != nil
	activeDeploymentIsLatest := activeDeploymentExists && activeDeployment.Name == latestDeployment.Name
	latestDesiredReplicas, latestHasDesiredReplicas := deployutil.DeploymentDesiredReplicas(latestDeployment)

	switch {
	case activeDeploymentExists && activeDeploymentIsLatest:
		// The active/latest deployment follows the config unless this is its first
		// sync or if an external change to the deployment replicas is detected.
		lastActiveReplicas, hasLastActiveReplicas := deployutil.DeploymentReplicas(activeDeployment)
		if !hasLastActiveReplicas || lastActiveReplicas != activeDeployment.Spec.Replicas {
			activeReplicas = activeDeployment.Spec.Replicas
			source = fmt.Sprintf("the latest/active deployment %q which was scaled directly or has not previously been synced", deployutil.LabelForDeployment(activeDeployment))
		}
	case activeDeploymentExists && !activeDeploymentIsLatest:
		// The active/non-latest deployment follows the config if it was
		// previously synced; if this is the first sync, infer what the config
		// value should be based on either the latest desired or whatever the
		// deployment is currently scaled to.
		_, hasLastActiveReplicas := deployutil.DeploymentReplicas(activeDeployment)
		if hasLastActiveReplicas {
			break
		}
		if latestHasDesiredReplicas {
			activeReplicas = latestDesiredReplicas
			source = fmt.Sprintf("the desired replicas of latest deployment %q which has not been previously synced", deployutil.LabelForDeployment(latestDeployment))
		} else if activeDeployment.Spec.Replicas > 0 {
			activeReplicas = activeDeployment.Spec.Replicas
			source = fmt.Sprintf("the active deployment %q which has not been previously synced", deployutil.LabelForDeployment(activeDeployment))
		}
	case !activeDeploymentExists && latestHasDesiredReplicas:
		// If there's no active deployment, use the latest desired, if available.
		activeReplicas = latestDesiredReplicas
		source = fmt.Sprintf("the desired replicas of latest deployment %q with no active deployment", deployutil.LabelForDeployment(latestDeployment))
	}

	// Bring the config in sync with the deployment. Once we know the config
	// accurately represents the desired replica count of the active deployment,
	// we can safely reconcile deployments.
	//
	// If the deployment config is test, never update the deployment config based
	// on deployments, since test behavior overrides user scaling.
	switch {
	case config.Spec.Replicas == activeReplicas:
	case config.Spec.Test:
		glog.V(4).Infof("Detected changed replicas for test deploymentConfig %q, ignoring that change", deployutil.LabelForDeploymentConfig(config))
	default:
		oldReplicas := config.Spec.Replicas
		config.Spec.Replicas = activeReplicas
		var err error
		config, err = c.osClient.DeploymentConfigs(config.Namespace).Update(config)
		if err != nil {
			return err
		}
		glog.V(4).Infof("Synced deploymentConfig %q replicas from %d to %d based on %s", deployutil.LabelForDeploymentConfig(config), oldReplicas, activeReplicas, source)
	}

	// Reconcile deployments. The active deployment follows the config, and all
	// other deployments should be scaled to zero.
	for _, deployment := range existingDeployments.Items {
		isActiveDeployment := activeDeployment != nil && deployment.Name == activeDeployment.Name

		oldReplicaCount := deployment.Spec.Replicas
		newReplicaCount := 0
		if isActiveDeployment {
			newReplicaCount = activeReplicas
		}
		if config.Spec.Test {
			glog.V(4).Infof("Deployment config %q is test and deployment %q will be scaled down", deployutil.LabelForDeploymentConfig(config), deployutil.LabelForDeployment(&deployment))
//.........这里部分代码省略.........

// Handle implements the loop that processes deployment configs. Since this controller started
// using caches, the provided config MUST be deep-copied beforehand (see work() in factory.go).
func (c *DeploymentConfigController) Handle(config *deployapi.DeploymentConfig) error {
	// There's nothing to reconcile until the version is nonzero.
	if config.Status.LatestVersion == 0 {
		return c.updateStatus(config, []kapi.ReplicationController{})
	}

	// Find all deployments owned by the deployment config.
	selector := deployutil.ConfigSelector(config.Name)
	existingDeployments, err := c.rcStore.ReplicationControllers(config.Namespace).List(selector)
	if err != nil {
		return err
	}

	// In case the deployment config has been marked for deletion, merely update its status with
	// the latest available information. Some deletions make take some time to complete so there
	// is value in doing this.
	if config.DeletionTimestamp != nil {
		return c.updateStatus(config, existingDeployments)
	}

	latestIsDeployed, latestDeployment := deployutil.LatestDeploymentInfo(config, existingDeployments)
	// If the latest deployment doesn't exist yet, cancel any running
	// deployments to allow them to be superceded by the new config version.
	awaitingCancellations := false
	if !latestIsDeployed {
		for i := range existingDeployments {
			deployment := existingDeployments[i]
			// Skip deployments with an outcome.
			if deployutil.IsTerminatedDeployment(&deployment) {
				continue
			}
			// Cancel running deployments.
			awaitingCancellations = true
			if !deployutil.IsDeploymentCancelled(&deployment) {

				// Retry faster on conflicts
				var updatedDeployment *kapi.ReplicationController
				if err := kclient.RetryOnConflict(kclient.DefaultBackoff, func() error {
					rc, err := c.rcStore.ReplicationControllers(deployment.Namespace).Get(deployment.Name)
					if kapierrors.IsNotFound(err) {
						return nil
					}
					if err != nil {
						return err
					}
					copied, err := deployutil.DeploymentDeepCopy(rc)
					if err != nil {
						return err
					}
					copied.Annotations[deployapi.DeploymentCancelledAnnotation] = deployapi.DeploymentCancelledAnnotationValue
					copied.Annotations[deployapi.DeploymentStatusReasonAnnotation] = deployapi.DeploymentCancelledNewerDeploymentExists
					updatedDeployment, err = c.rn.ReplicationControllers(copied.Namespace).Update(copied)
					return err
				}); err != nil {
					c.recorder.Eventf(config, kapi.EventTypeWarning, "DeploymentCancellationFailed", "Failed to cancel deployment %q superceded by version %d: %s", deployment.Name, config.Status.LatestVersion, err)
				} else {
					if updatedDeployment != nil {
						// replace the current deployment with the updated copy so that a future update has a chance at working
						existingDeployments[i] = *updatedDeployment
						c.recorder.Eventf(config, kapi.EventTypeNormal, "DeploymentCancelled", "Cancelled deployment %q superceded by version %d", deployment.Name, config.Status.LatestVersion)
					}
				}
			}
		}
	}
	// Wait for deployment cancellations before reconciling or creating a new
	// deployment to avoid competing with existing deployment processes.
	if awaitingCancellations {
		c.recorder.Eventf(config, kapi.EventTypeNormal, "DeploymentAwaitingCancellation", "Deployment of version %d awaiting cancellation of older running deployments", config.Status.LatestVersion)
		return fmt.Errorf("found previous inflight deployment for %s - requeuing", deployutil.LabelForDeploymentConfig(config))
	}
	// If the latest deployment already exists, reconcile existing deployments
	// and return early.
	if latestIsDeployed {
		// If the latest deployment is still running, try again later. We don't
		// want to compete with the deployer.
		if !deployutil.IsTerminatedDeployment(latestDeployment) {
			return c.updateStatus(config, existingDeployments)
		}

		return c.reconcileDeployments(existingDeployments, config)
	}
	// If the config is paused we shouldn't create new deployments for it.
	if config.Spec.Paused {
		// in order for revision history limit cleanup to work for paused
		// deployments, we need to trigger it here
		if err := c.cleanupOldDeployments(existingDeployments, config); err != nil {
			c.recorder.Eventf(config, kapi.EventTypeWarning, "DeploymentCleanupFailed", "Couldn't clean up deployments: %v", err)
		}

		return c.updateStatus(config, existingDeployments)
	}
	// No deployments are running and the latest deployment doesn't exist, so
	// create the new deployment.
	deployment, err := deployutil.MakeDeployment(config, c.codec)
	if err != nil {
		return fatalError(fmt.Sprintf("couldn't make deployment from (potentially invalid) deployment config %s: %v", deployutil.LabelForDeploymentConfig(config), err))
	}
//.........这里部分代码省略.........

// reconcileDeployments reconciles existing deployment replica counts which
// could have diverged outside the deployment process (e.g. due to auto or
// manual scaling, or partial deployments). The active deployment is the last
// successful deployment, not necessarily the latest in terms of the config
// version. The active deployment replica count should follow the config, and
// all other deployments should be scaled to zero.
//
// Previously, scaling behavior was that the config replica count was used
// only for initial deployments and the active deployment had to be scaled up
// directly. To continue supporting that old behavior we must detect when the
// deployment has been directly manipulated, and if so, preserve the directly
// updated value and sync the config with the deployment.
func (c *DeploymentConfigController) reconcileDeployments(existingDeployments []kapi.ReplicationController, config *deployapi.DeploymentConfig) error {
	latestIsDeployed, latestDeployment := deployutil.LatestDeploymentInfo(config, existingDeployments)
	if !latestIsDeployed {
		// We shouldn't be reconciling if the latest deployment hasn't been
		// created; this is enforced on the calling side, but double checking
		// can't hurt.
		return c.updateStatus(config, existingDeployments)
	}
	activeDeployment := deployutil.ActiveDeployment(existingDeployments)
	// Compute the replica count for the active deployment (even if the active
	// deployment doesn't exist). The active replica count is the value that
	// should be assigned to the config, to allow the replica propagation to
	// flow downward from the config.
	//
	// By default we'll assume the config replicas should be used to update the
	// active deployment except in special cases (like first sync or externally
	// updated deployments.)
	activeReplicas := config.Spec.Replicas
	source := "the deploymentConfig itself (no change)"

	activeDeploymentExists := activeDeployment != nil
	activeDeploymentIsLatest := activeDeploymentExists && activeDeployment.Name == latestDeployment.Name
	latestDesiredReplicas, latestHasDesiredReplicas := deployutil.DeploymentDesiredReplicas(latestDeployment)

	switch {
	case activeDeploymentExists && activeDeploymentIsLatest:
		// The active/latest deployment follows the config unless this is its first
		// sync or if an external change to the deployment replicas is detected.
		lastActiveReplicas, hasLastActiveReplicas := deployutil.DeploymentReplicas(activeDeployment)
		if !hasLastActiveReplicas || lastActiveReplicas != activeDeployment.Spec.Replicas {
			activeReplicas = activeDeployment.Spec.Replicas
			source = fmt.Sprintf("the latest/active deployment %q which was scaled directly or has not previously been synced", deployutil.LabelForDeployment(activeDeployment))
		}
	case activeDeploymentExists && !activeDeploymentIsLatest:
		// The active/non-latest deployment follows the config if it was
		// previously synced; if this is the first sync, infer what the config
		// value should be based on either the latest desired or whatever the
		// deployment is currently scaled to.
		_, hasLastActiveReplicas := deployutil.DeploymentReplicas(activeDeployment)
		if hasLastActiveReplicas {
			break
		}
		if latestHasDesiredReplicas {
			activeReplicas = latestDesiredReplicas
			source = fmt.Sprintf("the desired replicas of latest deployment %q which has not been previously synced", deployutil.LabelForDeployment(latestDeployment))
		} else if activeDeployment.Spec.Replicas > 0 {
			activeReplicas = activeDeployment.Spec.Replicas
			source = fmt.Sprintf("the active deployment %q which has not been previously synced", deployutil.LabelForDeployment(activeDeployment))
		}
	case !activeDeploymentExists && latestHasDesiredReplicas:
		// If there's no active deployment, use the latest desired, if available.
		activeReplicas = latestDesiredReplicas
		source = fmt.Sprintf("the desired replicas of latest deployment %q with no active deployment", deployutil.LabelForDeployment(latestDeployment))
	}

	// Bring the config in sync with the deployment. Once we know the config
	// accurately represents the desired replica count of the active deployment,
	// we can safely reconcile deployments.
	//
	// If the deployment config is test, never update the deployment config based
	// on deployments, since test behavior overrides user scaling.
	switch {
	case config.Spec.Replicas == activeReplicas:
	case config.Spec.Test:
		glog.V(4).Infof("Detected changed replicas for test deploymentConfig %q, ignoring that change", deployutil.LabelForDeploymentConfig(config))
	default:
		copied, err := deployutil.DeploymentConfigDeepCopy(config)
		if err != nil {
			return err
		}
		oldReplicas := copied.Spec.Replicas
		copied.Spec.Replicas = activeReplicas
		config, err = c.dn.DeploymentConfigs(copied.Namespace).Update(copied)
		if err != nil {
			return err
		}
		glog.V(4).Infof("Synced deploymentConfig %q replicas from %d to %d based on %s", deployutil.LabelForDeploymentConfig(config), oldReplicas, activeReplicas, source)
	}

	// Reconcile deployments. The active deployment follows the config, and all
	// other deployments should be scaled to zero.
	var updatedDeployments []kapi.ReplicationController
	for i := range existingDeployments {
		deployment := existingDeployments[i]
		toAppend := deployment

		isActiveDeployment := activeDeployment != nil && deployment.Name == activeDeployment.Name

//.........这里部分代码省略.........

// reconcileDeployments reconciles existing deployment replica counts which
// could have diverged outside the deployment process (e.g. due to auto or
// manual scaling, or partial deployments). The active deployment is the last
// successful deployment, not necessarily the latest in terms of the config
// version. The active deployment replica count should follow the config, and
// all other deployments should be scaled to zero.
//
// Previously, scaling behavior was that the config replica count was used
// only for initial deployments and the active deployment had to be scaled up
// directly. To continue supporting that old behavior we must detect when the
// deployment has been directly manipulated, and if so, preserve the directly
// updated value and sync the config with the deployment.
func (c *DeploymentConfigController) reconcileDeployments(existingDeployments *kapi.ReplicationControllerList, config *deployapi.DeploymentConfig) error {
	latestIsDeployed, latestDeployment := deployutil.LatestDeploymentInfo(config, existingDeployments)
	if !latestIsDeployed {
		// We shouldn't be reconciling if the latest deployment hasn't been
		// created; this is enforced on the calling side, but double checking
		// can't hurt.
		return nil
	}
	activeDeployment := deployutil.ActiveDeployment(config, existingDeployments)
	// Compute the replica count for the active deployment (even if the active
	// deployment doesn't exist). The active replica count is the value that
	// should be assigned to the config, to allow the replica propagation to
	// flow downward from the config.
	//
	// This takes into account resources predating the propagation behavior
	// change, as well as external modifications to the deployments (e.g.
	// scalers).
	activeReplicas := config.Template.ControllerTemplate.Replicas
	source := "the deploymentConfig itself (no change)"
	if activeDeployment != nil {
		activeDeploymentIsLatest := activeDeployment.Name == latestDeployment.Name
		lastActiveReplicas, hasLastActiveReplicas := deployutil.DeploymentReplicas(activeDeployment)
		if activeDeploymentIsLatest {
			if !hasLastActiveReplicas || lastActiveReplicas != activeDeployment.Spec.Replicas {
				activeReplicas = activeDeployment.Spec.Replicas
				source = fmt.Sprintf("the latest/active deployment %q which was scaled directly or has not previously been synced", deployutil.LabelForDeployment(activeDeployment))
			}
		} else {
			if hasLastActiveReplicas {
				if lastActiveReplicas != activeDeployment.Spec.Replicas && activeDeployment.Spec.Replicas > 0 {
					activeReplicas = activeDeployment.Spec.Replicas
					source = fmt.Sprintf("the active deployment %q which was scaled directly", deployutil.LabelForDeployment(activeDeployment))
				}
			} else {
				if activeDeployment.Spec.Replicas > 0 {
					activeReplicas = activeDeployment.Spec.Replicas
					source = fmt.Sprintf("the active deployment %q which has not been previously synced", deployutil.LabelForDeployment(activeDeployment))
				} else {
					latestDesiredReplicas, latestHasDesiredReplicas := deployutil.DeploymentDesiredReplicas(latestDeployment)
					if latestHasDesiredReplicas {
						activeReplicas = latestDesiredReplicas
						source = fmt.Sprintf("the desired replicas of latest deployment %q which has not been previously synced", deployutil.LabelForDeployment(latestDeployment))
					}
				}
			}
		}
	} else {
		latestDesiredReplicas, latestHasDesiredReplicas := deployutil.DeploymentDesiredReplicas(latestDeployment)
		if latestHasDesiredReplicas {
			activeReplicas = latestDesiredReplicas
			source = fmt.Sprintf("the desired replicas of latest deployment %q with no active deployment", deployutil.LabelForDeployment(latestDeployment))
		}
	}
	// Bring the config in sync with the deployment. Once we know the config
	// accurately represents the desired replica count of the active deployment,
	// we can safely reconcile deployments.
	if config.Template.ControllerTemplate.Replicas != activeReplicas {
		oldReplicas := config.Template.ControllerTemplate.Replicas
		config.Template.ControllerTemplate.Replicas = activeReplicas
		_, err := c.osClient.DeploymentConfigs(config.Namespace).Update(config)
		if err != nil {
			return err
		}
		glog.V(4).Infof("Synced deploymentConfig %q replicas from %d to %d based on %s", deployutil.LabelForDeploymentConfig(config), oldReplicas, activeReplicas, source)
	}
	// Reconcile deployments. The active deployment follows the config, and all
	// other deployments should be scaled to zero.
	for _, deployment := range existingDeployments.Items {
		isActiveDeployment := activeDeployment != nil && deployment.Name == activeDeployment.Name

		oldReplicaCount := deployment.Spec.Replicas
		newReplicaCount := 0
		if isActiveDeployment {
			newReplicaCount = activeReplicas
		}
		lastReplicas, hasLastReplicas := deployutil.DeploymentReplicas(&deployment)
		// Only update if necessary.
		if !hasLastReplicas || newReplicaCount != oldReplicaCount || lastReplicas != newReplicaCount {
			deployment.Spec.Replicas = newReplicaCount
			deployment.Annotations[deployapi.DeploymentReplicasAnnotation] = strconv.Itoa(newReplicaCount)
			_, err := c.kubeClient.ReplicationControllers(deployment.Namespace).Update(&deployment)
			if err != nil {
				c.recorder.Eventf(config, "DeploymentScaleFailed",
					"Failed to scale deployment %q from %d to %d: %s", deployment.Name, oldReplicaCount, newReplicaCount, err)
				return err
			}
			// Only report scaling events if we changed the replica count.
			if oldReplicaCount != newReplicaCount {
//.........这里部分代码省略.........

// findDetails inspects the given deployment configuration for any failure causes
// and returns any found details about it
func (c *DeploymentConfigController) findDetails(config *deployapi.DeploymentConfig) (string, *kapi.ReplicationControllerList, bool, error) {
	// Check if any existing inflight deployments (any non-terminal state).
	existingDeployments, err := c.deploymentClient.listDeploymentsForConfig(config.Namespace, config.Name)
	if err != nil {
		return "", nil, false, fmt.Errorf("couldn't list deployments for deployment config %q: %v", deployutil.LabelForDeploymentConfig(config), err)
	}
	// check if the latest deployment exists
	// we'll return after we've dealt with the multiple-active-deployments case
	latestDeploymentExists, latestDeploymentStatus := deployutil.LatestDeploymentInfo(config, existingDeployments)
	if latestDeploymentExists && latestDeploymentStatus != deployapi.DeploymentStatusFailed {
		// If the latest deployment exists and is not failed, clear the dc message
		return "", existingDeployments, latestDeploymentExists, nil
	}

	// Rest of the code will handle non-existing or failed latest deployment causes
	// TODO: Inspect pod logs in case of failed latest

	details := ""
	allDetails := []string{}
	if config.Details != nil && len(config.Details.Message) > 0 {
		// Populate details with the previous message so that in case we stumble upon
		// an unexpected client error, the message won't be overwritten
		details = config.Details.Message
	}
	// Look into image change triggers and find out possible deployment failures such as
	// missing image stream tags with or without build configurations pointing at them
	for _, trigger := range config.Triggers {
		if trigger.Type != deployapi.DeploymentTriggerOnImageChange || trigger.ImageChangeParams == nil || !trigger.ImageChangeParams.Automatic {
			continue
		}
		name := trigger.ImageChangeParams.From.Name
		tag := trigger.ImageChangeParams.Tag
		istag := imageapi.JoinImageStreamTag(name, tag)

		// Check if the image stream tag pointed by the trigger exists
		if _, err := c.osClient.ImageStreamTags(config.Namespace).Get(name, tag); err != nil {
			if !errors.IsNotFound(err) {
				glog.V(2).Infof("Error while trying to get image stream tag %q: %v", istag, err)
				return details, existingDeployments, latestDeploymentExists, nil
			}
			// In case the image stream tag was not found, then it either doesn't exist or doesn't exist yet
			// (a build configuration output points to it so it's going to be populated at some point in the
			// future)
			details = fmt.Sprintf("The image trigger for image stream tag %q will have no effect because image stream tag %q does not exist.", istag, istag)
			bcList, err := c.osClient.BuildConfigs(kapi.NamespaceAll).List(labels.Everything(), fields.Everything())
			if err != nil {
				glog.V(2).Infof("Error while trying to list build configs: %v", err)
				return details, existingDeployments, latestDeploymentExists, nil
			}

			for _, bc := range bcList.Items {
				if bc.Spec.Output.To != nil && bc.Spec.Output.To.Kind == "ImageStreamTag" {
					parts := strings.Split(bc.Spec.Output.To.Name, ":")
					if len(parts) != 2 {
						glog.V(2).Infof("Invalid image stream tag: %q", bc.Spec.Output.To.Name)
						return details, existingDeployments, latestDeploymentExists, nil
					}
					if parts[0] == name && parts[1] == tag {
						details = fmt.Sprintf("The image trigger for image stream tag %q will have no effect because image stream tag %q does not exist.\n\tIf image stream tag %q is expected, check build config %q which produces image stream tag %q.", istag, istag, istag, bc.Name, istag)
						break
					}
				}
			}
			// Try to see if the image stream exists, if not then the build will never be able to update the
			// tag in question
			if _, err := c.osClient.ImageStreams(config.Namespace).Get(name); err != nil {
				glog.V(2).Infof("Error while trying to get image stream %q: %v", name, err)
				if errors.IsNotFound(err) {
					details = fmt.Sprintf("The image trigger for image stream tag %q will have no effect because image stream %q does not exist.", istag, name)
				}
			}
		}
		allDetails = append(allDetails, details)
	}

	if len(allDetails) > 1 {
		for i := range allDetails {
			allDetails[i] = fmt.Sprintf("\t* %s", allDetails[i])
		}
		// Prepend multiple errors warning
		multipleErrWarning := fmt.Sprintf("Deployment config %q blocked by multiple errors:\n", config.Name)
		allDetails = append([]string{multipleErrWarning}, allDetails...)
	}

	return strings.Join(allDetails, "\n"), existingDeployments, latestDeploymentExists, nil
}

// Handle processes config and creates a new deployment if necessary.
func (c *DeploymentConfigController) Handle(config *deployapi.DeploymentConfig) error {
	// TODO(danmace): Don't use findDetails yet. See: https://github.com/openshift/origin/pull/5530

	// Only deploy when the version has advanced past 0.
	if config.LatestVersion == 0 {
		glog.V(5).Infof("Waiting for first version of %s", deployutil.LabelForDeploymentConfig(config))
		return nil
	}

	existingDeployments, err := c.deploymentClient.listDeploymentsForConfig(config.Namespace, config.Name)
	if err != nil {
		return err
	}

	var inflightDeployment *kapi.ReplicationController
	for _, deployment := range existingDeployments.Items {

		deploymentStatus := deployutil.DeploymentStatusFor(&deployment)
		switch deploymentStatus {
		case deployapi.DeploymentStatusFailed,
			deployapi.DeploymentStatusComplete:
			// Previous deployment in terminal state - can ignore
			// Ignoring specific deployment states so that any newly introduced
			// deployment state will not be ignored
		default:
			if inflightDeployment == nil {
				inflightDeployment = &deployment
				continue
			}
			var deploymentForCancellation *kapi.ReplicationController
			if deployutil.DeploymentVersionFor(inflightDeployment) < deployutil.DeploymentVersionFor(&deployment) {
				deploymentForCancellation, inflightDeployment = inflightDeployment, &deployment
			} else {
				deploymentForCancellation = &deployment
			}

			deploymentForCancellation.Annotations[deployapi.DeploymentCancelledAnnotation] = deployapi.DeploymentCancelledAnnotationValue
			deploymentForCancellation.Annotations[deployapi.DeploymentStatusReasonAnnotation] = deployapi.DeploymentCancelledNewerDeploymentExists
			if _, err := c.deploymentClient.updateDeployment(deploymentForCancellation.Namespace, deploymentForCancellation); err != nil {
				util.HandleError(fmt.Errorf("couldn't cancel deployment %s: %v", deployutil.LabelForDeployment(deploymentForCancellation), err))
			}
			glog.V(4).Infof("Cancelled deployment %s for deployment config %s", deployutil.LabelForDeployment(deploymentForCancellation), deployutil.LabelForDeploymentConfig(config))
		}
	}

	// if the latest deployment exists then nothing else needs to be done
	latestDeploymentExists, _ := deployutil.LatestDeploymentInfo(config, existingDeployments)
	if latestDeploymentExists {
		return nil
	}

	// check to see if there are inflight deployments
	if inflightDeployment != nil {
		// raise a transientError so that the deployment config can be re-queued
		glog.V(4).Infof("Found previous inflight deployment for %s - will requeue", deployutil.LabelForDeploymentConfig(config))
		return transientError(fmt.Sprintf("found previous inflight deployment for %s - requeuing", deployutil.LabelForDeploymentConfig(config)))
	}

	// Try and build a deployment for the config.
	deployment, err := c.makeDeployment(config)
	if err != nil {
		return fatalError(fmt.Sprintf("couldn't make deployment from (potentially invalid) deployment config %s: %v", deployutil.LabelForDeploymentConfig(config), err))
	}

	// Compute the desired replicas for the deployment. Use the last completed
	// deployment's current replica count, or the config template if there is no
	// prior completed deployment available.
	desiredReplicas := config.Template.ControllerTemplate.Replicas
	if len(existingDeployments.Items) > 0 {
		sort.Sort(deployutil.ByLatestVersionDesc(existingDeployments.Items))
		for _, existing := range existingDeployments.Items {
			if deployutil.DeploymentStatusFor(&existing) == deployapi.DeploymentStatusComplete {
				desiredReplicas = existing.Spec.Replicas
				glog.V(4).Infof("Desired replicas for %s set to %d based on prior completed deployment %s", deployutil.LabelForDeploymentConfig(config), desiredReplicas, existing.Name)
				break
			}
		}
	}
	deployment.Annotations[deployapi.DesiredReplicasAnnotation] = strconv.Itoa(desiredReplicas)

	// Create the deployment.
	if _, err := c.deploymentClient.createDeployment(config.Namespace, deployment); err == nil {
		glog.V(4).Infof("Created deployment for deployment config %s", deployutil.LabelForDeploymentConfig(config))
		return nil
	} else {
		// If the deployment was already created, just move on. The cache could be stale, or another
		// process could have already handled this update.
		if errors.IsAlreadyExists(err) {
			glog.V(4).Infof("Deployment already exists for deployment config %s", deployutil.LabelForDeploymentConfig(config))
			return nil
		}

		glog.Warningf("Cannot create latest deployment for deployment config %q: %v", deployutil.LabelForDeploymentConfig(config), err)
		return fmt.Errorf("couldn't create deployment for deployment config %s: %v", deployutil.LabelForDeploymentConfig(config), err)
	}
}