Golang integer.IntMax函數代碼示例

func maxContainerRestarts(pod *api.Pod) int {
	maxRestarts := 0
	for _, c := range pod.Status.ContainerStatuses {
		maxRestarts = integer.IntMax(maxRestarts, int(c.RestartCount))
	}
	return maxRestarts
}

// Update all pods for a ReplicationController (oldRc) by creating a new
// controller (newRc) with 0 replicas, and synchronously scaling oldRc and
// newRc until oldRc has 0 replicas and newRc has the original # of desired
// replicas. Cleanup occurs based on a RollingUpdaterCleanupPolicy.
//
// Each interval, the updater will attempt to make progress however it can
// without violating any availability constraints defined by the config. This
// means the amount scaled up or down each interval will vary based on the
// timeliness of readiness and the updater will always try to make progress,
// even slowly.
//
// If an update from newRc to oldRc is already in progress, we attempt to
// drive it to completion. If an error occurs at any step of the update, the
// error will be returned.
//
// A scaling event (either up or down) is considered progress; if no progress
// is made within the config.Timeout, an error is returned.
//
// TODO: make this handle performing a rollback of a partially completed
// rollout.
func (r *RollingUpdater) Update(config *RollingUpdaterConfig) error {
	out := config.Out
	oldRc := config.OldRc
	scaleRetryParams := NewRetryParams(config.Interval, config.Timeout)

	// Find an existing controller (for continuing an interrupted update) or
	// create a new one if necessary.
	sourceId := fmt.Sprintf("%s:%s", oldRc.Name, oldRc.UID)
	newRc, existed, err := r.getOrCreateTargetController(config.NewRc, sourceId)
	if err != nil {
		return err
	}
	if existed {
		fmt.Fprintf(out, "Continuing update with existing controller %s.\n", newRc.Name)
	} else {
		fmt.Fprintf(out, "Created %s\n", newRc.Name)
	}
	// Extract the desired replica count from the controller.
	desiredAnnotation, err := strconv.Atoi(newRc.Annotations[desiredReplicasAnnotation])
	if err != nil {
		return fmt.Errorf("Unable to parse annotation for %s: %s=%s",
			newRc.Name, desiredReplicasAnnotation, newRc.Annotations[desiredReplicasAnnotation])
	}
	desired := int32(desiredAnnotation)
	// Extract the original replica count from the old controller, adding the
	// annotation if it doesn't yet exist.
	_, hasOriginalAnnotation := oldRc.Annotations[originalReplicasAnnotation]
	if !hasOriginalAnnotation {
		existing, err := r.c.ReplicationControllers(oldRc.Namespace).Get(oldRc.Name)
		if err != nil {
			return err
		}
		originReplicas := strconv.Itoa(int(existing.Spec.Replicas))
		applyUpdate := func(rc *api.ReplicationController) {
			if rc.Annotations == nil {
				rc.Annotations = map[string]string{}
			}
			rc.Annotations[originalReplicasAnnotation] = originReplicas
		}
		if oldRc, err = updateRcWithRetries(r.c, existing.Namespace, existing, applyUpdate); err != nil {
			return err
		}
	}
	// maxSurge is the maximum scaling increment and maxUnavailable are the maximum pods
	// that can be unavailable during a rollout.
	maxSurge, maxUnavailable, err := deployment.ResolveFenceposts(&config.MaxSurge, &config.MaxUnavailable, desired)
	if err != nil {
		return err
	}
	// Validate maximums.
	if desired > 0 && maxUnavailable == 0 && maxSurge == 0 {
		return fmt.Errorf("one of maxSurge or maxUnavailable must be specified")
	}
	// The minumum pods which must remain available througout the update
	// calculated for internal convenience.
	minAvailable := int32(integer.IntMax(0, int(desired-maxUnavailable)))
	// If the desired new scale is 0, then the max unavailable is necessarily
	// the effective scale of the old RC regardless of the configuration
	// (equivalent to 100% maxUnavailable).
	if desired == 0 {
		maxUnavailable = oldRc.Spec.Replicas
		minAvailable = 0
	}

	fmt.Fprintf(out, "Scaling up %s from %d to %d, scaling down %s from %d to 0 (keep %d pods available, don't exceed %d pods)\n",
		newRc.Name, newRc.Spec.Replicas, desired, oldRc.Name, oldRc.Spec.Replicas, minAvailable, desired+maxSurge)

	// give a caller incremental notification and allow them to exit early
	goal := desired - newRc.Spec.Replicas
	if goal < 0 {
		goal = -goal
	}
	progress := func(complete bool) error {
		if config.OnProgress == nil {
			return nil
		}
		progress := desired - newRc.Spec.Replicas
		if progress < 0 {
			progress = -progress
		}
//.........這裏部分代碼省略.........

// Update all pods for a ReplicationController (oldRc) by creating a new
// controller (newRc) with 0 replicas, and synchronously scaling oldRc and
// newRc until oldRc has 0 replicas and newRc has the original # of desired
// replicas. Cleanup occurs based on a RollingUpdaterCleanupPolicy.
//
// Each interval, the updater will attempt to make progress however it can
// without violating any availability constraints defined by the config. This
// means the amount scaled up or down each interval will vary based on the
// timeliness of readiness and the updater will always try to make progress,
// even slowly.
//
// If an update from newRc to oldRc is already in progress, we attempt to
// drive it to completion. If an error occurs at any step of the update, the
// error will be returned.
//
// A scaling event (either up or down) is considered progress; if no progress
// is made within the config.Timeout, an error is returned.
//
// TODO: make this handle performing a rollback of a partially completed
// rollout.
func (r *RollingUpdater) Update(config *RollingUpdaterConfig) error {
	out := config.Out
	oldRc := config.OldRc
	scaleRetryParams := NewRetryParams(config.Interval, config.Timeout)

	// Find an existing controller (for continuing an interrupted update) or
	// create a new one if necessary.
	sourceId := fmt.Sprintf("%s:%s", oldRc.Name, oldRc.UID)
	newRc, existed, err := r.getOrCreateTargetController(config.NewRc, sourceId)
	if err != nil {
		return err
	}
	if existed {
		fmt.Fprintf(out, "Continuing update with existing controller %s.\n", newRc.Name)
	} else {
		fmt.Fprintf(out, "Created %s\n", newRc.Name)
	}
	// Extract the desired replica count from the controller.
	desired, err := strconv.Atoi(newRc.Annotations[desiredReplicasAnnotation])
	if err != nil {
		return fmt.Errorf("Unable to parse annotation for %s: %s=%s",
			newRc.Name, desiredReplicasAnnotation, newRc.Annotations[desiredReplicasAnnotation])
	}
	// Extract the original replica count from the old controller, adding the
	// annotation if it doesn't yet exist.
	_, hasOriginalAnnotation := oldRc.Annotations[originalReplicasAnnotation]
	if !hasOriginalAnnotation {
		existing, err := r.c.ReplicationControllers(oldRc.Namespace).Get(oldRc.Name)
		if err != nil {
			return err
		}
		if existing.Annotations == nil {
			existing.Annotations = map[string]string{}
		}
		existing.Annotations[originalReplicasAnnotation] = strconv.Itoa(existing.Spec.Replicas)
		updated, err := r.c.ReplicationControllers(existing.Namespace).Update(existing)
		if err != nil {
			return err
		}
		oldRc = updated
	}
	original, err := strconv.Atoi(oldRc.Annotations[originalReplicasAnnotation])
	if err != nil {
		return fmt.Errorf("Unable to parse annotation for %s: %s=%s\n",
			oldRc.Name, originalReplicasAnnotation, oldRc.Annotations[originalReplicasAnnotation])
	}
	// The maximum pods which can go unavailable during the update.
	maxUnavailable, err := extractMaxValue(config.MaxUnavailable, "maxUnavailable", desired)
	if err != nil {
		return err
	}
	// The maximum scaling increment.
	maxSurge, err := extractMaxValue(config.MaxSurge, "maxSurge", desired)
	if err != nil {
		return err
	}
	// Validate maximums.
	if desired > 0 && maxUnavailable == 0 && maxSurge == 0 {
		return fmt.Errorf("one of maxSurge or maxUnavailable must be specified")
	}
	// The minumum pods which must remain available througout the update
	// calculated for internal convenience.
	minAvailable := integer.IntMax(0, desired-maxUnavailable)
	// If the desired new scale is 0, then the max unavailable is necessarily
	// the effective scale of the old RC regardless of the configuration
	// (equivalent to 100% maxUnavailable).
	if desired == 0 {
		maxUnavailable = original
		minAvailable = 0
	}

	fmt.Fprintf(out, "Scaling up %s from %d to %d, scaling down %s from %d to 0 (keep %d pods available, don't exceed %d pods)\n",
		newRc.Name, newRc.Spec.Replicas, desired, oldRc.Name, oldRc.Spec.Replicas, minAvailable, original+maxSurge)

	// Scale newRc and oldRc until newRc has the desired number of replicas and
	// oldRc has 0 replicas.
	progressDeadline := time.Now().UnixNano() + config.Timeout.Nanoseconds()
	for newRc.Spec.Replicas != desired || oldRc.Spec.Replicas != 0 {
		// Store the existing replica counts for progress timeout tracking.
		newReplicas := newRc.Spec.Replicas
//.........這裏部分代碼省略.........