Example #1
0
// UpdateRSWithRetries updates a RS with given applyUpdate function. Note that RS not found error is ignored.
// The returned bool value can be used to tell if the RS is actually updated.
func UpdateRSWithRetries(rsClient unversionedextensions.ReplicaSetInterface, rsLister *cache.StoreToReplicaSetLister, namespace, name string, applyUpdate updateRSFunc) (*extensions.ReplicaSet, error) {
	var rs *extensions.ReplicaSet

	retryErr := retry.RetryOnConflict(retry.DefaultBackoff, func() error {
		var err error
		rs, err = rsLister.ReplicaSets(namespace).Get(name)
		if err != nil {
			return err
		}
		obj, deepCopyErr := api.Scheme.DeepCopy(rs)
		if deepCopyErr != nil {
			return deepCopyErr
		}
		rs = obj.(*extensions.ReplicaSet)
		// Apply the update, then attempt to push it to the apiserver.
		if applyErr := applyUpdate(rs); applyErr != nil {
			return applyErr
		}
		rs, err = rsClient.Update(rs)
		return err
	})

	// Ignore the precondition violated error, but the RS isn't updated.
	if retryErr == errorsutil.ErrPreconditionViolated {
		glog.V(4).Infof("Replica set %s/%s precondition doesn't hold, skip updating it.", namespace, name)
		retryErr = nil
	}

	return rs, retryErr
}
// updateReplicaSetStatus attempts to update the Status.Replicas of the given ReplicaSet, with a single GET/PUT retry.
func updateReplicaSetStatus(c unversionedextensions.ReplicaSetInterface, rs extensions.ReplicaSet, newStatus extensions.ReplicaSetStatus) (updateErr error) {
	// This is the steady state. It happens when the ReplicaSet doesn't have any expectations, since
	// we do a periodic relist every 30s. If the generations differ but the replicas are
	// the same, a caller might've resized to the same replica count.
	if rs.Status.Replicas == newStatus.Replicas &&
		rs.Status.FullyLabeledReplicas == newStatus.FullyLabeledReplicas &&
		rs.Status.ReadyReplicas == newStatus.ReadyReplicas &&
		rs.Status.AvailableReplicas == newStatus.AvailableReplicas &&
		rs.Generation == rs.Status.ObservedGeneration &&
		reflect.DeepEqual(rs.Status.Conditions, newStatus.Conditions) {
		return nil
	}

	// deep copy to avoid mutation now.
	// TODO this method need some work.  Retry on conflict probably, though I suspect this is stomping status to something it probably shouldn't
	copyObj, err := api.Scheme.DeepCopy(&rs)
	if err != nil {
		return err
	}
	rs = *copyObj.(*extensions.ReplicaSet)

	// Save the generation number we acted on, otherwise we might wrongfully indicate
	// that we've seen a spec update when we retry.
	// TODO: This can clobber an update if we allow multiple agents to write to the
	// same status.
	newStatus.ObservedGeneration = rs.Generation

	var getErr error
	for i, rs := 0, &rs; ; i++ {
		glog.V(4).Infof(fmt.Sprintf("Updating replica count for ReplicaSet: %s/%s, ", rs.Namespace, rs.Name) +
			fmt.Sprintf("replicas %d->%d (need %d), ", rs.Status.Replicas, newStatus.Replicas, *(rs.Spec.Replicas)) +
			fmt.Sprintf("fullyLabeledReplicas %d->%d, ", rs.Status.FullyLabeledReplicas, newStatus.FullyLabeledReplicas) +
			fmt.Sprintf("readyReplicas %d->%d, ", rs.Status.ReadyReplicas, newStatus.ReadyReplicas) +
			fmt.Sprintf("availableReplicas %d->%d, ", rs.Status.AvailableReplicas, newStatus.AvailableReplicas) +
			fmt.Sprintf("sequence No: %v->%v", rs.Status.ObservedGeneration, newStatus.ObservedGeneration))

		rs.Status = newStatus
		_, updateErr = c.UpdateStatus(rs)
		if updateErr == nil || i >= statusUpdateRetries {
			return updateErr
		}
		// Update the ReplicaSet with the latest resource version for the next poll
		if rs, getErr = c.Get(rs.Name, metav1.GetOptions{}); getErr != nil {
			// If the GET fails we can't trust status.Replicas anymore. This error
			// is bound to be more interesting than the update failure.
			return getErr
		}
	}
}