Example #1
// assumes that: caller has acquired scheduler lock and that the task is still pending
func (b *binder) bind(ctx api.Context, binding *api.Binding, task *podtask.T) (err error) {
	// sanity check: ensure that the task hasAcceptedOffer(), it's possible that between
	// Schedule() and now that the offer for this task was rescinded or invalidated.
	// ((we should never see this here))
	if !task.HasAcceptedOffer() {
		return fmt.Errorf("task has not accepted a valid offer %v", task.ID)

	// By this time, there is a chance that the slave is disconnected.
	offerId := task.GetOfferId()
	if offer, ok := b.api.offers().Get(offerId); !ok || offer.HasExpired() {
		// already rescinded or timed out or otherwise invalidated
		return b.rollback(task, fmt.Errorf("failed prior to launchTask due to expired offer for task %v", task.ID))

	if err = b.prepareTaskForLaunch(ctx, binding.Target.Name, task, offerId); err == nil {
		log.V(2).Infof("launching task: %q on target %q slave %q for pod \"%v/%v\"",
			task.ID, binding.Target.Name, task.Spec.SlaveID, task.Pod.Namespace, task.Pod.Name)
		if err = b.api.launchTask(task); err == nil {
			if err = b.api.tasks().Update(task); err != nil {
				// this should only happen if the task has been removed or has changed status,
				// which SHOULD NOT HAPPEN as long as we're synchronizing correctly
				log.Errorf("failed to update task w/ Launched status: %v", err)
	return b.rollback(task, fmt.Errorf("Failed to launch task %v: %v", task.ID, err))