Example #1
0
// Call ScheduleFunc and subtract some resources, returning the name of the machine the task is scheduled on
func (k *kubeScheduler) doSchedule(task *podtask.T, err error) (string, error) {
	var offer offers.Perishable
	if task.HasAcceptedOffer() {
		// verify that the offer is still on the table
		offerId := task.GetOfferId()
		if offer, ok := k.api.offers().Get(offerId); ok && !offer.HasExpired() {
			// skip tasks that have already have assigned offers
			offer = task.Offer
		} else {
			task.Offer.Release()
			task.Reset()
			if err = k.api.tasks().Update(task); err != nil {
				return "", err
			}
		}
	}
	if err == nil && offer == nil {
		offer, err = k.api.algorithm().SchedulePod(k.api.offers(), k.api, task)
	}
	if err != nil {
		return "", err
	}
	details := offer.Details()
	if details == nil {
		return "", fmt.Errorf("offer already invalid/expired for task %v", task.ID)
	}
	slaveId := details.GetSlaveId().GetValue()
	if slaveHostName := k.api.slaveHostNameFor(slaveId); slaveHostName == "" {
		// not much sense in Release()ing the offer here since its owner died
		offer.Release()
		k.api.offers().Invalidate(details.Id.GetValue())
		return "", fmt.Errorf("Slave disappeared (%v) while scheduling task %v", slaveId, task.ID)
	} else {
		if task.Offer != nil && task.Offer != offer {
			return "", fmt.Errorf("task.offer assignment must be idempotent, task %+v: offer %+v", task, offer)
		}

		task.Offer = offer
		k.api.algorithm().Procurement()(task, details) // TODO(jdef) why is nothing checking the error returned here?

		if err := k.api.tasks().Update(task); err != nil {
			offer.Release()
			return "", err
		}
		return slaveHostName, nil
	}
}