Пример #1
0
func (e *quotaEvaluator) Evaluate(a admission.Attributes) error {
	e.init.Do(func() {
		go e.run()
	})

	// if we do not know how to evaluate use for this kind, just ignore
	evaluators := e.registry.Evaluators()
	evaluator, found := evaluators[a.GetKind().GroupKind()]
	if !found {
		return nil
	}
	// for this kind, check if the operation could mutate any quota resources
	// if no resources tracked by quota are impacted, then just return
	op := a.GetOperation()
	if !evaluator.Handles(op) {
		return nil
	}

	waiter := newAdmissionWaiter(a)

	e.addWork(waiter)

	// wait for completion or timeout
	select {
	case <-waiter.finished:
	case <-time.After(10 * time.Second):
		return fmt.Errorf("timeout")
	}

	return waiter.result
}
Пример #2
0
// Admit admits resources into cluster that do not violate any defined LimitRange in the namespace
func (l *limitRanger) Admit(a admission.Attributes) (err error) {
	if !l.actions.SupportsAttributes(a) {
		return nil
	}

	obj := a.GetObject()
	name := "Unknown"
	if obj != nil {
		name, _ = meta.NewAccessor().Name(obj)
		if len(name) == 0 {
			name, _ = meta.NewAccessor().GenerateName(obj)
		}
	}

	items, err := l.lister.LimitRanges(a.GetNamespace()).List(labels.Everything())
	if err != nil {
		return admission.NewForbidden(a, fmt.Errorf("unable to %s %v at this time because there was an error enforcing limit ranges", a.GetOperation(), a.GetResource()))
	}

	// if there are no items held in our indexer, check our live-lookup LRU, if that misses, do the live lookup to prime it.
	if len(items) == 0 {
		lruItemObj, ok := l.liveLookupCache.Get(a.GetNamespace())
		if !ok || lruItemObj.(liveLookupEntry).expiry.Before(time.Now()) {
			// TODO: If there are multiple operations at the same time and cache has just expired,
			// this may cause multiple List operations being issued at the same time.
			// If there is already in-flight List() for a given namespace, we should wait until
			// it is finished and cache is updated instead of doing the same, also to avoid
			// throttling - see #22422 for details.
			liveList, err := l.client.Core().LimitRanges(a.GetNamespace()).List(api.ListOptions{})
			if err != nil {
				return admission.NewForbidden(a, err)
			}
			newEntry := liveLookupEntry{expiry: time.Now().Add(l.liveTTL)}
			for i := range liveList.Items {
				newEntry.items = append(newEntry.items, &liveList.Items[i])
			}
			l.liveLookupCache.Add(a.GetNamespace(), newEntry)
			lruItemObj = newEntry
		}
		lruEntry := lruItemObj.(liveLookupEntry)

		for i := range lruEntry.items {
			items = append(items, lruEntry.items[i])
		}

	}

	// ensure it meets each prescribed min/max
	for i := range items {
		limitRange := items[i]

		if !l.actions.SupportsLimit(limitRange) {
			continue
		}

		err = l.actions.Limit(limitRange, a.GetResource().Resource, a.GetObject())
		if err != nil {
			return admission.NewForbidden(a, err)
		}
	}
	return nil
}
Пример #3
0
// checkRequest verifies that the request does not exceed any quota constraint. it returns a copy of quotas not yet persisted
// that capture what the usage would be if the request succeeded.  It return an error if the is insufficient quota to satisfy the request
func (e *quotaEvaluator) checkRequest(quotas []api.ResourceQuota, a admission.Attributes) ([]api.ResourceQuota, error) {
	namespace := a.GetNamespace()
	evaluators := e.registry.Evaluators()
	evaluator, found := evaluators[a.GetKind().GroupKind()]
	if !found {
		return quotas, nil
	}

	op := a.GetOperation()
	if !evaluator.Handles(op) {
		return quotas, nil
	}

	// find the set of quotas that are pertinent to this request
	// reject if we match the quota, but usage is not calculated yet
	// reject if the input object does not satisfy quota constraints
	// if there are no pertinent quotas, we can just return
	inputObject := a.GetObject()
	interestingQuotaIndexes := []int{}
	for i := range quotas {
		resourceQuota := quotas[i]
		match, err := evaluator.Matches(&resourceQuota, inputObject)
		if err != nil {
			return quotas, err
		}
		if !match {
			continue
		}

		hardResources := quota.ResourceNames(resourceQuota.Status.Hard)
		requiredResources := evaluator.MatchingResources(hardResources)
		if err := evaluator.Constraints(requiredResources, inputObject); err != nil {
			return nil, admission.NewForbidden(a, fmt.Errorf("failed quota: %s: %v", resourceQuota.Name, err))
		}
		if !hasUsageStats(&resourceQuota) {
			return nil, admission.NewForbidden(a, fmt.Errorf("status unknown for quota: %s", resourceQuota.Name))
		}

		interestingQuotaIndexes = append(interestingQuotaIndexes, i)
	}
	if len(interestingQuotaIndexes) == 0 {
		return quotas, nil
	}

	// Usage of some resources cannot be counted in isolation. For example, when
	// the resource represents a number of unique references to external
	// resource. In such a case an evaluator needs to process other objects in
	// the same namespace which needs to be known.
	if accessor, err := meta.Accessor(inputObject); namespace != "" && err == nil {
		if accessor.GetNamespace() == "" {
			accessor.SetNamespace(namespace)
		}
	}

	// there is at least one quota that definitely matches our object
	// as a result, we need to measure the usage of this object for quota
	// on updates, we need to subtract the previous measured usage
	// if usage shows no change, just return since it has no impact on quota
	deltaUsage, err := evaluator.Usage(inputObject)
	if err != nil {
		return quotas, err
	}

	// ensure that usage for input object is never negative (this would mean a resource made a negative resource requirement)
	if negativeUsage := quota.IsNegative(deltaUsage); len(negativeUsage) > 0 {
		return nil, admission.NewForbidden(a, fmt.Errorf("quota usage is negative for resource(s): %s", prettyPrintResourceNames(negativeUsage)))
	}

	if admission.Update == op {
		prevItem := a.GetOldObject()
		if prevItem == nil {
			return nil, admission.NewForbidden(a, fmt.Errorf("unable to get previous usage since prior version of object was not found"))
		}

		// if we can definitively determine that this is not a case of "create on update",
		// then charge based on the delta.  Otherwise, bill the maximum
		metadata, err := meta.Accessor(prevItem)
		if err == nil && len(metadata.GetResourceVersion()) > 0 {
			prevUsage, innerErr := evaluator.Usage(prevItem)
			if innerErr != nil {
				return quotas, innerErr
			}
			deltaUsage = quota.Subtract(deltaUsage, prevUsage)
		}
	}
	if quota.IsZero(deltaUsage) {
		return quotas, nil
	}

	outQuotas, err := copyQuotas(quotas)
	if err != nil {
		return nil, err
	}

	for _, index := range interestingQuotaIndexes {
		resourceQuota := outQuotas[index]

		hardResources := quota.ResourceNames(resourceQuota.Status.Hard)
		requestedUsage := quota.Mask(deltaUsage, hardResources)
		newUsage := quota.Add(resourceQuota.Status.Used, requestedUsage)
		maskedNewUsage := quota.Mask(newUsage, quota.ResourceNames(requestedUsage))

		if allowed, exceeded := quota.LessThanOrEqual(maskedNewUsage, resourceQuota.Status.Hard); !allowed {
			failedRequestedUsage := quota.Mask(requestedUsage, exceeded)
			failedUsed := quota.Mask(resourceQuota.Status.Used, exceeded)
			failedHard := quota.Mask(resourceQuota.Status.Hard, exceeded)
			return nil, admission.NewForbidden(a,
				fmt.Errorf("exceeded quota: %s, requested: %s, used: %s, limited: %s",
					resourceQuota.Name,
					prettyPrint(failedRequestedUsage),
					prettyPrint(failedUsed),
					prettyPrint(failedHard)))
		}

		// update to the new usage number
		outQuotas[index].Status.Used = newUsage
	}

	return outQuotas, nil
}
Пример #4
0
func (l *lifecycle) Admit(a admission.Attributes) error {
	// prevent deletion of immortal namespaces
	if a.GetOperation() == admission.Delete && a.GetKind().GroupKind() == api.Kind("Namespace") && l.immortalNamespaces.Has(a.GetName()) {
		return errors.NewForbidden(a.GetResource().GroupResource(), a.GetName(), fmt.Errorf("this namespace may not be deleted"))
	}

	// if we're here, then we've already passed authentication, so we're allowed to do what we're trying to do
	// if we're here, then the API server has found a route, which means that if we have a non-empty namespace
	// its a namespaced resource.
	if len(a.GetNamespace()) == 0 || a.GetKind().GroupKind() == api.Kind("Namespace") {
		// if a namespace is deleted, we want to prevent all further creates into it
		// while it is undergoing termination.  to reduce incidences where the cache
		// is slow to update, we add the namespace into a force live lookup list to ensure
		// we are not looking at stale state.
		if a.GetOperation() == admission.Delete {
			l.forceLiveLookupCache.Add(a.GetName(), true, forceLiveLookupTTL)
		}
		return nil
	}

	// we need to wait for our caches to warm
	if !l.WaitForReady() {
		return admission.NewForbidden(a, fmt.Errorf("not yet ready to handle request"))
	}

	var (
		namespaceObj interface{}
		exists       bool
		err          error
	)

	key := makeNamespaceKey(a.GetNamespace())
	namespaceObj, exists, err = l.namespaceInformer.GetStore().Get(key)
	if err != nil {
		return errors.NewInternalError(err)
	}

	if !exists && a.GetOperation() == admission.Create {
		// give the cache time to observe the namespace before rejecting a create.
		// this helps when creating a namespace and immediately creating objects within it.
		time.Sleep(missingNamespaceWait)
		namespaceObj, exists, err = l.namespaceInformer.GetStore().Get(key)
		if err != nil {
			return errors.NewInternalError(err)
		}
		if exists {
			glog.V(4).Infof("found %s in cache after waiting", a.GetNamespace())
		}
	}

	// forceLiveLookup if true will skip looking at local cache state and instead always make a live call to server.
	forceLiveLookup := false
	if _, ok := l.forceLiveLookupCache.Get(a.GetNamespace()); ok {
		// we think the namespace was marked for deletion, but our current local cache says otherwise, we will force a live lookup.
		forceLiveLookup = exists && namespaceObj.(*api.Namespace).Status.Phase == api.NamespaceActive
	}

	// refuse to operate on non-existent namespaces
	if !exists || forceLiveLookup {
		// as a last resort, make a call directly to storage
		namespaceObj, err = l.client.Core().Namespaces().Get(a.GetNamespace(), metav1.GetOptions{})
		if err != nil {
			if errors.IsNotFound(err) {
				return err
			}
			return errors.NewInternalError(err)
		}
		glog.V(4).Infof("found %s via storage lookup", a.GetNamespace())
	}

	// ensure that we're not trying to create objects in terminating namespaces
	if a.GetOperation() == admission.Create {
		namespace := namespaceObj.(*api.Namespace)
		if namespace.Status.Phase != api.NamespaceTerminating {
			return nil
		}

		// TODO: This should probably not be a 403
		return admission.NewForbidden(a, fmt.Errorf("unable to create new content in namespace %s because it is being terminated.", a.GetNamespace()))
	}

	return nil
}