Exemple #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
}
Exemple #2
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// SupportsAttributes ignores all calls that do not deal with pod resources or storage requests (PVCs).
// Also ignores any call that has a subresource defined.
func (d *DefaultLimitRangerActions) SupportsAttributes(a admission.Attributes) bool {
	if a.GetSubresource() != "" {
		return false
	}

	return a.GetKind().GroupKind() == api.Kind("Pod") || a.GetKind().GroupKind() == api.Kind("PersistentVolumeClaim")
}
Exemple #3
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func (p *provision) Admit(a admission.Attributes) (err error) {
	// 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") {
		return nil
	}
	// we need to wait for our caches to warm
	if !p.WaitForReady() {
		return admission.NewForbidden(a, fmt.Errorf("not yet ready to handle request"))
	}
	namespace := &api.Namespace{
		ObjectMeta: metav1.ObjectMeta{
			Name:      a.GetNamespace(),
			Namespace: "",
		},
		Status: api.NamespaceStatus{},
	}
	_, exists, err := p.namespaceInformer.GetStore().Get(namespace)
	if err != nil {
		return admission.NewForbidden(a, err)
	}
	if exists {
		return nil
	}
	_, err = p.client.Core().Namespaces().Create(namespace)
	if err != nil && !errors.IsAlreadyExists(err) {
		return admission.NewForbidden(a, err)
	}
	return nil
}
Exemple #4
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func (e *exists) Admit(a admission.Attributes) (err error) {
	// 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") {
		return nil
	}

	// we need to wait for our caches to warm
	if !e.WaitForReady() {
		return admission.NewForbidden(a, fmt.Errorf("not yet ready to handle request"))
	}
	namespace := &api.Namespace{
		ObjectMeta: metav1.ObjectMeta{
			Name:      a.GetNamespace(),
			Namespace: "",
		},
		Status: api.NamespaceStatus{},
	}
	_, exists, err := e.namespaceInformer.GetStore().Get(namespace)
	if err != nil {
		return errors.NewInternalError(err)
	}
	if exists {
		return nil
	}

	// in case of latency in our caches, make a call direct to storage to verify that it truly exists or not
	_, err = e.client.Core().Namespaces().Get(a.GetNamespace(), metav1.GetOptions{})
	if err != nil {
		if errors.IsNotFound(err) {
			return err
		}
		return errors.NewInternalError(err)
	}

	return nil
}
Exemple #5
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// 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
}
Exemple #6
0
// Admit enforces that pod and its namespace node label selectors matches at least a node in the cluster.
func (p *podNodeSelector) Admit(a admission.Attributes) error {
	resource := a.GetResource().GroupResource()
	if resource != api.Resource("pods") {
		return nil
	}
	if a.GetSubresource() != "" {
		// only run the checks below on pods proper and not subresources
		return nil
	}

	obj := a.GetObject()
	pod, ok := obj.(*api.Pod)
	if !ok {
		glog.Errorf("expected pod but got %s", a.GetKind().Kind)
		return nil
	}

	if !p.WaitForReady() {
		return admission.NewForbidden(a, fmt.Errorf("not yet ready to handle request"))
	}

	name := pod.Name
	nsName := a.GetNamespace()
	var namespace *api.Namespace

	namespaceObj, exists, err := p.namespaceInformer.GetStore().Get(&api.Namespace{
		ObjectMeta: metav1.ObjectMeta{
			Name:      nsName,
			Namespace: "",
		},
	})
	if err != nil {
		return errors.NewInternalError(err)
	}
	if exists {
		namespace = namespaceObj.(*api.Namespace)
	} else {
		namespace, err = p.defaultGetNamespace(nsName)
		if err != nil {
			if errors.IsNotFound(err) {
				return err
			}
			return errors.NewInternalError(err)
		}
	}
	namespaceNodeSelector, err := p.getNodeSelectorMap(namespace)
	if err != nil {
		return err
	}

	if labels.Conflicts(namespaceNodeSelector, labels.Set(pod.Spec.NodeSelector)) {
		return errors.NewForbidden(resource, name, fmt.Errorf("pod node label selector conflicts with its namespace node label selector"))
	}

	whitelist, err := labels.ConvertSelectorToLabelsMap(p.clusterNodeSelectors[namespace.Name])
	if err != nil {
		return err
	}

	// Merge pod node selector = namespace node selector + current pod node selector
	podNodeSelectorLabels := labels.Merge(namespaceNodeSelector, pod.Spec.NodeSelector)

	// whitelist verification
	if !labels.AreLabelsInWhiteList(podNodeSelectorLabels, whitelist) {
		return errors.NewForbidden(resource, name, fmt.Errorf("pod node label selector labels conflict with its namespace whitelist"))
	}

	// Updated pod node selector = namespace node selector + current pod node selector
	pod.Spec.NodeSelector = map[string]string(podNodeSelectorLabels)
	return nil
}
Exemple #7
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
}