Example #1
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) {

	// Ignore all calls to subresources
	if a.GetSubresource() != "" {
		return nil
	}

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

	key := &api.LimitRange{
		ObjectMeta: api.ObjectMeta{
			Namespace: a.GetNamespace(),
			Name:      "",
		},
	}
	items, err := l.indexer.Index("namespace", key)
	if err != nil {
		return admission.NewForbidden(a, fmt.Errorf("Unable to %s %s at this time because there was an error enforcing limit ranges", a.GetOperation(), resource))
	}
	if len(items) == 0 {
		return nil
	}

	// ensure it meets each prescribed min/max
	for i := range items {
		limitRange := items[i].(*api.LimitRange)
		err = l.limitFunc(limitRange, a.GetResource(), a.GetObject())
		if err != nil {
			return admission.NewForbidden(a, err)
		}
	}
	return nil
}
Example #2
0
func (q *quota) Admit(a admission.Attributes) (err error) {
	if a.GetSubresource() != "" {
		return nil
	}

	if a.GetOperation() == "DELETE" {
		return nil
	}

	key := &api.ResourceQuota{
		ObjectMeta: api.ObjectMeta{
			Namespace: a.GetNamespace(),
			Name:      "",
		},
	}

	// concurrent operations that modify quota tracked resources can cause a conflict when incrementing usage
	// as a result, we will attempt to increment quota usage per request up to numRetries limit
	// we fuzz each retry with an interval period to attempt to improve end-user experience during concurrent operations
	numRetries := 10
	interval := time.Duration(rand.Int63n(90)+int64(10)) * time.Millisecond

	items, err := q.indexer.Index("namespace", key)
	if err != nil {
		return admission.NewForbidden(a, fmt.Errorf("Unable to %s %s at this time because there was an error enforcing quota", a.GetOperation(), a.GetResource()))
	}
	if len(items) == 0 {
		return nil
	}

	for i := range items {

		quota := items[i].(*api.ResourceQuota)

		for retry := 1; retry <= numRetries; retry++ {

			// we cannot modify the value directly in the cache, so we copy
			status := &api.ResourceQuotaStatus{
				Hard: api.ResourceList{},
				Used: api.ResourceList{},
			}
			for k, v := range quota.Status.Hard {
				status.Hard[k] = *v.Copy()
			}
			for k, v := range quota.Status.Used {
				status.Used[k] = *v.Copy()
			}

			dirty, err := IncrementUsage(a, status, q.client)
			if err != nil {
				return admission.NewForbidden(a, err)
			}

			if dirty {
				// construct a usage record
				usage := api.ResourceQuota{
					ObjectMeta: api.ObjectMeta{
						Name:            quota.Name,
						Namespace:       quota.Namespace,
						ResourceVersion: quota.ResourceVersion,
						Labels:          quota.Labels,
						Annotations:     quota.Annotations},
				}
				usage.Status = *status
				_, err = q.client.ResourceQuotas(usage.Namespace).UpdateStatus(&usage)
				if err == nil {
					break
				}

				// we have concurrent requests to update quota, so look to retry if needed
				if retry == numRetries {
					return admission.NewForbidden(a, fmt.Errorf("Unable to %s %s at this time because there are too many concurrent requests to increment quota", a.GetOperation(), a.GetResource()))
				}
				time.Sleep(interval)
				// manually get the latest quota
				quota, err = q.client.ResourceQuotas(usage.Namespace).Get(quota.Name)
				if err != nil {
					return admission.NewForbidden(a, err)
				}
			}
		}
	}
	return nil
}