// 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
}
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
}