| /* |
| Copyright 2016 The Kubernetes Authors. |
| |
| Licensed under the Apache License, Version 2.0 (the "License"); |
| you may not use this file except in compliance with the License. |
| You may obtain a copy of the License at |
| |
| http://www.apache.org/licenses/LICENSE-2.0 |
| |
| Unless required by applicable law or agreed to in writing, software |
| distributed under the License is distributed on an "AS IS" BASIS, |
| WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| See the License for the specific language governing permissions and |
| limitations under the License. |
| */ |
| |
| // LimitPodHardAntiAffinityTopology admission controller rejects any pod |
| // that specifies "hard" (RequiredDuringScheduling) anti-affinity |
| // with a TopologyKey other than kubeletapis.LabelHostname. |
| // Because anti-affinity is symmetric, without this admission controller, |
| // a user could maliciously or accidentally specify that their pod (once it has scheduled) |
| // should block other pods from scheduling into the same zone or some other large topology, |
| // essentially DoSing the cluster. |
| // In the future we will address this problem more fully by using quota and priority, |
| // but for now this admission controller provides a simple protection, |
| // on the assumption that the only legitimate use of hard pod anti-affinity |
| // is to exclude other pods from the same node. |
| package antiaffinity // import "k8s.io/kubernetes/plugin/pkg/admission/antiaffinity" |
