k3s/vendor/k8s.io/kubernetes/plugin/pkg/admission/antiaffinity/doc.go

30 lines
1.4 KiB
Go

/*
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.
*/
// Package antiaffinity provides the LimitPodHardAntiAffinityTopology
// admission controller. It rejects any pod that specifies "hard"
// (RequiredDuringScheduling) anti-affinity with a TopologyKey other
// than v1.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"