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Files
descheduler/pkg/descheduler/strategies/pod_antiaffinity.go
2018-01-09 12:41:01 -05:00

102 lines
3.6 KiB
Go

/*
Copyright 2017 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 strategies
import (
"github.com/kubernetes-incubator/descheduler/cmd/descheduler/app/options"
"github.com/kubernetes-incubator/descheduler/pkg/api"
"github.com/kubernetes-incubator/descheduler/pkg/descheduler/evictions"
podutil "github.com/kubernetes-incubator/descheduler/pkg/descheduler/pod"
"github.com/golang/glog"
"k8s.io/api/core/v1"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
clientset "k8s.io/client-go/kubernetes"
priorityutil "k8s.io/kubernetes/plugin/pkg/scheduler/algorithm/priorities/util"
)
// RemovePodsViolatingInterPodAntiAffinity with elimination strategy
func RemovePodsViolatingInterPodAntiAffinity(ds *options.DeschedulerServer, strategy api.DeschedulerStrategy, policyGroupVersion string, nodes []*v1.Node) {
if !strategy.Enabled {
return
}
removePodsWithAffinityRules(ds.Client, policyGroupVersion, nodes, ds.DryRun)
}
// removePodsWithAffinityRules evicts pods on the node which are having a pod affinity rules.
func removePodsWithAffinityRules(client clientset.Interface, policyGroupVersion string, nodes []*v1.Node, dryRun bool) int {
podsEvicted := 0
for _, node := range nodes {
glog.V(1).Infof("Processing node: %#v\n", node.Name)
pods, err := podutil.ListEvictablePodsOnNode(client, node)
if err != nil {
return 0
}
totalPods := len(pods)
for i := 0; i < totalPods; i++ {
if checkPodsWithAntiAffinityExist(pods[i], pods) {
success, err := evictions.EvictPod(client, pods[i], policyGroupVersion, dryRun)
if !success {
glog.Infof("Error when evicting pod: %#v (%#v)\n", pods[i].Name, err)
} else {
podsEvicted++
glog.V(1).Infof("Evicted pod: %#v (%#v)\n because of existing anti-affinity", pods[i].Name, err)
// Since the current pod is evicted all other pods which have anti-affinity with this
// pod need not be evicted.
// Update pods.
pods = append(pods[:i], pods[i+1:]...)
i--
totalPods--
}
}
}
}
return podsEvicted
}
// checkPodsWithAntiAffinityExist checks if there are other pods on the node that the current pod cannot tolerate.
func checkPodsWithAntiAffinityExist(pod *v1.Pod, pods []*v1.Pod) bool {
affinity := pod.Spec.Affinity
if affinity != nil && affinity.PodAntiAffinity != nil {
for _, term := range getPodAntiAffinityTerms(affinity.PodAntiAffinity) {
namespaces := priorityutil.GetNamespacesFromPodAffinityTerm(pod, &term)
selector, err := metav1.LabelSelectorAsSelector(term.LabelSelector)
if err != nil {
glog.Infof("%v", err)
return false
}
for _, existingPod := range pods {
if existingPod.Name != pod.Name && priorityutil.PodMatchesTermsNamespaceAndSelector(existingPod, namespaces, selector) {
return true
}
}
}
}
return false
}
// getPodAntiAffinityTerms gets the antiaffinity terms for the given pod.
func getPodAntiAffinityTerms(podAntiAffinity *v1.PodAntiAffinity) (terms []v1.PodAffinityTerm) {
if podAntiAffinity != nil {
if len(podAntiAffinity.RequiredDuringSchedulingIgnoredDuringExecution) != 0 {
terms = podAntiAffinity.RequiredDuringSchedulingIgnoredDuringExecution
}
}
return terms
}