135 lines
4.3 KiB
Go
135 lines
4.3 KiB
Go
/*
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Copyright 2015 The Kubernetes Authors All rights reserved.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package autoscalercontroller
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import (
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"fmt"
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"time"
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"github.com/golang/glog"
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"k8s.io/kubernetes/pkg/api"
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client "k8s.io/kubernetes/pkg/client/unversioned"
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"k8s.io/kubernetes/pkg/controller/autoscaler/metrics"
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"k8s.io/kubernetes/pkg/expapi"
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"k8s.io/kubernetes/pkg/fields"
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"k8s.io/kubernetes/pkg/labels"
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"k8s.io/kubernetes/pkg/util"
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)
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type HorizontalPodAutoscalerController struct {
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client client.Interface
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expClient client.ExperimentalInterface
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metricsClient metrics.MetricsClient
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}
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var downscaleForbiddenWindow, _ = time.ParseDuration("20m")
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var upscaleForbiddenWindow, _ = time.ParseDuration("3m")
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func New(client client.Interface, expClient client.ExperimentalInterface, metricsClient metrics.MetricsClient) *HorizontalPodAutoscalerController {
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return &HorizontalPodAutoscalerController{
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client: client,
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expClient: expClient,
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metricsClient: metricsClient,
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}
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}
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func (a *HorizontalPodAutoscalerController) Run(syncPeriod time.Duration) {
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go util.Until(func() {
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if err := a.reconcileAutoscalers(); err != nil {
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glog.Errorf("Couldn't reconcile horizontal pod autoscalers: %v", err)
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}
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}, syncPeriod, util.NeverStop)
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}
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func (a *HorizontalPodAutoscalerController) reconcileAutoscalers() error {
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ns := api.NamespaceAll
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list, err := a.expClient.HorizontalPodAutoscalers(ns).List(labels.Everything(), fields.Everything())
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if err != nil {
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return fmt.Errorf("error listing nodes: %v", err)
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}
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for _, hpa := range list.Items {
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reference := fmt.Sprintf("%s/%s/%s", hpa.Spec.ScaleRef.Kind, hpa.Spec.ScaleRef.Namespace, hpa.Spec.ScaleRef.Name)
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scale, err := a.expClient.Scales(hpa.Spec.ScaleRef.Namespace).Get(hpa.Spec.ScaleRef.Kind, hpa.Spec.ScaleRef.Name)
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if err != nil {
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glog.Warningf("Failed to query scale subresource for %s: %v", reference, err)
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continue
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}
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currentReplicas := scale.Status.Replicas
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currentConsumption, err := a.metricsClient.ResourceConsumption(hpa.Spec.ScaleRef.Namespace).Get(hpa.Spec.Target.Resource,
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scale.Status.Selector)
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// TODO: what to do on partial errors (like metrics obtained for 75% of pods).
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if err != nil {
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glog.Warningf("Error while getting metrics for %s: %v", reference, err)
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continue
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}
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// if the ratio is 1.2 we want to have 2 replicas
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desiredReplicas := 1 + int((currentConsumption.Quantity.MilliValue()*int64(currentReplicas))/hpa.Spec.Target.Quantity.MilliValue())
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if desiredReplicas < hpa.Spec.MinCount {
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desiredReplicas = hpa.Spec.MinCount
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}
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if desiredReplicas > hpa.Spec.MaxCount {
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desiredReplicas = hpa.Spec.MaxCount
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}
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now := time.Now()
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rescale := false
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if desiredReplicas != currentReplicas {
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// Going down
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if desiredReplicas < currentReplicas && (hpa.Status == nil || hpa.Status.LastScaleTimestamp == nil ||
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hpa.Status.LastScaleTimestamp.Add(downscaleForbiddenWindow).Before(now)) {
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rescale = true
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}
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// Going up
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if desiredReplicas > currentReplicas && (hpa.Status == nil || hpa.Status.LastScaleTimestamp == nil ||
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hpa.Status.LastScaleTimestamp.Add(upscaleForbiddenWindow).Before(now)) {
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rescale = true
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}
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if rescale {
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scale.Spec.Replicas = desiredReplicas
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_, err = a.expClient.Scales(hpa.Namespace).Update(hpa.Spec.ScaleRef.Kind, scale)
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if err != nil {
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glog.Warningf("Failed to rescale %s: %v", reference, err)
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continue
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}
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}
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}
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status := expapi.HorizontalPodAutoscalerStatus{
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CurrentReplicas: currentReplicas,
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DesiredReplicas: desiredReplicas,
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CurrentConsumption: currentConsumption,
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}
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hpa.Status = &status
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if rescale {
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now := util.NewTime(now)
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hpa.Status.LastScaleTimestamp = &now
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}
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_, err = a.expClient.HorizontalPodAutoscalers(hpa.Namespace).Update(&hpa)
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if err != nil {
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glog.Warningf("Failed to update HorizontalPodAutoscaler %s: %v", hpa.Name, err)
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continue
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}
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}
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return nil
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}
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