| /* |
| 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 images |
| |
| import ( |
| "fmt" |
| |
| "k8s.io/api/core/v1" |
| "k8s.io/client-go/util/flowcontrol" |
| kubecontainer "k8s.io/kubernetes/pkg/kubelet/container" |
| ) |
| |
| // throttleImagePulling wraps kubecontainer.ImageService to throttle image |
| // pulling based on the given QPS and burst limits. If QPS is zero, defaults |
| // to no throttling. |
| func throttleImagePulling(imageService kubecontainer.ImageService, qps float32, burst int) kubecontainer.ImageService { |
| if qps == 0.0 { |
| return imageService |
| } |
| return &throttledImageService{ |
| ImageService: imageService, |
| limiter: flowcontrol.NewTokenBucketRateLimiter(qps, burst), |
| } |
| } |
| |
| type throttledImageService struct { |
| kubecontainer.ImageService |
| limiter flowcontrol.RateLimiter |
| } |
| |
| func (ts throttledImageService) PullImage(image kubecontainer.ImageSpec, secrets []v1.Secret) (string, error) { |
| if ts.limiter.TryAccept() { |
| return ts.ImageService.PullImage(image, secrets) |
| } |
| return "", fmt.Errorf("pull QPS exceeded") |
| } |