mirror of https://github.com/k3s-io/k3s
112 lines
2.7 KiB
Go
112 lines
2.7 KiB
Go
/*
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Copyright 2014 Google Inc. 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 dockertools
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import (
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"sync"
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"time"
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"github.com/GoogleCloudPlatform/kubernetes/pkg/kubelet/container"
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)
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type DockerCache interface {
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GetPods() ([]*container.Pod, error)
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ForceUpdateIfOlder(time.Time) error
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}
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func NewDockerCache(client DockerInterface) (DockerCache, error) {
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return &dockerCache{
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client: client,
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updatingCache: false,
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}, nil
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}
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// dockerCache is a default implementation of DockerCache interface
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type dockerCache struct {
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// The underlying docker client used to update the cache.
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client DockerInterface
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// Mutex protecting all of the following fields.
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lock sync.Mutex
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// Last time when cache was updated.
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cacheTime time.Time
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// The content of the cache.
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pods []*container.Pod
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// Whether the background thread updating the cache is running.
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updatingCache bool
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// Time when the background thread should be stopped.
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updatingThreadStopTime time.Time
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}
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// Ensure that dockerCache abides by the DockerCache interface.
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var _ DockerCache = new(dockerCache)
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func (d *dockerCache) GetPods() ([]*container.Pod, error) {
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d.lock.Lock()
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defer d.lock.Unlock()
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if time.Since(d.cacheTime) > 2*time.Second {
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pods, err := GetPods(d.client, false)
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if err != nil {
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return pods, err
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}
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d.pods = pods
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d.cacheTime = time.Now()
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}
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// Stop refreshing thread if there were no requests within last 2 seconds.
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d.updatingThreadStopTime = time.Now().Add(time.Duration(2) * time.Second)
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if !d.updatingCache {
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d.updatingCache = true
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go d.startUpdatingCache()
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}
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return d.pods, nil
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}
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func (d *dockerCache) ForceUpdateIfOlder(minExpectedCacheTime time.Time) error {
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d.lock.Lock()
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defer d.lock.Unlock()
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if d.cacheTime.Before(minExpectedCacheTime) {
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pods, err := GetPods(d.client, false)
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if err != nil {
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return err
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}
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d.pods = pods
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d.cacheTime = time.Now()
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}
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return nil
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}
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func (d *dockerCache) startUpdatingCache() {
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run := true
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for run {
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time.Sleep(100 * time.Millisecond)
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pods, err := GetPods(d.client, false)
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cacheTime := time.Now()
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if err != nil {
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continue
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}
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d.lock.Lock()
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if time.Now().After(d.updatingThreadStopTime) {
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d.updatingCache = false
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run = false
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}
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d.pods = pods
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d.cacheTime = cacheTime
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d.lock.Unlock()
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}
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}
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