mirror of https://github.com/k3s-io/k3s
156 lines
3.9 KiB
Go
156 lines
3.9 KiB
Go
// +build linux
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/*
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Copyright 2016 The Kubernetes Authors.
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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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// Reads the pod configuration from file or a directory of files.
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package config
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import (
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"fmt"
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"os"
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"path/filepath"
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"strings"
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"time"
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"github.com/fsnotify/fsnotify"
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"k8s.io/klog"
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"k8s.io/api/core/v1"
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"k8s.io/apimachinery/pkg/util/wait"
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"k8s.io/client-go/util/flowcontrol"
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kubetypes "k8s.io/kubernetes/pkg/kubelet/types"
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)
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const (
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retryPeriod = 1 * time.Second
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maxRetryPeriod = 20 * time.Second
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)
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type retryableError struct {
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message string
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}
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func (e *retryableError) Error() string {
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return e.message
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}
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func (s *sourceFile) startWatch() {
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backOff := flowcontrol.NewBackOff(retryPeriod, maxRetryPeriod)
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backOffId := "watch"
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go wait.Forever(func() {
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if backOff.IsInBackOffSinceUpdate(backOffId, time.Now()) {
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return
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}
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if err := s.doWatch(); err != nil {
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klog.Errorf("Unable to read config path %q: %v", s.path, err)
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if _, retryable := err.(*retryableError); !retryable {
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backOff.Next(backOffId, time.Now())
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}
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}
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}, retryPeriod)
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}
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func (s *sourceFile) doWatch() error {
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_, err := os.Stat(s.path)
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if err != nil {
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if !os.IsNotExist(err) {
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return err
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}
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// Emit an update with an empty PodList to allow FileSource to be marked as seen
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s.updates <- kubetypes.PodUpdate{Pods: []*v1.Pod{}, Op: kubetypes.SET, Source: kubetypes.FileSource}
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return &retryableError{"path does not exist, ignoring"}
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}
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w, err := fsnotify.NewWatcher()
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if err != nil {
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return fmt.Errorf("unable to create inotify: %v", err)
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}
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defer w.Close()
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err = w.Add(s.path)
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if err != nil {
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return fmt.Errorf("unable to create inotify for path %q: %v", s.path, err)
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}
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for {
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select {
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case event := <-w.Events:
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if err = s.produceWatchEvent(&event); err != nil {
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return fmt.Errorf("error while processing inotify event (%+v): %v", event, err)
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}
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case err = <-w.Errors:
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return fmt.Errorf("error while watching %q: %v", s.path, err)
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}
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}
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}
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func (s *sourceFile) produceWatchEvent(e *fsnotify.Event) error {
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// Ignore file start with dots
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if strings.HasPrefix(filepath.Base(e.Name), ".") {
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klog.V(4).Infof("Ignored pod manifest: %s, because it starts with dots", e.Name)
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return nil
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}
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var eventType podEventType
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switch {
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case (e.Op & fsnotify.Create) > 0:
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eventType = podAdd
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case (e.Op & fsnotify.Write) > 0:
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eventType = podModify
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case (e.Op & fsnotify.Chmod) > 0:
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eventType = podModify
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case (e.Op & fsnotify.Remove) > 0:
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eventType = podDelete
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case (e.Op & fsnotify.Rename) > 0:
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eventType = podDelete
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default:
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// Ignore rest events
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return nil
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}
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s.watchEvents <- &watchEvent{e.Name, eventType}
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return nil
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}
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func (s *sourceFile) consumeWatchEvent(e *watchEvent) error {
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switch e.eventType {
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case podAdd, podModify:
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if pod, err := s.extractFromFile(e.fileName); err != nil {
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return fmt.Errorf("can't process config file %q: %v", e.fileName, err)
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} else {
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return s.store.Add(pod)
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}
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case podDelete:
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if objKey, keyExist := s.fileKeyMapping[e.fileName]; keyExist {
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pod, podExist, err := s.store.GetByKey(objKey)
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if err != nil {
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return err
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} else if !podExist {
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return fmt.Errorf("the pod with key %s doesn't exist in cache", objKey)
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} else {
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if err = s.store.Delete(pod); err != nil {
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return fmt.Errorf("failed to remove deleted pod from cache: %v", err)
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} else {
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delete(s.fileKeyMapping, e.fileName)
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}
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}
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}
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}
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return nil
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}
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