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