Golang flock.Acquire函数代码示例

func run(s *options.KubeletServer, kcfg *KubeletConfig) (err error) {
	if s.ExitOnLockContention && s.LockFilePath == "" {
		return errors.New("cannot exit on lock file contention: no lock file specified")
	}

	done := make(chan struct{})
	if s.LockFilePath != "" {
		glog.Infof("acquiring lock on %q", s.LockFilePath)
		if err := flock.Acquire(s.LockFilePath); err != nil {
			return fmt.Errorf("unable to acquire file lock on %q: %v", s.LockFilePath, err)
		}
		if s.ExitOnLockContention {
			glog.Infof("watching for inotify events for: %v", s.LockFilePath)
			if err := watchForLockfileContention(s.LockFilePath, done); err != nil {
				return err
			}
		}
	}
	if c, err := configz.New("componentconfig"); err == nil {
		c.Set(s.KubeletConfiguration)
	} else {
		glog.Errorf("unable to register configz: %s", err)
	}
	if kcfg == nil {
		cfg, err := UnsecuredKubeletConfig(s)
		if err != nil {
			return err
		}
		kcfg = cfg

		clientConfig, err := CreateAPIServerClientConfig(s)
		if err == nil {
			kcfg.KubeClient, err = clientset.NewForConfig(clientConfig)

			// make a separate client for events
			eventClientConfig := *clientConfig
			eventClientConfig.QPS = float32(s.EventRecordQPS)
			eventClientConfig.Burst = int(s.EventBurst)
			kcfg.EventClient, err = clientset.NewForConfig(&eventClientConfig)
		}
		if err != nil && len(s.APIServerList) > 0 {
			glog.Warningf("No API client: %v", err)
		}

		if s.CloudProvider == kubeExternal.AutoDetectCloudProvider {
			kcfg.AutoDetectCloudProvider = true
		} else {
			cloud, err := cloudprovider.InitCloudProvider(s.CloudProvider, s.CloudConfigFile)
			if err != nil {
				return err
			}
			if cloud == nil {
				glog.V(2).Infof("No cloud provider specified: %q from the config file: %q\n", s.CloudProvider, s.CloudConfigFile)
			} else {
				glog.V(2).Infof("Successfully initialized cloud provider: %q from the config file: %q\n", s.CloudProvider, s.CloudConfigFile)
				kcfg.Cloud = cloud
			}
		}
	}

	if kcfg.CAdvisorInterface == nil {
		kcfg.CAdvisorInterface, err = cadvisor.New(uint(s.CAdvisorPort), kcfg.ContainerRuntime)
		if err != nil {
			return err
		}
	}

	if kcfg.ContainerManager == nil {
		if kcfg.SystemCgroups != "" && kcfg.CgroupRoot == "" {
			return fmt.Errorf("invalid configuration: system container was specified and cgroup root was not specified")
		}
		kcfg.ContainerManager, err = cm.NewContainerManager(kcfg.Mounter, kcfg.CAdvisorInterface, cm.NodeConfig{
			RuntimeCgroupsName: kcfg.RuntimeCgroups,
			SystemCgroupsName:  kcfg.SystemCgroups,
			KubeletCgroupsName: kcfg.KubeletCgroups,
			ContainerRuntime:   kcfg.ContainerRuntime,
			CgroupsPerQOS:      kcfg.CgroupsPerQOS,
			CgroupRoot:         kcfg.CgroupRoot,
		})
		if err != nil {
			return err
		}
	}

	runtime.ReallyCrash = s.ReallyCrashForTesting
	rand.Seed(time.Now().UTC().UnixNano())

	// TODO(vmarmol): Do this through container config.
	oomAdjuster := kcfg.OOMAdjuster
	if err := oomAdjuster.ApplyOOMScoreAdj(0, int(s.OOMScoreAdj)); err != nil {
		glog.Warning(err)
	}

	if err := RunKubelet(kcfg); err != nil {
		return err
	}

	if s.HealthzPort > 0 {
		healthz.DefaultHealthz()
		go wait.Until(func() {
//.........这里部分代码省略.........

func run(s *options.KubeletServer, kubeDeps *kubelet.KubeletDeps) (err error) {
	// TODO: this should be replaced by a --standalone flag
	standaloneMode := (len(s.APIServerList) == 0 && !s.RequireKubeConfig)

	if s.ExitOnLockContention && s.LockFilePath == "" {
		return errors.New("cannot exit on lock file contention: no lock file specified")
	}

	done := make(chan struct{})
	if s.LockFilePath != "" {
		glog.Infof("acquiring file lock on %q", s.LockFilePath)
		if err := flock.Acquire(s.LockFilePath); err != nil {
			return fmt.Errorf("unable to acquire file lock on %q: %v", s.LockFilePath, err)
		}
		if s.ExitOnLockContention {
			glog.Infof("watching for inotify events for: %v", s.LockFilePath)
			if err := watchForLockfileContention(s.LockFilePath, done); err != nil {
				return err
			}
		}
	}

	// Set feature gates based on the value in KubeletConfiguration
	err = utilconfig.DefaultFeatureGate.Set(s.KubeletConfiguration.FeatureGates)
	if err != nil {
		return err
	}

	// Register current configuration with /configz endpoint
	cfgz, cfgzErr := initConfigz(&s.KubeletConfiguration)
	if utilconfig.DefaultFeatureGate.DynamicKubeletConfig() {
		// Look for config on the API server. If it exists, replace s.KubeletConfiguration
		// with it and continue. initKubeletConfigSync also starts the background thread that checks for new config.

		// Don't do dynamic Kubelet configuration in runonce mode
		if s.RunOnce == false {
			remoteKC, err := initKubeletConfigSync(s)
			if err == nil {
				// Update s (KubeletServer) with new config from API server
				s.KubeletConfiguration = *remoteKC
				// Ensure that /configz is up to date with the new config
				if cfgzErr != nil {
					glog.Errorf("was unable to register configz before due to %s, will not be able to set now", cfgzErr)
				} else {
					setConfigz(cfgz, &s.KubeletConfiguration)
				}
				// Update feature gates from the new config
				err = utilconfig.DefaultFeatureGate.Set(s.KubeletConfiguration.FeatureGates)
				if err != nil {
					return err
				}
			}
		}
	}

	if kubeDeps == nil {
		var kubeClient, eventClient *clientset.Clientset
		var cloud cloudprovider.Interface

		if s.CloudProvider != componentconfigv1alpha1.AutoDetectCloudProvider {
			cloud, err = cloudprovider.InitCloudProvider(s.CloudProvider, s.CloudConfigFile)
			if err != nil {
				return err
			}
			if cloud == nil {
				glog.V(2).Infof("No cloud provider specified: %q from the config file: %q\n", s.CloudProvider, s.CloudConfigFile)
			} else {
				glog.V(2).Infof("Successfully initialized cloud provider: %q from the config file: %q\n", s.CloudProvider, s.CloudConfigFile)
			}
		}

		if s.BootstrapKubeconfig != "" {
			nodeName, err := getNodeName(cloud, nodeutil.GetHostname(s.HostnameOverride))
			if err != nil {
				return err
			}
			if err := bootstrapClientCert(s.KubeConfig.Value(), s.BootstrapKubeconfig, s.CertDirectory, nodeName); err != nil {
				return err
			}
		}

		clientConfig, err := CreateAPIServerClientConfig(s)
		if err == nil {
			kubeClient, err = clientset.NewForConfig(clientConfig)
			if err != nil {
				glog.Warningf("New kubeClient from clientConfig error: %v", err)
			}
			// make a separate client for events
			eventClientConfig := *clientConfig
			eventClientConfig.QPS = float32(s.EventRecordQPS)
			eventClientConfig.Burst = int(s.EventBurst)
			eventClient, err = clientset.NewForConfig(&eventClientConfig)
		} else {
			if s.RequireKubeConfig {
				return fmt.Errorf("invalid kubeconfig: %v", err)
			}
			if standaloneMode {
				glog.Warningf("No API client: %v", err)
			}
		}
//.........这里部分代码省略.........

func run(s *options.KubeletServer, kcfg *KubeletConfig) (err error) {
	if s.LockFilePath != "" {
		glog.Infof("aquiring lock on %q", s.LockFilePath)
		if err := flock.Acquire(s.LockFilePath); err != nil {
			return fmt.Errorf("unable to aquire file lock on %q: %v", s.LockFilePath, err)
		}
	}
	if c, err := configz.New("componentconfig"); err == nil {
		c.Set(s.KubeletConfiguration)
	} else {
		glog.Errorf("unable to register configz: %s", err)
	}
	if kcfg == nil {
		cfg, err := UnsecuredKubeletConfig(s)
		if err != nil {
			return err
		}
		kcfg = cfg

		clientConfig, err := CreateAPIServerClientConfig(s)
		if err == nil {
			kcfg.KubeClient, err = clientset.NewForConfig(clientConfig)

			// make a separate client for events
			eventClientConfig := *clientConfig
			eventClientConfig.QPS = s.EventRecordQPS
			eventClientConfig.Burst = s.EventBurst
			kcfg.EventClient, err = clientset.NewForConfig(&eventClientConfig)
		}
		if err != nil && len(s.APIServerList) > 0 {
			glog.Warningf("No API client: %v", err)
		}

		cloud, err := cloudprovider.InitCloudProvider(s.CloudProvider, s.CloudConfigFile)
		if err != nil {
			return err
		}
		glog.V(2).Infof("Successfully initialized cloud provider: %q from the config file: %q\n", s.CloudProvider, s.CloudConfigFile)
		kcfg.Cloud = cloud
	}

	if kcfg.CAdvisorInterface == nil {
		kcfg.CAdvisorInterface, err = cadvisor.New(s.CAdvisorPort)
		if err != nil {
			return err
		}
	}

	if kcfg.ContainerManager == nil {
		if kcfg.SystemCgroups != "" && kcfg.CgroupRoot == "" {
			return fmt.Errorf("invalid configuration: system container was specified and cgroup root was not specified")
		}

		kcfg.ContainerManager, err = cm.NewContainerManager(kcfg.Mounter, kcfg.CAdvisorInterface, cm.NodeConfig{
			RuntimeCgroupsName: kcfg.RuntimeCgroups,
			SystemCgroupsName:  kcfg.SystemCgroups,
			KubeletCgroupsName: kcfg.KubeletCgroups,
			ContainerRuntime:   kcfg.ContainerRuntime,
		})
		if err != nil {
			return err
		}
	}

	runtime.ReallyCrash = s.ReallyCrashForTesting
	rand.Seed(time.Now().UTC().UnixNano())

	credentialprovider.SetPreferredDockercfgPath(s.RootDirectory)

	glog.V(2).Infof("Using root directory: %v", s.RootDirectory)

	// TODO(vmarmol): Do this through container config.
	oomAdjuster := kcfg.OOMAdjuster
	if err := oomAdjuster.ApplyOOMScoreAdj(0, s.OOMScoreAdj); err != nil {
		glog.Warning(err)
	}

	if err := RunKubelet(kcfg); err != nil {
		return err
	}

	if s.HealthzPort > 0 {
		healthz.DefaultHealthz()
		go wait.Until(func() {
			err := http.ListenAndServe(net.JoinHostPort(s.HealthzBindAddress, strconv.Itoa(s.HealthzPort)), nil)
			if err != nil {
				glog.Errorf("Starting health server failed: %v", err)
			}
		}, 5*time.Second, wait.NeverStop)
	}

	if s.RunOnce {
		return nil
	}

	// run forever
	select {}
}