kubectl源码分析之cluster-info dump_kubectl cluster-info dump-优快云博客

type ClusterInfoDumpOptions struct {//dump结构体
	PrintFlags *genericclioptions.PrintFlags
	PrintObj   printers.ResourcePrinterFunc

	OutputDir     string
	AllNamespaces bool
	Namespaces    []string

	Timeout          time.Duration
	AppsClient       appsv1client.AppsV1Interface
	CoreClient       corev1client.CoreV1Interface
	Namespace        string
	RESTClientGetter genericclioptions.RESTClientGetter
	LogsForObject    polymorphichelpers.LogsForObjectFunc

	genericclioptions.IOStreams
}

//创建dump命令
func NewCmdClusterInfoDump(f cmdutil.Factory, ioStreams genericclioptions.IOStreams) *cobra.Command {
	o := &ClusterInfoDumpOptions{//初始化dump结构体
		PrintFlags: genericclioptions.NewPrintFlags("").WithTypeSetter(scheme.Scheme).WithDefaultOutput("json"),

		IOStreams: ioStreams,
	}

	cmd := &cobra.Command{//创建cobra命令
		Use:     "dump",
		Short:   i18n.T("Dump lots of relevant info for debugging and diagnosis"),
		Long:    dumpLong,
		Example: dumpExample,
		Run: func(cmd *cobra.Command, args []string) {
			cmdutil.CheckErr(o.Complete(f, cmd))//准备
			cmdutil.CheckErr(o.Run())//运行
		},
	}

	o.PrintFlags.AddFlags(cmd)//打印选项

	cmd.Flags().StringVar(&o.OutputDir, "output-directory", o.OutputDir, i18n.T("Where to output the files.  If empty or '-' uses stdout, otherwise creates a directory hierarchy in that directory"))//output-directory选项
	cmd.Flags().StringSliceVar(&o.Namespaces, "namespaces", o.Namespaces, "A comma separated list of namespaces to dump.")//namespaces选项
	cmd.Flags().BoolVarP(&o.AllNamespaces, "all-namespaces", "A", o.AllNamespaces, "If true, dump all namespaces.  If true, --namespaces is ignored.")//all-namespace选项
	cmdutil.AddPodRunningTimeoutFlag(cmd, defaultPodLogsTimeout)//超时选项
	return cmd
}

//准备方法
func (o *ClusterInfoDumpOptions) Complete(f cmdutil.Factory, cmd *cobra.Command) error {
	printer, err := o.PrintFlags.ToPrinter()// print flag 转printer
	if err != nil {
		return err
	}

	o.PrintObj = printer.PrintObj//设置printObj函数

	config, err := f.ToRESTConfig()//获取restConfig
	if err != nil {
		return err
	}

	o.CoreClient, err = corev1client.NewForConfig(config)//设置coreClient
	if err != nil {
		return err
	}

	o.AppsClient, err = appsv1client.NewForConfig(config)//设置appsClient
	if err != nil {
		return err
	}

	o.Timeout, err = cmdutil.GetPodRunningTimeoutFlag(cmd)//设置超时
	if err != nil {
		return err
	}

	o.Namespace, _, err = f.ToRawKubeConfigLoader().Namespace()//设置namespace
	if err != nil {
		return err
	}
	// TODO this should eventually just be the completed kubeconfigflag struct
	o.RESTClientGetter = f//设置restclientgetter
	o.LogsForObject = polymorphichelpers.LogsForObjectFn//设置LogsForObject函数

	return nil
}

//运行
func (o *ClusterInfoDumpOptions) Run() error {
	nodes, err := o.CoreClient.Nodes().List(metav1.ListOptions{})//获取所有节点
	if err != nil {
		return err
	}

	if err := o.PrintObj(nodes, setupOutputWriter(o.OutputDir, o.Out, "nodes.json")); err != nil {//打印节点
		return err
	}

	var namespaces []string
	if o.AllNamespaces {//如果指定了all-namespaces
		namespaceList, err := o.CoreClient.Namespaces().List(metav1.ListOptions{})//获取所有namespace
		if err != nil {
			return err
		}
		for ix := range namespaceList.Items {//append namespaces
			namespaces = append(namespaces, namespaceList.Items[ix].Name)
		}
	} else {
		if len(o.Namespaces) == 0 {//如果namespaces为空
			namespaces = []string{//则用系统namespace和当前namespace
				metav1.NamespaceSystem,
				o.Namespace,
			}
		}
	}
	for _, namespace := range namespaces {//遍历namespaces
		// TODO: this is repetitive in the extreme.  Use reflection or
		// something to make this a for loop.
		events, err := o.CoreClient.Events(namespace).List(metav1.ListOptions{})//获取所有事件
		if err != nil {
			return err
		}
		if err := o.PrintObj(events, setupOutputWriter(o.OutputDir, o.Out, path.Join(namespace, "events.json"))); err != nil {//打印事件
			return err
		}

		rcs, err := o.CoreClient.ReplicationControllers(namespace).List(metav1.ListOptions{})//获取rc
		if err != nil {
			return err
		}
		if err := o.PrintObj(rcs, setupOutputWriter(o.OutputDir, o.Out, path.Join(namespace, "replication-controllers.json"))); err != nil {//打印rc
			return err
		}

		svcs, err := o.CoreClient.Services(namespace).List(metav1.ListOptions{})//获取service
		if err != nil {
			return err
		}
		if err := o.PrintObj(svcs, setupOutputWriter(o.OutputDir, o.Out, path.Join(namespace, "services.json"))); err != nil {//打印service
			return err
		}

		sets, err := o.AppsClient.DaemonSets(namespace).List(metav1.ListOptions{})//获取daemonset
		if err != nil {
			return err
		}
		if err := o.PrintObj(sets, setupOutputWriter(o.OutputDir, o.Out, path.Join(namespace, "daemonsets.json"))); err != nil {//打印daemonset
			return err
		}

		deps, err := o.AppsClient.Deployments(namespace).List(metav1.ListOptions{})//获取deployment
		if err != nil {
			return err
		}
		if err := o.PrintObj(deps, setupOutputWriter(o.OutputDir, o.Out, path.Join(namespace, "deployments.json"))); err != nil {//打印deployment
			return err
		}

		rps, err := o.AppsClient.ReplicaSets(namespace).List(metav1.ListOptions{})//获取rs
		if err != nil {
			return err
		}
		if err := o.PrintObj(rps, setupOutputWriter(o.OutputDir, o.Out, path.Join(namespace, "replicasets.json"))); err != nil {//打印rs
			return err
		}

		pods, err := o.CoreClient.Pods(namespace).List(metav1.ListOptions{})//获取pod
		if err != nil {
			return err
		}

		if err := o.PrintObj(pods, setupOutputWriter(o.OutputDir, o.Out, path.Join(namespace, "pods.json"))); err != nil {//打印pod
			return err
		}

		printContainer := func(writer io.Writer, container corev1.Container, pod *corev1.Pod) {//打印容器日志
			writer.Write([]byte(fmt.Sprintf("==== START logs for container %s of pod %s/%s ====\n", container.Name, pod.Namespace, pod.Name)))
			defer writer.Write([]byte(fmt.Sprintf("==== END logs for container %s of pod %s/%s ====\n", container.Name, pod.Namespace, pod.Name)))

			requests, err := o.LogsForObject(o.RESTClientGetter, pod, &corev1.PodLogOptions{Container: container.Name}, timeout, false)//获取日志请求
			if err != nil {
				// Print error and return.
				writer.Write([]byte(fmt.Sprintf("Create log request error: %s\n", err.Error())))
				return
			}

			for _, request := range requests {//遍历日志请求
				data, err := request.DoRaw()
				if err != nil {
					// Print error and return.
					writer.Write([]byte(fmt.Sprintf("Request log error: %s\n", err.Error())))
					return
				}
				writer.Write(data)//打印日
			}
		}

		for ix := range pods.Items {//遍历所有pod
			pod := &pods.Items[ix]
			containers := pod.Spec.Containers
			writer := setupOutputWriter(o.OutputDir, o.Out, path.Join(namespace, pod.Name, "logs.txt"))

			for i := range containers {//打印容器日志
				printContainer(writer, containers[i], pod)
			}
		}
	}

	dest := o.OutputDir
	if len(dest) == 0 {
		dest = "standard output"
	}
	if dest != "-" {//打印结束
		fmt.Fprintf(o.Out, "Cluster info dumped to %s\n", dest)
	}
	return nil
}