helm v3源码分析之总体

发布一个k8s部署视频：https://edu.csdn.net/course/detail/26967

课程内容：各种k8s部署方式。包括minikube部署，kubeadm部署，kubeasz部署，rancher部署，k3s部署。包括开发测试环境部署k8s，和生产环境部署k8s。

腾讯课堂连接地址https://ke.qq.com/course/478827?taid=4373109931462251&tuin=ba64518

第二个视频发布 https://edu.csdn.net/course/detail/27109

腾讯课堂连接地址https://ke.qq.com/course/484107?tuin=ba64518

介绍主要的k8s资源的使用配置和命令。包括configmap，pod，service，replicaset，namespace，deployment，daemonset，ingress，pv，pvc，sc，role，rolebinding，clusterrole，clusterrolebinding，secret，serviceaccount，statefulset，job，cronjob，podDisruptionbudget，podSecurityPolicy,networkPolicy,resourceQuota，limitrange，endpoint，event，conponentstatus，node，apiservice，controllerRevision等。

第三个视频发布：https://edu.csdn.net/course/detail/27574

详细介绍helm命令，学习helm chart语法，编写helm chart。深入分析各项目源码，学习编写helm插件

第四个课程发布：https://edu.csdn.net/course/detail/28488

本课程将详细介绍k8s所有命令，以及命令的go源码分析，学习知其然，知其所以然

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func main() {//程序入口
 initKubeLogs()//初始化kube日志

 actionConfig := new(action.Configuration)
 cmd := newRootCmd(actionConfig, os.Stdout, os.Args[1:])//创建根命令

 if err := actionConfig.Init(settings.RESTClientGetter(), settings.Namespace(), os.Getenv("HELM_DRIVER"), debug); err != nil {//初始化
  log.Fatal(err)
 }

 if err := cmd.Execute(); err != nil {执行命令
  debug("%+v", err)
  switch e := err.(type) {
  case pluginError:
   os.Exit(e.code)
  default:
   os.Exit(1)
  }
 }
}

func newRootCmd(actionConfig *action.Configuration, out io.Writer, args []string) *cobra.Command {//获取根命令
 cmd := &cobra.Command{//创建cobra命令
  Use:                    "helm",
  Short:                  "The Helm package manager for Kubernetes.",
  Long:                   globalUsage,
  SilenceUsage:           true,
  Args:                   require.NoArgs,
  BashCompletionFunction: fmt.Sprintf("%s%s", contextCompFunc, completion.GetBashCustomFunction()),
 }
 flags := cmd.PersistentFlags()

 settings.AddFlags(flags)//添加选项

 flag := flags.Lookup("namespace")
 // Setup shell completion for the namespace flag
 completion.RegisterFlagCompletionFunc(flag, func(cmd *cobra.Command, args []string, toComplete string) ([]string, completion.BashCompDirective) {//自动补全
  if client, err := actionConfig.KubernetesClientSet(); err == nil {
   // Choose a long enough timeout that the user notices somethings is not working
   // but short enough that the user is not made to wait very long
   to := int64(3)
   completion.CompDebugln(fmt.Sprintf("About to call kube client for namespaces with timeout of: %d", to))

   nsNames := []string{}
   if namespaces, err := client.CoreV1().Namespaces().List(metav1.ListOptions{TimeoutSeconds: &to}); err == nil {
    for _, ns := range namespaces.Items {
     if strings.HasPrefix(ns.Name, toComplete) {
      nsNames = append(nsNames, ns.Name)
     }
    }
    return nsNames, completion.BashCompDirectiveNoFileComp
   }
  }
  return nil, completion.BashCompDirectiveDefault
 })

 // We can safely ignore any errors that flags.Parse encounters since
 // those errors will be caught later during the call to cmd.Execution.
 // This call is required to gather configuration information prior to
 // execution.
 flags.ParseErrorsWhitelist.UnknownFlags = true
 flags.Parse(args)

 // Add subcommands
 cmd.AddCommand(//添加子命令
  // chart commands
  newCreateCmd(out),// 添加create命令
  newDependencyCmd(out),// 添加dependency命令
  newPullCmd(out),//添加pull命令
  newShowCmd(out),//添加show命令
  newLintCmd(out),//添加lint命令
  newPackageCmd(out),//添加package命令
  newRepoCmd(out),//添加repo命令
  newSearchCmd(out),//添加search命令
  newVerifyCmd(out),//添加verify命令

  // release commands
  newGetCmd(actionConfig, out),//添加get命令
  newHistoryCmd(actionConfig, out),//添加history命令
  newInstallCmd(actionConfig, out),//添加install命令
  newListCmd(actionConfig, out),//添加list命令
  newReleaseTestCmd(actionConfig, out),//添加test命令
  newRollbackCmd(actionConfig, out),//添加rollback命令
  newStatusCmd(actionConfig, out),//添加status命令
  newTemplateCmd(actionConfig, out),//添加template命令
  newUninstallCmd(actionConfig, out),//添加uninstall命令
  newUpgradeCmd(actionConfig, out),//添加upgrade命令

  newCompletionCmd(out),//添加completion命令
  newEnvCmd(out),//添加env命令
  newPluginCmd(out),//添加plugin命令
  newVersionCmd(out),// 添加version命令

  // Hidden documentation generator command: 'helm docs'
  newDocsCmd(out),//添加docs命令

  // Setup the special hidden __complete command to allow for dynamic auto-completion
  completion.NewCompleteCmd(settings, out),
 )

 // Add annotation to flags for which we can generate completion choices
 for name, completion := range bashCompletionFlags {
  if cmd.Flag(name) != nil {
   if cmd.Flag(name).Annotations == nil {
    cmd.Flag(name).Annotations = map[string][]string{}
   }
   cmd.Flag(name).Annotations[cobra.BashCompCustom] = append(
    cmd.Flag(name).Annotations[cobra.BashCompCustom],
    completion,
   )
  }
 }

 // Add *experimental* subcommands
 registryClient, err := registry.NewClient(
  registry.ClientOptDebug(settings.Debug),
  registry.ClientOptWriter(out),
 )
 if err != nil {
  // TODO: don't panic here, refactor newRootCmd to return error
  panic(err)
 }
 actionConfig.RegistryClient = registryClient
 cmd.AddCommand(
  newRegistryCmd(actionConfig, out),//添加registry命令
  newChartCmd(actionConfig, out),//添加chart命令
 )

 // Find and add plugins
 loadPlugins(cmd, out)//加载插件

 return cmd
}