kubectl源码分析之set serviceaccount

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type SetServiceAccountOptions struct {//set serviceaccount结构体
  PrintFlags  *genericclioptions.PrintFlags
  RecordFlags *genericclioptions.RecordFlags

  fileNameOptions        resource.FilenameOptions
  dryRun                 bool
  shortOutput            bool
  all                    bool
  output                 string
  local                  bool
  updatePodSpecForObject polymorphichelpers.UpdatePodSpecForObjectFunc
  infos                  []*resource.Info
  serviceAccountName     string

  PrintObj printers.ResourcePrinterFunc
  Recorder genericclioptions.Recorder

  genericclioptions.IOStreams
}

func NewSetServiceAccountOptions(streams genericclioptions.IOStreams) *SetServiceAccountOptions {
  return &SetServiceAccountOptions{//初始化结构体
    PrintFlags:  genericclioptions.NewPrintFlags("serviceaccount updated").WithTypeSetter(scheme.Scheme),
    RecordFlags: genericclioptions.NewRecordFlags(),

    Recorder: genericclioptions.NoopRecorder{},

    IOStreams: streams,
  }
}

//创建set serviceaccount命令
func NewCmdServiceAccount(f cmdutil.Factory, streams genericclioptions.IOStreams) *cobra.Command {
  o := NewSetServiceAccountOptions(streams)//初始化结构体

  cmd := &cobra.Command{//创建cobra命令
    Use:                   "serviceaccount (-f FILENAME | TYPE NAME) SERVICE_ACCOUNT",
    DisableFlagsInUseLine: true,
    Aliases:               []string{"sa"},
    Short:                 i18n.T("Update ServiceAccount of a resource"),
    Long:                  serviceaccountLong,
    Example:               serviceaccountExample,
    Run: func(cmd *cobra.Command, args []string) {
      cmdutil.CheckErr(o.Complete(f, cmd, args))//准备
      cmdutil.CheckErr(o.Run())//运行
    },
  }

  o.PrintFlags.AddFlags(cmd)//设置print选项
  o.RecordFlags.AddFlags(cmd)//设置record选项

  usage := "identifying the resource to get from a server."
  cmdutil.AddFilenameOptionFlags(cmd, &o.fileNameOptions, usage)//设置文件选项
  cmd.Flags().BoolVar(&o.all, "all", o.all, "Select all resources, including uninitialized ones, in the namespace of the specified resource types")//设置all选项
  cmd.Flags().BoolVar(&o.local, "local", o.local, "If true, set serviceaccount will NOT contact api-server but run locally.")//设置local选项
  cmdutil.AddDryRunFlag(cmd)//设置干跑选项
  cmdutil.AddIncludeUninitializedFlag(cmd)
  return cmd
}

//准备
func (o *SetServiceAccountOptions) Complete(f cmdutil.Factory, cmd *cobra.Command, args []string) error {
  var err error

  o.RecordFlags.Complete(cmd)//record complete
  o.Recorder, err = o.RecordFlags.ToRecorder()//recordflag转recorder
  if err != nil {
    return err
  }

  o.shortOutput = cmdutil.GetFlagString(cmd, "output") == "name"//判断output是否为name
  o.dryRun = cmdutil.GetDryRunFlag(cmd)//设置干跑
  o.output = cmdutil.GetFlagString(cmd, "output")//设置output
  o.updatePodSpecForObject = polymorphichelpers.UpdatePodSpecForObjectFn//设置updatePodSpecforObject函数

  if o.dryRun {
    o.PrintFlags.Complete("%s (dry run)")
  }
  printer, err := o.PrintFlags.ToPrinter()//printflag转printer
  if err != nil {
    return err
  }
  o.PrintObj = printer.PrintObj//设置printObj函数

  cmdNamespace, enforceNamespace, err := f.ToRawKubeConfigLoader().Namespace()//获取namespace和enforceNamespace
  if err != nil {
    return err
  }
  if len(args) == 0 {//如果参数为空报错
    return errors.New("serviceaccount is required")
  }
  o.serviceAccountName = args[len(args)-1]
  resources := args[:len(args)-1]
  builder := f.NewBuilder().
    WithScheme(scheme.Scheme, scheme.Scheme.PrioritizedVersionsAllGroups()...).
    LocalParam(o.local).
    ContinueOnError().
    NamespaceParam(cmdNamespace).DefaultNamespace().
    FilenameParam(enforceNamespace, &o.fileNameOptions).
    Flatten()//构造info对象
  if !o.local {
    builder.ResourceTypeOrNameArgs(o.all, resources...).
      Latest()
  }
  o.infos, err = builder.Do().Infos()//设置info对象
  if err != nil {
    return err
  }
  return nil
}

func (o *SetServiceAccountOptions) Run() error {
  patchErrs := []error{}
  patchFn := func(obj runtime.Object) ([]byte, error) {//创建patch，修改海曙
    _, err := o.updatePodSpecForObject(obj, func(podSpec *v1.PodSpec) error {//更新pod spec
      podSpec.ServiceAccountName = o.serviceAccountName//更新serviceaccountName
      return nil
    })
    if err != nil {
      return nil, err
    }
    // record this change (for rollout history)
    if err := o.Recorder.Record(obj); err != nil {//判断是否创建change-cause注解
      klog.V(4).Infof("error recording current command: %v", err)
    }

    return runtime.Encode(scheme.DefaultJSONEncoder(), obj)//对象转json
  }

  patches := CalculatePatches(o.infos, scheme.DefaultJSONEncoder(), patchFn)//计算patch
  for _, patch := range patches {//遍历patch
    info := patch.Info
    name := info.ObjectName()
    if patch.Err != nil {//patch有错误则继续
      patchErrs = append(patchErrs, fmt.Errorf("error: %s %v\n", name, patch.Err))
      continue
    }
    if o.local || o.dryRun {//local或干跑则打印对象，继续
      if err := o.PrintObj(info.Object, o.Out); err != nil {
        patchErrs = append(patchErrs, err)
      }
      continue
    }
    actual, err := resource.NewHelper(info.Client, info.Mapping).Patch(info.Namespace, info.Name, types.StrategicMergePatchType, patch.Patch, nil)//应用patch到服务端
    if err != nil {
      patchErrs = append(patchErrs, fmt.Errorf("failed to patch ServiceAccountName %v", err))
      continue
    }

    if err := o.PrintObj(actual, o.Out); err != nil {//打印结果
      patchErrs = append(patchErrs, err)
    }
  }
  return utilerrors.NewAggregate(patchErrs)
}