kubectl源码分析之create cronjob_kubectl cronjob command-优快云博客

type CreateCronJobOptions struct {//create cronjob结构体
	PrintFlags *genericclioptions.PrintFlags

	PrintObj func(obj runtime.Object) error

	Name     string
	Image    string
	Schedule string
	Command  []string
	Restart  string

	Namespace string
	Client    batchv1beta1client.BatchV1beta1Interface
	DryRun    bool
	Builder   *resource.Builder
	Cmd       *cobra.Command

	genericclioptions.IOStreams
}

func NewCreateCronJobOptions(ioStreams genericclioptions.IOStreams) *CreateCronJobOptions {
	return &CreateCronJobOptions{//初始化结构体
		PrintFlags: genericclioptions.NewPrintFlags("created").WithTypeSetter(scheme.Scheme),
		IOStreams:  ioStreams,
	}
}

//创建create cronjob 命令
func NewCmdCreateCronJob(f cmdutil.Factory, ioStreams genericclioptions.IOStreams) *cobra.Command {
	o := NewCreateCronJobOptions(ioStreams)//初始化结构体
	cmd := &cobra.Command{//创建cobra命令
		Use:     "cronjob NAME --image=image --schedule='0/5 * * * ?' -- [COMMAND] [args...]",
		Aliases: []string{"cj"},
		Short:   cronjobLong,
		Long:    cronjobLong,
		Example: cronjobExample,
		Run: func(cmd *cobra.Command, args []string) {
			cmdutil.CheckErr(o.Complete(f, cmd, args))//准备运行
			cmdutil.CheckErr(o.Validate())//校验
			cmdutil.CheckErr(o.Run())//运行
		},
	}

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

	cmdutil.AddApplyAnnotationFlags(cmd)//设置save-config选项
	cmdutil.AddValidateFlags(cmd)//设置validate选项
	cmdutil.AddDryRunFlag(cmd)//设置dry-run选项
	cmd.Flags().StringVar(&o.Image, "image", o.Image, "Image name to run.")//设置image选项
	cmd.Flags().StringVar(&o.Schedule, "schedule", o.Schedule, "A schedule in the Cron format the job should be run with.")//设置schedule选项
	cmd.Flags().StringVar(&o.Restart, "restart", o.Restart, "job's restart policy. supported values: OnFailure, Never")//设置restart选项

	return cmd
}

//准备方法
func (o *CreateCronJobOptions) Complete(f cmdutil.Factory, cmd *cobra.Command, args []string) error {
	name, err := NameFromCommandArgs(cmd, args)//获取名称
	if err != nil {
		return err
	}
	o.Name = name//设置名称
	if len(args) > 1 {
		o.Command = args[1:]//设置command
	}
	if len(o.Restart) == 0 {
		o.Restart = "OnFailure"//如果restart为空，则restart为OnFailure
	}

	clientConfig, err := f.ToRESTConfig()//获取restconfig
	if err != nil {
		return err
	}
	o.Client, err = batchv1beta1client.NewForConfig(clientConfig)//设置client
	if err != nil {
		return err
	}

	o.Namespace, _, err = f.ToRawKubeConfigLoader().Namespace()//设置namesapce
	if err != nil {
		return err
	}
	o.Builder = f.NewBuilder()//设置Builder
	o.Cmd = cmd

	o.DryRun = cmdutil.GetDryRunFlag(cmd)//设置dry-run
	if o.DryRun {
		o.PrintFlags.Complete("%s (dry run)")
	}
	printer, err := o.PrintFlags.ToPrinter()//print flag转printer
	if err != nil {
		return err
	}
	o.PrintObj = func(obj runtime.Object) error {//设置printObj函数
		return printer.PrintObj(obj, o.Out)
	}

	return nil
}

//校验
func (o *CreateCronJobOptions) Validate() error {
	if len(o.Image) == 0 {//image不能为空
		return fmt.Errorf("--image must be specified")
	}
	if len(o.Schedule) == 0 {//schedule不能为空
		return fmt.Errorf("--schedule must be specified")
	}
	return nil
}

//运行
func (o *CreateCronJobOptions) Run() error {
	var cronjob *batchv1beta1.CronJob
	cronjob = o.createCronJob()//创建Cronjob对象

	if !o.DryRun {
		var err error
		cronjob, err = o.Client.CronJobs(o.Namespace).Create(cronjob)//通过client创建cronjob
		if err != nil {
			return fmt.Errorf("failed to create cronjob: %v", err)
		}
	}

	return o.PrintObj(cronjob)//打印结果
}

func (o *CreateCronJobOptions) createCronJob() *batchv1beta1.CronJob {
	return &batchv1beta1.CronJob{//创建cronjob对象并赋值属性
		TypeMeta: metav1.TypeMeta{APIVersion: batchv1beta1.SchemeGroupVersion.String(), Kind: "CronJob"},
		ObjectMeta: metav1.ObjectMeta{
			Name: o.Name,
		},
		Spec: batchv1beta1.CronJobSpec{
			Schedule: o.Schedule,
			JobTemplate: batchv1beta1.JobTemplateSpec{
				ObjectMeta: metav1.ObjectMeta{
					Name: o.Name,
				},
				Spec: batchv1.JobSpec{
					Template: corev1.PodTemplateSpec{
						Spec: corev1.PodSpec{
							Containers: []corev1.Container{
								{
									Name:    o.Name,
									Image:   o.Image,
									Command: o.Command,
								},
							},
							RestartPolicy: corev1.RestartPolicy(o.Restart),
						},
					},
				},
			},
		},
	}
}