helm源码分析之create命令

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 目前刚开始写一个月，一共写了18篇原创文章，文章目录如下：

istio多集群探秘，部署了50次多集群后我得出的结论

istio多集群链路追踪，附实操视频

istio防故障利器，你知道几个,istio新手不要读，太难！

istio业务权限控制，原来可以这么玩

istio实现非侵入压缩，微服务之间如何实现压缩

不懂envoyfilter也敢说精通istio系列-http-rbac-不要只会用AuthorizationPolicy配置权限

不懂envoyfilter也敢说精通istio系列-02-http-corsFilter-不要只会vs

不懂envoyfilter也敢说精通istio系列-03-http-csrf filter-再也不用再代码里写csrf逻辑了

不懂envoyfilter也敢说精通istio系列http-jwt_authn-不要只会RequestAuthorization

不懂envoyfilter也敢说精通istio系列-05-fault-filter-故障注入不止是vs

不懂envoyfilter也敢说精通istio系列-06-http-match-配置路由不只是vs

不懂envoyfilter也敢说精通istio系列-07-负载均衡配置不止是dr

不懂envoyfilter也敢说精通istio系列-08-连接池和断路器

不懂envoyfilter也敢说精通istio系列-09-http-route filter

不懂envoyfilter也敢说精通istio系列-network filter-redis proxy

不懂envoyfilter也敢说精通istio系列-network filter-HttpConnectionManager

不懂envoyfilter也敢说精通istio系列-ratelimit-istio ratelimit完全手册

 

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type createOptions struct {//create结构体
	starter    string // --starter
	name       string
	starterDir string
}

func newCreateCmd(out io.Writer) *cobra.Command {//创建create命令
	o := &createOptions{}//初始化结构体

	cmd := &cobra.Command{//创建cobra命令
		Use:   "create NAME",
		Short: "create a new chart with the given name",
		Long:  createDesc,
		Args:  require.ExactArgs(1),
		RunE: func(cmd *cobra.Command, args []string) error {
			o.name = args[0]//设置name
			o.starterDir = helmpath.DataPath("starters")//设置starter目录
			return o.run(out)//运行
		},
	}

	cmd.Flags().StringVarP(&o.starter, "starter", "p", "", "The name or absolute path to Helm starter scaffold")//starter选项
	return cmd
}

func (o *createOptions) run(out io.Writer) error {//运行
	fmt.Fprintf(out, "Creating %s\n", o.name)//打印

	chartname := filepath.Base(o.name)//获取chart名称
	cfile := &chart.Metadata{//构造chart元数据
		Name:        chartname,
		Description: "A Helm chart for Kubernetes",
		Type:        "application",
		Version:     "0.1.0",
		AppVersion:  "0.1.0",
		APIVersion:  chart.APIVersionV2,
	}

	if o.starter != "" {//如果starter不为空
		// Create from the starter
		lstarter := filepath.Join(o.starterDir, o.starter)//获取starter路径
		// If path is absolute, we don't want to prefix it with helm starters folder
		if filepath.IsAbs(o.starter) {//如果是绝对路径，设置lstarter
			lstarter = o.starter
		}
		return chartutil.CreateFrom(cfile, filepath.Dir(o.name), lstarter)//从starter创建chart
	}

	_, err := chartutil.Create(chartname, filepath.Dir(o.name))//创建chart
	return err
}

//从starter创建chart
func CreateFrom(chartfile *chart.Metadata, dest, src string) error {
	schart, err := loader.Load(src)//加载starter chart
	if err != nil {
		return errors.Wrapf(err, "could not load %s", src)
	}

	schart.Metadata = chartfile//设置chart元数据

	var updatedTemplates []*chart.File

	for _, template := range schart.Templates {//遍历templates
		newData := transform(string(template.Data), schart.Name())//转换template chart名称
		updatedTemplates = append(updatedTemplates, &chart.File{Name: template.Name, Data: newData})
	}

	schart.Templates = updatedTemplates//设置templates
	b, err := yaml.Marshal(schart.Values)//把values转换成yaml
	if err != nil {
		return errors.Wrap(err, "reading values file")
	}

	var m map[string]interface{}
	if err := yaml.Unmarshal(transform(string(b), schart.Name()), &m); err != nil {//转换values里的chart名称，然后转成map
		return errors.Wrap(err, "transforming values file")
	}
	schart.Values = m//设置values

	// SaveDir looks for the file values.yaml when saving rather than the values
	// key in order to preserve the comments in the YAML. The name placeholder
	// needs to be replaced on that file.
	for _, f := range schart.Raw {//遍历chart文件
		if f.Name == ValuesfileName {
			f.Data = transform(string(f.Data), schart.Name())//转换文件中chart的名称
		}
	}

	return SaveDir(schart, dest)//保存chart
}

func Create(name, dir string) (string, error) {//创建chart
	path, err := filepath.Abs(dir)//获取chart绝对路径
	if err != nil {
		return path, err
	}

	if fi, err := os.Stat(path); err != nil {//判断路径是否存在
		return path, err
	} else if !fi.IsDir() {//判断路径是否是目录
		return path, errors.Errorf("no such directory %s", path)
	}

	cdir := filepath.Join(path, name)//获取chart目录
	if fi, err := os.Stat(cdir); err == nil && !fi.IsDir() {//判断chart目录是否存在并且是目录
		return cdir, errors.Errorf("file %s already exists and is not a directory", cdir)
	}

	files := []struct {//设置要生成的chart文件
		path    string
		content []byte
	}{
		{
			// Chart.yaml
			path:    filepath.Join(cdir, ChartfileName),
			content: []byte(fmt.Sprintf(defaultChartfile, name)),
		},
		{
			// values.yaml
			path:    filepath.Join(cdir, ValuesfileName),
			content: []byte(fmt.Sprintf(defaultValues, name)),
		},
		{
			// .helmignore
			path:    filepath.Join(cdir, IgnorefileName),
			content: []byte(defaultIgnore),
		},
		{
			// ingress.yaml
			path:    filepath.Join(cdir, IngressFileName),
			content: transform(defaultIngress, name),
		},
		{
			// deployment.yaml
			path:    filepath.Join(cdir, DeploymentName),
			content: transform(defaultDeployment, name),
		},
		{
			// service.yaml
			path:    filepath.Join(cdir, ServiceName),
			content: transform(defaultService, name),
		},
		{
			// serviceaccount.yaml
			path:    filepath.Join(cdir, ServiceAccountName),
			content: transform(defaultServiceAccount, name),
		},
		{
			// NOTES.txt
			path:    filepath.Join(cdir, NotesName),
			content: transform(defaultNotes, name),
		},
		{
			// _helpers.tpl
			path:    filepath.Join(cdir, HelpersName),
			content: transform(defaultHelpers, name),
		},
		{
			// test-connection.yaml
			path:    filepath.Join(cdir, TestConnectionName),
			content: transform(defaultTestConnection, name),
		},
	}

	for _, file := range files {//遍历文件
		if _, err := os.Stat(file.path); err == nil {//如果文件存在则跳过
			// File exists and is okay. Skip it.
			continue
		}
		if err := writeFile(file.path, file.content); err != nil {//写入文件到磁盘
			return cdir, err
		}
	}
	// Need to add the ChartsDir explicitly as it does not contain any file OOTB
	if err := os.MkdirAll(filepath.Join(cdir, ChartsDir), 0755); err != nil {//添加charts目录
		return cdir, err
	}
	return cdir, nil
}