helm源码分析之pull

ゝ一世哀愁。 2023-03-04 07:00 274阅读 0赞

#  欢迎关注我的公众号： #

![watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBAaHhwamF2YTE_size_8_color_FFFFFF_t_70_g_se_x_16][]

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_50]

[istio多集群链路追踪，附实操视频][istio]

[istio防故障利器，你知道几个,istio新手不要读，太难！][istio_istio]

[istio业务权限控制，原来可以这么玩][istio 1]

[istio实现非侵入压缩，微服务之间如何实现压缩][istio 2]

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

[不懂envoyfilter也敢说精通istio系列-02-http-corsFilter-不要只会vs][envoyfilter_istio_-02-http-corsFilter-_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][envoyfilter_istio_-03-http-csrf filter-_csrf]

[不懂envoyfilter也敢说精通istio系列http-jwt\_authn-不要只会RequestAuthorization][envoyfilter_istio_http-jwt_authn-_RequestAuthorization]

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

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

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

[不懂envoyfilter也敢说精通istio系列-08-连接池和断路器][envoyfilter_istio_-08-]

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

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

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

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

\------------------------------------------------------------------------------------------------------------

func newPullCmd(out io.Writer) *cobra.Command {//创建pull命令
    	client := action.NewPull()//初始化结构体
    
    	cmd := &cobra.Command{//创建cobra命令
    		Use:     "pull [chart URL | repo/chartname] [...]",
    		Short:   "download a chart from a repository and (optionally) unpack it in local directory",
    		Aliases: []string{"fetch"},
    		Long:    pullDesc,
    		Args:    require.MinimumNArgs(1),
    		RunE: func(cmd *cobra.Command, args []string) error {
    			client.Settings = settings//设置settings
    			if client.Version == "" && client.Devel {//如果没有指定version，则用开发版
    				debug("setting version to >0.0.0-0")
    				client.Version = ">0.0.0-0"
    			}
    
    			for i := 0; i < len(args); i++ {//遍历参数
    				output, err := client.Run(args[i])//运行拉取
    				if err != nil {
    					return err
    				}
    				fmt.Fprint(out, output)//打印结果
    			}
    			return nil
    		},
    	}
    
    	// Function providing dynamic auto-completion
    	completion.RegisterValidArgsFunc(cmd, func(cmd *cobra.Command, args []string, toComplete string) ([]string, completion.BashCompDirective) {
    		if len(args) != 0 {
    			return nil, completion.BashCompDirectiveNoFileComp
    		}
    		return compListCharts(toComplete, false)
    	})
    
    	f := cmd.Flags()
    	f.BoolVar(&client.Devel, "devel", false, "use development versions, too. Equivalent to version '>0.0.0-0'. If --version is set, this is ignored.")//devel选项
    	f.BoolVar(&client.Untar, "untar", false, "if set to true, will untar the chart after downloading it")//untar选项
    	f.BoolVar(&client.VerifyLater, "prov", false, "fetch the provenance file, but don't perform verification")//prov选项
    	f.StringVar(&client.UntarDir, "untardir", ".", "if untar is specified, this flag specifies the name of the directory into which the chart is expanded")//untardir选项
    	f.StringVarP(&client.DestDir, "destination", "d", ".", "location to write the chart. If this and tardir are specified, tardir is appended to this")//destinatio选项
    	addChartPathOptionsFlags(f, &client.ChartPathOptions)//chartpath选项
    
    	return cmd
    }

type Pull struct {//pull结构体
    	ChartPathOptions
    
    	Settings *cli.EnvSettings // TODO: refactor this out of pkg/action
    
    	Devel       bool
    	Untar       bool
    	VerifyLater bool
    	UntarDir    string
    	DestDir     string
    }
    
    // NewPull creates a new Pull object with the given configuration.
    func NewPull() *Pull {//创建pull结构体
    	return &Pull{}
    }

func (p *Pull) Run(chartRef string) (string, error) {
    	var out strings.Builder
    
    	c := downloader.ChartDownloader{//构造downloader
    		Out:     &out,
    		Keyring: p.Keyring,
    		Verify:  downloader.VerifyNever,
    		Getters: getter.All(p.Settings),
    		Options: []getter.Option{
    			getter.WithBasicAuth(p.Username, p.Password),
    			getter.WithTLSClientConfig(p.CertFile, p.KeyFile, p.CaFile),
    		},
    		RepositoryConfig: p.Settings.RepositoryConfig,
    		RepositoryCache:  p.Settings.RepositoryCache,
    	}
    
    	if p.Verify {//设置verify
    		c.Verify = downloader.VerifyAlways
    	} else if p.VerifyLater {
    		c.Verify = downloader.VerifyLater
    	}
    
    	// If untar is set, we fetch to a tempdir, then untar and copy after
    	// verification.
    	dest := p.DestDir//获取目标目录
    	if p.Untar {//如果指定了untar
    		var err error
    		dest, err = ioutil.TempDir("", "helm-")//目标目录为临时目录
    		if err != nil {
    			return out.String(), errors.Wrap(err, "failed to untar")
    		}
    		defer os.RemoveAll(dest)
    	}
    
    	if p.RepoURL != "" {//如果repoUrl不为空
    		chartURL, err := repo.FindChartInAuthRepoURL(p.RepoURL, p.Username, p.Password, chartRef, p.Version, p.CertFile, p.KeyFile, p.CaFile, getter.All(p.Settings))//获取charturl
    		if err != nil {
    			return out.String(), err
    		}
    		chartRef = chartURL
    	}
    
    	saved, v, err := c.DownloadTo(chartRef, p.Version, dest)//执行下载
    	if err != nil {
    		return out.String(), err
    	}
    
    	if p.Verify {//如果指定了verify，打印verify
    		fmt.Fprintf(&out, "Verification: %v\n", v)
    	}
    
    	// After verification, untar the chart into the requested directory.
    	if p.Untar {//如果指定了untar
    		ud := p.UntarDir//获取untardir
    		if !filepath.IsAbs(ud) {//如果untardir不是绝对路径
    			ud = filepath.Join(p.DestDir, ud)//凭借untardir
    		}
    		// Let udCheck to check conflict file/dir without replacing ud when untarDir is the current directory(.).
    		udCheck := ud
    		if udCheck == "." {//如果untardir为当前目录
    			_, udCheck = filepath.Split(chartRef)
    		} else {
    			_, chartName := filepath.Split(chartRef)
    			udCheck = filepath.Join(udCheck, chartName)
    		}
    		if _, err := os.Stat(udCheck); err != nil {//判断目录是否存在
    			if err := os.MkdirAll(udCheck, 0755); err != nil {//新创建目录
    				return out.String(), errors.Wrap(err, "failed to untar (mkdir)")
    			}
    
    		} else {
    			return out.String(), errors.Errorf("failed to untar: a file or directory with the name %s already exists", udCheck)
    		}
    
    		return out.String(), chartutil.ExpandFile(ud, saved)//展开文件
    	}
    	return out.String(), nil
    }

[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBAaHhwamF2YTE_size_8_color_FFFFFF_t_70_g_se_x_16]: /images/20230208/d249a6bc490a42e8861db718ad833ae2.png
[istio_50]: https://mp.weixin.qq.com/s/_OPMjmWCDSTlmbAxytg33A
[istio]: https://mp.weixin.qq.com/s/kjvtno_UzJAGr1joxm3tvw
[istio_istio]: https://mp.weixin.qq.com/s/e2-p_NY31Mc5y07S4Bb1JQ
[istio 1]: https://mp.weixin.qq.com/s/iTV0SCQLhSOTYncp3PxoHQ
[istio 2]: https://mp.weixin.qq.com/s/eINlrT242RlAwfuZu1_PcA
[envoyfilter_istio_-http-rbac-_AuthorizationPolicy]: https://mp.weixin.qq.com/s/Q-yTGBNqkjOov49LTXPrPA
[envoyfilter_istio_-02-http-corsFilter-_vs]: https://mp.weixin.qq.com/s/bFMdrT7OKSqoWv8pDXOIqQ
[envoyfilter_istio_-03-http-csrf filter-_csrf]: https://mp.weixin.qq.com/s/dlG9phV-kMMxs4UPzuRNYg
[envoyfilter_istio_http-jwt_authn-_RequestAuthorization]: https://mp.weixin.qq.com/s/IfrJ-FdLYsdhPkDrcO_YXA
[envoyfilter_istio_-05-fault-filter-_vs]: https://mp.weixin.qq.com/s/a4gDXqD8uswgglMwkUph2Q
[envoyfilter_istio_-06-http-match-_vs]: https://mp.weixin.qq.com/s/TpS3DHdcaJiPivIS_jsIGw
[envoyfilter_istio_-07-_dr]: https://mp.weixin.qq.com/s/k-zJm7n7OOKg6MotQJYPAA
[envoyfilter_istio_-08-]: https://mp.weixin.qq.com/s/n_bJ3saNeTtXRprIymhwzg
[envoyfilter_istio_-09-http-route filter]: https://mp.weixin.qq.com/s/JAeZr0BMVQxIrB3S_7Ru0A
[envoyfilter_istio_-network filter-redis proxy]: https://mp.weixin.qq.com/s/B9IPTI8F3q42nVkqbQRlPw
[envoyfilter_istio_-network filter-HttpConnectionManager]: https://mp.weixin.qq.com/s/W3OPQWkCVvuHGS49cTNhlg
[envoyfilter_istio_-ratelimit-istio ratelimit]: https://mp.weixin.qq.com/s/KgiDsELNol27mgZvDbFsqw