func()

in lib/containerruntime/dockerdaemon/cli.go [106:154]

• 43 lines of code
• 8 McCabe index (conditional complexity)

func (cli *dockerClient) PullImage(ctx context.Context, repo, tag string) error {
	query := url.Values{}
	fromImage := fmt.Sprintf("%s/%s", cli.registry, repo)
	query.Set("fromImage", fromImage)
	query.Set("tag", tag)
	headers := map[string][]string{"X-Registry-Auth": {""}}
	urlPath := "/images/create"

	// Construct request. It veries depending on client version.
	var apiPath string
	if cli.version != "" {
		v := strings.TrimPrefix(cli.version, "v")
		apiPath = fmt.Sprintf("%s/v%s%s", cli.basePath, v, urlPath)
	} else {
		apiPath = fmt.Sprintf("%s%s", cli.basePath, urlPath)
	}
	u := &url.URL{Path: apiPath}
	if len(query) > 0 {
		u.RawQuery = query.Encode()
	}
	req, err := http.NewRequest("POST", u.String(), bytes.NewReader([]byte{}))
	if err != nil {
		return fmt.Errorf("create request: %s", err)
	}
	req.Header = headers
	req.Host = "docker"
	req.URL.Host = cli.addr
	req.URL.Scheme = cli.scheme

	resp, err := ctxhttp.Do(ctx, cli.client, req)
	if err != nil {
		return fmt.Errorf("send post request: %s", err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != 200 {
		errMsg, err := ioutil.ReadAll(resp.Body)
		if err != nil {
			return fmt.Errorf("read error resp: %s", err)
		}
		return fmt.Errorf("Error posting to %s: code %d, err: %s", urlPath, resp.StatusCode, errMsg)
	}

	// Docker daemon returns 200 early. Close resp.Body after reading all.
	if _, err := ioutil.ReadAll(resp.Body); err != nil {
		return fmt.Errorf("read resp body: %s", err)
	}

	return nil
}