Function downloadAsset

pkg/cmd/release/download/download.go:273–324

(dest *destinationWriter, httpClient *http.Client, assetURL, fileName string, isArchive bool)

}

func downloadAsset(dest *destinationWriter, httpClient *http.Client, assetURL, fileName string, isArchive bool) error {
	if err := dest.Check(fileName); err != nil {
		return err
	}

	req, err := http.NewRequest("GET", assetURL, nil)
	if err != nil {
		return err
	}

	req.Header.Set("Accept", "application/octet-stream")
	if isArchive {
		// adding application/json to Accept header due to a bug in the zipball/tarball API endpoint that makes it mandatory
		req.Header.Set("Accept", "application/octet-stream, application/json")

		// override HTTP redirect logic to avoid "legacy" Codeload resources
		oldClient := *httpClient
		httpClient = &oldClient
		httpClient.CheckRedirect = func(req *http.Request, via []*http.Request) error {
			if len(via) == 1 {
				req.URL.Path = removeLegacyFromCodeloadPath(req.URL.Path)
			}
			return nil
		}
	}

	resp, err := httpClient.Do(req)
	if err != nil {
		return err
	}
	defer resp.Body.Close()

	if resp.StatusCode > 299 {
		return api.HandleHTTPError(resp)
	}

	if len(fileName) == 0 {
		contentDisposition := resp.Header.Get("Content-Disposition")

		_, params, err := mime.ParseMediaType(contentDisposition)
		if err != nil {
			return fmt.Errorf("unable to parse file name of archive: %w", err)
		}
		if serverFileName, ok := params["filename"]; ok {
			fileName = filepath.Base(serverFileName)
		} else {
			return errors.New("unable to determine file name of archive")
		}
	}

	return dest.Copy(fileName, resp.Body)
}

var codeloadLegacyRE = regexp.MustCompile(`^(/[^/]+/[^/]+/)legacy\.`)