Method DownloadWithChecksum

http/download.go:176–235

DownloadWithChecksum starts new download task with checksum verification

(ctx context.Context, url string, destination string,
	expected *utils.ChecksumInfo, ignoreMismatch bool)

// DownloadWithChecksum starts new download task with checksum verification
func (downloader *downloaderImpl) DownloadWithChecksum(ctx context.Context, url string, destination string,
	expected *utils.ChecksumInfo, ignoreMismatch bool) error {

	if downloader.progress != nil {
		downloader.progress.Printf("Downloading: %s\n", url)
		defer downloader.progress.Flush()
	}
	req, err := downloader.newRequest(ctx, "GET", url)

	var temppath string
	maxTries := downloader.maxTries
	const delayMax = time.Duration(5 * time.Minute)
	delay := time.Duration(1 * time.Second)
	const delayMultiplier = 2
	for maxTries > 0 {
		temppath, err = downloader.download(req, url, destination, expected, ignoreMismatch)

		if err != nil {
			if retryableError(err) {
				if downloader.progress != nil {
					downloader.progress.Printf("Error (retrying): %s\n", err)
				}
				maxTries--
				time.Sleep(delay)
				// Sleep exponentially at the next retry, but no longer than delayMax
				delay *= delayMultiplier
				if delay > delayMax {
					delay = delayMax
				}
			} else {
				if downloader.progress != nil {
					downloader.progress.Printf("Error: %s \n", err)
				}
				break
			}
		} else {
			// get out of the loop
			break
		}
		if downloader.progress != nil {
			downloader.progress.Printf("Retrying %d %s...\n", maxTries, url)
		}
	}

	// still an error after retrying, giving up
	if err != nil {
		if downloader.progress != nil {
			downloader.progress.Printf("Download Error: %s\n", url)
		}
		return err
	}

	err = os.Rename(temppath, destination)
	if err != nil {
		_ = os.Remove(temppath)
		return errors.Wrap(err, url)
	}