download_single_file.go

func downloadFile(URL string) ([]byte, error) {
	response, err := http.Get(URL)
	if err != nil {
		return nil, err
	}
        defer response.Body.Close()
	if response.StatusCode != http.StatusOK {
		return nil, errors.New(response.Status)
	}
	var data bytes.Buffer
	_, err = io.Copy(&data, response.Body)
	if err != nil {
		return nil, err
	}
	return data.Bytes(), nil
}