def get_container_file_download_url(cluster, environ, topology, container,<EOL>path, role=None):
params = dict(<EOL>cluster=cluster,<EOL>environ=environ,<EOL>topology=topology,<EOL>container=container,<EOL>path=path)<EOL>if role is not None:<EOL><INDENT>params['<STR_LIT>'] = role<EOL><DEDENT>request_url = tornado.httputil.url_concat(<EOL>create_url(FILE_DOWNLOAD_URL_FMT), params)<EOL>if role is not None:<EOL><INDENT>request_url = tornado.httputil.url_concat(request_url, dict(role=role))<EOL><DEDENT>return request_url<EOL>
:param cluster:
:param environ:
:param topology:
:param container:
:param path:
:param role:
:return: