def gen_args()

in docker/serverless/env_start_proxy.py [0:0]
42 lines of code
11 McCabe index (conditional complexity)

def gen_args(cmd):

    ARGS = [
        cmd,
        "/apiproxy/start_proxy.py",
        "--on_serverless"
    ]

    # Uncaught AssertionError;
    # if no port, we can't serve a nice error handler. Crash instead.
    assert_env_var("PORT")
    ARGS.append("--http_port={}".format(os.environ["PORT"]))

    if "ENDPOINTS_SERVICE_PATH" in os.environ:
        ARGS.extend(
            [
               "--rollout_strategy=fixed",
               "--service_json_path={}".format(os.environ["ENDPOINTS_SERVICE_PATH"]),
            ]
        )
    else:
        try:
            assert_env_var(
                "ENDPOINTS_SERVICE_NAME",
                MISSING_SERVICE_CONFIG_ERROR
            )
        except AssertionError as error:
            serve_warning_msg(str(error))
        ARGS.append("--service={}".format(os.environ["ENDPOINTS_SERVICE_NAME"]))

        if "ENDPOINTS_SERVICE_VERSION" in os.environ:
            ARGS.extend(
                [
                    "--rollout_strategy=fixed",
                    "--version={}".format(os.environ["ENDPOINTS_SERVICE_VERSION"]),
                ]
            )
        else:
            ARGS.append("--rollout_strategy=managed")

    if "ESPv2_ARGS" in os.environ:
        # By default, ESPv2_ARGS is comma-separated.
        # But if a comma needs to appear within an arg, there is an alternative
        # syntax: Pick a replacement delimiter, specify it at the beginning of the
        # string between two caret (^) symbols, and use it within the arg string.
        # Example:
        # ^++^--cors_allow_methods="GET,POST,PUT,OPTIONS"++--cors_allow_credentials
        arg_value = os.environ["ESPv2_ARGS"]

        delim = ","
        if arg_value.startswith("^") and "^" in arg_value[1:]:
            delim, arg_value = arg_value[1:].split("^", 1)
        if not delim:
            serve_error_msg(MALFORMED_ESPv2_ARGS_ERROR)

        ARGS.extend(arg_value.split(delim))
    return ARGS