def url_request_helper()

in src/watchdog/__init__.py [0:0]

• 37 lines of code
• 14 McCabe index (conditional complexity)

def url_request_helper(config, url, unsuccessful_resp, url_error_msg, headers={}):
    try:
        req = Request(url)
        for k, v in headers.items():
            req.add_header(k, v)

        if not fetch_ec2_metadata_token_disabled(config) and is_instance_metadata_url(
            url
        ):
            # https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/configuring-instance-metadata-service.html
            # IMDSv1 is a request/response method to access instance metadata
            # IMDSv2 is a session-oriented method to access instance metadata
            # We expect the token retrieve will fail in bridge networking environment (e.g. container) since the default hop
            # limit for getting the token is 1. If the token retrieve does timeout, we fallback to use IMDSv1 instead
            token = get_aws_ec2_metadata_token()
            if token:
                req.add_header("X-aws-ec2-metadata-token", token)

        request_resp = urlopen(req, timeout=1)

        return get_resp_obj(request_resp, url, unsuccessful_resp)
    except socket.timeout:
        err_msg = "Request timeout"
    except HTTPError as e:
        # For instance enable with IMDSv2 and fetch token disabled, Unauthorized 401 error will be thrown
        if (
            e.code == 401
            and fetch_ec2_metadata_token_disabled(config)
            and is_instance_metadata_url(url)
        ):
            logging.warning(
                "Unauthorized request to instance metadata url %s, IMDSv2 is enabled on the instance, while fetching "
                "ec2 metadata token is disabled. Please set the value of config item "
                '"%s" to "false" in config file %s.'
                % (url, DISABLE_FETCH_EC2_METADATA_TOKEN_ITEM, CONFIG_FILE)
            )
        err_msg = "Unable to reach the url at %s: status=%d, reason is %s" % (
            url,
            e.code,
            e.reason,
        )
    except URLError as e:
        err_msg = "Unable to reach the url at %s, reason is %s" % (url, e.reason)

    if err_msg:
        logging.debug("%s %s", url_error_msg, err_msg)
    return None