def main()

in ghd-notifier.py [0:0]

• 21 lines of code
• 7 McCabe index (conditional complexity)

def main():

    # Grab all GitHub WebHook IP ranges and save them, so we can check if an
    # incoming request is originating from one of these IP addresses.
    webhook_ips = requests.get("https://api.github.com/meta").json()["hooks"]
    allowed_ips = [netaddr.IPNetwork(ip) for ip in webhook_ips]

    # Init Flask...
    app = flask.Flask(__name__)

    # This will make Flask react to requests aimed at /hook, which the GitHub
    # webhook service will be calling.
    @app.route("/hook", methods=["POST", "PUT"])
    def parse_request():
        # Get the IP address, the request is originating from.
        # (I assume the "X-Forwarded-For" is used when using tools like ngrok
        # to forward requests to protected locations, "flask.request.remote_addr"
        # contains the ip in the direct access case)
        this_ip = netaddr.IPAddress(flask.request.headers.get("X-Forwarded-For") or flask.request.remote_addr)

        # Check if this incoming request is originating from one of the
        # GitHub webhook IP addresses. Deny the request, if it's not.
        allowed = any(this_ip in ip for ip in allowed_ips)
        if not allowed:
            return "No content\n"

        # Process the incoming message.
        content = flask.request.json
        # GitHub Discussion notifications are all expected to have a "discussion" element.
        if "discussion" in content:
            # If this is a comment action, it will also contain a "comment" element
            if "comment" in content:
                logmsg = parse_comment_action(content)
            # Otherwise it's a basic "create", "edit", "close" operation.
            else:
                logmsg = parse_thread_action(content)
            log.log(level=logging.WARNING, msg=logmsg)
        return "Delivered\n"

    # Disable werkzeug request logging to stdout
    log = logging.getLogger("werkzeug")
    log.setLevel(logging.WARNING)

    # Start up the app (Starts the Flask webserver)
    app.run(host="127.0.0.1", port=8084, debug=False)