add Option to only get Gateway

wgkex/broker/app.py

@@ -51,6 +51,30 @@ def from_dict(cls, msg: dict) -> "KeyExchange":
             raise ValueError(f"Domain {domain} not in configured domains.")
         return cls(public_key=public_key, domain=domain)
 
+@dataclasses.dataclass
+class Gateway:
+    """A best Gateway message.
+
+    Attributes:
+        domain: The domain for the best Gateway.
+    """
+
+    domain: str
+
+    @classmethod
+    def from_dict(cls, msg: dict) -> "Gateway":
+        """Creates a new Gateway message from dict.
+
+        Arguments:
+            msg: The message to convert.
+        Returns:
+            A Gateway object.
+        """
+        domain = str(msg.get("domain"))
+        if not is_valid_domain(domain):
+            raise ValueError(f"Domain {domain} not in configured domains.")
+        return cls(domain=domain)
+
 
 def _fetch_app_config() -> Flask_app:
     """Creates the Flask app from configuration.
@@ -160,6 +184,58 @@ def wg_api_v2_key_exchange() -> Tuple[Response | Dict, int]:
     return {"Endpoint": endpoint}, 200
 
 
+@app.route("/api/v2/wg/gateway/best", methods=["POST"])
+def wg_api_v2_gateway_best() -> Tuple[Response | Dict, int]:
+    """Retrieves a site, validates it and responds with a worker/gateway the client should connect to.
+
+    Returns:
+        Status message, Endpoint with address/domain, port.
+    """
+    try:
+        data = Gateway.from_dict(request.get_json(force=True))
+    except Exception as ex:
+        return {"error": {"message": str(ex)}}, 400
+
+    domain = data.domain
+    # in case we want to decide here later we want to publish it only to dedicated gateways
+    gateway = "all"
+    logger.info(f"wg_api_v2_gateway_best: Domain: {domain}")
+
+
+    best_worker, diff, current_peers = worker_metrics.get_best_worker(domain)
+    if best_worker is None:
+        logger.warning(f"No worker online for domain {domain}")
+        return {
+            "error": {
+                "message": "no gateway online for this domain, please check the domain value and try again later"
+            }
+        }, 400
+
+    # Update number of peers locally to interpolate data between MQTT updates from the worker
+    # TODO fix data race
+    current_peers_domain = (
+        worker_metrics.get(best_worker)
+        .get_domain_metrics(domain)
+        .get(CONNECTED_PEERS_METRIC, 0)
+    )
+
+    logger.debug(
+        f"Chose worker {best_worker} with {current_peers} connected clients ({diff})"
+    )
+
+    w_data = worker_data.get((best_worker, domain), None)
+    if w_data is None:
+        logger.error(f"Couldn't get worker endpoint data for {best_worker}/{domain}")
+        return {"error": {"message": "could not get gateway data"}}, 500
+
+    endpoint = {
+        "Address": w_data.get("ExternalAddress"),
+        "Port": str(w_data.get("Port")),
+    }
+
+    return {"Endpoint": endpoint}, 200
+
+
 @mqtt.on_connect()
 def handle_mqtt_connect(
     client: mqtt_client.Client, userdata: bytes, flags: Any, rc: Any