allowing more extensibility to customize the mqtt events logged in th…

…e database (#173)

* allowing more extensibility in order to be able to customize the mqtt events logged in the database

* fixed syntax issue

* added example with simple custom Mqtt client implementation

* removed unrequired override of initializer

* removed unrequired dependencies

examples/mqtt_custom_client_ex.py

@@ -0,0 +1,33 @@
+import time
+import typing
+
+from locust import task, TaskSet
+from locust_plugins.users.mqtt import MqttUser
+from locust_plugins.users.mqtt import MqttClient
+
+
+# extend the MqttClient class with your own custom implementation
+class MyMqttClient(MqttClient):
+
+    # you can override the event name with your custom implementation
+    def _generate_event_name(self, event_type: str, qos: int, topic: str):
+        return f"mqtt:{event_type}:{qos}"
+
+
+class MyUser(MqttUser):
+    # override the client_cls with your custom MqttClient implementation
+    client_cls: typing.Type[MyMqttClient] = MyMqttClient
+
+    @task
+    class MyTasks(TaskSet):
+        # Sleep for a while to allow the client time to connect.
+        # This is probably not the most "correct" way to do this: a better method
+        # might be to add a gevent.event.Event to the MqttClient's on_connect
+        # callback and wait for that (with a timeout) here.
+        # However, this works well enough for the sake of an example.
+        def on_start(self):
+            time.sleep(5)
+
+        @task
+        def say_hello(self):
+            self.client.publish("hello/locust", b"hello world")

locust_plugins/users/mqtt.py

@@ -117,6 +117,9 @@ def __init__(
         self._publish_requests: dict[int, PublishedMessageContext] = {}
         self._subscribe_requests: dict[int, SubscribeContext] = {}
 
+    def _generate_event_name(self, event_type: str, qos: int, topic: str):
+        return _generate_mqtt_event_name(event_type, qos, topic)
+
     def _on_publish_cb(
         self,
         client: mqtt.Client,
@@ -143,7 +146,7 @@ def _on_publish_cb(
             # fire successful publish event
             self.environment.events.request.fire(
                 request_type=REQUEST_TYPE,
-                name=_generate_mqtt_event_name("publish", request_context.qos, request_context.topic),
+                name=self._generate_event_name("publish", request_context.qos, request_context.topic),
                 response_time=(cb_time - request_context.start_time) * 1000,
                 response_length=request_context.payload_size,
                 exception=None,
@@ -180,7 +183,7 @@ def _on_subscribe_cb(
             if SUBACK_FAILURE in granted_qos:
                 self.environment.events.request.fire(
                     request_type=REQUEST_TYPE,
-                    name=_generate_mqtt_event_name("subscribe", request_context.qos, request_context.topic),
+                    name=self._generate_event_name("subscribe", request_context.qos, request_context.topic),
                     response_time=(cb_time - request_context.start_time) * 1000,
                     response_length=0,
                     exception=AssertionError(f"Broker returned an error response during subscription: {granted_qos}"),
@@ -193,7 +196,7 @@ def _on_subscribe_cb(
                 # fire successful subscribe event
                 self.environment.events.request.fire(
                     request_type=REQUEST_TYPE,
-                    name=_generate_mqtt_event_name("subscribe", request_context.qos, request_context.topic),
+                    name=self._generate_event_name("subscribe", request_context.qos, request_context.topic),
                     response_time=(cb_time - request_context.start_time) * 1000,
                     response_length=0,
                     exception=None,
@@ -287,7 +290,7 @@ def publish(
         if publish_info.rc != mqtt.MQTT_ERR_SUCCESS:
             self.environment.events.request.fire(
                 request_type=REQUEST_TYPE,
-                name=_generate_mqtt_event_name("publish", request_context.qos, request_context.topic),
+                name=self._generate_event_name("publish", request_context.qos, request_context.topic),
                 response_time=0,
                 response_length=0,
                 exception=publish_info.rc,
@@ -325,7 +328,7 @@ def subscribe(
         if result != mqtt.MQTT_ERR_SUCCESS:
             self.environment.events.request.fire(
                 request_type=REQUEST_TYPE,
-                name=_generate_mqtt_event_name("subscribe", request_context.qos, request_context.topic),
+                name=self._generate_event_name("subscribe", request_context.qos, request_context.topic),
                 response_time=0,
                 response_length=0,
                 exception=result,