python mqtt request&response example request server

mqtt_request_server.py

#!/usr/bin/env python3

import paho.mqtt.client as mqtt

"""Example request:

mosquitto_rr -V mqttv5 -h localhost -p 1883 -t "test/topic" -m "Answer this!" -e "test/response"

"""

broker = {'host': "localhost", 'port': 1883}

def on_connect(client, userdata, flags, reason_code, properties):
    print(f"Connected with result code {reason_code}")
    client.subscribe("#", options=mqtt.SubscribeOptions(noLocal=True))

def on_message(client, userdata, msg):
    print("< ", msg.topic, " ", str(msg.payload))
    try:
        print("Responding to topic: ", str(msg.properties.ResponseTopic))
        client.publish(msg.properties.ResponseTopic, "This is your response")
    except:
        pass

mqttc = mqtt.Client(mqtt.CallbackAPIVersion.VERSION2, protocol=mqtt.MQTTProtocolVersion.MQTTv5)
mqttc.on_connect = on_connect
mqttc.on_message = on_message

mqttc.connect(broker['host'], broker['port'], 60)

mqttc.loop_forever()