Simple Paho MQTT Python Script to simultaneously publish/subscribe to a broker

mosquitto-broker.sh

#!/bin/bash

/usr/bin/docker run --name=mosquitto-broker -p 1883:1883 \
      -v $(pwd)/mosquitto/mosquitto.conf:/mosquitto/config/mosquitto.conf \
      eclipse-mosquitto:2.0

exit 0

mosquitto.conf

listener 1883 0.0.0.0
allow_anonymous true

pub-sub.py

import paho.mqtt.client as mqtt

import logging
import time

logging.basicConfig(level=logging.INFO)

logger = logging.getLogger(__name__)


UNIQUE_ID = "MY_UNIQUE_CLIENT_ID"
SUB_TOPIC = "sensors/test"
PUB_TOPIC = "sensors/data"
BROKER = 'localhost'
PORT = 1883

# Define Callbacks

def on_connect(mqttc, obj, flags, rc):
    if rc == 0:
        logger.debug(f"Connected to Broker with RC={rc}")
    else:
        logger.error(f"Error connecting to Broker")


def on_message(mqttc, obj, msg):
    logger.info(f"Incoming Message: {str(msg.payload)}")


def on_publish(mqttc, obj, mid):
    logger.info(f"Published Message with ID: {mid}")


def on_subscribe(mqttc, obj, mid, granted_qos):
    logger.debug(f"Subscribed: {mid}, qos={granted_qos}")


def on_disconnect(mqttc, obj, rc):
    if rc == 0:
        logger.debug(f"Disconnected from Broker with RC: {rc}")


def main():
    mqttc = mqtt.Client(client_id=UNIQUE_ID)

    mqttc.enable_logger(logger)

    mqttc.on_message = on_message
    mqttc.on_connect = on_connect
    mqttc.on_publish = on_publish
    mqttc.on_subscribe = on_subscribe

    logger.info("Connecting to MQTT Broker")

    mqttc.connect(BROKER,  PORT)

    logger.info("Subscribing to Topics")

    mqttc.subscribe(SUB_TOPIC, qos=0)
    mqttc.loop_start()
    try:
        loop = True
        while loop:
            try:
                time.sleep(6.0)
                mqttc.publish(PUB_TOPIC, "test")
            except:
                logger.error("error during publishing")
                loop = False
        
    except Exception as e:
        logger.error(f"Error:{e}")
        mqttc.disconnect()
        mqttc.loop_stop()


if __name__ == "__main__":
    main()