KeyError while connectiong to a MQTT broker

Question

This is my code and on the bottom is the error I keep getting.

import configparser
from time import localtime, strftime
import json
import paho.mqtt.client as mqtt


config = configparser.ConfigParser()
config.read('/home/pi/bin/py.conf')     # Broker connection config.

requestTopic  = 'services/timeservice/request/+'        # Request comes in 
here. Note wildcard.
responseTopic = 'services/timeservice/response/'        # Response goes 
here. Request ID will be appended later

def onConnect(client, userdata, flags, rc):
   print("Connected with result code " + str(rc))

def onMessage(client, userdata, message):
   requestTopic = message.topic
   requestID = requestTopic.split('/')[3]       # obtain requestID as last 
field from the topic

   print("Received a time request on topic " + requestTopic + ".")

   lTime = strftime('%H:%M:%S', localtime())
   
   client.publish((responseTopic + requestID), payload=lTime, qos=0, 
retain=False)

def onDisconnect(client, userdata, message):
    print("Disconnected from the broker.")


# Create MQTT client instance
mqttc = mqtt.Client(client_id='raspberrypi', clean_session=True)

mqttc.on_connect = onConnect
mqttc.on_message = onMessage
mqttc.on_disconnect = onDisconnect

And after I try to connect to a broker:

mqttc.username_pw_set(config['MQTT']['userMQTT'], password=config['MQTT']['passwdMQTT'])
mqttc.connect(config['MQTT']['hostMQTT'], port=int(config['MQTT']['portMQTT']), keepalive=60, bind_address="")

I get the fallowing error:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3.5/configparser.py", line 956, in __getitem__
    raise KeyError(key)
KeyError: 'MQTT'

Does anybody know how to fix this error while trying to connect to a broker?

Answer 1

If you haven't created /home/pi/bin/py.conf... that's your problem.

config = configparser.ConfigParser()
config.read('/home/pi/bin/py.conf')

That code tries to open the file /home/pi/bin/py.conf and read it using an INI-like format. It turns that into a Python dict. Working back from the code, you need to add the following to /home/pi/bin/py.conf:

[MQTT]
userMQTT = username
passwdMQTT = password
hostMQTT = broker address
portMQTT = broker port

(filling in the details, of course)