Example code for how to use Paho to connect to an MQTT server (such as Mosquitto).

paho-connect-wott.py

#!/usr/bin/env python

import paho.mqtt.client as mqtt

def on_connect(client, obj, flags, rc):
    print("rc: " + str(rc))

def on_message(client, obj, msg):
    print(msg.topic + " " + str(msg.qos) + " " + str(msg.payload))

def on_subscribe(client, obj, mid, granted_qos):
    print("Subscribed: " + str(mid) + " " + str(granted_qos))

client = mqtt.Client()
client.on_connect = on_connect
client.on_message = on_message
client.on_subscribe = on_subscribe

client.tls_set(
    ca_certs='/opt/wott/certs/ca.crt',
    certfile='/opt/wott/certs/client.crt',
    keyfile='/opt/wott/certs/client.key'
)


# disables peer verification
# client.tls_insecure_set(True)

# Note that you need to map x.d.wott.local to the IP to the MQTT server
# in /etc/hosts as the hostname must match the CN in the certificate.
client.connect('x.d.wott.local', 8883, 60)

client.subscribe('wott/temperature', 0)

client.loop_forever()