eolas/zk/mosquitto_mqtt_client.md

tags
Linux Debian mqtt

Config

At /etc/mosquitto/mosquitto.conf.

Most important lines:

listener 1883
allow_anonymous true

This means mosquitto will run on port:1883 and that I am not using authentication with requests to the broker.

Websockets

In order to enable websockets, must create a config file at /etc/mosquitto/mosquitto.conf/websockets.conf:

# /etc/mosquitto/mosquitto.conf/websockets.conf`
listener 8083
protocol websockets

This is only relevant if you require access from outside of the local network.

Basic usage

Create a topic

mosquitto_sub -d -t test_topic

This then enters listening mode and takes control of terminal:

$ mosquitto_sub -d -t test_topic
Client (null) sending CONNECT
Client (null) received CONNACK (0)
Client (null) sending SUBSCRIBE (Mid: 1, Topic: test_topic, QoS: 0, Options: 0x00)
Client (null) received SUBACK
Subscribed (mid: 1): 0

Publish to a topic

From my other machine I install mosquitto and:

mosquitto_pub --host 192.168.68.53 --port 1883 --topic test_topic --message 'hello world'

This registers on the broker device:

Client (null) received PUBLISH (d0, q0, r0, m0, 'test_topic', ... (11 bytes))
hello world