01 / THE ROLE
In this lab.
Mosquitto runs as a containerised broker with persistent configuration and data. It connects producers and consumers using MQTT topics. It is distinct from Home Assistant, which provides application-level automation, and from Zigbee2MQTT, which bridges another device protocol.
02 / THE CONNECTIONS
Follow the flow.
- STEP 01Publisher
- STEP 02MQTT broker
- STEP 03Topic subscription
- STEP 04Consumer
03 / How it works
How it works.
Producers publish messages to topics and consumers subscribe to the topics they need. Retained messages, sessions and delivery settings can affect behaviour after restarts. The actual authentication and authorisation configuration is private and is not inferred from the existence of a broker container.
04 / Persistent data & recovery
Persistent data & recovery.
Classify broker configuration and persistent data according to the deployment. A broker that starts without its intended configuration is not equivalent to the previous service. Topic names and payloads can reveal device activity and are excluded from public examples.
05 / How to check it
How to check it.
A meaningful functional check uses a neutral test topic and controlled publisher/subscriber in an appropriate environment. Container state alone does not prove delivery, and an open connection does not prove the required topic permissions.
06 / Decisions & limits
Decisions & limits.
MQTT decouples producers and consumers, but troubleshooting must still follow the complete route. A working publisher does not prove that the intended subscriber received or acted on a message.