Mosquitto

Introduction

Mosquitto is an open-source messaging broker that implements MQTT on data coming from IoT devices, by implementing the MQTT protocol. It is lightweight and is suitable for use on all devices from low power single board computers to high performance compute servers.

--(Eclipse Foundation 2022)

Install Mosquitto with Docker

To install mosquitto using a docker compose file to setup a container, define a docker-compose file like below.

 version: "3"
services:
  broker:
    image: eclipse-mosquitto
    volumes:
      - "./mosquitto:/mosquitto"
      - "./mosquitto/config:/mosquitto/config"
      - "./mosquitto/data:/mosquitto/data"
      - "./mosquitto/log:/mosquitto/log"
    ports:
      - "1883:1883"
      - "9001:9001"

Some notes about the configurations:

version depends on the schema of the compose file and compose runtime.
broker is the name of the sole service being run in this container pod.
image is the name of the docker image to be used.
volumes are the directories to be mounted in the container, there's a few...
- mosquitto is the root directory of the mosquitto installation, which is located in the same parent directory as the compose file.
- config is the directory where the configuration file is located.
- data is the directory where the data is stored.
- log is the directory where the log files are stored.
ports are the ports to be exposed by the container.
- 1883 is the port used by mosquitto for MQTT communication.
- 9001 is the port used by mosquitto for websockets communication.

Configure Mosquitto

Example Configuration

Here's an example configuration that can be used in the example from before. There's other sections to describe some of the configuration keys. The format is just a simple non-spaced key name, followed by a space and a configuration value.

allow_anonymous true
listener 1883
persistence false
persistence_location /mosquitto/data
log_dest file /mosquitto/log/mosquitto.log

allow_anonymous

This specifies whether anonymous connections are allowed.
The default is true.

listener

This specifies the port to listen on.
The default is 1883.

persistence

This specifies whether persistence is enabled.
The default is false.

persistence_location

This specifies the directory where persistence data is stored.
The default is /mosquitto/data.

log_dest

This specifies the destination for log messages.
The default is stderr.
To log to a file, use log_dest file /path/to/file.

References

Web Links

Eclipse Foundation. "Eclipse Home". mosquitto.org Jun 29. 2023