Mosquitto

How to install and configure Mosquitto on Raspberry Pi.

sudo apt-get update
sudo apt-get upgrade
sudo apt-get install mosquitto mosquitto-clients

Once installation is completed, we need to create the mosquitto service (unless it is automatically built , while using Dietpi for example).

cd /etc/systemd/system
nano mosquitto.service

Paste the following:

[Unit]
Description=Mosquitto MQTT v3.1/v3.1.1 Broker
Documentation=man:mosquitto.conf(5) man:mosquitto(8)
After=network-online.target
Wants=network-online.target

[Service]
Type=notify
NotifyAccess=main
ExecStart=/usr/sbin/mosquitto -c /etc/mosquitto/mosquitto.conf
Restart=on-failure

[Install]
WantedBy=multi-user.target

and close the file with CTRL+x – Y.
Then enable the service (to start upon reboot)

systemctl enable mosquitto.service

Configuration file. Located in /etc/mosquitto or /etc/mosquitto/conf.d

# Place your local configuration in /etc/mosquitto/conf.d/
#
# A full description of the configuration file is at
# /usr/share/doc/mosquitto/examples/mosquitto.conf.example

pid_file /var/run/mosquitto.pid

persistence true
persistence_location /var/lib/mosquitto/

log_dest file /var/log/mosquitto/mosquitto.log

include_dir /etc/mosquitto/conf.d

Simple configuration file

# Config file for mosquitto
#
# See mosquitto.conf(5) for more information.


user mosquitto
max_queued_messages 200
message_size_limit 0
allow_zero_length_clientid true
allow_duplicate_messages false

listener 1883
autosave_interval 900
autosave_on_changes false
persistence true
persistence_file /var/lib/mosquitto/mosquitto.db
allow_anonymous true
password_file /etc/mosquitto/passwd

The password_file mentioned above is generated when adding/creating user for mosquitto. Add a username and password to a new password file (/etc/mosquitto/passwd):

mosquitto_passwd -c /etc/mosquitto/passwd username

This command will request to enter a password for the specified username, and place the results in /etc/mosquitto/passwd

To add a user and password to an existing password file, just run the following command:

mosquitto_passwd /etc/mosquitto/passwd username