sudo apt install mosquitto mosquitto-clients mosquitto-dev

Stop and disable mosquitto server for now. Later start it using `runit'

/etc/init.d/mosquitto stop
update-rc.d mosquitto disable
systemctl disable mosquitto
systemctl mask mosquitto

Create and edit local config

vi /etc/mosquitto/conf.d/local.conf

Add the following

listener 1883
allow_anonymous true

Create password file and add a user

touch /etc/mosquitto/pwfile
mosquitto_passwd -b /etc/mosquitto/pwfile username password

Create and edit local config

vi /etc/mosquitto/conf.d/local.conf

Add the following

allow_anonymous false

#! /bin/bash
sleep 1

mkdir -p /var/lib/mosquitto
chown -R mosquitto:mosquitto /var/lib/mosquitto

mkdir -p /var/log/mosquitto
chown -R mosquitto:mosquitto /var/log/mosquitto

mkdir -p /run/mosquitto
chown -R mosquitto:mosquitto /run/mosquitto

exec /usr/sbin/mosquitto -c /etc/mosquitto/mosquitto.conf

MQTT host is listening at 192.168.0.13

mosquitto_sub -h 192.168.0.13 -t '#'