Identity

Unit: mosquitto.service
Daemon: mosquitto
Config: /etc/mosquitto/mosquitto.conf, /etc/mosquitto/conf.d/
Logs: journalctl -u mosquitto, /var/log/mosquitto/mosquitto.log
User: mosquitto
Distro install: apt install mosquitto mosquitto-clients / dnf install mosquitto

Key Operations

Operation	Command
Service status	`systemctl status mosquitto`
Test publish	`mosquitto_pub -h localhost -t test/topic -m "hello"`
Test subscribe	`mosquitto_sub -h localhost -t test/topic -v`
Subscribe all topics (wildcard)	`mosquitto_sub -h localhost -t '#' -v`
Subscribe single-level wildcard	`mosquitto_sub -h localhost -t 'sensors/+/temperature' -v`
Show connected clients	`mosquitto_sub -h localhost -t '$SYS/broker/clients/connected' -C 1`
Check connections count	`mosquitto_sub -h localhost -t '$SYS/broker/clients/total' -C 1`