The broker on your own network

modbee alone, plain MQTT on port 1883, for devices on a LAN, a VPN or a private
cloud network. Every device has its own login and may use only the topics you
give it.

Not for the open internet - there is no TLS here. On the internet use
../traefik (it gets a free certificate) or ../npm
(you already run Nginx Proxy Manager). Want the messages in Kafka too? Use
../broker-kafka.

Start it

You need a Linux server with Docker, and these four files.

cp .env.example .env        # set MQTT_PASSWORD (a long one)
docker compose up -d
docker compose logs modbee  # "modbee serve: ... on 0.0.0.0 port 1883"

Devices connect to mqtt://<this server>:1883.

Add a device

docker compose exec modbee modbee user add tank-01 \
  --publish 'plant/${username}/#' --subscribe 'plant/${username}/cmd'

It prints the device's password, once. tank-01 may then publish under
plant/tank-01/... and receive plant/tank-01/cmd, nothing else. Rules and
everything else about logins: docs/logins.md.

Many devices of one kind? Let them register themselves with one key instead:

docker compose exec modbee modbee key create site-north --site north \
  --publish 'plant/${username}/#' --subscribe 'plant/${username}/cmd'

Each device signs in once with that key and its own name, and is given its own
login (docs/logins.md).

Check it works

docker compose exec modbee modbee sub -t 'plant/#' -v      # in one terminal
docker compose exec modbee modbee pub -t plant/test -m hi  # in another

Inside the container modbee uses the admin login by itself. From another
computer add -h <server> -u admin -P '<MQTT_PASSWORD>'.

Keep it running