MOSQUITTO BROKER - allow support for Lua-Based Mosquitto Plugin

Feature Requests
1

I would like to be able to filter out invalid messages at the broker level.

For example, my temperature sensors which involve 4 entities (temperature, humidity, RSSI, batter) often get invalid data which I can detect by humidity > 100.

I would like to filter these out wholesale at the broker level by doing something like:

function acl_check(clientid, username, topic, payload, qos, retain)
    local json = require("cjson")  -- Make sure Lua JSON library is available
    local data = json.decode(payload)
    
    -- Reject if "humidity" exists and is greater than 100
    if data.humidity and tonumber(data.humidity) > 100 then
        return mosq.AUTH_DENIED
    end
    
    return mosq.AUTH_GRANTED
end

And then modifying mosquitto.conf by adding:

plugin /usr/lib/mosquitto/auth_plugin.so
auth_plugin /etc/mosquitto/auth_filter.lua

My understanding is that this is not possible currently since you can’t add plugins to the add-on.

Is that correct?
If so, is there any way to add the plugin capability to the broker add-on?

2

Hi puterboy.

I would suggest asking this here or contributing to make it work possibly.

Creating your own add-on is also possible.