How to setup local MQTT in Bridge REMAP remote topics

Question

I am trying to setup MQTT bridge, where I want to publish all local topic to remote, but subscribe only certain remote topic which matches wild card and remap to local broker

Here is the config

 topic # out 2 "" UP/site1/
 topic DOWN/site1/# in 2 DOWN/ DOWN/site1/

local to remote publishing works perfectly, but remote to local mapping doesn't works.

I just want to pull topics with prefix DOWN/site1/# from remote to local broker and remove the prefix DOWN/site1/.

I am using cloudmqtt.com as remote and local MQTT (bridge) running on Raspberry Pi Zero.

Any help here ?

Answer 1

You want something like this for the last line:

topic # in 2 "" Down/site1/

This is because the first topic is relative to the last remote topic prefix.

The following example from the mosquitto docs will hopefully make it clearer:

The configuration below connects a bridge to the broker at test.mosquitto.org. It subscribes to the remote topic $SYS/broker/clients/total and republishes the messages received to the local topic test/mosquitto/org/clients/total

connection test-mosquitto-org
address test.mosquitto.org
cleansession true
topic clients/total in 0 test/mosquitto/org $SYS/broker/