This is a fork of the original node-red mqtt node with the added feature that the broker address can resolve environment variables. This allows for semi dynamic changeing of brokers without changing the actual flow that is loaded by node-red.
Credits to artcom for his node-red-contrib-mqtt-env node that is built on the same idea. A new node was created because this inital node by artcom dosen't seem to be under development as it is built on the old mqtt node that now is deprecated. Also a difference between artcoms node and this one is that this node can resolve several env variables and will concatinate it into the broker url.
Run the following command in your node-red directory.
npm install node-red-contrib-mqttenv
Before running node-red make sure that you have an environment variable set. eg
Add a mqttenv node to your flow. Configure a mqtt broker as per usual. Then in the Server field where you would enter the url you can add your environment varibles eg.
%FOO%.server.com which once the node is running will be resolved to