This example starts four tortoise clients,
:d who subscribe to the same shared topic:
bar. Notice that the client expect a broker running on localhost, on port 1883, and accept username/password less connections.
Start the example by typing
MqttTest.start() in an iex session; now one can observe the name of the receiving client change when a message is posted to the
Tortoise.publish(:a, "bar", "hello")