Step 1: docker network create -d overlay --attachable edge
Step 2: Run docker-compose up in Terminal#1 to start mosquitto broker which is connected to that network 'edge'
Step 3: Run run_subscriber.sh in Terminal#2 to run an mqtt subscriber container which has subscribed to the topic 'python/mqtt'
Step 4: Run run_python.sh in Terminal#3 to run an mqtt publisher (the python script in this directory) which publishes to the topic 'python/mqtt'
Step 5: Observe Terminal#2 as it receives the messages sent by the python script in Terminal#3