MQTT broker
% docker run -it --name mosquitto -p 1883:1883 eclipse-mosquitto
1582194844: mosquitto version 1.6.8 starting
1582194844: Config loaded from /mosquitto/config/mosquitto.conf.
1582194844: Opening ipv4 listen socket on port 1883.
1582194844: Opening ipv6 listen socket on port 1883.