i tryed, but I get these errors in the test machine:
2019-09-30 13:15:23 WARNING (MainThread) [homeassistant.components.mqtt] Data in your config entry is going to override your configuration.yaml: {'broker': 'core-mosquitto', 'discovery': False, 'password': 'xxxx', 'port': 1883, 'protocol': '3.1.1', 'username': 'homeassistant'}
2019-09-30 13:15:24 ERROR (MainThread) [homeassistant.components.mqtt] Failed to connect due to exception: [Errno 111] Connection refused
2019-09-30 13:15:24 WARNING (MainThread) [homeassistant.config_entries] Config entry for mqtt not ready yet. Retrying in 5 seconds.
my configuration is simply:
mqtt:
broker: <production raspberry ip>
port: 1883
username: mqtt-user
password: <my password>