I have been using this set up with 5 esp8266 sensors from https://www.wemos.cc/. Tested even the update firmware OTA. working great.

Just remember to Change MQTT_MAX_PACKET_SIZE to 512 bytes on PubSubClient.h to allow for OTA

I created a simple Dockerfile project for mycontroller for my rpi. Clone the whole repo and follow the steps.
Why?

1. Docker helps me to handle porting mycontroller to a new rpi. ie works on a clean rpi without any java installed or other dependencies.
2. Docker helps me to handle auto startup on boot.
3. All other docker advantages.

https://github.com/wengjjpaul/dockers-rpi-mycontroller