As many of you know, starting January 1st, linuxserver.io is discontinuing Unifi-controller in favour of Unifi-Network-Application.
Getting it to work is a bit more difficult than before, mainly because it requires an external mongodb instance.
I deployed it succesfully on a Raspberry Pi 3 running DietPI, you can find instructions along with the compose file at https://github.com/GiuseppeGalilei/Ubiquiti-Tips-and-Tricks.
Feel free to share your experiences and questions! And if you found it useful, star the repo on github
PS: Thanks for the awesome project and happy holidays!