Instructions followed from here. Some changes were made
Commands work on Ubuntu 16.04

Install Docker

sudo apt install -y docker docker.io
systemctl enable docker
systemctl start docker

Install UniFi

sudo docker pull jacobalberty/unifi:latest

Setup Docker Image

The following command sets up a container which we can later manipulate to start and stop the “service”
You can specify where you want the UniFi files to reside if desired.

sudo docker run -d --init --restart=unless-stopped --name=unifi-controller --net=host --volume=/docker/unifi:/var/lib/unifi -p 8080:8080/tcp -p 8081:8081/tcp -p 8443:8443/tcp -p 8843:8843/tcp -p 8880:8880/tcp -p 8883:8883/tcp -p 3478:3478/udp jacobalberty/unifi:latest

Docker commands

List docker containers

sudo docker container list
367c7a1465ec        jacobalberty/unifi:latest   "/usr/loca/bin/dock…" 15 minutes ago      Up 14 minutes (healthy) unifi-controller

List docker images on system

sudo docker images
jacobalberty/unifi   latest              baebbe301633        9 days ago          711MB

Stop container. Also stops the UniFi service. Change the ID to your container ID.

sudo docker stop 367c7a1465ec

Other notes

When setting up the Docker image, the directory specified was “/docker/unifi” so all the UniFi files are in there and it looks like if you manipulate the files, it makes the changes fine. At least for setting up the SSL certificates.