There are a number of ways to install Docker. Pick your favorite.
On Mac from docker.com with .app: https://docs.docker.com/docker-for-mac/install/
On Windows from docker.com: https://docs.docker.com/docker-for-windows/install/
On Ubuntu: https://docs.docker.com/install/linux/docker-ce/ubuntu/
NOTE: If you plan to use a VPN, do NOT use the Docker Toolbox for Mac or the docker from Macports as these require a network socket that breaks when you install some VPN software. To understand the difference, check out this page.
If there are updates to the image, you can pull a new one from the hub with:
This is not automatically done, so if you have a problem, make sure you are up-to-date.
You can run the build script to build a local image:
If you want to change things, modify the openram-ubuntu/Dockerfile and let me know what should be fixed.