Disable Docker autostart at boot?

On the systems since Ubuntu 16.04+ (where OS uses systemd), according to the doc, autostart on boot can be turned off by:

$ sudo systemctl disable docker.service
$ sudo systemctl disable docker.socket

Note that if you do not disable the socket as well as the service then the service will get started anyways as the socket depends on it.

Ok, I think I managed to get it working, following How to enable or disable services?:

sudo bash -c 'echo manual | sudo tee /etc/init/docker.override'

Hope that was it...