Basics

to enable docker to start at startup:
sudo systemctl enable docker

to start docker:
sudo systemctl start docker

to check the version of docker:
sudo docker version

to install docker:
sudo apt-get update
sudo apt-get upgrade
sudo apt-get install -y docker.io

to search for "ubuntu" images:
sudo docker search ubuntu

to pull "ubuntu" image:
sudo docker pull ubuntu

to inspect the available on pc images:
sudo docker images

to inspect the running containers:
sudo docker ps

to inspect containers ready to run, but not running:
sudo docker ps -a

to create an "ubuntu" container:
sudo docker create ubuntu

to run a container and enter its bash immediately:
sudo docker run -i -t ubuntu /bin/bash

to run a container in the background:
sudo docker run -i -t -d ubuntu /bin/sh

to give a name to such a container:
sudo docker run -i -t -d --name nick ubuntu /bin/sh

to enter a certain container:
sudo docker exec -i -t nick /bin/bash

to stop a container:
sudo docker stop nick

to start a container:
sudo docker start nick

to remove a container:
sudo docker rm nick

to remove an image:
sudo docker rmi ubuntu

to create a network with the name "mynet":
sudo docker network create --subnet=172.18.0.0/16 mynet

to assign a static ip to a container:
sudo docker run --name attacker --net mynet --ip 172.18.0.4 -itd ubuntu bash