Easy way to install Docker on Ubuntu (without using packaging manager)
Step 1: Check if curl is installed
which curl
sudo apt-get update
Step 1b: If Curl is not installed install it
sudo apt-get install curl
Step 2: Get the latest Docker package
curl -fsSL https://get.docker.com/ | sh
Step 3: add user to docker group
sudo usermod -aG docker username
log out and back in
Step 4: Verify docker is installed
sudo status docker
sudo start docker
docker info
docker run hello-world
docker images
Step 5: (optional) download a ubunutu image
docker search ubuntu
docker pull ubuntu
docker run -it ubuntu