install docker version 18.06 on ubuntu 18.04 code example
Example 1: how to install docker ubuntu
sudo apt-get update
sudo apt-get upgrade
sudo apt install docker.io
systemctl start docker
systemctl enable docker
docker --version
Example 2: install docker on ubuntu with
$ sudo add-apt-repository \
"deb [arch=amd64] https://download.docker.com/linux/ubuntu \
$(lsb_release -cs) \
stable"