Docker_installation.md

Steps to install Docker on your Jenkins Server

1) First, update your existing list of packages using the command "sudo apt update"
2) Next, install a few prerequisite packages which let apt use packages over HTTPS using the command "sudo apt install apt-transport-https ca-certificates curl software-properties-common"
3) Then add the GPG key for the official Docker repository to your system using the command "curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -"
4) Add the Docker repository to APT sources using the command "sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu bionic stable" "
5) Next, update the package database with the Docker packages from the newly added repo using the command "sudo apt update"
6) To Make sure you are about to install from the Docker repo instead of the default Ubuntu repo use the command "apt-cache policy docker-ce"
7) Install docker using the command "sudo apt install docker-ce"
8) To check whether docker is running or not use the command "sudo systemctl status docker"
9) Create a user called dockeradmin by using the commands "useradd dockeradmin" and "passwd dockeradmin".
10) Then add the user to the group by using the command "usermod -aG docker dockeradmin"