How to install Docker CE on Ubuntu

Install required packages - these packages allow apt to use a repository over HTTPS

sudo apt-get update

sudo apt-get -y install \
  apt-transport-https \
  ca-certificates \
  curl \
  gnupg-agent \
  software-properties-common

Add the Docker GPG key and repo - with the GPG key (it’s a public key in an asymmetric encryption) the system can validate that the software to be downloaded from that repo is really coming from there.

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
    
sudo apt-key fingerprint 0EBFCD88

sudo add-apt-repository \
   "deb [arch=amd64] https://download.docker.com/linux/ubuntu \
   $(lsb_release -cs) \
   stable"

Update the repositories and Install Docker CE packages

sudo apt-get update

sudo apt-get install docker-ce docker-ce-cli

Add non-root users to docker group

sudo usermod -a -G docker <your_user>

check docker installation and version

sudo docker version

run a container test

docker run hello-world