Answer by Shashank Rastogi for How do I install Docker on Ubuntu 16.04 LTS?

You can follow below steps to install docker-ce in Ubuntu -

1. install the dependencies first

   sudo apt install apt-transport-https ca-certificates curl software-properties-common

2. add the GPG key for the official Docker repository to the system:

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

3. Add the Docker repository in sources.list.d to APT sources using below command -

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

4. verify if you are able to install Docker from Docker repository

   apt-cache policy docker-ce

5. Finally, install Docker CE package with below command

   sudo apt-get install -y docker-ce

Voila, you have installed Docker-CE. You can verify installation by checking the version of docker-ce installed

docker --version

For more detailed instructions, follow this tutorial