Install docker on Ubuntu

https://docs.docker.com/install/linux/docker-ce/ubuntu/

Uninstall old versions

Older versions of Docker were called docker or docker-engine. If these are installed, uninstall them:

$ sudo apt-get remove docker docker-engine docker.io

It’s OK if apt-get reports that none of these packages are installed.

The contents of /var/lib/docker/, including images, containers, volumes, and networks, are preserved. The Docker CE package is now called docker-ce.

Install Docker CE

You can install Docker CE in different ways, depending on your needs:

• Most users set up Docker’s repositories and install from them, for ease of installation and upgrade tasks. This is the recommended approach.

• Some users download the DEB package and install it manually and manage upgrades completely manually. This is useful in situations such as installing Docker on air-gapped systems with no access to the internet.

• In testing and development environments, some users choose to use automated convenience scripts to install Docker.

Install using the repository

Before you install Docker CE for the first time on a new host machine, you need to set up the Docker repository. Afterward, you can install and update Docker from the repository.

SET UP THE REPOSITORY

1. Update the apt package index:

   $ sudo apt-get update
   

2. Install packages to allow apt to use a repository over HTTPS:

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

3. Add Docker’s official GPG key:

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

   Verify that you now have the key with the fingerprint 9DC8 5822 9FC7 DD38 854A E2D8 8D81 803C 0EBF CD88, by searching for the last 8 characters of the fingerprint.

   $ sudo apt-key fingerprint 0EBFCD88
   
   pub   4096R/0EBFCD88 2017-02-22
         Key fingerprint = 9DC8 5822 9FC7 DD38 854A  E2D8 8D81 803C 0EBF CD88
   uid                  Docker Release (CE deb) <docker@docker.com>
   sub   4096R/F273FCD8 2017-02-22
   

4. Use the following command to set up the stable repository. You always need the stable repository, even if you want to install builds from the edge or test repositories as well. To add the edge or test repository, add the word edge or test (or both) after the word stable in the commands below.
   

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

INSTALL DOCKER CE

1. Update the apt package index.

   $ sudo apt-get update
   

2. Install the latest version of Docker CE, or go to the next step to install a specific version:

   $ sudo apt-get install docker-ce

3. To install a specific version of Docker CE, list the available versions in the repo, then select and install:

   a. List the versions available in your repo:

   $ apt-cache madison docker-ce
   
   docker-ce | 18.03.0~ce-0~ubuntu | https://download.docker.com/linux/ubuntu xenial/stable amd64 Packages
   

   b. Install a specific version by its fully qualified package name, which is package name (docker-ce) “=” version string (2nd column), for example, docker-ce=18.03.0~ce-0~ubuntu.

   $ sudo apt-get install docker-ce=<VERSION>
   

   The Docker daemon starts automatically.

4. Verify that Docker CE is installed correctly by running the hello-world image.

   $ sudo docker run hello-world
   

   This command downloads a test image and runs it in a container. When the container runs, it prints an informational message and exits.

5. Add permission.

   $ sudo usermod -a -G docker $USER; shutdown -r now