Docker Installation

  Install Docker Engine on CentOS

To get started with Docker Engine on CentOS, make sure you meet the prerequisites, then install Docker.

Prerequisites

OS requirements

To install Docker Engine, you need a maintained version of CentOS 7. Archived versions aren’t supported or tested.

The centos-extras the repository must be enabled. This repository is enabled by default, but if you have disabled it, you need to re-enable it.

The overlay2 storage driver is recommended.

Uninstall old versions

Older versions of Docker were called docker or docker-engine. If these are installed, uninstall them, along with associated dependencies.

$ sudo yum remove docker \
                  docker-client \
                  docker-client-latest \
                  docker-common \
                  docker-latest \
                  docker-latest-logrotate \
                  docker-logrotate \
                  docker-engine

It’s OK if yum reports that none of these packages are installed.

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

SET UP THE REPOSITORY

Install the yum-utils package (which provides the yum-config-manager utility) and set up the stable repository.

$ sudo yum install -y yum-utils

$ sudo yum-config-manager \
    --add-repo \
    https://download.docker.com/linux/centos/docker-ce.repo

INSTALL DOCKER ENGINE

1. Install the latest version of Docker Engine and containerd, or go to the next step to install a specific version:

   $ sudo yum install docker-ce docker-ce-cli containerd.io
   

   If prompted to accept the GPG key, verify that the fingerprint matches 060A 61C5 1B55 8A7F 742B 77AA C52F EB6B 621E 9F35, and if so, accept it.

Install Docker Engine on Ubuntu

Estimated reading time: 11 minutes

To get started with Docker Engine on Ubuntu, make sure you meet the prerequisites, then install Docker.

Prerequisites

OS requirements

To install Docker Engine, you need the 64-bit version of one of these Ubuntu versions:

• Ubuntu Focal 20.04 (LTS)
• Ubuntu Eoan 19.10
• Ubuntu Bionic 18.04 (LTS)
• Ubuntu Xenial 16.04 (LTS)

Docker Engine is supported on x86_64 (or amd64), armhf, and arm64 architectures.

Uninstall old versions

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

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

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 Engine package is now called docker-ce.

Install using the repository

Before you install Docker Engine 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 and install packages to allow apt to use a repository over HTTPS:

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

2. 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   rsa4096 2017-02-22 [SCEA]
         9DC8 5822 9FC7 DD38 854A  E2D8 8D81 803C 0EBF CD88
   uid           [ unknown] Docker Release (CE deb) <docker@docker.com>
   sub   rsa4096 2017-02-22 [S]
   

3. Use the following command to set up the stable repository. To add the nightly or test repository, add the word nightly or test (or both) after the word stable in the commands below.

   Note: The lsb_release -cs sub-command below returns the name of your Ubuntu distribution, such as xenial. Sometimes, in a distribution like Linux Mint, you might need to change $(lsb_release -cs) to your parent Ubuntu distribution. For example, if you are using Linux Mint Tessa, you could use bionic. Docker does not offer any guarantees on untested and unsupported Ubuntu distributions.

   
   

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

INSTALL DOCKER ENGINE

1. Update the apt package index, and install the latest version of Docker Engine and containerd, or go to the next step to install a specific version:

    $ sudo apt-get update
    $ sudo apt-get install docker-ce docker-ce-cli containerd 

Install with apt Repoistory

apt update

apt install docker.io -y

Install Docker Desktop on Windows

Docker Desktop for Windows is the Community version of Docker for Microsoft Windows. You can download Docker Desktop for Windows from Docker Hub.

Download from Docker Hub

Test your installation

1. Open a terminal window (Command Prompt or PowerShell, but not PowerShell ISE).

2. Run docker --version to ensure that you have a supported version of Docker:

   > docker --version
   
   Docker version 19.03.1
   

3. Pull the hello-world image from Docker Hub and run a container:

   > docker run hello-world
   
   docker : Unable to find image 'hello-world:latest' locally
   latest: Pulling from library/hello-world
   1b930d010525: Pull complete
   Digest: sha256:c3b4ada4687bbaa170745b3e4dd8ac3f194ca95b2d0518b417fb47e5879d9b5f
   Status: Downloaded newer image for hello-world:latest
   
   Hello from Docker!
   This message shows that your installation appears to be working correctly.
   ...
   
   

4. List the hello-world image that was downloaded from Docker Hub:

   > docker image ls
   

5. List the hello-world container (that exited after displaying “Hello from Docker!”):

   > docker container ls --all
   

6. Explore the Docker help pages by running some help commands:

   > docker --help
   > docker container --help
   > docker container ls --help
   > docker run --help