Get Docker for Ubuntu

Estimated reading time: 10 minutes

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

Prerequisites

Docker EE customers

To install Docker Enterprise Edition (Docker EE), you need to know the Docker EE repository URL associated with your trial or subscription. To get this information:

  • Go to https://store.docker.com/?overlay=subscriptions.
  • Choose Get Details / Setup Instructions within the Docker Enterprise Edition for Ubuntu section.
  • Copy the URL from the field labeled Copy and paste this URL to download your Edition.

Where the installation instructions differ for Docker EE and Docker CE, use this URL when you see the placeholder text <DOCKER-EE-URL>.

To learn more about Docker EE, see Docker Enterprise Edition.

OS requirements

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

  • Yakkety 16.10
  • Xenial 16.04 (LTS)
  • Trusty 14.04 (LTS)

Docker CE is supported on both x86_64 and armhf architectures.

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

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, and the Docker EE package is now called docker-ee.

Unless you have a strong reason not to, install the linux-image-extra-* packages, which allow Docker to use the aufs storage drivers.

$ sudo apt-get update

$ sudo apt-get install \
    linux-image-extra-$(uname -r) \
    linux-image-extra-virtual

Install Docker

You can install Docker 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.

Install using the repository

Before you install Docker 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

The procedure for setting up the repository is different for Docker CE and Docker EE.

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

    $ sudo apt-get install \
        apt-transport-https \
        ca-certificates \
        curl \
        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 the key fingerprint is 9DC8 5822 9FC7 DD38 854A E2D8 8D81 803C 0EBF CD88.

    $ 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
    
  3. Use the following command to set up the stable repository. You always need the stable repository, even if you want to install edge builds as well.

    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 have to change $(lsb_release -cs) to your parent Ubuntu distribution. For example: If you are using Linux Mint Rafaela, you could use trusty.

    amd64:

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

    armhf:

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

    Learn about stable and edge channels.

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

    $ sudo apt-get install \
        apt-transport-https \
        ca-certificates \
        curl \
        software-properties-common
    
  2. Add Docker’s official GPG key using your customer Docker EE repository URL:

    $ curl -fsSL <DOCKER-EE-URL>/gpg | sudo apt-key add -
    

    Verify that the key fingerprint is DD91 1E99 5A64 A202 E859 07D6 BC14 F10B 6D08 5F96.

    $ apt-key fingerprint 0EBFCD88
    
    pub   4096R/6D085F96 2017-02-22
        Key fingerprint = DD91 1E99 5A64 A202 E859  07D6 BC14 F10B 6D08 5F96
    uid       [ultimate] Docker Release (EE deb) <docker@docker.com>
    sub   4096R/91A29FA3 2017-02-22
    
  3. Use the following command to set up the stable repository, replacing <DOCKER-EE-URL> with the URL you noted down in the prerequisites.

    Note: The lsb_release -cs sub-command below returns the name of your Ubuntu distribution, such as xenial.

    $ sudo add-apt-repository \
       "deb [arch=amd64] <DOCKER-EE-URL> \
       $(lsb_release -cs) \
       stable-17.03"
    

Install Docker

  1. Update the apt package index.

    $ sudo apt-get update
    
  2. Install the latest version of Docker, or go to the next step to install a specific version. Any existing installation of Docker is replaced.

    Use this command to install the latest version of Docker:

    $ sudo apt-get install docker-ce
    
    $ sudo apt-get install docker-ee
    

    Warning: If you have multiple Docker repositories enabled, installing or updating without specifying a version in the apt-get install or apt-get update command will always install the highest possible version, which may not be appropriate for your stability needs.

  3. On production systems, you should install a specific version of Docker instead of always using the latest. This output is truncated. List the available versions. For Docker EE customers, use docker-ee where you see docker-ce.

    $ apt-cache madison docker-ce
    
    docker-ce | 17.03.0~ce-0~ubuntu-xenial | https://download.docker.com/linux/ubuntu xenial/stable amd64 Packages
    

    The contents of the list depend upon which repositories are enabled, and will be specific to your version of Ubuntu (indicated by the xenial suffix on the version, in this example). Choose a specific version to install. The second column is the version string. The third column is the repository name, which indicates which repository the package is from and by extension its stability level. To install a specific version, append the version string to the package name and separate them by an equals sign (=):

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

    The Docker daemon starts automatically.

  4. Verify that Docker CE or Docker EE 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.

Docker is installed and running. You need to use sudo to run Docker commands. Continue to Linux postinstall to allow non-privileged users to run Docker commands and for other optional configuration steps.

Upgrade Docker

To upgrade Docker, first run sudo apt-get update, then follow the installation instructions, choosing the new version you want to install.

Install from a package

If you cannot use Docker’s repository to install Docker, you can download the .deb file for your release and install it manually. You will need to download a new file each time you want to upgrade Docker.

  1. This step is different for Docker CE and Docker EE.

    Go to https://download.docker.com/linux/ubuntu/dists/, choose your Ubuntu version, browse to pool/stable/, choose either amd64 or armhf,and download the .deb file for the Docker version you want to install and for your version of Ubuntu.

    Note: To install an edge package, change the word stable in the URL to edge. Learn about stable and edge channels.

    Go to the Docker EE repository URL associated with your trial or subscription in your browser. Go to x86_64/stable-17.03 and download the .deb file for the Docker version you want to install.

  2. Install Docker, changing the path below to the path where you downloaded the Docker package.

    $ sudo dpkg -i /path/to/package.deb
    

    The Docker daemon starts automatically.

  3. Verify that Docker CE or Docker EE 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.

Docker is installed and running. You need to use sudo to run Docker commands. Continue to Post-installation steps for Linux to allow non-privileged users to run Docker commands and for other optional configuration steps.

Upgrade Docker

To upgrade Docker, download the newer package file and repeat the installation procedure, pointing to the new file.

Uninstall Docker

  1. Uninstall the Docker package:

    $ sudo apt-get purge docker-ce
    
    $ sudo apt-get purge docker-ee
    
  2. Images, containers, volumes, or customized configuration files on your host are not automatically removed. To delete all images, containers, and volumes:

    $ sudo rm -rf /var/lib/docker
    

You must delete any edited configuration files manually.

Next steps

Docker, Docker documentation, requirements, apt, installation, ubuntu, install, uninstall, upgrade, update