Docker Getting started with Docker Installing Docker on Ubuntu

Example

Requirements: Docker can be installed on any Linux with a kernel of at least version 3.10. Docker is supported on the following 64-bit versions of Ubuntu Linux:

• Ubuntu Xenial 16.04 (LTS)
• Ubuntu Wily 15.10
• Ubuntu Trusty 14.04 (LTS)
• Ubuntu Precise 12.04 (LTS)

Easy Installation

Note: Installing Docker from the default Ubuntu repository will install an old version of Docker.

To install the latest version of Docker using the Docker repository, use curl to grab and run the installation script provided by Docker:

$ curl -sSL https://get.docker.com/ | sh

Alternatively, wget can be used to install Docker:

$ wget -qO- https://get.docker.com/ | sh

Docker will now be installed.

Manual Installation

If, however, running the installation script is not an option, the following instructions can be used to manually install the latest version of Docker from the official repository.

$ sudo apt-get update
$ sudo apt-get install apt-transport-https ca-certificates

Add the GPG key:

$ sudo apt-key adv --keyserver hkp://p80.pool.sks-keyservers.net:80 \
  --recv-keys 58118E89F3A912897C070ADBF76221572C52609D

Next, open the /etc/apt/sources.list.d/docker.list file in your favorite editor. If the file doesn’t exist, create it. Remove any existing entries. Then, depending on your version, add the following line:

• Ubuntu Precise 12.04 (LTS):

  deb https://apt.dockerproject.org/repo ubuntu-precise main

• Ubuntu Trusty 14.04 (LTS)

  deb https://apt.dockerproject.org/repo ubuntu-trusty main

• Ubuntu Wily 15.10

  deb https://apt.dockerproject.org/repo ubuntu-wily main

• Ubuntu Xenial 16.04 (LTS)

  deb https://apt.dockerproject.org/repo ubuntu-xenial main

Save the file and exit, then update your package index, uninstall any installed versions of Docker, and verify apt is pulling from the correct repo:

$ sudo apt-get update
$ sudo apt-get purge lxc-docker
$ sudo apt-cache policy docker-engine

Depending on your version of Ubuntu, some prerequisites may be required:

• Ubuntu Xenial 16.04 (LTS), Ubuntu Wily 15.10, Ubuntu Trusty 14.04 (LTS)

  sudo apt-get update && sudo apt-get install linux-image-extra-$(uname -r)

• Ubuntu Precise 12.04 (LTS)

  This version of Ubuntu requires kernel version 3.13. You may need to install additional packages depending on your environment:

  linux-image-generic-lts-trusty

  Generic Linux kernel image. This kernel has AUFS built in. This is required to run Docker.

  linux-headers-generic-lts-trusty

  Allows packages such as ZFS and VirtualBox guest additions which depend on them. If you didn’t install the headers for your existing kernel, then you can skip these headers for the trusty kernel. If you’re unsure, you should include this package for safety.

  xserver-xorg-lts-trusty

  libgl1-mesa-glx-lts-trusty

  These two packages are optional in non-graphical environments without Unity/Xorg. Required when running Docker on machine with a graphical environment.

  To learn more about the reasons for these packages, read the installation instructions for backported kernels, specifically the LTS Enablement Stack — refer to note 5 under each version.

  Install the required packages then reboot the host:

  $ sudo apt-get install linux-image-generic-lts-trusty

  $ sudo reboot

Finally, update the apt package index and install Docker:

$ sudo apt-get update
$ sudo apt-get install docker-engine

Start the daemon:

$ sudo service docker start

Now verify that docker is running properly by starting up a test image:

$ sudo docker run hello-world

This command should print a welcome message verifying that the installation was successful.