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-common\docker-selinux\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 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 RPM 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

Install required packages. yum-utils provides the yum-config-manager utility, and device-mapper-persistent-data and lvm2are required by the devicemapper storage driver.

$ sudo yum install-yyum-utils\device-mapper-persistent-data\lvm2

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.

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

Optional: Enable the edge and test repositories. These repositories are included in the docker.repo file above but are disabled by default. You can enable them alongside the stable repository.

$ sudo yum-config-manager--enabledocker-ce-edge

$ sudo yum-config-manager--enabledocker-ce-test

You can disable the edge or test repository by running the yum-config-manager command with the --disable flag. To re-enable it, use the --enable flag. The following command disables the edge repository.

$ sudo yum-config-manager--disabledocker-ce-edge

Note: Starting with Docker 17.06, stable releases are also pushed to the edge and test repositories.

Learn about stable and edge builds.

INSTALL DOCKER CE

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

$ sudo yum install docker-ce

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

If this is the first time you are installing a package from a recently added repository, you are prompted to accept the GPG key, and the key’s fingerprint is shown. Verify that the fingerprint is correct, and if so, accept the key. The fingerprint should match060A 61C5 1B55 8A7F 742B 77AA C52F EB6B 621E 9F35.

Docker is installed but not started. The docker group is created, but no users are added to the group.

On production systems, you should install a specific version of Docker CE instead of always using the latest. List the available versions. This example uses the sort -r command to sort the results by version number, highest to lowest, and is truncated.

$ yum list docker-ce--showduplicates| sort-rdocker-ce.x86_64            17.12.ce-1.el7.centos            docker-ce-stable

The contents of the list depend upon which repositories are enabled, and are specific to your version of CentOS (indicated by the .el7 suffix on the version, in this example). Choose a specific version to install. The second column is the version string. You can use the entire version string, but you need to include at least to the first hyphen. 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 a hyphen (-).

Note: The version string is the package name plus the version up to the first hyphen. In the example above, the fully qualified package name is docker-ce-17.06.1.ce.

$ sudo yum install

Start Docker.

systemctl enable docker

$ sudo systemctl start docker

Verify that docker 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 CE 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 CE

To upgrade Docker CE, follow the installation instructions, choosing the new version you want to install.