Get Docker EE for CentOS

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

Prerequisites

Docker CE users should go to Get docker CE for CentOS instead of this topic.

Docker EE repository URL

To install Docker Enterprise Edition (Docker EE), you need to know the Docker EE repository URL associated with your trial or subscription. These instructions work for Docker EE for Centos and for Docker EE for Linux, which includes access to Docker EE for all Linux distributions. To get this information:

• Go to https://store.docker.com/my-content.
• Each subscription or trial you have access to is listed. Click the Setup button for Docker Enterprise Edition for Centos.
• Copy the URL from the field labeled Copy and paste this URL to download your Edition.

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 EE, you need a maintained version of CentOS 7. Archived versions aren’t supported or tested.

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

In addition, you must use the devicemapper storage driver if you use Docker EE. On production systems, you must use direct-lvm mode, which requires one or more dedicated block devices. Fast storage such as solid-state media (SSD) is recommended.

Uninstall old versions

Older versions of Docker were called docker or docker-engine. In addition, if you are upgrading from Docker CE to Docker EE, remove the Docker CE package.

$ sudo yum remove docker \
                  docker-common \
                  docker-selinux \
                  docker-engine-selinux \
                  docker-engine \
                  docker-ce

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 EE package is now called docker-ee.

Install Docker EE

You can install Docker EE 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.

Install using the repository

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

Set up the repository

1. Remove any existing Docker repositories from /etc/yum.repos.d/.

2. Temporarily store the Docker EE repository URL you noted down in the prerequisites in an environment variable. This will not persist when the current session ends.

   $ export DOCKERURL='<DOCKER-EE-URL>'
   

3. Store your Docker EE repository URL in a yum variable in /etc/yum/vars/. This command relies on the variable you stored in the previous step.

   $ sudo -E sh -c 'echo "$DOCKERURL/centos" > /etc/yum/vars/dockerurl'
   

4. Install required packages. yum-utils provides the yum-config-manager utility, and device-mapper-persistent-data and lvm2 are required by the devicemapper storage driver.

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

5. Use the following command to add the stable repository:

   $ sudo -E yum-config-manager \
       --add-repo \
       "$DOCKERURL/centos/docker-ee.repo"
   

Install Docker EE

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

   $ sudo yum -y install docker-ee
   

   If this is the first time you are installing a package from a recently added repository, you will be prompted to accept the GPG key, and the key’s fingerprint will be shown. Verify that the fingerprint matches 77FE DA13 1A83 1D29 A418 D3E8 99E5 FF2E 7668 2BC9 and if so, accept the key.

2. On production systems, you should install a specific version of Docker EE 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.

   $ sudo yum list docker-ee  --showduplicates | sort -r
   
   docker-ee.x86_64         17.06.ee.2-1.el7.centos          docker-ee-stable-17.06
   

   The contents of the list depend upon which repositories you have enabled, and will be 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-ee-17.06.1.ee.2.

   $ sudo yum -y install <FULLY-QUALIFIED-PACKAGE-NAME>
   

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

3. Edit /etc/docker/daemon.json. If it does not yet exist, create it. Assuming that the file was empty, add the following contents.

   {
     "storage-driver": "devicemapper"
   }
   

4. For production systems, you must use direct-lvm mode, which requires you to prepare the block devices. Follow the procedure in the devicemapper storage driver guide before starting Docker.

5. Start Docker.

   $ sudo systemctl start docker
   

6. Verify that 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 EE 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 EE

To upgrade Docker EE:

1. If upgrading to a new major Docker EE version (such as when going from Docker 17.03.x to Docker 17.06.x), add the new repository.

2. Follow the installation instructions, choosing the new version you want to install.

Install from a package

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

1. Go to the Docker EE repository URL associated with your trial or subscription in your browser. Go to centos/7/x86_64/stable-17.06/Packages and download the .rpm file for the Docker version you want to install.

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

   $ sudo yum install /path/to/package.rpm
   

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

3. Edit /etc/docker/daemon.json. If it does not yet exist, create it. Assuming that the file was empty, add the following contents.

   {
     "storage-driver": "devicemapper"
   }
   

4. For production systems, you must use direct-lvm mode, which requires you to prepare the block devices. Follow the procedure in the devicemapper storage driver guide before starting Docker.

5. Start Docker.

   $ sudo systemctl start docker
   

6. Verify that 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 EE 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 EE

To upgrade Docker EE, download the newer package file and repeat the installation procedure, using yum -y upgrade instead of yum -y install, and pointing to the new file.

Uninstall Docker EE

1. Uninstall the Docker EE package:

   $ sudo yum -y remove 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
   

3. If desired, remove the devicemapper thin pool and reformat the block devices that were part of it.

You must delete any edited configuration files manually.

Next steps

• Continue to Post-installation steps for Linux

• Continue with the User Guide.