Docker CE

1. Install yum-utils, which provides the yum-config-manager utility:

   $ sudo yum install -y yum-utils
   

2. Use the following command to set up the stable repository:

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

3. Optional: Enable the edge repository. This repository is included in the docker.repo file above but is disabled by default. You can enable it alongside the stable repository.

   $ sudo yum-config-manager --enable docker-ce-edge
   

   You can disable the edge 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 --disable docker-ce-edge
   

   Learn about stable and edge builds.

INSTALL DOCKER

1. Update the yum package index.

   $ sudo yum makecache fast
   

   If this is the first time you have refreshed the package index since adding the Docker repositories, you will be prompted to accept the GPG key, and the key’s fingerprint will be shown. Verify that the fingerprint is correct, and if so, accept the key.

   Docker Edition	Fingerprint
   Docker CE	060A 61C5 1B55 8A7F 742B 77AA C52F EB6B 621E 9F35
   Docker EE	DD91 1E99 5A64 A202 E859 07D6 BC14 F10B 6D08 5F96

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

   Docker Edition	Command
   Docker CE	sudo yum install docker-ce
   Docker EE	sudo yum install docker-ee

   Warning: If you have multiple Docker repositories enabled, installing or updating without specifying a version in the yum install or yum 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. List the available versions. This example uses the sort -r command to sort the results by version number, highest to lowest, and is truncated.

   Note: This yum list command only shows binary packages. To show source packages as well, omit the .x86_64 from the package name.

   $ yum list docker-ce.x86_64  --showduplicates |sort -r
   
   docker-ce.x86_64  17.03.0.el7                               docker-ce-stable  
   

   The contents of the list depend upon which repositories are 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. 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 (-):

   Docker Edition	Command
   Docker CE	sudo yum install docker-ce-<VERSION>
   Docker EE	sudo yum install docker-ee-<VERSION>

4. Start Docker.

   $ sudo systemctl start docker
   

5. 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.

在CentOS 7 上安装docker