centos7 docker installation

 Reprinted from https://www.cnblogs.com/baolong/p/6526591.html

System Requirements

In order to install docker, you need to prepare 64-bit CentOS 7

Remove unofficial Docker packages

There is an old Docker package in the yum repository, and now Docker has officially renamed Docker to docker-engine. If you have installed this version of Docker, you need to use the following command to delete it

$ sudo yum -y remove docker docker-common container-selinux

/var/lib/dockerNo need to delete.

Install Docker

There are two ways to provide installation to docker.

Use yum method

Set up Docker repository

• Use the command below to set up the latest stable version of the docker repository

$ sudo yum-config-manager \
    --add-repo \
    https://docs.docker.com/v1.13/engine/installation/linux/repo_files/centos/docker.repo

Install Docker

• update yum source

$ sudo yum makecache fast

• Install the latest version of docker

$ sudo yum -y install docker-engine

• Or install other versions of docker

$ yum list docker-engine.x86_64  --showduplicates |sort -r

docker-engine.x86_64  1.13.0-1.el7                               docker-main
docker-engine.x86_64  1.12.5-1.el7                               docker-main   
docker-engine.x86_64  1.12.4-1.el7                               docker-main   
docker-engine.x86_64  1.12.3-1.el7                               docker-main   

$ sudo yum -y install docker-engine-<VERSION_STRING>

• start docker

$ sudo systemctl start docker
$ sudo systemctl enable docker

• To confirm that the docker installation is running properly install a demo image

$ sudo docker run hello-world

Upgrade Docker

$ sudo yum makecache fast

$ yum list docker-engine.x86_64  --showduplicates |sort -r

docker-engine.x86_64  1.13.0-1.el7                               docker-main
docker-engine.x86_64  1.12.5-1.el7                               docker-main   
docker-engine.x86_64  1.12.4-1.el7                               docker-main   
docker-engine.x86_64  1.12.3-1.el7                               docker-main   

$ sudo yum -y install docker-engine-<VERSION_STRING>

rpm installation

• Visit https://yum.dockerproject.org/repo/main/centos/ to select the corresponding docker version software according to the operating system version number.

• Change to paththe directory where docker.rpm is saved

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

• start docker

$ sudo systemctl start docker
$ sudo systemctl enable docker

• To confirm that the docker installation is running properly install a demo image

$ sudo docker run hello-world

uninstall docker

• uninstall docker software

$ sudo yum -y remove docker-engine

• Images, containers, volumes, and configuration files will not be deleted automatically. You need to delete them manually. If you are sure you don't need them, you can execute the following commands:

$ sudo rm -rf /var/lib/docker

At the same time, various configuration files must be manually deleted

Reference documentation https://docs.docker.com/

Directory of system yum sources:
 /etc/yum.repos.d