每次安装都要去看官方文档，比较烦。所以把官网的搬过来。官网链接：https://docs.docker.com/install/linux/docker-ce/centos/

#卸载已有的Docker
sudo yum remove docker \
                  docker-client \
                  docker-client-latest \
                  docker-common \
                  docker-latest \
                  docker-latest-logrotate \
                  docker-logrotate \
                  docker-engine

#依赖安装

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

#增加YUM源

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

#启用YUM源
sudo yum-config-manager --enable docker-ce-nightly

#安装
sudo yum install docker-ce docker-ce-cli containerd.io

#启用服务
sudo systemctl start docker

#测试
sudo docker run hello-world