1) 卸载旧版本docker
sudo yum remove docker \                  docker-client \                  docker-client-latest \                  docker-common \                  docker-latest \                  docker-latest-logrotate \                  docker-logrotate \                  docker-selinux \                  docker-engine-selinux \                  docker-engine
	2) 下载docker-ce的repo
curl https://download.docker.com/linux/centos/docker-ce.repo -o /etc/yum.repos.d/docker-ce.repo
	3) 安装docker依赖
yum install https://download.docker.com/linux/fedora/30/x86_64/stable/Packages/containerd.io-1.2.6-3.3.fc30.x86_64.rpm
	4) 安装docker-ce
yum install docker-ce
	5) 启动docker并添加自启动
systemctl start dockersystemctl enable docker
	7) 查看版本信息
docker version
	8) 拉取镜像,可以去镜像仓库找一个存在的镜像测试,这里是有hello-world
	sudo docker pull hello-world
	常用镜像地址:
	网易:https://c.163yun.com
	阿里云:https://cr.console.aliyun.com/
	Docker Hub: https://hub.docker.com/
	
	
	
		客户端和服务端版本信息
	
 
	
	9) 运行镜像
sudo docker pull hello-world