记得卸载老版本Docker，如新环境则忽略该提示
设置yum源改为阿里镜像
修改yum配置文件
vim /etc/yum.repos.d/CentOS-Base.repo
编辑内容
注释掉所有 mirrorlist 行
取消所有的baseurl的注释，并将所有的 mirrorlist.centos.org 改为 mirrors.aliyun.com
内容如下：
[base]
name=CentOS-$releasever - Base
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os&infra=$infra
baseurl=https://mirrors.aliyun.com/centos/$releasever/os/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
#released updates
[updates]
name=CentOS-$releasever - Updates
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates&infra=$infra
baseurl=https://mirrors.aliyun.com/centos/$releasever/updates/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras&infra=$infra
baseurl=https://mirrors.aliyun.com/centos/$releasever/extras/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-$releasever - Plus
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=centosplus&infra=$infra
baseurl=https://mirrors.aliyun.com/centos/$releasever/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
安装yum工具
sudo yum install -y yum-utils
设置Docker国内镜像
$ sudo yum-config-manager --add-repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
安装Docker
sudo yum install docker-ce docker-ce-cli containerd.io docker-compose-plugin
验证Docker版本
docker -v
启动docker
docker启动命令
systemctl start docker
systemctl stop docker
systemctl status docker
docker镜像配置
登录阿里云账号（https://cr.console.aliyun.com/cn-hangzhou/instances/mirrors）
根据操作文档配置镜像文件 /etc/docker/daemon.json
