安装前准备：

更新安装源：

wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo

安装epel源

yum install epel-release

安装docker依赖包

yum install container-selinux

添加docker安装源

yum-config-manager --add-repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
yum repolist
sudo sed -i ‘s+download.docker.com+mirrors.aliyun.com/docker-ce+’ /etc/yum.repos.d/docker-ce.repo
yum makecache fast

yum list docker-ce --showduplicates | sort -r

安装docker-ce

yum install docker-ce

启动docker-ce并查询运行状态

systemctl start docker
systemctl status docker

用ifconfig查看网络连接，多了一个docker0的网络接口

docker安装并且启动成功