执行 rke up 安装集群

报错如下：

WARN[0000] Failed to set up SSH tunneling for host [172.20.101.167]: 
Can't retrieve Docker Info: error during connect: Get http://%2Fvar%2Frun%2Fdocker.sock/v1.24/info: Unable to access the Docker socket (/var/run/docker.sock). 
Please check if the configured user can execute `docker ps` on the node, and if the SSH server version is at least version 6.7 or higher. 
If you are using RedHat/CentOS, you can't use the user `root`. 
Please refer to the documentation for more instructions. Error: ssh: rejected: administratively prohibited (open failed) 

报错内容提示

大致意思说：
1：Centos 系统，不能用root 执行docker 命令；
2：Sshd 服务版本不能低于 6.7；

解决办法：

创建用户并且添加到docker组

groupadd docker
useradd rancher -G docker
echo "123456" | passwd --stdin rancher

或者将现有的一个账户加入到docke组；

usermod ptmind -G docker 

注意修改：

nodes:
  - address: 172.20.101.157 #集群节点的地址

    user: ptmind              #使用哪个用户执行安装命令   <=== 修改用户