配置主机之间无密码登录每台机器都按照如下操作
ssh-keygen -t rsa #一路回车,不输入密码把本地的 ssh 公钥文件安装到远程主机对应的账户
ssh-copy-id -i .ssh/id_rsa.pub master-1 ssh-copy-id -i .ssh/id_rsa.pub node-1 ssh-copy-id -i .ssh/id_rsa.pub node-2