本机node1
实现本机的免密码登录:
# ssh-keygen -t dsa -P ' ' -f ~/.ssh/id_dsa
# cat ~/.ssh/id_dsa.pub >> ~/.ssh/authorized_keys
将node的公钥复制到node4的/opt/中
# scp ./id_dsa.pub root@node4:/opt
node4中也要执行# ssh-keygen -t dsa -P ' ' -f ~/.ssh/id_dsa 目的是为了生成 .ssh文件夹
转到node4，执行cat /opt/id_dsa.pub >> ~/.ssh/authorized_keys