最近有时间在研究Hadoop，想把环境搭建起来，开始就遇到一个头疼的问题，在Ubuntu 环境下用ssh服务连接loaclhost，搭建了好长时间才弄好，现在整理出来供搭建参考，现在网上有很多方法实现了master到slave实现的ssh无密码登陆，这里面就不做介绍了。废话不多说，步骤有下面几步：
步骤
1.创建密钥
~/.ssh$ ssh-keygen -t rsa Generating public/private rsa key pair. Enter passphrase (empty for no passphrase): (忽略) Enter same passphrase again: (忽略) Your identification has been saved in /.ssh/id_rsa. Your public key has been saved in /.ssh/id_rsa.pub.
2.添加公密到信任列表
~/.ssh$ cat 192.168.1.101 >> authorized_keys
~/.ssh$
3.启动ssh-agent (以前没有做过的步骤)
如果ssh localhost返回这样的提示
Agent admitted failure to sign using the key
ps -aux|grep agent查看有无ssh-agent有无运行，若没有
~/.ssh$ ssh-agent
4.添加id_rsa到ssh-agent
~/.ssh$ ssh-add id_rsa如果提示： “Could not open a connection to your authentication agent” 执行：ssh-agent bash 5.修改目录权限
sudo chmod 600 ~/.ssh/id_rsa sudo chmod 600 ~/.ssh/id_rsa.pubsudo chmod 644 ~/.ssh/known_hosts sudo chmod 755 ~/.ssh 6.登陆测试~/.ssh$ ssh localhost