shell脚本实现ssh登陆

• ssky-keygen + ssh-copy-id 无密码登陆远程LINUX主机

使用下例中ssky-keygen和ssh-copy-id，仅需通过3个步骤的简单设置而无需输入密码就能登录远程Linux主机。
ssh-keygen 创建公钥和密钥。
ssh-copy-id 把本地主机的公钥复制到远程主机的authorized_keys文件上。
ssh-copy-id 也会给远程主机的用户主目录（home）和~/.ssh, 和~/.ssh/authorized_keys设置合适的权限
步骤1: 用 ssh-key-gen 在本地主机上创建公钥和密钥
ligh@local-host$ ssh-keygen -t  rsa 【生成本地公钥】
Enter file in which to save the key (/home/jsmith/.ssh/id_rsa):[Enter key]
Enter passphrase (empty for no passphrase): [Press enter key]
Enter same passphrase again: [Pess enter key]
Your identification has been saved in /home/jsmith/.ssh/id_rsa.
Your public key has been saved in /home/jsmith/.ssh/id_rsa.pub.
The key fingerprint is: 33:b3:fe:af:95:95:18:11:31:d5:de:96:2f:f2:35:f9
ligh@local-host
步骤2: 用 ssh-copy-id 把公钥复制到远程主机上
ligh@local-host$ ssh-copy-id -i ~/.ssh/id_rsa.pub  root@192.168.0.3
ligh@remote-host‘s password:
Now try logging into the machine, with ―ssh ?remote-host‘‖, and check in:
.ssh/authorized_keys to make sure we haven‘t added extra keys that you weren‘t expecting.
[注: ssh-copy-id 把密钥追加到远程主机的 .ssh/authorized_key 上.]
步骤3: 直接登录远程主机
ligh@local-host$ ssh remote-host
Last login: Sun Nov 16 17:22:33 2008 from 192.168.1.2
[注: SSH 不会询问密码.]

• 脚本实现

auto_ssh_copy_id () 
{
expect -c "set timeout -1;
spawn ssh-copy-id -i 【公钥存放路径】  $2;
expect {
*(yes/no)* {send -- yes\r;exp_continue;}
*assword:* {send -- $1\r;exp_continue;}
eof        {exit 0;}
}";
}  

auto_ssh_copy_id  $password $host
ssh $user@$host

exit 0

• ssh-copy-id:/usr/bin/ssh-copy-id: ERROR: No identities found

内网有两台机子需要配置，做 ssh 时，想到用那个 ssh-copy-id 可以大大简化公钥分配过程

$ ssh-copy-id remote-machine

公钥，私钥已经生成，执行上述命令完毕出现如下错误：

/usr/bin/ssh-copy-id: ERROR: No identities found

发现缺少公钥路径，通过 -i 加上即可

另附参考链接
http://blog.sina.com.cn/s/blog_722532880101dyuh.html