多台linux无密码访问之方法一
一：实验环境：
1.四台SLES 11 SP2 X86_64 最小化安装
2.其中主机名和IP对应关系如下
manager 192.168.78.11
node1 192.168.78.12
node2 192.168.78.13
node3 192.168.78.14
二：配置过程如下：
1.在manager的/etc/hosts下添加内容如下
192.168.78.11 manager
192.168.78.12 node1
192.168.78.13 node2
192.168.78.14 node3
2.生成无私钥密码的密钥对
manager:~ # ssh-keygen
Generating public/private rsa key pair.
Enter file in which to save the key(/root/.ssh/id_rsa): //直接Enter键
Created directory '/root/.ssh'.
Enter passphrase (empty for no passphrase): //直接Enter键
Enter same passphrase again: //直接Enter键
Your identification has been saved in/root/.ssh/id_rsa.
Your public key has been saved in/root/.ssh/id_rsa.pub.
The key fingerprint is:
c2:e9:a3:48:a5:57:3c:64:a8:b6:17:71:ff:93:4d:2froot@manager
The key's randomart image is:
+--[ RSA 2048]----+
| |
| . |
| o + |
| .B o |
| oo B S . |
| . + + o . + . |
| +o o + E . |
| . + . . . . |
| .. |
+-----------------+
manager:~ #
3.生成认证文件authorized_keys并设置相应权限
manager:~ # cd .ssh/
manager:~/.ssh # ls
id_rsa id_rsa.pub
manager:~/.ssh # cp id_rsa.pub authorized_keys
manager:~/.ssh # chmod 600 authorized_keys
manager:~/.ssh # ls -l
total 12
-rw------- 1 root root 394 Dec 11 05:13 authorized_keys
-rw------- 1 root root 1675 Dec 11 05:12id_rsa
-rw-r--r-- 1 root root 394 Dec 11 05:12 id_rsa.pub
manager:~/.ssh #
4.复制/root/.ssh目录到node1,node2,node3的root目录下,复制可通过创建一个脚本，比如名为rep.sh,内容如下,并执行此脚本
#!/bin/bash
for i in `seq 1 3` //1和3根据实际情况调整
do
expect <<EOF
set timeout -1
spawn scp -r /root/.ssh node$i:/root/
expect "(yes/no)"
send "yes\r"
expect "Password:"
send "111111\r"
expect eof
EOF
done
注：第一次是基于口令的认证，所以要输入密码
5.复制/etc/hosts文件到node1,node2,node3的/etc目录下
manager:~ # for i in `seq 1 3`; do scp /etc/hosts node$i:/etc/ ; done
6.ssh访问本机（以便添加manager到.ssh/known_hosts文件下）
manager:~ # ssh manager
The authenticity of host 'manager(192.168.78.11)' can't be established.
RSA key fingerprint ise6:74:87:2c:5e:71:30:c8:ae:9d:87:d4:54:05:d0:22.
Are you sure you want to continueconnecting (yes/no)? yes
Warning: Permanently added'manager,192.168.78.11' (RSA) to the list of known hosts.
Last login: Thu Dec 11 05:06:27 2014 from192.168.78.1
manager:~ #
7.复制.ssh/known_hosts文件到node1,node2,node3的/root/.ssh/目录下
manager:~ # for i in `seq 1 3`; do scp /root/.ssh/known_hosts node$i:/root/.ssh/ ; done
至此配置完成
三：检验配置是否成功
1.随便选择一台机器比如node3,分别访问manager,node1,node2
node3:~ # ssh manager
Last login: Thu Dec 11 05:20:52 2014 frommanager //无密码登录manager成功
manager:~ # exit //退出到manager的连接
logout
Connection to manager closed.
node3:~ # ssh node1
Last login: Mon Sep 29 23:24:13 2014
linux-x4xj:~ # exit
logout
Connection to node1 closed.
node3:~ # ssh node2
Last login: Mon Sep 29 23:24:28 2014
linux-hmae:~ # exit
logout
Connection to node2 closed.
node3:~ #
由以上可知配置成功，node1,node2节点测试同上
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注意事项：
1.如果要重装某个节点比如重装node2，要按顺序执行下面4步
◆在重装node2之前需要先备份/etc/下的ssh目录
◆重装完成后，首先把/etc目录下的ssh目录替换为备份的ssh目录并重启ssh服务
◆然后从manager,node1或node3上复制.ssh目录到node2的/root目录下
◆最后复制hosts文件到node2的/etc目录下
2.普通用户的操作
◆生成无私钥密码的密钥对（操作同root）
◆生成认证文件authorized_keys并设置相应权限（操作同root）
◆ssh访问本机（以便添加manager到.ssh/known_hosts文件下）
◆创建一个脚本，比如名为test.sh,内容如下,并执行此脚本
#!/bin/bash
for i in `seq 1 3` //1和3根据实际情况调整
do
expect <<EOF
set timeout -1
spawn ssh node$i date
expect "(yes/no)"
send "yes\r"
expect eof
EOF
done
至此普通用户配置完毕
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本文出自 “永不止步” 博客，谢绝转载！