expect脚本交互操作——FIT升级FAT

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需求

脚本自动控制通过SSH自动登录到路由器，并执行相关命令进行自动升级

** shell脚本无法完成这种交互，最终选择expect脚本进行操作**

expect

expect用于自动化地执行linux环境下的命令行交互任务，例如scp、ssh之类需要用户手动输入密码然后确认的任务

安装

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sudo apt-get install expect

操作系统：ubuntu18.04

基础语法

expect的实现核心是spawn expect send set

关键字作用
spawn调用要执行的命令
expect等待命令提示信息的出现，也就是捕获用户输入提示
send发送要交互的值，替代用户手动输入内容
set设置变量值
interact执行完成后保持交互状态，把控制权交给控制台，这个时候就可以手工操作了。如果没有这一句登录完成后会退出，而不是留在远程终端上。
expect eof这个一定要加，与spawn对应表示捕获终端输出信息终止，类似于if….endif

expect脚本必须以interact或expect eof结束，执行自动化任务通常expect eof就可以

脚本第一行必须是#!/usr/bin/expect，第一行注释也不行，否则执行报错

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#!/usr/bin/expect
set timeout 5  //设置超时时间5秒
set server [lindex $argv 0]  //传入的第一个参数
set user [lindex $argv 1]
set passwd [lindex $argv 2]

spawn ssh -l $user $server   //执行ssh命令

//如果匹配到了yes/no就发送yes，接着在匹配password，发送密码
expect {
"*yes/no" { send "yes\r"; exp_continue}
"*password:" { send "$passwd\r" }
}

expect *Last login*

//执行完成后保持交互状态，把控制权交给控制台，就可以手工操作
interact
  • 执行命令的超时时间可以设置set timeout 5,默认的超时时间是10s,如果设置为-1表示永不超时

示例–FIT升级FAT

shell脚本

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#!/bin/bash

netstat=$(ping -c1 169.254.1.1 |grep transmitted |awk '{print $4}')
if [ "$netstat" -eq "0" ]; then
    echo "      ***********************************"
    echo "      * Network connection disconnected *"
    echo "      ***********************************"
    echo "Configuring a local network, IP: 169.254.1.100"
    exit 1
fi

ssh-keygen -f "$home/.ssh/known_hosts" -R "169.254.1.1"

cat > update.exp << EOF
#!/usr/bin/expect -f

#set timeout 10
spawn ssh admin@169.254.1.1

expect {
	"*yes/no" {
		send "yes\r";
		exp_continue
	}
	"*password:" {
		send "admin@huawei.com\r"
	}
}

expect {
   "<Huawei>" {
       send "system-view\r"
       send "ap-mode-switch prepare\r"
       send "ap-mode-switch check\r"
       set timeout -1
       send "ap-mode-switch tftp FatAP3010DN-V2_V200R008C10SPC500.bin 169.254.1.100\r"
   }
}

expect {
   "Y/N" {
       set timeout 10
       send "Y\r\n"
   }
}

expect eof
EOF

chmod a+x update.exp
./update.exp
rm ./update.exp

netstat=$(ping -c3 169.254.1.1 |grep transmitted |awk '{print $4}')
while [ "$netstat" -ne "0" ]
do
    echo -n "#"
    netstat=$(ping -c3 169.254.1.1 |grep transmitted |awk '{print $4}')
done

echo "Firmware upgrade succeeded"

echo ""
echo "Device restart ..."

netstat=$(ping -c3 169.254.1.1 |grep transmitted |awk '{print $4}')
while [ "$netstat" -eq "0" ]
do
    echo -n "*"
    netstat=$(ping -c3 169.254.1.1 |grep transmitted |awk '{print $4}')
done

echo "Device restart succeeded"
echo "over"
echo "over"

expect脚本

  • 处理的交互流程：
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$ssh admin@169.254.1.1
The authenticity of host '169.254.1.1 (169.254.1.1)' can't be established.
RSA key fingerprint is SHA256:ANKtrCYlGExlxhtgCoD1ZiOxflXyEsyvswS4fC5nzc8.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '169.254.1.1' (RSA) to the list of known hosts.
admin@169.254.1.1's password:

Info: Current mode: Fit (managed by the AC).
Info: You are advised to change the password to ensure security.
<Huawei>system-view
Enter system view, return user view with Ctrl+Z.
[Huawei]ap-mode-switch prepare
Info: Prepare is ok, Use ap-mode-switch command to switch to fat ap.

[Huawei]ap-mode-switch check
Info: Ap-mode-switch check ok.

[Huawei]ap-mode-switch tftp FatAP3010DN-V2_V200R008C10SPC500.bin 169.254.1.100
Info: Preparing to upgrade. Please wait a moment .............
Warning: Do Not Power-off!
......................................................................................................................................................................................................................................................................................................................
Info: Upgrade upgrade-assistant-package succeeded.

Warning: System will reboot, if you want to switch to upgrade-assistant-package.
Are you sure to execute these operations ? [Y/N]:Y
Info: system is rebooting ,please wait...
  • 实现：
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#!/usr/bin/expect -f

#set timeout 10
spawn ssh admin@169.254.1.1

expect {
    "*yes/no" {
		send "yes\r";
		exp_continue
	}
    "*password:" {
		send "admin@huawei.com\r"
	}
}

expect {
   "<Huawei>" {
       send "system-view\r"
       send "ap-mode-switch prepare\r"
       send "ap-mode-switch check\r"
       set timeout -1
       send "ap-mode-switch tftp FatAP3010DN-V2_V200R008C10SPC500.bin 169.254.1.100\r"
   }
}

expect {
   "Y/N" {
       set timeout 10
       send "Y\r\n"
   }
}

expect eof

参考

  • Shell脚本学习之expect命令