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9.21任务

程序员文章站 2022-05-07 10:53:13
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20.27 分发系统介绍

场景：业务逐渐增大，网站的app的后端编程语言是php，想要运行php要配置一个LNMP、LAMP的环境，但是平常业务在不断的迭代，如果服务器增多，那我们就需要的一个分发系统，用来把新的代码传递到各个服务器上去。

这里讲解的expect软件就是一个上线的系统。

首先要准备一台模板的机器，这里是最新的代码，然后需要上线的机器的对应的ip和密码都需要知道，然后就可以推送最新的代码给所有的机器。


20.28 expect脚本远程登录

之前安装过的包有一个叫mkpasswd的命令，安装这个的时候安装的包就是expect。

我们第一个实例就是自动登录远程某一天机器，并执行命令。

脚本如下：

#!/usr/bin/expect

set host "192.168.133.132"
set passwd "123456"
spawn ssh [email protected]$host
expect {
    "yes/no" { send "yes\r"; exp_continue}
    "password:" { send "$passwd\r" }
}
interact

设置变量要使用set命令，spawn关键字后面跟的就是shell命令，expect就是传递消息。

引号内是截取的信号字段，后面花括号内是执行的命令。

exp_continue是继续执行expect，interact是结束。

[email protected]:~/shell_script# ./expect1.sh 
spawn ssh [email protected]
The authenticity of host '192.168.0.109 (192.168.0.109)' can't be established.
ECDSA key fingerprint is SHA256:RGujPvieJX8G0MYV7PLypBodAkZ+M5RYrxMnFJeltNE.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.0.109' (ECDSA) to the list of known hosts.
[email protected]'s password: 
Welcome to Ubuntu 16.04.5 LTS (GNU/Linux 4.15.0-34-generic x86_64)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/advantage

39 packages can be updated.
0 updates are security updates.

New release '18.04.1 LTS' available.
Run 'do-release-upgrade' to upgrade to it.

Last login: Wed Sep 26 23:10:28 2018 from 192.168.0.109

执行完脚本之后就会进入我们的192.168.0.109主机。

这里需要注意的一点是expect后的左花括号要写在一行。


20.29 expect脚本远程执行命令

脚本如下，过程就是登录以后执行命令然后退出。

#!/usr/bin/expect
set user "root"
set passwd "123456"
spawn ssh [email protected]

expect {
"yes/no" { send "yes\r"; exp_continue}
"password:" { send "$passwd\r" }
}
expect "]*"
send "touch /tmp/12.txt\r"
expect "]*"
send "echo 1212 > /tmp/12.txt\r"
expect "]*"
send "exit\r"

这里要按照自己的PS1的设置去更改。

结果如下

[email protected]:~/shell_script# chmod 700 expect2.sh 
[email protected]:~/shell_script# ./expect2.sh 
spawn ssh [email protected]
[email protected]'s password: 
Welcome to Ubuntu 16.04.5 LTS (GNU/Linux 4.15.0-34-generic x86_64)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/advantage

39 packages can be updated.
0 updates are security updates.

New release '18.04.1 LTS' available.
Run 'do-release-upgrade' to upgrade to it.

Last login: Wed Sep 26 23:11:28 2018 from 192.168.0.109
[email protected]:~$ touch /tmp/12.txt
[email protected]:~$ echo 1212 > /[email protected]:~/shell_script# ./expect1.sh 
spawn ssh [email protected]
[email protected]'s password: 
Welcome to Ubuntu 16.04.5 LTS (GNU/Linux 4.15.0-34-generic x86_64)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/advantage

39 packages can be updated.
0 updates are security updates.

New release '18.04.1 LTS' available.
Run 'do-release-upgrade' to upgrade to it.

Last login: Thu Sep 27 11:13:51 2018 from 192.168.0.109
[email protected]:~$ ls /tmp/12.txt -l
-rw-rw-r-- 1 lhy lhy 5 Sep 27 11:13 /tmp/12.txt
[email protected]:~$ cat /tmp/12.txt 
1212

最后没有显示完整，应该与脚本执行速度过快而带来的影响。这里我测试的结果就是最后一定要在脚本的最后一行协商interact。

当然不需要留下交互的脚本也可以使用expect eof来结束。


20.30 expect脚本传递参数

脚本如下

#!/usr/bin/expect

set user [lindex $argv 0]
set host [lindex $argv 1]
set passwd "123456"
set cm [lindex $argv 2]
spawn ssh [email protected]$host

expect {
"yes/no" { send "yes\r"}
"password:" { send "$passwd\r" }
}
expect "]*"
send "$cm\r"
expect "]*"
send "exit\r"

传参规范就是方括号内写的是内置变量lindex+参数数组。

[email protected]:~/shell_script# ./expect3.sh lhy 192.168.0.109 "ll /tmp"
spawn ssh [email protected]
[email protected]'s password: 
Welcome to Ubuntu 16.04.5 LTS (GNU/Linux 4.15.0-34-generic x86_64)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/advantage

39 packages can be updated.
0 updates are security updates.

New release '18.04.1 LTS' available.
Run 'do-release-upgrade' to upgrade to it.

Last login: Thu Sep 27 11:56:59 2018 from 192.168.0.109
[email protected]:~$ ll /tmp
total 620
drwxrwxrwt 10 root root   4096 Sep 27 12:03 ./
drwxr-xr-x 25 root root   4096 Sep 17 01:06 ../
-rw-rw-r--  1 lhy  lhy       5 Sep 27 11:56 12.txt
drwxrwxrwt  2 root root   4096 Sep 16 15:06 .font-unix/
drwxrwxrwt  2 root root   4096 Sep 16 15:06 .ICE-unix/
drwx------  3 root root   4096 Sep 16 15:06 systemd-private-10e54c0f924f4fa5bb0916a17c4ee96e-colord.service-6ienvA/
drwx------  3 root root   4096 Sep 16 15:06 systemd-private-10e54c0f924f4fa5bb0916a17c4ee96e-rtkit-daemon.service-J5oPaN/
drwx------  3 root root   4096 Sep 16 15:06 systemd-private-10e54c0f924f4fa5bb0916a17c4ee96e-systemd-timesyncd.service-iK7nm1/
-rw-r--r--  1 root root    253 Sep 25 15:17 test.log
drwxrwxrwt  2 root root   4096 Sep 16 15:06 .Test-unix/
-rw-------  1 root root     12 Sep 18 11:17 tmp0SscPz
-rw-rw----  1 root root      0 Sep 18 11:17 tmp2dfC8z
-rw-------  1 root root     24 Sep 18 11:17 tmp2xgfN_
-rw-rw----  1 root root    377 Sep 18 11:17 tmp70bCDG
-rw-------  1 root root     45 Sep 18 11:17 tmp7yVz5Z
-rw-------  1 root root 525838 Sep 18 11:51 tmpaddon
-rw-------  1 root root     12 Sep 18 11:17 tmpaHgRZn
-rw-------  1 root root     12 Sep 18 11:17 tmpB4sAb4
-rw-rw----  1 root root      0 Sep 18 11:17 tmpEA1aPa
-rw-rw----  1 root root     41 Sep 18 11:17 tmpK1ZTYd
-rw-rw----  1 root root     15 Sep 18 11:17 tmpLeVM2c
-rw-------  1 root root     90 Sep 18 11:17 tmpMZC8xK
-rw-rw----  1 root root     48 Sep 18 11:17 tmpoCCFCH
-rw-------  1 root root      0 Sep 18 11:17 tmppJTX02
-rw-rw----  1 root root      0 Sep 18 11:17 tmpRkryP2
-rw-rw----  1 root root     10 Sep 18 11:17 tmprRQNYC
-rw-------  1 root root    478 Sep 18 11:17 tmpTshdUn
-rw-rw----  1 root root      0 Sep 18 11:17 tmpwsFmBe
-rw-------  1 root root    116 Sep 18 11:17 tmpzjSgya
-r--r--r--  1 root root     11 Sep 16 15:06 .X0-lock
drwxrwxrwt  2 root root   4096 Sep 16 15:06 .X11-unix/
drwxrwxrwt  2 root root   4096 Sep 16 15:06 .XIM-unix/
[email protected]:~$ exit
logout
Connection to 192.168.0.109 closed.

执行的命令最好用双引号括起来，多条命令用分号分隔。

expect有一个默认超时时间，超时之后expect的任务都会结束。

所以expect脚本要考虑好超时时间，当然也是可以用set timeout 来设置自定义的超时时间。

转载于:https://my.oschina.net/u/3866688/blog/2209361

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