如何使用pexcept发送本地和远程命令？

Question

我有一个简单的类，允许我发送大量本地CLI命令。允许我测试某些命令行函数。这种机制运作得很好，但还需要扩展。我很难理解如何改变这种机制来处理本地或远程命令。

from pexpect import *
class Expect( ):
    def Do( self, cmd, program: list = [], timeout = 20 ):
        result = run( cmd, events=program, timeout=timeout).decode() 
        return result

cmd  = 'login'
prog = [('username \\(.+\\):', 'yourUN\n'), ('password:', 'yourPW\n')]
res  = Expect().Do( cmd, prog )    # Returns everything
print( 'res: ' + res )
# use results to verify functionality

返回如下内容：

username (root):yourUN
password:*****
Logged in user yourUN

我目前有超过1250个测试，运行了大约5000个cli本地命令。唯一的问题是，我需要这个类来支持本地命令和远程SSH命令。

我已经设置我的测试机器允许远程SSH没有用户SSH登录。

Answer 1

如果我理解这个问题，并且基于我的测试，您将需要两个函数或方法。

1.第一个函数使用运行本地命令。还可以使用第一个函数运行ssh命令，但前提是known_hosts文件中存在IP地址：

pexpect.run("ssh yourUN@192.168.x.x 'whoami'")

否则，您将遇到一个"The authenticity of host '192.168.x.x (192.168.x.x)' can't be established."错误。

为了避免这个错误，我建议使用Paramiko的ssh命令使用第二个函数。

以下是完整的代码：

注意到在Linux5.14.16上使用Python3.9进行了测试。远程机器是Ubuntu8.04。

from getpass import getpass

import paramiko
import pexpect


def run_cli_commands(list_of_commands, password=None):
    for c in list_of_commands:
        print("Command:", c)
        command_output, exitstatus = pexpect.run(
            c,
            events={"(?i)password": password if password is not None else getpass()},
            withexitstatus=True)
        print("Output:\n", command_output.decode())


def run_ssh_commands(list_of_commands, ip_address, username, password):
    ssh = paramiko.SSHClient()
    ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
    ssh.connect(ip_address, username=username, password=password)
    for c in list_of_commands:
        print("Command:", c)
        stdin, stdout, stderr = ssh.exec_command(c)
        print("Output:\n", stdout.read().decode())


run_cli_commands(["which ssh",
                  "systemctl status ssh",
                  "systemctl start ssh",
                  "systemctl status ssh", ], password="**********")
run_ssh_commands(["whoami",
                  "date", ], "192.168.x.x", "yourUN", "**********")
run_cli_commands(["systemctl stop ssh", ], password="**********")
print("Script complete. Have a nice day.")

输出：

Local command: which ssh
Output:
 /usr/bin/ssh

Local command: systemctl status ssh
Output:
 ○ ssh.service - OpenBSD Secure Shell server
     Loaded: loaded (/lib/systemd/system/ssh.service; disabled; vendor preset: disabled)
     Active: inactive (dead)
       Docs: man:sshd(8)
             man:sshd_config(5)

Local command: systemctl start ssh
Output:
 
Local command: systemctl status ssh
Output:
 ● ssh.service - OpenBSD Secure Shell server
     Loaded: loaded (/lib/systemd/system/ssh.service; disabled; vendor preset: disabled)
     Active: active (running) since Thu 2021-12-09 23:13:05 EST; 174ms ago
       Docs: man:sshd(8)
             man:sshd_config(5)
    Process: 4565 ExecStartPre=/usr/sbin/sshd -t (code=exited, status=0/SUCCESS)
   Main PID: 4566 (sshd)
      Tasks: 1 (limit: 2275)
     Memory: 2.3M
        CPU: 18ms
     CGroup: /system.slice/ssh.service
             └─4566 "sshd: /usr/sbin/sshd -D [listener] 0 of 10-100 startups"

SSH command: whoami
Output:
 yourUN

SSH command: date
Output:
 Thu Dec  9 23:13:04 EST 2021

Local command: systemctl stop ssh
Output:
 
Script complete. Have a nice day.