如何在 python 中使用 netmiko 在多個 cisco 設備上執行 ssh

Question

我正在嘗試為多個設備運行下面的腳本，它僅適用於根據以下腳本的最后一個設備。

請您驗證以下腳本，因為我需要使用 for 循環語句執行兩個設備輸出。

from netmiko import ConnectHandler 
from getpass import getpass

password= getpass()

RTR_01 = {

         'device_type': 'cisco_ios',
         'host': '10.10.10.10',
         'username': 'admin',
         'password': password,
}

RTR_02 = { 'device_type': 'cisco_ios', 
           'host': '10.10.10.11', 
           'username': 'admin', 
           'password': password, }

device_list = [RTR_01,RTR_02] 

for device in device_list: print('Connecting to the device :' + device ['host']) 

net_connect = ConnectHandler(**device)

output = net_connect.send_command('show ip interface brief')
print(output)
output = net_connect.send_command('show version')
print(output)

Answer 1

我現在如何 100% 正確工作。 我曾嘗試過使用適當的縮進的net_connect.disconnect() ，但它不起作用，因為一旦退出循環的縮進，它就會自動退出。 問題雖然很愚蠢，但我仍然連接到實際設備並收到一個我忽略的錯誤，抱怨無法創建/var/home/myusername/.ssh

我需要做的就是在循環的最后發出以下命令：

net_connect.write_channel('exit\\n')

諸如愚蠢的錯誤和浪費了這么多時間，但教訓是寶貴的！ 也許它可以幫助這里的其他人。

Answer 2

你需要這些行在 for 循環中縮進

net_connect = ConnectHandler(**device)

output = net_connect.send_command('show ip interface brief')
print(output)
output = net_connect.send_command('show version')
print(output)

您的代碼應如下所示：

from getpass import getpass

from netmiko import ConnectHandler

password = getpass()

RTR_01 = {
    "device_type": "cisco_ios",
    "host": "10.10.10.10",
    "username": "admin",
    "password": password,
}

RTR_02 = {
    "device_type": "cisco_ios",
    "host": "10.10.10.11",
    "username": "admin",
    "password": password,
}

device_list = [RTR_01, RTR_02]

for device in device_list:
    print("Connecting to the device :" + device["host"])

    net_connect = ConnectHandler(**device)

    output = net_connect.send_command("show ip interface brief")
    print(output)
    output = net_connect.send_command("show version")
    print(output)

    net_connect.disconnect() # to clear the vty line when done

這是你的代碼的更好版本，它做同樣的事情：

from getpass import getpass

from netmiko import ConnectHandler

password = getpass()

ipaddrs = ["10.10.10.10", "10.10.10.11"]

# A list comprehension
devices = [
    {
        "device_type": "cisco_ios",
        "host": ip,
        "username": "admin",
        "password": password,
    }
    for ip in ipaddrs
]

for device in devices:
    print(f'Connecting to the device: {device["host"]}')

    with ConnectHandler(**device) as net_connect:  # Using Context Manager
        intf_brief = net_connect.send_command(
            "show ip interface brief"
        )  # Inside the connection
        facts = net_connect.send_command("show version")  # Inside the connection

        # Notice here I didn't call the `net_connect.disconnect()`
        # because the `with` statement automatically disconnects the session.

    # On this indentation level (4 spaces), the connection is terminated
    print(intf_brief)
    print(facts)

輸出（ intf_brief和facts ）在連接外打印，因為不再需要會話來打印任何收集的值。