HNT: #3 - Python - Netmiko Scripts to Automate Tasks in Cisco Devices

In this section i will introduce some improovment of this Script.

As you see now we have separate file and new argv structure to run the script:

python@python:~$ ls -l

-* command3.py (Main Script with some improvements)

-* credential_tools.py (Script witch gets User and Password with Prompt)

-* devices.json ( Here we have list of the devices in Json format

-* commands.txt (Here we paste all Needed Commands to configure on Devices)

### command3.py

python@python:~$ cat command3.py

#!/usr/bin/python

import netmiko

import json

import credential_tools

import sys

import signal

# Avoid and ignore some Errors

signal.signal(signal.SIGPIPE, signal.SIG_DFL) # IOError: Broken Pipe

signal.signal(signal.SIGINT, signal.SIG_DFL) # KeyboardInterrupt: Ctrl-C

# Usage of the script-> : Usage: [Script].py [Commands].txt [Devices].json

if len(sys.argv) < 3:

print("Error...")

print("Usage: [Script].py [Commands].txt [Devices].json")

exit()

# Bypass some esceptions and document it to avoid Script failure.

netmiko_exceptions = (netmiko.ssh_exception.NetMikoTimeoutException,

netmiko.ssh_exception.NetMikoAuthenticationException)

# Get User Credentials using external module with is imported as "credential_tools"

username, password = credential_tools.get_credentials()

# Read Commands from file:

with open(sys.argv[1]) as cmd_file:

commands = cmd_file.readlines()

# Read Device list from File:

with open(sys.argv[2]) as dev_file:

devices = json.load(dev_file)

# Main Netmiko connection Script

for device in devices:

device["username"] = username

device["password"] = password

try:

print("-"*80)

connection = netmiko.ConnectHandler(**device)

# Define and get hostname from Netmiko processes:

hostname = connection.base_prompt

print("Selected Device: " + hostname)

print("***Connecting to Device: " + device["ip"] + "\n")

for command in commands:

print("## Output of " + command)

print(connection.send_command(command) + "\n")

#Disconnect and close SSH session

print("***Disconnecting From Device...")

print("-"*80)

connection.disconnect()

# If Exception present bypass...

except netmiko_exceptions as e:

print("Failed to:", device["ip"], e)

### credential_tools.py

python@python:~$ cat credential_tools.py

from getpass import getpass

def get_input(prompt=""):

try:

line = raw_input(prompt)

except NameError:

line = input(prompt)

return line

def get_credentials():

"""Prompts for, and returns, a username and password."""

username = get_input("Enter Username: ")

password = None

while not password:

password = getpass()

password_verify = getpass("Retype Your Password: ")

if password != password_verify:

print("Password do not match. Try again! ")

password = None

return username, password

# devices.json

python@python:~$ cat devices.json

[

{

"ip": "10.0.10.105",

"device_type": "cisco_ios"

{

"ip": "10.0.10.106",

"device_type": "cisco_ios"

{

"ip": "10.0.10.107",

"device_type": "cisco_ios"

{

"ip": "10.0.10.108",

"device_type": "cisco_ios"

}

]

### commands.txt

python@python:~$ cat commands.txt

show clock

show ver | in time

show ip interface brief | exc unas

show arp

show ip route connected | beg Gate

### Run the Script...
Result:
python@python:~$ ./command3.py commands.txt devices.json
Enter Username: admin
Password: *****
Retype Your Password: *****
--------------------------------------------------------------------------------
Selected Device: XZSNR0801
***Connecting to Device: 10.0.10.105

## Output of show clock

*20:20:43.917 UTC Sun Mar 31 2019

## Output of show ver | in time

XZSNR0801 uptime is 3 days, 2 hours, 3 minutes

## Output of show ip interface brief | exc unas

Interface IP-Address OK? Method Status Protocol
GigabitEthernet1/0 10.0.10.105 YES manual up up

## Output of show arp

Protocol Address Age (min) Hardware Addr Type Interface
Internet 10.0.10.6 0 94db.c903.c580 ARPA GigabitEthernet1/0
Internet 10.0.10.29 0 94db.c903.c580 ARPA GigabitEthernet1/0
Internet 10.0.10.105 - ca00.14d4.001c ARPA GigabitEthernet1/0
Internet 10.0.10.106 84 ca06.14d4.001c ARPA GigabitEthernet1/0
Internet 10.0.10.107 83 ca07.1920.001c ARPA GigabitEthernet1/0
Internet 10.0.10.254 0 e055.3d4d.8b28 ARPA GigabitEthernet1/0

## Output of show ip route connected | beg Gate

Gateway of last resort is not set

10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C 10.0.10.0/24 is directly connected, GigabitEthernet1/0
L 10.0.10.105/32 is directly connected, GigabitEthernet1/0

***Disconnecting From Device...
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Selected Device: XZSNR0802
***Connecting to Device: 10.0.10.106

## Output of show clock

*20:21:23.825 UTC Sun Mar 31 2019

## Output of show ver | in time

XZSNR0802 uptime is 3 days, 1 hour, 51 minutes

## Output of show ip interface brief | exc unas

Interface IP-Address OK? Method Status Protocol
GigabitEthernet1/0 10.0.10.106 YES manual up up

## Output of show arp

Protocol Address Age (min) Hardware Addr Type Interface
Internet 10.0.10.6 0 94db.c903.c580 ARPA GigabitEthernet1/0
Internet 10.0.10.29 0 94db.c903.c580 ARPA GigabitEthernet1/0
Internet 10.0.10.105 84 ca00.14d4.001c ARPA GigabitEthernet1/0
Internet 10.0.10.106 - ca06.14d4.001c ARPA GigabitEthernet1/0

## Output of show ip route connected | beg Gate

Gateway of last resort is not set

10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C 10.0.10.0/24 is directly connected, GigabitEthernet1/0
L 10.0.10.106/32 is directly connected, GigabitEthernet1/0

***Disconnecting From Device...
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
('Failed to:', u'10.0.10.107', NetMikoAuthenticationException(u'Authentication failure: unable to connect cisco_ios 10.0.10.107:22\nAuthentication failed.',))
--------------------------------------------------------------------------------
('Failed to:', u'10.0.10.108', NetMikoTimeoutException(u'Connection to device timed-out: cisco_ios 10.0.10.108:22',))

31 March, 2019

#3 - Python - Netmiko Scripts to Automate Tasks in Cisco Devices