I want to run precheck commands, reload the device, wait for it to come back up, then reconnect and rerun the same commands. However, after the reload, I get the following error message when it's time to run the same commands again.
Notes: input.txt: contains the IPs of the devices to reboot. reload_cmds.txt: contains the list of commands sectioned per layer.
<...commands output cut for brevity...>
Would you like to proceed with reload?[Type yes or no]: yes
========= Saving configuration =========
write mem
Building configuration...
Compressed configuration from 3524 bytes to 1809 bytes[OK]
SW1#
========= Reloading the switch =========
Reload scheduled in 1 minute by admin on vty1 (192.168.1.51)
Proceed with reload? [confirm]
Disconnected
Waiting 60 seconds
========= Pinging 10.10.50.121 every 60 secs =========
10.10.50.121 is unreachable
========= Pinging 10.10.50.121 every 60 secs =========
10.10.50.121 is unreachable
========= Pinging 10.10.50.121 every 60 secs =========
10.10.50.121 is unreachable
========= Pinging 10.10.50.121 every 60 secs =========
10.10.50.121 is unreachable
========= Pinging 10.10.50.121 every 60 secs =========
10.10.50.121 is unreachable
========= Pinging 10.10.50.121 every 60 secs =========
10.10.50.121 is unreachable
========= Pinging 10.10.50.121 every 60 secs =========
10.10.50.121 is unreachable
========= Pinging 10.10.50.121 every 60 secs =========
10.10.50.121 is unreachable
========= Pinging 10.10.50.121 every 60 secs =========
10.10.50.121 is back online
############### Post-Verification ###############
Reconnected
{'device_type': 'cisco_ios', 'ip': '10.10.50.121', 'username': 'admin', 'password': 'admin'}
<netmiko.cisco.cisco_ios.CiscoIosSSH object at 0x1095fb400>
#################### Layer 1 ###################
Traceback (most recent call last):
File "/myscripts/reload.py", line 177, in <module>
ping()
File "/myscripts/reload.py", line 123, in ping
ping()
File "/myscripts/reload.py", line 123, in ping
ping()
File "/myscripts/reload.py", line 123, in ping
ping()
[Previous line repeated 5 more times]
File "/myscripts/reload.py", line 133, in ping
layer_1_check()
File "/myscripts/reload.py", line 32, in layer_1_check
layer1_output = ssh_connect.send_command(command)
File "/usr/local/lib/python3.9/site-packages/netmiko/utilities.py", line 500, in wrapper_decorator
return func(self, *args, **kwargs)
File "/usr/local/lib/python3.9/site-packages/netmiko/base_connection.py", line 1475, in send_command
prompt = self.find_prompt(delay_factor=delay_factor)
File "/usr/local/lib/python3.9/site-packages/netmiko/base_connection.py", line 1178, in find_prompt
self.clear_buffer()
File "/usr/local/lib/python3.9/site-packages/netmiko/base_connection.py", line 1216, in clear_buffer
data = self.read_channel()
File "/usr/local/lib/python3.9/site-packages/netmiko/base_connection.py", line 526, in read_channel
output = self._read_channel()
File "/usr/local/lib/python3.9/site-packages/netmiko/base_connection.py", line 500, in _read_channel
if self.remote_conn.recv_ready():
AttributeError: 'NoneType' object has no attribute 'recv_ready'
My code:
#!/bin/python3
# Modules and functions to import
from getpass import getpass #to hide password
from selectors import BaseSelector
from time import sleep
from netmiko import ConnectHandler, SSHDetect, redispatch #for ssh
import os #for ping
# Enable netmiko logging
import logging
logging.basicConfig(filename='test.log', level=logging.DEBUG)
logger = logging.getLogger("netmiko")
# Get login credentials
user = input("Username: ")
password = getpass("Password: ")
# Define list of commands
list_cmds = open('reload_cmds.txt').read().split('&')
layer_1 = list_cmds[1]
layer_2 = list_cmds[3]
layer_3_ospf = list_cmds[5]
layer_3_ospfv3 = list_cmds[6]
layer_3_bgp = list_cmds[7]
# Defining check for different layers as function
## Run LAYER 1 precheck commands
def layer_1_check():
print('\n#################### Layer 1 ###################')
for command in layer_1.splitlines():
layer1_output = ssh_connect.send_command(command)
if 'Invalid' in layer1_output:
print(f'========= {command} =========')
print('Invalid command\n')
else:
print(f'========= {command} =========')
print(layer1_output)
## Run LAYER 2 precheck commands
def layer_2_check():
print('\n#################### Layer 2 ###################')
for command in layer_2.splitlines():
layer2_output = ssh_connect.send_command(command)
if 'Invalid' in layer2_output:
print(f'========= {command} =========')
print('Invalid command\n')
else:
print(f'========= {command} =========')
print(layer2_output)
## Run LAYER 3 precheck commands
def layer_3_check():
print('\n#################### Layer 3 ###################')
layer3_show_ip_pro = ssh_connect.send_command("show ip protocols")
print('========= show ip protocols =========')
print(layer3_show_ip_pro)
# run commands based on routing protocols
# ospf
if 'ospf ' in layer3_show_ip_pro:
for command in layer_3_ospfv3.splitlines():
layer3_output = ssh_connect.send_command(command)
if 'Invalid' in layer3_output:
print(f'========= {command} =========')
print('Invalid command\n')
else:
print(f'========= {command} =========')
print(layer3_output)
# ospfv3
if 'ospfv3' in layer3_show_ip_pro:
for command in layer_3_ospfv3.splitlines():
layer3_output = ssh_connect.send_command(command)
if 'Invalid' in layer3_output:
print(f'========= {command} =========')
print('Invalid command\n')
else:
print(f'========= {command} =========')
print(layer3_output)
# bgp
if 'bgp' in layer3_show_ip_pro:
for command in layer_3_bgp.splitlines():
layer3_output = ssh_connect.send_command(command)
if 'Invalid' in layer3_output:
print(f'========= {command} =========')
print('Invalid command\n')
else:
print(f'========= {command} =========')
print(layer3_output)
# Define reload function
def reload():
proceed = input('\nWould you like to proceed with reload?[Type yes or no]: ')
if proceed == 'yes':
print('\n========= Saving configuration =========\n')
reload_output = ssh_connect.save_config()
print(reload_output)
print('\n========= Reloading the switch =========\n')
reload_output = ssh_connect.send_command(
command_string='reload in 001',
expect_string=r'confirm'
)
print(reload_output)
# reload_output += ssh_connect.send_command('\n') # Troubleshoot
# print(reload_output) # Troubleshoot
ssh_connect.disconnect()
print('Disconnected')
else:
ssh_connect.disconnect()
# Define ping function to find out when the device comes back online
def ping():
print(f'\n========= Pinging {ipv4} every 60 secs =========')
# sleep(5) # Troubleshoot
# remove the '.0' in '100.0%' for linux
ping_cmd = os.popen(f'ping -c 1 -W 1 {ipv4} | grep -q "100.0% packet loss" && echo "0" || echo "1"').read().splitlines()
ping_response = ping_cmd[0]
# print(ping_response)
if ping_response == "0":
print(f'{ipv4} is unreachable')
sleep(10)
ping()
elif ping_response == "1":
print(f'\n{ipv4} is back online\n')
print('\n############### Post-Verification ###############\n')
# sleep(10)
ssh_connect = ConnectHandler(**host)
print('Reconnected') # Troubleshoot
print(f'\n {host}') # Troubleshoot
print(f'\n {ssh_connect}') # Troubleshoot
layer_1_check()
layer_2_check()
layer_3_check()
ssh_connect.disconnect()
# print('End of ping() ') # Troubleshoot
else:
pass
# Define list of devices
ipv4_list = open('input.txt')
list_ips = ipv4_list.read().splitlines()
# print(list_ips)
for ipv4 in list_ips:
# Define host attributes
host = {
'device_type': 'autodetect',
'ip': ipv4 ,
# 'port': '7663',
'username': user,
'password': password
}
# print(ipv4)
# Auto-detect device type and update
guesser = SSHDetect(**host)
best_match = guesser.autodetect()
if best_match == 'cisco_ios':
print('################################################')
print(f'########## Connecting to {ipv4} ##########')
print('################################################')
host['device_type'] = best_match
ssh_connect = ConnectHandler(**host)
print('\n############### Pre-Verification ###############\n')
layer_1_check()
layer_2_check()
layer_3_check()
reload()
# Wait for the switch to die !!! You have 60 secs to change your mind.
print('Waiting 60 seconds') # Troubleshoot
sleep(60)
ping()
else:
print(f'\nThe platform for the device with ip {ipv4} is {best_match} which is not supported by the script.\n')
pass
You have a function scoping issue--you create your original ssh_connect variable at the global scope (inside best_match == "cisco_ios" conditional). You then kill that SSH connection after the reload (the Netmiko .disconnect() call will set this ssh_connect variable to None).
You then create a new ssh_connect variable, but you do it inside of your ping function (and do NOT pass it as an argument to layer_1_check(), layer_2_check(), layer_3_check().
Or worded differently, you have two ssh_connect variables--one that is only known inside of the ping_function and one that is known in global scope (main scope). The one in the global scope is the one being used by layer_[123]_check and that one is dead and set to None.
I pretty much always pass variables into functions (except for CONSTANTS) or alternatively make a class/objects.