The foremost is to be setup TextFSM correctly for Netmiko to work. The official site (Netmiko & NTC )explains a method that didn’t really work for me. I have tried to set up TextFSM using pip install ntc_templates and also using git clone but none of them particularly worked for me out of the box. This method below is what I have found to work most reliably. Let’s see how to parse data with the netmiko text plugin.
STEP1:-
In whichever directly you have your netmiko script, git clone the ntc-templates repository.
Step2:- Tell Netmiko where to find the textfsm templates.
from netmiko import ConnectHandler
from pprint import pprint
import os
# set templates directory to the path where index file is located. If you open templates directory
# there is an index file which is what netmiko is looking to find to work properly.
templates = os.path.dirname(os.path.abspath(__file__)) + '/ntc-templates/ntc_templates/templates'
os.environ['NET_TEXTFSM']= templates
# set the environment variable NET_TEXTFSM to this directory which is again what Netmiko expectsStep3:- Modify the send_command( ) method you are using to add use_textfsm=True as an argument
from netmiko import ConnectHandler
from pprint import pprint
import os
templates = os.path.dirname(os.path.abspath(__file__)) + '/ntc-templates/ntc_templates/templates'
os.environ['NET_TEXTFSM']= templates
csr1000v1 = {
'device_type': 'cisco_ios',
'host': 'sandbox-iosxe-latest-1.cisco.com',
'username': 'developer',
'password': 'C1sco12345',
'port' : 22, # optional, defaults to 22
'secret': 'C1sco12345', # optional, defaults to ''
}
csr1000v2 = {
'device_type': 'cisco_ios',
'host': 'sandbox-iosxe-recomm-1.cisco.com',
'username': 'developer',
'password': 'C1sco12345',
'port' : 22,
'secret': 'C1sco12345',
}
iosxrv9000 = {
'device_type': 'cisco_xr',
'host': 'sandbox-iosxr-1.cisco.com',
'username': 'admin',
'password': 'C1sco12345',
'port' : 22,
'secret': 'C1sco12345',
}
nxosv9000 = {
'device_type': 'cisco_nxos',
'host': 'sandbox-nxos-1.cisco.com',
'username': 'admin',
'password': 'Admin_1234!',
'port' : 22,
'secret': 'Admin_1234!',
}
all_devices = [csr1000v1, csr1000v2, iosxrv9000, nxosv9000]
for device in all_devices:
net_connect = ConnectHandler(**device)
print(net_connect.host)
print(net_connect.send_command('show ver', use_textfsm=True)) ## use_textfsm=True
╰─ python3 script5.py ─╯
sandbox-iosxe-latest-1.cisco.com
[{'version': '17.3.1a', 'rommon': 'IOS-XE', 'hostname': 'csr1000v-1', 'uptime': '1 day, 5 hours, 22 minutes', 'uptime_years': '', 'uptime_weeks': '', 'uptime_days': '1', 'uptime_hours': '5', 'uptime_minutes': '22', 'reload_reason': 'reload', 'running_image': 'packages.conf', 'hardware': ['CSR1000V'], 'serial': ['9ESGOBARV9D'], 'config_register': '0x2102', 'mac': [], 'restarted': ''}]
sandbox-iosxe-recomm-1.cisco.com
[{'version': '16.9.3', 'rommon': 'IOS-XE', 'hostname': 'csr1000v-1', 'uptime': '2 days, 20 hours, 8 minutes', 'uptime_years': '', 'uptime_weeks': '', 'uptime_days': '2', 'uptime_hours': '20', 'uptime_minutes': '8', 'reload_reason': 'reload', 'running_image': 'packages.conf', 'hardware': ['CSR1000V'], 'serial': ['926V75BDNRJ'], 'config_register': '0x2102', 'mac': [], 'restarted': ''}]
sandbox-iosxr-1.cisco.com
[{'version': '6.5.3', 'uptime': '2 weeks 1 day 23 hours 28 minutes', 'location': '/opt/cisco/XR/packages/', 'hardware': 'IOS-XRv 9000', 'build_host': 'iox-ucs-019'}]
sandbox-nxos-1.cisco.com
[{'uptime': '10 day(s), 23 hour(s), 35 minute(s), 44 second(s)', 'last_reboot_reason': 'Unknown', 'os': '9.3(3)', 'boot_image': 'bootflash:///nxos.9.3.3.bin', 'platform': 'C9300v', 'hostname': 'sbx_nxosv1', 'serial': '9N3KD63KWT0'}]IMPORTANT:- It is advisable to use the full command name while using any parser plugin like textfsm, ttp, or genie. While certain well-known commands may work with abbreviations with parsers like textfsm understands show version and show ver, other commands might not work.
To make the data look neat, we can convert the output into JSON format simply by below modifications
import json ## add this to other imports
all_devices = [csr1000v1, csr1000v2, iosxrv9000, nxosv9000]
for device in all_devices:
net_connect = ConnectHandler(**device)
output = net_connect.send_command('show version', use_textfsm=True)
print(json.dumps(output, indent=4, sort_keys=True)) ## convert the return data into JSON
[
{
"config_register": "0x2102",
"hardware": [
"CSR1000V"
],
"hostname": "csr1000v-1",
"mac": [],
"reload_reason": "reload",
"restarted": "",
"rommon": "IOS-XE",
"running_image": "packages.conf",
"serial": [
"9ESGOBARV9D"
],
"uptime": "1 day, 7 hours, 42 minutes",
"uptime_days": "1",
"uptime_hours": "7",
"uptime_minutes": "42",
"uptime_weeks": "",
"uptime_years": "",
"version": "17.3.1a"
}
]
[
{
"config_register": "0x2102",
"hardware": [
"CSR1000V"
],
"hostname": "csr1000v-1",
"mac": [],
"reload_reason": "reload",
"restarted": "",
"rommon": "IOS-XE",
"running_image": "packages.conf",
"serial": [
"926V75BDNRJ"
],
"uptime": "2 days, 22 hours, 28 minutes",
"uptime_days": "2",
"uptime_hours": "22",
"uptime_minutes": "28",
"uptime_weeks": "",
"uptime_years": "",
"version": "16.9.3"
}
]
[
{
"build_host": "iox-ucs-019",
"hardware": "IOS-XRv 9000",
"location": "/opt/cisco/XR/packages/",
"uptime": "2 weeks 2 days 1 hour 48 minutes",
"version": "6.5.3"
}
]
[
{
"boot_image": "bootflash:///nxos.9.3.3.bin",
"hostname": "sbx_nxosv1",
"last_reboot_reason": "Unknown",
"os": "9.3(3)",
"platform": "C9300v",
"serial": "9N3KD63KWT0",
"uptime": "11 day(s), 1 hour(s), 55 minute(s), 45 second(s)"
}
]All the heavy lifting of writing a custom regular expression to catch all matches coupled with the fact that you also take multiple platforms and output formats into account. All that is left to be done now is put it into a well-formatted excel sheet for later reference. See other posts on how to work with CSV and EXCEL files with python for network automation engineers.
Use vanilla TextFsm
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