Nornir

Nornir is an open-source, pure-Python automation framework built specifically for network engineering and multi-device orchestration.

Running Nornir on Kriten

To run Nornir on Kriten, you need a container image with Nornir and any other pre-reqs installed, and your Nornir code.

Nornir example

Clone the kriten-community-toolkit repository

git clone https://github.com/kriten-io/kriten-community-toolkit.git

Edit the files in the nornir directory.

Path	Instructions
inventory/hosts.yml	Set the host names and IP addresses of devices in your network. Assign each device to a group.
inventory/groups.yml	Set to dictionary of group names.
inventory/defaults.yml	Set netmiko platform and credentials for your hosts.

This is a simple script for demonstration purposes, please don't store credentials in production!

In the script sh-ip-int.py variable group is read from EXTRA_VARS.

nr.filter(...) dynamically filters the inventory down to only devices that belong to that specific group.

switch_group.run(...) runs the "sh ip int brief" command concurrently, but only on the filtered subset of devices.

import json
import os
from nornir import InitNornir
from nornir_utils.plugins.functions import print_result
from nornir_netmiko import netmiko_send_command
from nornir.core.filter import F

extra_vars = os.environ.get('EXTRA_VARS')

nr = InitNornir(config_file="./config.yml")

if extra_vars:
    extra_vars_data = json.loads(extra_vars)
    group = extra_vars_data["group"]
    switch_group = nr.filter(F(groups__contains=group))
    result = switch_group.run(netmiko_send_command, command_string="sh ip int brief")
else:
    result = nr.run(netmiko_send_command, command_string="sh ip int brief")

print_result(result)

Save your code to your own git repository.

Build a container image (or use ours)

Use the Dockerfile to build a container image and push it to the registry used by your k8s cluster. We have a public image on dockerhub at kubecodeio/nornir:3.5.0

Add a runner in Kriten

Field	Value
name	nornir-3.5.0
image	kubecodeio/nornir:3.5.0
gitURL	https://github.com/kriten-io/kriten-community-toolkit.git
branch	main

Add a task in Kriten

Field	Value
name	nornir-sh-ip-int
runner	nornir-3.5.0
command	cd nornir; python sh-ip-int.py
schema
{ "properties": { "group": { "enum": [ "LEAF", "SPINE" ], "type": "string" } }, "required": [ "group" ] }

Run task

View job output