nornir_scrapli

nornir_scrapli -- scrapli's plugin for nornir.

Table of Contents

• Quick Start Guide
  • Installation
  • A Simple Example
• Supported Platforms
• General Information

Quick Start Guide

Installation

In most cases installation via pip is the simplest and best way to install nornir_scrapli.

pip install nornir-scrapli

A Simple Example

Example inventory file (host/group/default, see "real" Nornir docs for lots more info!):

---
iosxe-1:
  hostname: 172.18.0.11
  connection_options:
    scrapli:
      platform: cisco_iosxe
      port: 22
      extras:
        ssh_config_file: True
        auth_strict_key: False

from nornir import InitNornir
from nornir_scrapli.tasks import (
    get_prompt,
    send_command,
    send_configs
)

nr = InitNornir(config_file="nornir_data/config.yaml")

prompt_results = nr.run(task=get_prompt)
command_results = nr.run(task=send_command, command="show version")
config_results = nr.run(
    task=send_configs,
    configs=["interface loopback123", "description nornir_scrapli was here"],
)

print("get_prompt result:")
print(prompt_results["iosxe-1"].result)
print("send_command result:")
print(prompt_results["iosxe-1"].result)
print("send_configs result:")
print(config_results["iosxe-1"].result)

$ python my_scrapli_script.py
get_prompt result:
3560CX#
send_command result:
Cisco IOS Software, C3560CX Software (C3560CX-UNIVERSALK9-M), Version 15.2(4)E7, RELEASE SOFTWARE (fc2)
<SNIP>
send_configs result:

Supported Platforms

nornir_scrapli supports the "core" scrapli drivers. See scrapli docs for more info.

General Information

Nornir has historically contained it's plugins within the actual Nornir codebase itself, this however is changing. At time of writing (4 April 2020) the end state of how plugins will work is not 100% solidified, but this should get fairly close, and it works with current and hopefully future Nornir!

If you have used Nornir before, this package should be very similar, but not exactly the same. Since the plugins currently/used to live in Nornir you could simply import them from the appropriate package as such:

from nornir.plugins.tasks.networking import netconf_get_config

With nornir_scrapli you simply install this package along side "regular" Nornir, and import the tasks from nornir_scrapli directly:

from nornir_scrapli.tasks import send_command

As soon as a nornir_scrapli task is imported, it (nornir_scrapli) will register as a connection, and things should work as normal from there!

This is obviously all in a "beta" state until Nornir 3.0 is officially released and the template for what plugins should look like is solidified, so use with care!

The last important difference with nornir_scrapli is that in addition to the "normal" data in the Nornir Result object, nornir_scrapli also assigns the scrapli Response object (or list of Response objects) to the scrapli_response attribute. This means that you can access all of the "normal" scrapli response data from this object -- including things like elapsed_time and textfsm_parse_output:

>>> some_nornir_result["sea-ios-1"].scrapli_response.elapsed_time
0.039469
>>> some_nornir_result["sea-ios-1"].scrapli_response.textfsm_parse_output()
[[some structured data back from the device!]]

If you would like to continue using print_result like "normal" in nornir, but would like to see structured data (if available) in the print_result output, you can use the nornir_scrapli print_structured_result function. This function can be imported from the scrapli functions module:

from nornir_scrapli.functions import print_structured_result

This function acts pretty much exactly like the "normal" print result function, but will of course try to print the structured result. By default this will try to use textfsm to parse results, but it is of course configurable via the parser keyword argument. As scrapli will return an empty data structure if parsing fails, this may cause tasks to look like they are getting skipped in the output (nornir's print result function does not print empty lists), if you would like to fall back to printing the unparsed output you can do so by setting the fail_to_string keyword argument to True as follows:

print_structured_result(my_agg_result, parser="genie", fail_to_string=True)