(Denne artikkelen var tidligere en del av Bluetree.no. Siden Sicra og Bluetree har slått seg sammen, er nå innhold fra Bluetree overført til Sicra.)

[My journey to CCIE Automation #4] Automating network discovery and reports with Python and Ansible is part of a series following my CCIE Automation journey. In the previous post, I worked with NETCONF and an Orchestration API. In this post, I focus on automating network discovery and reporting with Python and Ansible.

Blog #4

After NETCONF in blog #3, I wanted to pick something network engineers often do manually — discovering devices, collecting facts, and documenting neighbors — and automate it with Python and Ansible.

The project in this post is network discovery and reports. A small workflow that scans a subnet, discovers devices, runs commands, and generates a nice HTML report.

What I built

1. Python Discovery script

A Python CLICK app (network_discovery.py) that:

• Scans a subnet for devices with SSH open.
• Logs in with username/password using Netmiko.
• Detects whether the device runs IOS or NX-OS.
• Builds an Ansible inventory file with the correct ansible_network_os.
• Executes an Ansible playbook that will gather facts about the discovered hosts:
  - Hostname
  - Hardware model
  - Software version
  - CDP/LLDP
• Then generate a HTML report listing the discovered hosts and the facts gathered.

Sample from script (see repo for full details:

2. Ansible playbook

The playbook (gather_device_facts.yml) runs against the discovered hosts and gathers system + neighbor info and generates a HTML report.

Sample of gathering data from the discovered hosts:

Right now it only supports Cisco IOS and Nexus, but it can easily be extended to other platforms.

3. HTML Raport

Instead of raw CLI output, I render a single HTML report with a Jinja2 template. Every device is listed in a table, with expandable CDP/LLDP sections.

Sample from jinja2 template:

4. The result – View the HTML report

You get a list of all hosts discovered with a column for:

• IP
• Hostname
• Model
• Version
• OS

At the end you get a list of all CDP and/or LLDP neighbors for each device discovered.

How to run

Se README i GitLab-repositoriet.

Service Interactions update

I've updated the new use case to the Nautix diagram.

What's next

In blog #5 I will focus on working with pyATS:

Blueprint item 3.3 Modify and troubleshoot an automated test by using pyATS to meet requirements

3.3.a Create a testbed file for connecting to Cisco IOS,  IOS XE, or NX-OS devices

3.3.b Gather current configuration and operational state from devices using the Genie parsers and models included with pyATS

3.3.c Develop and execute test jobs and scripts using AEtest to verify network health

Useful links

• GitLab Repo – My CCIE Automation Code
• Ansible documentation

Blog series

• [My journey to CCIE Automation #1] Intro + building a Python CLI app

• [My journey to CCIE Automation #2] Inventory REST API and microservices architecture

• [My journey to CCIE Automation #3] Orchestration API and NETCONF

• [My journey to CCIE Automation #5] Building network pipelines for reliable changes with pyATS and GitLab CI

• [My journey to CCIE Automation #6] Automating Cisco ACI deployments with Terraform, Vault and GitLab CI

• [My journey to CCIE Automation #7] Exploring Model-Driven Telemetry for real-time network insights

• [My journey to CCIE Automation #8] Exploring ThousandEyes and automating Enterprise Agent deployment

• [My journey to CCIE Automation #9] Applying OWASP Secure Coding Practices

• [My journey to CCIE Automation #10] From Docker Compose to Kubernetes