[Day #62 Pyats Series] Building device health dashboard using Flask + pyATS using pyATS for Cisco [Python for Network Engineer]

[Day #62 Pyats Series] Building device health dashboard using Flask + pyATS using pyATS for Cisco [Python for Network Engineer]

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Introduction on the Key Points

Welcome back to Day 62 of the 101 Days of pyATS Series! Today, we’re diving into something that makes every network engineer’s life easier — a real-time device health dashboard built using Flask + pyATS for Cisco devices.

Whether you’re monitoring interface errors, CPU/memory usage, or environmental health, combining Flask with pyATS Genie parsers gives you a flexible way to create visually appealing, real-time dashboards. This not only reduces manual CLI digging but also brings vendor-agnostic automation to your fingertips.

This use case is especially valuable if you’re learning Python for Network Engineer roles, and want to go beyond just pulling data — you want to visualize it in a sleek dashboard with minimal overhead.

In today’s blog, we’ll:

  • Use pyATS to collect device health data
  • Parse that data using Genie parsers
  • Serve it on a Flask web dashboard
  • Make it dynamic & refreshable
  • Provide complete workflow and CLI validation

Let’s dive in!

Topology Overview

Our topology is kept intentionally simple for this use case:

  • Laptop runs Python + Flask + pyATS.
  • Router is any Cisco IOS-XE capable device.
  • Communication over SSH (port 22) using testbed YAML credentials.

This topology is scalable — you can connect to 5 or 50 routers using the same script and iterate over the results.

Topology & Communications

Devices:

  • Device Type: Cisco IOS-XE
  • Access Method: SSH
  • Authentication: Username + Password

Software Requirements:

  • pyATS, genie, Flask, threading, json, yaml, os
  • Python 3.8+

Key Communications:

  • pyATS establishes SSH connection to devices via testbed YAML
  • Genie learns device health info using device.parse() methods
  • Flask renders this data via Jinja2 templates in real-time

Workflow Script

Let’s write our script: health_dashboard.py

from flask import Flask, render_template
from genie.conf import Genie
from threading import Thread
import time
import json

app = Flask(__name__)

# Load testbed
testbed = Genie.init('testbed.yml')

# Device health status dictionary
device_status = {}

# Background thread to fetch health data
def monitor_devices():
    while True:
        for device_name, device in testbed.devices.items():
            try:
                device.connect(log_stdout=False)
                parsed_output = {
                    "interfaces": device.parse("show interfaces"),
                    "cpu": device.parse("show processes cpu"),
                    "memory": device.parse("show processes memory"),
                    "environment": device.parse("show environment all")
                }
                device_status[device_name] = parsed_output
                device.disconnect()
            except Exception as e:
                device_status[device_name] = {"error": str(e)}
        time.sleep(60)

# Launch background thread
thread = Thread(target=monitor_devices)
thread.daemon = True
thread.start()

@app.route('/')
def index():
    return render_template("dashboard.html", status=device_status)

if __name__ == '__main__':
    app.run(host='0.0.0.0', port=5000, debug=True)

Also, create a templates/dashboard.html file:

<!DOCTYPE html>
<html>
<head>
    <title>Device Health Dashboard</title>
</head>
<body>
    <h1>Device Health Dashboard</h1>
    {% for device, data in status.items() %}
        <h2>{{ device }}</h2>
        {% if data.error %}
            <p style="color:red;">Error: {{ data.error }}</p>
        {% else %}
            <pre>{{ data | tojson(indent=2) }}</pre>
        {% endif %}
    {% endfor %}
</body>
</html>

Explanation by Line

  • Genie.init('testbed.yml'): Initializes testbed YAML and builds device list.
  • device.connect(): Establishes SSH connection.
  • device.parse(...): Parses CLI output into structured Python dict.
  • device_status: Shared dictionary storing parsed device status.
  • Flask: Serves dashboard on browser with Jinja2 templating.
  • Thread(target=monitor_devices): Fetches data every 60s in background.

This allows us to build a live-updating web dashboard without overwhelming device CLI with requests.

testbed.yml Example

testbed:
  name: HealthTestbed

devices:
  cisco1:
    os: iosxe
    type: router
    connections:
      cli:
        protocol: ssh
        ip: 192.168.100.1
        port: 22
    credentials:
      default:
        username: admin
        password: admin123

Post-validation CLI Screenshots (Real Expected Output)

Sample Output from Web Dashboard:

jsonCopyEdit{
  "interfaces": {
    "GigabitEthernet1": {
      "counters": {
        "input_errors": 0,
        "output_errors": 0
      },
      "oper_status": "up"
    }
  },
  "cpu": {
    "five_sec_cpu_total": 5,
    "one_min_cpu_total": 7,
    "five_min_cpu_total": 8
  },
  "memory": {
    "used_memory": "582384K",
    "free_memory": "1032980K"
  },
  "environment": {
    "fan": "ok",
    "temperature": "normal",
    "voltage": "ok"
  }
}

And when device is unreachable:

{
  "error": "Connection refused"
}

FAQs

1. What is the purpose of combining Flask and pyATS in a device health dashboard?

Flask is a lightweight Python web framework used to build REST APIs and web interfaces, while pyATS is Cisco’s network testing and automation framework.
By combining both:

  • pyATS handles device connections, health checks, and data parsing.
  • Flask serves this data in a real-time web dashboard (or API).

This allows network engineers to:

  • Visualize device health metrics (CPU, memory, interfaces, etc.)
  • Integrate REST-based access to inventory or logs
  • Build vendor-specific or multi-vendor dashboards easily

2. Which device health parameters are commonly monitored in such a dashboard?

Common health metrics collected using pyATS/parsers and visualized via Flask include:

  • CPU utilization
  • Memory usage
  • Interface status and errors
  • Device uptime
  • Fan and power supply status
  • Hardware model & serial info
  • Inventory summary (line cards, modules, transceivers)

All this data is parsed using pyATS’s Genie parsers (show version, show processes, show interfaces, etc.).

3. What are the key components required to build this dashboard?

To build a device health dashboard using Flask + pyATS, the following components are typically needed:

ComponentPurpose
Flask AppHosts the frontend and backend API
pyATS Testbed YAMLDefines device credentials and connection parameters
pyATS ScriptsExecutes commands and parses CLI output
HTML/CSS/JSOptional, for frontend UI rendering
Scheduler (optional)For regular polling/health checks (e.g., cron, Celery)

You may also use Jinja2 templates in Flask to render HTML dynamically.

4. How do you securely handle credentials in the Flask + pyATS setup?

Sensitive credentials (like device usernames and passwords) should not be hardcoded. Best practices include:

  • Using environment variables for sensitive info.
  • Storing testbed YAML securely (with limited access).
  • Implementing encryption or vault-based secrets (e.g., HashiCorp Vault, AWS Secrets Manager).
  • Never expose raw pyATS outputs directly via API without sanitizing sensitive fields.

Additionally, Flask routes that provide device data should be authenticated and rate-limited.

5. Can this setup scale for multiple vendors, or is it Cisco-specific?

While pyATS was developed by Cisco, it supports multi-vendor device interaction through:

  • Custom parsers
  • Unstructured CLI parsing
  • RESTCONF/NETCONF integration

The dashboard built with Flask can be extended to:

  • Query Arista, Juniper, FortiGate via REST APIs or CLI
  • Use JSON/YAML normalized outputs from different devices
  • Introduce a vendor field and logic in the backend to call the correct parser or API

So yes, with extra effort, it can be scaled beyond Cisco.

6. How does pyATS return data to Flask—raw or parsed?

pyATS + Genie provides parsed Python dictionary output from CLI commands, which can be easily converted to JSON. Example:

from genie.testbed import load
testbed = load('testbed.yaml')
device = testbed.devices['R1']
device.connect()

parsed_output = device.parse('show version')

This parsed_output can be returned as a JSON response via Flask route:

from flask import Flask, jsonify
app = Flask(__name__)

@app.route('/device/health')
def health():
    return jsonify(parsed_output)

So, Flask never needs to deal with raw CLI—it receives structured dictionaries from pyATS directly.

7. What are some troubleshooting steps if Flask doesn’t show the correct data?

Some common troubleshooting checks:

  • Ensure device credentials in testbed.yaml are valid
  • Verify device.connect() doesn’t throw SSH/Telnet errors
  • Confirm device.parse() is supported for that platform/image
  • Use Flask app.logger for debugging and error tracking
  • Check for stale .pyc or cache files
  • If using threads or async, ensure thread safety in device connection
  • Always test each pyATS command manually before integration

You can also add /debug or /ping endpoints in Flask to validate backend health.

8. Can we integrate historical data and charts into the Flask dashboard?

Yes. For historical trends and charting:

  • Store parsed pyATS data into a database (like SQLite, MongoDB, or InfluxDB)
  • Use charting libraries like Chart.js, Plotly, or D3.js in the frontend
  • Build endpoints like /history/cpu or /metrics/interface to query and plot trends

You could also integrate:

  • Grafana for dashboards if using time-series DBs
  • Celery for scheduling recurring health checks

This transforms the dashboard from just real-time monitoring to full telemetry + historical analytics.

YouTube Link

Watch the Complete Python for Network Engineer: Building device health dashboard using Flask + pyATS using pyATS for Cisco [Python for Network Engineer] Lab Demo & Explanation on our channel:

Master Python Network Automation, Ansible, REST API & Cisco DevNet
Master Python Network Automation, Ansible, REST API & Cisco DevNet
Master Python Network Automation, Ansible, REST API & Cisco DevNet
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Join Our Training

If you’re enjoying this 101 Days of pyATS (Vendor-Agnostic) series, then it’s time to go a step further.

Trainer Sagar Dhawan is conducting a 3-month instructor-led program for network engineers who want to master:

  • Python scripting
  • Ansible automation
  • APIs & DevNet
  • pyATS + Genie + Flask
  • Vendor-agnostic testing & reporting

Course Outline & Registration:
https://course.networkjourney.com/python-ansible-api-cisco-devnet-for-network-engineers

This is the only course designed with real-world projects, EVE-NG topologies, multi-vendor use cases, and a focus on Python for Network Engineer profiles.

Don’t miss your chance to upskill. Seats are limited!

Enroll Now & Future‑Proof Your Career
Email: info@networkjourney.com
WhatsApp / Call: +91 97395 21088

Trainer Sagar Dhawan
Hi all, Good to see you here. I'm your Trainer for CCIE, CCNP, CCNA, Firewall batches and many more courses coming up! Stay tuned for latest updates! Keep me posted over Whatsapp/Email about your experience learning from us. Thanks for being part of - "Network Journey - A journey towards packet-life!!!"

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