Building a Python-Based HTTP Server for Over-the-Air File Transfers to Network Devices

Greetings, Tech Talkers!

This is Tor from Tors Tech Talk, Your Trusted Network Engineering Uplink. Today, we’re diving into a powerful but simple concept: building a Python-based HTTP server to facilitate over-the-air file copying to network devices. Specifically, I’ll show you how to create a server that allows you to copy files from anywhere, anytime! We have all been there, we need to copy a file over to a switch or router but setting up a TFTP server can be annoying. Well, using HTTP/S is an option! Did you know - You can copy a file using http/s to a Cisco IOS-XE or Nexus device?

By the end of this tutorial, you’ll have your own lightweight HTTP server that can serve files directly to your devices over the network or even over the internet (be sure to use https for that!) Let’s get started!

Why Python?

Python is a great choice for building an HTTP server because it’s lightweight, easy to set up, and has built-in libraries that handle many of the nitty-gritty details. We’ll be leveraging Python’s http.server module, which is perfect for simple file-serving tasks.

Step 1: Setting up Python’s HTTP Server

Python comes with a built-in module called http.server, which can be used to serve files from a directory. First, let’s create a basic server that will allow us to host files over HTTP.

Here’s a simple Python script to set up an HTTP server in a specified directory:

# Import the required module

from http.server import SimpleHTTPRequestHandler, HTTPServer

# Define the server address and port

server_address = ('', 8080)  # '' means the server listens on all available network interfaces

# Set up the HTTP server

httpd = HTTPServer(server_address, SimpleHTTPRequestHandler)

# Print a message to indicate the server is running

print("Serving HTTP on port 8080...")

# Start the server

httpd.serve_forever()

How This Works:

• HTTPServer: This class binds the server to the address and port specified. In this case, we’re using port 8080, but you can change it to any port.

• SimpleHTTPRequestHandler: This handles the requests sent to the server. By default, it serves files from the directory in which the script is running.

Step 2: Organizing Files for Transfer

Now that you’ve got your server running, you need to place the files you want to serve in the same directory as the Python script. For instance, if you want to allow your network device to download config.txt, just make sure that file is in the same folder.

Example Directory Structure:

/path/to/server/

    ├── server.py   # Your HTTP server script

    ├── config.txt  # The file to be copied to network devices

Step 3: Accessing Files from Network Devices

Let’s say you’ve placed a configuration file called config.txt in the directory and your HTTP server is running on IP 192.168.1.100 on port 8080. To copy this file to your network device's bootflash, you’d run the following command on the device:

copy https://192.168.1.100:8080/config.txt bootflash:

Here’s what happens:

1. The network device initiates an HTTP request to the Python server.

2. The server responds by sending the config.txt file.

3. The device writes the file to its bootflash.

   
   

Step 4: Adding Security (Optional)

In some environments, you might want to secure the file transfer process. You can quickly add basic HTTPS support using Python’s ssl module.

import ssl

from http.server import SimpleHTTPRequestHandler, HTTPServer

# Define the server address and port

server_address = ('', 8443)  # 8443 is a common port for HTTPS

# Set up the HTTP server

httpd = HTTPServer(server_address, SimpleHTTPRequestHandler)

# Wrap the server socket with SSL

httpd.socket = ssl.wrap_socket(httpd.socket, certfile='path/to/cert.pem', keyfile='path/to/key.pem', server_side=True)

# Print a message to indicate the server is running

print("Serving HTTPS on port 8443...")

# Start the server

httpd.serve_forever()

In this example, we’re wrapping the server’s socket with SSL, allowing you to serve files securely using HTTPS. You’d just need to provide a valid SSL certificate and private key.

Step 5: Testing the Server

After setting up your Python HTTP server and placing the necessary files, test it by copying a file to one of your network devices:

copy https://192.168.1.100:8443/config.txt bootflash:

Ensure the device can reach your server’s IP and port, and voilà—you’re transferring files like a networking pro!

Conclusion

There you have it, Tech Talkers! With a few lines of Python, you can spin up an HTTP server to deliver files to your network devices over the air. Whether you’re managing configurations, firmware, or troubleshooting logs, this approach provides a flexible, lightweight, and easy-to-implement solution.

If you found this helpful, be sure to stay tuned for more networking tips and tricks from Tor’s Tech Talk.

As always, I’m your trusted network engineering uplink, helping you keep those packets flowing smoothly. Until next time!

Tor from Tors Tech Talk