Book Image

Python Network Programming Techniques

By : Marcel Neidinger
Book Image

Python Network Programming Techniques

By: Marcel Neidinger

Overview of this book

Network automation offers a powerful new way of changing your infrastructure network. Gone are the days of manually logging on to different devices to type the same configuration commands over and over again. With this book, you'll find out how you can automate your network infrastructure using Python. You'll get started on your network automation journey with a hands-on introduction to the network programming basics to complement your infrastructure knowledge. You'll learn how to tackle different aspects of network automation using Python programming and a variety of open source libraries. In the book, you'll learn everything from templating, testing, and deploying your configuration on a device-by-device basis to using high-level REST APIs to manage your cloud-based infrastructure. Finally, you'll see how to automate network security with Cisco’s Firepower APIs. By the end of this Python network programming book, you'll have not only gained a holistic overview of the different methods to automate the configuration and maintenance of network devices, but also learned how to automate simple to complex networking tasks and overcome common network programming challenges.
Table of Contents (14 chapters)

Using for-loops in Jinja2 to configure an access list

While we can already achieve a lot by being able to pass information from our Python file into a template and use this information in there, this is something that could be done with standard Python strings.

The true power of Jinja2 lies in its ability to include logic in the template. Basically, Jinja2 templates can also be seen as programs written in the Jinja2 template language.

This language supports such constructs as for-loops and if-clauses, which we have already seen in Python. This means that instead of copy-pasting the same text over and over and only changing one small part of it, we can create loops to make this more compact, readable, and changeable.

In this recipe, you'll see how to take two lists of IP addresses that are provided in your Python file and create an ACL for all the IPs in both lists, denying access for the IPs in one list while allowing access for IPs in the other list.

Getting ready...