Book Image

Mastering Python Networking - Third Edition

By : Eric Chou
Book Image

Mastering Python Networking - Third Edition

By: Eric Chou

Overview of this book

Networks in your infrastructure set the foundation for how your application can be deployed, maintained, and serviced. Python is the ideal language for network engineers to explore tools that were previously available to systems engineers and application developers. In Mastering Python Networking, Third edition, you’ll embark on a Python-based journey to transition from traditional network engineers to network developers ready for the next-generation of networks. This new edition is completely revised and updated to work with Python 3. In addition to new chapters on network data analysis with ELK stack (Elasticsearch, Logstash, Kibana, and Beats) and Azure Cloud Networking, it includes updates on using newer libraries such as pyATS and Nornir, as well as Ansible 2.8. Each chapter is updated with the latest libraries with working examples to ensure compatibility and understanding of the concepts. Starting with a basic overview of Python, the book teaches you how it can interact with both legacy and API-enabled network devices. You will learn to leverage high-level Python packages and frameworks to perform network automation tasks, monitoring, management, and enhanced network security followed by Azure and AWS Cloud networking. Finally, you will use Jenkins for continuous integration as well as testing tools to verify your network.
Table of Contents (18 chapters)
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Ansible conditionals

Ansible conditionals are similar to conditional statements in programming languages. In Chapter 1, Review of TCP/IP Protocol Suite and Python, we saw that Python uses conditional statements to execute only a section of the code by using if, then, or while statements. In Ansible, it uses conditional keywords to only run a task when a given condition is met. In many cases, the execution of a play or task may depend on the value of a fact, variable, or the previous task result. For example, if you have a play to upgrade router images, you want to include a step to make sure the new router image is on the device before you move on to the next play of rebooting the router.

In this section, we will discuss the when clause, which is supported for all modules, as well as unique conditional states that are supported in Ansible networking command modules. Some of the conditions are as follows:

  • Equal to (eq)
  • Not equal to (neq)
  • Greater than (gt)
  • Greater...