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)
16
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17
Index

Ansible loops

Ansible provides a number of loops in the playbook, such as standard loops, looping over files, sub-elements, do-until, and many more. In this section, we will look at two of the most commonly used loop forms: standard loops and looping over hash values.

Standard loops

Standard loops in playbooks are often used to easily perform similar tasks multiple times. The syntax for standard loops is very easy: the {{ item }} variable is the placeholder looping over the with_items list. In our next example, chapter5_4.yml, we will loop over the items in the with_items list with the echo command from our localhost.

$ cat chapter5_4.yml 
---
- name: Echo Loop Items
  hosts: "localhost"
  gather_facts: false

  tasks:
    - name: echo loop items
      command: echo "{{ item }}"
      with_items:
        - 'r1'
        - 'r2'
        - 'r3'
        - 'r4'
        - 'r5&apos...