Book Image

Mastering Python Networking

Book Image

Mastering Python Networking

Overview of this book

This book begins with a review of the TCP/ IP protocol suite and a refresher of the core elements of the Python language. Next, you will start using Python and supported libraries to automate network tasks from the current major network vendors. We will look at automating traditional network devices based on the command-line interface, as well as newer devices with API support, with hands-on labs. We will then learn the concepts and practical use cases of the Ansible framework in order to achieve your network goals. We will then move on to using Python for DevOps, starting with using open source tools to test, secure, and analyze your network. Then, we will focus on network monitoring and visualization. We will learn how to retrieve network information using a polling mechanism, ?ow-based monitoring, and visualizing the data programmatically. Next, we will learn how to use the Python framework to build your own customized network web services. In the last module, you will use Python for SDN, where you will use a Python-based controller with OpenFlow in a hands-on lab to learn its concepts and applications. We will compare and contrast OpenFlow, OpenStack, OpenDaylight, and NFV. Finally, you will use everything you’ve learned in the book to construct a migration plan to go from a legacy to a scalable SDN-based network.
Table of Contents (22 chapters)
Title
Humble Bundle
Credits
Foreword
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
12
OpenStack, OpenDaylight, and NFV

Group and host variables


Notice in the previous playbook, we have repeated ourselves in the username and password variables for the two devices under the nexus_devices variable:

    vars:
      nexus_devices: {
        "nx-osv-1": {
          "hostname": "nx-osv-1",
          "username": "cisco",
          "password": "cisco",
          "vlans": [100, 200, 300],
        <skip>
        "nx-osv-2": {
          "hostname": "nx-osv-2",
          "username": "cisco",
          "password": "cisco",
          "vlans": [100, 200, 300],
        <skip>

This is not ideal. If we ever need to update the username and password values, we will need to remember to update at two locations. This increases the management burden as well as the chances of making mistakes if we ever forget to update all the locations. For best practice, Ansible suggests that we use group_vars and host_vars directories to separate out the variables.

Note

For more Ansible best practices, check out http://docs.ansible.com...