book

Python Network Programming Techniques

by Marcel Neidinger

October 2021

Intermediate to advanced

340 pages

6h 51m

English

Packt Publishing

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Who this book is forWhat this book coversTo get the most out of this bookDownload the example code filesCode in ActionDownload the color imagesConventions usedGet in touchReviewsShare Your Thoughts
Technical requirementsAssigning variables in PythonGetting readyHow to do it…How it works…Converting between data types in PythonGetting readyHow to do it…How it works…Looping over lists in PythonGetting readyHow to do it…How it works…There's more…Controlling the flow of a Python program using if statementsGetting readyHow to do it…How it works…There's more…Executing code until a condition is met using while loopsGetting readyHow to do it…How it works…There's more…Writing reusable code with functionsGetting readyHow to do it…How it works…There's more…Storing and accessing key-value pairs using dictionariesGetting readyHow to do it…How it works…There's more…Importing modules from the standard libraryGetting readyHow to do it…How it works…There's more…Installing modules from the PyPIGetting readyHow to do it…How it works…
Technical requirements Initiating an SSH session with ParamikoGetting readyHow to do it...How it works...There's more...Executing a command via SSHGetting readyHow to do it...How it works...Reading the output of an executed commandGetting readyHow to do it...How it works...There's more...Executing the same command against multiple devicesGetting readyHow to do it...How it works...Executing a sequence of commandsGetting readyHow to do it...How it works...Using public/private keys for authenticationGetting readyHow to do it...How it works...There's more...Loading local SSH configurationGetting readyHow to do it...How it works...
Technical requirementsLoading Jinja2 templates in PythonGetting readyHow to do it...How it works...There's more...Passing variables from Python to a templateGetting readyHow to do it...How it works...There's more...Writing your rendered template to a fileGetting readyHow to do itHow it works...Using for-loops in Jinja2 to configure an access listGetting readyHow to do it...How it works...There's more...Creating a port configuration template using if-clauses in Jinja2Getting readyHow to do it...How it works...There's more...Creating modular templates using Jinja2's import methodsGetting readyHow to do it...How it works...There's more...Using Python functions from within your template with Jinja2 filtersGetting readyHow to do it...How it works...There's more...Structuring your configuration template with blocks and template inheritanceGetting readyHow to do it...How it works...There's more...
Technical requirements Connecting to a network device using netmikoGetting readyHow to do it...How it works...There's more...Sending commands using netmikoGetting readyHow to do it...How it works...Retrieving command outputs as structured Python data using netmiko and Genie Getting readyHow to do it...How it works...Gathering facts using netmikoGetting readyHow to do it...How it works...There's more...Connecting to multiple devicesGetting readyHow to do it...How it works...There's more...Creating and applying a configuration template with Jinja2 and netmikoGetting readyHow to do it...How it works...There's more...Copying files to a device using netmikoGetting readyHow to do it...How it works...There's more...Escalating privileges with netmikoGetting readyHow to do it...How it works...Authenticating using public-private keys with netmikoGetting readyHow to do it...How it works...Handling commands that prompt for information using netmiko Getting readyHow to do it...How it works...There's more...
Technical requirementsRevisiting the NETCONF and YANG modulesConnecting to a network device using ncclientGetting readyHow to do it…How it works…Using NETCONF and ncclient to retrieve the running configurationGetting readyHow to do it…How it works…There's more…Using NETCONF and ncclient to change the starting configurationGetting readyHow to do it…How it works…Retrieving an interface configuration using NETCONF and ncclientGetting readyHow to do it…How it works…Changing an interface configuration using NETCONF and ncclientGetting readyHow to do it…How it works…Reacting to event notifications using NETCONF and ncclientGetting readyHow to do it…How it works…
Technical requirementsConnecting to devices from different vendors using NAPALMGetting readyHow to do it…How it works…There's more…Issuing commands to a device using NAPALMGetting readyHow to do it…How it works…Testing network reachability using ping and NAPALMGetting readyHow to do it…How it works…Backing up your device configuration using NAPALMGetting readyHow to do it…How it works…Gathering facts about your network device using NAPALMGetting readyHow to do it…How it works…Creating and applying a configuration template with jinja2 and NAPALMGetting readyHow to do it…How it works…Rolling back configuration changes using NAPALMGetting readyHow to do it…How it works…Validating deployments using NAPALMGetting readyHow to do it…How it works…
Technical requirementsRevisiting the concept of testingCreating a pyATS testbed fileGetting readyHow to do it…How it works…Connecting to your device and issuing commands using pyATSGetting readyHow to do it…How it works…Retrieving your device's current state using pyATSGetting readyHow to do it…How it works…Using Genie Conf objects to create a portable configuration scriptGetting readyHow to do it…How it works…There's more…Comparing your device's current state to a previously learned stateGetting readyHow to do it…How it works…
Technical requirementsRevisiting HTTP's request-response model and RESTCONF principlesHow does HTTP work?How RESTCONF builds on top of HTTPMaking HTTP requests using the requests module in PythonGetting readyHow to do it…How it works…There's more…Retrieving all interfaces of a device using RESTCONF and requestsGetting readyHow to do it…How it works…There's more…Creating a VLAN using RESTCONF and requestsGetting readyHow to do it…How it works…Updating a VLAN using RESTCONF and requestsGetting readyHow to do it…How it works…There's more…Deleting a VLAN using RESTCONF and requestsGetting readyHow to do it…How it works…

Technical requirementsAuthenticating web requestsPassing a username-password combination as authentication data in a requestPassing a token to a request using custom header fieldsStoring authentication metadata between requests using sessionsGetting readyHow to do it…How it works…There's more…Retrieving a list of Meraki networksGetting readyHow to do it…How it works…There's more…Retrieving usage details and connected clients for a Meraki networkGetting readyHow to do it…How it works…There's more…Rebooting a Meraki deviceGetting readyHow to do it…How it works…There's more…Retrieving channel usage for your Meraki access pointGetting readyHow to do it…How it works…There's more…Updating the switchport configuration of a Meraki deviceGetting readyHow to do it…How it works…Deleting the QoS rules on a Meraki deviceGetting readyHow to do it…How it works…There's more…Using webhooks to programmatically react to an AP going downGetting readyHow to do it…How it works…
Technical requirementsSetting up the module structureGetting readyHow to do it…How it works…There's more…Documenting your moduleGetting readyHow to do it…How it works…Passing information into your moduleGetting readyHow to do it…How it works…Using Ansible's built-in functionality to do web requestsGetting readyHow to do it…How it works…Packaging and calling your modules from Ansible playbooksGetting readyHow to do it…How it works…There's more…
Technical requirementsSetting up the library to interact with your AWS accountGetting readyHow to do it…How it works…There's more…Collecting information about your cloud networking resourcesGetting readyHow to do it…How it works…Starting EC2 instancesGetting readyHow to do it…How it works…Creating a VPCGetting readyHow to do it…How it works…There's more…Subnetting your VPCGetting readyHow to do it…How it works…Changing routes in your VPCGetting readyHow to do it…How it works…
Technical requirementsExploring the API ExplorerAuthenticating against the FMC REST APIGetting readyHow to do it…How it works…There's more…Retrieving access policiesGetting readyHow to do it…How it works…Changing access policiesGetting readyHow to do it…How it works…Retrieving access rulesGetting readyHow to do it…How it works…Changing access rulesGetting readyHow to do it…How it works…Deleting access rulesGetting readyHow to do it…How it works…
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Content preview from Python Network Programming Techniques

Chapter 3: Building Configuration Templates Using Jinja2

Configurations are the lifeblood of networking devices and could be, to draw a relation to software engineering, regarded as the source code of a network. When writing such configuration files, it can be handy to build templates that parts can be reused from. In this chapter, we will see how we can programmatically build and render such templates using a templating language called Jinja2.

The applications of this are manifold. Think of a script that reaches out to your IP Address Management (IPAM) system and automatically builds a configuration based on the information and the template you have written. Using sub-templates, you can significantly improve the overall cohesiveness of your ...