Introduction to Python Network Automation(2021)[Choi][9781484268063]

Table of Contents
About the Author
About the Technical Reviewer
Acknowledgments
Introduction
Chapter 1: Introduction to Python Network Automation
	Laying the Foundation
	Exploring Your Skills and Prerequisites
		General Competencies of Three Main IT Domain Group
		Comparative Analysis of IT Engineers’ Responsibilities
	Python and Network Automation Studies
		Why Do People Want to Learn Python?
	What Do I Need to Study Network Automation Using Python?
	Hardware: Minimum Specifications for Laptop or PC
	Software Requirements
	Building a Network Automation Development Environment Using GNS3
	Downloading Supplementary Guides and Source Code
	Summary
	Storytime 1: Mega Speed Shoe Factory
Chapter 2: Learn Python Basics on Windows
	“Hello, World!” and print() Function in Interactive Mode
	Preparing for the Python Exercises
		Understanding Data Types
		Indentation and Code Blocks
			Explanation
		Commenting
			Explanation
		Python Naming Convention
	Doing the Python Exercises
	Variables and Strings
		Exercise 2-1: Create Variables and Assign Various Data Types
			Explanation
		Exercise 2-2: Create Variables and Use the print() Function to Print Output
			Explanation
		Exercise 2-3: Use Abbreviated Variable Assignment
			Explanation
		Exercise 2-4: Enter a String, Escape Character Backslash (\), and type() Function
			Explanation
		Exercise 2-5: Determine If a Variable Is a Container, a Tag, or a Pointer
			Explanation
		Exercise 2-6: Use String Indexing
			Explanation
		Exercise 2-7: Understand Variable Assignment Errors
			Explanation
		Exercise 2-8: Avoid “SyntaxError: EOL While Scanning String Literal”
			Explanation
		Exercise 2-9: Avoid “NameError: name ‘variable_name’ is not defined”
			Explanation
		Exercise 2-10: Avoid “SyntaxError: invalid syntax”
			Explanation
		Exercise 2-11: Avoid “TypeError: ‘str’ object is not callable”
			Explanation
		Exercise 2-12: Add Multiline Comments with Triple Quotation Marks
			Explanation
		Exercise 2-13: Use \ as an Escape Character to Remove Special Character Meanings
			Explanation
		Exercise 2-14: Enter (Inject) Values/Strings in a String Using %s
			Explanation
	Printing, Concatenating, and Converting Strings
		Exercise 2-15: Use the print() and len() Functions to Create a Simple Function
			Explanation
		Exercise 2-16: Use the lower() and upper() String Methods
			Explanation
		Exercise 2-17: Perform String Concatenation and Use the str() Method
			Explanation
		Exercise 2-18: Learn to Change a String Using Curly Brackets and .format()
			Explanation
		Exercise 2-19: Adjust the Text Position with Curly Brackets and .format()
			Explanation
		Exercise 2-20: Adjust the Number of Decimal Places
			Explanation
		Exercise 2-21: Ask for and Receive User Input with input()
			Explanation
		Exercise 2-22: Change a Word or Characters in a String
			Explanation
		Recap: Variables and Strings
	Numbers and Arithmetic Operators
		Exercise 2-23: Use Arithmetic Operators
			Explanation
		Exercise 2-24: Understand Integers vs. Strings
			Explanation
		Recap: Arithmetic Operators
	Booleans and Relational Operators
		Exercise 2-25: Use Booleans
			Explanation
		Exercise 2-26: Use Relational Operators
			Explanation
		Exercise 2-27: Use Boolean Expressions to Test True or False
			Explanation
		Exercise 2-28: Use Logical (Membership) Operators
			Explanation
		Exercise 2-29: Change the Order of Operation with ()
			Explanation
	Control Statements: if, elif, and else
		Exercise 2-30: Use if and else
			Explanation
		Exercise 2-31: Use if, elif, and else
			Explanation
		Exercise 2-32: Write Code with if, elif, and else
			Explanation
		Recap: Boolean and Conditionals
	Functions
		Exercise 2-33: Defining a Function
			Explanation
		Exercise 2-34: Assign Default Values to a Function
			Explanation
		Exercise 2-35: Define Hello and Goodbye Functions
			Explanation
		Exercise 2-36: Use the Odd or Even Function
			Explanation
		Exercise 2-37: Nest a Function Within a Function
			Explanation
		Recap: Functions
	Lists
		Exercise 2-38: Create a List and Index Items
			Explanation
		Exercise 2-39: Use append, extend, and insert in a List
			Explanation
	Slicing
		Exercise 2-40: Slice a List
			Explanation
	Exceptions and Error Handling
		Exercise 2-41: Avoid a ValueError Error
			Explanation
		Exercise 2-42: Handle Errors with try and except in a List
			Explanation
		Exercise 2-43: Find an Index of an Item in a List with the Customized Exception
			Explanation
		Practicing Lists
		Exercise 2-44: Practice a List
			Explanation
	Using for Loops and while Loops
		Exercise 2-45: Use the for Loop’s upper() and capitalize() Methods
			Explanation
		Exercise 2-46: Use the while Loop and len() Function
			Explanation
	Sorting and Ranges
		Exercise 2-47: Use sort() vs. sorted() in a List
			Explanation
		Exercise 2-48: Link Two Lists
			Explanation
		Exercise 2-49: Find the List Length Using the len() Function
			Explanation
		Exercise 2-50: Use range() and the for Loop
			Explanation
		Exercise 2-51: Use the String List for loop() and range() with Arguments
			Explanation
		Recap: Lists and Loops
	Tuples
		Exercise 2-52: See Some Basic Tuple Examples
			Explanation
		Exercise 2-53: Convert a Tuple to a List
			Explanation
		Exercise 2-54: Determine Whether a Tuple Immutable
			Explanation
		Exercise 2-55: Convert a Tuple to a List and a List to a Tuple
			Explanation
		Exercise 2-56: Use a for Loop in a Tuple
			Explanation
		Exercise 2-57: Assign Multiple Variables to a Tuple
			Explanation
		Exercise 2-58: Create a Simple Tuple Function
			Explanation
		Exercise 2-59: Use Tuples as List Elements
			Explanation
		Recap: Tuples
	Dictionaries
		Exercise 2-60: Understand Dictionary Basics
			Explanation
		Exercise 2-61: Avoid a Dictionary TypeError and Convert Two Lists to a Single Dictionary
			Explanation
		Exercise 2-62: Use Keys to Print Values from a Dictionary
			Explanation
		Exercise 2-63: Change a Dictionary Value
			Explanation
		Exercise 2-64: Add a New Set of Keys and Values to a Dictionary
			Explanation
		Exercise 2-65: Find the Number of Dictionary Elements
			Explanation
		Exercise 2-66: Delete Dictionary Keys and Values
			Explanation
		Exercise 2-67: Write a Python Script with a Dictionary
			Explanation
		Exercise 2-68: Use a Dictionary for a Loop and Formatting
			Explanation
		Recap: Dictionaries
	Handling Files
		Exercise 2-69: Read and Display Hosts File from Your PC
			Explanation
		Exercise 2-70: Open and Close Hosts Files
			Explanation
		Exercise 2-71: Create Code to Close a File in Two Ways
			Explanation
		Exercise 2-72: Create a Text File, and Read, Write, and Print
			Explanation
		Exercise 2-73: Use rstrip() or lstrip() to Remove Whitespace
			Explanation
		Exercise 2-74: Python File Mode Exercise: Use r Mode
			Explanation
		Exercise 2-75: Python File Mode Exercise: Use r+ Mode
			Explanation
		Exercise 2-76: Python File Mode Exercise: Use a Mode
			Explanation
		Exercise 2-77: Python File Mode Exercise: Use a+ Mode
			Explanation
		Exercise 2-78: Python File Mode Exercise: Use w Mode
			Explanation
		Exercise 2-79: Python File Mode Exercise: Use w+ Mode
			Explanation
		Exercise 2-80: Python File Mode Exercise: Use x Mode
			Explanation
		Exercise 2-81: Python File Mode Exercise: Use x Mode
			Explanation
		Exercise 2-82: Open a Byte File in Python
			Explanation
		Exercise 2-83: Handle Errors with try and except
			Explanation
		Recap: Python file Handling Concept
	Using Python Modules
	Time Module
		Exercise 2-84: Import the time Module
			Explanation
	Sleep Method
		Exercise 2-85: Use the time.sleep() Function
			Explanation
		Exercise 2-86: Browse a Path Using the sys Module
			Explanation
		Exercise 2-87: Add a New Filepath Using the sys Module
			Explanation
		Exercise 2-88: Check Built-ins and sys.builtin_module
			Explanation
		Exercise 2-89: Use a Simple import sys Module in a try and except Exercise
			Explanation
		Exercise 2-90: Understand Lambdas by Making a Calculator
			Explanation
		Recap: Module Concepts
	Summary
Chapter 3: More Python Exercises
	Getting Ready for the Exercises
		Exercise 3-1: Concatenate a List and a Tuple into a Single List
			Explanation
		Exercise 3-2: Use Python as a Calculator
			Explanation
		Exercise 3-3: Do Some Basic String format() Exercises
			Explanation
		Exercise 3-4: Ask for a Username
			Explanation
		Exercise 3-5: Get a Username: Version 1
			Explanation
		Exercise 3-6: Get a Username: Version 2
			Explanation
		Exercise 3-7: Get a Username: Version 3
			Explanation
		Exercise 3-8: Add a Temporary Filepath, Import ex3_7.py as a Module, and Run the Script
			Explanation
		Exercise 3-9: Use Commas to Add Spaces Between Strings
			Explanation
		Exercise 3-10: Practice if; if and else; and if, elif, and else
			Explanation
		Exercise 3-11: Practice for ~ in range with end=‘'
			Explanation
		Exercise 3-12: Practice for ~ in range
			Explanation
		Exercise 3-13: Practice for line in ~
			Explanation
		Exercise 3-14: Use the split() Method
			Explanation
		Exercise 3-15: Practice with lstrip(), rstrip(), strip(), upper(), lower(), title(), and capitalize()
			Explanation
		Exercise 3-16: Create a file and read it four different ways
			Explanation
		Exercise 3-17: Read and Output Files for a More Detailed Understanding
			Explanation
		Exercise 3-18: Use the getpass() Module and User Input
			Explanation
		Exercise 3-19: Understand the Difference Between Encoding and Decoding
			Explanation
		Exercise 3-20: Handle CSV Files in Python with the csv Module
			Explanation
		Exercise 3-21: Output a CSV File
			Explanation
		Exercise 3-22: Find the Price of a Cisco ISR 4331 Router from a CSV File
			Explanation
		Exercise 3-23: Calculate the Total Cost of the Router Purchases: No Module
			Explanation
		Exercise 3-24: Calculate the Total Cost of the Router Purchases: Using the csv Module
			Explanation
		Exercise 3-25: Convert dd-mmm-yy and Calculate the Difference in Days and Then in Years
			Explanation
	Exploring the Python IDE Environment
	Summary
	Storytime 2: Machine vs. Human, The First Confrontation
Chapter 4: Introduction to VMware Workstation
	VMware Workstation at a Glance
		Type-1 vs. Type-2 Hypervisors
		VMware Workstation Pro for a Proof-of-Concept Lab
	Before Using VMware Workstation
		What’s Next on VMware Workstation 15 Pro?
		VMware Workstation 15 Pro User Console
	Basic Operations of VMware Workstation 15 Pro
		VMware Workstation Pro: Basic Operations
		VMware Workstation Menu
	Virtual Network Adapters
		Virtual Network Editor Overview
		Virtual Network Interface Description
		Revealing Each Virtual Network Interface Types
			Host-Only Networking
			Bridged Networking
			Network Address Translation Networking
	Summary
Chapter 5: Creating an Ubuntu Server Virtual Machine
	Downloading and Installing a Ubuntu Server 20 Image
	Downloading the Ubuntu Server 20.04 LTS Image
	Installing Ubuntu Server 20.04 LTS
	Logging In to a New Ubuntu Server 20 via SSH
	Customize Ubuntu Server
		Ubuntu VM Customization 1: Enable Root User SSH Login on Ubuntu Server 20.04
		Ubuntu VM Customization 2: Install a Desktop GUI and Other Packages
		Ubuntu VM Customization 3: Enable Root User GUI Access
	Taking a Snapshot of a Virtual Machine
	Cloning a Virtual Machine
	Summary
Chapter 6: Creating a CentOS 8 Server Virtual Machine
	Downloading and Installing a CentOS 8 Server Image
		Downloading the CentOS 8 Server Image
		Installing CentOS 8 Server
		Logging In to a New CentOS 8 Server via SSH
		Managing a Network Adapter on Linux
	Creating a GNS3 VM by Importing an .ova File
		Downloading and Installing the GNS3 VM from an .ova File
	Summary
	Storytime 3: The Origin of Hypervisors
Chapter 7: Linux Fundamentals
	Why Learn Linux?
	The Beginning of Linux
	Understanding the Linux Environment
	Understanding Linux Directories and File Formats
	vi vs. nano
		Introduction to vi
			Basics of vi
			Reopening a File in vi
			Copying and Pasting a Line in vi
			Undo Last in vi
			Searching for Text in vi
			Display the Line Number in vi
		Introduction to nano
			Installing nano
			Create/Open a File with nano
			Reopen a File with nano
			Cut (Delete) and Paste with nano
			String Search and Replacing String(s)
			Customize nano for Python Coding
	Linux Basic Administration
		Changing the Hostname
		Linux Basic File and Directory Commands
		Linux File and Directory Exercises
			Exercise 7-1
			Exercise 7-2
			Exercise 7-3
			Linux File and Directory Exercise 7-2
			Echo, Cat, More, and Less Command Exercise
			ls Command with Options
			Delete files and directories at once
			Create a Python Application, Make Your File Executable, Add a Shebang, and Run the Application
	Summary
Chapter 8: Linux Basic Administration
	Information on Linux: Kernel and Distribution Version
	Information on Linux: Use the netstat Command to Validate TCP/UDP Ports
	Installing TFTP, FTP, SFTP, and NTP Servers
		FTP Server Installation
		Installing the SFTP Server
		Installing the TFTP Server
		Installing the NTP Server
	Linux TCP/IP Troubleshooting Exercise
	Summary
	Storytime 4: Becoming a Savvy Linux Administrator, Perhaps Every IT Engineer’s Dream?
Chapter 9: Regular Expressions for Network Automation
	Why Regex?
		To re or Not to re
	Studying Regular Expressions Using Python
		Method 1: Using Notepad++
		Method 2: Using the Linux Shell
		Regular Expression Breakdown: [A-Z]{3}\d{4}[/]\w+
		Method 3: Using the Internet to Study Regular Expressions
	Regex Operation: The Basics
		Character Class ([])
		Dot (.): Single Character Match
		Asterisk (*): Repetition
		Plus (+): Repetition
		{m, n}: Repetition
			{m}
			{m, n}
			? (Question Mark: Repetition)
	Python’s re Module
		Python re String Methods
			re.match()
			re.search()
			re.findall()
			re.finditer()
		Match Object Method
	Compile Options
		re.DOTALL (re.S)
		re.IGNORECASE (re.I)
		re.MULTILINE (re.M)
		re.VERBOSE (re.X)
	\: Confusing Backslash Character
	Regular Expressions: A Little Revision Plus More
		More Metacharacters
			OR Operator (|)
			^ and $ (Anchors)
			\A and \Z
			\b and \B
			Grouping
			Regular Expression Named Groups
		Lookahead and Lookbehind Assertions
		Lookahead, Lookbehind, and Noncapturing group
		Practice More Lookarounds
		Lookaround Application Examples
	sub Method: Substituting Strings
		Substitute Strings Using sub
		Using sub and \g to Swap Positions
		Insert a Function in sub Method
	Summary
Chapter 10: GNS3 Basics
	GNS3 at a Glance
	Installing GNS3 for the First Time
		Downloading the GNS3 Installation File
	GNS3 Installation and Setup
		GNS3 Installation
		GNS3 Setup Procedures
	Getting Familiar with GNS3
		GNS3 Menus and GUI
		Gracefully Shutting Down GNS3 and GNS3 VM
		Starting GNS3 as an Administrator
	Using GNS3 for the First Time: Cisco IOS and Windows Lab
		Cisco IOS Software License and Downloading an Older Cisco IOS
		Decompressing Cisco IOS for GNS3 Use
			Decompressing Cisco IOS Using the Unpack.exe Method
			Decompressing Cisco IOS Using Dynamips Method (Optional)
	Installing Cisco IOS on the GNS3 VM
	Creating an IOS Lab Topology on GNS3 and Connecting to the Internet
	Installing the Microsoft Loopback Adapter
		Accessing GNS3 Network Devices Using MS Loopback
	Configuring the GNS3 IOS Router Using a Python Script from the Windows Host PC
	Cisco IOS and GNS3 Appliance Lab
		Importing and Installing the GNS3 Linux Appliance Server
		Manually Assigning IP Address to GNS3 Linux Appliance Server
		Using the GNS3 Appliance Linux’s Python to Manage R1
	Summary
Chapter 11: Cisco IOS Labs
	Cisco IOS and the Linux VM Lab
	Creating a New GNS3 Project for the Linux VM Lab
	Uploading and Downloading Files to the GNS3 IOS Router from Linux VMs (File Transfer Testing Lab)
	Copying (Cloning) a GNS3 Project
	Summary
Chapter 12: Building a Python Automation Lab Environment
	Cisco CML-PERSONAL Software License Information and Software Downloads
	Downloading the Cisco CML-PERSONAL IOSvL2 (Switch) Image
	Downloading the Cisco CML-PERSONAL IOSv (Router) Image and startup_config Files
	Installing the Cisco CML-PERSONAL L2 Switch and CML-PERSONAL L3 on GNS3
	Installing the Cisco CML-PERSONAL L2 Switch on GNS3
		Quick Communication Test on CML L2 Switch Integration on GNS3
	Installing the Cisco CML-PERSONAL L3 Router on GNS3
		Quick Communication Test on CML L3 Router Integration on GNS3
	Building a CML-PERSONAL Lab Topology
	Summary
Chapter 13: Python Network Automation Lab: Basic Telnet
	Python Network Automation: Telnet Labs
	Telnet Lab 1: Interactive Telnet Session to Cisco Devices on a Python Interpreter
	Telnet Lab 2: Configure a Single Switch with a Python Telnet Template
	Telnet Lab 3: Configure Random VLANs Using a for Loop
	Telnet Lab 4: Configure Random VLANs Using a while Loop
	Telnet Lab 5: Configure 100 VLANs Using the for ~ in range Loop Method
	Telnet Lab 6: Add a Privilege 3 User on Multiple Devices Using IP Addresses from an External File
	Telnet Lab 7: Taking Backups of running-config (or startup-config) to Local Server Storage
	Summary
Chapter 14: Python Network Automation Labs: SSH paramiko and netmiko
	Python Network Automation Labs Using the paramiko and netmiko Libraries
	Python SSH Labs: paramiko
	paramiko Lab 1: Configure the Clock and Time Zone of All Devices Interactively in the Python Interpreter
	paramiko Lab 2: Configuring an NTP Server on Cisco Devices Without User Interaction (NTP Lab)
	paramiko Lab 3: Create an Interactive paramiko SSH Script to Save Running Configurations to the TFTP Server
	Python SSH Labs: netmiko
	netmiko Lab 1: netmiko Uses a Dictionary for Device Information, Not a JSON Object
	netmiko Lab 2: Develop a Simple Port Scanner Using a Socket Module and Then Develop a nemiko Disable Telnet Script
	netmiko Lab 3: config compare
	Summary
Chapter 15: Python Network Automation Labs: cron and SNMPv3
	Cron and SNMPv3 Labs
	Cloning a GNS3 Project for the Next Lab
	Quick-Start to the Linux Scheduler, cron
		Ubuntu 20.04 LTS Task Scheduler: crontab
		CentOS8.1 Task Scheduler: crond
		Learn cron Job Definitions with Examples
	Using Python to Run an SNMPv3 Query
		Quick-Start Guide to SNMP
			Quick SNMP History
			SNMP Standard Operation
			SNMP Polling vs. Trap (Event Reporting) Method
			SNMP Versions
			Understanding the SNMP Protocol in the TCP/IP Stack
			About SNMP Message Types
			Understanding SNMP’s SMI, MIB, and OID
			SNMP Access Policy
			Synchronous vs. Asynchronous Communication While Using SNMP Traps
			SNMP-Related Python Libraries
			Understanding MIBs and OIDs and Browsing OIDs Directly
		Learn to Use SNMPwalk on a Linux Server
			Installing and Configuring SNMP Server on CentOS8
			Configuring Cisco Routers and Switches to Support SNMPv3 Using a Python Script
			SNMPwalk from Linux Server
		Borrowing Some Example Python SNMP Code
			SNMP Lab Source Code
			SNMPv3 Python Code to Query Cisco Device Information
			Using Python SNMP Code to Run a Query for an Interface Description
	Summary
Chapter 16: Python Network Automation Labs: Ansible, pyATS, Docker, and the Twilio API
	Python Network Automation Development Labs
	Quick-Start Guide to Ansible: virtualenv Lab 1
		Installing virtualenv and Getting Started with Ansible
	Quick-Start Guide to pyATS (Genie): VirtualEnv Lab 2
	Sendmail Lab Using an Imported Docker Image
		Docker Components and Account Registration
		Docker Installation
		Test-Driving Docker
		Docker Sendmail Python Lab
		Lab: Sendmail Email Notification script Development
	CPU Utilization Monitoring Lab: Send an SMS Message Using Twilio
		TWILIO Account Creation, Install Twilio Python Module and SMS Message Setup
		CPU Utilization Monitoring Lab with an SMS Message
	Summary
Chapter 17: Upgrading Multiple Cisco IOS XE Routers
	Practical Python Network Automation Lab: IOS XE Upgrade Lab
	Applying OOP Concepts to Your Network
	Flow Control and Controlling User Input: UID, PWD, and Information Collector
	Lab Preparation
		CSR 1000v IOS XE Software and Download
		Cisco CSR 1000v Installation on VMware Workstation
	Discussion of How an IOS (IOS-XE/XR) Is Upgraded on Cisco Devices
		Tasks Involved in a Cisco IOS Upgrade
	Summary
Chapter 18: Python Network Automation Lab: Cisco IOS Upgrade Mini Tools Development
	Cisco IOS Upgrade Application Development
	Part A: Pre-check Tools Development Connectivity Validation Tool
	Collect User’s Login Credentials and User Input
	Collect a New IOS Filename and MD5 Value from a CSV File
	Check the MD5 Value of the New IOS on the Server
	Check the Flash Size on Cisco Routers
	Make Backups of running-config, the Interface Status, and the Routing Table
	Part B: IOS Uploading and More Pre-check Tools Development
	IOS Uploading Tool
	Check the New IOS MD5 Value on the Cisco Device’s Flash
	Options to Stop or Reload the Routers
	Check the Reloading Device and Perform a Post-Reload Configuration Verification
	Summary
Chapter 19: Python Network Automation Labs: Combining and Completing the Cisco IOS Upgrade Application
	Creating a Single Python File
	Summary
	Final Words
Index