Book Image

Mastering PowerCLI

By : Sajal Debnath
Book Image

Mastering PowerCLI

By: Sajal Debnath

Overview of this book

Have you ever wished that every morning you could automatically get a report with all the relevant information about your datacenter in exactly the same format you want? Or whether you could automate that boring, exhausting task? What if some crucial task needs to be performed on a regular basis without any error? PowerCLI scripts do all that and much more for VMware environments. It is built on top of the popular Windows PowerShell, with which you can automate server tasks and reduce manual input, allowing you to focus on more important tasks. This book will help you to achieve your goals by starting with a short refresher on PowerShell and PowerCLI and then covering the nuances of advanced functions and reusable scripts. Next you will learn how to build a vSphere-powered virtualized datacenter using PowerCLI while managing different aspects of the environment including automated installation, network, and storage. You will then manage different logical constructs of vSphere environment and different aspects of a virtual machine. Later, you will implement the best practices for a security implementation in vSphere Environment through PowerCLI before discovering how to manage other VMware environments such as SRM, vCloud Director and vCloud Air through PowerCLI. You will also learn to manage vSphere environments using advanced properties by accessing vSphere API and REST APIs through PowerCLI. Finally, you will build a Windows GUI application using PowerShell followed by a couple of sample scripts for reporting and managing vSphere environments with detailed explanations of the scripts. By the end of the book, you will have the required in-depth knowledge to master the art of PowerCLI scripting.
Table of Contents (21 chapters)
Mastering PowerCLI
Credits
Foreword
About the Author
Acknowledgment
About the Reviewers
www.PacktPub.com
Preface
Index

Chapter 2. Reusable Advanced Functions and Scripts

In the first chapter, we revisited PowerShell and PowerCLI basics. Then, we discussed how we could use the GitHub version to control our work and collaborate with others to work on the same project. We also learned how to use Pester to do unit testing on our work. In this chapter, we are going to cover advanced functions and their implementations in PowerShell. Specifically, we are going to talk about the following topics:

  • Specifying function attributes

  • Specifying parameter attributes

  • Using parameter validation attributes

  • Using dynamic parameters

  • PowerShell help files

  • Creating comment-based help

  • Error handling in PowerShell

Before we start discussing advanced functions, let's take a look at normal functions. If you type Get-Help About_Functions in PowerShell, you can get the details of functions. The description says a function is a list of Windows PowerShell statements that has a name that you can assign. When you run a function, you type the function...