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

Specifying parameter attributes


In this section, we will discuss the parameter attributes and how to set them. The attributes falling under this category define the different attributes of the parameter itself. Let's take a closer look at the most useful and common options available to define parameter attributes and their uses:

  • Mandatory argument: This argument indicates that this particular parameter is compulsory, otherwise it is optional. For example, if I am writing a function to connect to a vCenter server and doing some work and I want the vCenter name to be provided at runtime, then the following code makes sure that the cmdlet call will fail without the $VCName parameter:

    Param (
      [parameter(Mandatory=$true)]
      [String]$VCName
    )
  • Position argument: We define the positional argument to specify which value will be assigned to which parameter by the position of the values at runtime, without the need to specify the parameter name. PowerShell will understand which parameter the value...