Book Image

Azure Resource Manager Templates Quick Start Guide

By : Ritesh Modi
Book Image

Azure Resource Manager Templates Quick Start Guide

By: Ritesh Modi

Overview of this book

Azure Resource Manager (ARM) templates are declarations of Azure resources in the JSON format to provision and maintain them using infrastructure as code. This book gives practical solutions and examples for provisioning and managing various Azure services using ARM templates. The book starts with an understanding of infrastructure as code, a refresher on JSON, and then moves on to explain the fundamental concepts of ARM templates. Important concepts like iteration, conditional evaluation, security, usage of expressions, and functions will be covered in detail. You will use linked and nested templates to create modular ARM templates. You will see how to create multiple instances of the same resources, how to nest and link templates, and how to establish dependencies between them. You will also learn about implementing design patterns, secure template design, the unit testing of ARM templates, and adopting best practices. By the end of this book, you will understand the entire life cycle of ARM templates and their testing, and be able to author them for complex deployments.
Table of Contents (12 chapters)
Free Chapter
1
Section 1: ARM Template Foundational Skills
6
Section 2: ARM Template Advanced Concepts

Redefining resources in the same template

By now, you already know that it is not possible to define two resources in the same template having the same name. This means that if we define a resource in the template and later in the deployment execution we want to change any of its configurations, then it is not possible to do this.

The first question that might arise is why we cannot configure the resource with the end state, rather than reconfiguring. This is because there are situations, as we learned in the previous section, where it might not be possible to have all the values at the time of deployment; however, as template execution progresses and resources generate additional information, some of the resources might need reconfiguration.

Let's understand this concept with the help of an example. Imagine we are creating a virtual machine using templates on an existing...