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

Variables

Variables are very similar to parameters in that they help to keep templates generic and maintainable. Modifying the value of a variable at a single place helps to update its value in all the places it is referenced from. However, there are a few notable differences between variables and parameters.

variables are defined and assigned values within the template itself, while values for parameters come from external sources. variables do not have data types declared explicitly, they do not have any facility to apply constraints or add description.

Possibly the best use case for variables is any data that is used multiple times within template should be replaced by variables. variables are name-value pairs where the value can be as simple as a literal string or a complex JSON object or array.

Variables are defined within the variables section of template. The next code...