Book Image

Terraform Cookbook

By : Mikael Krief
Book Image

Terraform Cookbook

By: Mikael Krief

Overview of this book

HashiCorp Configuration Language (HCL) has changed how we define and provision a data center infrastructure with the launch of Terraform—one of the most popular and powerful products for building Infrastructure as Code. This practical guide will show you how to leverage HashiCorp's Terraform tool to manage a complex infrastructure with ease. Starting with recipes for setting up the environment, this book will gradually guide you in configuring, provisioning, collaborating, and building a multi-environment architecture. Unlike other books, you’ll also be able to explore recipes with real-world examples to provision your Azure infrastructure with Terraform. Once you’ve covered topics such as Azure Template, Azure CLI, Terraform configuration, and Terragrunt, you’ll delve into manual and automated testing with Terraform configurations. The next set of chapters will show you how to manage a balanced and efficient infrastructure and create reusable infrastructure with Terraform modules. Finally, you’ll explore the latest DevOps trends such as continuous integration and continuous delivery (CI/CD) and zero-downtime deployments. By the end of this book, you’ll have developed the skills you need to get the most value out of Terraform and manage your infrastructure effectively.
Table of Contents (10 chapters)

Writing conditional expressions

When writing the Terraform configuration, we may need to make the code more dynamic by integrating various conditions. In this recipe, we will discuss an example of an equal condition operation.

Getting ready

For this recipe, we will use the Terraform configuration we wrote in the previous recipe, whose code is available at https://github.com/PacktPublishing/Terraform-Cookbook/tree/master/CHAP02/fct.

We will complete this code by adding a condition to the name of the Resource Group. This condition is as follows: if the name of the environment is equal to Production, then the name of the Resource Group will be in the form RG-<APP NAME>; otherwise, the name of the Resource Group will be in the form RG-<APP NAME>-<ENVIRONMENT NAME>.

How to do it…

In the Terraform configuration of the main.tf file, modify the code of the Resource Group, as follows:

resource "azurerm_resource_group" "rg-app" {
name = var.environment == "Production" ? upper(format("RG-%s",var.app-name)) : upper(format("RG-%s-%s",var.app-name,var.environment))
location = "westeurope"
}

How it works…

Here, we added the following condition:

condition ? true assert : false assert

The result of executing Terraform commands on this code if the environment variable is equal to production can be seen in the following screenshot:

If the environment variable is not equal to production, we'll get the following output:

See also

Documentation on the various conditions of Terraform can be found at https://www.terraform.io/docs/configuration/expressions.html#conditional-expressions.