Testing and evaluating a Terraform expression

When we write a Terraform configuration that contains variables and expressions or uses a built-in Terraform function, it’s sometimes difficult to predict the result of this Terraform configuration before running the apply command.

Fortunately, the Terraform CLI contains a feature that will allow us to evaluate Terraform code before applying changes.

In this recipe, we will see how to test and evaluate a Terraform expression.

Let’s get started!

Getting ready

To complete this recipe, we will use the following Terraform configuration that provisions Azure infrastructure:

https://github.com/PacktPublishing/Terraform-Cookbook-Second-Edition/tree/main/CHAP06/console

Here we use the azurerm provider, but this recipe can be applied for any Terraform configuration.

In this Terraform configuration, we use several Terraform variables and expressions such as:

locals {
  linux_web_app   = toset([for...