How do you declare a variable in a Terraform configuration?

In Terraform, variables are declared using a specific syntax within a variable block. This is done by utilizing the structure variable "<name>" {} where <name> is replaced with the variable's name. This block can include specifications such as data types, default values, descriptions, and validation rules. This approach not only establishes the variable but also allows you to provide additional metadata around its usage, thereby enhancing the clarity and documentation of your Terraform configurations.

For example, you could declare a variable for an AWS region as follows:

variable "region" {

description = "The AWS region to deploy resources into"

default     = "us-west-2"

}

This structure is essential for defining configuration parameters that can be reused throughout the Terraform files, promoting modularity and adaptability in your infrastructure definitions.

Other methods mentioned do not align with the standard syntax for declaring variables in Terraform, making the utilization of the variable block the most appropriate method to establish and manage these important configuration values.