OVERVIEW OF TERRAFORM MODULES:

Terraform Modules are reusable and self-contained configurations that can be used to create multiple instances of infrastructure resources. Modules enable you to encapsulate a set of resources with their associated configuration into a single reusable component. This promotes code reusability, consistency, and easier collaboration across different projects and environments.

BENEFITS OF TERRAFORM MODULES:

  • Reusability: Modules allow you to define infrastructure components once and reuse them across multiple projects or environments. This reduces duplication of code and promotes consistency in your infrastructure configurations.
  • Abstraction: Modules provide an abstraction layer that hides the complexity of resource configurations. By encapsulating resources and their dependencies, modules make it easier to manage and understand your infrastructure code.
  • Collaboration: Modules enable collaboration among team members by providing a standardized way to define and share infrastructure components. Each team member can develop and maintain separate modules, which can be combined to create complex infrastructures.
  • Versioning: Modules can be versioned and shared through version control systems or Terraform module registries. This allows you to track changes, manage dependencies, and ensure reproducibility across different projects or environments.

EXAMPLE USAGE:

Let’s consider an example where you have a Terraform module for creating an Amazon VPC and its associated resources. Here’s how you can use modules:

1. Defining a Module:

Create a module directory with a `main.tf` file that defines the resources and configuration for the VPC module. For example:

# module/vpc/main.tf
variable “vpc_cidr_block” {
  type    = string
  default = “10.0.0.0/16“
}
resource “aws_vpc” “main” {
  cidr_block = var.vpc_cidr_block
  # other VPC configuration…
}
 
# Define other resources such as subnets, route tables, etc.

 

This module defines an AWS VPC with a customizable CIDR block.

2. Using a Module:

In your main Terraform configuration, you can use the module by referencing its source and providing values for any input variables. For example:

# main.tf
module “my_vpc” {
  source          = “./module/vpc“
  vpc_cidr_block  = “10.0.0.0/16“
}

 

This configuration uses the VPC module located in the “./module/vpc” directory and sets the `vpc_cidr_block` variable to “10.0.0.0/16“.

3. Applying Changes:

To apply the changes and create the VPC defined in the module, run the `terraform apply` command in the main configuration directory:

$ terraform apply

 

This command applies the changes defined in the main configuration, including the resources defined in the VPC module.

4. Reusing Modules:

You can reuse the same module in different projects or environments by referencing its source from a different main configuration file. For example, you can create a separate main configuration for a different project and reuse the VPC module:

$ terraform workspace select staging

 

This configuration uses the same VPC module but sets a different CIDR block.

FINAL THOUGHTS:

By utilizing Terraform’s for_each function, you can to iterate over a collection of values or objects and dynamically create multiple instances of a resource or module based on those iterations.  It will add consistency, scalability, and manageability to your Infrastructure as code.  To learn more about what Terraform has to offer, follow this link to get in contact with one of our experts.

We’ve helped a variety of organizations get started the right way on their journey into infrastructure as code.

For more technical how-to’s click here.