Terraform is the world’s most popular open-source tool for Infrastructure-as-Code (IaC) configuration and management, and this dominance will likely remain the same in the foreseeable future. Terraform continues to gain new users as it shows palpable advantages and benefits for IaC management. Unsurprisingly, Terraform has also evolved over the years. Recently, it went through user interface changes and incorporated AI in its testing function.

However, before exploring the new features, it is important to take full advantage of the already existing important functions in Terraform. Terraform Modules, in particular, can provide multiple advantages but IaC administrators may not be optimally using them. These modules can maximize workflow efficiency and streamline DevOps practices, so there’s no reason not to get better acquainted with them and put them to practical use.

The nature of Terraform modules

Terraform modules are essentially a group of resources contained in Terraform files in the same directory. Virtually all Terraform users have stumbled upon these modules because they are the same modules they are dealing with if they have a configuration directory similar to what is shown below:

│ main.tf

│ outputs.tf

│ terraform.tf

│ variables.tf

This configuration directory shows the root module, and it can include other objects such as data sources, resources, input variables, and output variables. The root module may also have a child module that lists the same kinds of objects. Modules present common patterns and logical classifications of resources to be deployed across different configurations. It’s like putting the grouping of resources with common patterns in deployment into code.

Aside from grouping resources based on shared patterns, Terraform modules also support reusability, wherein resources are packaged in a configuration that can be used again and again. Additionally, it enables the sharing of standardized configurations and the concept of "don't repeat yourself" (DRY) programming.

Making code reusable and easy to maintain

Reusability is a key requirement, which goes side by side with Terraform modules as they enable the encapsulation of infrastructure components and the creation of self-contained and reusable units of code. This provides a workflow optimization advantage by preventing instances of duplicate or redundant code across different projects. It also results in consistency and development time reduction.

Complementing reusability is the advantage of easy maintainability. Terraform modules are isolated from the changes made to specific components of the infrastructure. As such, individual modules can be updated individually without affecting the overall codebase. This also makes it easier to conduct debugging. Troubleshooting modular code is considerably easier than handling errors and bugs in conventional code. Problems can be identified faster and resolved in a timely manner.

Setting customizable and adaptable parameters

Terraform modules support parameterization, enabling the customization of module behavior to suit different use cases. Modules can be set with specific parameters to respond to specific inputs and adapt to different requirements. This makes it possible for modules to be reusable for different contexts without the need to change them. This is important in the deployment of infrastructure with slight variations.

This parameterization ensures adaptability to different requirements and scenarios. It reduces or even eliminates the need to make changes to the module code to account for the slight variations in the infrastructure. In other words, teams can use the same module with different configurations.

Scaling with composable architecture and hierarchical organization

In addition to adaptability and customization, Terraform modules provide the benefit of scalability. They enable the building of a composable architecture. Smaller modules can be combined to create a bigger and more complex system, enabling the scaling of infrastructure to meet the growing and evolving needs of an organization.

On the other hand, Terraform modules are compatible with the concept of hierarchical organization. This is particularly useful for DevOps teams as it enables the separate management of different layers of the infrastructure. This hierarchical organization supports the scaling of specific components without having to worry about the possibility of modular changes impacting the entire infrastructure.

Centralizing management and versioning through remote modules

One highly valuable feature of Terraform modules is remote operation. Modules can be remotely stored in module registries or version control systems, which enables the centralized management of multiple modular components. This makes it easy for the DevOps process to share and update modules across multiple projects and teams.

To emphasize, Terraform modules can be stored in version control systems, which means that versioning is inherently easy for them. DevOps teams can easily track changes in their code and roll back to previous versions whenever necessary. This ensures efficiency in version handling and any troubleshooting that may emerge during deployments.

Integrating with continuous integration and delivery pipelines

Another benefit of Terraform modules is automation through the integration of Terraform modules into continuous integration and continuous delivery (CI/CD) pipelines. This integration enables the automation of the testing and deployment of infrastructure code changes. It also provides the assurance that all changes are consistently deployed, which significantly diminishes the possibility of errors.

Additionally, the CI/CD integration results in efficient workflows because it results in predictability. The CI/CD pipeline automation ensures that repetitive tasks are properly undertaken, especially in the areas of testing, validation, and deployment. This also provides the added benefit of accelerating the delivery of infrastructure changes.

Collaborating to improve workflows and streamline DevOps

It’s also worth pointing out that Terraform modules are helpful in enabling collaboration. Back in 2018, HashiCorp announced three core elements that comprise the Terraform collaboration experience, and the ability to share reusable Terraform modules through the module registry was one of them. Terraform modules come with well-defined interfaces that make it easy for different teams to work in concert but independently.

Terraform modules act as self-contained units that are easy to comprehend. Teams should generally be able to understand and collaborate on specific components without in-depth knowledge on the overall infrastructure. This results in development workflow agility and empowers both autonomous activity and collaborative efforts at the same time.

In conclusion

Terraform modules are an important feature of the Terraform IaC tool and should be maximized to achieve efficient workflows and streamlined DevOps. They enable the reusability of code components and ensure efficient code management while also providing other notable advantages such as automation, parameterization, and scalability. Regardless of an organization’s size or nature of operation, it is advisable to get properly acquainted with Terraform modules and make the most of them to unlock the full potential of infrastructure-as-code adoption.