The term “infrastructure” has many uses and meanings. However, when we talk about infrastructure in the context of Information Technology, we mean the combination of hardware, software, facilities, services, and networks used to support, control, develop, deliver, monitor, or test IT services.

In our IT-dominated world, the proper infrastructure can potentially be all that stands between a successful, smooth-running organization and another failed business. But the rise of the cloud has added a new dimension to the IT world, bringing new challenges, functionalities, and opportunities.

Infrastructure as Code provides users with a new way to conduct IT operations. However, recent developments need tools to make things run smoother.

Today, we are looking to answer “What is Terraform,” a powerful and versatile IaC tool. We will explore what Terraform is, what it does, why it's essential, and how to use it. Let’s get things started by defining Terraform.

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What Is Terraform?

Terraformers in science fiction stories are experts who can reshape an otherwise desolate, lifeless planet into a life-sustaining world suitable for colonization.

According to the product website, Terraform is “…an infrastructure as code (IaC) tool that allows you to build, change, and version infrastructure safely and efficiently. This includes low-level components such as compute instances, storage, and networking, as well as high-level components such as DNS entries, SaaS features, etc. Terraform can manage both existing service providers and custom in-house solutions.”

It’s tough to run and oversee infrastructures. Many infrastructures are loaded with countless configurations and components and are sometimes scattered across multiple cloud vendors. And to complicate matters further, some teams may need a particular variation of the existing infrastructure.

Terraform is a tool for users to help build, change, and version infrastructure safely and efficiently. It's ideal for IT Professionals, Cloud Engineers, DevOps Engineers, and Developers and a perfect asset for any candidate to understand when they interview for one of those job titles.

What Is Terraform: Key Features

Here are Terraform’s main features:

  • Infrastructure as Code: IT professionals use Terraform’s high-level configuration language (HCL) to describe the infrastructure in human-readable, declarative configuration files. Terraform lets you create a blueprint, a template that you can version, share, and re-use.
  • Execution Plans: Once the user describes the infrastructure, Terraform creates an execution plan. This plan describes what Terraform will do and asks for your approval before initiating any infrastructure changes. This step lets you review changes before Terraform does anything to the infrastructure, including creating, updating, or deleting it.
  • Resource Graph: Terraform generates a resource graph, creating or altering non-dependent resources in parallel. This graph enables Terraform to build resources as efficiently as possible while giving the users greater insight into their infrastructure.
  • Change Automation: Terraform can implement complex changesets to the infrastructure with virtually no human interaction. When users update the configuration files, Terraform figures out what has changed and creates an incremental execution plan that respects the dependencies.

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What Is Terraform and Why Is It Important?

There are three reasons why Terraform is an essential tool for developers and is superior to other IaC resources.

  • It’s open-source: Terraform has many contributors who regularly build add-ons for the platform. So, regardless of the platform you’re using, you will easily find support, extensions, and plugins. The open-source environment also encourages new benefits and improvements, so the tool is constantly and rapidly evolving.
  • It’s platform-agnostic: Platform-agnostic means that the product is not limited to one platform or operating system. In Terraform’s case, it means you can use it with any cloud service provider, whereas with most other IaC tools, you are limited to a single platform.
  • It provisions an immutable infrastructure: Most other Infrastructure as Code tools generate a mutable infrastructure, meaning it changes to accommodate things like new storage servers or middleware upgrades. Unfortunately, mutable infrastructures are susceptible to configuration drift. Configuration drift occurs when the actual provisioning of various servers or other infrastructure elements "drift" away from the original configuration under the weight of accumulated changes. In Terraform's case, the infrastructure is immutable, meaning that the current configuration is replaced with a new one that factors in the changes, then the infrastructure is reprovisioned. As a bonus, the previous configurations can be saved as older versions if you need to perform a rollback, much like how you can restore a laptop's configuration to an earlier saved version.

These three reasons show why Terraform is a valuable DevOps resource.

Why Infrastructure as Code?

Red Hat defines infrastructure as Code (called IaC for short) as "… the managing and provisioning of infrastructure through code instead of through manual processes." When using IaC, users create configuration files that contain the infrastructure specifications, making it easier to edit and distribute configurations. Infrastructure as Code also ensures that you consistently provision the same environment each time. In addition, IaC helps make configuration management easier by codifying and documenting configuration specifications and helps avoid undocumented, ad-hoc configuration changes.

Thanks to using IaC for infrastructure provisioning automation, developers don't have to manually manage operating systems, storage, servers, and other infrastructure components each time they deploy or develop an application.

Terraform’s Core Elements & Providers

Terraform consists of two chief components: Terraform Core and Terraform Plugins.

  • Terraform Core: This component monitors the reading and interpolation of configuration files, resource plan executions, state management features, and resource graphs. Terraform Core is made up of compiled binaries written in the Go language.
  • Terraform Plugin: The plugins define resources for specific services, including initializing the libraries used to make API calls and authenticating infrastructure providers. As is the case with Terraform Core, Terraform Plugins are written in the Go programming language as executable binaries for either a specific server or as a provisioner.

Providers are plugins that implement the resource types. They contain all the necessary code to authenticate and connect to a specific service, usually from a public cloud provider, on the user’s behalf. Terraform supports 100 cloud providers, including Alibaba Cloud, AWS, Azure, Google Cloud Platform, Kubernetes, and the Oracle Cloud Infrastructure.

The provider enables interfacing with the specific API, SaaS providers, and cloud providers and exposes the defined resources. No matter which provider is being used, resources are typically defined using the HashiCorp Configuration Language (HCL).

You can find the right providers for any cloud platforms and services you use and add them to your configuration. After adding the providers, you can use their resources to provide infrastructure. Fortunately, providers are available for almost every major cloud provider, SaaS offering, and a lot more. In addition, the providers are developed or supported by the overall Terraform community or individual organizations. If you have any further questions about providers, refer to the Terraform documentation for a detailed list.

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Modules: Package and Reuse Code

Terraform allows developers to package and re-use common code with modules, comparable to methods or functions in programming or scripting languages. Modules also make projects easier by boosting readability and organizing infrastructure in logical blocks. In addition, modules can be easily shared between teams and sourced into other Terraform projects.

Modules are great for cutting down on tedious tasks like copying and pasting different code sections while changing only a tiny handful of parameters. Thus, modules are typically used as an easier means of creating and managing many resources simultaneously.

State Management

State management is a vital piece of any long-term Terraform project. The state file keeps track of all environmental changes and can also serve as a source of data that can eventually be imported into other Terraform projects. The state file is stored on the filesystem by default. However, it is essential for users to keep the state file safe, secure, current, and backed up. As a result, the state file needs to reside in highly available object storage. Teams can leverage this remote storage, safely sharing and interacting with a single state that is always kept updated and current.

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Does DevOps Interest You?

We’ve sometimes mentioned DevOps while answering the question “what is Terraform,” and that’s because the IaC tool is such an excellent fit for that methodology. DevOps continues to be a popular app design philosophy, and the field has many potential positions open for the right candidate.

Simplilearn offers a Post Graduate Program in DevOps that will help you master the intricacies of this popular and versatile design methodology. The course, designed in collaboration with Caltech CTME, prepares you for a career in DevOps, bridging the gap between software developers and operations teams. This certification training will help you master the art and science of improving your entire team's development and operational activities. In addition, this course will help you build expertise via hands-on projects in continuous deployment, using configuration management tools such as Puppet, SaltStack, and Ansible.

Additionally, Simplilearn has a great selection of additional DevOps-related courses to choose from, including Certified Kubernetes Administrator, CI/CD Pipeline with Jenkins, and a Docker Certified Associate (DCA) Certification Training Course.

According to Glassdoor, DevOps Engineers in the United States earn an annual average of $105,107. Furthermore, Glassdoor reports that DevOps Engineers in India can bring in an average yearly salary of ₹655,000.

So why wait? Check out Simplilearn today and get started in an exciting new career in DevOps!

About the Author

John TerraJohn Terra

John Terra lives in Nashua, New Hampshire and has been writing freelance since 1986. Besides his volume of work in the gaming industry, he has written articles for Inc.Magazine and Computer Shopper, as well as software reviews for ZDNet. More recently, he has done extensive work as a professional blogger. His hobbies include running, gaming, and consuming craft beers. His refrigerator is Wi-Fi compliant.

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