What is Terraform and How Does it Work?

Terraform users create and manage resources on the cloud and other services using their APIs. Service providers allow Terraform to work with almost any service or platform that has an accessible API. The global community of Terraform users has already partnered with over 1700 providers to manage several thousand types of services and resources. The Terraform Registry has the names of all publicly available service providers, which include AWS (Amazon Web Services), Microsoft Azure, Kubernetes, GCP (Google Cloud Platform), GitHub, Helm, DataDog and Splunk, among others. There are three stages of the core workflow Terraform follows:

1. Write: The user defines the resources that could be present across several cloud services and providers. For instance, you could create a configuration that deploys an app on VMs in a VPC (Virtual Private Cloud) network using security groups and a load balancer.
2. Plan: Based on the previous step, Terraform will create an implementation plan that describes the infrastructure it is going to update, create or destroy depending on the user’s configuration and existing IT infrastructure.
3. Apply: Once approved, Terraform will perform the suggested operations in the intended order, adhering to any resource dependencies. For instance, if a user wants to update a VPC’s properties and modify the number of VMs in the VPC, Terraform recreates the new VPC before the VMs are scaled up or down.

Features of Terraform:

Terraform functions by creating a graph-based database that gives operators deeper insight into any resource dependencies. Terraform also creates an execution plan that lets users see the steps it will take when changes are made or settings are applied. Terraform is made up of the following components:

1. A console that lets users observe functions like string, time, date, numeric, collections and encoding functions
2. A configuration language that will support interpolation and enable administrators to pass functions as a string and perform a series of operations
3. The functionality to translate HCL code into JSON
4. The Module Count feature that identifies the exact number of modules applied to existing infrastructure.

What Do Enterprises Use Terraform For?

1. External resource management: Terraform supports private and public cloud infrastructure along with SaaS deployments and network appliances.
2. Multi-cloud model deployments: Terraform has the native ability to support multi-cloud services which helps in increasing fault tolerance.
3. Multi-tier applications: It allows operators to easily scale resource collections up or down depending on the need.
4. Self-service clusters: A registry makes it easier for operators to identify prepackaged configurations they can use in as-is condition or modify to meet
   specific needs.
5. SDN (Software-defined networking): Terraform’s high readability helps network engineers easily codify configurations for software-defined networking.
6. Resource scheduler: A Terraform module can start and stop AWS resources and schedule Dockers containers using Kubernetes.
7. Disposable environments: A module helps in creating ad hoc, throwaway environments to test code before it goes into production.

Benefits of Choosing Terraform as a DevOps Tool:

• Terraform allows operators to define config/code infrastructure and enables users to change, rebuild and track infrastructure changes easily. It offers a high-level and comprehensive infrastructure description.
• Terraform is currently the only significant DevOps tool that is entirely platform agnostic and supportive of other services. While a handful of alternatives exist, they focus on single cloud providers.
• Terraform allows operators to implement various principles of coding such as automated test writing capabilities, using code with source control and others.
• Terraform is an open-source tool with an active, diverse and lively development community. Several people already use Terraform, which means it becomes easy to discover those who understand how to use the platform, extensions and the like.
• Terraform provides exceptional functionalities and speed. One of its key advantages is its plan command. It allows operators to see the changes they are set to make before applying them permanently. It also has a feature that lets users reuse their code. When it comes to the implementation of these changes, Terraform is more efficient than other similar DevOps tools such as CloudFormation.