Get started with IAC and Terraform

If you're new to the world of IT infrastructure, you may have heard the term "Infrastructure as Code" or "IAC" tossed around, but may not know exactly what it means. Essentially, IAC is an approach to managing IT infrastructure through the use of code. It's an important concept in modern IT infrastructure as it provides faster and more efficient infrastructure deployment, improved scalability, and better infrastructure management, among other benefits.

In this blog post, we'll dive deeper into IAC, explore its key features and capabilities, and take a closer look at one of the most popular IAC tools - Terraform.

Defining IAC

Infrastructure as Code (IAC) is an approach to managing IT infrastructure through the use of code. Essentially, it involves writing code that defines and automates the deployment and management of infrastructure resources, such as virtual machines, databases, and networks.

Why IAC is important in modern IT infrastructure

IAC provides numerous benefits, including faster and more efficient infrastructure deployment, improved scalability, and better infrastructure management. It also promotes consistency and eliminates manual errors, which can be costly and time-consuming to fix. Additionally, IAC makes it easier to track changes to infrastructure and roll back changes if necessary.

Key features and capabilities of each tool

There are many IAC tools available, including Terraform, Ansible, and Chef. Each tool has its own unique features and capabilities.

Declarative and Imperative Approaches in Terraform

Terraform uses a declarative approach to infrastructure management, meaning that the code describes the desired state of the infrastructure, and Terraform is responsible for creating and maintaining that state. In contrast, an imperative approach involves specifying the exact steps needed to achieve the desired state. Declarative approaches are generally more flexible and easier to use, as they allow for easier automation and standardization of infrastructure management.

Comparison of IAC tools based on their working approach

While all IAC tools automate infrastructure management, they differ in their approach. Some tools use a declarative approach, which focuses on defining the desired state of infrastructure resources, while others use an imperative approach, which involves defining the steps required to achieve the desired state.

The distinction between the two phases in IAC - Initial setup and maintenance

IAC is typically divided into two phases - initial setup and maintenance.

The initial setup process for Infrastructure as Code (IAC) and Terraform involves writing the code that defines the infrastructure resources and automates their deployment. This step is crucial because it sets the foundation for the entire infrastructure provisioning process. The code defines the desired state of the infrastructure resources, which Terraform will then use to create and manage those resources.

Maintenance involves updating the code to reflect changes in the infrastructure over time. In other words, as your infrastructure needs to change, you need to modify your IAC code to reflect those changes.

Overall, the maintenance phase in IAC is critical to ensuring that your infrastructure remains up-to-date and meets the changing needs of your business.

Now, let's take a closer look at Terraform.

Understanding infrastructure provisioning

Infrastructure provisioning involves the creation of infrastructure resources like virtual machines, networks, and storage. Terraform simplifies this process by allowing users to define infrastructure resources in a simple and consistent manner.

Terraform use cases and applications

Terraform can be used in a variety of scenarios, including cloud infrastructure provisioning, on-premises infrastructure provisioning, and multi-cloud deployments. It can also be used for continuous deployment and testing.

How Terraform Works

Terraform works by defining and managing infrastructure resources through code. This code is written in HashiCorp Configuration Language (HCL) and describes the desired state of the infrastructure.

Understanding the Architecture and Components

Terraform architecture consists of three main components:

1. Terraform Core: This is the core component of Terraform, responsible for parsing the configuration files, building the resource graph, and executing the plan to create, update or delete resources. It interacts with the provider plugins to manage the resources.
2. Provider Plugins: Terraform supports a wide range of cloud providers like AWS, Azure, and GCP. Each provider has its own plugin that Terraform uses to communicate with the provider APIs to create, update, and delete resources.
3. State Storage: Terraform uses state files to keep track of the current state of the resources it manages. The state files are JSON files that store the mapping between the resources in the configuration files and the real resources in the cloud provider.

Terraform Example Configuration File

Let's take a look at a simple Terraform configuration file that creates an AWS EC2 instance.

provider "aws" {
  region = "us-west-2"
}

resource "aws_instance" "example" {
  ami           = "ami-0c55b159cbfafe1f0"
  instance_type = "t2.micro"

  tags = {
    Name = "example-instance"
  }
}

This configuration file consists of two sections.

1. Provider Block: The provider block defines the cloud provider and its configuration. In this example, we're using AWS as our cloud provider, and specifying the region as "us-west-2".
2. Resource Block: The resource block defines the AWS instance we want to create and its configuration. We're specifying the Amazon Machine Image (AMI) ID as "ami-0c55b159cbfafe1f0", the instance type as "t2.micro", and assigning a tag to the instance with the name "example-instance".

Terraform Basic Commands

Here are some basic Terraform commands and their usage:

1. terraform init - initializes a new Terraform working directory and downloads any necessary plugins.
2. terraform plan - shows a preview of changes that Terraform will make to the infrastructure.
3. terraform apply - creates, modifies, or deletes resources based on the current Terraform configuration.
4. terraform destroy - destroys all resources created by Terraform.
5. terraform state - provides information about the Terraform state, including which resources are currently managed.

Step-by-Step Guide to Using Terraform Basic Commands

To get started with Terraform, follow these steps:

1. Install Terraform on your local machine.
2. Write your Terraform configuration file in HCL.
3. Initialize your working directory using the terraform init command.
4. Use the terraform plan command to preview changes to the infrastructure.
5. Use the terraform apply command to create, modify, or delete resources.
6. Use the terraform destroy command to remove all resources created by Terraform.

Summary

In conclusion, Infrastructure as Code (IAC) is an approach to managing IT infrastructure through code, which provides numerous benefits such as faster and more efficient infrastructure deployment, improved scalability, better infrastructure management, consistency, and eliminating manual errors.

There are many IAC tools available, including Terraform, Ansible, and Chef, each with its own unique features and capabilities. IAC is typically divided into two phases - initial setup and maintenance. Terraform is an open-source IAC tool that simplifies infrastructure provisioning by allowing users to define infrastructure resources in a simple and consistent manner.

Terraform can be used in a variety of scenarios, including cloud infrastructure provisioning, on-premises infrastructure provisioning, and multi-cloud deployments, making it a versatile tool for infrastructure management.

Ultimately, IAC tools like Terraform provide organizations with a more efficient and scalable approach to infrastructure management, enabling them to meet the changing needs of their business while reducing the risk of human error.

🔗 Want to deepen your knowledge of Terraform? check my post on How to provision a Kubernetes container engine with Terraform on Oracle Cloud Infrastructure (OCI).

Hi! I am Safoor Safdar a Senior SRE. Read More. Don't hesitate to reach out! You can find me on Linkedin, or simply drop me an email at me@safoorsafdar.com