Infrastructure as Code: A Beginner's Guide
Tags: iac, terraform, cdk, pulumi
Published: 2023-08-19 07:06:49

The percentage of software companies that use IAC tools in the world is growing rapidly. In 2022, it was estimated that 55% of software companies were using IAC tools, and this number is expected to reach 75% by 2028.

**What is Infrastructure as Code?**

At its core, Infrastructure as Code (IAC) refers to the practice of managing and provisioning infrastructure resources through code and automation. In essence, it treats infrastructure components in the same way software developers handle their codebase. Instead of manually configuring servers, networks, and other resources, developers can define and manage these elements using code scripts and templates.

**The Significance of Infrastructure as Code**

The importance of adopting Infrastructure as Code (IAC) cannot be overstated, particularly in today's dynamic and competitive tech environment. Here are some key reasons why embracing IAC is essential:

**1. Consistency and Reproducibility:** Manual setups are prone to errors, and inconsistencies between different environments can lead to unexpected issues. IAC ensures that the infrastructure is defined in a consistent manner across all stages, from development to testing and production. This consistency facilitates easy replication of environments, reducing the risk of discrepancies that often lead to production outages.

**2. Version Control and Collaboration:** Treating infrastructure as code allows teams to leverage version control systems, just like they do for software code. This enables collaboration, tracking changes, and maintaining a historical record of modifications made to the infrastructure. As a result, teams can work together seamlessly, iterate efficiently, and revert to previous configurations if needed.

**3. Automation and Efficiency:** With IAC, repetitive tasks and configurations can be automated, freeing up valuable time for developers and operations teams. Automated provisioning not only accelerates the deployment process but also minimizes human errors that can arise from manual interventions.

**4. Scalability and Flexibility:** As applications grow and evolve, so does the need for scalable infrastructure. IAC allows teams to define scalability rules and configurations upfront, ensuring that the infrastructure can seamlessly adapt to changing demands without requiring substantial manual adjustments.

**5. Disaster Recovery and Redundancy:** IAC facilitates the creation of disaster recovery plans and redundancy setups by codifying backup configurations and failover mechanisms. This ensures that in the event of a failure, the recovery process can be initiated promptly and consistently.

**6. Documentation and Auditability:** Traditional setups often lack comprehensive documentation, making it challenging to understand the intricate details of the infrastructure. IAC inherently brings documentation through code comments and self-explanatory scripts, enhancing auditability and facilitating a deeper understanding of the infrastructure's architecture.


**Comparing AWS CDK, Pulumi, and Terraform: Making Informed Choices**

As organizations continue to embrace Infrastructure as Code (IAC) principles, the landscape of tools and frameworks to achieve this goal has expanded significantly. Among the prominent players in this arena are [AWS CDK](https://aws.amazon.com/cdk/), [Pulumi](https://www.pulumi.com/), and [Terraform](https://www.terraform.io/). Each of these tools brings its unique approach and features to the table, catering to the diverse needs of developers and operations teams. In this section, we will delve into a detailed comparison of these three tools, highlighting their strengths, weaknesses, and use cases.

**AWS CDK** is a framework for writing infrastructure code in JavaScript, TypeScript, Python, or Java. It uses the AWS CloudFormation service to deploy infrastructure. AWS CDK is a good choice for organizations that are already using AWS and want to use a tool that is tightly integrated with the AWS ecosystem.

**Pulumi** is a multi-cloud IAC tool that supports over 60 cloud providers, including AWS, Azure, and Google Cloud Platform. It uses a variety of programming languages, including Python, Go, C#, and JavaScript. Pulumi is a good choice for organizations that want to use a tool that is not tied to any particular cloud provider.

**Terraform** is an open-source IAC tool that supports over 200 cloud providers and infrastructure services. It uses a domain-specific language called HashiCorp Configuration Language (HCL) to define infrastructure. Terraform is a good choice for organizations that want a flexible and extensible IAC tool.

Here is a table that summarizes the key differences between AWS CDK, Pulumi, and Terraform:

|Feature|AWS CDK|Pulumi|Terraform|
|---|---|---|---|
|Programming languages|JavaScript, TypeScript, Python, Java|Python, Go, C#, JavaScript|HashiCorp Configuration Language (HCL)|
|Cloud providers|AWS|Over 60|Over 200|
|Extensibility|Good|Excellent|Excellent|
|Cost|Free|Free|Free|


**Similarities**

- All three tools can be used to automate the provisioning and configuration of infrastructure.
- All three tools can be used to manage changes to infrastructure.
- All three tools can be used to track changes to infrastructure.
- All three tools can be used to roll back to previous configurations.

**Differences**

- AWS CDK is tightly integrated with the AWS ecosystem.
- Pulumi supports over 60 cloud providers.
- Terraform is an open-source tool with a large community.
- AWS CDK uses JavaScript, TypeScript, Python, or Java.
- Pulumi uses Python, Go, C#, or JavaScript.
- Terraform uses HashiCorp Configuration Language (HCL).

**Getting Started: Tutorials for AWS CDK, Pulumi, and Terraform**

Embarking on your journey with AWS CDK, Pulumi, and Terraform can be exciting, but getting started might seem a bit overwhelming. Fear not, for each tool provides excellent resources to guide you through the initial steps. In this section, I'll provide you with brief tutorials to help you kickstart your experience with these powerful Infrastructure as Code tools.

**AWS CDK:**

1. **Installation:** To begin, ensure you have Node.js and npm installed. Then, install the AWS CDK CLI using the following command:
   
   ```
   npm install -g aws-cdk
   ```

2. **Create a CDK App:** Use the CDK CLI to create a new app scaffold:
   
   ```
   cdk init app --language=typescript
   ```

3. **Define Infrastructure:** Navigate to the newly created app directory and open the `lib` folder. You'll find a TypeScript file where you can define your infrastructure components using AWS CDK constructs.

```typescript

// Create an EC2 Instance

import { App, Stack, StackProps } from 'aws-cdk-lib';
import { AmazonLinuxImage, Instance, InstanceType, Vpc } from 'aws-cdk-lib/aws-ec2';

class EC2Stack extends Stack {
  constructor(scope: App, id: string, props?: StackProps) {
    super(scope, id, props);

    const vpc = new Vpc(this, 'MyVPC');

    new Instance(this, 'MyInstance', {
      instanceType: InstanceType.of(InstanceClass.BURSTABLE2, InstanceSize.MICRO),
      machineImage: new AmazonLinuxImage(),
      vpc,
    });
  }
}

const app = new App();
new EC2Stack(app, 'EC2Stack');

// Create an S3 bucket

import { App, Stack, StackProps } from 'aws-cdk-lib';
import { Bucket } from 'aws-cdk-lib/aws-s3';

class S3Stack extends Stack {
  constructor(scope: App, id: string, props?: StackProps) {
    super(scope, id, props);

    new Bucket(this, 'MyBucket', {
      versioned: true,
    });
  }
}

const app = new App();
new S3Stack(app, 'S3Stack');

```


5. **Deploy:** Run the following commands to deploy your infrastructure to AWS:
   
   ```
   cdk synth
   cdk deploy
   ```

**Pulumi:**

1. **Installation:** Install the Pulumi CLI by following the instructions for your platform: https://www.pulumi.com/docs/get-started/install/

2. **Create a New Project:** Use the Pulumi CLI to create a new project in your desired programming language:
   
   ```
   pulumi new
   ```

3. **Define Infrastructure:** Navigate to the project directory and open the main program file. You can now define your infrastructure resources using Pulumi's programming constructs.

```typescript

// Create an EC2 instance

import * as pulumi from '@pulumi/pulumi';
import * as aws from '@pulumi/aws';

const vpc = new aws.ec2.Vpc('my-vpc', {
  cidrBlock: '10.0.0.0/16',
});

const instance = new aws.ec2.Instance('my-instance', {
  instanceType: 't2.micro',
  ami: aws.ec2.getAmi({
    filters: [{
      name: 'name',
      values: ['amazon-linux-2'],
    }],
    mostRecent: true,
  }).id,
  subnetId: vpc.subnetIds[0],
});


// Create an S3 bucket

import * as pulumi from '@pulumi/pulumi';
import * as aws from '@pulumi/aws';

const bucket = new aws.s3.Bucket('my-bucket', {
  versioning: {
    enabled: true,
  },
});


```

5. **Provision Resources:** Run the following command to preview and deploy your resources:
   
   ```
   pulumi up
   ```

**Terraform:**

1. **Installation:** Install the Terraform CLI by following the instructions for your platform: https://learn.hashicorp.com/tutorials/terraform/install-cli

2. **Create a Configuration:** Create a new directory for your Terraform configuration files. Inside this directory, create a `.tf` file to define your infrastructure.

3. **Define Resources:** In your Terraform configuration file, define the resources you want to create using HashiCorp Configuration Language (HCL).

```hcl

# Create an EC2 instance.

provider "aws" {
  region = "us-east-1"
}

resource "aws_vpc" "my_vpc" {
  cidr_block = "10.0.0.0/16"
}

resource "aws_instance" "my_instance" {
  ami           = "ami-0c55b159cbfafe1f0"
  instance_type = "t2.micro"
  subnet_id     = aws_vpc.my_vpc.subnet_ids[0]
}


# Craete an S3 bucket

provider "aws" {
  region = "us-east-1"
}

resource "aws_s3_bucket" "my_bucket" {
  bucket = "my-unique-bucket-name"
  acl    = "private"

  versioning {
    enabled = true
  }
}

```

5. **Initialize and Apply:** Run the following commands to initialize and apply your Terraform configuration:
   
   ```
   terraform init
   terraform apply
   ```


**Conclusion: Choosing the Right Tool**

As you've experienced, AWS CDK, Pulumi, and Terraform each offer distinct approaches to Infrastructure as Code, catering to various preferences and project requirements. AWS CDK stands out for its programming language familiarity and AWS integration. Pulumi excels in multi-cloud support and fine-grained control. Terraform's declarative syntax and thriving community make it a solid choice for many.

To make an informed decision, consider the complexity of your project, your team's expertise, and the cloud providers you intend to work with. Each tool has its strengths and can be a valuable asset in your IAC journey. By mastering the nuances of these tools, you're poised to streamline infrastructure provisioning, enhance collaboration, and create more robust and scalable applications.

If you're eager to delve deeper into the world of AWS CDK and learn about practical insights from real-world experiences, I invite you to subscribe to my newsletter (I won't spam, I promise!). In an upcoming series, I'll unravel how [Cogoport](https://www.cogoport.com) has harnessed the power of AWS CDK to sculpt its infrastructure, navigating challenges and triumphs along the way. It's a chance to gain firsthand knowledge and discover the art of shaping digital landscapes.

Originally published at [https://aniljaiswal.com](https://aniljaiswal.com/blog/introduction-to-iac-using-cdk-pulumi-and-terraform?utm_source=dev-to&utm_medium=post&utm_campaign=IAC-Article).