Pulumi vs Terraform for AWS

In my earlier projects, Terraform was my go-to for infrastructure as code. I loved how straightforward it was—just write your HCL, terraform init, terraform plan, terraform apply, and watch your infrastructure spring to life. I built everything from multi-region AWS setups to complex hybrid architectures with it. It felt like second nature, almost like a comforting ritual. But then, a new project threw me a curveball: Pulumi.

I remember my first thought: “Why mess with a good thing?” But curiosity got the better of me. Pulumi wasn’t just a new tool—it was a new way of thinking. Suddenly, I was writing TypeScript to define my infrastructure, using loops and conditionals like it was any other coding project. It was a bit like switching from driving a stick shift to an automatic—familiar, but different enough to make you second-guess everything.

One particular moment sticks out: I needed to build a complex multi-environment setup, something that would’ve taken endless Terraform modules and variables. In Pulumi, I wrote a few functions, and suddenly, everything felt modular and reusable in a way I hadn’t experienced before. It was like finding a secret feature in a game you’ve played for years.

At first, I missed Terraform’s simplicity, but as I got deeper into Pulumi, I started to enjoy the flexibility it offered. It wasn’t just about provisioning resources; it was about coding with the freedom to do things differently. Looking back, learning Pulumi wasn’t just about picking up a new tool—it was about embracing a new mindset that’s made me a more adaptable engineer.

Language and Syntax

Pulumi

• Supports multiple programming languages: Python, TypeScript, Go, C#, Java.
• Uses familiar programming constructs: loops, conditionals, functions.
• Easier for developers already familiar with these languages.

Example (Pulumi - TypeScript):

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

const bucket = new aws.s3.Bucket("my-bucket");

export const bucketName = bucket.id;        

In Pulumi, you use a familiar language like TypeScript and regular programming constructs to define infrastructure.

Terraform

• Uses HashiCorp Configuration Language (HCL): A domain-specific language designed for declaring infrastructure.
• Simpler syntax, but may require learning a new language.

Example (Terraform - HCL):

resource "aws_s3_bucket" "my_bucket" {
  bucket = "my-bucket"
}        

In Terraform, you define infrastructure using HCL, which is concise but requires learning the syntax.

State Management

Pulumi

• State stored in the Pulumi service by default.
• Can use alternative backends: AWS S3, Azure Blob Storage, Google Cloud Storage.
• Automatic state locking to prevent concurrent operations from causing conflicts.

Example (Pulumi - AWS S3 State Backend - TypeScript):

import * as pulumi from "@pulumi/pulumi";

const config = new pulumi.Config();
const stateBackend = {
    backendType: "s3",
    bucket: config.require("stateBucket"),
    key: "pulumi-state",
    region: config.require("region")
};

pulumi.remoteState.s3Backend(stateBackend);        

Terraform

• State stored locally by default.
• Can use remote backends: typically S3.
• Manual state locking in some cases, especially when using non-remote backends. I have used DynamoDB in my past

Example (Terraform - S3 Backend - HCL):

terraform {
  backend "s3" {
    bucket = "my-terraform-state"
    key    = "terraform.tfstate"
    region = "us-west-2"
  }
}        

AWS Support

Pulumi

• Extensive AWS support.
• Often quicker to add support for new AWS services.
• Can use AWS SDK directly for unsupported resources.

Example (Pulumi - AWS SDK Direct Use - Python):

import boto3
from pulumi_aws import s3

bucket = s3.Bucket("my-bucket")

s3_client = boto3.client('s3')
s3_client.put_bucket_versioning(
    Bucket=bucket.id,
    VersioningConfiguration={'Status': 'Enabled'}
)        

Terraform

• Comprehensive AWS provider.
• Large community contributing to AWS resource support.
• May have a slight delay in supporting brand-new AWS features.

Example (Terraform - AWS Provider - HCL):

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

resource "aws_s3_bucket" "my_bucket" {
  bucket = "my-bucket"
}

resource "aws_s3_bucket_versioning" "my_bucket_versioning" {
  bucket = aws_s3_bucket.my_bucket.bucket
  versioning_configuration {
    status = "Enabled"
  }
}        

Ecosystem and Community

Pulumi

• Growing community.
• Fewer third-party modules compared to Terraform.

Example (Pulumi - Reusing Code - TypeScript):

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

// Reuse a function to create an S3 bucket
function createBucket(name: string) {
    return new aws.s3.Bucket(name);
}

const bucket = createBucket("my-bucket");        

Terraform

• Large, established community.
• Extensive collection of modules and providers.

Example (Terraform - Using a Module - HCL):

module "s3_bucket" 
{ 
source = "terraform-aws-modules/s3-bucket/aws" 
version = "~> 3.0" 
bucket = "my-bucket" 
acl = "private" 
}        

Pricing

Pulumi

• Free for individuals and small teams
• Paid plans for larger teams and enterprises

Terraform

• Open-source version is free
• Paid plans for Terraform Cloud and Enterprise features

Conclusion

Both Pulumi and Terraform are excellent choices for managing AWS infrastructure. The best choice depends on your team's skills, project requirements, and existing tooling:

• Choose Pulumi if: Your team is more comfortable with general-purpose programming languages You want to leverage existing programming patterns and tools You need to integrate closely with application code
• Choose Terraform if: You prefer a declarative approach to infrastructure You want a larger ecosystem of modules and providers You need a tool with a gentler learning curve for IaC newcomers

Ultimately, both tools can effectively manage AWS infrastructure, and the choice often comes down to team preference and specific project needs.