Why Terragrunt for DRY configurations in Terraform? - Purpose & Use Cases

The Big Idea

What if you could fix one file and update all your cloud environments instantly?

The Scenario

Imagine you manage many cloud environments, each needing similar setup but with slight differences. You copy-paste configuration files for each environment and tweak them manually.

The Problem

This manual copying is slow and risky. One small mistake in one file can cause failures. Updating common settings means editing many files, increasing errors and wasted time.

The Solution

Terragrunt lets you write shared configuration once and reuse it everywhere. It keeps your setup clean, consistent, and easy to update, saving time and avoiding mistakes.

Before vs After

✗ Before

resource "aws_s3_bucket" "bucket" {
  bucket = "my-app-dev"
  acl    = "private"
}

# Repeat for prod, staging with slight changes

✓ After

include {
  path = find_in_parent_folders()
}

inputs = {
  bucket_name = "my-app-${local.env}"
}

What It Enables

With Terragrunt, you can manage many environments confidently, making updates once and applying everywhere automatically.

Real Life Example

A company managing dev, staging, and production clouds uses Terragrunt to keep all environments aligned and quickly roll out changes without errors.

Key Takeaways

Manual copying of configs is slow and error-prone.

Terragrunt centralizes shared settings for easy reuse.

It boosts reliability and speeds up cloud management.