Mastering Terraform Modules: A Guide to Building Reusable Infrastructure

Imagine you are a DevOps engineer tasked with managing infrastructure across fifty different AWS accounts. In every single account, you need to deploy a standard set of resources: a VPC, a specific set of security groups, and an S3 bucket for logging. If you write the raw Terraform code for these resources fifty times, you aren't just wasting time—you are creating a massive maintenance headache. If the security team decides that all S3 buckets must now have versioning enabled, you would have to manually update fifty different files. This is where the Don't Repeat Yourself (DRY) principle becomes essential.