A Practical Guide to Structuring Terraform Modules for Long-Term Maintainability

A systems practitioner has shared an opinionated but widely applicable layout for organizing Terraform modules, addressing the common problem of bloated, poorly documented repositories. The approach assigns fixed roles to specific files — such as data.tf for data sources, providers.tf for provider configuration, and terraform.tf solely for required_version — which always exist even when empty. Variables are split into required and optional sections, both alphabetized, so the top of variables.tf clearly communicates a module's contract at a glance. Resources remain in main.tf until roughly twenty accumulate, at which point they are split into service-specific files like network.tf or iam.tf. Tooling such as terraform-docs, tflint, trivy, and pre-commit hooks are recommended to automate documentation and catch issues before a plan runs.