add-terraform-module

name	add-terraform-module
description	Scaffold a new Terraform module with variables, main, and outputs. Use when provisioning a new Azure resource (database, cache, storage, etc.) that needs its own Terraform module and Terragrunt wiring.
allowed-tools	Write, Read, Glob, Grep
user-invocable	true

Add Terraform Module

Scaffold a new Terraform module following project conventions.

Arguments

• {module-name} — Name of the module (required, e.g., redis, service-bus)
• {description} — What this module provisions (optional)

Process

1. Read existing modules in infra/terraform/modules/ to follow established patterns.

2. Create the module directory:

infra/terraform/modules/{module-name}/
├── variables.tf
├── main.tf
├── outputs.tf

3. variables.tf — Always include these standard variables:

variable "environment" {
  description = "Environment name (e.g. dev, staging, prod)"
  type        = string
}

variable "location" {
  description = "Azure region"
  type        = string
}

variable "project" {
  description = "Project prefix for resource naming"
  type        = string
  default     = "sb"
}

variable "tags" {
  description = "Common tags applied to all resources"
  type        = map(string)
  default     = {}
}

Add module-specific variables after the standard ones.

4. main.tf — Follow the naming convention from existing modules:

locals {
  location_short = "weu"
  name           = "${var.project}-{resource-abbrev}-${var.environment}-${local.location_short}"
}

5. outputs.tf — Export name, id, and any connection strings or keys needed by downstream modules.

6. Create Terragrunt wiring for dev environment:

infra/terragrunt/dev/{module-name}/
└── terragrunt.hcl

With content:

include "root" {
  path = find_in_parent_folders()
}

terraform {
  source = "../../../terraform/modules/{module-name}"
}

dependency "resource_group" {
  config_path = "../resource-group"
}

inputs = {
  resource_group_name = dependency.resource_group.outputs.name
}

Add additional dependencies based on what the module needs.

Output

After scaffolding, report:

## Scaffolded: {module-name} Terraform module

Files created:
- `infra/terraform/modules/{module-name}/variables.tf`
- `infra/terraform/modules/{module-name}/main.tf`
- `infra/terraform/modules/{module-name}/outputs.tf`
- `infra/terragrunt/dev/{module-name}/terragrunt.hcl`

Next: Add resource definitions in `main.tf`, then run `/infra-lint` to validate.

Error Handling

• Module directory already exists: Warn the user and ask whether to overwrite or extend.
• Terraform not installed: Suggest installing with brew install terraform.
• Terragrunt root config not found: Check that infra/terragrunt/terragrunt.hcl exists as the root config.

After Scaffolding

Remind to:

• Add module-specific resource definitions in main.tf
• Add any needed dependencies in terragrunt.hcl
• Run /infra-lint to validate