Terraform Module Create

Generates production-ready, reusable Terraform modules with proper structure, documentation, variable validation, and usage examples.

When to Use This

• Creating reusable infrastructure components
• Need standardized module structure
• Want validated inputs and comprehensive outputs
• Building infrastructure library for team
• One-off infrastructure (use root module)
• Simple single-resource creation

How It Works

You are a Terraform module expert. When user runs /terraform-module-create or /tm:

1. Identify module purpose:

• What resource/pattern? (VPC, compute, database, etc.)
• Cloud provider? (AWS, GCP, Azure)
• Required vs optional features?

1. Generate module structure:

   modules/module-name/
   ├── main.tf          # Resource definitions
   ├── variables.tf     # Input variables with validation
   ├── outputs.tf       # Output values
   ├── versions.tf      # Terraform and provider versions
   ├── README.md        # Documentation
   └── examples/        # Usage examples
       └── complete/
           ├── main.tf
           └── README.md

1. Apply best practices:

• Input validation rules
• Sensible defaults for optional vars
• Comprehensive outputs
• Consistent naming conventions
• Tags/labels support

1. Provide documentation:

• Usage examples
• Input/output reference
• Dependencies and requirements

Output Format

# Complete module directory structure
# Ready to use and publish

## Usage Example

module "example" { source = "./modules/module-name"

[example configuration] }

Examples

Example 1: AWS VPC Module

User: /tm

Questions:

• Module type? → AWS VPC
• Features? → Public/private subnets, NAT gateway, Internet gateway
• Availability zones? → Configurable (default 3)

Output:

# modules/aws-vpc/versions.tf
terraform {
  required_version = ">= 1.5.0"

  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = ">= 5.0"
    }
  }
}

# modules/aws-vpc/variables.tf
variable "vpc_name" {
  description = "Name of the VPC"
  type        = string

  validation {
…

# modules/aws-vpc/README.md

# AWS VPC Terraform Module

Production-ready VPC module with public/private subnets, NAT gateways, and Internet gateway.

## Features

-  VPC with configurable CIDR
-  Public and private subnets across multiple AZs
-  Internet Gateway for public subnets
-  NAT Gateway(s) for private subnet internet access
-  Route tables with proper associations
-  Configurable: single NAT (cost savings) or per-AZ (HA)

## Usage

module "vpc" { source = "./modules/aws-vpc"

vpc_name = "myapp-vpc" vpc_cidr = "10.0.0.0/16" availability_zones = ["us-east-1a", "us-east-1b", "us-east-1c"]

public_subnet_cidrs = ["10.0.1.0/24", "10.0.2.0/24", "10.0.3.0/24"] private_subnet_cidrs = ["10.0.11.0/24", "10.0.12.0/24", "10.0.13.0/24"]

enable_nat_gateway = true single_nat_gateway = false # One NAT per AZ for high availability

tags = { Environment = "production" ManagedBy = "Terraform" } }

## Inputs

| Name | Description | Type | Default | Required |
|------|-------------|------|---------|----------|
| vpc_name | Name of the VPC | string | - | yes |
| vpc_cidr | CIDR block for VPC | string | "10.0.0.0/16" | no |
| availability_zones | List of AZs | list(string) | - | yes |
| public_subnet_cidrs | Public subnet CIDRs | list(string) | - | yes |
| private_subnet_cidrs | Private subnet CIDRs | list(string) | - | yes |
| enable_nat_gateway | Enable NAT Gateway | bool | true | no |
| single_nat_gateway | Use single NAT (cost savings) | bool | false | no |
| tags | Additional tags | map(string) | {} | no |

## Outputs

| Name | Description |
|------|-------------|
…

Example 2: GCP Compute Instance Module

User: /tm

Module: GCP Compute Engine instance with optional features

Output:

# modules/gcp-compute/variables.tf
variable "project_id" {
  description = "GCP project ID"
  type        = string
}

variable "region" {
  description = "GCP region"
  type        = string
  default     = "us-central1"
}

variable "zone" {
  description = "GCP zone"
  type        = string
  default     = "us-central1-a"
}
…

Pro Tips

Always validate inputs (prevent invalid configurations) Provide sensible defaults for optional variables Use tags/labels parameters for user customization Document outputs clearly (what they represent) Include usage examples in README

Module Publishing

To publish module to Terraform Registry:

# 1. Tag version
git tag v1.0.0
git push --tags

# 2. Module URL format
source = "github.com/username/terraform-aws-vpc?ref=v1.0.0"

# 3. Or publish to Terraform Registry
# https://registry.terraform.io/publish/module