Dynamic Module Creation and Publishing on Terraform Registry

Objective

The goal of this task is to design, develop, and publish reusable Terraform modules for VPC, EC2, and RDS that can be used across multiple AWS environments. These modules will be published to the Terraform Registry to ensure easy sharing and versioning.

Technologies Used

• Terraform (Infrastructure as Code)
• AWS Services: VPC, EC2, RDS
• Git & GitHub/GitLab/Bitbucket (Version Control & CI/CD)
• Terraform Cloud/Terraform Registry (Publishing Modules)
• AWS IAM, Security Groups, S3 (Permissions & Storage)

Task Implementation Steps

Phase 1: Designing Terraform Modules

We will create three separate Terraform modules:

1. VPC Module
2. EC2 Module
3. RDS Module

Each module will be self-contained, reusable, and parameterized.

Phase 2: Implementing the Modules

1. VPC Module

Features:

• Create a custom VPC with CIDR block as an input variable.
• Define public and private subnets dynamically.
• Set up an Internet Gateway (IGW) for public subnets.
• Define Route Tables and Associations.
• Implement NAT Gateway for private subnets.

Files:

• variables.tf (Define input variables like CIDR, subnet count, region)
• main.tf (VPC resource creation)
• outputs.tf (VPC ID, Subnet IDs, Route Table IDs)

2. EC2 Module

Features:

• Create EC2 instances with configurable instance types.
• Attach an Elastic IP (EIP) to public instances.
• Define IAM Role & Instance Profile.
• Allow dynamic Security Group (SG) rules.

Files:

• variables.tf (AMI, instance type, key pair, SG rules)
• main.tf (EC2, EBS Volume, IAM Role)
• outputs.tf (Instance ID, Public/Private IP)

3. RDS Module

Features:

• Create an RDS Instance (PostgreSQL/MySQL).
• Define DB Subnet Groups in private subnets.
• Enable multi-AZ deployment for high availability.
• Configure parameter groups & security groups.

Files:

• variables.tf (DB type, username, password, storage)
• main.tf (RDS resource creation)
• outputs.tf (DB endpoint, DB name)

Phase 3: Testing and Publishing

1. Version Control & GitHub Setup

• Create a GitHub repository for each module (terraform-aws-vpc, terraform-aws-ec2, terraform-aws-rds).
• Maintain a structured module directory:

/terraform-aws-vpc/
    ├── main.tf
    ├── variables.tf
    ├── outputs.tf
    ├── README.md
    

• Use branching strategy (main, dev, feature-branch).

2. Terraform Cloud Testing

• Test each module individually by calling them in a separate Terraform root module.
• Execute terraform apply to validate module functionality.

3. Publishing to Terraform Registry

• Ensure README.md is well-documented with inputs, outputs, examples.
• Add a semantic version tag (v1.0.0).
• Push to GitHub and link with Terraform Registry.

Commands for Publishing:

1. Tag and push version

git tag v1.0.0
git push origin v1.0.0

2. Verify in Terraform Registry
   • Log in to Terraform Registry
   • Navigate to "Publish a Module"
   • Link the GitHub repository

Phase 4: Usage Example

To use the modules, create a Terraform configuration:

module "vpc" {
  source  = "github.com/user/terraform-aws-vpc"
  vpc_cidr = "10.0.0.0/16"
}

module "ec2" {
  source      = "github.com/user/terraform-aws-ec2"
  instance_type = "t3.micro"
  vpc_id      = module.vpc.vpc_id
}

module "rds" {
  source  = "github.com/user/terraform-aws-rds"
  db_name = "mydatabase"
  vpc_id  = module.vpc.vpc_id
}
    

Project Deliverables

• ✅ Terraform Modules for VPC, EC2, and RDS
• ✅ GitHub Repository with Structured Code & README
• ✅ Terraform Registry Published Modules
• ✅ Version Control for Continuous Improvement

Next Steps

• Implement CI/CD pipelines for automated testing of Terraform modules.
• Enhance observability using CloudWatch and Terraform state management.
• Extend modules to support multi-region deployments.

This end-to-end guide is ready for implementation. Let me know if you need additional details on any step! 🚀