Terraform AWS ECS Fargate Infrastructure
Designed and provisioned a production-style container infrastructure on AWS using Terraform, ECS Fargate, and an Application Load Balancer, following real-world DevOps and cloud architecture best practices.
Completed🎯 Problem & Objective
The challenge was to deploy a containerized application that balances security, simplicity, and scalability while remaining fully reproducible using Infrastructure as Code. The objective was to expose the application securely through a load balancer, keep compute resources private, reduce operational overhead, and ensure the infrastructure could be reliably created, modified, and destroyed.
🏗️ High-Level Architecture
The architecture follows a layered and modular approach that separates networking, load balancing, and compute responsibilities. A VPC provides clearly defined public and private subnets, with the Application Load Balancer acting as the sole public entry point. ECS Fargate tasks run privately within the VPC, ensuring controlled traffic flow and reduced attack surface.
🧠 Key Design Decisions
The following design decisions were made to align the infrastructure with modern, production-style cloud and DevOps best practices.
- ECS Fargate: Selected to remove the need for EC2 instance and host management, allowing focus on infrastructure design and container orchestration rather than server maintenance.
- Private Subnets for ECS Tasks: Containers are deployed in private subnets to reduce the attack surface. All inbound traffic is routed through the Application Load Balancer, enforcing a clear network boundary.
- Terraform Modules: Infrastructure components such as VPC, ALB, and ECS were isolated into modules to improve reusability, simplify debugging, and maintain separation of concerns.
- Remote State Management: Terraform remote state was configured to ensure state persistence, prevent drift, and support safe iteration and collaboration.
🛠 Tools & Technologies
✅ Execution & Verification
The infrastructure was built incrementally, starting with the networking layer, followed by the Application Load Balancer, and finally the ECS Fargate resources. Each layer was validated independently before proceeding, reducing risk and avoiding large, error-prone deployments.
🚧 Challenges Faced
Challenges included understanding Terraform module boundaries versus environment execution, early misconfiguration of remote state, IAM profile confusion across sessions, and file path issues when structuring modules. These issues reinforced the importance of execution context and structure in Infrastructure as Code.
💡 Key Learnings
This project reinforced several core DevOps and cloud engineering principles that closely mirror real production experiences.
- Clear Terraform module boundaries significantly improve infrastructure scalability, readability, and long-term maintainability.
- Terraform execution context is just as important as the code itself. Running commands from the correct directory and environment prevents unexpected behavior and configuration issues.
- Incremental validation during infrastructure builds saves time and reduces cognitive load compared to large, single-step deployments.
- Cost awareness should influence architectural decisions early, especially when designing networking and managed service components.
- Small configuration details such as file paths, remote state handling, and AWS profiles can have a large operational impact if misconfigured.
✅ Outcome and Final Result
The final result is a fully functional ECS Fargate service running in private subnets and receiving traffic exclusively through an Application Load Balancer.
The infrastructure is modular, reproducible, and safely managed through Terraform remote state, allowing it to be created, modified, or destroyed with confidence.
🔮 Future Improvements
- HTTPS termination using ACM
- ECS service autoscaling policies
- CI/CD pipeline for automated deployments
- Blue-green deployment strategies
- Enhanced monitoring and alerting
🚫 Git LFS & Terraform Providers
GitHub suggested Git Large File Storage due to the size of Terraform provider binaries. However, provider binaries should never be versioned. The correct practice is to exclude the .terraform directory and allow Terraform to download providers dynamically during initialization, keeping repositories lightweight and portable.
✨ Closing Reflection
This project strengthened my confidence in designing cloud infrastructure using Terraform and reinforced the importance of clarity, structure, and incremental delivery. It reflects a growing DevOps mindset focused on building systems that are secure, reliable, and maintainable.