Project Portfolio: Infrastructure as code (IaC) with Terraform and Docker

Project Goal

This project documents a comprehensive journey through modern DevOps practices, from building a CI/CD pipeline to managing infrastructure as code. The primary objective was to master the full lifecycle of a containerized application, including automated builds, "multi-container" orchestration, and declarative infrastructure management with Terraform.

---

Architecture and Workflow

The final architecture demonstrates a professional, multi-stage workflow controlled by code:

Terraform Code -> Terraform Engine -> Docker Engine API -> (NGINX Container <=> Private Network <=> Node.js Container)

1. Infrastructure as Code (IaC): Terraform is used as the single source of truth to define all components: the Docker containers, the private network connecting them, and port mappings. This replaces manual docker commands with a declarative, version-controlled system.
2. CI/CD Automation: A Jenkins pipeline automatically builds the application's Docker image whenever new code is pushed, ensuring a reliable and repeatable build process.

---

Key Learnings & Troubleshooting Gauntlet

This journey combined high-level IaC concepts with a series of hands-on, real-world debugging challenges.

IaC Concepts Mastered

• Declarative Infrastructure: We learned to define the desired end state in .tf files, allowing Terraform to handle the complex logic of creating, updating, and destroying resources.
• The Plan/Apply/Destroy Cycle: We mastered the critical workflow of using terraform plan for safe previews, terraform apply to execute changes, and terraform destroy for clean resource removal.
• State Management: We understood the role of the terraform.tfstate file as Terraform's "memory," which is essential for managing infrastructure over its lifecycle.

Real-World Debugging Showcase

Challenge 1: CI/CD Pipeline Setup (Jenkins)

• Error: npm: not found during the build stage.
  • Solution: Resolved by replacing the minimal default agent with a Docker Agent (node:20-alpine), ensuring a consistent and dependency-complete build environment.
• Error: docker: not found (The Docker-in-Docker Problem).
  • Solution: Solved by mounting the host's Docker socket (-v /var/run/docker.sock...) into the Jenkins container, granting it permission to execute docker commands.

Challenge 2: Multi-Container Communication (Nginx + Node.js)

• Error: 502 Bad Gateway due to network isolation.
  • Solution: Created a dedicated docker_network in Terraform, allowing the Nginx and Node.js containers to communicate securely over a private network.
• Error: 502 Bad Gateway due to an application crash.
  • Solution: Inspected container logs (docker logs) to find a fatal error caused by a broken beta version of the express dependency. Pinned the version in package.json to a known stable release.
• Error: Lingering 502 Bad Gateway due to a stale cache.
  • Solution: After fixing the code, the issue persisted. A full system cleanup with docker system prune -a -f cleared Docker's cache, forcing a fresh image rebuild with the corrected code.

---

Future Development: The AI UI Builder Vision

This project serves as the essential foundational groundwork for a more ambitious future application: an AI UI Builder. The robust IaC and CI/CD skills practiced here are the critical building blocks required to design, deploy, and manage the complex backend systems needed for such an advanced tool.