☁️ Mingle - Cloud SaaS Application

University Coursework: Cloud Computing (BUCI028H6)

Mingle is a RESTful Software-as-a-Service (SaaS) application designed to mimic social media functionality similar to Twitter. It allows users to post messages, browse topics, and interact via likes, dislikes, and comments.

The project demonstrates advanced cloud-native development practices, traversing the full spectrum from Local Development to Virtual Machine Deployment (Docker) and finally Orchestration (Kubernetes/GKE).

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🛠 Tech Stack

• Backend: Node.js, Express.js
• Database: MongoDB, Mongoose
• Authentication: Passport.js (Google OAuth 2.0), JWT (JSON Web Tokens), BCrypt
• Containerization: Docker, Docker Compose
• Orchestration: Google Kubernetes Engine (GKE)
• Security & Networking: NGINX Ingress Controller, Cert-Manager (Let's Encrypt), sslip.io

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📂 Project Structure

MINGLE/
├── config/             # Passport.js & OAuth configuration
├── k8s/                # Kubernetes Manifests (Deployment, Service, Ingress, Secrets)
├── middleware/         # Auth & Validation Middleware
├── models/             # Mongoose Schemas (User, Post)
├── routes/             # API Route Definitions
├── test/               # Automated Test Scripts
├── app.js              # Application Entry Point
├── Dockerfile          # Docker Image Build Instructions
└── docker-compose.yml  # Local & VM Orchestration

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✨ Key Features

🔐 Authentication & Security

• Dual Authentication: Supports both Local Email/Password and Google OAuth 2.0.
• Stateless Sessions: Uses JWT Bearer tokens for scalable, stateless API access.
• Production Security: Full HTTPS/TLS termination using Let's Encrypt and NGINX Ingress.

📱 Core Functionality

• Posting: Users can create posts with specific topics (Tech, Health, Sport, Politics) and expiration times.
• Browsing: Filter posts by topic and status (Live vs. Expired).
• Interactions: Like, Dislike, and Comment on posts.
• Validation: Strict input validation using express-validator.

📊 Analytics

• Activity Tracking: Query for the "Most Active" post per topic based on engagement scores.
• History: Browse archived/expired posts.

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🚀 Getting Started (Local Development)

To run the application locally using Docker Compose:

1. Clone the repository:

   git clone https://github.com/hf5296/Mingle.git
   cd mingle

2. Configure Environment: Create a .env file in the root directory (see .env.example).

3. Run with Docker Compose:

   docker-compose up --build

   • API will be available at: http://localhost:3000
   • MongoDB will be available at: localhost:27017

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☁️ Cloud Deployment (Docker VM)

For Phase E, the application was deployed to a standard Linux Virtual Machine (Google Compute Engine) using Docker Compose. This demonstrates the ability to deploy containerized applications without full orchestration overhead.

1. Provision VM: Create a standard Ubuntu VM on Google Cloud and open port 3000 in the Firewall.
2. Environment Setup: SSH into the VM and install Docker Engine & Compose.
3. Deploy:

   git clone https://github.com/hf5296/Mingle.git
   cd mingle
   # Create production .env file
   nano .env 
   # Launch in detached mode
   docker-compose up -d

   • API Access: http://<VM-PUBLIC-IP>:3000

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☸️ Cloud Orchestration (Kubernetes / GKE)

For the final phase, the project was migrated to a production-grade architecture on Google Kubernetes Engine (GKE), utilizing Ingress for Layer 7 routing and Cert-Manager for automatic SSL.

1. Prerequisite Infrastructure

Install the NGINX Ingress Controller and Cert-Manager on the cluster:

# Install NGINX Ingress
kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v1.14.0/deploy/static/provider/cloud/deploy.yaml

# Install Cert-Manager
kubectl apply -f https://github.com/cert-manager/cert-manager/releases/download/v1.19.1/cert-manager.yaml

2. Deployment

Apply the Kubernetes manifests located in the k8s/ directory.

# 1. Configure SSL Issuer
kubectl apply -f k8s/issuer.yaml

# 2. Apply Secrets (Contains Base64 encoded Google Credentials & DB URI)
kubectl apply -f k8s/secrets.yaml

# 3. Deploy Database (StatefulSet for data persistence)
kubectl apply -f k8s/mongo.yaml

# 4. Deploy API & Ingress Rules
kubectl apply -f k8s/api.yaml

3. DNS & Security Configuration

The deployment uses sslip.io to map the Ingress External IP to a secure domain for Google OAuth compatibility.

• URL: https://mingle.<EXTERNAL-IP>.sslip.io
• Status: Secured with Let's Encrypt R3 Certificate.

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🧪 Testing

Automated Testing

The project includes a custom test suite (test/mingle_tests.js) that automates the user registration and authentication flow (TC1-TC3).

# Run the test suite
npm test

Postman Integration

The test suite automatically exports valid JWT tokens to test/postman_data.json. These can be imported into Postman to manually test advanced features (Posting, Liking, Browsing) without manually copying tokens.

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📝 License

This project was developed for academic purposes.