📦 PixelProxy

PixelProxy is a scalable, containerized reverse proxy system built with Node.js and Express, managed via Docker Compose. It includes a centralized logging stack powered by Loki, Promtail, and Grafana, and features a CircleCI-based CI/CD pipeline for secure, automated deployment.

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📌 Architecture Overview

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🏗️ Application Layers

🌐 Client Layer

• Multiple clients (Web Browsers on Desktop and Mobile) access the system.

🔄 Load Balancer Layer

• Nginx Load Balancer

  • Listens on port 80
  • Uses least-connections algorithm
  • Has failover support for backup server

🧱 Application Layer

• PixelProxy Instances (Node.js/Express):

  • PixelProxy 1: 3001:3000
  • PixelProxy 2: 3002:3000
  • PixelProxy 3: 3003:3000
  • Backup Proxy: 3004:3000 (activated only when primaries fail)

• Environment Variables: APP_NAME

• Live Reload: Docker Compose Watch enabled

🌐 Network Layer

• Custom Docker network: pixpro-network

  • Supports internal container communication
  • External ports: 80, 3001-3004

💾 File System

• Volume Mounts:

  • nginx.conf: Configuration
  • nginx/logs/: Access/Error Logs

📊 Centralized Logging System

• Promtail collects logs from Nginx
• Loki stores logs
• Grafana visualizes logs in real-time

🔁 Traffic Flow

• Clients → Nginx → Least-busy PixelProxy
• Backup traffic (dashed line) to backup server only when needed

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🚧 Development Features

• 🔁 Live Reload with Docker Compose Watch
• 📂 File Syncing
• ❌ Ignored Paths: node_modules/, logs/, .git/

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⚙️ CI/CD Pipeline (CircleCI)

1. 🛠️ Checkout code
2. 🏗️ Build Docker image
3. ▶️ Run docker-compose
4. 🔍 Trivy security scan
5. 🔐 Docker Hub login
6. 🏷️ Tag and push image

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🚀 Getting Started

Prerequisites

• Docker & Docker Compose
• Node.js
• CircleCI account (optional for CI/CD)

Development Build

docker-compose up --build

Logging Stack Build ( Grafana )

docker compose -f docker-compose.logging.yml up --build

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🩺 Health Checks

• Internal endpoints expose health status
• Health checks used by Docker and monitoring tools

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🔖 Versioning

Component	Version
Node.js	23-alpine
Express	4.x
Nginx	latest
Docker Compose	v2+
Grafana	10.x
Loki	latest
Promtail	latest

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🧪 Security

• Automated scanning with Trivy
• Minimal base images
• Regular dependency updates

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📈 Monitoring Dashboard

Visit Grafana at: http://localhost:3000 Default credentials:

• User: admin
• Password: admin