🚀 Contact API — Production-Ready Spring Boot Backend

A production-grade backend system built with Spring Boot, containerised using Docker, and deployed on a VPS with zero-downtime blue-green deployment, NGINX reverse proxy, and full monitoring using Prometheus & Grafana.

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🏗️ Architecture Overview

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⚙️ Detailed System Architecture

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🚀 Key Features

• 🔁 Blue-Green Deployment (Zero Downtime)
• 🐳 Dockerized Application
• 🌐 NGINX Reverse Proxy Routing
• 📊 Monitoring with Prometheus & Grafana
• 🛢️ PostgreSQL Database Integration
• ⚙️ CI/CD via GitHub + GHCR
• 🔐 Environment-based Configuration (.env)
• 📈 Production Observability Setup

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🧱 Tech Stack

Layer	Technology
Backend	Spring Boot
Database	PostgreSQL
Container	Docker
Proxy	NGINX
Monitoring	Prometheus, Grafana
CI/CD	GitHub Actions, GHCR
Deployment	VPS (Linux)

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🔁 Deployment Strategy (Blue-Green)

This project implements a blue-green deployment strategy to ensure zero downtime.

Flow:

1. New version is deployed to inactive environment (Green)

2. Health checks are verified

3. NGINX switches traffic:

   Blue → Green
   

4. Old version remains as a fallback

Result:

• ✅ Zero downtime
• ✅ Instant rollback capability
• ✅ Safe production deployments

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📊 Monitoring & Observability

• Prometheus scrapes metrics from:

  /actuator/prometheus
  

• Grafana visualizes:

  • CPU usage
  • Memory usage
  • Request metrics
  • Container health

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🐳 Docker Setup

Run with Docker Compose

docker-compose up -d

Services:

• contact-api (blue/green)
• postgres
• prometheus
• grafana
• nginx

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🌐 API Endpoints

Method	Endpoint	Description
GET	/contacts	Get all contacts
POST	/contacts	Create contact
GET	/contacts/{id}	Get contact by ID
PUT	/contacts/{id}	Update contact
DELETE	/contacts/{id}	Delete contact

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🧪 Run Locally

git clone https://github.com/vimal-java-dev/vimaltech-contact-api
cd vimaltech-contact-api

docker-compose up --build

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☁️ Production Deployment

Steps:

1. Push Docker image to GHCR
2. Pull the image on the VPS
3. Run deploy.sh
4. Switch NGINX between blue/green

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🔐 Security Considerations

• Environment variables via .env
• NGINX as reverse proxy (no direct exposure)
• Container isolation
• Controlled port exposure

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📸 Screenshots (Add Here)

Add:

• Grafana dashboard
• Prometheus targets
• Docker containers
• Blue-Green switch logs

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🎯 What This Project Demonstrates

• Real-world backend system design
• DevOps integration with backend development
• Zero-downtime deployment strategy
• Monitoring & observability setup
• Production-ready architecture thinking

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🌍 Live Demo

👉 https://vimaltech.dev/

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👨‍💻 Author

Vimal Patel

Backend Developer | Spring Boot | DevOps Enthusiast

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