FeedApp - DAT250 Software Technologies Project (Group 8)

Welcome to the FeedApp project! This repository contains a full-stack polling application designed to demonstrate the integration of a modern, containerized technology stack. The project serves as both a functional prototype and a formal technology assessment of Apache Kafka as a featured technology, compared against a RabbitMQ baseline.

Key Features

• Full-Stack Architecture: A reactive Svelte frontend communicating with a stateless Spring Boot 3 backend.
• JWT-Based Security: Secure user registration and authentication using JSON Web Tokens.
• Asynchronous Messaging: Utilizes Kafka (or RabbitMQ) to decouple high-volume vote ingestion from database persistence.
• Polyglot Persistence: Employs H2 for relational data integrity and Valkey (Redis) for high-performance caching of poll results.
• Containerized Deployment: The entire application and its services are orchestrated via Docker Compose for easy, one-command setup.

Technology Stack

Category	Technology	Role in Project
Backend	Java 25 & Spring Boot 3	Core application framework and dependency injection.
	Spring Web MVC	Exposes the stateless REST API.
	Spring Security	Handles JWT-based authentication and authorization.
Frontend	Svelte & SvelteKit	A reactive, component-based Single Page Application (SPA).
Database & Cache	H2 (File-based)	Relational database for primary data persistence.
	Valkey	In-memory cache for optimizing read-heavy operations (vote counts).
	JPA & Hibernate	Object-Relational Mapping (ORM) layer.
Messaging	Apache Kafka (Featured)	High-throughput, durable event streaming for vote processing.
	RabbitMQ (Baseline)	Traditional message broker used for comparison.
DevOps	Docker & Docker Compose	Containerization and orchestration of the entire stack.
	GitHub Actions	Continuous Integration pipeline for building and pushing the public Docker image.

Getting Started

This guide explains how to configure and run the application.

Prerequisites

• Docker
• Docker Compose

1. Configuration

The application is configured using a single .env file in the project root.

1. Create a file named .env in the root of the project.

2. Use the template below:

   # A long, random string to secure JWTs.
   # You can generate one with: openssl rand -base64 32
   JWT_SECRET=your-super-secret-key-goes-here
   
   # The active messaging profile. Switch between 'kafka' and 'rabbitmq'.
   SPRING_PROFILES_ACTIVE=kafka

2. Running the Application

There are two methods to run the project, depending on your goal.

Option A: Integrated Build (Recommended for Development)

This method builds the application from the local source code and runs all services together.

docker compose up --build -d

Option B: Standalone Image

This method pulls the pre-built public image from Docker Hub and connects it to the infrastructure, simulating how an external user would run it.

1. Start the infrastructure services first:

   docker compose up -d kafka kafka-ui valkey rabbitmq

2. Run the application container manually. (Note: Ensure your network is named dat250-feedapp-group8_default. Check with docker network ls if it differs.)

   docker run --rm --network dat250-feedapp-group8_default -p 8080:8080 \
     -e JWT_SECRET=${JWT_SECRET} \
     -e SPRING_PROFILES_ACTIVE=${SPRING_PROFILES_ACTIVE} \
     -e VALKEY_HOST="valkey" \
     -e SPRING_KAFKA_BOOTSTRAP_SERVERS="kafka:9092" \
     -e SPRING_RABBITMQ_HOST="rabbitmq" \
     --name feedapp-manual \
     olefb/feedapp:latest

3. Exploring the System

Once running, the following services are available:

Service	URL	Credentials
FeedApp Frontend	http://localhost:8080	N/A
H2 Database Console	http://localhost:8080/h2-console	User: admin, Pass: (none)
Kafka UI	http://localhost:8081	N/A
RabbitMQ Management	http://localhost:15672	User: guest, Pass: guest