Online Banking Microservices API

A modern, scalable online banking system built using a microservices architecture with Java, Spring Boot, Apache Kafka, PostgreSQL, JPA/Hibernate, Docker, and more. This project demonstrates a modular, event-driven banking application with services for account management, transactions, loans, notifications, and authentication.

Table of Contents

• Features
• Technologies
• Prerequisites
• Setup and Installation
• Running the Application
• Services
• Environment Variables
• Contributing
• License

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Features

• Account Management: Create, update, and manage user accounts and balances.
• Transaction Processing: Handle transfers, payments, and transaction history.
• Loan Management: Process loan applications, schedules, and credit scoring.
• Notification System: Send emails and SMS notifications using event-driven architecture.
• Authentication: Secure user authentication with JWT/OAuth2 via Keycloak.
• Service Discovery: Dynamic service registration and discovery with Eureka.
• Distributed Tracing: Monitor requests with Zipkin.
• Caching: Improve performance with EhCache .
• Event-Driven Communication: Asynchronous messaging with Kafka.

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Technologies

• Backend: Java, Spring Boot, Spring Cloud
• Databases: PostgreSQL (JPA/Hibernate), MongoDB
• Message Broker: Apache Kafka, Zookeeper
• Authentication: Keycloak (JWT/OAuth2)
• Service Discovery: Netflix Eureka
• API Gateway: Spring Cloud Gateway
• Distributed Tracing: Zipkin

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Prerequisites

• Docker: Version 20.10 or higher
• Docker Compose: Version 1.29 or higher
• Java: JDK 17 (for local development)
• Maven: For building Spring Boot services
• Git: To clone the repository
• Containerization: Docker, Docker Compose
• Monitoring: pgAdmin, Mongo Express
• Email Testing: Maildev

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Setup and Installation

1. Clone the Repository:

   git clone https://github.com/your-username/online-banking-microservices-api.git
   cd online-banking-microservices-api

2. Build the Project (optional, if running locally without Docker):

mvn clean install

3. Configure Environment Variables:
   • See the Environment Variables (#environment-variables) section for details.
   • Update the docker-compose.yml file if needed.

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Running the Application

1. Start the Services with Docker Compose:

   docker-compose up -d
   

2. Verify Services:

• PostgreSQL: localhost:5432
• Keycloak: localhost:9098
• pgAdmin: localhost:5050
• Zipkin: localhost:9411
• MongoDB: localhost:27017
• Mongo Express: localhost:8081
• Kafka: localhost:9092
• Maildev: localhost:1080 (UI), localhost:1025 (SMTP)

3. Stop the Services

docker-compose down

Services

| Service            | Description                          | Port       |
|--------------------|--------------------------------------|------------|
| **PostgreSQL**     | Relational database for core data    | 5432       |
| **Keycloak**       | Authentication and authorization     | 9098       |
| **pgAdmin**        | PostgreSQL management UI             | 5050       |
| **Zipkin**         | Distributed tracing                  | 9411       |
| **MongoDB**        | NoSQL database for notifications     | 27017      |
| **Mongo Express**  | MongoDB management UI                | 8081       |
| **Zookeeper**      | Kafka coordination                   | 22181      |
| **Kafka**          | Message broker                       | 9092       |
| **Maildev**        | Email testing server                 | 1080, 1025 |

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Environment Variables

The following environment variables are defined in docker-compose.yml. Customize them as needed:

Variable	Default Value	Description
POSTGRES_USER	postgres	PostgreSQL username
POSTGRES_PASSWORD	admin@123	PostgreSQL password
KEYCLOAK_ADMIN	admin	Keycloak admin username
KEYCLOAK_ADMIN_PASSWORD	admin	Keycloak admin password
PGADMIN_DEFAULT_EMAIL	[email protected]	pgAdmin login email
PGADMIN_DEFAULT_PASSWORD	admin	pgAdmin login password
MONGO_INITDB_ROOT_USERNAME	root	MongoDB root username
MONGO_INITDB_ROOT_PASSWORD	password	MongoDB root password

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Contributing

1. Fork the repository.
2. Create a feature branch (git checkout -b feature/your-feature).
3. Commit your changes (git commit -m "Add your feature").
4. Push to the branch (git push origin feature/your-feature).
5. Open a Pull Request.