Banking System

Table of Contents

• Project Introduction
• Prerequisites
• Installation Guide
• Notes
• Architecture Diagrams
• Usage Instructions
• Api Documentation
• Microservices
• License

Project Introduction

This project simulates a banking system, with a primary focus on demonstrating microservice architecture in a real-world environment.

It adopts a hybrid architecture, where WebClient is used for synchronous interactions, while Apache Kafka enables event-driven processing. The system consists of multiple independent microservices, each handling a specific domain, and follows a stateless design. The project is fully containerized using Docker, ensuring seamless setup and deployment.

Prerequisites

If you want to run this project locally, ensure that you have the following installed and set up on your machine:

1. Docker Desktop Docker is required to run the services in containers. You can download and install Docker Desktop from Docker's official website.

2. Docker Compose Docker Compose is required to run multi-container Docker applications. If you're using Docker Desktop, Docker Compose should be pre-installed. You can check if Docker Compose is installed by running:

   docker-compose --version

3. Java 17

   This project uses Java 17. Make sure you have JDK 17 installed.

4. Enable email notifications

   To fully utilize this project, you need to configure email notifications.

   • The project includes a preconfigured email setup for Gmail. If you're using Gmail, you only need to generate an app password. You can find instructions on how to do this in this guide.
   • If you're using another email provider (e.g., Outlook, Yahoo, etc.), refer to your provider's documentation for SMTP configuration and app password generation.
   • Once you have your credentials, update the docker-compose file (lines 208 and 209) with your email and password:

    - YOUR_USERNAME=yourEmail@gmail.com
    - YOUR_PASSWORD=abcd efgh ijkl mnop 

   • If you are using an email provider other than Gmail, you will also need to update the email configuration settings in the NotificationService application.properties file:

       email.host=smtp.yourprovider.com
       email.port=yourPort

   • NOTES:
     • Ensure that you use a valid and accessible email address for configuration, as this project actively sends emails.
     • Avoid using temporary or incorrect email addresses to prevent sending notifications to unintended recipients.
     • If testing, consider using a dedicated testing email account to avoid disruptions to your primary inbox.
     • To view email examples, refer to the API Documentation section under Email Notifications

5. Postman (Optional)

   If you'd like to test the APIs, I recommend using Postman to easily interact with the services. You can download Postman from the Postman's official website.

   • Postman Web Alternatively, you can use Postman Web directly in your browser. You'll need to sign up for a free account, and you can then import the provided Postman collections to interact with the APIs without downloading anything.

   • The collections are already prepared and available for you to test the API endpoints without manually setting them up. Please refer to API Documentation

6. Minimum system resources

   • RAM: 6 GB (Recommended: 8 GB)
   • Disc Space: 10 GB free

Installation Guide

To deploy the project to your local computer, follow these steps:

1. Clone project

   Clone this repository to your local machine:

    git clone https://github.com/miroslavkolosnjaji/banking-system.git

2. Navigate to the project folder

   Change your directory to the project folder.

    cd banking-system

3. Start the services with Docker Compose

   To start all the services, use docker-compose up command. This will build and start all the necessary contaners for the project.

    docker-compose up --build

The --build flag ensures that Docker Compose rebuilds the images if there are any changes in the Dockerfile or application code.

4. Access the services

   Once the containers are up and running, you can access the services at the following URL:

   • API Gateway: http://localhost:8080
   • Eureka Server: http://localhost:8761
   • Other services will be available via API Gateway. Please check Usage Instructions

Notes

• Make sure that Docker Desktop is running before you attempt to start the services with Docker Compose.

• The first time you build and run the project, it may take approx 10 minutes to download dependencies and set up services.

• The project consumes from 3.5 to 4.5 GB of RAM while running in docker.

• If you want to stop all running services, use the following command:

  docker-compose down

• Note: This project is still under development, and many functionalities have not yet been implemented. Some features may be incomplete or not yet functional.

Architecture Diagrams

• Microservice Architecture: C4 Container Diagram

• ER Diagrams: (This section also includes other Table Schema Diagrams for services with single tables, providing a visual overview of their schema.)

  • Account Service table schema diagram
  • User Service ER diagram
  • Transaction Service table schema diagram

• Document Structure:

  • Notification Service (MongoDb JSON Example)

  {
   "id": "6786b8309a8fc7349888a192",
   "messageId": "91188dfb-4723-43cd-bd0e-c794710017d4",
   "transactionId": 3,
   "userId": 1,
   "accountNumber": "96895****64",
   "amount": 56000.00,
   "balance": 1680000.00,
   "transactionType": "DEPOSIT",
   "description": "Transaction is successfully performed.",
   "status": "SUCCESS",
   "createdAt": "2025-01-14T19:17:04.586Z",
  }

Usage Instructions

Checking if Services are Running

• Open Docker Desktop and make sure all containers are up and running. You should see containers for:

  • api-gateway
  • eureka-server
  • account-service-1
  • account-service-2
  • account-db
  • user-service-1
  • user-service-2
  • user-db
  • transaction-service-1
  • transaction-service-2
  • transaction-db
  • notification-service-1
  • notification-service-2
  • notification-db
  • kafka

Waiting for API Gateway and Services Registration

• API Gateway might take a few moments to fully register all services with Eureka Discovery after starting. During this time, it might not be able to route requests properly.

• Please wait until all services appear in the Eureka Dashboard (accessible at http://localhost:8761) before making any API calls via the API Gateway.

Testing

• Once the setup is complete, you can begin testing the project. A Postman collection with pre-configured API tests is provided and can be found in the API Documentation section. If you're not using Postman, you can still refer to the collection file as a reference for the API endpoints.

API Documentation

For API documentation, including all endpoints, request/response examples, and descriptions, please refer to the Postman collection. This collection contains API requests for managing users, accounts, and transactions in the banking system.

Email Notifications

The system sends email notifications for important account activities. Below are examples of email notifications users receive:

• Deposit Confirmation
• Withdrawal Confirmation
• Transfer Confirmation

Microservices

This project consists of the following microservices:

• Account Service
• Api Gateway
• Eureka Discovery Service
• Notification Service
• Transaction Service
• User Service

Click on the links above to explore the individual service documentation.

License

This project is licensed under the MIT License - see the LICENSE file for details.