Welcome to this comprehensive guide to building an e-commerce web application using Domain-Driven Design (DDD) and microservices architecture. This roadmap is tailored for learners who want to explore the intricacies of modern application development.
This project is a step-by-step guide to developing an e-commerce web application using the principles of Domain-Driven Design (DDD) and microservices architecture. The primary goal is to provide a hands-on learning experience, covering the entire development lifecycle, from setting up the infrastructure to deploying a secure, fully-functional application.
Our application architecture is based on the following core principles:
- Domain-Driven Design (DDD): Structuring the application around the business domain to ensure a clean and maintainable codebase.
- Microservices: Decoupling the application into independent services that can be developed, deployed, and scaled individually.
- Event-Driven Communication: Using Kafka to enable asynchronous communication between services.
Below is a global diagram of the architecture:
We adopt a mono repo approach, which allows us to manage all microservices and related components within a single repository. This simplifies dependency management and ensures consistency across the project.
To set up the project, we'll use the following tools:
- Spring Boot & Spring Cloud: For building and managing microservices.
- Docker & Docker Compose: For containerization and environment setup.
- Kafka & Zookeeper: For handling event-driven communication.
- Zipkin: For distributed tracing.
- Keycloak: For securing the application.
We begin by creating a Configuration Server that centralizes all configurations for the microservices, ensuring consistent configuration management.
Next, we'll set up a Discovery Server (using Eureka) to manage service discovery, allowing microservices to locate each other without hardcoded URLs.
The Customer Microservice will handle all customer-related operations. This includes:
- Creating customer entities
- Initializing the database
- Implementing customer services
The Product Microservice manages product data, including:
- Defining product entities
- Setting up the product database
- Implementing CRUD operations for products
The Order Microservice is responsible for processing customer orders. Key steps include:
- Implementing the 'create order' method
- Handling exceptions
- Integrating with Kafka to manage order confirmations
The Payment Microservice manages payment transactions and communicates with the order service to complete order processing.
The Notification Microservice sends notifications to customers after successful order processing.
We will set up Kafka and Zookeeper using Docker, enabling asynchronous, event-driven communication between microservices.
Using Kafka, we’ll implement an order confirmation process, where the order service produces messages, and the notification service consumes them.
We'll implement an API Gateway that routes incoming requests to the appropriate microservices, handling cross-cutting concerns like authentication and logging.
Keycloak will be configured to secure the API Gateway and microservices. This involves:
- Setting up a Keycloak realm and client
- Configuring security for the API Gateway
- Testing the application to ensure security is correctly applied
Zipkin will be configured to trace requests across the microservices, helping us monitor and debug the application’s performance.
We'll set up centralized logging to monitor and troubleshoot issues across the application.
Finally, we'll test the full application flow, ensuring that all microservices work together seamlessly, with proper security, event handling, and service interactions.
This roadmap provides a complete guide to building a modern e-commerce web application using Domain-Driven Design (DDD) and microservices architecture. By following this guide, you'll gain practical experience with essential tools and concepts, laying a solid foundation for your future projects.