Microservices

Microservices

This page details each microservice in the Cloud-Native E-commerce Platform, their responsibilities, and how they interact.

Microservices Overview

Our platform is composed of several microservices, each responsible for a specific business domain. All services follow Clean Architecture principles with clear separation of concerns.

Frontend Microfrontends (React + Nx)

• Host Shell (4200): Runtime composition and auth bootstrap
• Store (4201): Product browsing; uses updated product APIs and shared layout
• Checkout (4202): Cart/checkout flow; simplified product/checkout logic and API alignment
• Account (4203): User profile and auth-aware views
• Admin (4204): Product/admin management; includes activity tracking and S3 upload support
• Shared packages: @ecommerce-platform/auth-provider, @ecommerce-platform/app-injector, @ecommerce-platform/shared-layout
• Routing: TanStack Router across host/remotes

New/Updated Backend Capabilities (Last 3 Months)

• S3 image storage with LocalStack-first migration scripts for product media
• Service access portal (./access-services.sh) with smarter namespace/service detection and updated ports
• Istio & HTTPS/OIDC enhancements baked into deployment scripts
• k6 load testing integrated with Prometheus scrape config and Grafana dashboards
• Checkout/Basket: Updated endpoints and username resolution logic; improved error handling/logging

Catalog Service

Purpose

Manages the product catalog, including products, categories, and brands.

Components

• Catalog.API: REST API endpoints for catalog operations
• Catalog.Application: Application business logic using CQRS pattern
• Catalog.Core: Domain entities and business rules
• Catalog.Infrastructure: MongoDB data access implementation

Key Features

• Product CRUD operations
• Category and brand management
• Product search and filtering
• Product image handling

Data Storage

• MongoDB: Document database for flexible product attributes

API Endpoints

• GET /api/v1/catalog/products: Get all products
• GET /api/v1/catalog/products/{id}: Get product by ID
• GET /api/v1/catalog/products/category/{category}: Get products by category
• POST /api/v1/catalog/products: Create new product
• PUT /api/v1/catalog/products: Update existing product
• DELETE /api/v1/catalog/products/{id}: Delete product

Basket Service

Purpose

Manages shopping carts for users, including adding/removing items and checkout.

Components

• Basket.API: REST API endpoints for basket operations
• Basket.Application: Application business logic
• Basket.Core: Domain entities and business rules
• Basket.Infrastructure: Redis data access implementation

Key Features

• Shopping cart creation and management
• Add/remove/update cart items
• Cart checkout process
• Integration with Discount service for applying discounts

Data Storage

• Redis: In-memory database for fast cart operations

API Endpoints

• GET /api/v1/basket/{username}: Get basket by username
• POST /api/v1/basket: Update basket
• DELETE /api/v1/basket/{username}: Delete basket
• POST /api/v1/basket/checkout: Checkout basket

Discount Service

Purpose

Manages product discounts and coupon codes.

Components

• Discount.API: REST API and gRPC service for discount operations
• Discount.Application: Application business logic
• Discount.Core: Domain entities and business rules
• Discount.Infrastructure: PostgreSQL data access implementation

Key Features

• Discount CRUD operations
• Coupon validation
• Discount calculation
• gRPC service for internal communication

Data Storage

• PostgreSQL: Relational database for discount rules

API Endpoints

• GET /api/v1/discount/{productName}: Get discount by product name
• POST /api/v1/discount: Create discount
• PUT /api/v1/discount: Update discount
• DELETE /api/v1/discount/{productName}: Delete discount

gRPC Services

• GetDiscount: Get discount for product
• CreateDiscount: Create new discount
• UpdateDiscount: Update existing discount
• DeleteDiscount: Delete discount

Ordering Service

Purpose

Manages the order process from creation to fulfillment.

Components

• Ordering.API: REST API endpoints for order operations
• Ordering.Application: Application business logic using CQRS with MediatR
• Ordering.Core: Domain entities and business rules
• Ordering.Infrastructure: SQL Server data access implementation

Key Features

• Order creation and management
• Order status tracking
• Order history for users
• Event-driven integration with Basket service

Data Storage

• SQL Server: Relational database for order data

API Endpoints

• GET /api/v1/orders: Get all orders
• GET /api/v1/orders/{username}: Get orders by username
• POST /api/v1/orders: Create order
• PUT /api/v1/orders: Update order
• DELETE /api/v1/orders/{id}: Delete order

Event Consumers

• BasketCheckoutConsumer: Consumes basket checkout events from RabbitMQ

API Gateway

Purpose

Serves as the entry point for all client requests, routing them to appropriate microservices.

Components

• Ocelot.ApiGateway: API Gateway implementation using Ocelot

Key Features

• Request routing
• Request aggregation
• Authentication and authorization
• Rate limiting and caching
• Load balancing

Configuration

• Route configuration in ocelot.json
• Environment-specific configurations

Service Communication

Synchronous Communication

• REST APIs: For direct service-to-service communication
• gRPC: For high-performance internal communication (Basket to Discount)

Asynchronous Communication

• RabbitMQ: For event-driven communication
• Event Bus: Shared infrastructure for publishing and consuming events

Events

• BasketCheckoutEvent: Published when a user checks out their basket
• OrderCreatedEvent: Published when an order is created

Service Dependencies

• Basket Service → Discount Service: Gets product discounts via gRPC
• Basket Service → Ordering Service: Sends checkout events via RabbitMQ
• All Services → API Gateway: All client communication goes through the gateway