EcommerceMicroservices

E-Commerce Microservices (RabbitMQ) — Critter Stack Conversion

See also: EcommerceModularMonolith/ — the same domain collapsed into a single application with durable local queues.

Original Project

Repository: aspnetrun/run-aspnetcore-microservices License: MIT Stack: ASP.NET Core 8, MediatR, MassTransit (RabbitMQ), Carter, EF Core (SQL Server), Marten (Catalog & Basket), gRPC (Discount), Redis, MongoDB, YARP API Gateway

A full e-commerce microservices application with 4 services, API gateway, and Razor Pages web app. The most compelling migration target in the inventory because it already uses Marten in two services.

What Changed

Architecture

Aspect	Original	Converted
Projects	12 (4 services × layers + BuildingBlocks + Gateway + WebApp)	5 (4 services + Shared)
Ordering service	4 projects (API, Application, Domain, Infrastructure)	1 project
Databases	PostgreSQL + SQL Server + SQLite + Redis + MongoDB	PostgreSQL only (Marten)
Message bus	MassTransit + RabbitMQ	Wolverine cascading messages (+ RabbitMQ when needed)
CQRS dispatch	MediatR + pipeline behaviors	Wolverine handlers (direct)
Discount transport	gRPC + Protocol Buffers	Wolverine.HTTP (plain REST)
API Gateway	YARP reverse proxy	Removed (each service is independently deployable)

Per-Service Changes

Catalog (was ~15 files across handlers + endpoints):

• Already used Marten — kept as-is
• Replaced 6 MediatR handlers + 6 Carter endpoints with 6 Wolverine endpoints
• Added [Entity] for get-by-id, update, delete operations
• Now 5 files

Basket (was ~12 files + Redis caching layer):

• Already used Marten — kept as-is
• Replaced MediatR handlers + MassTransit publisher with Wolverine endpoints
• CheckoutBasket uses cascading message tuple (bool, BasketCheckoutEvent) instead of IPublishEndpoint
• Removed IBasketRepository / CachedBasketRepository decorator — direct Marten session
• Now 5 files

Ordering (was 4 projects, ~40 files with DDD + Clean Architecture):

• Collapsed Domain + Application + Infrastructure + API into 1 project
• Replaced EF Core (SQL Server) with Marten (PostgreSQL)
• Replaced DDD ValueObjects (OrderId, CustomerId, Address, Payment) with flat document properties
• Replaced MassTransit IConsumer<BasketCheckoutEvent> with Wolverine handler
• Eliminated: AuditableEntityInterceptor, DispatchDomainEventsInterceptor, 4 EF configurations, DbUp migrations
• Now 6 files

Discount (was gRPC service with Protocol Buffers):

• Replaced gRPC + Mapster + EF Core (SQLite) with Wolverine.HTTP + Marten
• Now 4 files

Removed Entirely

• BuildingBlocks — MediatR CQRS interfaces, validation behavior, logging behavior, MassTransit extensions
• YARP API Gateway — rate limiting, reverse proxy configuration
• Shopping.Web — Razor Pages frontend with Refit HTTP clients
• Redis — caching layer for basket
• MongoDB — not used in the original (was in earlier versions)

What Stays the Same

• Domain concepts: Products, Shopping Carts, Orders, Coupons
• Service boundaries: Catalog, Basket, Ordering, Discount
• Integration event flow: Basket checkout → Order creation
• REST API contracts (same routes, same payloads)

Running

Requires PostgreSQL. Each service needs its own database. Configure connection strings in each service's appsettings.json, then run each service independently:

cd Catalog && dotnet run
cd Basket && dotnet run
cd Ordering && dotnet run
cd Discount && dotnet run

Each service has Swagger UI at /swagger.