.NET Core Microservices Reference

Overview

Microservices are a collection of small, autonomous services that work together to build a complex application. .NET Core provides a robust platform for creating, deploying, and managing microservices.

• Lightweight and cross‑platform
• Built‑in dependency injection
• Support for containers and orchestration

Architecture

Design principles for a resilient microservice architecture:

1. Domain‑driven design (DDD)
2. Bounded contexts
3. Event‑driven communication
4. Stateless services

public class OrderService : IOrderService
{
    private readonly IEventBus _eventBus;
    public OrderService(IEventBus eventBus) => _eventBus = eventBus;
    // ...
}

Communication

Common patterns for inter‑service communication:

• RESTful HTTP APIs (ASP.NET Core MVC)
• gRPC for high‑performance contracts
• Message queues (RabbitMQ, Azure Service Bus)
• Event sourcing and streaming (Kafka)

Data Management

Each microservice should own its data store. Recommendations:

• Relational DB: EF Core with migrations
• NoSQL: Cosmos DB, MongoDB
• Cache: Redis

services.AddDbContext<OrderContext>(options =>
    options.UseSqlServer(configuration.GetConnectionString("OrderDB")));
// Cache
services.AddStackExchangeRedisCache(opts => {
    opts.Configuration = configuration["Redis:ConnectionString"];
});

Security

Secure microservices using:

• IdentityServer4 / Duende Identity Server
• JWT bearer tokens
• OAuth2 & OpenID Connect
• Transport security (HTTPS)

services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
    .AddJwtBearer(options => {
        options.Authority = "https://auth.example.com/";
        options.Audience = "microservice-api";
    });

Deployment

Containerize services with Docker and orchestrate with Kubernetes:

# Dockerfile
FROM mcr.microsoft.com/dotnet/aspnet:8.0 AS base
WORKDIR /app
EXPOSE 80

FROM mcr.microsoft.com/dotnet/sdk:8.0 AS build
WORKDIR /src
COPY ["MyService/MyService.csproj", "MyService/"]
RUN dotnet restore "MyService/MyService.csproj"
COPY . .
WORKDIR "/src/MyService"
RUN dotnet build "MyService.csproj" -c Release -o /app/build

FROM build AS publish
RUN dotnet publish "MyService.csproj" -c Release -o /app/publish

FROM base AS final
WORKDIR /app
COPY --from=publish /app/publish .
ENTRYPOINT ["dotnet", "MyService.dll"]

API Reference

Explore the public API surface of the microservice framework:

• IMicroserviceBuilder
• INotificationService
• IEventBus