ProductService

Simple ASP.NET Core Web API for managing products using a Clean Architecture approach.

Tech Stack

• .NET 8
• ASP.NET Core Web API
• Dapper
• PostgreSQL
• xUnit
• Docker

Project Structure

ProductService.sln
src/
  ProductService.API/
    Controllers/
    HealthChecks/
    Program.cs
    ProductService.API.csproj
  ProductService.Application/
    Interfaces/
    Services/
    ProductService.Application.csproj
  ProductService.Domain/
    Entities/
    ProductService.Domain.csproj
  ProductService.Infrastructure/
    Repositories/
    ProductService.Infrastructure.csproj
tests/
  ProductService.Application.Tests/
Dockerfile
docker-compose.yml

Architecture Overview

This project is split into 4 layers:

• ProductService.Domain Contains the core application entity, such as Product.
• ProductService.Application Contains business logic and abstractions, such as IProductRepository and ProductService.
• ProductService.Infrastructure Contains the PostgreSQL data access implementation using Dapper.
• ProductService.API Contains controllers, health checks, dependency injection, and application startup.

Request flow:

1. The request enters a controller in the API layer.
2. The controller calls a service in the Application layer.
3. The service uses a repository interface instead of a direct implementation.
4. The actual repository implementation lives in the Infrastructure layer.
5. Core entities remain in the Domain layer.

Features

• CRUD product
• Health check endpoint
• Docker support
• Structured logging with Serilog
• Elasticsearch log shipping
• Elastic APM tracing
• Unit tests for the application layer

API Endpoints

Health Check

• GET /health

Products

• GET /api/products
• GET /api/products/{id}
• POST /api/products
• PUT /api/products/{id}
• DELETE /api/products/{id}

Example Request Body

For POST /api/products or PUT /api/products/{id}:

{
  "name": "ASUS Laptop",
  "description": "Laptop for development work",
  "price": 15000000,
  "stock": 10
}

Running Locally

Make sure .NET 8 SDK is installed.

dotnet restore ProductService.sln
dotnet build ProductService.sln
dotnet run --project src/ProductService.API/ProductService.API.csproj

The default development URL usually follows launchSettings.json. If you want to set it explicitly:

dotnet run --project src/ProductService.API/ProductService.API.csproj --urls http://localhost:8080

Database Configuration

The connection string is read from the ConnectionStrings:Postgres key.

Example format:

Host=localhost;Port=5432;Database=productdb;Username=postgres;Password=postgres

Configuration files:

• src/ProductService.API/appsettings.json
• src/ProductService.API/appsettings.Development.json

Running With Docker

Build the API image:

docker build -t product-service .

Run with compose:

docker compose up --build

Notes:

• docker-compose.yml only runs the API service.
• The API still uses a PostgreSQL instance that is assumed to already exist on the external Docker network local_network.
• The container connection string is provided through the ConnectionStrings__Postgres environment variable in docker-compose.yml.
• The Elasticsearch sink target is provided through Serilog__WriteTo__1__Args__nodes__0.
• The Elastic APM Server endpoint is provided through ElasticApm__ServerUrl.

Logging

The API uses Serilog for structured logging.

• Request logs are written through UseSerilogRequestLogging().
• Application and repository logs are written through injected ILogger<T>.
• Logs are sent to both the console and Elasticsearch.
• API request duration is emitted in the request log event.
• Database execution duration is emitted in repository log events.

Default Elasticsearch endpoint:

http://localhost:9200

Important log fields:

• TransactionId
• Operation
• Layer
• TraceId
• SpanId
• ApiResponseTimeMs
• DurationMs
• DbSystem
• DbOperation
• Table

Elastic APM

The API is instrumented with the Elastic APM .NET agent.

• APM Server default endpoint: http://localhost:8200
• Service name: product-service-api
• Main configuration key: ElasticApm

Docker environment variables:

• ELASTICSEARCH_URL
• ELASTIC_APM_SERVER_URL

Request correlation:

• Response header: X-Transaction-Id
• Log field: TransactionId
• If X-Transaction-Id is provided by the client, the API reuses it.
• If it is not provided, the API generates a random 7-digit value per request.

Running Tests

dotnet test ProductService.sln

The current tests focus on the application layer:

• returning all products
• returning a product by id
• assigning Id and CreatedAt during product creation
• passing updated product data to the repository
• passing the product id to the repository for deletion

Postman Collection

The Postman collection is available at:

• ProductService.postman_collection.json

Import that file into Postman and update the baseUrl variable if needed.

Notes

• The health check endpoint is available at /health.
• Swagger is enabled when the environment is Development.
• The repository uses Dapper with direct SQL queries against the products table.