Clean Architecture Sample Project

This repository contains a sample project demonstrating Clean Architecture principles in a .NET application. It incorporates various modern development tools and practices, including OpenTelemetry, Jaeger, Prometheus, Loki, MediatR, Fluent Validation, Domain-driven design (DDD), and Test-driven design (TDD). The project also includes unit tests, integration tests, and functional tests, all running in a fully containerized environment using Docker.

Project Structure

The project follows a layered architecture with a focus on separation of concerns and scalability:

Source Code (src Directory)

• Use Case Layer: Contains core business logic, MediatR handlers, and Fluent Validation validators.
• Core Layer: Implements domain models and business rules following Domain-Driven Design principles.
• Infrastructure Layer: Handles external dependencies such as database access and third-party integrations.
• Web Layer: Provides the REST API endpoints and OpenTelemetry instrumentation for request tracing and logging.

Tests (tests Directory)

• Unit Tests: Test the smallest units of code in isolation.
• Integration Tests: Verify the interactions between multiple components (e.g., database access).
• Functional Tests: Simulate real-world usage scenarios by testing the application end-to-end.

Features

Clean Architecture Principles

• Strict separation of concerns across layers.
• Dependency inversion to keep the core domain independent of external frameworks.
• Well-defined boundaries between layers.

Observability

• OpenTelemetry: Integrated for distributed tracing and metrics collection.
• Jaeger: Displays tracing information for debugging and performance analysis.
• Prometheus: Collects application metrics.
• Loki: Stores and queries logs.

Validation

• FluentValidation: Centralized and extensible validation framework for request and business rule validation.

Messaging and CQRS

• MediatR: Implements the Command-Query Responsibility Segregation (CQRS) pattern for managing commands and queries.

Dockerized Environment

• Fully containerized setup using Docker Compose.
• Includes all necessary services for the application: MongoDB, OpenTelemetry Collector, Jaeger, Prometheus, Loki, and Grafana.

Additional Highlights

• .NET 9: Built with the latest .NET version for cutting-edge features.
• api.http: Provides API testing scripts for quick validation.
• TestContainers: Simplifies running integration tests and functional tests with containers.

Getting Started

Prerequisites

• .NET 9
• Docker

Running the Application

1. Clone the repository:

   git clone <repo-url>
   cd <repo-directory>

2. Create a .env file in the src/CSharpSampleCRUDTest.CleanArch.Web directory with the following content:

   MONGODB_CONNECTION_STRING=mongodb://mongodb:27017
   MONGODB_DATABASE_NAME=SampleDb
   MONGODB_COLLECTION_NAME=Customer
   
   COLLECTOR=http://otel-collector:4317
   LOKI=http://loki:3100

3. Start the application and its dependencies using Docker Compose:

   docker-compose up --build

4. Access the application:
   • Jaeger UI: http://localhost:16686
   • Prometheus: http://localhost:9090
   • Grafana: http://localhost:3000 (Default credentials: admin/admin)

Running Tests

1. Navigate to the tests directory.
2. Create a .env file in the tests/CSharpSampleCRUDTest.CleanArch.FunctionalTests directory with the following content:

   MONGODB_CONNECTION_STRING=mongodb://localhost:27018 
   MONGODB_DATABASE_NAME=SampleTestDb
   MONGODB_COLLECTION_NAME=CustomerEntity
   API_BASE_ADDRESS=http://localhost:57679
   
   COLLECTOR=http://otel-collector:4317
   LOKI=http://loki:3100

3. Run the unit, integration, or functional tests:

   dotnet test

Configuration

OpenTelemetry Configuration

The OpenTelemetry Collector (otel-collector) is configured using otel-collector-config.yaml. Update this file to customize the receivers, processors, and exporters.

Prometheus Configuration

Prometheus is configured using prometheus.yml. Add or modify scrape jobs as needed to monitor additional services.

Loki Configuration

Loki is configured via loki-config.yaml. Update storage and schema settings as required.

Key Dependencies

• OpenTelemetry: For tracing and metrics.
• Jaeger: Distributed tracing visualization.
• Prometheus: Metrics collection.
• Loki: Centralized logging.
• MongoDB: NoSQL database for application data.
• MediatR: Implements CQRS pattern.
• FluentValidation: Validates inputs and business rules.
• TestContainers: Simplifies containerized integration tests and functional tests.

Contribution

Contributions are welcome! Please fork the repository and submit a pull request.

---

Feel free to reach out with any questions or feedback. Happy coding!