.NET Microservices – Full Course

Introduction

This tutorial provides a comprehensive guide on building microservices using .NET, based on the full course by Les Jackson. We will walk through the process of creating two microservices, implementing various patterns such as REST API and API Gateway, and deploying these services to a Kubernetes cluster. By the end of this guide, you will have a solid understanding of microservice architecture, data persistence, and messaging systems.

Step 1: Understand Microservices

• What are Microservices?

  • Microservices are an architectural style that structures an application as a collection of small, loosely coupled services.
  • Each service is responsible for a specific business capability and can be developed, deployed, and scaled independently.

• Benefits of Microservices

  • Flexibility in technology choices.
  • Ease of scaling individual components.
  • Improved fault isolation.

Step 2: Setup Your Development Environment

• Ingredients and Tooling
  • Ensure you have the following tools installed:
    • .NET SDK
    • Docker
    • Kubernetes (e.g., Minikube or Docker Desktop)
    • Insomnia (for API testing)
  • Download the free Kubernetes command and Architecture Cheat Sheet from the provided link.

Step 3: Build the First Microservice

• Scaffold the Service

  • Use the .NET CLI to create a new service:

    dotnet new webapi -n FirstService
    

• Implement the Data Layer

  • Model Creation: Define the data model.
  • DB Context: Set up the database context to manage entity objects.
  • Repository Pattern: Create a repository class for data access.

• Prepare the Database

  • Run migrations to create the database schema.

• Create Controller and Actions

  • Implement the controller with actions to handle API requests.

Step 4: Containerization with Docker

• Review Docker Concepts

  • Understand how Docker images and containers work.

• Containerize the Service

  • Create a Dockerfile in the project directory:

    FROM mcr.microsoft.com/dotnet/aspnet:6.0 AS base
    WORKDIR /app
    EXPOSE 80
    FROM mcr.microsoft.com/dotnet/sdk:6.0 AS build
    WORKDIR /src
    COPY ["FirstService/FirstService.csproj", "FirstService/"]
    RUN dotnet restore "FirstService/FirstService.csproj"
    COPY . .
    WORKDIR "/src/FirstService"
    RUN dotnet build "FirstService.csproj" -c Release -o /app/build
    FROM build AS publish
    RUN dotnet publish "FirstService.csproj" -c Release -o /app/publish
    FROM base AS final
    WORKDIR /app
    COPY --from=publish /app/publish .
    ENTRYPOINT ["dotnet", "FirstService.dll"]
    

• Push to Docker Hub

  • Build and push your Docker image to Docker Hub.

Step 5: Deploy to Kubernetes

• Introduction to Kubernetes

  • Understand the basic architecture and components of Kubernetes.

• Deploy the Service

  • Create a Kubernetes deployment and service YAML file.
  • Apply the configuration using:

    kubectl apply -f deployment.yaml
    

Step 6: Build the Second Microservice

• Scaffold the Second Service

  • Repeat the scaffolding process for the second microservice.

• Implement Synchronous Messaging

  • Use HTTP for direct communication between services.
  • Add a controller that will act as a client to the first service.

• Deploy the Second Service

  • Repeat the deployment process for the second service in the Kubernetes cluster.

Step 7: Implement SQL Server

• Add Persistent Volume Claim

  • Configure storage for SQL Server.

• Deploy SQL Server to Kubernetes

  • Create a deployment YAML for SQL Server.

• Update Services to Use SQL Server

  • Modify the database context in your services to connect to SQL Server.

Step 8: Introduce Message Bus with RabbitMQ

• Overview of RabbitMQ

  • Understand the role of RabbitMQ for asynchronous messaging.

• Deploy RabbitMQ to Kubernetes

  • Create a RabbitMQ deployment YAML file and apply it.

Step 9: Asynchronous Messaging Implementation

• Add Message Bus Publisher

  • Implement publishing functionality in your services.

• Testing the Publisher

  • Verify that messages are being sent and received.

Step 10: Implement gRPC

• Overview of gRPC

  • Learn about the benefits of using gRPC for service-to-service communication.

• Add gRPC Server and Client

  • Implement the gRPC server in the platform service and a client in the command service.

Conclusion

In this tutorial, we covered the fundamentals of building microservices using .NET, including setting up a development environment, creating and deploying services, and implementing messaging patterns. Each step builds upon the previous one, providing a robust framework for developing modern applications. As you proceed, consider exploring further into microservices patterns, security, and performance optimization. Happy coding!