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Building Serverless APIs with Azure Functions and .NET 8

#azure #dotnet #serverless #tutorial

Building Serverless APIs with Azure Functions and .NET 8

Introduction

Azure Functions combined with .NET 8 provides a powerful, scalable serverless platform for building APIs. In this tutorial, we will create a production-ready API from scratch.

Why Azure Functions?

  • Pay only for what you use - No idle costs
  • Auto-scale - Handles any load
  • .NET 8 support - Latest performance improvements
  • Easy deployment - GitHub Actions, VS Code, or CLI

Prerequisites

  • .NET 8 SDK
  • Azure Functions Core Tools
  • Azure subscription (free tier works)

Step 1: Create the Project 

# Create new Azure Functions project
func init MyApi --worker-runtime dotnet
cd MyApi
func new --name GetProducts --template "HTTP trigger" --authlevel function
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Step 2: Configure for .NET 8 

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>net8.0</TargetFramework>
    <AzureFunctionsVersion>v4</AzureFunctionsVersion>
  </PropertyGroup>
</Project>
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Step 3: Build a Product API

Model 

public class Product
{
    public int Id { get; set; }
    public string Name { get; set; }
    public decimal Price { get; set; }
    public string Category { get; set; }
}
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Function 

using Microsoft.Azure.Functions.Worker;
using Microsoft.Azure.Functions.Worker.Http;
using Microsoft.Extensions.Logging;

public class ProductFunctions
{
    private readonly ILogger<ProductFunctions> _logger;
    private static readonly List<Product> Products = new()
    {
        new Product { Id = 1, Name = "Azure Subscription", Price = 29.99m, Category = "Cloud" },
        new Product { Id = 2, Name = "DevOps Consulting", Price = 150.00m, Category = "Services" }
    };

    [Function("GetProducts")]
    public HttpResponseData GetProducts(
        [HttpTrigger(AuthorizationLevel.Function, "get", Route = "products")] HttpRequestData req)
    {
        var response = req.CreateResponse();
        response.WriteAsJsonAsync(Products);
        return response;
    }

    [Function("GetProductById")]
    public HttpResponseData GetProductById(
        [HttpTrigger(AuthorizationLevel.Function, "get", Route = "products/{id}")] HttpRequestData req,
        int id)
    {
        var product = Products.FirstOrDefault(p => p.Id == id);
        var response = req.CreateResponse();

        if (product == null)
        {
            response.StatusCode = System.Net.HttpStatusCode.NotFound;
        }
        else
        {
            response.WriteAsJsonAsync(product);
        }

        return response;
    }
}
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Step 4: Deploy to Azure 

# Login to Azure
az login

# Create function app
az functionapp create \n  --name my-dotnet-api \n  --resource-group my-rg \n  --storage-account mystorage123 \n  --consumption-plan-location eastus \n  --runtime dotnet-isolated

# Deploy
func azure functionapp publish my-dotnet-api
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Best Practices

  1. Use Dependency Injection - Cleaner code
  2. Configuration - Environment variables
  3. Logging - Application Insights

Monitoring

Azure Functions provides built-in monitoring:

  • Application Insights
  • Azure Monitor
  • Log Analytics

Conclusion

Azure Functions with .NET 8 is an excellent choice for building serverless APIs. Perfect for MVP-focused developers!

Azure #DotNET #Serverless #Tutorial #Microsoft

Top comments (1)

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nsdtattoo profile image
Rokeya sakhawat •

Great insights on building serverless APIs with Azure Functions and .NET 8. The combination offers excellent scalability, performance, and cost efficiency for modern cloud applications. I appreciate how this approach simplifies backend development while allowing developers to focus on writing clean, event-driven code without worrying about infrastructure management.