A Simple Analogy

Azure App Service is like renting a house instead of building one. You don't manage the foundation (servers, OS, runtime)—Azure handles that. You just run your app and pay for what you use.

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What Is Azure App Service?

App Service is a Platform-as-a-Service (PaaS) for hosting web apps, APIs, and mobile backends. It handles infrastructure, scaling, and patching automatically.

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Benefits

• No infrastructure management: Focus on code
• Auto-scaling: Handle traffic spikes automatically
• Built-in CI/CD: Deploy from GitHub, Azure DevOps
• Monitoring: Application Insights integration
• Cost-effective: Pay-as-you-go pricing

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Deployment from .NET Project

// In Program.cs
var builder = WebApplication.CreateBuilder(args);

builder.Services.AddControllers();
builder.Services.AddApplicationInsightsTelemetry();

var app = builder.Build();
app.UseHttpsRedirection();
app.MapControllers();
app.Run();

Deploy with Azure CLI:

az webapp create --resource-group myGroup \
  --plan myServicePlan \
  --name myApp
  
dotnet publish -c Release
az webapp deployment source config-zip \
  --resource-group myGroup \
  --name myApp \
  --src publish.zip

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Configuration & Secrets

// Access App Service settings
var connectionString = builder.Configuration["ConnectionStrings:Default"];
var apiKey = builder.Configuration["ApiKey"];

// From Azure Key Vault
builder.Configuration.AddAzureKeyVault(
    new Uri($"https://{keyVaultName}.vault.azure.net/"),
    new DefaultAzureCredential());

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Scaling

# Scale up (increase machine size)
az appservice plan update --name myPlan \
  --resource-group myGroup \
  --sku P1V2

# Scale out (add instances)
az appservice plan update --name myPlan \
  --resource-group myGroup \
  --number-of-workers 3

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Monitoring

public class HealthCheckController : ControllerBase
{
    [HttpGet("/health")]
    public IActionResult Health()
    {
        return Ok(new { status = "healthy" });
    }
}

// App Service can use this for health checks

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Best Practices

1. Use deployment slots: Test before production
2. Enable authentication: Azure AD integration
3. Monitor performance: Application Insights
4. Auto-scale rules: Scale based on CPU/memory
5. Database connections: Use Connection Strings

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Related Concepts

• Application Insights monitoring
• Deployment slots for staging
• Azure SQL Database integration
• Application gateway for load balancing

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Summary

Azure App Service simplifies ASP.NET Core deployment with automatic scaling, monitoring, and built-in DevOps. Focus on building features while Azure handles infrastructure.