A Simple Analogy

Azure App Configuration is like a master control panel. Instead of scattered switches throughout a building, all controls are in one place. You can flip switches (feature flags), adjust dials (settings), and see everything at once without restarting the building.

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What Is Azure App Configuration?

Azure App Configuration is a service that centralizes application settings and feature flags. It lets you manage configuration without redeploying code, enabling dynamic updates and A/B testing.

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Why Use App Configuration?

• Centralized management: All settings in one place
• Dynamic updates: Change settings without redeploying
• Feature flags: Gradually roll out features
• Environment separation: Different configs for dev/staging/prod
• Version control: Track configuration history
• Integration: Works with Key Vault for secrets

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Core Concepts

| Concept | Purpose | |---------|---------| | Key-Values | Simple configuration settings | | Feature Flags | Toggle features on/off dynamically | | Environments | Separate configs per deployment stage |

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ASP.NET Core Setup

var builder = WebApplication.CreateBuilder(args);

// Add App Configuration
var settings = builder.Configuration;
var appConfigConnection = settings["AppConfig:Connection"];

builder.Configuration.AddAzureAppConfiguration(options =>
{
    options.Connect(appConfigConnection)
        .ConfigureKeyVaultSecrets(c => 
            c.SetCredential(new DefaultAzureCredential()));
});

var app = builder.Build();

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Using Key-Values

// In appsettings.json or App Configuration:
{
  "AppName": "MyApp",
  "Features:NewDashboard": "true",
  "Logging:Level": "Information"
}

// In code:
public class HomeController : ControllerBase
{
    private readonly IConfiguration _config;
    
    public HomeController(IConfiguration config)
    {
        _config = config;
    }
    
    public string GetSettings()
    {
        var appName = _config["AppName"];
        var level = _config["Logging:Level"];
        return $"{appName} - {level}";
    }
}

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Feature Flags

// Define feature flags
public enum Features
{
    NewCheckout,
    BetaDashboard,
    AnalyticsV2
}

public class FeatureService
{
    private readonly IFeatureManager _featureManager;
    
    public FeatureService(IFeatureManager featureManager)
    {
        _featureManager = featureManager;
    }
    
    public async Task<bool> IsFeatureEnabledAsync(Features feature)
    {
        return await _featureManager.IsEnabledAsync(feature.ToString());
    }
}

// Usage
if (await featureService.IsFeatureEnabledAsync(Features.NewCheckout))
{
    // Show new checkout flow
}

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Real-World Scenario

// A/B testing new feature
var isNewUiEnabled = await _config.IsEnabledAsync("UI:NewVersion");

if (isNewUiEnabled)
{
    return View("NewCheckout.cshtml");
}
return View("LegacyCheckout.cshtml");

// Later: Enable for 50% of users, then 100%, then disable
// No code changes, no redeployment

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Related Concepts to Explore

• Feature Management library
• Integration with Key Vault
• Configuration inheritance and overrides
• JSON configuration files

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Summary

Azure App Configuration enables dynamic configuration management and feature flags without code changes. Use it to decouple settings from deployments and gradually roll out features with confidence.