FeatureFlags.AdaptiveLogging 1.0.2

FeatureFlags.AdaptiveLogging

A lightweight helper for feature‑flag–driven, adaptive logging powered by Azure App Configuration. It:

• Wires Feature Flags from configuration via AddFeatureFlagsFromConfiguration().
• Registers services via AddFeatureFlagDrivenLogging().
• Uses a single refresh knob AppConfig:RefreshInSeconds for both the Feature Flags SDK refresh window ( UseFeatureFlags().SetRefreshInterval(...)) and a local non‑blocking TryRefreshAsync throttle—keeping evaluation cadence consistent.
• When the flag is ON, ensures Debug/Trace diagnostics are visible. If the provider would drop them, the helper * elevates* them to Information and prefixes "[FORCED-<LEVEL>]" so you can spot them in production.
• Provides automatic correlation: if you don’t pass a requestId, a GUID (format N) is generated and all messages from that FeatureLogger instance are prefixed with the same id.

1) Required settings

{
  "AppConfig": {
    "ConnectionString": "Endpoint=...;Id=...;Secret=...",
    "Label": "dev|ProjectX",
    "RefreshInSeconds": 5
  },
  "Logging": { "LogLevel": { "Default": "Information" } }
}

2) Create flags and labels

• Create your flag (e.g., LogEndpointA) in App Configuration Feature Manager.
• Use Label for environment and/or project scoping (e.g., dev|WebApi, stg|WorkerA).

3) Cost & performance

• Lower AI costs via host.json levels and sampling; Debug appears only when the flag is ON.
• Unified refresh avoids drift and excessive calls.

4) Install & wire

dotnet add package FeatureFlags.AdaptiveLogging

builder.Configuration.AddFeatureFlagsFromConfiguration();
builder.Services.AddFeatureFlagDrivenLogging();

5) From zero in App Configuration

1. Create the App Configuration resource.
2. Add LogEndpointA (and label variants if needed).
3. Set AppConfig:* in your app settings.

6) Quick recipes (pseudo‑code only)

6.1 .NET 8 Console

var cfg = new ConfigurationBuilder()
  .AddJsonFile("appsettings.json", false, true)
  .AddEnvironmentVariables()
  .Build();

cfg.AddFeatureFlagsFromConfiguration();

var services = new ServiceCollection();
services.AddLogging(b => b.AddConsole().SetMinimumLevel(LogLevel.Information));
services.AddFeatureFlagDrivenLogging();
services.AddSingleton<IConfiguration>(cfg);

var sp = services.BuildServiceProvider();
var logger = sp.GetRequiredService<ILoggerFactory>().CreateLogger("Console");

var flogger = await logger.EnableDebugAsync("LogEndpointA");
flogger.LogInformation("Console says hi");
flogger.LogDebug("More details (visible when flag is ON)");

6.2 .NET 8 Minimal API

var builder = WebApplication.CreateBuilder(args);

builder.Configuration.AddFeatureFlagsFromConfiguration();
builder.Services.AddFeatureFlagDrivenLogging();
builder.Services.AddControllers();

var app = builder.Build();

public class WeatherController : ControllerBase
{
    private readonly ILogger<WeatherController> _logger;
    public WeatherController(ILogger<WeatherController> logger) => _logger = logger;

    [HttpGet("/api/weather")]
    public async Task<IActionResult> Get()
    {
        var flogger = await _logger.EnableDebugAsync("LogEndpointA");
        flogger.LogInformation("Weather endpoint hit");
        flogger.LogDebug("Debug when flag is ON");
        return Ok(new { ok = true });
    }
}

6.3 .NET 10 Minimal API

var builder = WebApplication.CreateBuilder(args);

builder.Configuration.AddFeatureFlagsFromConfiguration();
builder.Services.AddFeatureFlagDrivenLogging();
builder.Services.AddControllers();

var app = builder.Build();

app.MapGet("/api/info", async (ILogger<Program> logger) =>
{
    var flogger = await logger.EnableDebugAsync("LogEndpointA");
    flogger.LogInformation(".NET 10 endpoint");
    flogger.LogDebug("Debug when flag is ON");
    return Results.Ok(new { ok = true });
});

6.4 Azure Functions v4 – in‑process (.NET 8)

public override void ConfigureAppConfiguration(b)
  => b.ConfigurationBuilder.AddFeatureFlagsFromConfiguration();

public override void Configure(h)
  => h.Services.AddFeatureFlagDrivenLogging();

public class Function1
{
    private readonly ILogger<Function1> _logger;
    public Function1(ILogger<Function1> logger) => _logger = logger;

    [FunctionName("Function1")]
    public async Task Run([QueueTrigger("demo-queue")] string msg)
    {
        var flogger = await _logger.EnableDebugAsync("LogEndpointA");
        flogger.LogInformation("Processing {Msg}", msg);
        flogger.LogDebug("Debug when flag is ON");
    }
}

6.5 Azure Functions v4 – isolated (.NET 8)

var host = new HostBuilder()
  .ConfigureAppConfiguration((ctx, cfg) => cfg.AddFeatureFlagsFromConfiguration())
  .ConfigureFunctionsWorkerDefaults()
  .ConfigureServices(s => s.AddFeatureFlagDrivenLogging())
  .Build();

public class QueueProcessor
{
    private readonly ILogger<QueueProcessor> _logger;
    public QueueProcessor(ILogger<QueueProcessor> logger) => _logger = logger;

    [Function("QueueProcessor")]
    public async Task Run([QueueTrigger("demo-queue")] string msg)
    {
        var flogger = await _logger.EnableDebugAsync("LogEndpointA");
        flogger.LogInformation("[Isolated] Processing {Msg}", msg);
        flogger.LogDebug("[Isolated] Debug when flag is ON");
    }
}

6.6 .NET Framework 4.7.2 (OWIN)

var cfg = new ConfigurationBuilder()
  .AddJsonFile("appsettings.json", false, true)
  .AddEnvironmentVariables()
  .Build();

cfg.AddFeatureFlagsFromConfiguration();

var services = new ServiceCollection();
services.AddLogging(b => b.AddConsole().SetMinimumLevel(LogLevel.Information));
services.AddFeatureFlagDrivenLogging();
services.AddSingleton<IConfiguration>(cfg);

var sp = services.BuildServiceProvider();

public class SampleController : ApiController
{
    private readonly ILogger _logger = Program.Services
        .GetRequiredService<ILoggerFactory>()
        .CreateLogger("Sample");

    [HttpGet, Route("api/sample")]
    public async Task<IHttpActionResult> Get()
    {
        var flogger = await _logger.EnableDebugAsync("LogEndpointA");
        flogger.LogInformation("Framework endpoint");
        flogger.LogDebug("Debug when flag is ON");
        return Ok(new { ok = true });
    }
}

6.7 Azure Functions – Queue trigger (Service Bus)

// In-process startup wiring (once at startup)
public override void ConfigureAppConfiguration(builder)
    => builder.ConfigurationBuilder.AddFeatureFlagsFromConfiguration();

public override void Configure(services)
    => services.Services.AddFeatureFlagDrivenLogging();

// Function class (Service Bus trigger)
public class QueueProcessor
{
    private readonly ILogger<QueueProcessor> _logger;
    public QueueProcessor(ILogger<QueueProcessor> logger) => _logger = logger;

    [FunctionName("QueueProcessor")]
    public async Task Run(
        [ServiceBusTrigger("your-queue-name", Connection = "ServiceBus:Connection")] string message,
        int deliveryCount)
    {
        var flogger = await _logger.EnableDebugAsync("LogEndpointA");
        flogger.LogInformation("SB message received. DeliveryCount={DeliveryCount}", deliveryCount);
        flogger.LogDebug("Raw payload: {Message}", message);
        // ... business logic ...
        flogger.LogInformation("SB message processed at {UtcNow}", DateTime.UtcNow);
    }
}

// appsettings.json (pseudo-config)
{
  "ServiceBus": {
    "Connection": "Endpoint=sb://<namespace>.servicebus.windows.net/;SharedAccessKeyName=...;SharedAccessKey=..."
  },
  "AppConfig": {
    "ConnectionString": "Endpoint=...;Id=...;Secret=...",
    "Label": "dev|ProjectX",
    "RefreshInSeconds": 5
  },
  "Logging": { "LogLevel": { "Default": "Information" } }
}

7) Application Insights Kusto (KQL) cheat‑sheet

• Latest logs:

traces | where timestamp > ago(30m) | order by timestamp desc

• Elevated debug lines:

traces | where timestamp > ago(2h) | where message has "[FORCED-DEBUG]" or message has "[FORCED-Trace]"

• Filter by your request/correlation id:

let rid = "a3f2e6d9f81e4e9e9f6b2d3f4c5a6b7c";
traces | where timestamp > ago(1d) | where message startswith strcat("[", rid, "] ")

• Volume/severity distribution:

traces | where timestamp > ago(24h) | summarize count() by severityLevel | order by severityLevel asc

8) Changelog (high‑level)

• Automatic correlation id when not provided.
• Unified refresh interval for SDK and local throttle.