📈 Telemetry & Observability

Configure OpenTelemetry in Program.cs

using OpenTelemetry.Resources;
using OpenTelemetry.Trace;
using WebSpark.HttpClientUtility.RequestResult;

// Add OpenTelemetry with tracing
builder.Services.AddOpenTelemetry()
  .WithTracing(tracerBuilder =>
  {
        tracerBuilder
    .SetResourceBuilder(ResourceBuilder.CreateDefault()
    .AddService("WebSpark.HttpClientUtility.Demo", "1.0.0"))
     .AddSource("WebSpark.HttpClientUtility")
    .AddHttpClientInstrumentation()
            .AddAspNetCoreInstrumentation()
            .AddConsoleExporter();  // For dev/debugging
            // .AddJaegerExporter();   // For Jaeger
  // .AddOtlpExporter(); // For OTLP-compatible backends
 });

// Register the telemetry decorator
builder.Services.AddScoped<IHttpRequestResultService>(provider =>
{
    IHttpRequestResultService service = 
        provider.GetRequiredService<HttpRequestResultService>();
    
    // Wrap with telemetry decorator (outermost layer)
    service = new HttpRequestResultServiceTelemetry(
        provider.GetRequiredService<ILogger<HttpRequestResultServiceTelemetry>>(),
        service
    );
    
    return service;
});

Using Telemetry in Your Service

public class MyApiService
{
    private readonly IHttpRequestResultService _requestService;
    private readonly ILogger<MyApiService> _logger;
    
    public async Task<MyData?> GetDataWithTelemetryAsync(string id)
    {
      // Create request with debug enabled for detailed logging
var request = new HttpRequestResult<MyData>
        {
      RequestPath = $"https://api.example.com/data/{id}",
   RequestMethod = HttpMethod.Get,
  IsDebugEnabled = true  // Enable detailed telemetry
      };
   
        // Execute - telemetry is automatic
    var result = await _requestService.HttpSendRequestResultAsync(request);
        
// Access telemetry data
        _logger.LogInformation(
            "Request completed: CorrelationId={CorrelationId}, " +
        "Duration={Duration}ms, Status={Status}",
 result.CorrelationId,
            result.RequestDurationMilliseconds,
 result.StatusCode);
        
     // Additional context is available in RequestContext dictionary
      if (result.RequestContext.TryGetValue("ActivityId", out var activityId))
        {
     _logger.LogDebug("Activity ID: {ActivityId}", activityId);
     }
        
    return result.ResponseResults;
    }
}

Querying Telemetry Data

// Example: Search logs by correlation ID
// All logs for a request share the same correlation ID
// In your logging platform (e.g., Application Insights, Elasticsearch):

{
  "timestamp": "2025-01-08T10:30:45.123Z",
  "level": "Information",
  "message": "HTTP Request: GET https://v2.jokeapi.dev/joke/Programming",
  "correlationId": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
  "requestDuration": 245,
  "statusCode": 200
}

// Track the entire request flow using the correlation ID:
// 1. Request initiated
// 2. External API call
// 3. Response received
// 4. Data processed
// 5. Response returned

// All these steps will have the same correlation ID