Simplified the Asp.NET Core OpenTelemetry sample (#3142)

Author: jamescrosswell

samples/Sentry.Samples.OpenTelemetry.AspNetCore/Program.cs

@@ -11,6 +11,20 @@
 // OpenTelemetry Configuration
 // See https://opentelemetry.io/docs/instrumentation/net/getting-started/
 builder.Services.AddOpenTelemetry()
+    // This block configures OpenTelemetry to send traces to Sentry
+    .WithTracing(tracerProviderBuilder =>
+        tracerProviderBuilder
+            // Here we add a custom source we've created, which sends telemetry in the `LookupUser` method below
+            .AddSampleInstrumentation()
+            // Here we can optionally configure resource attributes that get sent with every trace
+            .ConfigureResource(resource => resource.AddService(SampleTelemetry.ServiceName))
+            // The two lines below take care of configuring sources for ASP.NET Core and HttpClient
+            .AddAspNetCoreInstrumentation()
+            .AddHttpClientInstrumentation()
+            // Finally we configure OpenTelemetry to send traces to Sentry
+            .AddSentry()
+    )
+    // This block configures OpenTelemetry metrics that we care about... later we'll configure Sentry to capture these
     .WithMetrics(metrics =>
     {
         metrics
@@ -20,28 +34,26 @@
                 "Microsoft.AspNetCore.Hosting",
                 "Microsoft.AspNetCore.Server.Kestrel",
                 "System.Net.Http");
-    })
-    .WithTracing(tracerProviderBuilder =>
-        tracerProviderBuilder
-            .AddSource(Telemetry.ActivitySource.Name)
-            .ConfigureResource(resource => resource.AddService(Telemetry.ServiceName))
-            .AddAspNetCoreInstrumentation()
-            .AddHttpClientInstrumentation()
-            .AddSentry() // <-- Configure OpenTelemetry to send traces to Sentry
-    );
+    });
 
 builder.WebHost.UseSentry(options =>
 {
     // options.Dsn = "...Your DSN...";
     options.Debug = builder.Environment.IsDevelopment();
     options.SendDefaultPii = true;
     options.TracesSampleRate = 1.0;
+    options.UseOpenTelemetry(); // <-- Configure Sentry to use OpenTelemetry trace information
     // This shows experimental support for capturing OpenTelemetry metrics with Sentry
     options.ExperimentalMetrics = new ExperimentalMetricsOptions()
     {
+        // Here we're telling Sentry to capture all built-in metrics. This includes all the metrics we configured
+        // OpenTelemetry to emit when we called `builder.Services.AddOpenTelemetry()` above:
+        // - "OpenTelemetry.Instrumentation.Runtime"
+        // - "Microsoft.AspNetCore.Hosting",
+        // - "Microsoft.AspNetCore.Server.Kestrel",
+        // - "System.Net.Http"
         CaptureSystemDiagnosticsMeters = BuiltInSystemDiagnosticsMeters.All
     };
-    options.UseOpenTelemetry(); // <-- Configure Sentry to use OpenTelemetry trace information
 });
 
 builder.Services
@@ -85,7 +97,7 @@
 
 static string LookupUser(HttpRequest request)
 {
-    using var _ = Telemetry.ActivitySource.StartActivity(nameof(LookupUser));
+    using var _ = SampleTelemetry.ActivitySource.StartActivity(nameof(LookupUser));
     Thread.Sleep(100); // Simulate some work
     return (request.Query.TryGetValue("name", out var name))
         ? name.ToString()

samples/Sentry.Samples.OpenTelemetry.AspNetCore/Telemetry.cs renamed to samples/Sentry.Samples.OpenTelemetry.AspNetCore/SampleTelemetry.cs

@@ -1,9 +1,12 @@
 using System.Diagnostics;
+using OpenTelemetry.Trace;
 
 namespace Sentry.Samples.OpenTelemetry.AspNetCore;
 
-public static class Telemetry
+public static class SampleTelemetry
 {
     public const string ServiceName = "Sentry.Samples.OpenTelemetry.AspNetCore";
     public static ActivitySource ActivitySource { get; } = new(ServiceName);
+    public static TracerProviderBuilder AddSampleInstrumentation(this TracerProviderBuilder builder)
+        => builder.AddSource(ServiceName);
 }