Use new UseOtlpExporter method from the OTEL library

[davidfowl]

open-telemetry/opentelemetry-dotnet#5400

[DamianEdwards]

Currently available in 1.8.0-beta.1

This would be an update to the templates IIUC, specifically the ServiceDefaults project. We should wait until there's a stable release before integrating I think.

[CodeBlanch]

Really the whole point of putting out that beta was for Aspire to take it for a spin and provide feedback 🤣 Please do!

Here's the things in 1.8.0-beta.1 which should be of interest to Aspire:

• Addition of UseOtlpExporter
• Removal of OTEL_DOTNET_EXPERIMENTAL_OTLP_EMIT_EXCEPTION_LOG_ATTRIBUTES
• Addition of OTEL_DOTNET_EXPERIMENTAL_OTLP_ENABLE_INMEMORY_RETRY

This one didn't make the first beta but will come in the next drop: open-telemetry/opentelemetry-dotnet#5448

[DamianEdwards]

@CodeBlanch great! I'll try it out to get a sense of how it would impact our experience, thanks.

[DamianEdwards]

OK so yeah, this allows us to simplify the ServiceDefaults code to enable OTLP quite a bit:

private static IHostApplicationBuilder AddOpenTelemetryExporters(this IHostApplicationBuilder builder)
{
+    builder.Services.AddOpenTelemetry()
+       // Enable OTLP exporter for all telemetry based on defaults and environment variables
+       .UseOtlpExporter();
+       // Uncomment the following lines to enable the Prometheus exporter (requires the OpenTelemetry.Exporter.Prometheus.AspNetCore package)
+       //.WithMetrics(metrics => metrics.AddPrometheusExporter());
    
-    var useOtlpExporter = !string.IsNullOrWhiteSpace(builder.Configuration["OTEL_EXPORTER_OTLP_ENDPOINT"]);
    
-    if (useOtlpExporter)
-    {
-        builder.Services.Configure<OpenTelemetryLoggerOptions>(logging => logging.AddOtlpExporter());
-        builder.Services.ConfigureOpenTelemetryMeterProvider(metrics => metrics.AddOtlpExporter());
-        builder.Services.ConfigureOpenTelemetryTracerProvider(tracing => tracing.AddOtlpExporter());
-    }

-    // Uncomment the following lines to enable the Prometheus exporter (requires the OpenTelemetry.Exporter.Prometheus.AspNetCore package)
-    // builder.Services.AddOpenTelemetry()
-    //    .WithMetrics(metrics => metrics.AddPrometheusExporter());
    
    // Uncomment the following lines to enable the Azure Monitor exporter (requires the Azure.Monitor.OpenTelemetry.AspNetCore package)
    //if (!string.IsNullOrEmpty(builder.Configuration["APPLICATIONINSIGHTS_CONNECTION_STRING"]))
    //{
    //    builder.Services.AddOpenTelemetry()
    //       .UseAzureMonitor();
    //}

     return builder;
}

[DamianEdwards]

I'll move this to preview.6 as I'm not expecting we're going to get a stable version of the package with this change in time for preview.5