dotnet add package Core.Observability

3-Line OpenTelemetry ASP.NET Core Integration

• trace id in response header
• sends logs, metrics and traces to opentelemetry collector
• enrichment/augmentation of logs and traces even when exceptions occur
• exceptions recorded on traces, client disconnects ignored
• inject trace id to http requests
• health checks (excluded from tracing)
• best practices from aspire
  • servicediscovery
  • http resilience handler

Initialization in ASP.NET Core

builder.AddObservability();

builder.Services.Configure<ObservabilityOptions>(options =>
{
    options.TraceIdHeader = "x-trace-id";
    options.Augment = (context, tags) =>
    {
        tags.Add("TenantId", "extract from http context");
        return ValueTask.CompletedTask;
    };
});

// required - register early, so exceptions from later middleware are enriched and handled
app.UseObservability();

// optional - /health and /alive are anonymous, consider mapping them only in development or on an internal port
app.MapObservabilityHealthChecks();

app.UseAuthorization();

app.MapControllers();
app.Run();

More Instrumentation

builder.AddObservability(configureTracing: tracer =>
{
    tracer.AddEntityFrameworkCoreInstrumentation();
    tracer.AddRedisInstrumentation();
});

Environment Variables

"OTEL_SERVICE_NAME": "my-project",
"OTEL_RESOURCE_ATTRIBUTES": "service.namespace=core,environment.name=dev",

"OTEL_EXPORTER_OTLP_ENDPOINT": "http://localhost:4317",
or
"OTEL_EXPORTER_OTLP_ENDPOINT": "http://collector:4317",

"OTEL_EXPORTER_OTLP_PROTOCOL": "grpc"