Report OTLP export status in tracer startup log

tracer/src/Datadog.Trace/Agent/TracesEncodingExtensions.cs

@@ -0,0 +1,22 @@
+// <copyright file="TracesEncodingExtensions.cs" company="Datadog">
+// Unless explicitly stated otherwise all files in this repository are licensed under the Apache 2 License.
+// This product includes software developed at Datadog (https://www.datadoghq.com/). Copyright 2017 Datadog, Inc.
+// </copyright>
+
+#nullable enable
+
+namespace Datadog.Trace.Agent;
+
+internal static class TracesEncodingExtensions
+{
+    /// <summary>
+    /// Returns <c>true</c> when traces are exported using any OTLP encoding.
+    /// </summary>
+    /// <remarks>
+    /// Defined as "not a Datadog-native encoding" so future OTLP encodings (e.g. gRPC) are covered
+    /// automatically; if a new Datadog-native encoding is added, exclude it here. The unsupported-OTLP-protocol
+    /// fallback resolves to <see cref="TracesEncoding.DatadogV0_4"/>, so this correctly returns <c>false</c> for it.
+    /// </remarks>
+    public static bool IsOtlp(this TracesEncoding encoding)
+        => encoding is not TracesEncoding.DatadogV0_4;
+}

tracer/src/Datadog.Trace/TracerManager.cs

@@ -555,6 +555,15 @@ void WriteDictionary(IReadOnlyDictionary<string, string> dictionary)
                     writer.WritePropertyName("activity_listener_enabled");
                     writer.WriteValue(instanceSettings.IsActivityListenerEnabled);
 
+                    writer.WritePropertyName("otlp_traces_export_enabled");
+                    writer.WriteValue(exporterSettings.TracesEncoding.IsOtlp());
+
+                    writer.WritePropertyName("otlp_metrics_export_enabled");
+                    writer.WriteValue(instanceSettings.OtlpRuntimeMetricsEnabled);
+
+                    writer.WritePropertyName("otlp_logs_export_enabled");
+                    writer.WriteValue(instanceSettings.OpenTelemetryLogsEnabled && instanceSettings.OtelLogsExporterEnabled);
+
                     writer.WritePropertyName("profiler_enabled");
                     writer.WriteValue(Profiler.Instance.Status.IsProfilerReady);
 

tracer/src/Datadog.Trace/TracerManagerFactory.cs

@@ -285,7 +285,7 @@ protected virtual ISpanSampler GetSpanSampler(TracerSettings settings)
 
         protected virtual IAgentWriter GetAgentWriter(TracerSettings settings, IStatsdManager statsd, Action<Dictionary<string, float>> updateSampleRates, Action<string> updateConfigHash, IDiscoveryService discoveryService, TelemetrySettings telemetrySettings)
         {
-            if (settings.Manager.InitialExporterSettings.TracesEncoding is TracesEncoding.OtlpProtobuf or TracesEncoding.OtlpJson)
+            if (settings.Manager.InitialExporterSettings.TracesEncoding.IsOtlp())
             {
                 var otlpApi = new ManagedApiOtlp(settings);
                 var otlpStatsAggregator = StatsAggregator.Create(otlpApi, settings, discoveryService, statsd, isOtlp: true);