Add service.name/version to OTLP log resource

src/ServiceControl.Infrastructure/LoggerUtil.cs

@@ -2,10 +2,13 @@
 {
     using System;
     using System.Collections.Concurrent;
+    using System.Diagnostics;
+    using System.Reflection;
     using Microsoft.Extensions.DependencyInjection;
     using Microsoft.Extensions.Logging;
     using NLog.Extensions.Logging;
     using OpenTelemetry.Logs;
+    using OpenTelemetry.Resources;
     using ServiceControl.Infrastructure.TestLogger;
 
     [Flags]
@@ -24,11 +27,32 @@ public static class LoggerUtil
 
         public static string SeqAddress { private get; set; }
 
-        public static bool IsLoggingTo(Loggers logger)
+        // Telemetry resource attached to exported OTLP logs (service.name/service.version/service.instance.id).
+        // Set once at process startup via Initialize() — before any logger is created — so both the host pipeline
+        // and the static bootstrap loggers (CreateStaticLogger) share a single instance identity. Defaults to
+        // CreateDefault() (which still honors OTEL_SERVICE_NAME/OTEL_RESOURCE_ATTRIBUTES) for the rare logger
+        // created before Initialize runs.
+        static ResourceBuilder serviceResourceBuilder = CreateResourcesBuilder();
+
+        static ResourceBuilder CreateResourcesBuilder()
         {
-            return (logger & ActiveLoggers) == logger;
+            var asm = Assembly.GetEntryAssembly() ?? throw new InvalidOperationException("Entry assembly not found");
+            var serviceName = asm.GetName().Name ?? throw new InvalidOperationException("Entry assembly name not found");
+            var serviceVersion = FileVersionInfo.GetVersionInfo(asm.Location).ProductVersion;
+
+            // CreateDefault() also reads OTEL_SERVICE_NAME/OTEL_RESOURCE_ATTRIBUTES, so operators can still enrich
+            // the resource with deployment-specific attributes via those environment variables.
+            return ResourceBuilder
+                .CreateDefault()
+                .AddService(
+                    serviceName,
+                    serviceVersion: serviceVersion,
+                    autoGenerateServiceInstanceId: true
+                    );
         }
 
+        public static bool IsLoggingTo(Loggers logger) => (logger & ActiveLoggers) == logger;
+
         public static void ConfigureLogging(this ILoggingBuilder loggingBuilder, LogLevel level)
         {
             loggingBuilder.SetMinimumLevel(level);
@@ -54,7 +78,11 @@ public static void ConfigureLogging(this ILoggingBuilder loggingBuilder, LogLeve
             }
             if (IsLoggingTo(Loggers.Otlp))
             {
-                loggingBuilder.AddOpenTelemetry(configure => configure.AddOtlpExporter());
+                loggingBuilder.AddOpenTelemetry(configure =>
+                {
+                    configure.SetResourceBuilder(serviceResourceBuilder);
+                    configure.AddOtlpExporter();
+                });
             }
         }