Add service.name/version to OTLP log resource

src/ServiceControl.Audit/HostApplicationBuilderExtensions.cs

@@ -39,7 +39,7 @@ public static void AddServiceControlAudit(this IHostApplicationBuilder builder,
         RecordStartup(settings, configuration, persistenceConfiguration);
 
         builder.Logging.ClearProviders();
-        builder.Logging.ConfigureLogging(settings.LoggingSettings.LogLevel);
+        builder.Logging.ConfigureLogging(settings.LoggingSettings.LogLevel, settings.InstanceName, InstanceVersion);
 
         var services = builder.Services;
         var transportSettings = settings.ToTransportSettings();

src/ServiceControl.Infrastructure/LoggerUtil.cs

@@ -6,6 +6,7 @@
     using Microsoft.Extensions.Logging;
     using NLog.Extensions.Logging;
     using OpenTelemetry.Logs;
+    using OpenTelemetry.Resources;
     using ServiceControl.Infrastructure.TestLogger;
 
     [Flags]
@@ -29,7 +30,24 @@ public static bool IsLoggingTo(Loggers logger)
             return (logger & ActiveLoggers) == logger;
         }
 
-        public static void ConfigureLogging(this ILoggingBuilder loggingBuilder, LogLevel level)
+        // Configures the host logging pipeline. serviceName/serviceVersion identify this instance and are
+        // attached to exported OTLP telemetry as resource attributes (service.name/service.version) so logs
+        // are attributable instead of arriving as "unknown_service". They are mandatory: the host always knows
+        // its instance name and version, and the alternative (defaulting them) is what produced unattributable logs.
+        public static void ConfigureLogging(this ILoggingBuilder loggingBuilder, LogLevel level, string serviceName, string serviceVersion)
+        {
+            ArgumentException.ThrowIfNullOrEmpty(serviceName);
+            ArgumentException.ThrowIfNullOrEmpty(serviceVersion);
+
+            // CreateDefault() also reads OTEL_SERVICE_NAME/OTEL_RESOURCE_ATTRIBUTES, so operators can still enrich
+            // the resource with deployment-specific attributes via those environment variables.
+            var resourceBuilder = ResourceBuilder.CreateDefault()
+                .AddService(serviceName, serviceVersion: serviceVersion, autoGenerateServiceInstanceId: true);
+
+            loggingBuilder.AddProviders(level, resourceBuilder);
+        }
+
+        static void AddProviders(this ILoggingBuilder loggingBuilder, LogLevel level, ResourceBuilder resourceBuilder)
         {
             loggingBuilder.SetMinimumLevel(level);
 
@@ -54,7 +72,11 @@ public static void ConfigureLogging(this ILoggingBuilder loggingBuilder, LogLeve
             }
             if (IsLoggingTo(Loggers.Otlp))
             {
-                loggingBuilder.AddOpenTelemetry(configure => configure.AddOtlpExporter());
+                loggingBuilder.AddOpenTelemetry(configure =>
+                {
+                    configure.SetResourceBuilder(resourceBuilder);
+                    configure.AddOtlpExporter();
+                });
             }
         }
 
@@ -64,7 +86,10 @@ static ILoggerFactory GetOrCreateLoggerFactory(LogLevel level)
         {
             if (!_factories.TryGetValue(level, out var factory))
             {
-                factory = LoggerFactory.Create(configure => configure.ConfigureLogging(level));
+                // Static/bootstrap loggers are created from scattered call sites that have no instance identity
+                // (and many run before it is known). They use the default resource, which still honors
+                // OTEL_SERVICE_NAME/OTEL_RESOURCE_ATTRIBUTES if the operator sets them.
+                factory = LoggerFactory.Create(configure => configure.AddProviders(level, ResourceBuilder.CreateDefault()));
                 _factories[level] = factory;
             }
 

src/ServiceControl.Monitoring.AcceptanceTests/TestSupport/ServiceControlComponentRunner.cs

@@ -98,7 +98,7 @@ async Task InitializeServiceControl(ScenarioContext context)
                     EnvironmentName = Environments.Development
                 });
                 hostBuilder.Logging.ClearProviders();
-                hostBuilder.Logging.ConfigureLogging(LogLevel.Information);
+                hostBuilder.Logging.ConfigureLogging(LogLevel.Information, settings.InstanceName, "0.0.0");
                 hostBuilder.Logging.AddContextAppender(context);
 
                 hostBuilder.Services.AddScenarioContext(context);

src/ServiceControl.Monitoring/HostApplicationBuilderExtensions.cs

@@ -1,6 +1,7 @@
 namespace ServiceControl.Monitoring;
 
 using System;
+using System.Diagnostics;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
@@ -26,11 +27,13 @@ namespace ServiceControl.Monitoring;
 
 public static class HostApplicationBuilderExtensions
 {
+    static readonly string InstanceVersion = FileVersionInfo.GetVersionInfo(typeof(HostApplicationBuilderExtensions).Assembly.Location).ProductVersion;
+
     public static void AddServiceControlMonitoring(this IHostApplicationBuilder hostBuilder,
         Func<ICriticalErrorContext, CancellationToken, Task> onCriticalError, Settings settings,
         EndpointConfiguration endpointConfiguration)
     {
-        hostBuilder.Logging.ConfigureLogging(settings.LoggingSettings.LogLevel);
+        hostBuilder.Logging.ConfigureLogging(settings.LoggingSettings.LogLevel, settings.InstanceName, InstanceVersion);
 
         var services = hostBuilder.Services;
 

src/ServiceControl.Persistence.Tests/PersistenceTestBase.cs

@@ -34,7 +34,7 @@ public async Task SetUp()
         var hostBuilder = Host.CreateApplicationBuilder();
 
         LoggerUtil.ActiveLoggers = Loggers.Test;
-        hostBuilder.Logging.ConfigureLogging(LogLevel.Information);
+        hostBuilder.Logging.ConfigureLogging(LogLevel.Information, "ServiceControl.Persistence.Tests", "0.0.0");
 
         await PersistenceTestsContext.Setup(hostBuilder);
 

src/ServiceControl/HostApplicationBuilderExtensions.cs

@@ -30,6 +30,8 @@ namespace Particular.ServiceControl
 
     static class HostApplicationBuilderExtensions
     {
+        static readonly string InstanceVersion = FileVersionInfo.GetVersionInfo(typeof(HostApplicationBuilderExtensions).Assembly.Location).ProductVersion;
+
         public static void AddServiceControl(this IHostApplicationBuilder hostBuilder, Settings settings, EndpointConfiguration configuration, params ReadOnlySpan<ServiceControlComponent> components)
         {
             ArgumentNullException.ThrowIfNull(configuration);
@@ -42,7 +44,7 @@ public static void AddServiceControl(this IHostApplicationBuilder hostBuilder, S
             }
 
             hostBuilder.Logging.ClearProviders();
-            hostBuilder.Logging.ConfigureLogging(settings.LoggingSettings.LogLevel);
+            hostBuilder.Logging.ConfigureLogging(settings.LoggingSettings.LogLevel, settings.InstanceName, InstanceVersion);
 
             var componentSetupContext = new ComponentInstallationContext();
             var serviceControlComponents = components is { Length: 0 } ? ServiceControlMainInstance.Components : components;
@@ -112,11 +114,9 @@ public static void AddServiceControlInstallers(this IHostApplicationBuilder host
 
         static void RecordStartup(Settings settings, EndpointConfiguration endpointConfiguration)
         {
-            var version = FileVersionInfo.GetVersionInfo(typeof(HostApplicationBuilderExtensions).Assembly.Location).ProductVersion;
-
             var startupMessage = $@"
 -------------------------------------------------------------
-ServiceControl Version:             {version}
+ServiceControl Version:             {InstanceVersion}
 Audit Retention Period (optional):  {settings.AuditRetentionPeriod}
 Error Retention Period:             {settings.ErrorRetentionPeriod}
 Ingest Error Messages:              {settings.IngestErrorMessages}