[WIP] OpenTelemetry trace id correlation for ILoggingAdapter

src/core/Akka.API.Tests/LogFormatSpec.cs

@@ -8,6 +8,7 @@
 using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.IO;
 using System.Linq;
 using System.Text.RegularExpressions;
@@ -32,9 +33,9 @@ public DefaultLogFormatSpec() : base(CustomLoggerSetup())
     {
         _logger = (CustomLogger)Sys.Settings.StdoutLogger;
     }
-    
+
     private readonly CustomLogger _logger;
-    
+
     public class CustomLogger : StandardOutLogger
     {
         protected override void Log(object message)
@@ -44,13 +45,13 @@ protected override void Log(object message)
             {
                 _events.Add(e);
             }
-           
+
         }
-            
+
         private readonly ConcurrentBag<LogEvent> _events = new();
         public IReadOnlyCollection<LogEvent> Events => _events;
     }
-    
+
     public static ActorSystemSetup CustomLoggerSetup()
     {
         var hocon = @$"
@@ -109,10 +110,51 @@ await AwaitConditionAsync(() =>
         text = SanitizeThreadNumber(text);
         // to resolve https://github.com/akkadotnet/akka.net/issues/7421
         text = SanitizeTestEventListener(text);
-        
+
         await Verifier.Verify(text);
     }
-
+
+    /// <summary>
+    /// Validation spec for https://github.com/akkadotnet/akka.net/issues/6855 
+    /// </summary>
+    [Fact]
+    public async Task ShouldUseDefaultLogFormatWithTraceCorrelation()
+    {
+        // arrange
+        var filePath = Path.GetTempFileName();
+
+        // act
+        using (new OutputRedirector(filePath))
+        {
+            using var activity = new Activity("test").Start();
+            Activity.Current = activity;
+
+            Sys.Log.Debug("This is a test {0} {1}", 1, "cheese");
+            Sys.Log.Info("This is a test {0}", 1);
+            Sys.Log.Warning("This is a test {0}", 1);
+            Sys.Log.Error("This is a test {0}", 1);
+
+            // force all logs to be received
+            await AwaitConditionAsync(() =>
+            {
+                return _logger.Events.Count(c => c.Message.ToString()!.Contains("This is a test")) == 4;
+            });
+        }
+
+        // ReSharper disable once MethodHasAsyncOverload
+        var text = File.ReadAllText(filePath);
+
+        // need to sanitize the thread id
+        text = SanitizeDateTime(text);
+        text = SanitizeThreadNumber(text);
+        // to resolve https://github.com/akkadotnet/akka.net/issues/7421
+        text = SanitizeTestEventListener(text);
+        text = SanitizeTraceId(text);
+
+        await Verifier.Verify(text);
+
+    }
+
     private static string SanitizeTestEventListener(string logs)
     {
         var pattern = @"^.*Akka\.TestKit\.TestEventListener.*$";
@@ -138,4 +180,17 @@ private static string SanitizeDateTime(string logs, string replacement = "DateTi
 
         return result;
     }
-}
+
+     // Matches TraceId=<hex>, SpanId=<hex>
+        private const string PATTERN = 
+            @"TraceId=([0-9a-f]{32}), SpanId=([0-9a-f]{16})";
+
+        private const string REPLACEMENT = 
+            "TraceId=00000000000000000000000000000000, SpanId=0000000000000000";
+
+    private static string SanitizeTraceId(string logs)
+    {
+        var result = Regex.Replace(logs, PATTERN, REPLACEMENT);
+        return result;
+    }
+}

src/core/Akka.API.Tests/verify/CoreAPISpec.ApproveCore.DotNet.verified.txt

@@ -3320,6 +3320,7 @@ namespace Akka.Event
         public Akka.Actor.IActorRef Sender { get; }
         public override string ToString() { }
     }
+    [System.Runtime.CompilerServices.NullableAttribute(0)]
     public sealed class BusLogging : Akka.Event.LoggingAdapterBase
     {
         public BusLogging(Akka.Event.LoggingBus bus, string logSource, System.Type logClass, Akka.Event.ILogMessageFormatter logMessageFormatter) { }
@@ -3349,6 +3350,7 @@ namespace Akka.Event
     {
         public Debug(string logSource, System.Type logClass, object message) { }
         public Debug(System.Exception cause, string logSource, System.Type logClass, object message) { }
+        public Debug(System.Exception cause, string logSource, System.Type logClass, object message, [System.Runtime.CompilerServices.IsReadOnlyAttribute()] ref System.Diagnostics.ActivityContext context) { }
         public override Akka.Event.LogLevel LogLevel() { }
     }
     public class DefaultLogMessageFormatter : Akka.Event.ILogMessageFormatter
@@ -3376,6 +3378,7 @@ namespace Akka.Event
     public class Error : Akka.Event.LogEvent
     {
         public Error(System.Exception cause, string logSource, System.Type logClass, object message) { }
+        public Error(System.Exception cause, string logSource, System.Type logClass, object message, [System.Runtime.CompilerServices.IsReadOnlyAttribute()] ref System.Diagnostics.ActivityContext context) { }
         public override Akka.Event.LogLevel LogLevel() { }
     }
     public abstract class EventBus<TEvent, TClassifier, TSubscriber>
@@ -3434,16 +3437,20 @@ namespace Akka.Event
     {
         public Info(string logSource, System.Type logClass, object message) { }
         public Info(System.Exception cause, string logSource, System.Type logClass, object message) { }
+        public Info(System.Exception cause, string logSource, System.Type logClass, object message, [System.Runtime.CompilerServices.IsReadOnlyAttribute()] ref System.Diagnostics.ActivityContext context) { }
         public override Akka.Event.LogLevel LogLevel() { }
     }
     public class InitializeLogger : Akka.Actor.INoSerializationVerificationNeeded
     {
         public InitializeLogger(Akka.Event.LoggingBus loggingBus) { }
         public Akka.Event.LoggingBus LoggingBus { get; }
     }
+    [System.Runtime.CompilerServices.NullableAttribute(0)]
     public abstract class LogEvent : Akka.Actor.INoSerializationVerificationNeeded
     {
         protected LogEvent() { }
+        public System.Diagnostics.ActivityContext ActivityContext { get; set; }
+        [System.Runtime.CompilerServices.NullableAttribute(2)]
         public System.Exception Cause { get; set; }
         public System.Type LogClass { get; set; }
         public string LogSource { get; set; }
@@ -3723,6 +3730,7 @@ namespace Akka.Event
     {
         public Warning(string logSource, System.Type logClass, object message) { }
         public Warning(System.Exception cause, string logSource, System.Type logClass, object message) { }
+        public Warning(System.Exception cause, string logSource, System.Type logClass, object message, [System.Runtime.CompilerServices.IsReadOnlyAttribute()] ref System.Diagnostics.ActivityContext context) { }
         public override Akka.Event.LogLevel LogLevel() { }
     }
 }

src/core/Akka.API.Tests/verify/CoreAPISpec.ApproveCore.Net.verified.txt

@@ -3312,6 +3312,7 @@ namespace Akka.Event
         public Akka.Actor.IActorRef Sender { get; }
         public override string ToString() { }
     }
+    [System.Runtime.CompilerServices.NullableAttribute(0)]
     public sealed class BusLogging : Akka.Event.LoggingAdapterBase
     {
         public BusLogging(Akka.Event.LoggingBus bus, string logSource, System.Type logClass, Akka.Event.ILogMessageFormatter logMessageFormatter) { }
@@ -3341,6 +3342,7 @@ namespace Akka.Event
     {
         public Debug(string logSource, System.Type logClass, object message) { }
         public Debug(System.Exception cause, string logSource, System.Type logClass, object message) { }
+        public Debug(System.Exception cause, string logSource, System.Type logClass, object message, ref System.Diagnostics.ActivityContext context) { }
         public override Akka.Event.LogLevel LogLevel() { }
     }
     public class DefaultLogMessageFormatter : Akka.Event.ILogMessageFormatter
@@ -3368,6 +3370,7 @@ namespace Akka.Event
     public class Error : Akka.Event.LogEvent
     {
         public Error(System.Exception cause, string logSource, System.Type logClass, object message) { }
+        public Error(System.Exception cause, string logSource, System.Type logClass, object message, ref System.Diagnostics.ActivityContext context) { }
         public override Akka.Event.LogLevel LogLevel() { }
     }
     public abstract class EventBus<TEvent, TClassifier, TSubscriber>
@@ -3426,16 +3429,20 @@ namespace Akka.Event
     {
         public Info(string logSource, System.Type logClass, object message) { }
         public Info(System.Exception cause, string logSource, System.Type logClass, object message) { }
+        public Info(System.Exception cause, string logSource, System.Type logClass, object message, ref System.Diagnostics.ActivityContext context) { }
         public override Akka.Event.LogLevel LogLevel() { }
     }
     public class InitializeLogger : Akka.Actor.INoSerializationVerificationNeeded
     {
         public InitializeLogger(Akka.Event.LoggingBus loggingBus) { }
         public Akka.Event.LoggingBus LoggingBus { get; }
     }
+    [System.Runtime.CompilerServices.NullableAttribute(0)]
     public abstract class LogEvent : Akka.Actor.INoSerializationVerificationNeeded
     {
         protected LogEvent() { }
+        public System.Diagnostics.ActivityContext ActivityContext { get; set; }
+        [System.Runtime.CompilerServices.NullableAttribute(2)]
         public System.Exception Cause { get; set; }
         public System.Type LogClass { get; set; }
         public string LogSource { get; set; }
@@ -3713,6 +3720,7 @@ namespace Akka.Event
     {
         public Warning(string logSource, System.Type logClass, object message) { }
         public Warning(System.Exception cause, string logSource, System.Type logClass, object message) { }
+        public Warning(System.Exception cause, string logSource, System.Type logClass, object message, ref System.Diagnostics.ActivityContext context) { }
         public override Akka.Event.LogLevel LogLevel() { }
     }
 }

src/core/Akka.API.Tests/verify/DefaultLogFormatSpec.ShouldUseDefaultLogFormatWithTraceCorrelation.DotNet.verified.txt

@@ -0,0 +1,4 @@
+[DEBUG][DateTime][Thread 0001][ActorSystem(test)][TraceId=00000000000000000000000000000000, SpanId=0000000000000000, TraceFlags=None] This is a test 1 cheese
+[INFO][DateTime][Thread 0001][ActorSystem(test)][TraceId=00000000000000000000000000000000, SpanId=0000000000000000, TraceFlags=None] This is a test 1
+[WARNING][DateTime][Thread 0001][ActorSystem(test)][TraceId=00000000000000000000000000000000, SpanId=0000000000000000, TraceFlags=None] This is a test 1
+[ERROR][DateTime][Thread 0001][ActorSystem(test)][TraceId=00000000000000000000000000000000, SpanId=0000000000000000, TraceFlags=None] This is a test 1

src/core/Akka/Akka.csproj

@@ -24,6 +24,7 @@
     <PackageReference Include="Polyfill" Version="1.28.0" PrivateAssets="all" />
     <PackageReference Include="System.Reflection.Emit" Version="4.7.0" />
     <PackageReference Include="System.Threading.Channels" Version="$(MicrosoftLibVersion)" />
+    <PackageReference Include="System.Diagnostics.DiagnosticSource" Version="$(MicrosoftLibVersion)" />
   </ItemGroup>
 
   <ItemGroup Label="PublicAnalyzers">

src/core/Akka/Event/BusLogging.cs

@@ -4,7 +4,7 @@
 //     Copyright (C) 2013-2025 .NET Foundation <https://github.com/akkadotnet/akka.net>
 // </copyright>
 //-----------------------------------------------------------------------
-
+#nullable enable
 using System;
 using Akka.Actor;
 
@@ -72,14 +72,16 @@ public BusLogging(LoggingBus bus, string logSource, Type logClass, ILogMessageFo
         /// </summary>
         public override bool IsWarningEnabled { get; }
 
-        private LogEvent CreateLogEvent(LogLevel logLevel, object message, Exception cause = null)
+        private LogEvent CreateLogEvent(LogLevel logLevel, object message, Exception? cause = null)
         {
+            var currentContext = (System.Diagnostics.Activity.Current?.Context ?? default);
+
             return logLevel switch
             {
-                LogLevel.DebugLevel => new Debug(cause, LogSource, LogClass, message),
-                LogLevel.InfoLevel => new Info(cause, LogSource, LogClass, message),
-                LogLevel.WarningLevel => new Warning(cause, LogSource, LogClass, message),
-                LogLevel.ErrorLevel => new Error(cause, LogSource, LogClass, message),
+                LogLevel.DebugLevel => new Debug(cause, LogSource, LogClass, message, currentContext),
+                LogLevel.InfoLevel => new Info(cause, LogSource, LogClass, message, currentContext),
+                LogLevel.WarningLevel => new Warning(cause, LogSource, LogClass, message, currentContext),
+                LogLevel.ErrorLevel => new Error(cause, LogSource, LogClass, message, currentContext),
                 _ => throw new ArgumentOutOfRangeException(nameof(logLevel), logLevel, null)
             };
         }

src/core/Akka/Event/Debug.cs

@@ -6,6 +6,7 @@
 //-----------------------------------------------------------------------
 
 using System;
+using System.Diagnostics;
 
 namespace Akka.Event
 {
@@ -32,12 +33,26 @@ public Debug(string logSource, Type logClass, object message)
         /// <param name="logSource">The source that generated the log event.</param>
         /// <param name="logClass">The type of logger used to log the event.</param>
         /// <param name="message">The message that is being logged.</param>
-        public Debug(Exception cause, string logSource, Type logClass, object message)
+        public Debug(Exception cause, string logSource, Type logClass, object message) 
+            : this(cause, logSource, logClass, message, default)
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Debug" /> class.
+        /// </summary>
+        /// <param name="cause">The exception that generated the log event.</param>
+        /// <param name="logSource">The source that generated the log event.</param>
+        /// <param name="logClass">The type of logger used to log the event.</param>
+        /// <param name="message">The message that is being logged.</param>
+        /// <param name="context">The current <see cref="Activity"/>'s context, if one is present.</param>>
+        public Debug(Exception cause, string logSource, Type logClass, object message, in ActivityContext context)
         {
             LogSource = logSource;
             LogClass = logClass;
             Message = message;
             Cause = cause;
+            ActivityContext = context;
         }
 
         /// <summary>

src/core/Akka/Event/Error.cs

@@ -6,6 +6,7 @@
 //-----------------------------------------------------------------------
 
 using System;
+using System.Diagnostics;
 
 namespace Akka.Event
 {
@@ -22,11 +23,25 @@ public class Error : LogEvent
         /// <param name="logClass">The type of logger used to log the event.</param>
         /// <param name="message">The message that is being logged.</param>
         public Error(Exception cause, string logSource, Type logClass, object message)
+            : this(cause, logSource, logClass, message, default)
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Error" /> class.
+        /// </summary>
+        /// <param name="cause">The exception that caused the log event.</param>
+        /// <param name="logSource">The source that generated the log event.</param>
+        /// <param name="logClass">The type of logger used to log the event.</param>
+        /// <param name="message">The message that is being logged.</param>
+        /// <param name="context">The current <see cref="Activity"/>'s context, if one is present.</param>
+        public Error(Exception cause, string logSource, Type logClass, object message, in ActivityContext context)
         {
             Cause = cause;
             LogSource = logSource;
             LogClass = logClass;
             Message = message;
+            ActivityContext = context;
         }
 
         /// <summary>

src/core/Akka/Event/Info.cs

@@ -6,6 +6,7 @@
 //-----------------------------------------------------------------------
 
 using System;
+using System.Diagnostics;
 
 namespace Akka.Event
 {
@@ -32,12 +33,27 @@ public Info(string logSource, Type logClass, object message)
         /// <param name="logSource">The source that generated the log event.</param>
         /// <param name="logClass">The type of logger used to log the event.</param>
         /// <param name="message">The message that is being logged.</param>
-        public Info(Exception cause, string logSource, Type logClass, object message)
+        public Info(Exception cause, string logSource, Type logClass, object message) 
+            : this(cause, logSource, logClass, message, default)
+        {
+
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Info" /> class.
+        /// </summary>
+        /// <param name="cause">The exception that generated the log event.</param>
+        /// <param name="logSource">The source that generated the log event.</param>
+        /// <param name="logClass">The type of logger used to log the event.</param>
+        /// <param name="message">The message that is being logged.</param>
+        /// <param name="context">The current <see cref="Activity"/>'s context, if one is present.</param>
+        public Info(Exception cause, string logSource, Type logClass, object message, in ActivityContext context)
         {
             Cause = cause;
             LogSource = logSource;
             LogClass = logClass;
             Message = message;
+            ActivityContext = context;
         }
 
         /// <summary>