Add traceId and spanId properties

Author: tbdrake

Serilog.Sinks.Network.Test/JsonFormatter.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Diagnostics;
 using System.Net;
 using System.Net.Sockets;
 using System.Threading.Tasks;
@@ -11,7 +12,7 @@ namespace Serilog.Sinks.Network.Test
 {
     public class JsonFormatter
     {
-        private static LoggerAndSocket ConfigureTestLogger(ITextFormatter formatter = null)
+        private static LoggerAndSocket ConfigureTestLogger(ITextFormatter? formatter = null)
         {
             var socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
             socket.Bind(new IPEndPoint(IPAddress.Loopback, 0));
@@ -51,5 +52,42 @@ public async Task CanStillLogMessagesWithExceptions()
 
             receivedData.Should().Contain("\"exception\":\"System.Exception: exploding\"}");
         }
+
+        [Fact]
+        public async Task IncludesCurrentActivityTraceAndSpanIds()
+        {
+            // Create an ActivitySource and start an activity.
+            // StartActivity() would return null if there were no listeners.
+            using var activityListener = new ActivityListener
+            {
+                ShouldListenTo = _ => true,
+                Sample = (ref ActivityCreationOptions<ActivityContext> _) => ActivitySamplingResult.AllData,
+            };
+            ActivitySource.AddActivityListener(activityListener);
+            using var activitySource = new ActivitySource("TestSource");
+            using Activity? activity = activitySource.StartActivity();
+
+            using var fixture = ConfigureTestLogger(new LogstashJsonFormatter());
+
+            fixture.Logger.Information("arbitraryMessage");
+
+            var receivedData = await ServerPoller.PollForReceivedData(fixture.Socket);
+
+            receivedData.Should().Contain($"\"traceId\":\"{activity!.TraceId}\"");
+            receivedData.Should().Contain($"\"spanId\":\"{activity.SpanId}\"");
+        }
+
+        [Fact]
+        public async Task OmitsTraceAndSpanIdsWhenThereIsNoActivity()
+        {
+            using var fixture = ConfigureTestLogger(new LogstashJsonFormatter());
+            
+            fixture.Logger.Information("arbitraryMessage");
+
+            var receivedData = await ServerPoller.PollForReceivedData(fixture.Socket);
+
+            receivedData.Should().NotContain("\"traceId\"");
+            receivedData.Should().NotContain("\"spanId\"");
+        }
     }
 }

Serilog.Sinks.Network.Test/Serilog.Sinks.Network.Test.csproj

@@ -3,6 +3,7 @@
   <PropertyGroup>
     <TargetFramework>net6.0</TargetFramework>
     <LangVersion>Preview</LangVersion>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="Serilog.Formatting.Compact" Version="3.0.0" />

Serilog.Sinks.Network.Test/WhenLoggingViaTcp.cs

@@ -15,7 +15,7 @@ namespace Serilog.Sinks.Network.Test
 {
     public class WhenLoggingViaTcp
     {
-        private static LoggerAndSocket ConfigureTestLogger(ITextFormatter formatter = null)
+        private static LoggerAndSocket ConfigureTestLogger(ITextFormatter? formatter = null)
         {
             var socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
             socket.Bind(new IPEndPoint(IPAddress.Loopback, 0));
@@ -66,7 +66,7 @@ public async Task CanLogWithProperties()
             using var fixture = ConfigureTestLogger();
             fixture.Logger.Information("TCP Hello {location}", "world");
             var receivedData = await ServerPoller.PollForReceivedData(fixture.Socket);
-            dynamic payload = JsonConvert.DeserializeObject<ExpandoObject>(receivedData);
+            dynamic? payload = JsonConvert.DeserializeObject<ExpandoObject>(receivedData);
             if (payload == null)
             {
                 throw new AssertionFailedException("expected payload not null");

Serilog.Sinks.Network.Test/WhenLoggingViaUdp.cs

@@ -15,7 +15,7 @@ namespace Serilog.Sinks.Network.Test
 {
     public class WhenLoggingViaUdp 
     {
-        private static LoggerAndSocket ConfigureTestLogger(ITextFormatter formatter = null)
+        private static LoggerAndSocket ConfigureTestLogger(ITextFormatter? formatter = null)
         {
             var socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
             socket.Bind(new IPEndPoint(IPAddress.Loopback, 0));

Serilog.Sinks.Network/Formatters/LogstashJsonFormatter.cs

@@ -47,6 +47,18 @@ private static void FormatContent(LogEvent logEvent, TextWriter output)
 
       WritePropertyAndValue(output, "message", logEvent.MessageTemplate.Render(logEvent.Properties));
 
+      if (logEvent.TraceId != null)
+      {
+        output.Write(",");
+        WritePropertyAndValue(output, "traceId", logEvent.TraceId.Value.ToString());
+      }
+
+      if (logEvent.SpanId != null)
+      {
+        output.Write(",");
+        WritePropertyAndValue(output, "spanId", logEvent.SpanId.Value.ToString());
+      }
+      
       if (logEvent.Exception != null)
       {
         output.Write(",");