Sync Serilog scope properties to Sentry events (#3976)

Author: jamescrosswell

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 ### Features
 
+- Serilog scope properties are now sent with Sentry events ([#3976](https://github.com/getsentry/sentry-dotnet/pull/3976))
 - The sample seed used for sampling decisions is now propagated, for use in downstream custom trace samplers ([#3951](https://github.com/getsentry/sentry-dotnet/pull/3951))
 
 ### Fixes

src/Sentry.Serilog/SentryOptionExtensions.cs

@@ -0,0 +1,21 @@
+namespace Sentry.Serilog;
+
+/// <summary>
+/// Extensions for <see cref="SentryOptions"/> to add Serilog specific configuration.
+/// </summary>
+public static class SentryOptionExtensions
+{
+    /// <summary>
+    /// Ensures Serilog scope properties get applied to Sentry events. If you are not initialising Sentry when
+    /// configuring the Sentry sink for Serilog then you should call this method in the options callback for whichever
+    /// Sentry integration you are using to initialise Sentry.
+    /// </summary>
+    /// <param name="options"></param>
+    /// <typeparam name="T"></typeparam>
+    /// <returns></returns>
+    public static T ApplySerilogScopeToEvents<T>(this T options) where T : SentryOptions
+    {
+        options.AddEventProcessor(new SerilogScopeEventProcessor(options));
+        return options;
+    }
+}

src/Sentry.Serilog/SentrySinkExtensions.cs

@@ -326,6 +326,14 @@ internal static void ConfigureSentrySerilogOptions(
                 sentrySerilogOptions.DefaultTags.Add(tag.Key, tag.Value);
             }
         }
+
+        // This only works when the SDK is initialized using the LoggerSinkConfiguration extensions. If the SDK is
+        // initialized using some other integration then the processor will need to be added manually to whichever
+        // options are used to initialize the SDK.
+        if (sentrySerilogOptions.InitializeSdk)
+        {
+            sentrySerilogOptions.ApplySerilogScopeToEvents();
+        }
     }
 
     /// <summary>

src/Sentry.Serilog/SerilogScopeEventProcessor.cs

@@ -0,0 +1,57 @@
+using Serilog.Context;
+
+namespace Sentry.Serilog;
+
+/// <summary>
+/// Sentry event processor that applies properties from the Serilog scope to Sentry events.
+/// </summary>
+internal class SerilogScopeEventProcessor : ISentryEventProcessor
+{
+    private readonly SentryOptions _options;
+
+    /// <summary>
+    /// This processor extracts properties from the Serilog context and applies these to Sentry events.
+    /// </summary>
+    public SerilogScopeEventProcessor(SentryOptions options)
+    {
+        _options = options;
+        _options.LogDebug("Initializing Serilog scope event processor.");
+    }
+
+    /// <inheritdoc cref="ISentryEventProcessor"/>
+    public SentryEvent Process(SentryEvent @event)
+    {
+        _options.LogDebug("Running Serilog scope event processor on: Event {0}", @event.EventId);
+
+        // This is a bit of a hack. Serilog doesn't have any hooks that let us inspect the context. We can, however,
+        // apply the context to a dummy log event and then copy across the properties from that log event to our Sentry
+        // event.
+        // See: https://github.com/getsentry/sentry-dotnet/issues/3544#issuecomment-2307884977
+        var enricher = LogContext.Clone();
+        var logEvent = new LogEvent(DateTimeOffset.Now, LogEventLevel.Error, null, MessageTemplate.Empty, []);
+        enricher.Enrich(logEvent, new LogEventPropertyFactory());
+        foreach (var (key, value) in logEvent.Properties)
+        {
+            if (!@event.Tags.ContainsKey(key))
+            {
+                // Potentially we could be doing SetData here instead of SetTag. See DefaultSentryScopeStateProcessor.
+                @event.SetTag(
+                    key,
+                    value is ScalarValue { Value: string stringValue }
+                        ? stringValue
+                        : value.ToString()
+                    );
+            }
+        }
+        return @event;
+    }
+
+    private class LogEventPropertyFactory : ILogEventPropertyFactory
+    {
+        public LogEventProperty CreateProperty(string name, object? value, bool destructureObjects = false)
+        {
+            var scalarValue = new ScalarValue(value);
+            return new LogEventProperty(name, scalarValue);
+        }
+    }
+}

test/Sentry.Serilog.Tests/ApiApprovalTests.Run.DotNet8_0.verified.txt

@@ -1,6 +1,11 @@
 [assembly: System.CLSCompliant(true)]
 namespace Sentry.Serilog
 {
+    public static class SentryOptionExtensions
+    {
+        public static T ApplySerilogScopeToEvents<T>(this T options)
+            where T : Sentry.SentryOptions { }
+    }
     public class SentrySerilogOptions : Sentry.SentryOptions
     {
         public SentrySerilogOptions() { }

test/Sentry.Serilog.Tests/ApiApprovalTests.Run.DotNet9_0.verified.txt

@@ -1,6 +1,11 @@
 [assembly: System.CLSCompliant(true)]
 namespace Sentry.Serilog
 {
+    public static class SentryOptionExtensions
+    {
+        public static T ApplySerilogScopeToEvents<T>(this T options)
+            where T : Sentry.SentryOptions { }
+    }
     public class SentrySerilogOptions : Sentry.SentryOptions
     {
         public SentrySerilogOptions() { }

test/Sentry.Serilog.Tests/ApiApprovalTests.Run.Net4_8.verified.txt

@@ -1,6 +1,11 @@
 [assembly: System.CLSCompliant(true)]
 namespace Sentry.Serilog
 {
+    public static class SentryOptionExtensions
+    {
+        public static T ApplySerilogScopeToEvents<T>(this T options)
+            where T : Sentry.SentryOptions { }
+    }
     public class SentrySerilogOptions : Sentry.SentryOptions
     {
         public SentrySerilogOptions() { }

test/Sentry.Serilog.Tests/SerilogScopeEventProcessorTests.cs

@@ -0,0 +1,32 @@
+using Microsoft.Extensions.Logging;
+
+namespace Sentry.Serilog.Tests;
+
+public class SerilogScopeEventProcessorTests
+{
+    [Theory]
+    [InlineData("42", "42")]
+    [InlineData(42, "42")]
+    public void Emit_WithException_CreatesEventWithException(object value, string expected)
+    {
+        // Arrange
+        var options = new SentryOptions();
+        var sut = new SerilogScopeEventProcessor(options);
+
+        using var log = new LoggerConfiguration().CreateLogger();
+        var factory = new LoggerFactory().AddSerilog(log);
+        var logger = factory.CreateLogger<SerilogScopeEventProcessorTests>();
+
+        // Act
+        SentryEvent evt;
+        using (logger.BeginScope(new Dictionary<string, object> { ["Answer"] = value }))
+        {
+            evt = new SentryEvent();
+            sut.Process(evt);
+        }
+
+        // Assert
+        evt.Tags.Should().ContainKey("Answer");
+        evt.Tags["Answer"].Should().Be(expected);
+    }
+}