Add process tags to dynamic instrumentation snapshots (#7839)

## Summary of changes

add a process tags field next to where the service name is added in the
snapshot json.

dotnet version of DataDog/dd-trace-java#8779

## Reason for change

AIDM-195

## Implementation details

I wanted to inject the setting from
https://github.com/DataDog/dd-trace-dotnet/blob/79b266b0c7a329eae91584356a1cfc7c5599c1ee/tracer/src/Datadog.Trace/Debugger/DebuggerFactory.cs#L30
but looking at the call chain to bring it to the snapshot creator, it
was quite tedious and messy.
Another option was to put it in the debugger settings, but it felt out
of place as those settings are specific to the live debugger, not a
repeat of global tracer settings.
In the end I decided to inject _a little bit_ so that I could specify
the value in tests.

## Test coverage

just made sure the test that checks json correctness includes this

## Other details
<!-- Fixes #{issue} -->


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Author: vandonr

tracer/src/Datadog.Trace/Debugger/ExceptionAutoInstrumentation/ExceptionReplaySnapshotCreator.cs

@@ -14,13 +14,13 @@ namespace Datadog.Trace.Debugger.ExceptionAutoInstrumentation
 {
     internal class ExceptionReplaySnapshotCreator : DebuggerSnapshotCreator
     {
-        public ExceptionReplaySnapshotCreator(bool isFullSnapshot, ProbeLocation location, bool hasCondition, string[] tags, CaptureLimitInfo limitInfo)
-            : base(isFullSnapshot, location, hasCondition, tags, limitInfo)
+        public ExceptionReplaySnapshotCreator(bool isFullSnapshot, ProbeLocation location, bool hasCondition, string[] tags, CaptureLimitInfo limitInfo, bool withProcessTags)
+            : base(isFullSnapshot, location, hasCondition, tags, limitInfo, withProcessTags)
         {
         }
 
-        public ExceptionReplaySnapshotCreator(bool isFullSnapshot, ProbeLocation location, bool hasCondition, string[] tags, MethodScopeMembers methodScopeMembers, CaptureLimitInfo limitInfo)
-            : base(isFullSnapshot, location, hasCondition, tags, methodScopeMembers, limitInfo)
+        public ExceptionReplaySnapshotCreator(bool isFullSnapshot, ProbeLocation location, bool hasCondition, string[] tags, MethodScopeMembers methodScopeMembers, CaptureLimitInfo limitInfo, bool withProcessTags)
+            : base(isFullSnapshot, location, hasCondition, tags, methodScopeMembers, limitInfo, withProcessTags)
         {
         }
 

tracer/src/Datadog.Trace/Debugger/ExceptionAutoInstrumentation/TrackedStackFrameNode.cs

@@ -134,7 +134,7 @@ private string CreateSnapshot()
                 MaxFieldCount: DebuggerSettings.DefaultMaxNumberOfFieldsToCopy,
                 MaxLength: DebuggerSettings.DefaultMaxStringLength);
 
-            using var snapshotCreator = new ExceptionReplaySnapshotCreator(isFullSnapshot: true, location: ProbeLocation.Method, hasCondition: false, Array.Empty<string>(), members, limitInfo: limitInfo);
+            using var snapshotCreator = new ExceptionReplaySnapshotCreator(isFullSnapshot: true, ProbeLocation.Method, hasCondition: false, [], members, limitInfo, Tracer.Instance.Settings.PropagateProcessTags);
 
             _snapshotId = snapshotCreator.SnapshotId;
 

tracer/src/Datadog.Trace/Debugger/Expressions/ProbeProcessor.cs

@@ -121,7 +121,7 @@ public IProbeProcessor UpdateProbeProcessor(ProbeDefinition probe)
 
         public IDebuggerSnapshotCreator CreateSnapshotCreator()
         {
-            return new DebuggerSnapshotCreator(ProbeInfo.IsFullSnapshot, ProbeInfo.ProbeLocation, ProbeInfo.HasCondition, ProbeInfo.Tags, ProbeInfo.CaptureLimitInfo);
+            return new DebuggerSnapshotCreator(ProbeInfo.IsFullSnapshot, ProbeInfo.ProbeLocation, ProbeInfo.HasCondition, ProbeInfo.Tags, ProbeInfo.CaptureLimitInfo, Tracer.Instance.Settings.PropagateProcessTags);
         }
 
         private void SetExpressions(ProbeDefinition probe)

tracer/src/Datadog.Trace/Debugger/Snapshots/DebuggerSnapshotCreator.cs

@@ -33,6 +33,7 @@ internal class DebuggerSnapshotCreator : IDebuggerSnapshotCreator, IDisposable
         private readonly bool _isFullSnapshot;
         private readonly ProbeLocation _probeLocation;
         private readonly CaptureLimitInfo _limitInfo;
+        private readonly bool _injectProcessTags;
 
         private long _lastSampledTime;
         private TimeSpan _accumulatedDuration;
@@ -42,7 +43,7 @@ internal class DebuggerSnapshotCreator : IDebuggerSnapshotCreator, IDisposable
         private string _snapshotId;
         private ObjectPool<MethodScopeMembers, MethodScopeMembersParameters> _scopeMembersPool;
 
-        public DebuggerSnapshotCreator(bool isFullSnapshot, ProbeLocation location, bool hasCondition, string[] tags, CaptureLimitInfo limitInfo)
+        public DebuggerSnapshotCreator(bool isFullSnapshot, ProbeLocation location, bool hasCondition, string[] tags, CaptureLimitInfo limitInfo, bool withProcessTags)
         {
             _isFullSnapshot = isFullSnapshot;
             _probeLocation = location;
@@ -55,13 +56,14 @@ public DebuggerSnapshotCreator(bool isFullSnapshot, ProbeLocation location, bool
             ProbeHasCondition = hasCondition;
             Tags = tags;
             _limitInfo = limitInfo;
+            _injectProcessTags = withProcessTags;
             _accumulatedDuration = new TimeSpan(0, 0, 0, 0, 0);
             _scopeMembersPool = new ObjectPool<MethodScopeMembers, MethodScopeMembersParameters>();
             Initialize();
         }
 
-        public DebuggerSnapshotCreator(bool isFullSnapshot, ProbeLocation location, bool hasCondition, string[] tags, MethodScopeMembers methodScopeMembers, CaptureLimitInfo limitInfo)
-            : this(isFullSnapshot, location, hasCondition, tags, limitInfo)
+        public DebuggerSnapshotCreator(bool isFullSnapshot, ProbeLocation location, bool hasCondition, string[] tags, MethodScopeMembers methodScopeMembers, CaptureLimitInfo limitInfo, bool withProcessTags)
+            : this(isFullSnapshot, location, hasCondition, tags, limitInfo, withProcessTags)
         {
             MethodScopeMembers = methodScopeMembers;
         }
@@ -730,7 +732,7 @@ internal void FinalizeSnapshot(string methodName, string typeFullName, string pr
             .EndSnapshot()
             .EndDebugger()
             .AddLoggerInfo(methodName, typeFullName, probeFilePath)
-            .AddGeneralInfo(DebuggerManager.Instance.ServiceName, traceId, spanId)
+            .AddGeneralInfo(DebuggerManager.Instance.ServiceName, ProcessTags.SerializedTags, traceId, spanId)
             .AddMessage()
             .Complete();
         }
@@ -868,11 +870,17 @@ internal DebuggerSnapshotCreator AddLoggerInfo(string methodName, string typeFul
             return this;
         }
 
-        internal DebuggerSnapshotCreator AddGeneralInfo(string service, string traceId, string spanId)
+        internal DebuggerSnapshotCreator AddGeneralInfo(string service, string processTags, string traceId, string spanId)
         {
             JsonWriter.WritePropertyName("service");
             JsonWriter.WriteValue(service ?? UnknownValue);
 
+            if (_injectProcessTags && !string.IsNullOrEmpty(processTags))
+            {
+                JsonWriter.WritePropertyName("process_tags");
+                JsonWriter.WriteValue(processTags);
+            }
+
             JsonWriter.WritePropertyName("ddsource");
             JsonWriter.WriteValue(DebuggerTags.DDSource);
 

tracer/test/Datadog.Trace.Tests/Debugger/DebuggerSnapshotCreatorTests.cs

@@ -96,7 +96,7 @@ public async Task SpecialType_LazyInitialized()
         /// </summary>
         internal async Task ValidateSingleValue(object local)
         {
-            var snapshot = SnapshotHelper.GenerateSnapshot(local);
+            var snapshot = SnapshotHelper.GenerateSnapshot(local, withProcessTags: true);
 
             output.WriteLine("Snapshot: " + snapshot);
             var verifierSettings = new VerifySettings();

tracer/test/Datadog.Trace.Tests/Debugger/SnapshotHelper.cs

@@ -31,23 +31,23 @@ static SnapshotHelper()
         DebuggerSnapshotSerializer.SetConfig(testSettings);
     }
 
-    internal static string GenerateSnapshot(object instance, bool prettify = true)
+    internal static string GenerateSnapshot(object instance, bool prettify = true, bool withProcessTags = false)
     {
-        return GenerateSnapshot(null, new object[] { }, new object[] { instance }, prettify);
+        return GenerateSnapshot(instance: null, new object[] { }, new object[] { instance }, prettify, withProcessTags);
     }
 
     /// <summary>
     /// Generate a debugger snapshot by simulating the same flow of method calls as our instrumentation produces for a method probe.
     /// </summary>
-    private static string GenerateSnapshot(object instance, object[] args, object[] locals, bool prettify)
+    private static string GenerateSnapshot(object instance, object[] args, object[] locals, bool prettify, bool withProcessTags)
     {
         var maxInfo = new CaptureLimitInfo(
             MaxReferenceDepth: DebuggerSettings.DefaultMaxDepthToSerialize,
             MaxCollectionSize: DebuggerSettings.DefaultMaxNumberOfItemsInCollectionToCopy,
             MaxFieldCount: DebuggerSettings.DefaultMaxNumberOfFieldsToCopy,
             MaxLength: DebuggerSettings.DefaultMaxStringLength);
 
-        var snapshotCreator = new DebuggerSnapshotCreator(isFullSnapshot: true, ProbeLocation.Method, hasCondition: false, new[] { "Tag1", "Tag2" }, maxInfo);
+        var snapshotCreator = new DebuggerSnapshotCreator(isFullSnapshot: true, ProbeLocation.Method, hasCondition: false, new[] { "Tag1", "Tag2" }, maxInfo, withProcessTags);
         {
             // method entry
             snapshotCreator.StartEntry();