Add process tags to runtime metrics & dynamic instrumentation metric probes

tracer/src/Datadog.Trace/Debugger/DebuggerFactory.cs

@@ -72,6 +72,7 @@ private static IDogStatsd GetDogStatsd(TracerSettings tracerSettings, string ser
                 tracerSettings.Manager.InitialMutableSettings,
                 tracerSettings.Manager.InitialExporterSettings,
                 includeDefaultTags: false,
+                tracerSettings.PropagateProcessTags ? ProcessTags.TagsList : [],
                 prefix: DebuggerSettings.DebuggerMetricPrefix);
         }
 

tracer/src/Datadog.Trace/DogStatsd/StatsdFactory.cs

@@ -18,19 +18,19 @@ internal static class StatsdFactory
 {
     private static readonly IDatadogLogger Log = DatadogLogging.GetLoggerFor(typeof(StatsdFactory));
 
-    internal static IDogStatsd CreateDogStatsdClient(MutableSettings settings, ExporterSettings exporter, bool includeDefaultTags, string? prefix = null)
+    internal static IDogStatsd CreateDogStatsdClient(MutableSettings settings, ExporterSettings exporter, bool includeDefaultTags, IList<string> processTags, string? prefix = null)
     {
+        var customTagCount = settings.GlobalTags.Count;
+        var tagsCount = (includeDefaultTags ? 5 + customTagCount : 0) + processTags.Count;
+        var constantTags = new List<string>(tagsCount);
         if (includeDefaultTags)
         {
-            var customTagCount = settings.GlobalTags.Count;
-            var constantTags = new List<string>(5 + customTagCount)
-            {
-                "lang:.NET",
-                $"lang_interpreter:{FrameworkDescription.Instance.Name}",
-                $"lang_version:{FrameworkDescription.Instance.ProductVersion}",
-                $"tracer_version:{TracerConstants.AssemblyVersion}",
-                $"{Tags.RuntimeId}:{Tracer.RuntimeId}"
-            };
+            constantTags.Add("lang:.NET");
+            constantTags.Add($"lang_interpreter:{FrameworkDescription.Instance.Name}");
+            constantTags.Add($"lang_version:{FrameworkDescription.Instance.ProductVersion}");
+            constantTags.Add($"tracer_version:{TracerConstants.AssemblyVersion}");
+            constantTags.Add($"{Tags.RuntimeId}:{Tracer.RuntimeId}");
+            // update count above if adding new tags
 
             if (customTagCount > 0)
             {
@@ -43,11 +43,14 @@ internal static IDogStatsd CreateDogStatsdClient(MutableSettings settings, Expor
                     constantTags.Add($"{key}:{value}");
                 }
             }
+        }
 
-            return CreateDogStatsdClient(settings, exporter, constantTags, prefix);
+        if (processTags.Count > 0)
+        {
+            constantTags.AddRange(processTags);
         }
 
-        return CreateDogStatsdClient(settings, exporter, constantTags: null, prefix);
+        return CreateDogStatsdClient(settings, exporter, constantTags, prefix);
     }
 
     private static IDogStatsd CreateDogStatsdClient(MutableSettings settings, ExporterSettings exporter, List<string>? constantTags, string? prefix = null)

tracer/src/Datadog.Trace/DogStatsd/StatsdManager.cs

@@ -6,6 +6,7 @@
 #nullable enable
 
 using System;
+using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
 using Datadog.Trace.Configuration;
@@ -33,12 +34,13 @@ public StatsdManager(TracerSettings tracerSettings)
     }
 
     // Internal for testing
-    internal StatsdManager(TracerSettings tracerSettings, Func<MutableSettings, ExporterSettings, StatsdClientHolder> statsdFactory)
+    internal StatsdManager(TracerSettings tracerSettings, Func<MutableSettings, ExporterSettings, IList<string>, StatsdClientHolder> statsdFactory)
     {
         // The initial factory, assuming there's no updates
         _factory = () => statsdFactory(
             tracerSettings.Manager.InitialMutableSettings,
-            tracerSettings.Manager.InitialExporterSettings);
+            tracerSettings.Manager.InitialExporterSettings,
+            tracerSettings.PropagateProcessTags ? ProcessTags.TagsList : []);
 
         // We don't create a new client unless we need one, and we rely on consumers of the manager to tell us when it's needed
         _current = null;
@@ -60,7 +62,8 @@ internal StatsdManager(TracerSettings tracerSettings, Func<MutableSettings, Expo
                 ref _factory,
                 () => statsdFactory(
                     c.UpdatedMutable ?? c.PreviousMutable,
-                    c.UpdatedExporter ?? c.PreviousExporter));
+                    c.UpdatedExporter ?? c.PreviousExporter,
+                    tracerSettings.PropagateProcessTags ? ProcessTags.TagsList : []));
 
             // check if we actually need to do an update or if noone is using the client yet
             if (Volatile.Read(ref _isRequiredMask) != 0)
@@ -173,8 +176,10 @@ internal static bool HasImpactingChanges(TracerSettings.SettingsManager.SettingC
         return hasChanges;
     }
 
-    private static StatsdClientHolder CreateClient(MutableSettings settings, ExporterSettings exporter)
-        => new(StatsdFactory.CreateDogStatsdClient(settings, exporter, includeDefaultTags: true));
+    private static StatsdClientHolder CreateClient(MutableSettings settings, ExporterSettings exporter, IList<string> processTags)
+    {
+        return new StatsdClientHolder(StatsdFactory.CreateDogStatsdClient(settings, exporter, includeDefaultTags: true, processTags));
+    }
 
     private void EnsureClient(bool ensureCreated, bool forceRecreate)
     {

tracer/src/Datadog.Trace/ProcessTags.cs

@@ -7,10 +7,10 @@
 
 using System;
 using System.Collections.Generic;
+using System.Collections.ObjectModel;
 using System.IO;
 using Datadog.Trace.Configuration;
 using Datadog.Trace.Processors;
-using Datadog.Trace.Util;
 
 namespace Datadog.Trace;
 
@@ -21,7 +21,7 @@ internal static class ProcessTags
     public const string EntrypointWorkdir = "entrypoint.workdir";
 
     // two views on the same data
-    public static readonly List<string> TagsList = GetTagsList();
+    public static readonly ReadOnlyCollection<string> TagsList = GetTagsList().AsReadOnly();
     public static readonly string SerializedTags = GetSerializedTagsFromList(TagsList);
 
     private static List<string> GetTagsList()
@@ -53,7 +53,7 @@ private static void AddNormalizedTag(this List<string> tags, string key, string?
         tags.Add($"{key}:{normalizedValue}");
     }
 
-    private static string GetSerializedTagsFromList(List<string> tags)
+    private static string GetSerializedTagsFromList(IEnumerable<string> tags)
     {
         return string.Join(",", tags);
     }

tracer/src/Datadog.Trace/RemoteConfigurationManagement/Protocol/RcmClientTracer.cs

@@ -10,15 +10,13 @@
 using System.Linq;
 using Datadog.Trace.Vendors.Newtonsoft.Json;
 
-#nullable enable
-
 namespace Datadog.Trace.RemoteConfigurationManagement.Protocol
 {
     internal sealed class RcmClientTracer
     {
         // Don't change this constructor - it's used by Newtonsoft.JSON for deserialization
         // and that can mean the provided properties are not _really_ nullable, even though we "require" them to be
-        public RcmClientTracer(string runtimeId, string tracerVersion, string service, string env, string? appVersion, List<string> tags, List<string>? processTags)
+        public RcmClientTracer(string runtimeId, string tracerVersion, string service, string env, string? appVersion, List<string> tags, IList<string>? processTags)
         {
             RuntimeId = runtimeId;
             Language = TracerConstants.Language;
@@ -46,7 +44,7 @@ public RcmClientTracer(string runtimeId, string tracerVersion, string service, s
         public string? Service { get; }
 
         [JsonProperty("process_tags")]
-        public List<string>? ProcessTags { get; }
+        public IList<string>? ProcessTags { get; }
 
         [JsonProperty("extra_services")]
         public string[]? ExtraServices { get; set; }
@@ -60,7 +58,7 @@ public RcmClientTracer(string runtimeId, string tracerVersion, string service, s
         [JsonProperty("tags")]
         public List<string> Tags { get; }
 
-        public static RcmClientTracer Create(string runtimeId, string tracerVersion, string service, string env, string? appVersion, ReadOnlyDictionary<string, string> globalTags, List<string>? processTags)
+        public static RcmClientTracer Create(string runtimeId, string tracerVersion, string service, string env, string? appVersion, ReadOnlyDictionary<string, string> globalTags, IList<string>? processTags)
             => new(runtimeId, tracerVersion, service, env, appVersion, GetTags(env, service, globalTags), processTags);
 
         private static List<string> GetTags(string? environment, string? serviceVersion, ReadOnlyDictionary<string, string>? globalTags)

tracer/src/Datadog.Trace/RemoteConfigurationManagement/RemoteConfigurationManager.cs

@@ -42,7 +42,7 @@ private RemoteConfigurationManager(
             TimeSpan pollInterval,
             IGitMetadataTagsProvider gitMetadataTagsProvider,
             IRcmSubscriptionManager subscriptionManager,
-            List<string>? processTags)
+            IList<string>? processTags)
         {
             _discoveryService = discoveryService;
             _pollInterval = pollInterval;

tracer/test/Datadog.Trace.ClrProfiler.IntegrationTests/RuntimeMetricsTests.cs

@@ -82,6 +82,60 @@ public async Task NamedPipesSubmitsMetrics()
             await RunTest();
         }
 
+        [SkippableFact]
+        [Trait("Category", "EndToEnd")]
+        [Trait("RunOnWindows", "True")]
+        public async Task ProcessTagsIncludedInMetrics_WhenEnabled()
+        {
+            SkipOn.Platform(SkipOn.PlatformValue.MacOs);
+            EnvironmentHelper.EnableDefaultTransport();
+            SetEnvironmentVariable("DD_RUNTIME_METRICS_ENABLED", "1");
+            SetEnvironmentVariable("DD_EXPERIMENTAL_PROPAGATE_PROCESS_TAGS_ENABLED", "1");
+            SetEnvironmentVariable("DD_SERVICE", "Samples.RuntimeMetrics");
+
+            using var agent = EnvironmentHelper.GetMockAgent(useStatsD: true);
+            using var processResult = await RunSampleAndWaitForExit(agent);
+            var requests = agent.StatsdRequests;
+
+            Assert.True(requests.Count > 0, "No metrics received");
+
+            var metrics = requests.SelectMany(x => x.Split('\n')).ToList();
+
+            // Verify process tags are present in the metrics
+            // Process tags include: entrypoint.basedir, entrypoint.workdir, and optionally entrypoint.name
+            metrics
+               .Should()
+               .OnlyContain(s => s.Contains("entrypoint.basedir:"), "entrypoint.basedir process tag should be present")
+               .And.OnlyContain(s => s.Contains("entrypoint.workdir:"), "entrypoint.workdir process tag should be present");
+        }
+
+        [SkippableFact]
+        [Trait("Category", "EndToEnd")]
+        [Trait("RunOnWindows", "True")]
+        public async Task ProcessTagsNotIncludedInMetrics_WhenDisabled()
+        {
+            SkipOn.Platform(SkipOn.PlatformValue.MacOs);
+            EnvironmentHelper.EnableDefaultTransport();
+            SetEnvironmentVariable("DD_RUNTIME_METRICS_ENABLED", "1");
+            SetEnvironmentVariable("DD_EXPERIMENTAL_PROPAGATE_PROCESS_TAGS_ENABLED", "0");
+            SetEnvironmentVariable("DD_SERVICE", "Samples.RuntimeMetrics");
+
+            using var agent = EnvironmentHelper.GetMockAgent(useStatsD: true);
+            using var processResult = await RunSampleAndWaitForExit(agent);
+            var requests = agent.StatsdRequests;
+
+            Assert.True(requests.Count > 0, "No metrics received");
+
+            var metrics = requests.SelectMany(x => x.Split('\n')).ToList();
+
+            // Verify process tags are NOT present in the metrics when disabled
+            metrics
+               .Should()
+               .NotContain(s => s.Contains("entrypoint.basedir:"), "entrypoint.basedir should not be present when process tags are disabled")
+               .And.NotContain(s => s.Contains("entrypoint.workdir:"), "entrypoint.workdir should not be present when process tags are disabled")
+               .And.NotContain(s => s.Contains("entrypoint.name:"), "entrypoint.name should not be present when process tags are disabled");
+        }
+
         private async Task RunTest()
         {
             var inputServiceName = "12_$#Samples.$RuntimeMetrics";

tracer/test/Datadog.Trace.Tests/DogStatsDTests.cs

@@ -139,6 +139,7 @@ public void CanCreateDogStatsD_UDP_FromTraceAgentSettings(string agentUri, strin
                 settings.Manager.InitialMutableSettings,
                 settings.Manager.InitialExporterSettings,
                 includeDefaultTags: true,
+                processTags: ["a:b", "c:d"],
                 prefix: null);
 
             // If there's an error during configuration, we get a no-op instance, so using this as a test
@@ -168,6 +169,7 @@ public void CanCreateDogStatsD_NamedPipes_FromTraceAgentSettings()
                 settings.Manager.InitialMutableSettings,
                 settings.Manager.InitialExporterSettings,
                 includeDefaultTags: true,
+                processTags: ["a:b", "c:d"],
                 prefix: null);
 
             // If there's an error during configuration, we get a no-op instance, so using this as a test
@@ -202,6 +204,7 @@ public void CanCreateDogStatsD_UDS_FromTraceAgentSettings()
                 settings.Manager.InitialMutableSettings,
                 settings.Manager.InitialExporterSettings,
                 includeDefaultTags: true,
+                processTags: ["a:b", "c:d"],
                 prefix: null);
 
             // If there's an error during configuration, we get a no-op instance, so using this as a test
@@ -234,6 +237,7 @@ public void CanCreateDogStatsD_UDS_FallsBackToUdp_FromTraceAgentSettings()
                 settings.Manager.InitialMutableSettings,
                 settings.Manager.InitialExporterSettings,
                 includeDefaultTags: true,
+                processTags: ["a:b", "c:d"],
                 prefix: null);
 
             // If there's an error during configuration, we get a no-op instance, so using this as a test