Introducing DD_TRACE_EXPERIMENTAL_FEATURES_ENABLED Config (#8536)

* introducing config

* undo spotless

Author: mhlidd

dd-trace-api/src/main/java/datadog/trace/api/ConfigDefaults.java

@@ -232,6 +232,8 @@ public final class ConfigDefaults {
   static final boolean DEFAULT_TELEMETRY_LOG_COLLECTION_ENABLED = true;
   static final int DEFAULT_TELEMETRY_DEPENDENCY_RESOLUTION_QUEUE_SIZE = 100000;
 
+  static final Set<String> DEFAULT_TRACE_EXPERIMENTAL_FEATURES_ENABLED = new HashSet<>();
+
   static final boolean DEFAULT_TRACE_128_BIT_TRACEID_GENERATION_ENABLED = true;
   static final boolean DEFAULT_TRACE_128_BIT_TRACEID_LOGGING_ENABLED = false;
   static final boolean DEFAULT_SECURE_RANDOM = false;

dd-trace-api/src/main/java/datadog/trace/api/config/TracerConfig.java

@@ -34,6 +34,9 @@ public final class TracerConfig {
   @Deprecated public static final String TRACE_RESOLVER_ENABLED = "trace.resolver.enabled";
   public static final String SERVICE_MAPPING = "service.mapping";
 
+  public static final String TRACE_EXPERIMENTAL_FEATURES_ENABLED =
+      "trace.experimental.features.enabled";
+
   public static final String SPAN_TAGS = "trace.span.tags";
   public static final String TRACE_ANALYTICS_ENABLED = "trace.analytics.enabled";
 

internal-api/src/main/java/datadog/trace/api/Config.java

@@ -561,6 +561,7 @@ public static String getHostName() {
   private final long dependecyResolutionPeriodMillis;
 
   private final boolean apmTracingEnabled;
+  private final Set<String> experimentalFeaturesEnabled;
 
   // Read order: System Properties -> Env Variables, [-> properties file], [-> default value]
   private Config() {
@@ -626,6 +627,10 @@ private Config(final ConfigProvider configProvider, final InstrumenterConfig ins
         configProvider.getString(
             SERVLET_ROOT_CONTEXT_SERVICE_NAME, DEFAULT_SERVLET_ROOT_CONTEXT_SERVICE_NAME);
 
+    experimentalFeaturesEnabled =
+        configProvider.getSet(
+            TRACE_EXPERIMENTAL_FEATURES_ENABLED, DEFAULT_TRACE_EXPERIMENTAL_FEATURES_ENABLED);
+
     integrationSynapseLegacyOperationName =
         configProvider.getBoolean(INTEGRATION_SYNAPSE_LEGACY_OPERATION_NAME, false);
     writerType = configProvider.getString(WRITER_TYPE, DEFAULT_AGENT_WRITER_TYPE);
@@ -2013,6 +2018,10 @@ public String getRootContextServiceName() {
     return rootContextServiceName;
   }
 
+  public Set<String> getExperimentalFeaturesEnabled() {
+    return experimentalFeaturesEnabled;
+  }
+
   public boolean isTraceEnabled() {
     return instrumenterConfig.isTraceEnabled();
   }
@@ -4367,6 +4376,8 @@ public String toString() {
         + serviceNameSetByUser
         + ", rootContextServiceName="
         + rootContextServiceName
+        + ", experimentalFeaturesEnabled="
+        + experimentalFeaturesEnabled
         + ", integrationSynapseLegacyOperationName="
         + integrationSynapseLegacyOperationName
         + ", writerType='"

internal-api/src/test/groovy/datadog/trace/api/ConfigTest.groovy

@@ -107,6 +107,7 @@ import static datadog.trace.api.config.TracerConfig.HTTP_CLIENT_ERROR_STATUSES
 import static datadog.trace.api.config.TracerConfig.HTTP_SERVER_ERROR_STATUSES
 import static datadog.trace.api.config.TracerConfig.ID_GENERATION_STRATEGY
 import static datadog.trace.api.config.TracerConfig.PARTIAL_FLUSH_ENABLED
+import static datadog.trace.api.config.TracerConfig.TRACE_EXPERIMENTAL_FEATURES_ENABLED
 import static datadog.trace.api.config.TracerConfig.TRACE_LONG_RUNNING_ENABLED
 import static datadog.trace.api.config.TracerConfig.TRACE_LONG_RUNNING_FLUSH_INTERVAL
 import static datadog.trace.api.config.TracerConfig.TRACE_LONG_RUNNING_INITIAL_FLUSH_INTERVAL
@@ -221,6 +222,8 @@ class ConfigTest extends DDSpecification {
     prop.setProperty(TRACE_LONG_RUNNING_ENABLED, "true")
     prop.setProperty(TRACE_LONG_RUNNING_FLUSH_INTERVAL, "250")
 
+    prop.setProperty(TRACE_EXPERIMENTAL_FEATURES_ENABLED, "DD_TAGS, DD_TRACE_HTTP_CLIENT_TAG_QUERY_STRING")
+
     prop.setProperty(PROFILING_ENABLED, "true")
     prop.setProperty(PROFILING_URL, "new url")
     prop.setProperty(PROFILING_TAGS, "f:6,host:test-host")
@@ -312,6 +315,8 @@ class ConfigTest extends DDSpecification {
     config.isLongRunningTraceEnabled()
     config.getLongRunningTraceFlushInterval() == 250
 
+    config.experimentalFeaturesEnabled == ["DD_TAGS", "DD_TRACE_HTTP_CLIENT_TAG_QUERY_STRING"].toSet()
+
     config.profilingEnabled == true
     config.profilingUrl == "new url"
     config.mergedProfilingTags == [b: "2", f: "6", (HOST_TAG): "test-host", (RUNTIME_ID_TAG): config.getRuntimeId(), (RUNTIME_VERSION_TAG): config.getRuntimeVersion(), (SERVICE_TAG): config.serviceName, (LANGUAGE_TAG_KEY): LANGUAGE_TAG_VALUE]
@@ -402,6 +407,8 @@ class ConfigTest extends DDSpecification {
     System.setProperty(PREFIX + TRACE_LONG_RUNNING_ENABLED, "true")
     System.setProperty(PREFIX + TRACE_LONG_RUNNING_FLUSH_INTERVAL, "333")
 
+    System.setProperty(PREFIX + TRACE_EXPERIMENTAL_FEATURES_ENABLED, "DD_TAGS, DD_TRACE_HTTP_CLIENT_TAG_QUERY_STRING")
+
     System.setProperty(PREFIX + PROFILING_ENABLED, "true")
     System.setProperty(PREFIX + PROFILING_URL, "new url")
     System.setProperty(PREFIX + PROFILING_TAGS, "f:6,host:test-host")
@@ -493,6 +500,8 @@ class ConfigTest extends DDSpecification {
     config.getLongRunningTraceFlushInterval() == 333
     config.traceRateLimit == 200
 
+    config.experimentalFeaturesEnabled == ["DD_TAGS", "DD_TRACE_HTTP_CLIENT_TAG_QUERY_STRING"].toSet()
+
     config.profilingEnabled == true
     config.profilingUrl == "new url"
     config.mergedProfilingTags == [b: "2", f: "6", (HOST_TAG): "test-host", (RUNTIME_ID_TAG): config.getRuntimeId(), (RUNTIME_VERSION_TAG): config.getRuntimeVersion(), (SERVICE_TAG): config.serviceName, (LANGUAGE_TAG_KEY): LANGUAGE_TAG_VALUE]