Start Datadog appender when doing agentless log submission for Log4j2

nikita-tkachenko-datadog · nikita-tkachenko-datadog · commit b4f51c50f20a · 2024-06-11T13:59:58.000+02:00
diff --git a/dd-java-agent/instrumentation/log4j2/logs-intake/src/main/java/datadog/trace/instrumentation/log4j2/LoggerConfigInstrumentation.java b/dd-java-agent/instrumentation/log4j2/logs-intake/src/main/java/datadog/trace/instrumentation/log4j2/LoggerConfigInstrumentation.java
@@ -6,9 +6,11 @@
 import datadog.trace.agent.tooling.Instrumenter;
 import datadog.trace.agent.tooling.InstrumenterModule;
 import datadog.trace.api.Config;
+import java.util.Map;
 import java.util.Set;
 import net.bytebuddy.asm.Advice;
 import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.core.Appender;
 import org.apache.logging.log4j.core.config.LoggerConfig;
 
 @AutoService(InstrumenterModule.class)
@@ -44,7 +46,18 @@ public void methodAdvice(MethodTransformer transformer) {
   public static class LoggerConfigConstructorAdvice {
     @Advice.OnMethodExit(suppress = Throwable.class)
     public static void onExit(@Advice.This LoggerConfig loggerConfig) {
+      Map<String, Appender> appenders = loggerConfig.getAppenders();
+      if (appenders != null) {
+        for (Appender appender : appenders.values()) {
+          if (appender instanceof DatadogAppender) {
+            return;
+          }
+        }
+      }
+
       DatadogAppender appender = new DatadogAppender("datadog", null);
+      appender.start();
+
       Config config = Config.get();
       Level level = Level.valueOf(config.getAgentlessLogSubmissionLevel());
       loggerConfig.addAppender(appender, level, null);
