Implement MDC auto-instrumentation for log4j2

open-telemetry · Sep 17, 2020 · 049850e · 049850e
1 parent d2ce072
commit 049850e
Showing 1 changed file with 11 additions and 8 deletions.
diff --git a/...a/io/opentelemetry/instrumentation/auto/log4j/v1_2/Log4j1LoggingEventInstrumentation.java b/...a/io/opentelemetry/instrumentation/auto/log4j/v1_2/Log4j1LoggingEventInstrumentation.java
@@ -16,6 +16,9 @@
 
 package io.opentelemetry.instrumentation.auto.log4j.v1_2;
 
+import static io.opentelemetry.instrumentation.api.log.LoggingContextConstants.SAMPLED;
+import static io.opentelemetry.instrumentation.api.log.LoggingContextConstants.SPAN_ID;
+import static io.opentelemetry.instrumentation.api.log.LoggingContextConstants.TRACE_ID;
 import static java.util.Collections.singletonMap;
 import static net.bytebuddy.matcher.ElementMatchers.isMethod;
 import static net.bytebuddy.matcher.ElementMatchers.isPublic;
@@ -79,7 +82,7 @@ public static void onExit(
         @Advice.This LoggingEvent event,
         @Advice.Argument(0) String key,
         @Advice.Return(readOnly = false) Object value) {
-      if ("traceId".equals(key) || "spanId".equals(key) || "sampled".equals(key)) {
+      if (TRACE_ID.equals(key) || SPAN_ID.equals(key) || SAMPLED.equals(key)) {
         if (value != null) {
           // Assume already instrumented event if traceId/spanId/sampled is present.
           return;
@@ -92,13 +95,13 @@ public static void onExit(
 
         SpanContext spanContext = span.getContext();
         switch (key) {
-          case "traceId":
+          case TRACE_ID:
             value = spanContext.getTraceIdAsHexString();
             break;
-          case "spanId":
+          case SPAN_ID:
             value = spanContext.getSpanIdAsHexString();
             break;
-          case "sampled":
+          case SAMPLED:
             if (spanContext.isSampled()) {
               value = "true";
             }
@@ -128,14 +131,14 @@ public static void onEnter(
         }
 
         // Assume already instrumented event if traceId is present.
-        if (!mdc.contains("traceId")) {
+        if (!mdc.contains(TRACE_ID)) {
           Span span = InstrumentationContext.get(LoggingEvent.class, Span.class).get(event);
           if (span != null && span.getContext().isValid()) {
             SpanContext spanContext = span.getContext();
-            mdc.put("traceId", spanContext.getTraceIdAsHexString());
-            mdc.put("spanId", spanContext.getSpanIdAsHexString());
+            mdc.put(TRACE_ID, spanContext.getTraceIdAsHexString());
+            mdc.put(SPAN_ID, spanContext.getSpanIdAsHexString());
             if (spanContext.isSampled()) {
-              mdc.put("sampled", "true");
+              mdc.put(SAMPLED, "true");
             }
           }
         }