Implement MDC auto-instrumentation for log4j2

open-telemetry · Sep 16, 2020 · 9d9b54d · 9d9b54d
1 parent e323d3c
commit 9d9b54d
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Showing 7 changed files with 97 additions and 37 deletions.
diff --git a/README.md b/README.md
@@ -204,7 +204,7 @@ provide the path to a JAR file including an SPI implementation using the system
 | [khttp](https://khttp.readthedocs.io)                                                                                                 | 0.1+                           |
 | [Kubernetes Client](https://github.com/kubernetes-client/java)                                                                        | 7.0+                           |
 | [Lettuce](https://github.com/lettuce-io/lettuce-core)                                                                                 | 4.0+                           |
-| [Log4j 2](https://logging.apache.org/log4j/2.x/)                                                                                      | 2.13.2+                        |
+| [Log4j 2](https://logging.apache.org/log4j/2.x/)                                                                                      | 2.7+                           |
 | [Logback](http://logback.qos.ch/)                                                                                                     | 1.0+                           |
 | [MongoDB Drivers](https://mongodb.github.io/mongo-java-driver/)                                                                       | 3.3+                           |
 | [Netty](https://github.com/netty/netty)                                                                                               | 3.8+                           |

diff --git a/instrumentation/log4j/log4j-2-testing/src/main/groovy/Log4j2Test.groovy b/instrumentation/log4j/log4j-2-testing/src/main/groovy/Log4j2Test.groovy
@@ -14,14 +14,14 @@
  * limitations under the License.
  */
 
-import io.opentelemetry.auto.test.AgentTestRunner
+import io.opentelemetry.auto.test.InstrumentationSpecification
 import io.opentelemetry.auto.test.utils.TraceUtils
 import io.opentelemetry.instrumentation.log4j.v2_13_2.ListAppender
 import io.opentelemetry.trace.Span
 import io.opentelemetry.trace.TracingContextUtils
 import org.apache.logging.log4j.LogManager
 
-abstract class Log4j2Test extends AgentTestRunner {
+abstract class Log4j2Test extends InstrumentationSpecification {
   def cleanup() {
     ListAppender.get().clearEvents()
   }

diff --git a/instrumentation/log4j/log4j-2.13.2/auto/src/test/groovy/AutoLog4j2Test.groovy b/instrumentation/log4j/log4j-2.13.2/auto/src/test/groovy/AutoLog4j2Test.groovy
@@ -14,5 +14,7 @@
  * limitations under the License.
  */
 
-class AutoLog4j2Test extends Log4j2Test {
+import io.opentelemetry.auto.test.AgentTestTrait
+
+class AutoLog4j2Test extends Log4j2Test implements AgentTestTrait {
 }
diff --git a/instrumentation/log4j/log4j-2.13.2/library/src/test/groovy/LibraryLog4j2Test.groovy b/instrumentation/log4j/log4j-2.13.2/library/src/test/groovy/LibraryLog4j2Test.groovy
@@ -14,5 +14,7 @@
  * limitations under the License.
  */
 
-class LibraryLog4j2Test extends Log4j2Test {
+import io.opentelemetry.auto.test.InstrumentationTestTrait
+
+class LibraryLog4j2Test extends Log4j2Test implements InstrumentationTestTrait {
 }
diff --git a/...main/java/io/opentelemetry/instrumentation/auto/log4j/v2_7/Log4j27MdcInstrumentation.java b/...main/java/io/opentelemetry/instrumentation/auto/log4j/v2_7/Log4j27MdcInstrumentation.java
@@ -16,76 +16,64 @@
 
 package io.opentelemetry.instrumentation.auto.log4j.v2_7;
 
-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 io.opentelemetry.javaagent.tooling.ClassLoaderMatcher.hasClassesNamed;
-import static io.opentelemetry.javaagent.tooling.bytebuddy.matcher.AgentElementMatchers.implementsInterface;
 import static net.bytebuddy.matcher.ElementMatchers.isMethod;
+import static net.bytebuddy.matcher.ElementMatchers.isPublic;
+import static net.bytebuddy.matcher.ElementMatchers.isStatic;
 import static net.bytebuddy.matcher.ElementMatchers.named;
 import static net.bytebuddy.matcher.ElementMatchers.not;
 import static net.bytebuddy.matcher.ElementMatchers.returns;
 
 import com.google.auto.service.AutoService;
 import io.opentelemetry.javaagent.tooling.Instrumenter;
-import io.opentelemetry.trace.SpanContext;
-import io.opentelemetry.trace.TracingContextUtils;
 import java.util.Collections;
 import java.util.Map;
 import net.bytebuddy.asm.Advice;
 import net.bytebuddy.description.method.MethodDescription;
 import net.bytebuddy.description.type.TypeDescription;
 import net.bytebuddy.implementation.bytecode.assign.Assigner.Typing;
 import net.bytebuddy.matcher.ElementMatcher;
-import org.apache.logging.log4j.util.SortedArrayStringMap;
-import org.apache.logging.log4j.util.StringMap;
+import org.apache.logging.log4j.core.ContextDataInjector;
 
 @AutoService(Instrumenter.class)
 public class Log4j27MdcInstrumentation extends Instrumenter.Default {
   public Log4j27MdcInstrumentation() {
     super("log4j2", "log4j", "log4j-2.7");
   }
 
+  @Override
+  public String[] helperClassNames() {
+    return new String[] {
+      "io.opentelemetry.instrumentation.auto.log4j.v2_7.SpanDecoratingContextDataInjector"
+    };
+  }
+
   @Override
   public ElementMatcher<ClassLoader> classLoaderMatcher() {
     return not(hasClassesNamed("org.apache.logging.log4j.core.util.ContextDataProvider"));
   }
 
   @Override
   public ElementMatcher<? super TypeDescription> typeMatcher() {
-    return implementsInterface(named("org.apache.logging.log4j.core.ContextDataInjector"));
+    return named("org.apache.logging.log4j.core.impl.ContextDataInjectorFactory");
   }
 
   @Override
   public Map<? extends ElementMatcher<? super MethodDescription>, String> transformers() {
     return Collections.singletonMap(
         isMethod()
-            .and(named("injectContextData"))
-            .and(returns(named("org.apache.logging.log4j.util.StringMap"))),
-        Log4j27MdcInstrumentation.class.getName() + "$InjectContextDataAdvice");
+            .and(isPublic())
+            .and(isStatic())
+            .and(named("createInjector"))
+            .and(returns(named("org.apache.logging.log4j.core.ContextDataInjector"))),
+        Log4j27MdcInstrumentation.class.getName() + "$CreateInjectorAdvice");
   }
 
-  public static class InjectContextDataAdvice {
+  public static class CreateInjectorAdvice {
     @Advice.OnMethodExit(suppress = Throwable.class)
     public static void onExit(
-        @Advice.Return(typing = Typing.DYNAMIC, readOnly = false) StringMap contextData) {
-      SpanContext currentContext = TracingContextUtils.getCurrentSpan().getContext();
-      if (!currentContext.isValid()) {
-        return;
-      }
-
-      if (contextData.containsKey(TRACE_ID)) {
-        // Assume already instrumented event if traceId is present.
-        return;
-      }
-
-      StringMap newContextData = new SortedArrayStringMap(contextData);
-      newContextData.putValue(TRACE_ID, currentContext.getTraceIdAsHexString());
-      newContextData.putValue(SPAN_ID, currentContext.getSpanIdAsHexString());
-      if (currentContext.isSampled()) {
-        newContextData.putValue(SAMPLED, "true");
-      }
-      contextData = newContextData;
+        @Advice.Return(typing = Typing.DYNAMIC, readOnly = false) ContextDataInjector injector) {
+      injector = new SpanDecoratingContextDataInjector(injector);
     }
   }
 }
diff --git a/...a/io/opentelemetry/instrumentation/auto/log4j/v2_7/SpanDecoratingContextDataInjector.java b/...a/io/opentelemetry/instrumentation/auto/log4j/v2_7/SpanDecoratingContextDataInjector.java
@@ -0,0 +1,66 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.opentelemetry.instrumentation.auto.log4j.v2_7;
+
+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 io.opentelemetry.trace.SpanContext;
+import io.opentelemetry.trace.TracingContextUtils;
+import java.util.List;
+import org.apache.logging.log4j.core.ContextDataInjector;
+import org.apache.logging.log4j.core.config.Property;
+import org.apache.logging.log4j.util.ReadOnlyStringMap;
+import org.apache.logging.log4j.util.SortedArrayStringMap;
+import org.apache.logging.log4j.util.StringMap;
+
+public final class SpanDecoratingContextDataInjector implements ContextDataInjector {
+  private final ContextDataInjector delegate;
+
+  public SpanDecoratingContextDataInjector(ContextDataInjector delegate) {
+    this.delegate = delegate;
+  }
+
+  @Override
+  public StringMap injectContextData(List<Property> list, StringMap stringMap) {
+    StringMap contextData = delegate.injectContextData(list, stringMap);
+
+    if (contextData.containsKey(TRACE_ID)) {
+      // Assume already instrumented event if traceId is present.
+      return contextData;
+    }
+
+    SpanContext currentContext = TracingContextUtils.getCurrentSpan().getContext();
+    if (!currentContext.isValid()) {
+      return contextData;
+    }
+
+    StringMap newContextData = new SortedArrayStringMap(contextData);
+    newContextData.putValue(TRACE_ID, currentContext.getTraceIdAsHexString());
+    newContextData.putValue(SPAN_ID, currentContext.getSpanIdAsHexString());
+    if (currentContext.isSampled()) {
+      newContextData.putValue(SAMPLED, "true");
+    }
+    return newContextData;
+  }
+
+  @Override
+  public ReadOnlyStringMap rawContextData() {
+    return delegate.rawContextData();
+  }
+}
diff --git a/instrumentation/log4j/log4j-2.7/src/test/groovy/Log4j27Test.groovy b/instrumentation/log4j/log4j-2.7/src/test/groovy/Log4j27Test.groovy
@@ -14,5 +14,7 @@
  * limitations under the License.
  */
 
-class Log4j27Test extends Log4j2Test {
+import io.opentelemetry.auto.test.AgentTestTrait
+
+class Log4j27Test extends Log4j2Test implements AgentTestTrait {
 }