Add Baggage to logback MDC controlled by flag

instrumentation/logback/logback-mdc-1.0/javaagent/build.gradle.kts

@@ -10,6 +10,42 @@ muzzle {
   }
 }
 
+testing {
+  suites {
+    val addBaggageTest by registering(JvmTestSuite::class) {
+      targets {
+        all {
+          testTask.configure {
+            jvmArgs("-Dotel.instrumentation.logback-mdc.add-baggage=true")
+          }
+        }
+      }
+    }
+
+    withType(JvmTestSuite::class) {
+      dependencies {
+        if (findProperty("testLatestDeps") as Boolean) {
+          implementation("ch.qos.logback:logback-classic:+")
+        } else {
+          implementation("ch.qos.logback:logback-classic") {
+            version {
+              strictly("1.0.0")
+            }
+          }
+          implementation("org.slf4j:slf4j-api") {
+            version {
+              strictly("1.6.4")
+            }
+          }
+        }
+
+        implementation(project(":instrumentation:logback:logback-mdc-1.0:testing"))
+        implementation(project(":instrumentation:logback:logback-mdc-1.0:javaagent"))
+      }
+    }
+  }
+}
+
 dependencies {
   implementation(project(":instrumentation:logback:logback-mdc-1.0:library"))
 
@@ -24,21 +60,10 @@ dependencies {
       strictly("1.6.4")
     }
   }
+}
 
-  if (findProperty("testLatestDeps") as Boolean) {
-    testImplementation("ch.qos.logback:logback-classic:+")
-  } else {
-    testImplementation("ch.qos.logback:logback-classic") {
-      version {
-        strictly("1.0.0")
-      }
-    }
-    testImplementation("org.slf4j:slf4j-api") {
-      version {
-        strictly("1.6.4")
-      }
-    }
+tasks {
+  named("check") {
+    dependsOn(testing.suites)
   }
-
-  testImplementation(project(":instrumentation:logback:logback-mdc-1.0:testing"))
 }

instrumentation/logback/logback-mdc-1.0/javaagent/src/addBaggageTest/groovy/io/opentelemetry/javaagent/instrumentation/logback/v1_0/LogbackWithBaggageTest.groovy

@@ -0,0 +1,12 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.javaagent.instrumentation.logback.v1_0
+
+import io.opentelemetry.instrumentation.logback.mdc.v1_0.AbstractLogbackWithBaggageTest
+import io.opentelemetry.instrumentation.test.AgentTestTrait
+
+class LogbackWithBaggageTest extends AbstractLogbackWithBaggageTest implements AgentTestTrait {
+}

instrumentation/logback/logback-mdc-1.0/javaagent/src/addBaggageTest/resources/logback.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+  <appender name="LIST" class="ch.qos.logback.core.read.ListAppender" />
+
+  <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+    <encoder>
+      <pattern>%coloredLevel %logger{15} - %message%n%xException{10}</pattern>
+    </encoder>
+  </appender>
+
+  <logger name="test">
+    <level value="info" />
+    <appender-ref ref="LIST" />
+  </logger>
+
+  <root level="debug">
+    <appender-ref ref="STDOUT" />
+  </root>
+</configuration>

instrumentation/logback/logback-mdc-1.0/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/logback/mdc/v1_0/LogbackSingletons.java

@@ -0,0 +1,19 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.javaagent.instrumentation.logback.mdc.v1_0;
+
+import io.opentelemetry.instrumentation.api.internal.ConfigPropertiesUtil;
+
+public final class LogbackSingletons {
+  private static final boolean ADD_BAGGAGE =
+      ConfigPropertiesUtil.getBoolean("otel.instrumentation.logback-mdc.add-baggage", false);
+
+  public static boolean addBaggage() {
+    return ADD_BAGGAGE;
+  }
+
+  private LogbackSingletons() {}
+}

instrumentation/logback/logback-mdc-1.0/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/logback/mdc/v1_0/LoggingEventInstrumentation.java

@@ -17,6 +17,8 @@
 import static net.bytebuddy.matcher.ElementMatchers.takesArguments;
 
 import ch.qos.logback.classic.spi.ILoggingEvent;
+import io.opentelemetry.api.baggage.Baggage;
+import io.opentelemetry.api.baggage.BaggageEntry;
 import io.opentelemetry.api.trace.SpanContext;
 import io.opentelemetry.context.Context;
 import io.opentelemetry.instrumentation.api.util.VirtualField;
@@ -54,11 +56,11 @@ public void transform(TypeTransformer transformer) {
 
   @SuppressWarnings("unused")
   public static class GetMdcAdvice {
-
     @Advice.OnMethodExit(suppress = Throwable.class)
     public static void onExit(
         @Advice.This ILoggingEvent event,
         @Advice.Return(typing = Typing.DYNAMIC, readOnly = false) Map<String, String> contextData) {
+
       if (contextData != null && contextData.containsKey(TRACE_ID)) {
         // Assume already instrumented event if traceId is present.
         return;
@@ -69,15 +71,28 @@ public static void onExit(
         return;
       }
 
+      Map<String, String> spanContextData = new HashMap<>();
+
       SpanContext spanContext = Java8BytecodeBridge.spanFromContext(context).getSpanContext();
-      if (!spanContext.isValid()) {
-        return;
+
+      if (spanContext.isValid()) {
+        spanContextData.put(TRACE_ID, spanContext.getTraceId());
+        spanContextData.put(SPAN_ID, spanContext.getSpanId());
+        spanContextData.put(TRACE_FLAGS, spanContext.getTraceFlags().asHex());
       }
 
-      Map<String, String> spanContextData = new HashMap<>();
-      spanContextData.put(TRACE_ID, spanContext.getTraceId());
-      spanContextData.put(SPAN_ID, spanContext.getSpanId());
-      spanContextData.put(TRACE_FLAGS, spanContext.getTraceFlags().asHex());
+      if (LogbackSingletons.addBaggage()) {
+        Baggage baggage = Java8BytecodeBridge.baggageFromContext(context);
+
+        // using a lambda here does not play nicely with instrumentation bytecode process
+        // (Java 6 related errors are observed) so relying on for loop instead
+        for (Map.Entry<String, BaggageEntry> entry : baggage.asMap().entrySet()) {
+          spanContextData.put(
+              entry.getKey(),
+              // prefix all baggage values to avoid clashes with existing context
+              "baggage." + entry.getValue().getValue());
+        }
+      }
 
       if (contextData == null) {
         contextData = spanContextData;

instrumentation/logback/logback-mdc-1.0/library/build.gradle.kts

@@ -2,7 +2,44 @@ plugins {
   id("otel.library-instrumentation")
 }
 
+testing {
+  suites {
+    val addBaggageTest by registering(JvmTestSuite::class) {
+      targets {
+        all {
+          testTask.configure {
+            jvmArgs("-Dotel.instrumentation.logback-mdc.add-baggage=true")
+          }
+        }
+      }
+    }
+
+    withType(JvmTestSuite::class) {
+      dependencies {
+        if (findProperty("testLatestDeps") as Boolean) {
+          implementation("ch.qos.logback:logback-classic:+")
+        } else {
+          implementation("ch.qos.logback:logback-classic") {
+            version {
+              strictly("1.0.0")
+            }
+          }
+          implementation("org.slf4j:slf4j-api") {
+            version {
+              strictly("1.6.4")
+            }
+          }
+        }
+
+        implementation(project(":instrumentation:logback:logback-mdc-1.0:testing"))
+        implementation(project(":instrumentation:logback:logback-mdc-1.0:library"))
+      }
+    }
+  }
+}
+
 dependencies {
+
   // pin the version strictly to avoid overriding by dependencyManagement versions
   compileOnly("ch.qos.logback:logback-classic") {
     version {
@@ -14,21 +51,10 @@ dependencies {
       strictly("1.6.4")
     }
   }
+}
 
-  if (findProperty("testLatestDeps") as Boolean) {
-    testImplementation("ch.qos.logback:logback-classic:+")
-  } else {
-    testImplementation("ch.qos.logback:logback-classic") {
-      version {
-        strictly("1.0.0")
-      }
-    }
-    testImplementation("org.slf4j:slf4j-api") {
-      version {
-        strictly("1.6.4")
-      }
-    }
+tasks {
+  named("check") {
+    dependsOn(testing.suites)
   }
-
-  testImplementation(project(":instrumentation:logback:logback-mdc-1.0:testing"))
 }

instrumentation/logback/logback-mdc-1.0/library/src/addBaggageTest/groovy/io/opentelemetry/instrumentation/logback/mdc/v1_0/LogbackWithBaggageTest.groovy

@@ -0,0 +1,12 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.instrumentation.logback.mdc.v1_0
+
+
+import io.opentelemetry.instrumentation.test.LibraryTestTrait
+
+class LogbackWithBaggageTest extends AbstractLogbackWithBaggageTest implements LibraryTestTrait {
+}

instrumentation/logback/logback-mdc-1.0/library/src/addBaggageTest/resources/logback.xml

@@ -0,0 +1,31 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ 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.
+  -->
+
+<configuration>
+  <appender name="LIST" class="ch.qos.logback.core.read.ListAppender"/>
+
+  <appender name="OTEL"
+    class="io.opentelemetry.instrumentation.logback.mdc.v1_0.OpenTelemetryAppender">
+    <addBaggage>true</addBaggage>
+    <appender-ref ref="LIST"/>
+  </appender>
+
+  <logger name="test">
+    <level value="info"/>
+    <appender-ref ref="OTEL"/>
+  </logger>
+</configuration>

instrumentation/logback/logback-mdc-1.0/library/src/main/java/io/opentelemetry/instrumentation/logback/mdc/v1_0/OpenTelemetryAppender.java

@@ -15,8 +15,10 @@
 import ch.qos.logback.core.UnsynchronizedAppenderBase;
 import ch.qos.logback.core.spi.AppenderAttachable;
 import ch.qos.logback.core.spi.AppenderAttachableImpl;
+import io.opentelemetry.api.baggage.Baggage;
 import io.opentelemetry.api.trace.Span;
 import io.opentelemetry.api.trace.SpanContext;
+import io.opentelemetry.context.Context;
 import io.opentelemetry.instrumentation.logback.mdc.v1_0.internal.UnionMap;
 import java.lang.reflect.Proxy;
 import java.util.HashMap;
@@ -25,26 +27,48 @@
 
 public class OpenTelemetryAppender extends UnsynchronizedAppenderBase<ILoggingEvent>
     implements AppenderAttachable<ILoggingEvent> {
+  private volatile boolean addBaggage;
 
   private final AppenderAttachableImpl<ILoggingEvent> aai = new AppenderAttachableImpl<>();
 
-  public static ILoggingEvent wrapEvent(ILoggingEvent event) {
-    Span currentSpan = Span.current();
-    if (!currentSpan.getSpanContext().isValid()) {
-      return event;
-    }
+  /**
+   * When set to true this will enable addition of all baggage entries to MDC. This can be done by
+   * adding the following to the logback.xml config for this appender. {@code
+   * <addBaggage>true</addBaggage>}
+   *
+   * @param addBaggage True if baggage should be added to MDC
+   */
+  public void setAddBaggage(boolean addBaggage) {
+    this.addBaggage = addBaggage;
+  }
 
+  public ILoggingEvent wrapEvent(ILoggingEvent event) {
     Map<String, String> eventContext = event.getMDCPropertyMap();
     if (eventContext != null && eventContext.containsKey(TRACE_ID)) {
       // Assume already instrumented event if traceId is present.
       return event;
     }
 
     Map<String, String> contextData = new HashMap<>();
-    SpanContext spanContext = currentSpan.getSpanContext();
-    contextData.put(TRACE_ID, spanContext.getTraceId());
-    contextData.put(SPAN_ID, spanContext.getSpanId());
-    contextData.put(TRACE_FLAGS, spanContext.getTraceFlags().asHex());
+    Context context = Context.current();
+    Span currentSpan = Span.fromContext(context);
+
+    if (currentSpan.getSpanContext().isValid()) {
+      SpanContext spanContext = currentSpan.getSpanContext();
+      contextData.put(TRACE_ID, spanContext.getTraceId());
+      contextData.put(SPAN_ID, spanContext.getSpanId());
+      contextData.put(TRACE_FLAGS, spanContext.getTraceFlags().asHex());
+    }
+
+    if (addBaggage) {
+      Baggage baggage = Baggage.fromContext(context);
+      baggage.forEach(
+          (key, value) ->
+              contextData.put(
+                  key,
+                  // prefix all baggage values to avoid clashes with existing context
+                  "baggage." + value.getValue()));
+    }
 
     if (eventContext == null) {
       eventContext = contextData;