Add excluding Logback MDC attributes

This change adds a setting to the Logback appender to exclude MDC attributes when all attributes are being copied.

Author: cfredri4

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

@@ -5,8 +5,6 @@
 
 package io.opentelemetry.instrumentation.logback.appender.v1_0;
 
-import static java.util.Collections.emptyList;
-
 import ch.qos.logback.classic.LoggerContext;
 import ch.qos.logback.classic.spi.ILoggingEvent;
 import ch.qos.logback.core.Appender;
@@ -37,7 +35,8 @@ public class OpenTelemetryAppender extends UnsynchronizedAppenderBase<ILoggingEv
   private boolean captureLoggerContext = false;
   private boolean captureArguments = false;
   private boolean captureLogstashAttributes = false;
-  private List<String> captureMdcAttributes = emptyList();
+  private List<String> captureMdcAttributes = List.of();
+  private Set<String> excludeMdcAttributes = Set.of();
   private boolean captureEventName = false;
 
   private volatile OpenTelemetry openTelemetry;
@@ -83,6 +82,7 @@ public void start() {
         LoggingEventMapper.builder()
             .setCaptureExperimentalAttributes(captureExperimentalAttributes)
             .setCaptureMdcAttributes(captureMdcAttributes)
+            .setExcludeMdcAttributes(excludeMdcAttributes)
             .setCaptureCodeAttributes(captureCodeAttributes)
             .setCaptureMarkerAttribute(captureMarkerAttribute)
             .setCaptureKeyValuePairAttributes(captureKeyValuePairAttributes)
@@ -193,12 +193,31 @@ public void setCaptureLogstashAttributes(boolean captureLogstashAttributes) {
     this.captureLogstashAttributes = captureLogstashAttributes;
   }
 
-  /** Configures the {@link MDC} attributes that will be copied to logs. */
+  /**
+   * Configures the {@link MDC} attributes that will be copied to logs. A single wildcard * will
+   * copy all attributes.
+   *
+   * @param attributes The attributes to copy
+   */
   public void setCaptureMdcAttributes(String attributes) {
     if (attributes != null) {
       captureMdcAttributes = filterBlanksAndNulls(attributes.split(","));
     } else {
-      captureMdcAttributes = emptyList();
+      captureMdcAttributes = List.of();
+    }
+  }
+
+  /**
+   * Configures the {@link MDC} attributes that will be excluded from being copied to logs when
+   * all attributes are being copied.
+   *
+   * @param attributes The attributes to exclude from being copied
+   */
+  public void setExcludeMdcAttributes(String attributes) {
+    if (attributes != null) {
+      excludeMdcAttributes = Set.copyOf(filterBlanksAndNulls(attributes.split(",")));
+    } else {
+      excludeMdcAttributes = Set.of();
     }
   }
 

instrumentation/logback/logback-appender-1.0/library/src/main/java/io/opentelemetry/instrumentation/logback/appender/v1_0/internal/LoggingEventMapper.java

@@ -8,7 +8,6 @@
 import static io.opentelemetry.semconv.CodeAttributes.CODE_FILE_PATH;
 import static io.opentelemetry.semconv.CodeAttributes.CODE_FUNCTION_NAME;
 import static io.opentelemetry.semconv.CodeAttributes.CODE_LINE_NUMBER;
-import static java.util.Collections.emptyList;
 
 import ch.qos.logback.classic.Level;
 import ch.qos.logback.classic.spi.ILoggingEvent;
@@ -35,6 +34,7 @@
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 import java.util.concurrent.TimeUnit;
 import java.util.function.Function;
 import java.util.stream.Collectors;
@@ -77,6 +77,7 @@ public final class LoggingEventMapper {
 
   private final boolean captureExperimentalAttributes;
   private final List<String> captureMdcAttributes;
+  private final Set<String> excludeMdcAttributes;
   private final boolean captureAllMdcAttributes;
   private final boolean captureCodeAttributes;
   private final boolean captureMarkerAttribute;
@@ -90,6 +91,7 @@ private LoggingEventMapper(Builder builder) {
     this.captureExperimentalAttributes = builder.captureExperimentalAttributes;
     this.captureCodeAttributes = builder.captureCodeAttributes;
     this.captureMdcAttributes = builder.captureMdcAttributes;
+    this.excludeMdcAttributes = builder.excludeMdcAttributes;
     this.captureMarkerAttribute = builder.captureMarkerAttribute;
     this.captureKeyValuePairAttributes = builder.captureKeyValuePairAttributes;
     this.captureLoggerContext = builder.captureLoggerContext;
@@ -243,7 +245,9 @@ private static void setTimestampFromInstant(
   void captureMdcAttributes(LogRecordBuilder builder, Map<String, String> mdcProperties) {
     if (captureAllMdcAttributes) {
       for (Map.Entry<String, String> entry : mdcProperties.entrySet()) {
-        setAttributeOrEventName(builder, getAttributeKey(entry.getKey()), entry.getValue());
+        if (!excludeMdcAttributes.contains(entry.getKey())) {
+          setAttributeOrEventName(builder, getAttributeKey(entry.getKey()), entry.getValue());
+        }
       }
       return;
     }
@@ -636,7 +640,8 @@ protected FieldReader computeValue(Class<?> type) {
    */
   public static final class Builder {
     private boolean captureExperimentalAttributes;
-    private List<String> captureMdcAttributes = emptyList();
+    private List<String> captureMdcAttributes = List.of();
+    private Set<String> excludeMdcAttributes = Set.of();
     private boolean captureCodeAttributes;
     private boolean captureMarkerAttribute;
     private boolean captureKeyValuePairAttributes;
@@ -659,6 +664,12 @@ public Builder setCaptureMdcAttributes(List<String> captureMdcAttributes) {
       return this;
     }
 
+    @CanIgnoreReturnValue
+    public Builder setExcludeMdcAttributes(Set<String> excludeMdcAttributes) {
+      this.excludeMdcAttributes = excludeMdcAttributes;
+      return this;
+    }
+
     @CanIgnoreReturnValue
     public Builder setCaptureCodeAttributes(boolean captureCodeAttributes) {
       this.captureCodeAttributes = captureCodeAttributes;