fix: package logging emitter resource and rename to avoid classpath issues (apache#19359)

The previous fix broadly added src/main/resources as a resource directory,
which inadvertently packaged log4j2.xml, log4j2.debug.xml, and the
services/javax.annotation.processing.Processor file into druid-processing.jar.

The packaged log4j2.xml (console-only) ends up on the classpath of dependent
modules like indexing-service and shadows processing's test log4j2.xml that
contains the RoutingAppender used to route task logs to per-task files. This
caused ThreadingTaskRunnerTest#test_streamTaskLogs_ofRunningTask_readsFromTaskLogFile
to fail because the per-task log file was never written.

Narrow the include to only loggingEmitterAllowedMetrics.json so behavior for
every other file in processing/src/main/resources matches pre-PR state.


Co-authored-by: Sarang Vadali <sarangvadali@salesforce.com>

Author: sarangv

docs/configuration/index.md

@@ -2023,7 +2023,7 @@ log4j config to route these logs to different sources based on the feed of the e
 |`druid.emitter.logging.loggerClass`|The class used for logging.|`org.apache.druid.java.util.emitter.core.LoggingEmitter`|
 |`druid.emitter.logging.logLevel`|Choices: debug, info, warn, error. The log level at which message are logged.|info|
 |`druid.emitter.logging.shouldFilterMetrics`|When true, only metrics listed in the allow list are emitted; non-metric events (e.g. alerts) are always emitted. When false, all events are logged (backward-compatible).|false|
-|`druid.emitter.logging.allowedMetricsPath`|Path to a JSON file whose keys are the allowed metric names. Only used when `shouldFilterMetrics` is true. If null or empty, the bundled classpath resource `defaultMetrics.json` is used. If a path is set but the file is missing, a warning is logged and the emitter falls back to the default classpath resource.|null|
+|`druid.emitter.logging.allowedMetricsPath`|Path to a JSON file whose keys are the allowed metric names. Only used when `shouldFilterMetrics` is true. If null or empty, the bundled classpath resource `loggingEmitterAllowedMetrics.json` is used. If a path is set but the file is missing, a warning is logged and the emitter falls back to the default classpath resource.|null|
 
 #### HTTP emitter module
 

processing/pom.xml

@@ -541,6 +541,12 @@
     </plugins>
 
     <resources>
+      <resource>
+        <directory>src/main/resources</directory>
+        <includes>
+          <include>loggingEmitterAllowedMetrics.json</include>
+        </includes>
+      </resource>
       <resource>
         <directory>
           ${project.build.directory}/hyperic-sigar-${sigar.base.version}/sigar-bin/lib

processing/src/main/java/org/apache/druid/java/util/emitter/core/LoggingEmitter.java

@@ -50,7 +50,7 @@
 public class LoggingEmitter implements Emitter
 {
   private static final Logger LOGGER = new Logger(LoggingEmitter.class);
-  private static final String DEFAULT_ALLOWED_METRICS_RESOURCE = "defaultMetrics.json";
+  private static final String DEFAULT_ALLOWED_METRICS_RESOURCE = "loggingEmitterAllowedMetrics.json";
 
   private final Logger log;
   private final Level level;
@@ -92,9 +92,9 @@ public LoggingEmitter(
 
   /**
    * Loads the allowed metric names from a JSON file. If the path is null or empty,
-   * loads from the bundled classpath resource (defaultMetrics.json). If a custom
-   * path is provided but the file is missing, logs a warning and falls back to
-   * the default classpath resource.
+   * loads from the bundled classpath resource (loggingEmitterAllowedMetrics.json).
+   * If a custom path is provided but the file is missing, logs a warning and falls
+   * back to the default classpath resource.
    */
   private static Set<String> loadAllowedMetrics(@Nullable String path, ObjectMapper jsonMapper)
   {
@@ -112,9 +112,10 @@ private static Set<String> loadAllowedMetrics(@Nullable String path, ObjectMappe
   }
 
   /**
-   * Opens the allowed metrics configuration stream. Uses classpath resource when
-   * path is null/empty. When a custom path is specified but the file is missing,
-   * logs a warning and falls back to the default classpath resource.
+   * Opens the allowed metrics configuration stream. Uses the bundled
+   * loggingEmitterAllowedMetrics.json classpath resource when path is null/empty.
+   * When a custom path is specified but the file is missing, logs a warning and
+   * falls back to the default classpath resource.
    */
   private static InputStream openAllowedMetricsStream(@Nullable String path)
   {

processing/src/main/java/org/apache/druid/java/util/emitter/core/LoggingEmitterConfig.java

@@ -39,8 +39,8 @@ public class LoggingEmitterConfig
   /**
    * When true, only metrics listed in the allowed metrics configuration are emitted.
    * If {@link #allowedMetricsPath} is null/empty, the bundled default allowlist
-   * (defaultMetrics.json on the classpath) is used. If a path is provided,
-   * it is loaded from that file instead.
+   * (loggingEmitterAllowedMetrics.json on the classpath) is used. If a path is
+   * provided, it is loaded from that file instead.
    * Defaults to false (emit all metrics, backward-compatible behavior).
    */
   @JsonProperty("shouldFilterMetrics")
@@ -49,8 +49,8 @@ public class LoggingEmitterConfig
   /**
    * Optional path to a JSON file containing an array of allowed metric names.
    * Only used when {@link #shouldFilterMetrics} is true.
-   * If null or empty, the bundled default resource (defaultMetrics.json) is loaded
-   * from the classpath, mirroring how the Prometheus emitter loads its defaultMetrics.json.
+   * If null or empty, the bundled default resource (loggingEmitterAllowedMetrics.json)
+   * is loaded from the classpath.
    */
   @JsonProperty
   @Nullable

…g/src/main/resources/defaultMetrics.json …ources/loggingEmitterAllowedMetrics.jsonprocessing/src/main/resources/defaultMetrics.json renamed to processing/src/main/resources/loggingEmitterAllowedMetrics.json processing/src/main/resources/defaultMetrics.json renamed to processing/src/main/resources/loggingEmitterAllowedMetrics.json

@@ -107,8 +107,8 @@ public void testEmitAllWhenFilteringDisabled()
 
   /**
    * With filtering enabled and no custom path, the default classpath resource
-   * (defaultMetrics.json) should be loaded. Metrics in the default list
-   * are emitted; unlisted metrics are dropped.
+   * (loggingEmitterAllowedMetrics.json) should be loaded. Metrics in the default
+   * list are emitted; unlisted metrics are dropped.
    */
   @Test
   public void testFilterWithDefaultResource()