add comments for future config enhancement

Author: SylvainJuge

jmx-scraper/build.gradle.kts

@@ -20,10 +20,8 @@ repositories {
   maven {
     setUrl("https://oss.sonatype.org/content/repositories/snapshots")
   }
-
 }
 
-
 dependencies {
   // TODO remove snapshot dependency on upstream once 2.9.0 is released
   api(enforcedPlatform("io.opentelemetry.instrumentation:opentelemetry-instrumentation-bom-alpha:2.9.0-alpha-SNAPSHOT"))

jmx-scraper/src/main/java/io/opentelemetry/contrib/jmxscraper/JmxScraper.java

@@ -46,6 +46,7 @@ public class JmxScraper {
   public static void main(String[] args) {
 
     // enable SDK auto-configure if not explicitly set by user
+    // TODO: refactor this to use AutoConfiguredOpenTelemetrySdk
     if (System.getProperty(OTEL_AUTOCONFIGURE) == null) {
       System.setProperty(OTEL_AUTOCONFIGURE, "true");
     }
@@ -57,10 +58,11 @@ public static void main(String[] args) {
       // this also enables SDK auto-configuration to use those properties
       config.propagateSystemProperties();
 
-      JmxMetricInsight service = JmxMetricInsight.createService(GlobalOpenTelemetry.get(),
-          config.getIntervalMilliseconds());
-      JmxScraper jmxScraper = new JmxScraper(JmxConnectorBuilder.createNew(config.getServiceUrl()),
-          service, config);
+      JmxMetricInsight service =
+          JmxMetricInsight.createService(
+              GlobalOpenTelemetry.get(), config.getIntervalMilliseconds());
+      JmxScraper jmxScraper =
+          new JmxScraper(JmxConnectorBuilder.createNew(config.getServiceUrl()), service, config);
       jmxScraper.start();
 
     } catch (ArgumentsParsingException e) {
@@ -133,10 +135,13 @@ private static Properties loadPropertiesFromPath(String path) throws Configurati
   }
 
   private void start() throws IOException {
-    Runtime.getRuntime().addShutdownHook(new Thread(() -> {
-      logger.info("JMX scraping stopped");
-      running.set(false);
-    }));
+    Runtime.getRuntime()
+        .addShutdownHook(
+            new Thread(
+                () -> {
+                  logger.info("JMX scraping stopped");
+                  running.set(false);
+                }));
 
     try (JMXConnector connector = client.build()) {
       MBeanServerConnection connection = connector.getMBeanServerConnection();
@@ -183,6 +188,4 @@ private static void addRulesForSystem(String system, MetricConfiguration conf) {
       throw new IllegalStateException("error while loading rules for system " + system, e);
     }
   }
-
-
 }

jmx-scraper/src/main/java/io/opentelemetry/contrib/jmxscraper/config/JmxScraperConfig.java

@@ -55,9 +55,9 @@ public class JmxScraperConfig {
   private String serviceUrl = "";
   private String customJmxScrapingConfigPath = "";
   private Set<String> targetSystems = Collections.emptySet();
-  private int intervalMilliseconds;
-  private String metricsExporterType = "";
-  private String otlpExporterEndpoint = "";
+  private int intervalMilliseconds; // TODO only used to set 'otel.metric.export.interval' from SDK
+  private String metricsExporterType = ""; // TODO only used to default to 'logging' if not set
+  private String otlpExporterEndpoint = ""; // TODO not really needed here as handled by SDK
   private String username = "";
   private String password = "";
   private String realm = "";