Provide extensibility mechanism where additional subreports can be added

pom.xml

@@ -5,7 +5,7 @@
 
   <groupId>com.redhat.insights</groupId>
   <artifactId>runtimes-agent</artifactId>
-  <version>1.0.4</version>
+  <version>1.0.5-SNAPSHOT</version>
 
   <name>Red Hat Insights Java Agent</name>
   <description>Red Hat Insights Java Agent</description>

src/main/java/com/redhat/insights/agent/AgentBasicReport.java

@@ -1,13 +1,15 @@
-/* Copyright (C) Red Hat 2023-2024 */
+/* Copyright (C) Red Hat 2023-2025 */
 package com.redhat.insights.agent;
 
+import com.redhat.insights.agent.api.SubreportProvider;
 import com.redhat.insights.config.InsightsConfiguration;
 import com.redhat.insights.jars.ClasspathJarInfoSubreport;
 import com.redhat.insights.logging.InsightsLogger;
 import com.redhat.insights.reports.AbstractTopLevelReportBase;
 import com.redhat.insights.reports.InsightsSubreport;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.ServiceLoader;
 
 public class AgentBasicReport extends AbstractTopLevelReportBase {
   private static final InsightsLogger logger = AgentLogger.getLogger();
@@ -22,9 +24,34 @@ public static AgentBasicReport of(AgentConfiguration configuration) {
     ClasspathJarInfoSubreport jarsReport = new ClasspathJarInfoSubreport(logger);
     reports.put("jars", jarsReport);
     reports.put("details", AgentSubreport.of(jarsReport, configuration));
+    addExtensionReports(reports, configuration);
     return new AgentBasicReport(configuration, reports);
   }
 
+  private static void addExtensionReports(
+      Map<String, InsightsSubreport> reports, AgentConfiguration configuration) {
+    // Load the agent SubreportProvider if available
+    ServiceLoader<SubreportProvider> loader = ServiceLoader.load(SubreportProvider.class);
+    for (SubreportProvider provider : loader) {
+      Map<String, InsightsSubreport> subs = provider.provideSubreports(configuration, logger);
+      // add any provided subreports to main agent report
+      // ensure there is no name conflict, fail if there is
+      for (String name : subs.keySet()) {
+        if (reports.containsKey(name)) {
+          throw new RuntimeException(
+              "The key provided by the subreport provider ('"
+                  + name
+                  + "': "
+                  + subs.get(name)
+                  + ") exists already! ("
+                  + reports.get(name)
+                  + ")");
+        }
+        reports.put(name, subs.get(name));
+      }
+    }
+  }
+
   @Override
   protected long getProcessPID() {
     return Long.parseLong(

src/main/java/com/redhat/insights/agent/AgentMain.java

@@ -31,6 +31,16 @@ private AgentMain(AgentConfiguration configuration, BlockingQueue<JarInfo> jarsT
 
   public static void premain(String agentArgs, Instrumentation instrumentation) {
     startAgent(agentArgs, instrumentation);
+
+    // There seems to be some kind of race condition between premain() and java main class main()
+    //   which results in JVM intermittently exiting with status 1 after return from premain() and
+    //   before invoking main class main()
+    // Observed on macOS with OpenJDK 17 using -shaded.jar
+    // The next lines make the problem go away
+    try {
+      Thread.sleep(1);
+    } catch (InterruptedException e) {
+    }
   }
 
   public static void agentmain(String agentArgs, Instrumentation instrumentation) {

src/main/java/com/redhat/insights/agent/api/SubreportProvider.java

@@ -0,0 +1,13 @@
+/* Copyright (C) Red Hat 2025 */
+package com.redhat.insights.agent.api;
+
+import com.redhat.insights.agent.AgentConfiguration;
+import com.redhat.insights.logging.InsightsLogger;
+import com.redhat.insights.reports.InsightsSubreport;
+import java.util.Map;
+
+public interface SubreportProvider {
+
+  Map<String, InsightsSubreport> provideSubreports(
+      AgentConfiguration configuration, InsightsLogger logger);
+}