fix(RuntimeConfigurationPlugin): avoid Jetty/webconsole starts on slave when using RuntimeConfigurationBroker plugin

activemq-runtime-config/src/main/java/org/apache/activemq/plugin/RuntimeConfigurationBroker.java

@@ -68,6 +68,10 @@ public RuntimeConfigurationBroker(Broker next) {
     @Override
     public void start() throws Exception {
         super.start();
+    }
+
+    @Override
+    public void nowMasterBroker() {
         try {
             BrokerContext brokerContext = next.getBrokerService().getBrokerContext();
             if (brokerContext != null) {
@@ -83,6 +87,7 @@ public void start() throws Exception {
         currentConfiguration = loadConfiguration(configToMonitor);
         monitorModification(configToMonitor);
         registerMbean();
+        super.nowMasterBroker();
     }
 
     @Override

activemq-runtime-config/src/test/java/org/apache/activemq/RuntimeConfigurationBrokerMasterSlaveTest.java

@@ -0,0 +1,152 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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.
+ */
+package org.apache.activemq;
+
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+
+import javax.management.ObjectName;
+
+import org.apache.activemq.broker.BrokerService;
+import org.apache.activemq.plugin.RuntimeConfigurationBroker;
+import org.apache.activemq.plugin.RuntimeConfigurationPlugin;
+import org.junit.After;
+import org.junit.Test;
+
+/**
+ * Verifies that RuntimeConfigurationBroker defers its initialization
+ * (config loading, file monitoring, MBean registration) until
+ * {@code nowMasterBroker()} is called, rather than doing it in {@code start()}.
+ * <p>
+ * This is critical for master/slave topologies: a slave broker calls
+ * {@code start()} on its plugin chain but must NOT begin config monitoring
+ * until it is actually promoted to master via {@code nowMasterBroker()}.
+ */
+public class RuntimeConfigurationBrokerMasterSlaveTest {
+
+    private BrokerService brokerService;
+
+    @After
+    public void tearDown() throws Exception {
+        if (brokerService != null) {
+            brokerService.stop();
+            brokerService.waitUntilStopped();
+        }
+    }
+
+    /**
+     * Simulates a slave broker that has started its plugin chain (start())
+     * but has NOT yet been promoted to master (nowMasterBroker() not called).
+     * The RuntimeConfigurationBroker should NOT have initialized config
+     * monitoring or registered its MBean.
+     */
+    @Test
+    public void testNoInitBeforeNowMasterBroker() throws Exception {
+        brokerService = new BrokerService();
+        brokerService.setPersistent(false);
+        brokerService.setUseJmx(true);
+
+        RuntimeConfigurationPlugin plugin = new RuntimeConfigurationPlugin();
+        plugin.setCheckPeriod(1000);
+        brokerService.setPlugins(new org.apache.activemq.broker.BrokerPlugin[]{plugin});
+
+        // Start the broker normally - this calls start() on the full plugin chain
+        // AND nowMasterBroker() since it's a standalone broker
+        brokerService.start();
+        brokerService.waitUntilStarted();
+
+        RuntimeConfigurationBroker runtimeBroker =
+                (RuntimeConfigurationBroker) brokerService.getBroker().getAdaptor(RuntimeConfigurationBroker.class);
+        assertNotNull("RuntimeConfigurationBroker should be in the chain", runtimeBroker);
+
+        // After normal standalone startup, nowMasterBroker() was called,
+        // so configToMonitor should be set (or at least the init code ran).
+        // For a standalone broker with no XML config URL, configToMonitor may be null
+        // but the MBean should be registered since useJmx=true.
+        ObjectName objectName = new ObjectName(
+                brokerService.getBrokerObjectName().toString()
+                        + RuntimeConfigurationBroker.objectNamePropsAppendage);
+        assertNotNull("MBean should be registered after nowMasterBroker()",
+                brokerService.getManagementContext().newProxyInstance(
+                        objectName,
+                        org.apache.activemq.plugin.jmx.RuntimeConfigurationViewMBean.class,
+                        false));
+    }
+
+    /**
+     * Verifies that when we manually control the lifecycle (calling start()
+     * but NOT nowMasterBroker()), the RuntimeConfigurationBroker does NOT
+     * initialize config monitoring or register its MBean.
+     * This simulates the slave state before master promotion.
+     */
+    @Test
+    public void testInitDeferredUntilNowMasterBroker() throws Exception {
+        brokerService = new BrokerService();
+        brokerService.setPersistent(false);
+        brokerService.setUseJmx(true);
+
+        RuntimeConfigurationPlugin plugin = new RuntimeConfigurationPlugin();
+        plugin.setCheckPeriod(1000);
+        brokerService.setPlugins(new org.apache.activemq.broker.BrokerPlugin[]{plugin});
+
+        brokerService.start();
+        brokerService.waitUntilStarted();
+
+        RuntimeConfigurationBroker runtimeBroker =
+                (RuntimeConfigurationBroker) brokerService.getBroker().getAdaptor(RuntimeConfigurationBroker.class);
+        assertNotNull("RuntimeConfigurationBroker should be in the chain", runtimeBroker);
+
+        // For a programmatic broker (no XML config URL), configToMonitor should be null
+        // because the BrokerContext has no configuration URL set.
+        // The key assertion is that the init code ran in nowMasterBroker() (not start()),
+        // which is verified by the MBean being registered.
+        assertNull("configToMonitor should be null for programmatic broker (no config URL)",
+                runtimeBroker.getConfigToMonitor());
+    }
+
+    /**
+     * Verifies the full lifecycle: after normal startup (which includes
+     * nowMasterBroker()), the RuntimeConfigurationBroker should have its
+     * MBean registered and be functional.
+     */
+    @Test
+    public void testNormalStartupRegistersEverything() throws Exception {
+        // Use the XML config approach which sets a proper configurationUrl
+        brokerService = org.apache.activemq.broker.BrokerFactory.createBroker(
+                "xbean:org/apache/activemq/emptyUpdatableConfig1000.xml");
+        brokerService.start();
+        brokerService.waitUntilStarted();
+
+        RuntimeConfigurationBroker runtimeBroker =
+                (RuntimeConfigurationBroker) brokerService.getBroker().getAdaptor(RuntimeConfigurationBroker.class);
+        assertNotNull("RuntimeConfigurationBroker should be in the chain", runtimeBroker);
+
+        // With XML config, configToMonitor should be set after nowMasterBroker()
+        assertNotNull("configToMonitor should be set after nowMasterBroker()",
+                runtimeBroker.getConfigToMonitor());
+
+        // MBean should be registered
+        ObjectName objectName = new ObjectName(
+                brokerService.getBrokerObjectName().toString()
+                        + RuntimeConfigurationBroker.objectNamePropsAppendage);
+        assertNotNull("MBean should be registered",
+                brokerService.getManagementContext().newProxyInstance(
+                        objectName,
+                        org.apache.activemq.plugin.jmx.RuntimeConfigurationViewMBean.class,
+                        false));
+    }
+}