HZ-8: Preserve Hazelcast settings between plugin upgrades

src/plugins/hazelcast/classes/hazelcast-cache-config.xml

@@ -18,10 +18,7 @@
            xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
            xsi:schemaLocation="http://www.hazelcast.com/schema/config
            http://www.hazelcast.com/schema/config/hazelcast-config-3.9.xsd">
-    <group>
-        <name>openfire</name>
-        <password>openfire</password>
-    </group>
+    <import resource="${openfireHome}/conf/hazelcast-local-config.xml"/>
     <properties>
       <property name="hazelcast.logging.type">slf4j</property>
       <property name="hazelcast.operation.call.timeout.millis">30000</property>
@@ -29,42 +26,6 @@
       <property name="hazelcast.rest.enabled">false</property>
     </properties>
     <management-center enabled="false"/>
-    <network>
-        <port auto-increment="true" port-count="100">5701</port>
-        <outbound-ports>
-            <ports>0</ports>
-        </outbound-ports>
-        <join>
-            <multicast enabled="true">
-                <multicast-group>224.2.2.3</multicast-group>
-                <multicast-port>54327</multicast-port>
-            </multicast>
-            <tcp-ip enabled="false"/>
-            <aws enabled="false"/>
-        </join>
-        <interfaces enabled="false">
-            <interface>10.10.1.*</interface>
-        </interfaces>
-        <ssl enabled="false"/>
-        <socket-interceptor enabled="false"/>
-        <symmetric-encryption enabled="false">
-            <!--
-               encryption algorithm such as
-               DES/ECB/PKCS5Padding,
-               PBEWithMD5AndDES,
-               AES/CBC/PKCS5Padding,
-               Blowfish,
-               DESede
-            -->
-            <algorithm>PBEWithMD5AndDES</algorithm>
-            <!-- salt value to use when generating the secret key -->
-            <salt>thesalt</salt>
-            <!-- pass phrase to use when generating the secret key -->
-            <password>thepass</password>
-            <!-- iteration count to use when generating the secret key -->
-            <iteration-count>19</iteration-count>
-        </symmetric-encryption>
-    </network>
     <partition-group enabled="false"/>
     <executor-service name="default">
         <pool-size>16</pool-size>

src/plugins/hazelcast/classes/hazelcast-local-config.xml.template

+<?xml version="1.0" encoding="UTF-8"?>
+<hazelcast xmlns="http://www.hazelcast.com/schema/config"
+           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+           xsi:schemaLocation="http://www.hazelcast.com/schema/config
+           http://www.hazelcast.com/schema/config/hazelcast-config-3.9.xsd">
+    <group>
+        <name>openfire</name>
+        <password>openfire</password>
+    </group>
+    <network>
+        <port auto-increment="true" port-count="100">5701</port>
+        <outbound-ports>
+            <ports>0</ports>
+        </outbound-ports>
+        <!-- The following enables multicast discovery of cluster members
+                See http://docs.hazelcast.org/docs/3.9.2/manual/html-single/index.html#discovering-members-by-multicast
+        -->
+        <join>
+            <multicast enabled="true">
+                <multicast-group>224.2.2.3</multicast-group>
+                <multicast-port>54327</multicast-port>
+            </multicast>
+            <tcp-ip enabled="false"/>
+        </join>
+        <!-- The following enables TCP/IP based discovery of cluster members
+                See http://docs.hazelcast.org/docs/3.9.2/manual/html-single/index.html#discovering-members-by-tcp
+        -->
+        <!--
+        <join>
+            <multicast enabled="false"/>
+            <tcp-ip enabled="true">
+                <member>10.10.1.1:5701</member>
+				<member>10.10.1.2:5701</member>
+            </tcp-ip>
+        </join>
+        -->
+        <interfaces enabled="false">
+            <interface>10.10.1.*</interface>
+        </interfaces>
+        <ssl enabled="false"/>
+        <socket-interceptor enabled="false"/>
+        <symmetric-encryption enabled="false">
+            <!--
+               encryption algorithm such as
+               DES/ECB/PKCS5Padding,
+               PBEWithMD5AndDES,
+               AES/CBC/PKCS5Padding,
+               Blowfish,
+               DESede
+            -->
+            <algorithm>PBEWithMD5AndDES</algorithm>
+            <!-- salt value to use when generating the secret key -->
+            <salt>thesalt</salt>
+            <!-- pass phrase to use when generating the secret key -->
+            <password>thepass</password>
+            <!-- iteration count to use when generating the secret key -->
+            <iteration-count>19</iteration-count>
+        </symmetric-encryption>
+    </network>
+</hazelcast>

src/plugins/hazelcast/src/java/org/jivesoftware/openfire/plugin/HazelcastPlugin.java

@@ -16,9 +16,6 @@
 
 package org.jivesoftware.openfire.plugin;
 
-import java.io.File;
-import java.io.FileFilter;
-
 import org.jivesoftware.openfire.XMPPServer;
 import org.jivesoftware.openfire.cluster.ClusterManager;
 import org.jivesoftware.openfire.container.Plugin;
@@ -28,6 +25,13 @@ import org.jivesoftware.util.JiveGlobals;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.io.File;
+import java.io.FileFilter;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
 /**
  * Hazelcast clustering plugin. This implementation is based upon
  * (and borrows heavily from) the original Openfire clustering plugin.
@@ -38,38 +42,51 @@ import org.slf4j.LoggerFactory;
  */
 public class HazelcastPlugin implements Plugin {
 
-    private static Logger logger = LoggerFactory.getLogger(HazelcastPlugin.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(HazelcastPlugin.class);
 
+    @Override
     public void initializePlugin(final PluginManager manager, final File pluginDirectory) {
-        logger.info("Waiting for other plugins to initialize before initializing clustering");
+        LOGGER.info("Waiting for other plugins to initialize before initializing clustering");
         manager.addPluginManagerListener(new PluginManagerListener() {
             @Override
             public void pluginsMonitored() {
                 manager.removePluginManagerListener(this);
-                initializeClustering();
+                initializeClustering(pluginDirectory);
             }
         });
     }
 
-    private void initializeClustering() {
-        logger.info("All plugins have initialized; initializing clustering");
+    private void initializeClustering(final File hazelcastPluginDirectory) {
+        LOGGER.info("All plugins have initialized; initializing clustering");
         // Check if another cluster is installed and stop loading this plugin if found
-        File pluginDir = new File(JiveGlobals.getHomeDirectory(), "plugins");
+        final String openfireHome = JiveGlobals.getHomeDirectory();
+        File pluginDir = new File(openfireHome, "plugins");
         File[] jars = pluginDir.listFiles(new FileFilter() {
+            @Override
             public boolean accept(File pathname) {
                 String fileName = pathname.getName().toLowerCase();
                 return (fileName.equalsIgnoreCase("enterprise.jar") || 
                         fileName.equalsIgnoreCase("coherence.jar"));
             }
         });
-        if (jars.length > 0) {
+        if (jars != null && jars.length > 0) {
             // Do not load this plugin if a conflicting implementation exists
-            logger.warn("Conflicting clustering plugins found; remove Coherence and/or Enterprise jar files");
-            throw new IllegalStateException("Clustering plugin configuration conflict (Coherence)");
+            LOGGER.warn("Conflicting clustering plugins found; remove Coherence and/or Enterprise jar files");
+            return;
+        }
+
+        try {
+            final Path pathToLocalHazelcastConfig = Paths.get(openfireHome, "conf/hazelcast-local-config.xml");
+            if (!Files.exists(pathToLocalHazelcastConfig)) {
+                Files.copy(Paths.get(hazelcastPluginDirectory.getAbsolutePath(), "classes/hazelcast-local-config.xml.template"), pathToLocalHazelcastConfig);
             }
             ClusterManager.startup();
+        } catch (final IOException e) {
+            LOGGER.warn("Unable to create local Hazelcast configuration file from template; clustering will not start", e);
+        }
     }
 
+    @Override
     public void destroyPlugin() {
         // Shutdown is initiated by XMPPServer before unloading plugins
         if (!XMPPServer.getInstance().isShuttingDown()) {