Added createComponent to Extension interface

build.gradle

@@ -51,8 +51,7 @@ publishing {
 
 repositories {
     mavenLocal()
-    // Remove the commented code below once TransportService is published to maven
-    //maven { url "https://aws.oss.sonatype.org/content/repositories/snapshots" }
+    maven { url "https://aws.oss.sonatype.org/content/repositories/snapshots" }
     maven { url "https://d1nvenhzbhpy0q.cloudfront.net/snapshots/lucene/"}
     mavenCentral()
 }
@@ -69,6 +68,7 @@ dependencies {
     implementation 'org.opensearch.client:opensearch-rest-client:2.0.0'
     implementation 'org.opensearch.client:opensearch-java:2.0.0'
     implementation "io.netty:netty-all:4.1.73.Final"
+    implementation "org.apache.lucene:lucene-core:9.4.0-snapshot-ddf0d0a"
     testCompileOnly ("junit:junit:4.13.2") {
         exclude module : 'hamcrest'
         exclude module : 'hamcrest-core'

src/main/java/org/opensearch/sdk/BaseExtension.java

@@ -0,0 +1,57 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+package org.opensearch.sdk;
+
+import java.util.Collection;
+import java.util.Collections;
+
+import org.opensearch.cluster.service.ClusterService;
+import org.opensearch.threadpool.ThreadPool;
+
+/**
+ * An abstract class that provides sample methods required by extensions
+ */
+public abstract class BaseExtension implements Extension {
+    /**
+     * A client to make requests to the system
+     */
+    protected SDKClient client;
+
+    /**
+     * A service to allow watching and updating cluster state
+     */
+    protected ClusterService clusterService;
+
+    /**
+     * A service to allow retrieving an executor to run an async action
+     */
+    protected ThreadPool threadPool;
+
+    /**
+     * Empty constructor to fulfill abstract class requirements
+     */
+    protected BaseExtension() {
+
+    }
+
+    /**
+     * Returns components added by this extension.
+     *
+     * @param client A client to make requests to the system
+     * @param clusterService A service to allow watching and updating cluster state
+     * @param threadPool A service to allow retrieving an executor to run an async action
+     * @return A collection of objects
+     */
+    public Collection<Object> createComponents(SDKClient client, ClusterService clusterService, ThreadPool threadPool) {
+        this.client = client;
+        this.clusterService = clusterService;
+        this.threadPool = threadPool;
+
+        return Collections.emptyList();
+    }
+}

src/main/java/org/opensearch/sdk/Extension.java

@@ -11,9 +11,13 @@
 import java.io.IOException;
 import java.net.URL;
 import java.util.Collections;
+import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 
+import org.opensearch.cluster.service.ClusterService;
+import org.opensearch.threadpool.ThreadPool;
+
 import org.opensearch.action.ActionRequest;
 import org.opensearch.action.ActionResponse;
 import org.opensearch.action.support.TransportAction;
@@ -52,6 +56,16 @@ default List<Setting<?>> getSettings() {
         return Collections.emptyList();
     }
 
+    /**
+     * Returns components added by this extension.
+     *
+     * @param client A client to make requests to the system
+     * @param clusterService A service to allow watching and updating cluster state
+     * @param threadPool A service to allow retrieving an executor to run an async action
+     * @return A collection of objects
+     */
+    public Collection<Object> createComponents(SDKClient client, ClusterService clusterService, ThreadPool threadPool);
+
     /**
      * Gets an optional list of custom {@link TransportAction} for the extension to register with OpenSearch.
      *

src/main/java/org/opensearch/sdk/ExtensionsRunner.java

@@ -93,6 +93,7 @@ public class ExtensionsRunner {
         new ExtensionsIndicesModuleNameRequestHandler();
     private ExtensionsRestRequestHandler extensionsRestRequestHandler = new ExtensionsRestRequestHandler(extensionRestPathRegistry);
     private NettyTransport nettyTransport = new NettyTransport();
+    private SDKClient client = new SDKClient();
 
     /*
      * TODO: expose an interface for extension to register actions
@@ -132,7 +133,10 @@ protected ExtensionsRunner(Extension extension) throws IOException {
         // save custom transport actions
         this.transportActions = new TransportActions(extension.getActions());
         // initialize the transport service
-        nettyTransport.initializeExtensionTransportService(this.getSettings(), this);
+        ThreadPool threadPool = new ThreadPool(this.getSettings());
+        nettyTransport.initializeExtensionTransportService(this.getSettings(), threadPool, this);
+        // create components
+        extension.createComponents(client, null, threadPool);
     }
 
     /**

src/main/java/org/opensearch/sdk/NettyTransport.java

@@ -85,12 +85,15 @@ public Netty4Transport getNetty4Transport(Settings settings, ThreadPool threadPo
      * Initializes the TransportService object for this extension. This object will control communication between the extension and OpenSearch.
      *
      * @param settings  The transport settings to configure.
+     * @param threadPool The thread pool to use to start transport service.
      * @param extensionsRunner method to call
      * @return The initialized TransportService object.
      */
-    public TransportService initializeExtensionTransportService(Settings settings, ExtensionsRunner extensionsRunner) {
-
-        ThreadPool threadPool = new ThreadPool(settings);
+    public TransportService initializeExtensionTransportService(
+        Settings settings,
+        ThreadPool threadPool,
+        ExtensionsRunner extensionsRunner
+    ) {
 
         Netty4Transport transport = getNetty4Transport(settings, threadPool);
 

src/main/java/org/opensearch/sdk/sample/helloworld/HelloWorldExtension.java

@@ -10,6 +10,7 @@
 import java.io.IOException;
 import java.util.List;
 
+import org.opensearch.sdk.BaseExtension;
 import org.opensearch.sdk.Extension;
 import org.opensearch.sdk.ExtensionRestHandler;
 import org.opensearch.sdk.ExtensionSettings;
@@ -25,7 +26,7 @@
  * <p>
  * To execute, pass an instatiated object of this class to {@link ExtensionsRunner#run(Extension)}.
  */
-public class HelloWorldExtension implements Extension {
+public class HelloWorldExtension extends BaseExtension {
 
     /**
      * Optional classpath-relative path to a yml file containing extension settings.
@@ -41,6 +42,7 @@ public class HelloWorldExtension implements Extension {
      * Instantiate this extension, initializing the connection settings and REST actions.
      */
     public HelloWorldExtension() {
+        super();
         try {
             this.settings = initializeSettings();
         } catch (IOException e) {

src/test/java/org/opensearch/sdk/ExtensionsRunnerForTest.java

@@ -15,7 +15,7 @@ public class ExtensionsRunnerForTest extends ExtensionsRunner {
      * @throws IOException if the runner failed to read settings or API.
      */
     public ExtensionsRunnerForTest() throws IOException {
-        super(new Extension() {
+        super(new BaseExtension() {
             @Override
             public ExtensionSettings getExtensionSettings() {
                 return new ExtensionSettings("sample-extension", "127.0.0.1", "4532");

src/test/java/org/opensearch/sdk/TransportCommunicationIT.java

@@ -147,7 +147,8 @@ private void startTransportandClient(Settings settings, Thread client) throws IO
         // retrieve transport service
         ExtensionsRunner extensionsRunner = new ExtensionsRunnerForTest();
         // start transport service
-        TransportService transportService = nettyTransport.initializeExtensionTransportService(settings, extensionsRunner);
+        ThreadPool threadPool = new ThreadPool(settings);
+        TransportService transportService = nettyTransport.initializeExtensionTransportService(settings, threadPool, extensionsRunner);
 
         assertEquals(Lifecycle.State.STARTED, transportService.lifecycleState());