[Backport 1.x] Create SDKRestClient wrapper class around RestHighLevelClient

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

@@ -27,9 +27,36 @@
 import org.apache.hc.core5.http.nio.ssl.TlsStrategy;
 import org.apache.hc.core5.reactor.ssl.TlsDetails;
 import org.apache.hc.core5.ssl.SSLContextBuilder;
+import org.opensearch.action.ActionListener;
+import org.opensearch.action.admin.indices.alias.get.GetAliasesRequest;
+import org.opensearch.action.admin.indices.delete.DeleteIndexRequest;
+import org.opensearch.action.delete.DeleteRequest;
+import org.opensearch.action.delete.DeleteResponse;
+import org.opensearch.action.get.GetRequest;
+import org.opensearch.action.get.GetResponse;
+import org.opensearch.action.index.IndexRequest;
+import org.opensearch.action.index.IndexResponse;
+import org.opensearch.action.search.SearchRequest;
+import org.opensearch.action.search.SearchResponse;
+import org.opensearch.action.support.master.AcknowledgedResponse;
+import org.opensearch.client.Cancellable;
+import org.opensearch.client.Client;
+import org.opensearch.client.ClusterAdminClient;
+import org.opensearch.client.ClusterClient;
+import org.opensearch.client.GetAliasesResponse;
+import org.opensearch.client.IndicesClient;
+import org.opensearch.client.RequestOptions;
+import org.opensearch.client.Requests;
 import org.opensearch.client.RestClient;
 import org.opensearch.client.RestClientBuilder;
 import org.opensearch.client.RestHighLevelClient;
+import org.opensearch.client.indices.CreateIndexRequest;
+import org.opensearch.client.indices.CreateIndexResponse;
+import org.opensearch.client.indices.GetMappingsRequest;
+import org.opensearch.client.indices.GetMappingsResponse;
+import org.opensearch.client.indices.PutMappingRequest;
+import org.opensearch.client.indices.rollover.RolloverRequest;
+import org.opensearch.client.indices.rollover.RolloverResponse;
 import org.opensearch.client.json.jackson.JacksonJsonpMapper;
 import org.opensearch.client.opensearch.OpenSearchClient;
 import org.opensearch.client.transport.OpenSearchTransport;
@@ -43,16 +70,24 @@
 public class SDKClient implements Closeable {
     private OpenSearchClient javaClient;
     private RestClient restClient;
-    private RestHighLevelClient highLevelClient;
+    private RestHighLevelClient sdkRestClient;
 
-    private RestClientBuilder builder(String hostAddress, int port) {
+    /**
+     * Create and configure a RestClientBuilder
+     *
+     * @param hostAddress The address the client should connect to
+     * @param port The port the client should connect to
+     * @return An instance of the builder
+     */
+    private static RestClientBuilder builder(String hostAddress, int port) {
         RestClientBuilder builder = RestClient.builder(new HttpHost(hostAddress, port));
         builder.setStrictDeprecationMode(true);
         builder.setHttpClientConfigCallback(httpClientBuilder -> {
             try {
                 final TlsStrategy tlsStrategy = ClientTlsStrategyBuilder.create()
                     .setSslContext(SSLContextBuilder.create().loadTrustMaterial(null, (chains, authType) -> true).build())
-                    // disable the certificate since our cluster currently just uses the default security configuration
+                    // disable the certificate since our cluster currently just uses the default security
+                    // configuration
                     .setHostnameVerifier(NoopHostnameVerifier.INSTANCE)
                     // See please https://issues.apache.org/jira/browse/HTTPCLIENT-2219
                     .setTlsDetailsFactory(new Factory<SSLEngine, TlsDetails>() {
@@ -76,9 +111,11 @@ public TlsDetails create(final SSLEngine sslEngine) {
 
     /**
      * Creates OpenSearchClient for SDK. It also creates a restClient as a wrapper around Java OpenSearchClient
+     *
      * @param hostAddress The address of OpenSearch cluster, client can connect to
-     * @param port The port of OpenSearch cluster
-     * @return The SDKClient implementation of OpenSearchClient. The user is responsible for calling {@link #doCloseJavaClient()} when finished with the client
+     * @param port        The port of OpenSearch cluster
+     * @return The SDKClient implementation of OpenSearchClient. The user is responsible for calling
+     *         {@link #doCloseJavaClient()} when finished with the client
      */
     public OpenSearchClient initializeJavaClient(String hostAddress, int port) {
         RestClientBuilder builder = builder(hostAddress, port);
@@ -99,18 +136,23 @@ public OpenSearchClient initializeJavaClient(String hostAddress, int port) {
     }
 
     /**
-     * @deprecated Provided for compatibility with existing plugins to permit migration. New development should not use this client
-     * Creates High Level Rest Client for SDK.
+     * Initializes a SDK Rest Client wrapping the {@link RestHighLevelClient}.
+     * <p>
+     * The purpose of this client is to provide a drop-in replacement for the syntax of the {@link Client}
+     * implementation in existing plugins with a minimum of code changes.
+     * <p>
+     * Do not use this client for new development.
+     *
      * @param hostAddress The address of OpenSearch cluster, client can connect to
-     * @param port The port of OpenSearch cluster
-     * @return The SDKClient implementation of RestHighLevelClient. The user is responsible for calling {@link #doCloseHighLevelClient()} when finished with the client
+     * @param port        The port of OpenSearch cluster
+     * @return The SDKClient implementation of RestHighLevelClient. The user is responsible for calling
+     *         {@link #doCloseHighLevelClient()} when finished with the client
+     * @deprecated Provided for compatibility with existing plugins to permit migration. Use
+     *             {@link #initializeJavaClient} for new development.
      */
     @Deprecated
-    public RestHighLevelClient initializeRestClient(String hostAddress, int port) {
-        RestClientBuilder builder = builder(hostAddress, port);
-
-        highLevelClient = new RestHighLevelClient(builder);
-        return highLevelClient;
+    public SDKRestClient initializeRestClient(String hostAddress, int port) {
+        return new SDKRestClient(new RestHighLevelClient(builder(hostAddress, port)));
     }
 
     /**
@@ -130,8 +172,8 @@ public void doCloseJavaClient() throws IOException {
      * @throws IOException if closing the highLevelClient fails
      */
     public void doCloseHighLevelClient() throws IOException {
-        if (highLevelClient != null) {
-            highLevelClient.close();
+        if (sdkRestClient != null) {
+            sdkRestClient.close();
         }
     }
 
@@ -140,4 +182,209 @@ public void close() throws IOException {
         doCloseJavaClient();
         doCloseHighLevelClient();
     }
+
+    /**
+     * Wraps an internal {@link RestHighLevelClient} using method signatures expected by {@link Client} and {@link org.opensearch.client.AdminClient} syntax, providing a drop-in replacement in existing plugins with a minimum of code changes.
+     * <p>
+     * While some {@link Client} interface methods are implemented here, the interface is intentionally not fully implemented as it is intended to be deprecated.
+     * <p>
+     * Do not use this client for new development.
+     *
+     * @deprecated Use {@link org.opensearch.client.opensearch.OpenSearchClient}.
+     * @see <a href="https://github.com/opensearch-project/OpenSearch/issues/5424">OpenSearch Issue 5424</a>
+     */
+    @Deprecated
+    public static class SDKRestClient implements Closeable {
+
+        private final RestHighLevelClient restHighLevelClient;
+
+        /**
+         * Instantiate this class wrapping a {@link RestHighLevelClient}.
+         *
+         * @param restHighLevelClient The client to wrap.
+         */
+        public SDKRestClient(RestHighLevelClient restHighLevelClient) {
+            this.restHighLevelClient = restHighLevelClient;
+        }
+
+        /**
+         * The admin client that can be used to perform administrative operations.
+         */
+        public SDKRestClient admin() {
+            return this;
+        }
+
+        /**
+         * A client allowing to perform actions/operations against the cluster.
+         */
+        public SDKClusterAdminClient cluster() {
+            return new SDKClusterAdminClient(restHighLevelClient.cluster());
+        }
+
+        /**
+         * A client allowing to perform actions/operations against the indices.
+         */
+        public SDKIndicesClient indices() {
+            return new SDKIndicesClient(restHighLevelClient.indices());
+        }
+
+        /**
+         * Index a document associated with a given index.
+         * <p>
+         * The id is optional, if it is not provided, one will be generated automatically.
+         *
+         * @param request  The index request
+         * @param listener A listener to be notified with a result
+         * @see Requests#indexRequest(String)
+         */
+        public void index(IndexRequest request, ActionListener<IndexResponse> listener) {
+            restHighLevelClient.indexAsync(request, RequestOptions.DEFAULT, listener);
+        }
+
+        /**
+         * Gets the document that was indexed from an index with an id.
+         *
+         * @param request  The get request
+         * @param listener A listener to be notified with a result
+         * @see Requests#getRequest(String)
+         */
+        public void get(GetRequest request, ActionListener<GetResponse> listener) {
+            restHighLevelClient.getAsync(request, RequestOptions.DEFAULT, listener);
+        }
+
+        /**
+         * Deletes a document from the index based on the index, and id.
+         *
+         * @param request  The delete request
+         * @param listener A listener to be notified with a result
+         * @see Requests#deleteRequest(String)
+         */
+        public void delete(DeleteRequest request, ActionListener<DeleteResponse> listener) {
+            restHighLevelClient.deleteAsync(request, RequestOptions.DEFAULT, listener);
+        }
+
+        /**
+         * Search across one or more indices with a query.
+         *
+         * @param request  The search request
+         * @param listener A listener to be notified of the result
+         * @see Requests#searchRequest(String...)
+         */
+        public void search(SearchRequest request, ActionListener<SearchResponse> listener) {
+            restHighLevelClient.searchAsync(request, RequestOptions.DEFAULT, listener);
+        }
+
+        @Override
+        public void close() throws IOException {
+            restHighLevelClient.close();
+        }
+    }
+
+    /**
+     * Wraps an internal {@link ClusterAdminClient}, providing a drop-in replacement in existing plugins with a minimum of code changes.
+     * <p>
+     * Do not use this client for new development.
+     */
+    public static class SDKClusterAdminClient {
+
+        private final ClusterClient clusterClient;
+
+        /**
+         * Instantiate this class using a {@link ClusterClient}.
+         *
+         * @param clusterClient The client to wrap
+         */
+        public SDKClusterAdminClient(ClusterClient clusterClient) {
+            this.clusterClient = clusterClient;
+        }
+
+        // TODO: Implement state()
+        // https://github.com/opensearch-project/opensearch-sdk-java/issues/354
+
+    }
+
+    /**
+     * Wraps an internal {@link IndicesClient}, providing a drop-in replacement in existing plugins with a minimum of code changes.
+     * <p>
+     * Do not use this client for new development.
+     */
+    public static class SDKIndicesClient {
+
+        private final IndicesClient indicesClient;
+
+        /**
+         * Instantiate this class wrapping an {@link IndicesClient}.
+         *
+         * @param indicesClient The client to wrap
+         */
+        public SDKIndicesClient(IndicesClient indicesClient) {
+            this.indicesClient = indicesClient;
+        }
+
+        /**
+         * Asynchronously creates an index using the Create Index API.
+         *
+         * @param createIndexRequest the request
+         * @param listener the listener to be notified upon request completion
+         * @return cancellable that may be used to cancel the request
+         */
+        public Cancellable create(CreateIndexRequest createIndexRequest, ActionListener<CreateIndexResponse> listener) {
+            return indicesClient.createAsync(createIndexRequest, RequestOptions.DEFAULT, listener);
+        }
+
+        /**
+         * Asynchronously deletes an index using the Delete Index API.
+         *
+         * @param deleteIndexRequest the request
+         * @param listener the listener to be notified upon request completion
+         * @return cancellable that may be used to cancel the request
+         */
+        public Cancellable delete(DeleteIndexRequest deleteIndexRequest, ActionListener<AcknowledgedResponse> listener) {
+            return indicesClient.deleteAsync(deleteIndexRequest, RequestOptions.DEFAULT, listener);
+        }
+
+        /**
+         * Asynchronously updates the mappings on an index using the Put Mapping API.
+         *
+         * @param putMappingRequest the request
+         * @param listener the listener to be notified upon request completion
+         * @return cancellable that may be used to cancel the request
+         */
+        public Cancellable putMapping(PutMappingRequest putMappingRequest, ActionListener<AcknowledgedResponse> listener) {
+            return this.indicesClient.putMappingAsync(putMappingRequest, RequestOptions.DEFAULT, listener);
+        }
+
+        /**
+         * Asynchronously retrieves the mappings on an index on indices using the Get Mapping API.
+         *
+         * @param getMappingsRequest the request
+         * @param listener the listener to be notified upon request completion
+         * @return cancellable that may be used to cancel the request
+         */
+        public Cancellable getMapping(GetMappingsRequest getMappingsRequest, ActionListener<GetMappingsResponse> listener) {
+            return this.indicesClient.getMappingAsync(getMappingsRequest, RequestOptions.DEFAULT, listener);
+        }
+
+        /**
+         * Asynchronously rolls over an index using the Rollover Index API.
+         *
+         * @param rolloverRequest the request
+         * @param listener the listener to be notified upon request completion
+         * @return cancellable that may be used to cancel the request
+         */
+        public Cancellable rolloverIndex(RolloverRequest rolloverRequest, ActionListener<RolloverResponse> listener) {
+            return this.indicesClient.rolloverAsync(rolloverRequest, RequestOptions.DEFAULT, listener);
+        }
+
+        /**
+         * Asynchronously gets one or more aliases using the Get Index Aliases API.
+         *
+         * @param getAliasesRequest the request
+         * @param listener the listener to be notified upon request completion
+         * @return cancellable that may be used to cancel the request
+         */
+        public Cancellable getAliases(GetAliasesRequest getAliasesRequest, ActionListener<GetAliasesResponse> listener) {
+            return this.indicesClient.getAliasAsync(getAliasesRequest, RequestOptions.DEFAULT, listener);
+        }
+    }
 }