[Backport 2.x] Adding x-amz-content-sha256 header for signed requests (#339)

CHANGELOG.md

@@ -20,6 +20,7 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 - Add timeout and throttle to the jenkins workflows ([#231](https://github.com/opensearch-project/opensearch-java/pull/231)) 
 - Update maintainers, admins and documentation ([#248](https://github.com/opensearch-project/opensearch-java/pull/248))
 - Update Gradle to 7.6 ([#311](https://github.com/opensearch-project/opensearch-java/pull/311))
+- Add support for OpenSearch Serverless ([#339](https://github.com/opensearch-project/opensearch-java/pull/339))
 
 ### Deprecated
 

DEVELOPER_GUIDE.md

@@ -67,10 +67,10 @@ Run integration tests after starting OpenSearch cluster:
 
 #### AWS Transport Integration Tests
 
-To run integration tests for the AWS transport client, ensure working AWS credentials and specify your OpenSearch domain and region as follows:
+To run integration tests for the AWS transport client, ensure working AWS credentials in `/.aws/credentials` and specify your OpenSearch domain and region as follows:
 
 ```
-./gradlew integrationTest --tests "*AwsSdk2*" -Dtests.awsSdk2support.domainHost=search-...us-west-2.es.amazonaws.com -Dtests.awsSdk2support.domainRegion=us-west-2
+./gradlew integrationTest --tests "*AwsSdk2*" -Dtests.awsSdk2support.domainHost=search-...us-west-2.es.amazonaws.com -Dtests.awsSdk2support.domainRegion=us-west-2 -Dtests.awsSdk2support.serviceName=es
 ```
 
 For OpenSearch Serverless, change the signing service name.

USER_GUIDE.md

@@ -166,7 +166,7 @@ DeleteIndexResponse deleteIndexResponse = client.indices().delete(deleteIndexReq
 
 ## Amazon Managed OpenSearch
 
-Use `AwsSdk2Transport` to make requests to Amazon Managed OpenSearch.
+Use `AwsSdk2Transport` to make requests to Amazon Managed OpenSearch and OpenSearch Serverless.
 
 ```java
 SdkHttpClient httpClient = ApacheHttpClient.builder().build();
@@ -175,7 +175,7 @@ OpenSearchClient client = new OpenSearchClient(
     new AwsSdk2Transport(
         httpClient,
         "search-...us-west-2.es.amazonaws.com", // OpenSearch endpoint, without https://
-        "es" // signing service name
+        "es" // signing service name, use "aoss" for OpenSearch Serverless
         Region.US_WEST_2, // signing service region
         AwsSdk2TransportOptions.builder().build()
     )

java-client/src/main/java/org/opensearch/client/transport/aws/AwsSdk2Transport.java

@@ -363,6 +363,9 @@ private <RequestT> SdkHttpFullRequest prepareRequest(
             }
             req.putHeader("Content-Length", String.valueOf(body.getContentLength()));
             req.contentStreamProvider(body::getInputStream);
+            // To add the "X-Amz-Content-Sha256" header, it needs to set as required.
+            // It is a required header for Amazon OpenSearch Serverless.
+            req.putHeader("x-amz-content-sha256", "required");
         }
 
         boolean responseCompression = Optional.ofNullable(options)

java-client/src/test/java/org/opensearch/client/opensearch/integTest/aws/AwsSdk2SearchIT.java

@@ -12,9 +12,7 @@
 import org.junit.Assert;
 import org.opensearch.client.opensearch.OpenSearchAsyncClient;
 import org.opensearch.client.opensearch.OpenSearchClient;
-import org.opensearch.client.opensearch._types.OpType;
 import org.opensearch.client.opensearch._types.OpenSearchException;
-import org.opensearch.client.opensearch._types.Refresh;
 import org.opensearch.client.opensearch.core.IndexRequest;
 import org.opensearch.client.opensearch.core.IndexResponse;
 import org.opensearch.client.opensearch.core.SearchResponse;
@@ -51,11 +49,14 @@ void testClient(boolean async) throws Exception {
         final OpenSearchClient client = getClient(async, null, null);
 
         SimplePojo doc1 = new SimplePojo("Document 1", "The text of document 1");
-        addDoc(client, "id1", doc1, false);
+        addDoc(client, "id1", doc1);
         SimplePojo doc2 = new SimplePojo("Document 2", "The text of document 2");
-        addDoc(client, "id2", doc2, false);
+        addDoc(client, "id2", doc2);
         SimplePojo doc3 = getLongDoc("Long Document 3", 1000000);
-        addDoc(client, "id3", doc3, true);
+        addDoc(client, "id3", doc3);
+
+        // wait for the document to index
+        Thread.sleep(1000);
 
         SearchResponse<SimplePojo> response = query(client, "NotPresent", null);
         Assert.assertEquals(0, response.hits().hits().size());
@@ -77,12 +78,15 @@ void testClientAsync(boolean async) throws Exception {
         final OpenSearchAsyncClient client = getAsyncClient(async, null, null);
 
         SimplePojo doc1 = new SimplePojo("Document 1", "The text of document 1");
-        CompletableFuture<IndexResponse> add1 = addDoc(client, "id1", doc1, false);
+        CompletableFuture<IndexResponse> add1 = addDoc(client, "id1", doc1);
         SimplePojo doc2 = new SimplePojo("Document 2", "The text of document 2");
-        CompletableFuture<IndexResponse> add2 = addDoc(client, "id2", doc2, false);
+        CompletableFuture<IndexResponse> add2 = addDoc(client, "id2", doc2);
         SimplePojo doc3 = getLongDoc("Long Document 3", 1000000);
         CompletableFuture<IndexResponse> add3 = CompletableFuture.allOf(add1, add2).thenCompose(
-                unused -> addDoc(client, "id3", doc3, true));
+                unused -> addDoc(client, "id3", doc3));
+
+        // wait for the document to index
+        Thread.sleep(1000);
 
         List<SearchResponse<SimplePojo>> results = add3.thenCompose(unused -> {
             CompletableFuture<SearchResponse<SimplePojo>> r1 = query(client, "NotPresent", null);
@@ -107,29 +111,21 @@ void testClientAsync(boolean async) throws Exception {
     }
 
 
-    private void addDoc(OpenSearchClient client, String id, SimplePojo doc, boolean wait) throws Exception {
+    private void addDoc(OpenSearchClient client, String id, SimplePojo doc) throws Exception {
         IndexRequest.Builder<SimplePojo> req = new IndexRequest.Builder<SimplePojo>()
                 .index(TEST_INDEX)
                 .document(doc)
-                .id(id)
-                .opType(OpType.Index);
-        if (wait) {
-            req.refresh(Refresh.WaitFor);
-        }
+                .id(id);
         client.index(req.build());
     }
 
     private CompletableFuture<IndexResponse> addDoc(
-            OpenSearchAsyncClient client, String id, SimplePojo doc, boolean wait
+            OpenSearchAsyncClient client, String id, SimplePojo doc
     ) {
         IndexRequest.Builder<SimplePojo> req = new IndexRequest.Builder<SimplePojo>()
                 .index(TEST_INDEX)
                 .document(doc)
-                .id(id)
-                .opType(OpType.Index);
-        if (wait) {
-            req.refresh(Refresh.WaitFor);
-        }
+                .id(id);
         try {
             return client.index(req.build());
         } catch (Exception e) {