Add HTTP/2 protocol support to HttpRequest.HttpVersion (#17248)

Signed-off-by: Andriy Redko <andriy.redko@aiven.io>

Author: reta

CHANGELOG-3.0.md

@@ -57,7 +57,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Fix compression support for h2c protocol ([#4944](https://github.com/opensearch-project/OpenSearch/pull/4944))
 - Don't over-allocate in HeapBufferedAsyncEntityConsumer in order to consume the response ([#9993](https://github.com/opensearch-project/OpenSearch/pull/9993))
 - Fix swapped field formats in nodes API where `total_indexing_buffer_in_bytes` and `total_indexing_buffer` values were reversed ([#17070](https://github.com/opensearch-project/OpenSearch/pull/17070))
-
+- Add HTTP/2 protocol support to HttpRequest.HttpVersion ([#17248](https://github.com/opensearch-project/OpenSearch/pull/17248))
 
 ### Security
 

modules/transport-netty4/src/main/java/org/opensearch/http/netty4/Netty4HttpRequest.java

@@ -217,6 +217,8 @@ public HttpVersion protocolVersion() {
             return HttpRequest.HttpVersion.HTTP_1_0;
         } else if (request.protocolVersion().equals(io.netty.handler.codec.http.HttpVersion.HTTP_1_1)) {
             return HttpRequest.HttpVersion.HTTP_1_1;
+        } else if (request.protocolVersion().equals("HTTP/2.0")) {
+            return HttpRequest.HttpVersion.HTTP_2_0;
         } else {
             throw new IllegalArgumentException("Unexpected http protocol version: " + request.protocolVersion());
         }

plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpRequest.java

@@ -156,6 +156,8 @@ public HttpVersion protocolVersion() {
             return HttpRequest.HttpVersion.HTTP_1_0;
         } else if (protocol.equals(io.netty.handler.codec.http.HttpVersion.HTTP_1_1.toString())) {
             return HttpRequest.HttpVersion.HTTP_1_1;
+        } else if (protocol.equals("HTTP/2.0")) {
+            return HttpRequest.HttpVersion.HTTP_2_0;
         } else {
             throw new IllegalArgumentException("Unexpected http protocol version: " + protocol);
         }

server/src/main/java/org/opensearch/http/HttpRequest.java

@@ -59,7 +59,8 @@ public interface HttpRequest {
     @PublicApi(since = "1.0.0")
     enum HttpVersion {
         HTTP_1_0,
-        HTTP_1_1
+        HTTP_1_1,
+        HTTP_2_0
     }
 
     /**