Make the plugin compatible with 2.x.

Signed-off-by: dblock <[email protected]>

README.md

@@ -21,12 +21,12 @@ Check out OpenSearch code, run it once with `./gradlew run`.
 Install the plugin, you may need to adjust `darwin-arm64-tar` below to your platform, and use the location of your plugin zip.
 
 ```sh
-$ ./distribution/archives/darwin-arm64-tar/build/install/opensearch-3.0.0-SNAPSHOT/bin/opensearch-plugin install file:///Users/dblock/source/opensearch-project/opensearch-api/dblock-opensearch-api/build/distributions/opensearch-api.zip
+$ ./distribution/archives/darwin-arm64-tar/build/install/opensearch-2.12.0-SNAPSHOT/bin/opensearch-plugin install file:///Users/dblock/source/opensearch-project/opensearch-api/dblock-opensearch-api/build/distributions/opensearch-api.zip
 
 -> Installed opensearch-api with folder name opensearch-api
 ```
 
-When you run OpenSeaerch with `./gradlew run` you should see the plugin loaded in the logs.
+When you run OpenSearch with `./gradlew run` you should see the plugin loaded in the logs.
 
 ```
 [2023-09-27T08:35:48,627][INFO ][o.o.p.PluginsService] [runTask-0] loaded plugin [opensearch-api]
@@ -41,7 +41,7 @@ $ curl http://localhost:9200/_plugins/api
 ### Uninstall
 
 ```sh
-./distribution/archives/darwin-arm64-tar/build/install/opensearch-3.0.0-SNAPSHOT/bin/opensearch-plugin remove opensearch-api
+./distribution/archives/darwin-arm64-tar/build/install/opensearch-2.12.0-SNAPSHOT/bin/opensearch-plugin remove opensearch-api
 
 -> removing [opensearch-api]...
 ```

build.gradle

@@ -65,7 +65,7 @@ javadoc.enabled = false
 
 buildscript {
     ext {
-        opensearch_version = System.getProperty("opensearch.version", "3.0.0-SNAPSHOT")
+        opensearch_version = System.getProperty("opensearch.version", "2.12.0-SNAPSHOT")
     }
 
     repositories {

src/test/java/org/opensearch/plugin/api/APIPluginIT.java

@@ -9,8 +9,7 @@
 
 import com.carrotsearch.randomizedtesting.annotations.ThreadLeakScope;
 
-import org.apache.hc.core5.http.ParseException;
-import org.apache.hc.core5.http.io.entity.EntityUtils;
+import org.apache.http.util.EntityUtils;
 import org.opensearch.client.Request;
 import org.opensearch.client.Response;
 import org.opensearch.plugins.Plugin;
@@ -30,15 +29,15 @@ protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Collections.singletonList(APIPlugin.class);
     }
 
-    public void testPluginInstalled() throws IOException, ParseException {
+    public void testPluginInstalled() throws IOException {
         Response response = getRestClient().performRequest(new Request("GET", "/_cat/plugins"));
         String body = EntityUtils.toString(response.getEntity(), StandardCharsets.UTF_8);
 
-        logger.info("response body: {}", body.toString());
+        logger.info("response body: {}", body);
         assertTrue(body.contains("api"));
     }
 
-    public void testPluginGetAPI() throws IOException, ParseException {
+    public void testPluginGetAPI() throws IOException {
         Response response = getRestClient().performRequest(new Request("GET", "/_plugins/api"));
         String body = EntityUtils.toString(response.getEntity(), StandardCharsets.UTF_8);
         logger.info("response body: {}", body);