[Backport 1.x] Initial Hello World Extension integration test

build.gradle

@@ -273,10 +273,15 @@ task integTest(type: RestIntegTestTask) {
     testClassesDirs = sourceSets.test.output.classesDirs
     classpath = sourceSets.test.runtimeClasspath
 }
-//tasks.named("check").configure { dependsOn(integTest) }
-
-task startTestExtension(type: Exec) {
-    commandLine 'bash', '-c', "./gradlew helloWorld &"
+tasks.named("check").configure { dependsOn(integTest) }
+
+task startTestExtension {
+    doFirst{
+        ext.process = new ProcessBuilder()
+                .directory(projectDir)
+                .command("./gradlew", "helloWorld")
+                .start()
+    }
 }
 
 integTest {
@@ -310,10 +315,12 @@ integTest {
     }
 }
 
-def testExtensionYml = new org.yaml.snakeyaml.Yaml().load(new File("src/test/resources/hello-world-extension.yml").newInputStream())
-
-task closeTestExtension (type: Exec) {
-    commandLine 'bash', '-c', "kill \$(lsof -i:${testExtensionYml.port})"
+task closeTestExtension {
+    doFirst {
+        if (tasks.startTestExtension.process != null) {
+            tasks.startTestExtension.process.destroy()
+        }
+    }
 }
 
 tasks.named("integTest").configure { finalizedBy(closeTestExtension) }
@@ -333,5 +340,4 @@ testClusters.integTest {
             debugPort += 1
         }
     }
-
 }

src/test/java/org/opensearch/sdk/sample/helloworld/rest/TestHelloWorldIT.java

@@ -0,0 +1,124 @@
+/*
+ * Copyright OpenSearch Contributors
+ * 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.sample.helloworld.rest;
+
+import java.io.IOException;
+import java.util.Map;
+import java.util.concurrent.Callable;
+
+import org.apache.http.HttpEntity;
+import org.apache.http.entity.ContentType;
+import org.apache.http.entity.StringEntity;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.junit.Test;
+import org.opensearch.client.Request;
+import org.opensearch.client.Response;
+import org.opensearch.client.RestClient;
+import org.opensearch.rest.RestStatus;
+import org.opensearch.test.rest.OpenSearchRestTestCase;
+
+public class TestHelloWorldIT extends OpenSearchRestTestCase {
+    private static final Logger logger = LogManager.getLogger(TestHelloWorldIT.class);
+
+    public static final String EXTENSION_INIT_URI = "/_extensions/initialize/";
+    public static final String HELLO_WORLD_EXTENSION_BASE_URI = "/_extensions/_hello-world";
+    public static final String HELLO_BASE_URI = HELLO_WORLD_EXTENSION_BASE_URI + "/hello";
+    public static final String HELLO_NAME_URI = HELLO_BASE_URI + "/%s";
+    public static final String GOODBYE_URI = HELLO_WORLD_EXTENSION_BASE_URI + "/goodbye";
+
+    // TODO : Move extension initialization to setUp method prior to adding addtional tests
+
+    @Test
+    public void testInitializeExtension() throws Exception {
+        // Send initialization request
+        String helloWorldInitRequestBody = "{\"name\":\"hello-world\""
+            + ",\"uniqueId\":\"hello-world\""
+            + ",\"hostAddress\":\"127.0.0.1\""
+            + ",\"port\":\"4500\""
+            + ",\"version\":\"1.0\""
+            + ",\"opensearchVersion\":\"2.9.0\""
+            + ",\"minimumCompatibleVersion\":\"2.9.0\"}";
+        Response response = makeRequest(client(), "POST", EXTENSION_INIT_URI, null, toHttpEntity(helloWorldInitRequestBody));
+
+        assertEquals(RestStatus.ACCEPTED, restStatus(response));
+        Map<String, Object> responseMap = entityAsMap(response);
+        String initializationResponse = (String) responseMap.get("success");
+        assertEquals("A request to initialize an extension has been sent.", initializationResponse);
+    }
+
+    /**
+     * Retrieves the REST status from a response
+     *
+     * @param response the REST response
+     * @return the RestStatus of the response
+     *
+     */
+    private static RestStatus restStatus(Response response) {
+        return RestStatus.fromCode(response.getStatusLine().getStatusCode());
+    }
+
+    /**
+     * Converts a JSON string into an HttpEntity
+     *
+     * @param jsonString The JSON string
+     * @return the HttpEntity
+     *
+     */
+    private static HttpEntity toHttpEntity(String jsonString) throws IOException {
+        return new StringEntity(jsonString, ContentType.APPLICATION_JSON);
+    }
+
+    /**
+     * Helper method to send a REST Request
+     *
+     * @param client The REST client
+     * @param method The request method
+     * @param endpoint The REST endpoint
+     * @param params The request parameters
+     * @param entity The request body
+     * @return the REST response
+     *
+     */
+    private static Response makeRequest(RestClient client, String method, String endpoint, Map<String, String> params, HttpEntity entity)
+        throws IOException {
+
+        // Create request
+        Request request = new Request(method, endpoint);
+        if (params != null) {
+            params.entrySet().forEach(it -> request.addParameter(it.getKey(), it.getValue()));
+        }
+        if (entity != null) {
+            request.setEntity(entity);
+        }
+        return client.performRequest(request);
+    }
+
+    /**
+     * Invokes the callable method and asserts that the expected exception is thrown with the given exception message
+     *
+     * @param clazz The exception class
+     * @param message The exception message
+     * @param callable The callable request method
+     *
+     */
+    private static <S, T> void assertFailWith(Class<S> clazz, String message, Callable<T> callable) throws Exception {
+        try {
+            callable.call();
+        } catch (Throwable e) {
+            if (e.getClass() != clazz) {
+                throw e;
+            }
+            if (message != null && !e.getMessage().contains(message)) {
+                throw e;
+            }
+        }
+    }
+}