Initial implementation of MLClient and workflow interface

build.gradle

@@ -53,6 +53,7 @@ opensearchplugin {
     noticeFile rootProject.file('NOTICE')
 }
 
+dependencyLicenses.enabled = false
 // This requires an additional Jar not published as part of build-tools
 loggerUsageCheck.enabled = false
 
@@ -62,6 +63,20 @@ validateNebulaPom.enabled = false
 buildscript {
     ext {
         opensearch_version = System.getProperty("opensearch.version", "3.0.0-SNAPSHOT")
+        buildVersionQualifier = System.getProperty("build.version_qualifier", "")
+        isSnapshot = "true" == System.getProperty("build.snapshot", "true")
+        version_tokens = opensearch_version.tokenize('-')
+        opensearch_build = version_tokens[0] + '.0'
+        plugin_no_snapshot = opensearch_build
+        if (buildVersionQualifier) {
+            opensearch_build += "-${buildVersionQualifier}"
+            plugin_no_snapshot += "-${buildVersionQualifier}"
+        }
+        if (isSnapshot) {
+            opensearch_build += "-SNAPSHOT"
+        }
+        opensearch_group = "org.opensearch"
+        opensearch_no_snapshot = opensearch_build.replace("-SNAPSHOT","")
         System.setProperty('tests.security.manager', 'false')
     }
 
@@ -89,7 +104,9 @@ repositories {
 
 dependencies {
     implementation "org.opensearch:opensearch:${opensearch_version}"
+    implementation 'org.junit.jupiter:junit-jupiter:5.8.1'
     compileOnly "com.google.guava:guava:32.1.2-jre"
+    api group: 'org.opensearch', name:'opensearch-ml-client', version: "${opensearch_build}"
 
     configurations.all {
         resolutionStrategy {

src/main/java/org/opensearch/flowframework/client/MLClient.java

@@ -0,0 +1,34 @@
+/*
+ * 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.flowframework.client;
+
+import org.opensearch.client.node.NodeClient;
+import org.opensearch.ml.client.MachineLearningNodeClient;
+
+/**
+ Class to initiate an instance of MLClient
+ */
+public class MLClient {
+    private static MachineLearningNodeClient INSTANCE;
+
+    private MLClient() {}
+
+    /**
+     * Creates machine learning client.
+     *
+     * @param nodeClient node client of OpenSearch.
+     * @return machine learning client from ml-commons.
+     */
+    public static MachineLearningNodeClient createMLClient(NodeClient nodeClient) {
+        if (INSTANCE == null) {
+            INSTANCE = new MachineLearningNodeClient(nodeClient);
+        }
+        return INSTANCE;
+    }
+}

src/main/java/org/opensearch/flowframework/workflow/Workflow.java

@@ -0,0 +1,22 @@
+/*
+ * 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.flowframework.workflow;
+
+/**
+ * Interface for the workflow setup of different building blocks.
+ */
+public interface Workflow {
+
+    /**
+     * Triggers the processing of the building block.
+     * @throws Exception if execution fails
+     */
+    void process() throws Exception;
+
+}

src/main/plugin-metadata/plugin-security.policy

@@ -0,0 +1,7 @@
+grant {
+    //ml-commons client
+    permission java.lang.RuntimePermission "getClassLoader";
+    permission java.lang.RuntimePermission "accessDeclaredMembers";
+    permission java.lang.reflect.ReflectPermission "suppressAccessChecks";
+    permission java.lang.RuntimePermission "setContextClassLoader";
+};