add transform node role

x-pack/plugin/transform/src/main/java/org/elasticsearch/xpack/transform/Transform.java

@@ -15,6 +15,7 @@
 import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
 import org.elasticsearch.cluster.metadata.IndexTemplateMetaData;
 import org.elasticsearch.cluster.node.DiscoveryNode;
+import org.elasticsearch.cluster.node.DiscoveryNodeRole;
 import org.elasticsearch.cluster.node.DiscoveryNodes;
 import org.elasticsearch.cluster.service.ClusterService;
 import org.elasticsearch.common.io.stream.NamedWriteableRegistry;
@@ -112,6 +113,7 @@
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 import java.util.function.Supplier;
 import java.util.function.UnaryOperator;
 
@@ -157,6 +159,15 @@ public class Transform extends Plugin implements SystemIndexPlugin, PersistentTa
         Property.NodeScope
     );
 
+    public static final DiscoveryNodeRole TRANSFORM_ROLE = new DiscoveryNodeRole("transform", "t") {
+
+        @Override
+        protected Setting<Boolean> roleSetting() {
+            return TRANSFORM_ENABLED_NODE;
+        }
+
+    };
+
     public Transform(Settings settings) {
         this.settings = settings;
         this.enabled = XPackSettings.TRANSFORM_ENABLED.get(settings);
@@ -362,6 +373,11 @@ public Settings additionalSettings() {
         return additionalSettings.build();
     }
 
+    @Override
+    public Set<DiscoveryNodeRole> getRoles() {
+        return Collections.singleton(TRANSFORM_ROLE);
+    }
+
     @Override
     public void close() {
         if (transformServices.get() != null) {