Creating a REST plugin

The previous recipe described how to set up an environment and the steps required to build a simple plugins. In this recipe, we will see how to create one of the most common ElasticSearch plugin, the REST one.

These kinds of plugins allow extending the standard REST calls with custom ones to easily improve the capabilities of ElasticSearch.

In this recipe we will see how to define a REST entry point and in the next one how to execute this action distributed in shards.

Getting ready

You need a working ElasticSearch node, a maven built tool, and an optional Java IDE. The code of this recipe is available in the chapter12/rest_plugin directory.

How to do it...

To create a REST entry point, we need to create the action and then register it in the plugin. We need to perform the following steps:

1. We create a REST "simple" action (RestSimpleAction.java):

   …
   public class RestSimpleAction extends BaseRestHandler {
       @Inject
       public RestSimpleAction(Settings settings...