Creating an ingest plugin

Elasticsearch 5.x introduces the ingest node that allows the modification, via a pipeline, to the records before ingesting in Elasticsearch. We have already seen in Chapter 13, Ingest that a pipeline is composed by one or more processor action. In this recipe, we will see how to create a custom processor that store in a field the initial character of another one.

Getting ready

You need an up-and-running Elasticsearch installation as we described in the Downloading and installing Elasticsearch recipe in Chapter 2, Downloading and Setup.

A Maven tool, or an IDE that support Java programming, such as Eclipse or IntelliJ IDEA. The code for this recipe is available in the chapter17/ingest_plugin directory.

How to do it...

To create an ingest processor plugin, we need to create the processor and then register it in the plugin class. We will perform the following steps:

1. We create the processor and its factory:

           ... 
           public final class InitialProcessor extends...