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 12, Using the Ingest Module, that a pipeline is composed of one or more processor actions. In this recipe, we will see how to create a custom processor that stores in a field the initial character of another one.

Getting ready

You need an up and running Elasticsearch installation, as we described in Downloading and installing Elasticsearch recipe in Chapter 1, Getting Started.

Gradle or an IDE that supports Java programming with Gradle, such as Eclipse or IntelliJ IDEA, is required. The code...