Creating a REST plugin

In the previous recipe, we read how to build an analyzer plugin that extends the query capabilities of Elasticsearch. In this recipe, we will see how to create one of the most common Elasticsearch plugins. This kind of plugin allows the standard REST calls to be extended with custom ones to easily improve the capabilities of Elasticsearch.

In this recipe, we will see how to define a REST entry point and create its action; in the next one, we'll see how to execute this action distributed in shards.

Getting ready

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

Gradle or an integrated development environment (IDE) that supports Java programming with Gradle (version 7.3.x used in the examples), such as Eclipse, Visual Studio Code, or IntelliJ IDEA, is required. Java JDK 17 or above needs to be installed.

The code for this recipe is available...