Filtering a search using scripting

In Chapter 4, Exploring Search Capabilities, we explored many filters. Elasticsearch scripting allows the extension of a traditional filter by using custom scripts.

Using scripting to create a custom filter is a convenient way to write scripting rules that are not provided by Lucene or Elasticsearch, and to implement business logic that is not available in a DSL query.

Getting ready

You will need an up-and-running Elasticsearch installation, similar to the one that we described in the Downloading and installing Elasticsearch recipe in Chapter 1, Getting Started.

To execute the commands, any HTTP client can be used, such as cURL (https://curl.haxx.se/) or Postman (https://www.getpostman.com/). You can use Kibana Console, as it provides code completion and better character escaping for Elasticsearch.

To correctly execute the following commands, you will need an index that is populated with the ch07/populate_aggregation.txt commands &...