The main goals of Elasticsearch are indexing, searching, and analytics, but it's often required to modify or enhance the documents before storing in Elasticsearch.
The most common scenarios in this case are:
Preprocessing the log string to extract meaningful data.
Enrich the content of some textual fields with Natural Language Processing (NLP) tools.
Add some transformation during ingestion such as convert IP in geolocalization or build custom fields at ingest time
You need a working Elasticsearch installation as we described in the Downloading and installing Elasticsearch recipe and a simple text editor to change configuration files.
To set up an ingest node, you need to edit the config/elasticsearch.yml file and set up the ingest property to true:
node.ingest: true
The default configuration for Elasticsearch is to set the node as ingest node (refer to Chapter 13, Ingest, for more info on ingestion pipeline).
As the client node...
