Logstash is usually used to prepare the data before ingest to Elasticsearch. But Logstash has a lot of different input, filter and output plugins that can be used for various different use cases.

One use case could be to use Logstash as a script execution engine. This can be triggered via Watcher or Kibana Alerts and Actions to e.g. auto heal systems by restarting a machine. To achieve that Logstash needs to be able to accept Web Hook requests and decide based on the query parameters which script to execute.

Using this download you can make Logstash a REST endpoint that executes scripts or manually adds data in Elasticsearch.