Logstash plugin interface

Elastic Stack Logstash
1

Hello.

I'm documenting my elasticsearch + logstash solution and I was wondering how the connection between logstash and its plugins work.

Do the plugins implement any interface? Which? Or is this via HTTP?

To clarify my question, I'm trying to fill the "blanks" in this component diagram:
Screenshot_3

Thanks in advance

2

Logstash plugins are classes. Each plugin type (input, output, filter, codecc) subclasses a different class. Plugins execute within the Logstash process and communicate with the rest of Logstash via normal function calls.