Event persistance

[mthenw]

I'm creating this issue to have one place where we can track efforts related to events persistance.

EG doesn't persist events, it's just a router but there are definitely use cases where we would like to persist events in some persistent store (DB, S3 Kafka) to be able to analyze them or event replay.

Persisting events is right now doable with creating plugin that will listen to gateway.event.received and send them somewhere. There is lack of examples and tutorials though.

TODO:

• provide examples
• ...

cc @alexdebrie

[alexdebrie]

@mthenw I like this idea. Some follow-up questions:

1. Do plugins work on a space-by-space basis, or on the Event Gateway as a whole? If the latter, is a plugin the right mechanism? Different spaces may want to have different persistence policies.

2. Could this be solved by Add a Kinesis provider #357 and related PRs to add additional providers (Kafka, Firehose, maybe databases)? This would allow users to add persistence via an additional subscription.