Detect which strfry instance is accessing the policy plugin

[alexgleason]

Finally found a potential use-case for extending the policy plugin input message: figuring out which instance of strfry originated the message (when multiple strfry policies use the same plugin on a shared machine).

Inspired by this thread: https://gitlab.com/soapbox-pub/strfry-policies/-/issues/4#note_1426085367

cc @Giszmo

btw, not sure it's even a good idea yet or the best solution to that problem, just want to brainstorm. strfry doesn't even know its own relay URL anyway, right? just the port it's running on.

[Giszmo]

For me the question is how could one policy plugin instance serve multiple strfry processes? My policy might grow quite heavy and I want to stream from probably more than 30 relays. There should be a better approach than to load and run the plugin 30 times in parallel.

I'm now thinking I could probably stream the 30 relays into one strfry instance without complex polilcy and stream that into my other using the full policy. The first instance would just act as a buffer and delete all events older than an hour.

[hoytech]

@alexgleason - Yes you're right, a strfry instance doesn't know its own relay URL. I guess we could have a config value where you could label an instance and that would get passed in to the policy plugin. I'm not sure, I'd like to hear more about your use-case so we can decide if that's the best approach.

@Giszmo - I am planning on making a strfry router command that would let you stream to/from multiple different relays, and they could all share a single policy plugin instance. I don't have a timeframe in mind for this yet, sorry. So many other things I want to do first. Nice idea about the buffer instance - that would actually probably work pretty well!

[Giszmo]

I want to offer a relay for limited/mobile clients, to connect to one relay, only. My relay would track the relay lists of accounts and stream/aggregate relevant events from those.