Move RPC byte-counting logic to separate gRPC stream wrappers

[iain-macdonald]

No description provided.

[bduffany]

what was wrong with bytesRead += proto.Size(rsp)? the stream wrapper seems comparatively more complicated 🤔

[iain-macdonald]

what was wrong with bytesRead += proto.Size(rsp)? the stream wrapper seems comparatively more complicated 🤔

My thinking here is that it would be nice to have gRPC-level logging for bytes sent over the wire, like the request and latency metrics available from go-grpc-middleware and adding these stream-wrappers is a step towards doing that. Not super tied to the idea at the moment though if you feel it's not worth the extra complexity in that grpc_stream package.

[tylerwilliams]

Does prometheus grpc middleware not provide this?

[iain-macdonald]

Does prometheus grpc middleware not provide this?

It does not.

[bduffany]

@iain-macdonald got it - would it make sense to do this using custom gRPC middleware? (in interceptors.go)

(we do some server stream wrapping there already)