Modified metadata not being passed on server-side streaming RPC

[ingnam]

Modified metadata not being passed on server-side streaming RPC

[splittingred]

Hey @ingnam - Thanks! gruf mainly uses the core grpc interceptors (it just has a base class for some convenience methods), so if there's an issue, it's likely there. A few questions to clarify:

1. What version of the gRPC gem are you using?
2. grpc essentially does this on the execute method (called lower-level by the call method on the client):

# c -> ActiveCall obj
# req -> request message
intercept_args = {
  method: method,
  request: req,
  call: c.interceptable,
  metadata: metadata
}
# ...
interception_context.intercept!(:server_streamer, intercept_args) do
  c.server_streamer(req, &blk)
end

And c.server_streamer in the base Gruf class just calls call:

      def server_streamer(request: nil, call: nil, method: nil, metadata: nil, &block)
        rc = Gruf::Outbound::RequestContext.new(
          type: :server_streamer,
          requests: [request],
          call: call,
          method: method,
          metadata: metadata
        )
        call(request_context: rc, &block)
      end

What happens if you use request_context.metadata[:tenant] = 'tenant_name' instead of a string key?

Other than that, my guess is that some reference in the c.merge_metadata_to_send(metadata) in the ClientStub grpc class is not maintained, which means modifications to the RequestContext metadata are not transitively persisted.

It may be a bit before I can get to this (shoulder injury), but that's the path of investigation I'd take.

[splittingred]

Closing this - feel free to re-open if you can answer the above question and provide more details on your grpc version. Thanks!