Reuse client option to configure server recv limit

[itwalton]

Motivation

Tried using the backend_max_call_recv_msg_size arg to send 5Mb message from browser front-end -> grpcwebproxy -> backend service. Proxy was throwing error (below). It looked like the server was still using the GRPC default message size of 4Mb.

Changes

1. Apply existing CLI arg backend_max_call_recv_msg_size to proxy server

Verification

Setup

• Go version: go version go1.13.4 darwin/amd64
• OS: macOS

message UploadRequest {
  bytes file = 1;
}

message FooService {
  rpc Upload (UploadRequest) returns (...) {}
}

// create client
 const grpcClient = new FooServiceDefinition('localhost:8443', {
    transport: grpc.WebsocketTransport()
  })

Steps to reproduce

1. Run proxy, built from source, with command $GOPATH/bin/grpcwebproxy --backend_max_call_recv_msg_size=5242880 --backend_addr=localhost:50053 --server_http_debug_port=8443 --run_tls_server=false --use_websockets --allow_all_origins

2. Call grpcClient.upload w/ 5Mb request; received error:

ERRO[0026] finished streaming call with code Internal error="rpc error: code = Internal desc = failed proxying s2c: rpc error: code = ResourceExhausted desc = grpc: received message larger than max (5242880 vs. 4194304)" grpc.code=Internal grpc.method=Upload grpc.service=FooService ...

3. Build w/ fix; request successful

[johanbrandhorst]

Nice, yeah, I think this makes sense, I imagine you always want the server and client limit to be matching up in this case.

[itwalton]

Apologies for neglecting the tests. Will fix tonight.

[johanbrandhorst]

Apologies for neglecting the tests. Will fix tonight.

I think this is a flake. Let me rerun it.

[johanbrandhorst]

Thanks for your contribution!