No grpc reponse from Javascript client request

[DaveO-Home]

The Helidon gRPC correctly accepts the Javascript gRPC request. However, there is no or just null response from the server.

Environment Details

build.date 2023-08-03 16:19:35 UTC build.version 3.0.6 build.revision 0c0d6790 project.version 1.0.0 project.helidon.version 4.1.2 project.flavor MP latest.helidon.version 4.1.3 default.helidon.version 4.1.3 Java(TM) SE Runtime Environment Oracle GraalVM 21.0.2+13.1 (build 21.0.2+13-LTS-jvmci-23.1-b30) Java HotSpot(TM) 64-Bit Server VM Oracle GraalVM 21.0.2+13.1 (build 21.0.2+13-LTS-jvmci-23.1-b30, mixed mode, sharing)

---

Sample Code:

import com.google.protobuf.Descriptors;
import golf.handicap.Golfer;
import handicap.grpc.HandicapData;
import handicap.grpc.HandicapProto;
import handicap.grpc.HandicapSetup;
import io.grpc.stub.StreamObserver;
import io.helidon.grpc.core.ResponseHelper;
import io.helidon.webserver.grpc.GrpcService;
import jakarta.json.Json;
import jakarta.json.JsonObject;
import jakarta.json.bind.JsonbBuilder;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

public class HandicapService implements GrpcService {
    private static final Logger logger = LogManager.getLogger(HandicapService.class.getName());

    public HandicapService() {
    }

    public void getGolfer(HandicapSetup request, StreamObserver<HandicapData> observer) {
        logger.info("Doing GetGolfer***********************: {}", request);
        JsonObject requestJson = Json.createObjectBuilder().add("data", request.getJson()).build();
        Golfer currentGolfer = JsonbBuilder.create().fromJson(requestJson.getString("data"), Golfer.class);
        /*
            Call logic with (currentGolfer) not implemented - sending back requested data
        */
        logger.info("Returning Data: {}", requestJson.getJsonString("data").getString());
        HandicapData handicapData = HandicapData.newBuilder()
          .setMessage("No Golfer Found")
          .setCmd(request.getCmd())
          .setJson(requestJson.getJsonString("data").getString())
          .build();
        ResponseHelper.complete(observer, handicapData);
    }

    @Override
    public Descriptors.FileDescriptor proto() {
        return HandicapProto.getDescriptor();
    }

    @Override
    public void update(Routing routing) {
        routing.unary(
          "GetGolfer", this::getGolfer
        );
    }
}

The proto:

// import "google/protobuf/struct.proto";

option java_multiple_files = true;
option java_package = "handicap.grpc";
option java_outer_classname = "HandicapProto";

package handicap.grpc;

service HandicapService {
  rpc ListCourses(Command) returns (ListCoursesResponse) {}
  rpc AddRating(Command) returns (HandicapData) {}
  rpc AddScore(Command) returns (HandicapData) {}
  rpc RemoveScore(Command) returns (HandicapData) {}
  rpc GolferScores(Command) returns (HandicapData) {}
  rpc GetGolfer (HandicapSetup) returns (HandicapData) {}
  rpc ListGolfers (Command) returns (ListPublicGolfers) {}
}

message HandicapSetup {
  int32 cmd = 1;
  string json = 2;
  string message = 3;
}

message HandicapData {
  int32 cmd = 1;
  string json = 2;
  string message = 3;
}

message Rating {
  int32 tee = 1;
  string rating = 2;
  int32 slope = 3;
  int32 par = 4;
  string color = 5;
  int32 seq = 6;
}
message Course {
  int32 id = 1;
  string name = 2;
  repeated Rating ratings = 3;
}

message ListCoursesResponse {
  repeated Course courses = 1;
}

message Golfer {
  string name = 1;
}

message ListPublicGolfers {
  repeated Golfer golfer = 1;
}

message Command {
  int32 cmd = 1;
  string key = 2;
  string json = 3;
}

The data the Helidon server accepts:

2024-10-31 17:09:11 (HandicapService:25) - INFO Doing GetGolfer***********************: cmd: 3
json: "{\"pin\":\"xx1234\",\"firstName\":\"\",\"lastName\":\"\",\"country\":\"US\",\"state\":\"AL\",\"overlap\":false,\"public\":false,\"status\":0,\"lastLogin\":\"1730419751853\",\"course\":\"\",\"tee\":\"2\",\"teeDate\":\"1730419751853\"}"
message: "Golfer Data"  #105  

Data the Server responses with:

2024-10-31 17:09:11 (HandicapService:29) - INFO Returning Data: 2024-10-31 17:35:23 (HandicapService:36) - INFO Returning Data:
 cmd: 3
json: "{\"pin\":\"xx1234\",\"firstName\":\"\",\"lastName\":\"\",\"country\":\"US\",\"state\":\"AL\",\"overlap\":false,\"public\":false,\"status\":0,\"lastLogin\":\"1730421323634\",\"course\":\"\",\"tee\":\"2\",\"teeDate\":\"1730421323634\"}"
message: "No Golfer Found" #105

Note: There is an Envoy proxy between the client/server. Does CORS and HTTP: 2

[DaveO-Home]

"Is your Javascript client assuming dynamic resolution of the proto file?" The client only posts the application data, it might be passing meta data under the covers. I don't see that the poxy is an issue because the grpcurl query works.

grpcurl -plaintext -d '{"cmd":3,"json":"{\"pin\":\"do1234\"}","message":"get golfer"}'
 -vv -proto src/main/proto/handicap.proto localhost:8071 handicap.grpc.HandicapService/GetGolfer

port 8071 is the proxy. The query also works via port 8061 the helidon webserver port since grpcurl works with http2. But again the proto file is required.

[spericas]

@DaveO-Home Could provide more info about the JS client part? The library and the JS client code that gets a null response?

[DaveO-Home]

You can find the code at: https://github.com/DaveO-Home/dodex-quarkus/tree/master/src/grpc/client This is a Quarkus framework that has the same code. The only difference is that in the handiap.proto file the Service was changed for HandicapIndex to HandicapService. Files of interest: proto bash script that generates the code in ./js/handicap, the gRPC javascript client. The proto is in ./protos/handicap/ This same setup on Quarkus works without the -proto parameter.

[spericas]

Related to issue #9454

[DaveO-Home]

Thanks, - Question, why does the request work and the response fails. Doesn't the request require reflection?