Python gRPC Request <> Reply not defined

Question

I am trying to setup an example Python gRPC example and have following proto file :

syntax = "proto3";

package greet;

service Greeter{

  // unary
  rpc SayHello (HelloRequest) returns (HelloReply);

  // Server Streaming
  rpc ParrotSayHello (HelloRequest) returns (stream HelloReply);

  // Client Streaming
  rpc ChattyClientSayHello (stream HelloRequest) returns (DelayedReply);

  // Both Streaming
  rpc InteractingHello (stream HelloReequest) returns (stream HelloReply);

}

The project structure is :

• Gretter
• |- protos

•   |- greet.protos
  

When I try running protoc using below :

 python -m grpc_tools.protoc -I./protos --python_out=. --grpc_python_out=. ./protos/greet.proto 

I get the error below:

greet.proto:8:17: "HelloRequest" is not defined.
greet.proto:8:40: "HelloReply" is not defined.
greet.proto:11:23: "HelloRequest" is not defined.
greet.proto:11:53: "HelloReply" is not defined.
greet.proto:14:36: "HelloRequest" is not defined.
greet.proto:14:59: "DelayedReply" is not defined.
greet.proto:17:32: "HelloReequest" is not defined.
greet.proto:17:63: "HelloReply" is not defined.

Pip list confirms I have the available packages:

(grpcenv) (base) ➜ Greeter pip list Package Version

---

grpcio 1.51.1 grpcio-tools 1.51.1 pip 22.3.1 protobuf 4.21.12 setuptools 57.0.0 wheel 0.36.2

Answer 1

I was reviewing the code and found the issue i.e. the proto was incorrect or rather incomplete.

The below proto resolved the issue (and the error was exactly what the problem was !!!)

syntax = "proto3";

package greet;

// The greeting service definition.
service Greeter {
    // Unary
    rpc SayHello (HelloRequest) returns (HelloReply);

    // Server Streaming
    rpc ParrotSaysHello (HelloRequest) returns (stream HelloReply);
    
    // Client Streaming
    rpc ChattyClientSaysHello (stream HelloRequest) returns (DelayedReply);

    // Both Streaming
    rpc InteractingHello (stream HelloRequest) returns (stream HelloReply);
}

// The request message containing the user's name.
message HelloRequest {
  string name = 1;
  string greeting = 2;
}

// The response message containing the greetings.
message HelloReply {
  string message = 1;
}

message DelayedReply {
    string message = 1;
    repeated HelloRequest request = 2;
}