GRPC JSON transcoding : query parameters not "discovered"

This is about #167 and https://docs.microsoft.com/en-us/aspnet/core/grpc/httpapi?view=aspnetcore-5.0

Given the following proto

syntax = "proto3";

option csharp_namespace = "user_management";

import "google/api/annotations.proto";

service UserListService {
    //List users 
    rpc ListUsers (ListUserRequest) returns (UserList) {
        option (google.api.http) = {
            get: "/v1/users";
        };
    }
}

message ListUserRequest {
    int32 page_size = 1;
    int32 page_nb = 2;
    string order_by = 3;
    
    string name = 4;
}

message UserList {
    int32 total = 1;
    int32 page_nb = 2;
    repeated UserItem data = 3;
}

//Partial details for a user
message UserItem{
	string id = 1;
	string name = 2;
}

I would expect that ListUserRequest is exposed as query parameters

Indeed, calling http://localhost:5000/v1/users?page_size=10&page_nb=1 will correctly submit the parameters to the C# class

However, the generated swagger as explained at https://docs.microsoft.com/en-us/aspnet/core/grpc/httpapi?view=aspnetcore-5.0#enable-swaggeropenapi-support does not contain them

[christopheblin]

@JamesNK thanks for your answer

if there is no way to include them automatically, what is the way to include them explicitly ?

for ex, for post I can do :

option (google.api.http) = {
  post: "/v1/example/echo"
  body: "*"
};

however, there is no such thing for get (at least that I can see)

it seems wrong to do

option (google.api.http) = {
  get: "/v1/example/echo?message={message}"
};

another point (already said in the ticket, sorry for redundancy) is that if I call http://localhost:5000/v1/users?page_size=10&page_nb=1, then it will correctly submit the parameters to the C# class -> why are they not documented in the OpenApi part if I can use them (and because it is a GET, it is the ONLY possible way to use them anyway)

final point, the google docs https://cloud.google.com/endpoints/docs/grpc-service-config/reference/rpc/google.api#google.api.HttpRule

Any fields in the request message which are not bound by the path template automatically become HTTP query parameters if there is no HTTP request body.

Hope it helps to make a decision in my favor 😃 😃 😃

[JamesNK]

This is done in the OpenAPI integration for gRPC JSON transcoding:

https://learn.microsoft.com/en-us/aspnet/core/grpc/json-transcoding-openapi?view=aspnetcore-7.0