Protoc doesn't create service

Question

I am just trying to generate code for golang using protocol buffer. But unable to generate the service using protoc command.

syntax = "proto3";
package greet;
option go_package="./greet/greetpb";
service GreetService{}

Above is a dummy proto file that I am trying to convert into golang. But unable to generate the correct file as in my system it doesn't recognize service GreetService{} line as a service.

I am using the following version of protoc on windows system:

PS D:\Study\grpc\go-grpc-course> protoc --version
libprotoc 3.17.3

Using below command to generate the code:

protoc .\greet\greetpb\greet.proto --go_out=.

Below is the go code generated by above command:

// Code generated by protoc-gen-go. DO NOT EDIT.
// versions:
//  protoc-gen-go v1.26.0
//  protoc        v3.17.3
// source: greet/greetpb/greet.proto

package greetpb

import (
    protoreflect "google.golang.org/protobuf/reflect/protoreflect"
    protoimpl "google.golang.org/protobuf/runtime/protoimpl"
    reflect "reflect"
)

const (
    // Verify that this generated code is sufficiently up-to-date.
    _ = protoimpl.EnforceVersion(20 - protoimpl.MinVersion)
    // Verify that runtime/protoimpl is sufficiently up-to-date.
    _ = protoimpl.EnforceVersion(protoimpl.MaxVersion - 20)
)

var File_greet_greetpb_greet_proto protoreflect.FileDescriptor

var file_greet_greetpb_greet_proto_rawDesc = []byte{
    0x0a, 0x19, 0x67, 0x72, 0x65, 0x65, 0x74, 0x2f, 0x67, 0x72, 0x65, 0x65, 0x74, 0x70, 0x62, 0x2f,
    0x67, 0x72, 0x65, 0x65, 0x74, 0x2e, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x12, 0x05, 0x67, 0x72, 0x65,
    0x65, 0x74, 0x32, 0x0e, 0x0a, 0x0c, 0x47, 0x72, 0x65, 0x65, 0x74, 0x53, 0x65, 0x72, 0x76, 0x69,
    0x63, 0x65, 0x42, 0x11, 0x5a, 0x0f, 0x2e, 0x2f, 0x67, 0x72, 0x65, 0x65, 0x74, 0x2f, 0x67, 0x72,
    0x65, 0x65, 0x74, 0x70, 0x62, 0x62, 0x06, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x33,
}

var file_greet_greetpb_greet_proto_goTypes = []interface{}{}
var file_greet_greetpb_greet_proto_depIdxs = []int32{
    0, // [0:0] is the sub-list for method output_type
    0, // [0:0] is the sub-list for method input_type
    0, // [0:0] is the sub-list for extension type_name
    0, // [0:0] is the sub-list for extension extendee
    0, // [0:0] is the sub-list for field type_name
}

func init() { file_greet_greetpb_greet_proto_init() }
func file_greet_greetpb_greet_proto_init() {
    if File_greet_greetpb_greet_proto != nil {
        return
    }
    type x struct{}
    out := protoimpl.TypeBuilder{
        File: protoimpl.DescBuilder{
            GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
            RawDescriptor: file_greet_greetpb_greet_proto_rawDesc,
            NumEnums:      0,
            NumMessages:   0,
            NumExtensions: 0,
            NumServices:   1,
        },
        GoTypes:           file_greet_greetpb_greet_proto_goTypes,
        DependencyIndexes: file_greet_greetpb_greet_proto_depIdxs,
    }.Build()
    File_greet_greetpb_greet_proto = out.File
    file_greet_greetpb_greet_proto_rawDesc = nil
    file_greet_greetpb_greet_proto_goTypes = nil
    file_greet_greetpb_greet_proto_depIdxs = nil
}

There aren't any services created in the later go code. Am I doing something wrong or is this some proto issue. Any help is appreciated.

Answer 1

You seem to forgot to add the go-grpc_out argument when using protoc. This argument is for generating the gRPC code. Please try the following:

protoc greet.proto --go_out=. --go-grpc_out=.

This is also described in the gRPC quickstart - section "Regenerate gRPC code"