Proto files using google.protobuf imports - causing issues in NodeJS - node.js

Question

I have google.profobuf.* imports in a proto file (used by GRPC server written in go). When the same proto file is used to implement a GRPC client in NodeJS - I run into issues.
Details:
proto file used by the GRPC server (written in go):
tech.proto
syntax = "proto3";
package api;
import "google/protobuf/duration.proto";
import "google/protobuf/empty.proto";
message Info {
string desc = 1;
google.protobuf.Duration ttl = 2;
}
service Tech {
rpc BasicInfo(google.protobuf.Empty) returns (Info) {}
}
When this is used by the GRPC client written in NodeJs:
getTechInfo.js (first few lines)
'use strict';
const PROTO_PATH = __dirname + '/../../api/tech.proto';
const grpc = require('grpc');
const apiProto = grpc.load(PROTO_PATH).api;
I get the following error:
/Users/././node_modules/protobufjs/dist/protobuf.js:4720
throw Error("failed to import '"+importFilename+"' in '"+filename+"': file not found");
^
Error: failed to import '/Users/././api/google/protobuf/duration.proto' in '/Users/././api/register.proto': file not found
at Builder.ProtoBuf.Builder.BuilderPrototype.import (/Users/././node_modules/protobufjs/dist/protobuf.js:4720:35)
at Object.ProtoBuf.loadJson (/Users/././node_modules/protobufjs/dist/protobuf.js:5225:26)
at Object.ProtoBuf.loadProto (/Users/././node_modules/protobufjs/dist/protobuf.js:5128:25)
at Object.ProtoBuf.loadProtoFile (/Users/././node_modules/protobufjs/dist/protobuf.js:5174:52)
at Object.load (/Users/././node_modules/grpc/index.js:135:26)
at Object.<anonymous> (/Users/././src/api/getTechInfo.js:5:23)
at Module._compile (module.js:643:30)
at Object.Module._extensions..js (module.js:654:10)
at Module.load (module.js:556:32)
at tryModuleLoad (module.js:499:12)
The issue is with the imports in the proto file:
import "google/protobuf/duration.proto";
import "google/protobuf/empty.proto";
What is the recommended method to resolve these imports? Thanks in advance.
Using:
Node v8.9.4
"google-protobuf": "^3.5.0",
"grpc": "^1.10.1",

Answer 1

This is a known issue with the gRPC library, documented primarily in this issue. The grpc.load API does not support easily loading google/protobuf/*.proto files.
The simplest solution is to use the #grpc/proto-loader library, which automatically includes google/protobuf/*.proto files when loading proto files.
One alternative solution is to use grpc-tools to pre-generate files that can be used with the google-protobuf library.