gRPC - Import "google/api/annotations.proto" was not found or had errors

Question

After running protoc command I'm getting below error.

---

google/protobuf/descriptor.proto: File not found.

google/api/annotations.proto: Import "google/protobuf/descriptor.proto" was not found or had errors. google/api/annotations.proto:28:8: "google.protobuf.MethodOptions" is not defined. currency.proto: Import "google/api/annotations.proto" was not found or had errors.

My protoc version is - libprotoc 3.0.0

Here is my proto file code..

syntax = "proto3";

import "google/api/annotations.proto";

service Currency {
    // GetRate returns the exchange rate for the two provided currency codes 
    rpc GetRate(RateRequest) returns (RateResponse) {
        option (google.api.http) = {
            post: "/v1/convert",
            body:"*"
        };
    };
} 
....
....

My directory structure is..

I'm running below command - protoc -I proto/ proto/*.proto --go_out=plugins=grpc:pb

It works fine if I remove the import of google/api/annotations.proto and option... but when I import the google/api/annotations.proto and compile it using protoc, it gives me error.

Answer 1

annotations.proto is defined in google/api in Google's Google APIs repo.

You'll need to clone that repo/folder and then add it to the --proto_path to protoc compile the proto:

git clone git@github.com:googleapis/googleapis.git

protoc \
--proto_path=proto/ \
--proto_path=googleapis \
--go_out=plugins=grpc:pb \
proto/*.proto