使用dep时，如何正确为协议添加golang protobuf / ptypes？

Question

I'm having trouble including the google/protobuf/timestamp.proto well known type, when using dep.

I get an error: google/protobuf/timestamp.proto: File not found

service.proto:

syntax = "proto3";
import "google/protobuf/timestamp.proto";

package com.rynop.platform;
option go_package = "rpc";

service PlatformService {
  rpc Test(EmptyMessage) returns (EmptyMessage);
}

message EmptyMessage { }

message A {  
    string summary = 1;
    google.protobuf.Timestamp start = 2;
}

message B {
  repeated A foos = 1;
}

Install package containing timestamp .proto def:

dep ensure -add github.com/golang/protobuf/ptypes/timestamp 

Run protoc and get error:

build/bin/protoc -Ivendor -I. --twirp_typescript_out=version=v6:./clients/ts-json/ rpc/service.proto
google/protobuf/timestamp.proto: File not found.

The dir containing timestamp's .proto definition exists:

file vendor/github.com/golang/protobuf/ptypes/timestamp/timestamp.proto
vendor/github.com/golang/protobuf/ptypes/timestamp/timestamp.proto: ASCII text

I'm installing protoc locally because I wan't to lock-in/tie a protoc version to this project:

# fetch the protoc compiler
OS_NAME=$(shell uname -s)
ifeq ($(OS_NAME),Darwin)
    PROTOC_URL=https://github.com/google/protobuf/releases/download/v3.7.1/protoc-3.7.1-osx-x86_64.zip
endif
ifeq ($(OS_NAME),Linux)
    PROTOC_URL=https://github.com/google/protobuf/releases/download/v3.7.1/protoc-3.7.1-linux-x86_64.zip
endif
build/protoc build/bin/protoc:
    mkdir -p build/protoc/bin build/bin
    cd build/protoc && curl -L -o protoc.zip $(PROTOC_URL) && \
        unzip protoc.zip && mv bin/protoc ../bin/protoc

What am I doing wrong?

Answer 1

The protoc error you are getting relates to your INCLUDE path.

When you installed the protoc compiler (e.g. to /usr/local/bin/protoc), for it to pick up google's standard proto definitions like timestamp.proto - these need to be added somewhere along your INCLUDE path (on MacOS/Linux one may use /usr/local/include). Note: the protoc headers should have been included with the protoc compiler.

So your proto import file would typically be located here:

/usr/local/include/google/protobuf/timestamp.proto

This path will be referenced when the protoc compiler sees an import like:

import "google/protobuf/timestamp.proto";

So check your INCLUDE path and ensure the protoc headers are installed correctly.