gogo/protobuf is the library to store some extensions from golang/protobuf in this repository. There are some useful packages that golang/protobuf does not provide. For instance,

1. Custom tags

Getting Started

In this example, protoc-gen-gogo is used but there are other binaries. To install it, you have to run:

go get -u github.com/gogo/protobuf/protoc-gen-gogo

Use custom tags for protobuf

As of Nov. 2019, adding custom tags for generated proto messages are under discussion in golang/protobuf. This comment is the formal proposal for it. Until it’s released, gogo/protobuf can be used for such a purpose. The example is like below, which is stored here

syntax = "proto2";

package tags;

import "github.com/gogo/protobuf/gogoproto/gogo.proto";

option (gogoproto.populate_all) = true;

message Outside {
	optional Inside Inside = 1 [(gogoproto.embed) = true, (gogoproto.jsontag) = ""];
	optional string Field2 = 2 [(gogoproto.jsontag) = "MyField2", (gogoproto.moretags) = "xml:\",comment\""];
	oneof filed {
		string Field3 = 3 [(gogoproto.jsontag) = "MyField3", (gogoproto.moretags) = "xml:\",comment\""];
	}
}

message Inside {
	optional string Field1 = 1 [(gogoproto.jsontag) = "MyField1", (gogoproto.moretags) = "xml:\",chardata\""];
}

You can generate golang files for the above proto file from proto to gen directory by:

> protoc --gogo_out gen -I ./proto -I $GOPATH/src proto/*.proto