Generate Protobuf messages from given go structs. No RPC, not gogo syntax, just pure Protobuf messages.
GO111MODULE=off go get -u github.com/anjmao/go2proto
go2proto -f ${PWD}/example/out -p github.com/anjmao/go2proto/example/in
Generated code may not be perfect but since it just 180 lines of code you are free to adapt it for your needs.