brew install protobuf

go install google.golang.org/protobuf/cmd/[email protected]
go install google.golang.org/grpc/cmd/[email protected]

protoc --proto_path=proto --go_out=proto --go_opt=paths=source_relative --go-grpc_out=proto --go-grpc_opt=paths=source_relative proto/helloworld.proto

go run simple/server/server.go

go run simple/client/client.go