Prerequisites:

1. Go plugins:

   1. $ go install google.golang.org/protobuf/cmd/protoc-gen-go@latest
   2. $ go install google.golang.org/grpc/cmd/protoc-gen-go-grpc@latest
   3. update path

   https://grpc.io/docs/languages/go/quickstart/#prerequisites

2. Protocol Buffer Compiler version 3

   1. follow instructions on https://grpc.io/docs/protoc-installation/ or https://github.com/protocolbuffers/protobuf/releases

Run Server:

$ go run greeter_server/main.go

Run Client:

$ go run greeter_client/main.go

CRUD Contracts:

1. update helloworld/helloworld.proto file
2. run $ protoc --go_out=. --go_opt=paths=source_relative --go-grpc_out=. --go-grpc_opt=paths=source_relative helloworld/helloworld.proto
3. implement your changes on server and client programs