Defining an interface definition language file

The gRPC service that we are developing is going to support the following functionality:

• The server should return its date and time to the client
• The server should return a randomly generated password of a given length to the client
• The server should return random integers to the client

Before we begin developing the gRPC client and server for our service, we need to define the IDL file. We need a separate GitHub repository to host the files related to the IDL file, which is going to be https://github.com/mactsouk/protoapi.

Next, we are going to present the IDL file, which is called protoapi.proto:

syntax = "proto3";

The presented file uses the proto3 version of the protocol buffers language—there is also an older version of the language named proto2, which has some minor syntax differences. If you do not specify that you want to use proto3, then the protocol buffer compiler...