Client for my gRPC server（ブログ公開用） https://nekonenene.hatenablog.com/entry/2019/02/17/073806

client02.go

package main

import (
	"context"
	"go/build"
	"log"
	"os"
	"strconv"
	"time"

	pb "nekonenene/hello/pb"

	"google.golang.org/grpc"
	"google.golang.org/grpc/credentials"
)

const (
	address     = "grpc-test.hatone.net:443"
	defaultName = "Kaname"
	defaultAge  = 20
)

func main() {
	certFile := build.Default.GOPATH + "/src/google.golang.org/grpc/roots.pem"
	creds, err := credentials.NewClientTLSFromFile(certFile, "")
	if err != nil {
		log.Fatalf("failed to generate credentials: %v", err)
	}

	conn, err := grpc.Dial(address, grpc.WithTransportCredentials(creds))
	if err != nil {
		log.Fatalf("did not connect: %v", err)
	}

	defer conn.Close()
	c := pb.NewGreeterClient(conn)

	name := defaultName
	age := defaultAge
	if len(os.Args) > 2 {
		name = os.Args[1]
		age, _ = strconv.Atoi(os.Args[2])
	}

	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
	defer cancel()

	r, err := c.SayHello(ctx, &pb.HelloRequest{Name: name, Age: int32(age)})
	if err != nil {
		log.Fatalf("could not get message: %v", err)
	}

	log.Printf("Got message: %s", r.Message)
}