add a full gRPC example as previously requested at: https://github.com/kataras/iris/issues/1449

Former-commit-id: 0cb5121e7d44644f7f0eb34597ff34274157fe95

_examples/mvc/grpc-compatible/grpc-client/main.go

@@ -0,0 +1,47 @@
+// Package main implements a client for Greeter service.
+package main
+
+import (
+	"context"
+	"log"
+	"os"
+	"time"
+
+	pb "github.com/kataras/iris/v12/_examples/mvc/grpc-compatible/helloworld"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials"
+)
+
+const (
+	address     = "localhost:443"
+	defaultName = "world"
+)
+
+func main() {
+	// Set up a connection to the server.
+	cred, err := credentials.NewClientTLSFromFile("../server.crt", "localhost")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	conn, err := grpc.Dial(address, grpc.WithTransportCredentials(cred), grpc.WithBlock())
+	if err != nil {
+		log.Fatalf("did not connect: %v", err)
+	}
+	defer conn.Close()
+	c := pb.NewGreeterClient(conn)
+
+	// Contact the server and print out its response.
+	name := defaultName
+	if len(os.Args) > 1 {
+		name = os.Args[1]
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+	defer cancel()
+	r, err := c.PostHello(ctx, &pb.HelloRequest{Name: name})
+	if err != nil {
+		log.Fatalf("could not greet: %v", err)
+	}
+	log.Printf("Greeting: %s", r.GetMessage())
+}