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

Former-commit-id: 0cb5121e7d44644f7f0eb34597ff34274157fe95

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

@@ -0,0 +1,50 @@
+package main
+
+import (
+	"bytes"
+	"crypto/tls"
+	"crypto/x509"
+	"encoding/json"
+	"io/ioutil"
+	"log"
+	"net/http"
+
+	pb "github.com/kataras/iris/v12/_examples/mvc/grpc-compatible/helloworld"
+)
+
+func main() {
+	b, err := ioutil.ReadFile("../server.crt")
+	if err != nil {
+		log.Fatal(err)
+	}
+	cp := x509.NewCertPool()
+	if !cp.AppendCertsFromPEM(b) {
+		log.Fatal("credentials: failed to append certificates")
+	}
+
+	transport := &http.Transport{
+		TLSClientConfig: &tls.Config{
+			RootCAs: cp,
+		},
+	}
+
+	client := http.Client{Transport: transport}
+	buf := new(bytes.Buffer)
+	err = json.NewEncoder(buf).Encode(pb.HelloRequest{Name: "world"})
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	resp, err := client.Post("https://localhost/hello", "application/json", buf)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer resp.Body.Close()
+
+	var reply pb.HelloReply
+	err = json.NewDecoder(resp.Body).Decode(&reply)
+	if err != nil {
+		log.Fatal(err)
+	}
+	log.Printf("Greeting: %s", reply.GetMessage())
+}