https_and_wss.go

/*
A HTTP*S* server.
The path /ws is special, dedicated for WebSocket connection.
The other paths work as ordinary (non-WebSocket) resource.
*/

package main

import (
	"crypto/tls"
	"encoding/json"
	"log"
	"net/http"
	"time"

	"github.com/gorilla/websocket"
)

type Response struct {
	Time time.Time `json:"time"`
	URL  string    `json:"url"`
}

var upgrader = websocket.Upgrader{
	ReadBufferSize:  4096,
	WriteBufferSize: 4096,
}

func main() {
	cert, err := tls.LoadX509KeyPair("ca.crt", "ca.key")
	if err != nil {
		log.Fatalf("tls.LoadX509KeyPair: %v\n", err)
	}

	conf := tls.Config{Certificates: []tls.Certificate{cert}}

	listener, err := tls.Listen("tcp", ":8443", &conf)
	if err != nil {
		log.Fatalf("tls.Listen: %v\n", err)
	}

	mux := http.NewServeMux()
	mux.HandleFunc("/", handleRoot)
	mux.HandleFunc("/ws", handleWs)

	err = http.Serve(listener, mux)
	if err != nil {
		log.Fatalf("http.Serve: %v\n", err)
	}

	log.Println("OK")
}

func handleRoot(w http.ResponseWriter, r *http.Request) {
	res := Response{
		Time: time.Now(),
		URL:  r.URL.Path,
	}
	data, err := json.Marshal(res)
	if err != nil {
		w.WriteHeader(http.StatusInternalServerError)
	} else {
		w.Header().Set("content-type", "application/json")
		w.Write(data)
	}
}

func handleWs(w http.ResponseWriter, r *http.Request) {
	conn, err := upgrader.Upgrade(w, r, nil)
	if err != nil {
		return
	}
	res := Response{
		Time: time.Now(),
		URL:  r.URL.Path,
	}
	err = conn.WriteJSON(&res)
	if err != nil {
		log.Fatalf("conn.WriteJSON: %v\n", err)
	}
	err = conn.Close()
	if err != nil {
		log.Fatalf("conn.Close: %v\n", err)
	}
}