go-jwt-sample

package main

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

	jwtmiddleware "github.com/auth0/go-jwt-middleware"
	jwt "github.com/dgrijalva/jwt-go"
	"github.com/gorilla/mux"
)

type post struct {
	Title string `json:"title"`
}

var public = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
	post := &post{
		Title: "public",
	}
	json.NewEncoder(w).Encode(post)
})

var private = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
	post := &post{
		Title: "private",
	}
	json.NewEncoder(w).Encode(post)
})

const SIGNINGKEY = "SIGNINGKEY...."

var GetTokenHandler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {

	token := jwt.New(jwt.SigningMethodHS256)

	claims := token.Claims.(jwt.MapClaims)
	claims["admin"] = true
	claims["sub"] = "54546557354"
	claims["name"] = "taro"
	claims["iat"] = time.Now()
	claims["exp"] = time.Now().Add(time.Hour * 24).Unix()

	tokenString, _ := token.SignedString([]byte(SIGNINGKEY))
	w.Write([]byte(tokenString))
})

var JwtMiddleware = jwtmiddleware.New(
	jwtmiddleware.Options{
		ValidationKeyGetter: func(token *jwt.Token) (interface{}, error) {
			return []byte(SIGNINGKEY), nil
		},
		SigningMethod: jwt.SigningMethodHS256,
	},
)

func main() {
	r := mux.NewRouter()
	r.Handle("/public", public)
	r.Handle("/private", JwtMiddleware.Handler(private))
	r.Handle("/auth", GetTokenHandler)
	if err := http.ListenAndServe(":8080", r); err != nil {
		log.Fatal("ListenAndServe:", nil)
	}
}