golang http middleware实现

青旅半醒 2022-05-21 01:26 182阅读 0赞

# golang http middleware实现 #

在登录后，可以使用中间件在处理业务逻辑前，先进行验证.

[自定义middleware参考][middleware]

func AuthOn(hFunc func(http.ResponseWriter, *http.Request)) func(http.ResponseWriter, *http.Request) {
        return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
            log.Printf("AuthOn %v, token %v\n", r.URL.Path, r.Header)
            hFunc(w, r)
        })
    }
    
    // in func main
    http.HandleFunc("/itemlist", AuthOn(getItemHandler))

关联jwt验证middleware, 携带的`token`只能放到header中; 如果放到body中，会影响正常的handler代码读取body中的字段．

func VerifyJWT(tokenString string) (jwt.MapClaims, error) {
    
        token, err := jwt.Parse(tokenString, func(token *jwt.Token) (interface{}, error) {
            // Don't forget to validate the alg is what you expect:
            if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
                return nil, fmt.Errorf("Unexpected signing method: %v", token.Header["alg"])
            }
    
            // hmacSampleSecret is a []byte containing your secret, e.g. []byte("my_secret_key")
            return hmacSampleSecret, nil
        })
    
        if claims, ok := token.Claims.(jwt.MapClaims); ok && token.Valid {
            log.Println(claims["openid"], claims["exp"])
            return claims, nil
        }
    
        log.Println(err)
        return nil, err
    }
    
    func AuthOn(hFunc func(http.ResponseWriter, *http.Request)) func(http.ResponseWriter, *http.Request) {
        return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
            token := r.Header.Get("token")
    
            log.Printf("AuthOn %v %v\n", r.URL.Path, token)
            if c, err := VerifyJWT(token); err == nil {
                da := c["devarea"]
                r.Header.Add("devarea", da.(string))
    
                hFunc(w, r)
            } else {
                log.Printf("AuthOn failed", err)
            }
        })
    }

[middleware]: https://www.alexedwards.net/blog/making-and-using-middleware