Golang http.Handler类代码示例

// PlainText sets the content-type of responses to text/plain.
func Json(h http.Handler) http.Handler {
	fn := func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "text/json")
		h.ServeHTTP(w, r)
	}
	return http.HandlerFunc(fn)
}

func debugMiddleware(h http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		t0 := time.Now()
		h.ServeHTTP(w, r)

		if shouldDebugHTTP() {
			ms := 1000 * time.Since(t0).Seconds()

			// The variable `w` is most likely a *http.response, which we can't do
			// much with since it's a non exported type. We can however peek into
			// it with reflection to get at the status code and number of bytes
			// written.
			var status, written int64
			if rw := reflect.Indirect(reflect.ValueOf(w)); rw.IsValid() && rw.Kind() == reflect.Struct {
				if rf := rw.FieldByName("status"); rf.IsValid() && rf.Kind() == reflect.Int {
					status = rf.Int()
				}
				if rf := rw.FieldByName("written"); rf.IsValid() && rf.Kind() == reflect.Int64 {
					written = rf.Int()
				}
			}
			httpl.Debugf("http: %s %q: status %d, %d bytes in %.02f ms", r.Method, r.URL.String(), status, written, ms)
		}
	})
}

func withDetailsMiddleware(id protocol.DeviceID, h http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("X-Syncthing-Version", Version)
		w.Header().Set("X-Syncthing-ID", id.String())
		h.ServeHTTP(w, r)
	})
}

func wrapBasicAuth(handler http.Handler, credential string) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		token := strings.SplitN(r.Header.Get("Authorization"), " ", 2)

		if len(token) != 2 || strings.ToLower(token[0]) != "basic" {
			w.Header().Set("WWW-Authenticate", `Basic realm="GoTTY"`)
			http.Error(w, "Bad Request", http.StatusUnauthorized)
			return
		}

		payload, err := base64.StdEncoding.DecodeString(token[1])
		if err != nil {
			http.Error(w, "Internal Server Error", http.StatusInternalServerError)
			return
		}

		if credential != string(payload) {
			w.Header().Set("WWW-Authenticate", `Basic realm="GoTTY"`)
			http.Error(w, "authorization failed", http.StatusUnauthorized)
			return
		}

		log.Printf("Basic Authentication Succeeded: %s", r.RemoteAddr)
		handler.ServeHTTP(w, r)
	})
}

func Green(next http.Handler) http.Handler {
	return http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
		rw.Header().Set("X-Favorite-Color", "green")
		next.ServeHTTP(rw, req)
		fmt.Fprint(rw, " who likes green")
	})
}

func Logger(h http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		//startTime := time.Now()
		h.ServeHTTP(w, r)
		//log.Printf("[vertigo] %s %s (%v)\n", r.Method, r.URL.Path, time.Since(startTime))
	})
}

// ServeHTTP dispatches the handler registered in the matched route.
//
// When there is a match, the route variables can be retrieved calling
// mux.Vars(request).
func (r *Router) ServeHTTP(w http.ResponseWriter, req *http.Request) {
	// Clean path to canonical form and redirect.
	if p := cleanPath(req.URL.Path); p != req.URL.Path {

		// Added 3 lines (Philip Schlump) - It was dropping the query string and #whatever from query.
		// This matches with fix in go 1.2 r.c. 4 for same problem.  Go Issue:
		// http://code.google.com/p/go/issues/detail?id=5252
		url := *req.URL
		url.Path = p
		p = url.String()

		w.Header().Set("Location", p)
		w.WriteHeader(http.StatusMovedPermanently)
		return
	}
	var match RouteMatch
	var handler http.Handler
	if r.Match(req, &match) {
		handler = match.Handler
		setVars(req, match.Vars)
		setCurrentRoute(req, match.Route)
	}
	if handler == nil {
		handler = r.NotFoundHandler
		if handler == nil {
			handler = http.NotFoundHandler()
		}
	}
	if !r.KeepContext {
		defer context.Clear(req)
	}
	handler.ServeHTTP(w, req)
}

// cors responds to incoming requests and adds the appropriate cors headers
// TODO: corylanou: add the ability to configure this in our config
func cors(inner http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if origin := r.Header.Get("Origin"); origin != "" {
			w.Header().Set(`Access-Control-Allow-Origin`, origin)
			w.Header().Set(`Access-Control-Allow-Methods`, strings.Join([]string{
				`DELETE`,
				`GET`,
				`OPTIONS`,
				`POST`,
				`PUT`,
			}, ", "))

			w.Header().Set(`Access-Control-Allow-Headers`, strings.Join([]string{
				`Accept`,
				`Accept-Encoding`,
				`Authorization`,
				`Content-Length`,
				`Content-Type`,
				`X-CSRF-Token`,
				`X-HTTP-Method-Override`,
			}, ", "))
		}

		if r.Method == "OPTIONS" {
			return
		}

		inner.ServeHTTP(w, r)
	})
}

// Handle regiester a standard http.Handler request handler with the given
// path and method. With this adapter, your handler won't have access to the
// context and thus won't work with URL parameters.
func (mux *Mux) Handle(method, path string, handler http.Handler) {
	mux.HandleC(method, path,
		xhandler.HandlerFuncC(func(_ context.Context, w http.ResponseWriter, r *http.Request) {
			handler.ServeHTTP(w, r)
		}),
	)
}

func Log(handler http.Handler) http.Handler {
	log.Println(handler)
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		log.Printf("%s %s %s &s", r.RemoteAddr, r.Method, r.URL)
		handler.ServeHTTP(w, r)
	})
}

func auth(config *Config, next http.Handler) http.Handler {
	unauthorized := func(w http.ResponseWriter) {
		send(w, http.StatusUnauthorized, Json{"error": "Unauthorized"})
	}

	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
		if config.Auth != "" {
			s := strings.SplitN(req.Header.Get("Authorization"), " ", 2)
			if len(s) != 2 || s[0] != "Basic" {
				unauthorized(w)
				return
			}

			base, err := base64.StdEncoding.DecodeString(s[1])
			if err != nil {
				unauthorized(w)
				return
			}

			pair := strings.SplitN(string(base), ":", 2)
			if len(pair) != 2 {
				unauthorized(w)
				return
			}

			password := pair[1]
			if config.Auth != password {
				unauthorized(w)
				return
			}
		}

		next.ServeHTTP(w, req)
	})
}

func Wrap(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		m := New(w, r)
		next.ServeHTTP(m, r)
		m.Log()
	})
}

func (c *MasterConfig) authorizationFilter(handler http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
		attributes, err := c.AuthorizationAttributeBuilder.GetAttributes(req)
		if err != nil {
			forbidden(err.Error(), attributes, w, req)
			return
		}
		if attributes == nil {
			forbidden("No attributes", attributes, w, req)
			return
		}

		ctx, exists := c.RequestContextMapper.Get(req)
		if !exists {
			forbidden("context not found", attributes, w, req)
			return
		}

		allowed, reason, err := c.Authorizer.Authorize(ctx, attributes)
		if err != nil {
			forbidden(err.Error(), attributes, w, req)
			return
		}
		if !allowed {
			forbidden(reason, attributes, w, req)
			return
		}

		handler.ServeHTTP(w, req)
	})
}

// namespacingFilter adds a filter that adds the namespace of the request to the context.  Not all requests will have namespaces,
// but any that do will have the appropriate value added.
func namespacingFilter(handler http.Handler, contextMapper kapi.RequestContextMapper) http.Handler {
	infoResolver := &apiserver.RequestInfoResolver{APIPrefixes: sets.NewString("api", "osapi", "oapi", "apis"), GrouplessAPIPrefixes: sets.NewString("api", "osapi", "oapi")}

	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
		ctx, ok := contextMapper.Get(req)
		if !ok {
			http.Error(w, "Unable to find request context", http.StatusInternalServerError)
			return
		}

		if _, exists := kapi.NamespaceFrom(ctx); !exists {
			if requestInfo, err := infoResolver.GetRequestInfo(req); err == nil {
				// only set the namespace if the apiRequestInfo was resolved
				// keep in mind that GetAPIRequestInfo will fail on non-api requests, so don't fail the entire http request on that
				// kind of failure.

				// TODO reconsider special casing this.  Having the special case hereallow us to fully share the kube
				// APIRequestInfoResolver without any modification or customization.
				namespace := requestInfo.Namespace
				if (requestInfo.Resource == "projects") && (len(requestInfo.Name) > 0) {
					namespace = requestInfo.Name
				}

				ctx = kapi.WithNamespace(ctx, namespace)
				contextMapper.Update(req, ctx)
			}
		}

		handler.ServeHTTP(w, req)
	})
}

func Logger(inner http.Handler, name string) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		start := time.Now()
		w.Header().Add("Access-Control-Allow-Origin", "http://ayeke.me:3000")
		var err error
		defer func() {
			r := recover()
			if r != nil {
				switch t := r.(type) {
				case string:
					err = errors.New(t)
				case error:
					err = t
				default:
					err = errors.New("Unknown error")
				}
				http.Error(w, err.Error(), http.StatusInternalServerError)
			}
		}()
		inner.ServeHTTP(w, r)

		log.Printf(
			"%s\t%s\t%s\t%s",
			r.Method,
			r.RequestURI,
			name,
			time.Since(start),
		)
	})
}