将中间件与Golang Gorilla Mux子路由器一起使用

Question

How can I apply middleware to a Go Gorilla Toolkit mux subrouter?

I have the following code:

router := mux.NewRouter().StrictSlash(true)
apiRouter := router.PathPrefix("/api/").Subrouter()

apiRouter.Methods(http.MethodGet).
    Path("/api/path/to/handler").Handler(handleAPICall)

I want to apply a middleware handler that checks a security token, but only on those paths that start with /api.

Answer 1

The following seems to work:

apiRouter := mux.NewRouter()

router.PathPrefix("/api/").Handler(http.StripPrefix("/api",
    adapt(apiRouter, checkTokenHandler)))

apiRouter.Methods(http.MethodGet).
    Path("/path/to/handler").Handler(handleAPICall)
// Note that `/api` has been removed from the path.

where

func adapt(h http.Handler, adapters ...func(http.Handler) http.Handler)
    http.Handler {
    for _, adapter := range adapters {
        h = adapter(h)
    }
    return h
}

and

func checkTokenHandler(h http.Handler) http.Handler {
    return http.HandlerFunc(func(res http.ResponseWriter, req *http.Request) {
        // Check the security cookie.
        h.ServeHTTP(res, req)
    })
}