Golang Gorilla mux with http.FileServer returning 404

Question

The problem I\'m seeing is that I\'m trying to use the http.FileServer with the Gorilla mux Router.Handle function.

This doesn\'t work (the image return

Answer 1

As of May 2015 gorilla/mux package still have no version releases. But problem is different now. It is not that myRouter.Handle does not match url and needs regexp, it does! But http.FileServer requires prefix to be removed from url. Below example works fine.

ui := http.FileServer(http.Dir("ui"))
myRouter.Handle("/ui/", http.StripPrefix("/ui/", ui))

Note, there is no /ui/{rest} in abowe example. You may also wrap http.FileServer into logger gorilla/handler and see request to coming to FileServer and response 404 going out.

ui := handlers.CombinedLoggingHandler(os.Stderr,http.FileServer(http.Dir("ui"))
myRouter.Handle("/ui/", ui) // getting 404
// works with strip: myRouter.Handle("/ui/", http.StripPrefix("/ui/", ui))

Answer 2

I posted this on golang-nuts discussion group and got this solution from Toni Cárdenas ...

The standard net/http ServeMux (which is the standard handler you are using when you use http.Handle) and the mux Router have different ways of matching an address.

See the differences between http://golang.org/pkg/net/http/#ServeMux and http://godoc.org/github.com/gorilla/mux.

So basically, http.Handle('/images/', ...) matches '/images/whatever', while myRouter.Handle('/images/', ...) only matches '/images/', and if you want to handle '/images/whatever', you have to ...

Option 1 - Use a regular expression match in your router

myRouter.Handle("/images/{rest}",
     http.StripPrefix("/images/", http.FileServer(http.Dir(HomeFolder + "images/"))))

Option 2 - Use the PathPrefix method on your router:

myRouter.PathPrefix("/images/").Handler(http.StripPrefix("/images/", 
     http.FileServer(http.Dir(HomeFolder + "images/"))))