Golang http middleware implementation in 7 LOC

// middleware - a type that describes a middleware, at the core of this 
// implementation a middleware is merely a function that takes a handler
// function, and returns a handler function.
type middleware func(http.HandlerFunc) http.HandlerFunc

// buildChain - a function that takes a handler function, a list of middlewares
// and creates a new application stack as a single http handler
func buildChain(f http.HandlerFunc, m ...middleware) http.HandlerFunc {
    // if there are no more middlewares, we just return the 
    // handlerfunc, as we are done recursing.
	if len(m) == 0 {
		return f
	}
    // otherwise pop the middleware from the list,
    // and call build chain recursively as it's parameter
	return m[0](buildChain(f, m[1:cap(m)]...))
}

// ... later in the code when we are setting up the router

	// set up awesome router ;)
	router := vestigo.NewRouter()
	router.Get("/v:version/private", buildChain(f, 
        RecoveryMiddleware,
        LoggingMiddleware,
        AuthenticationMiddleware,
        //...
    ))

// ... later in code when defining a middleware

// AuthMiddleware - takes in a http.HandlerFunc, and returns a http.HandlerFunc
var AuthMiddleware = func(f http.HandlerFunc) http.HandlerFunc {
	// one time scope setup area for middleware
	return func(w http.ResponseWriter, r *http.Request) {
		// ... pre handler functionality
		fmt.Println("start auth")
		f(w, r)
		fmt.Println("end auth")
		// ... post handler functionality
	}
}