HTTP Middleware

In a proper production environment you can integrate with different packages and HTTP routers. Gorilla MUX

A very basic middleware which timestamps the http request being handled could be written as:

func notaryMiddleware(next http.Handler) http.Handler {
    return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
        // Stamp & Notarize 
        _, err = sdk.stamp(ctx, sdk.message.FromHttpRequest(r)) 
        if err != nil {
            log.Println("could not stamp: %v", err)
        }
        // Call the next handler, which can be another middleware in the chain, or the final handler.
        next.ServeHTTP(w, r)
    })
}

Middlewares can be added to a router using Router.Use():

r := mux.NewRouter()
r.HandleFunc("/", handler)
r.Use(notaryMiddleware)