Go: How to use middleware pattern?

Question

I have a function that executes only with specific conditions (e.g. role == 'Administrator'). Now, I use 'if' statement. But it could be situations when number of conditions is high and 'if' with long definition looks not so esthetic.
Is it available mechanism in Go (or related with Go framework) allows implementation of middleware concept (action filters)?

For example, ASP.NET MVC allows to do this:

[MyFilter]
public ViewResult Index()
{
     // Filter will be applied to this specific action method
}

So, MyFilter() implemented in the separate class allows better code composition and testing.

Update: Revel (web framework for the Go) provides similar functionality with Interceptors (function that is invoked by the framework BEFORE or AFTER an action invocation): https://revel.github.io/manual/interceptors.html

Answer 1

Waitting for answers