Check out Negroni middleware. It let's you pass your HTTP request through different middleware and custom HandlerFuncs.
Something like this:
n := negroni.New(
negroni.NewRecovery(),
negroni.HandlerFunc(myMiddleware),
negroni.NewLogger(),
negroni.NewStatic(http.Dir("public")),
)
...
...
func myMiddleware(rw http.ResponseWriter, r *http.Request, next http.HandlerFunc) {
log.Println("Logging on the way there...")
if r.URL.Query().Get("password") == "secret123" {
next(rw, r) //**<--------passing the request to next middleware/func**
} else {
http.Error(rw, "Not Authorized", 401)
}
log.Println("Logging on the way back...")
}
Notice how next(rw,r)
is used to pass along the HTTP request
If you don't want to use Negroni, you can always look at it's implementation on how it passes the HTTP request to another middleware.
It uses custom handler which looks something like:
handlerFunc func(rw http.ResponseWriter, r *http.Request, next http.HandlerFunc)
Ref: https://gobridge.gitbooks.io/building-web-apps-with-go/content/en/middleware/index.html