add some info about the types/signatures in route middlewares

httpserver/routes.go

@@ -13,10 +13,15 @@ func (s *server) routes() {
 
 	// if you want to use a general purpose middleware (http.Handler
 	// wrapper) on a specific HandleFunc route, you need to take the
-	// .ServeHTTP of the http.Handler to get a HandleFunc, viz:
+	// .ServeHTTP of the http.Handler to get its HandleFunc, viz:
 	s.router.HandleFunc("/login", authMiddleware(s.handleLogin()).ServeHTTP).Methods("GET")
 
 	s.router.HandleFunc("/.well-known/healthcheck.json", s.handleHealthCheck()).Methods("GET")
 
+	// the Gorilla mux .Use() takes a http.Handler wrapper func, like
+	// most things that deal with "middlewares" like alice et c, and
+	// will call ServeHTTP on it.  These middlewares applied by the mux
+	// (you can .Use() more than one) will be applied to every request
+	// into the service.
 	s.router.Use(s.LoggingMiddleware())
 }