Gorilla middleware authentication for specific routes not working

Im writing a http router for a API and some routes require authentication while some dont.

I dont want to ask for authentication on every route, so I split them up.

But theres a problem:

POST /account <-- This is a account registration endpoint, and does not require authentication

DELETE /account <-- This does require authentication to delete the current account

I have no idea how to seperate these properly, also my current attempt at making the middleware different for the two is failing:

package httpServer

import (
	"log"
	"net/http"
	"httpServer/handlers"
	"httpServer/middlewares"

	"github.com/gorilla/mux"
	"github.com/justinas/alice"
)

func Init() {
	log.Println("Initializing http routes...")

	defaultmiddlewares := alice.New(middlewares.Logger, middlewares.Recover)
	authmiddlewares := alice.New(middlewares.Authenticator)

	var mainRouter = mux.NewRouter()
	var authRouter = mux.NewRouter()

	// No auth required to call this
	mainRouter.HandleFunc("/health", handlers.HealthGet).Methods("GET")        // Get API health

    // authrouter should be a extension of main router (i think)
    mainRouter.Handle("/", authmiddlewares.Then(authRouter))

    // Authentication is not required for this
	mainRouter.HandleFunc("/account", handlers.AccountPost).Methods("POST")                    // Create an account

    // Authentication is required for this
	authRouter.HandleFunc("/account", handlers.AccountDelete).Methods("DELETE")                // Delete my account

    // WebSocket endpoint:
	authRouter.HandleFunc("/ws", handlers.UpgradeWs)
	authRouter.HandleFunc("/ws/", handlers.UpgradeWs) // If i dont add this it doesnt work??
    
    // Register mainRouter
	http.Handle("/", defaultmiddlewares.Then(mainRouter))
}

Calls to GET /health are just fine:
But calls to DELETE /account are failing with a 404 Not Found:

(Also near the end of the Init() function i register a websocket endpoint, for some reason if i dont register both those endpoints it fails to connect?)

You initialised two routers mainRouter and authRouter and only start mainRouter. DELETE /account is bound to authRouter . That is not started and listening. That is why 404 coming.

And you can write custom middleware implementations to gorilla/mux Middleware interface and use with gorilla/mux router. Example code is like below

func Init() {
log.Println("Initializing http routes...")
r := mux.NewRouter()
middleware := Middleware{
// inject any dependency if you need
}
r.Use(middleware.MiddlewareFunc)
// No auth required to call this
r.HandleFunc("/health", handlers.HealthGet).Methods("GET")        // Get API health
// authrouter should be a extension of main router (i think)
r.Handle("/", authmiddlewares.Then(authRouter))
// Authentication is not required for this
r.HandleFunc("/account", handlers.AccountPost).Methods("POST")                    // Create an account
// Authentication is required for this
r.HandleFunc("/account", handlers.AccountDelete).Methods("DELETE")                // Delete my account
http.ListenAndServe(":8080", r)
}
// Middleware your custom middleware implementation
type Middleware struct {}
func (m Middleware) MiddlewareFunc(handler http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
// you can check request method and paths and you can do authentications here
//eg := method = DELETE and path = /account, do authentication
handler.ServeHTTP(w, r)
})
}