Golang route groups with http.Mux

server.go

...............................
	mux := http.NewServeMux()
	mux.Handle("/healthz", server.healthCheckHandler())
	mux.Handle("/metrics", server.metrics.GetHandler())

    middlewares := []func(http.Handler) http.Handler{
        server.checkAuth,
        server.handlePost,
        server.logRequest,
        server.recoverPanic,
        server.timeoutHandler,
    }
	groupMux := newGroup(mux, "/api/v1/", middlewares...)
	groupMux.Handle("/getPosts", server.getPostsHandler())

	server.server = &http.Server{
		Handler:           mux,
		ReadHeaderTimeout: readHeaderTimeout,
	}

	// continue init
}


func newGroup(mux *http.ServeMux, pattern string, middlewares ...func(http.Handler) http.Handler) *http.ServeMux {
	grGroup := http.NewServeMux()

	subPattern := strings.TrimSuffix(pattern, "/")
	handler := http.StripPrefix(subPattern, grGroup)

	for _, middleware := range middlewares {
		handler = middleware(handler)
	}

	mux.Handle(pattern, handler)

	return grGroup
}