javascript/Vue.js app behind Traefik v2.0

Thanks this helped me figuring out how to serve dev server while behind traefik.
One think though. the following label settings where transparent:

labels:
      - "traefik.enable=true"
      - "traefik.http.routers.frontend.rule=Host(`frontend.service.localhost`)"
      - "traefik.docker.network=traefik"

I had to add the rule with loadbalancer service and also create a vue.config.js file (at the same level as the package.json file) with the following content:

module.exports = {
    devServer: {
        public: 'frontend.service.localhost',
        port: 80,
        compress: true,
    }
}

Maybe there is way to do it without the vue.config.js file. if so that would be great, since I don't won't to have that suff configured in the app