I am trying to restrict access to my express/nodejs app so that it can only be accessed from it's domain url. Currently if I go to http://ip-address-of-server:3000, the app gets served directly, bypassing nginx.
I have tried adding 'localhost' in the app.listen --
app.listen(4000, 'localhost' , () => console.log('Server running'));
but this ends up making the app completely inaccessible. Even through nginx.
The app is running inside a docker container. And nginx is running on the host. I think this might be causing it but don't know how to fix this.
You can use Docker host mode networking for your app since you mentioned that "The app is running inside a docker container. And nginx is running on the host.".
Ref - https://docs.docker.com/network/host/
This way, it will be reachable via nginx on the same network. Your "localhost" settings will start working as usual after launching the container in docker host mode networking.