I installed MEAN stack on Google Cloud. I created express project. Now I have public access to express app only with tunneling to 127.0.0.1:3000 (Link to article about accessing express). I want to access to express app from my Google Cloud public ip on port 80. Now I have Apache app on that port (80). How can I do that? Of course I want access to public dir only of express app not entire express app (security reasons).
We have a guide for setting up NodeJS applications in the way you want, you can take a look at it here.
As you can see, you would need to create a reverse proxy (with ProxyPass and ProxyPassReverse).
Let us know if you have any question.