I have a node in cloud environment which is used now as nginx and mongrels behind it.
This is what nginx config looks like:
upstream mongrel {
    server 127.0.0.1:8000;
    server 127.0.0.1:8001;
    server 127.0.0.1:8002;
}
I want to achieve the following:
- add another node
 - nginx has to know about this new node automatically without stopping him, changing config(manually adding new node's mongrels) and starting it again.
 
How can I make my load balancer(nginx) work in the way so it can be self-aware of nodes in cloud?