nginx reverse proxy multiple backends

Question

Here is my situation: I will have one frontend server running nginx, and multiple backends servers running apache + passenger with different rails applications. I am NOT try

Answer 1

@mohamnag's comment is right. proxy_pass is only allowed inside a location

See:

http://wiki.nginx.org/HttpProxyModule#proxy_pass

https://www.nginx.com/resources/admin-guide/reverse-proxy/

So the correct config would be

server { 
    server_name client.domain.com;

    location / {
        # app1 reverse proxy follow
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header Host $host;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_pass http://x.x.x.100:80;
    }
}

server { 
    server_name client2.domain.com;

    location / {
        # app2 reverse proxy settings follow
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header Host $host;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_pass http://x.x.x.101:80;
    }
}