Port redirect with nginx

gistfile1.txt

# Nginx config for redirecting traffic from port 80 to 8800

upstream app {
    server localhost:8800 fail_timeout=60;
}

server {
    listen 80;
    client_max_body_size 100m;
    server_name app.example.com;

    keepalive_timeout 65;

    location / {
        proxy_pass        http://app;
        proxy_set_header  X-Real-IP  $remote_addr;
        proxy_set_header  Host $host;
    }
}