This is the configuration for node-2 of VPN proxy implementation with google cloud.
For apps running on non standard 443 port we can use.
In this example we will redirect from port 443 to port 8006.
/sbin/iptables -F
/sbin/iptables -t nat -F
/sbin/iptables -t nat -A PREROUTING -p tcp --dport 443 -j REDIRECT --to-ports 8006