Running port 8080 but accessing through port 80

I run CherryPy on port 8080 with no root privilege. On the server, I also need to support access to port 80.

Thus, I create a file named under /etc/network/if-up.d.

# cat > /etc/network/if-up.d/system-iptables
#!/bin/sh
if [ $METHOD = "loopback" ]; then
  iptables -t nat -A PREROUTING -p tcp --dport 80 -j REDIRECT --to-port 8080
fi
^D
# chmod +x /etc/network/if-up.d/system-iptables