Only add iptables rules if they don't already exist

roles/vpn/templates/rc.local_ansible_openvpn

 # This script should be included in your rc.local
 #
 
+iptables -C FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT || \
 iptables -A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT
+iptables -C FORWARD -s 10.8.0.0/24 -j ACCEPT || \
 iptables -A FORWARD -s 10.8.0.0/24 -j ACCEPT
+iptables -C FORWARD -j REJECT || \
 iptables -A FORWARD -j REJECT
+iptables -t nat -C POSTROUTING -s 10.8.0.0/24 -o {{ ansible_default_ipv4.interface }} -j MASQUERADE || \
 iptables -t nat -A POSTROUTING -s 10.8.0.0/24 -o {{ ansible_default_ipv4.interface }} -j MASQUERADE
 
 systemctl restart dnsmasq