OpenVPN

start here https://github.com/salt-formulas/salt-formula-openvpn/

Routing all traffic through server:

iptables -I FORWARD -i tun0 -o eth0 \
         -s 10.0.8.0/24 -m conntrack --ctstate NEW -j ACCEPT

iptables -I FORWARD -m conntrack --ctstate RELATED,ESTABLISHED \
         -j ACCEPT

iptables -t nat -I POSTROUTING -o eth0 \
          -s 10.0.8.0/24 -j MASQUERADE