This is an overview of how to setup dns servers on mac osx with openvpn.  Only tested with tunnelblick openvpn client.

Have your user create:
```
~/Library/openvpn/connected.sh
~/Library/openvpn/post-disconnect.sh
```

Ensure these files are executable:
```
chmod +x ~/Library/openvpn/connected.sh
chmod +x ~/Library/openvpn/post-disconnect.sh
```

add this to your ovpn client config file
```
up ~/Library/openvpn/connected.sh
down ~/Library/openvpn/post-disconnect.sh
```

Have your user install the ovpn file and connect to your openvpn server (I won't go into detail here).

In the tunnelblick VPN Details log, you should see the following on successful connection:
"*Tunnelblick: The 'connected.sh' script executed successfully"

In the tunnelblick VPN Details log, you should see the following on successful disconnection:
"*Tunnelblick: The 'post-disconnect.sh' script executed successfully"

The user can verify dns servers by running (pre/during/post vpn connection):
```
cat /etc/resolv.conf
```