title: Create a lightweight openvpn client on Android (server config already)
body: <p>I have a server which I install openvpn.
  I have config some client and now I want to create an openvpn client to connect to it with the client config I've created.</p>
  
  <p>I know there is an OpenVpn client on the market.
  But, how can I do my own client with the VPN API (VpnService, ...)
  Because I want to provide the client config with the app, so the client will just connect the android system</p>