I read the Drone documentation and learn that Drone does not really do CVS polling. It is only trigger by a web hook created by git events. This is pretty much a show stopper for Drone deployments in private network environments.
To work around this limitation, I created a small utility to spawn a web hook proxy for Drone in the cloud and uses a local web hook agent to poll that proxy before delivering messages to the local Drone instance.
The source code and documentation and available at https://github.com/imulab-x/drone-webhook-proxy
Suggestions and feedbacks are appreciated.