Docker VPN / PPTP Client Implementation

Hi guys. I’m currently researching Docker and PPTP VPNs.

I have done some reading on how Docker handles networking, but can’t seem to find a solid resource on how it handles PPTP VPNs compared to a Host system like Linux. Many of the questions regarding PPTP connections here are for debugging existing implementations.

I was hoping this thread could serve as an entry point for myself and others to actually create our own VPN client implementations. Seeing as how PPTP is still in wide use I think this thread would be exceptionally useful for developers navigating this same use-case.

Here’s the high level question:

  • How does Docker actually connect to and route traffic over a PPTP VPN?

And a lower level detail question:

  • Does Docker route traffic from its entire network (default bridge, or otherwise) over this VPN, or only the specific container?

I’d love to see a holistic discussion on this problem. Thanks and hope we can get some input from experienced engineers.