I have recently started using Google Cloud Platform. I am looking into making a vpn service with it. I have created an obfuscated OpenVPN server with it running on port 443. The only problem I have with that is the egress data usage. I have given it to a friend to test for now as I am operating on the free credit. I am wondering if there is a way to track data usage to a specific ip so I know that it is not somebody other than the two of us. Thank you for all of your help!
If the two peers authenticate themselves properly, then there is no risk of being hacked in a way. Note that there are some requirements from Google side, to establish VPN tunnel, that need to be met.
You still can check that information in your Console, under Logging, selecting Cloud VPN Gateway.