We have a VPN tunnel from the office to the Google Cloud. It's working correctly, we are able to hit VMs and containers (kubernetes).
The problem is that the SQL instance can't be accessed using this tunnel. You can jump through a VM instance but you can't connect directly. Apparently the problem is that the SQL instances are not directly connected to a VPC subnet. We tried forcing the route on the "Cloud Router" for the VPC but that didn't work. We tried adding an "allow-all" firewall rule for all the VPC range, it wasn't that either.
Any idea on how to reach the SQL instances through the VPN tunnel?