I currently have two clusters on GKE - one in eu-west1-b and another in us-east1-b. The pods deployed to the nodes in these clusters need to make location-based requests (for latency testing purposes).

I also need to connect to my postgres instance on RDS, which uses IP-based whitelisting for external connections. The nodes in my clusters have ephemeral IPs so I can't use them.

I have done a lot of research and gone through lots of SO answers and docs and tutorials and come to the solution that routing traffic through a NAT is pretty much the best/only way to do this right now on GKE.

https://serverfault.com/questions/835425/kubernetes-external-connection-through-single-ip

Similar to that question above, I don't want to route all of my traffic through the NAT. My reason is because I need my requests to come from the internet gateway associated with the current node so it is coming from a particular region.

The above question has some answers that almost get me there, but doesn't include any kube-specific configuaration. This is a great tutorial:

https://docs.tenable.com/pvs/deployment/Content/GoogleCloudInstructionsNatGateway.htm

But again, is not based on kube.

My thinking is that I need to define a service for postgres in my kube cluster, and then tell that to route to the external service through the NAT. Not entirely sure where to start and would appreciate help.