Stable public IP or IP range for outbound connections in GKE

Solution 1:

Google Cloud now provides a managed NAT Gateway service - Cloud NAT.

This gateway can be used with a GKE cluster, which provides a stable public egress IP to all the pods inside it, which enables them to be whitelisted by third party service providers.

The example implementation for using Cloud NAT with GKE is provided here - https://cloud.google.com/nat/docs/gke-example

Solution 2:

You can try this solution :

https://cloud.google.com/solutions/using-a-nat-gateway-with-kubernetes-engine

Under normal circumstances, Google Kubernetes Engine nodes route all egress traffic through the internet gateway associated with their node cluster. The internet gateway connection, in turn, is defined by the Compute Engine network associated with the node cluster. Each node in the cluster has an ephemeral external IP address. When nodes are created and destroyed during autoscaling, new node IP addresses are allocated automatically.

The default gateway behavior works well under normal circumstances. However, you might want to modify how ephemeral external IP addresses are allocated in order to:

• Provide a third-party service with a consistent external IP address.
• Monitor and filter egress traffic out of the Google Kubernetes Engine cluster.