Limitations

• Minimum Kubernetes API server version: v1.21

• Referencing the same hybrid NEGs from multiple different Kubernetes Services is not supported. The controller does not prevent you from doing this, but behavior is undefined.

This means that NEG names that you provide in the solutions.cloud.google.com/hybrid-neg Kubernetes Service annotations must be unique across all Services in a Kubernetes cluster, and also across all Kubernetes clusters where k8s-hybrid-neg-controller is deployed and configured to use the same Google Cloud project ID and Compute Engine zones.

• Hybrid NEGs currently allow endpoints with IPv4 addresses only. If your Kubernetes Services are available via both IPv4 and IPv6 (dual stack networking), k8s-hybrid-neg-controller only adds the IPv4 endpoint addresses to the hybrid NEGs.

For details on IPv6 and dual-stack support by proxy load balancers on Google Cloud, see IPv6 for Application Load Balancers and proxy Network Load Balancers.

• You cannot use the network endpoint groups (NEGs) created by k8s-hybrid-neg-controller as backends of load balancers managed by the GKE Gateway controller using the Kubernetes Gateway API.

This is because the GKE Gateway controller manages the Cloud Load Balancing resources, such as network endpoint groups (NEGs) and backend services, created for the Kubernetes Services referenced by the Route resources of the Kubernetes Gateway API.