Service Internal Traffic Policy

    Service Internal Traffic Policy enables internal traffic restrictions to only route internal traffic to endpoints within the node the traffic originated from. The “internal” traffic here refers to traffic originated from Pods in the current cluster. This can help to reduce costs and improve performance.

    Note: For pods on nodes with no endpoints for a given Service, the Service behaves as if it has zero endpoints (for Pods on this node) even if the service does have endpoints on other nodes.

    The kube-proxy filters the endpoints it routes to based on the spec.internalTrafficPolicy setting. When it’s set to Local, only node local endpoints are considered. When it’s or missing, all endpoints are considered. When the feature gate ServiceInternalTrafficPolicy is enabled, spec.internalTrafficPolicy defaults to “Cluster”.

    • Service Internal Traffic Policy is not used when externalTrafficPolicy is set to on a Service. It is possible to use both features in the same cluster on different Services, just not on the same Service.