kubernetes/pkg/proxy/topology.go

// CategorizeEndpoints returns:
//
//   - The service's usable Cluster-traffic-policy endpoints (taking topology into account, if
//     relevant). This will be nil if the service does not ever use Cluster traffic policy.
//
//   - The service's usable Local-traffic-policy endpoints (including terminating endpoints, if
//     relevant). This will be nil if the service does not ever use Local traffic policy.
//
//   - The combined list of all endpoints reachable from this node (which is the union of the
//     previous two lists, but in the case where it is identical to one or the other, we avoid
//     allocating a separate list).
//
//   - An indication of whether the service has any endpoints reachable from anywhere in the
//     cluster. (This may be true even if allReachableEndpoints is empty.)
func CategorizeEndpoints(endpoints []Endpoint, svcInfo ServicePort, nodeLabels map[string]string) (clusterEndpoints, localEndpoints, allReachableEndpoints []Endpoint, hasAnyEndpoints bool) { … }

// canUseTopology returns true if topology aware routing is enabled and properly
// configured in this cluster. That is, it checks that:
//   - The TopologyAwareHints or ServiceTrafficDistribution feature is enabled.
//   - If ServiceTrafficDistribution feature gate is not enabled, then the
//     hintsAnnotation should represent an enabled value.
//   - The node's labels include "topology.kubernetes.io/zone".
//   - All of the endpoints for this Service have a topology hint.
//   - At least one endpoint for this Service is hinted for this node's zone.
func canUseTopology(endpoints []Endpoint, svcInfo ServicePort, nodeLabels map[string]string) bool { … }

// availableForTopology checks if this endpoint is available for use on this node, given
// topology constraints. (It assumes that canUseTopology() returned true.)
func availableForTopology(endpoint Endpoint, nodeLabels map[string]string) bool { … }

// filterEndpoints filters endpoints according to predicate
func filterEndpoints(endpoints []Endpoint, predicate func(Endpoint) bool) []Endpoint { … }