kube-prometheus/docs/endpoints-migration.md

Migration from Endpoints to EndpointSlice

kube-prometheus 0.17+ automatically configures Prometheus to use EndpointSlice instead of Endpoints for Kubernetes service discovery (Endpoints have been deprecated in Kubernetes 1.33).

While the migration should be seamless for "regular" pods, it requires a few manual steps for components running as host services (e.g. node_exporter and kubelet):

1. The node_exporter and kubelet ServiceMonitors rely on the Prometheus operator's kubelet controller which manages the kube-system/kubelet Service.
2. With kube-prometheus 0.17, the Prometheus operator starts with both --kubelet-endpoints=true and --kubelet-endpointslice=true to ensure that a) the operator synchronizes the EndpointSlice object(s) backing the kube-system/kubelet Service and b) Kubernetes stops mirroring the kube-system/kubelet Endpoints object to EndpointSlice object(s) (otherwise the operator and kube-controller-manager would fight for the same resources).
3. After verifying that all targets are correctly discovered, it is ok to modify the operator's deployment and use --kubelet-endpoints=false instead. This will become the default in a future version of kube-prometheus.
4. The kube-system/kubelet Endpoints object should be removed manually.

To verify the status of the Endpoints and EndpointSlice objects, run:

kubectl get -n kube-system endpoints kubelet
kubectl get -n kube-system endpointslice -l endpointslice.kubernetes.io/managed-by=prometheus-operator