I have a k8s cluster deployed in openstack. I have deployed Prometheus operator for it to monitor the cluster. But I am getting Kube Scheduler & Etcd Targets Down alert.

I would like to know how Prometheus operator scrapes Kubernetes sheduler and ETCD ? also would like to know what configurations required to get metrics from control plane (scheduler and ETCD,etc..).

I can see that scheduler and ETCD are bound only on the 127.0.0.1 (localhost) at master node.

root@master:/etc/kubernetes# netstat -tnulp | grep 2379
tcp        0      0 127.0.0.1:2379          0.0.0.0:*               LISTEN      1726/etcd       
root@master:/etc/kubernetes# netstat -tnulp | grep 10251
tcp        0      0 127.0.0.1:10251         0.0.0.0:*               LISTEN      7916/kube-scheduler

I am using the default values of HELM chat at https://github.com/helm/charts/tree/master/stable/prometheus-operator to monitor the cluster.