Prometheus Alert Rule for Absent Discovered Target

user_9320182 0
Viewed 1989

I got an alert while configuring the monitoring module using prometheus/kube-prometheus-stack 25.1.0.

Alert

[FIRING:1] KubeProxyDown - critical
Alert: Target disappeared from Prometheus target discovery. - critical
 Description: KubeProxy has disappeared from Prometheus target discovery.
 Details:
  • alertname: KubeProxyDown
  • prometheus: monitoring/prometheus-kube-prometheus-prometheus
  • severity: critical

I think it is a new default rule in kube-prometheus-stack 25.x.x. It does not exist in prometheus/kube-prometheus-stack 21.x.x.

The same issue happened in the EKS and minikube.

KubeProxyDown Rule

alert: KubeProxyDown
expr: absent(up{job="kube-proxy"}
  == 1)
for: 15m
labels:
  severity: critical
annotations:
  description: KubeProxy has disappeared from Prometheus target discovery.
  runbook_url: https://runbooks.prometheus-operator.dev/runbooks/kubernetes/kubeproxydown
  summary: Target disappeared from Prometheus target discovery.

How can I resolve this issue?

I would be thankful if anyone could help me

prometheus-alertmanager prometheus kubernetes
2 Answers

There was a change in metrics-bind-address in kube-proxy. Following the issues posted here, here and here. I can suggest the following. Change kube-proxy ConfigMap to different value:

$ kubectl edit cm/kube-proxy -n kube-system
## Change from
    metricsBindAddress: 127.0.0.1:10249 ### <--- Too secure
## Change to
    metricsBindAddress: 0.0.0.0:10249
$ kubectl delete pod -l k8s-app=kube-proxy -n kube-system
user_175792520

This is what worked for me in AWS EKS cluster v1.21:

$ kubectl edit cm/kube-proxy-config -n kube-system
---
metricsBindAddress: 127.0.0.1:10249 ### <--- change to 0.0.0.0:10249
$ kubectl delete pod -l k8s-app=kube-proxy -n kube-system

Note, the name of the config map is kube-proxy-config, not kube-proxy

user_26191880
Related