error while set up Prometheus metrics for kubernetes Horizontal Pod Auto-scaling

Question

I'am trying to set up the metrics to activate HPA (Horizontal Pod Auto-scaling) I follow this tutorial only the Custom Metrics (Prometheus) .

Unfortunately when i execute the command below :

  kubectl get --raw /apis/custom.metrics.k8s.io/v1beta1
{"kind":"APIResourceList","apiVersion":"v1","groupVersion":"custom.metrics.k8s.io/v1beta1","resources":[]}  

I must to see a lot of thing on resources however there is nothing.

Answer 1

This might be the issue how you setup metrics-server and metrics-server could not able to find your resources on InternalIP.

The solution is to replace the metrics-server-deployment.yaml file in metrics-server/deploy/1.8+ with the following yaml file:

apiVersion: v1
 kind: ServiceAccount
 metadata:
   name: metrics-server
   namespace: kube-system
 ---
 apiVersion: extensions/v1beta1
 kind: Deployment
 metadata:
   name: metrics-server
   namespace: kube-system
   labels:
     k8s-app: metrics-server
 spec:
   selector:
     matchLabels:
       k8s-app: metrics-server
   template:
     metadata:
       name: metrics-server
       labels:
         k8s-app: metrics-server
     spec:
       serviceAccountName: metrics-server
       volumes:
       # mount in tmp so we can safely use from-scratch images and/or read-only containers
       - name: tmp-dir
         emptyDir: {}
       containers:
       - command:
         - /metrics-server
         - --metric-resolution=30s
         - --kubelet-insecure-tls
         - --kubelet-preferred-address-types=InternalIP
         name: metrics-server
         image: k8s.gcr.io/metrics-server-amd64:v0.3.1
         imagePullPolicy: Always
         volumeMounts:
         - name: tmp-dir
           mountPath: /tmp

Also, enable the --authentication-token-webhook in kubelet.conf, then you will be able to get the metrics.

Also, checkout my answer for step by step instruction to set the HPA using metrics-server.

How to Enable KubeAPI server for HPA Autoscaling Metrics

Hope this helps. Revert back if you face any issues.