Kubernetes not able to find metric-server api.I am using Kubernetes with Docker on Mac. I was trying to do HPA from following example. However, when I execute command kubectl get hpa, My target still was unknown. Then I tried, kubectl describe hpa. Which gave me error like below:
Name: php-apache
Namespace: default
Labels: <none>
Annotations: <none>
CreationTimestamp: Sun, 07 Oct 2018 12:36:31 -0700
Reference: Deployment/php-apache
Metrics: ( current / target )
resource cpu on pods (as a percentage of request): <unknown> / 5%
Min replicas: 1
Max replicas: 10
Conditions:
Type Status Reason Message
---- ------ ------ -------
AbleToScale True SucceededGetScale the HPA controller was able to get the target's current scale
ScalingActive False FailedGetResourceMetric the HPA was unable to compute the replica count: unable to get metrics for resource cpu: no metrics returned from resource metrics API
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Warning FailedComputeMetricsReplicas 1h (x34 over 5h) horizontal-pod-autoscaler failed to get cpu utilization: unable to get metrics for resource cpu: no metrics returned from resource metrics API
Warning FailedGetResourceMetric 1m (x42 over 5h) horizontal-pod-autoscaler unable to get metrics for resource cpu: no metrics returned from resource metrics API
I am using metrics-server as suggested in Kubernetes documentation. I also tried doing same just using Minikube. But that also didn't work.
Running kubectl get --raw /apis/metrics.k8s.io/v1beta1/nodes outputs :
{
"kind": "NodeMetricsList",
"apiVersion": "metrics.k8s.io/v1beta1",
"metadata": {
"selfLink": "/apis/metrics.k8s.io/v1beta1/nodes"
},
"items": []
}
Use official metrics server - https://github.com/kubernetes-sigs/metrics-server
If you use one master node, run this command to create the metrics-server:
kubectl apply -f https://github.com/kubernetes-sigs/metrics-server/releases/latest/download/components.yaml
If you have HA (High availability) cluster, use this:
kubectl apply -f https://github.com/kubernetes-sigs/metrics-server/releases/latest/download/high-availability.yaml
Then use can use kubectl top nodes or kubectl top pods -A and get something like:
NAME CPU(cores) CPU% MEMORY(bytes) MEMORY%