I'm pretty new to kubernetes, not so much with docker.
I've been working through the example but I am stuck with the autoscaler, (which doesn't seem to scale).
I am working through the example here https://kubernetes.io/docs/tasks/run-application/horizontal-pod-autoscale-walkthrough/#step-one-run--expose-php-apache-server
You'll find the build at the bottom
kubectl create -f https://k8s.io/docs/tasks/run-application/hpa-php-apache.yaml
Which looks like this
apiVersion: autoscaling/v1
kind: HorizontalPodAutoscaler
metadata:
name: php-apache
namespace: default
spec:
scaleTargetRef:
apiVersion: apps/v1
kind: Deployment
name: php-apache
minReplicas: 1
maxReplicas: 10
targetCPUUtilizationPercentage: 50kubectl get hba shows
NAME REFERENCE TARGETS MINPODS MAXPODS REPLICAS AGE
php-apache Deployment/php-apache <unknown>/50% 1 10 0 7sClue in the <unknown> section.
Then kubectl describe hba shows
Name: php-apache
Namespace: default
Labels: <none>
Annotations: <none>
CreationTimestamp: Sat, 14 Apr 2018 23:05:05 +0100
Reference: Deployment/php-apache
Metrics: ( current / target )
resource cpu on pods (as a percentage of request): <unknown> / 50%
Min replicas: 1
Max replicas: 10
Conditions:
Type Status Reason Message
---- ------ ------ -------
AbleToScale False FailedGetScale the HPA controller was unable to get the target's current scale: deployments/scale.extensions "php-apache" not found
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Warning FailedGetScale 12s (x14 over 6m) horizontal-pod-autoscaler deployments/scale.extensions "php-apache" not found
So then I manually add it in with...
kubectl run php-apache --image=k8s.gcr.io/hpa-example --requests=cpu=200m --expose --port=80
Then if i run kubectl describe hpa again I get this error..
Name: php-apache
Namespace: default
Labels: <none>
Annotations: <none>
CreationTimestamp: Sat, 14 Apr 2018 23:05:05 +0100
Reference: Deployment/php-apache
Metrics: ( current / target )
resource cpu on pods (as a percentage of request): <unknown> / 50%
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: unable to fetch metrics from API: the server could not find the requested resource (get pods.metrics.k8s.io)
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Warning FailedGetScale 1m (x21 over 11m) horizontal-pod-autoscaler deployments/scale.extensions "php-apache" not found
Warning FailedGetResourceMetric 8s (x2 over 38s) horizontal-pod-autoscaler unable to get metrics for resource cpu: unable to fetch metrics from API: the server could not find the requested resource (get pods.metrics.k8s.io)
Warning FailedComputeMetricsReplicas 8s (x2 over 38s) horizontal-pod-autoscaler failed to get cpu utilization: unable to get metrics for resource cpu: unable to fetch metrics from API: the server could not find the requested resource (get pods.metrics.k8s.io)
To answer the question directly, if you have set up an HPA resource and using the metrics server, and ran into this error.
This error means that in your pods, which may have more than one container, either one or both of the containers have not defined resource requests:
Resources:
requests:
cpu: <this is missing! Add it>Check that all containers have resource requests defined.
To add edit and add resources directly, use kubectl edit <resource>
Kubernetes may not allow you to update if your using helm even with the force flag.
A note, this may cause downtime if you have not set PodDisruptionBudgets so set those before you ran your edit
As Heapster is deprecated in later version(v 1.13) of kubernetes, You can expose your metrics using metrics-server also, Please check following answer for step by step instruction to setup HPA: