Installing metrics-server

If metrics-server is not installed, you will see an error when you try to run kubectl top.

# kubectl top pods
Error from server (NotFound): the server could not find the requested resource (get services http:heapster:)

Alternatively, run kubectl get pods,svc,deployments -n kube-system | grep metrics-server to see if metrics-server is present.

Prerequisites

Install the kubectl binary on your Ansible box
Install the UCP Client bundle for the admin user
Confirm that you can connect to the cluster by running a test command, for example, kubectl get nodes

Download and install `metrics-server`

Download the project from GitHub:

# git clone https://github.com/kubernetes-incubator/metrics-server
# cd metrics-server

Apply all the appropriate yaml files to deploy metrics-server:

# kubectl apply -f deploy/1.8+/

clusterrole.rbac.authorization.k8s.io/system:aggregated-metrics-reader created
clusterrolebinding.rbac.authorization.k8s.io/metrics-server:system:auth-delegator created
rolebinding.rbac.authorization.k8s.io/metrics-server-auth-reader created
apiservice.apiregistration.k8s.io/v1beta1.metrics.k8s.io created
serviceaccount/metrics-server created
deployment.extensions/metrics-server created
service/metrics-server created
clusterrole.rbac.authorization.k8s.io/system:metrics-server created
clusterrolebinding.rbac.authorization.k8s.io/system:metrics-server created

Now, when you run kubectl get pods,svc,deployments -n kube-system, you should see the deployment, pod and service:

NAME                                           READY     STATUS    RESTARTS   AGE
pod/metrics-server-559d9f45f-tg7l6             1/1       Running   0          34s

NAME                     TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)         AGE
service/metrics-server   ClusterIP   10.96.181.69    <none>        443/TCP         34s

NAME                                            DESIRED   CURRENT   UP-TO-DATE   AVAILABLE 
deployment.extensions/metrics-server            1         1         1            1

You can look at the pod logs to ensure that it installed correctly:

# kubectl logs pod/metrics-server-559d9f45f-tg7l6 -n kube-system

I0227 13:50:34.034542       1 serving.go:273] Generated self-signed cert (apiserver.local.config/certificates/apiserver.crt, apiserver.local.config/certificates/apiserver.key)
[restful] 2019/02/27 13:50:34 log.go:33: [restful/swagger] listing is available at https://:443/swaggerapi
[restful] 2019/02/27 13:50:34 log.go:33: [restful/swagger] https://:443/swaggerui/ is mapped to folder /swagger-ui/
I0227 13:50:34.556081       1 serve.go:96] Serving securely on [::]:443

Use metrics-server via `kubectl top`

Now, when you run kubectl top, you should see metrics reported:

[root@hpe-ansible metrics-server]# kubectl top nodes
NAME                              CPU(cores)   CPU%      MEMORY(bytes)   MEMORY%
hpe2-dtr01.am2.cloudra.local      134m         6%        2201Mi          14%
hpe2-dtr02.am2.cloudra.local      106m         5%        2115Mi          13%
hpe2-dtr03.am2.cloudra.local      106m         5%        2154Mi          13%
hpe2-ucp01.am2.cloudra.local      586m         15%       4620Mi          33%
hpe2-ucp02.am2.cloudra.local      525m         14%       4884Mi          35%
hpe2-ucp03.am2.cloudra.local      743m         19%       7321Mi          53%
hpe2-worker01.am2.cloudra.local   360m         9%        4857Mi          7%
hpe2-worker02.am2.cloudra.local   143m         3%        2295Mi          3%
hpe2-worker03.am2.cloudra.local   105m         2%        1362Mi          2%

# Installing metrics-server

# Prerequisites

# Download and install metrics-server

# Use metrics-server via kubectl top

Installing metrics-server

Prerequisites

Download and install `metrics-server`

Use metrics-server via `kubectl top`