How To Verify the Metrics Server is Installed in the Cluster

Background

The Metrics Server is an aggregator of resource usage data in your Kubernetes cluster. The RealTheory Collector requires the Metrics Server to be installed on the Kubernetes cluster.

Solution

The Metrics Server is automatically installed with some managed versions of Kubernetes. The following table indicates which managed Kubernetes offerings include the Metrics Server as part of the standard offering.

Procedure

There are multiple ways to check if your cluster is running the Metrics Server:

1. Run the following command:

   kubectl get deployment metrics-server \-n kube-system
   

   If the Metrics Server is installed, the output will be similar to the following example:

   NAME             READY   UP-TO-DATE   AVAILABLE   AGE  
   metrics-server   1/1     1            1           25h 
   

2. Alternatively, run the following command:

    kubectl get \--raw "/apis/metrics.k8s.io/v1beta1/nodes" 
   

   If the Metrics Server is installed, the output will be similar to the following example:

   {"kind":"NodeMetricsList","apiVersion":"metrics.k8s.io/v1beta1","metadata":{"selfLink":"/apis/metrics.k8s.io/v1beta1/nodes"},"items":\[{"metadata":  
   {"name":"cirrus12","selfLink":"/apis/metrics.k8s.io/v1beta1/nodes/cirrus12",  
   "creationTimestamp":"2019-08-08T23:59:49Z"},"timestamp":"2019-08-08T23:59:08Z",  
   "window":"30s","usage":{"cpu":"1738876098n","memory":"8406880Ki"}}\]}
   

See Also
For more information on the Kubernetes Metrics Server, including installation instructions, see https://github.com/kubernetes-sigs/metrics-server.