Retrieve Cluster Health Information Using Kubernetes

The kubectl CLI commands can be used to retrieve information about the Kubernetes cluster components.

Nodes

Retrieve node status

kubectl get nodes

Example output:

NAME       STATUS   ROLES                  AGE   VERSION
ncn-m001   Ready    control-plane,master   27h   v1.20.13
ncn-m002   Ready    control-plane,master   8d    v1.20.13
ncn-m003   Ready    control-plane,master   8d    v1.20.13
ncn-w001   Ready    <none>                 8d    v1.20.13
ncn-w002   Ready    <none>                 8d    v1.20.13
ncn-w003   Ready    <none>                 8d    v1.20.13

Pods

Retrieve information about individual pods

kubectl describe pod POD_NAME -n NAMESPACE_NAME

Retrieve a list of all pods

kubectl get pods -A

Retrieve a list of healthy pods

kubectl get pods -A | grep -E 'Completed|Running'

Retrieve a list of unhealthy pods

  • Option 1: List all pods that are not reported as Completed or Running.

    kubectl get pods -A | grep -Ev 'Completed|Running'

  • Option 2: List all pods that are reported as Creating, ImagePull, Error, Init, or Crash.

    kubectl get pods -A | grep -E 'Creating|ImagePull|Error|Init|Crash'

Retrieve status of pods in a specific namespace

kubectl get pods -n NAMESPACE_NAME

Example output for vault namespace:

NAME                                     READY   STATUS      RESTARTS   AGE
cray-vault-0                             5/5     Running     2          7d
cray-vault-1                             5/5     Running     2          7d
cray-vault-2                             5/5     Running     2          7d
cray-vault-configurer-7c7dcdb958-p8jfv   2/2     Running     0          7d
cray-vault-operator-b48b7874f-flstw      2/2     Running     1          7d
spire-intermediate-1-ltzwk               0/2     Completed   0          7d

Retrieve pod logs

kubectl logs -n NAMESPACE_NAME POD_NAME

Services

Retrieve a list of all services

kubectl get services -A

Retrieve status of services in a specific namespace

kubectl get services -n NAMESPACE_NAME

Example output for operators namespace:

NAME                                TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)             AGE
cray-hms-trs-operator-metrics       ClusterIP   10.16.222.4     <none>        8383/TCP,8686/TCP   7d
cray-kiali-kiali-operator-metrics   ClusterIP   10.20.177.208   <none>        8383/TCP,8686/TCP   7d
etcd-restore-operator               ClusterIP   10.28.72.18     <none>        19999/TCP           7d