Kubernetes CKA sample exam question 27 with answer

Question
A pod nginx-pod (image=nginx) in default namespace is not running.
Find the problem and fix it and make it running.

Answer
Get details:

kubectl get po

we can see that the pod nginx-pod is in the Pending state
Get some events:

kubectl describe po nginx-pod

We can notice from events that nodes have taits that pod didn't tolerate:
{color: blue} on 1 node - probably this is node01
{node-role.kubernetes.io/master} on another node - this should be a controlplane
Make sure of above:

kubectl describe node controlplane | grep -i taint
kubectl describe node node01 | grep -i taint

To schedule pod on node01 we should add a toleration color=blue:NoSchedule to the pod.
Get the pod manifest:

kubectl get po nginx-pod -o yaml > po.yaml

Add the following toleration to it:

...
spec:
  tolerations:
  - key: "color"
    operator: "Equal"
    value: "blue"
    effect: "NoSchedule"
..

Save and replace the pod:

kubectl replace --force -f po.yaml

Verify:

kubectl get po -o wide
kubectl describe po nginx-pod

Pod should be scheduled on node01 and to be in Running state