Why does pod status remain 'PENDING'? - linux

Question

Here is the output I am getting:
[root#ip-10-0-3-103 ec2-user]# kubectl get pod --namespace=migration
NAME READY STATUS RESTARTS AGE
clear-nginx-deployment-cc77649fb-j8mzj 0/1 Pending 0 118m
clear-nginx-deployment-temp-cc77649fb-hxst2 0/1 Pending 0 41s
Could not understand the message shown in json:
*"status":
{
"conditions": [
{
"message": "0/1 nodes are available: 1 pod has unbound immediate PersistentVolumeClaims.",
"reason": "Unschedulable",
"status": "False",
"type": "PodScheduled"
}
],
"phase": "Pending",
"qosClass": "BestEffort"
}*
If you could please help to get through this.
The earlier question on stackoverflow doesn't answer my query as my message output is different.

Answer 1

This is due to the fact that your Pods have been instructed to claim storage, however, in your case there is storage available.
Check your Pods with kubectl get pods <pod-name> -o yaml and look at the exact yaml that has been applied to the cluster. In there you should be able to see that the Pod is trying to claim a PersistentVolume (PV).
To quickly create a PV backed by a hostPath apply the following yaml:
apiVersion: v1
kind: PersistentVolume
metadata:
name: stackoverflow-hostpath
namespace: migration
spec:
capacity:
storage: 10Gi
accessModes:
- ReadWriteOnce
hostPath:
path: "/mnt/data"
Kubernetes will exponentially try to schedule the Pod again; to speed things up delete one of your pods (kubectl delete pods <pod-name>) to reschedule it immediately.