Kubernetes certificate always disappear after few hours
This is an expected behavior for security reasons. You should download the certificate using below command and keep it safe.
kubectl get csr my-svc.my-namespace -o jsonpath='{.status.certificate}' \ | base64 --decode > server.crthttps://kubernetes.io/docs/tasks/tls/managing-tls-in-a-cluster/#download-the-certificate-and-use-it
csr is short for Certificate Signing Requests
It dismiss after validated.
If your want to check certificates:
kubectl get cert -A-A for --all-namespaces