Background:
Because it is a local test, the locally built nfs service is used to mount the volume, the host address is configured with dhcp, and the server ip address is automatically changed the next day, causing the k8s test cluster to fail. It is necessary to reset the single master k8s, and kubeadm reset reports an error
[root@master k8s]# kubeadm reset
[reset] Reading configuration from the cluster...
[reset] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -o yaml'
W0619 10:47:23.556038 13352 reset.go:101] [reset] Unable to fetch the kubeadm-config ConfigMap from cluster: failed to get config map: Get "https://172.17.203.139:6443/api/v1/namespaces/kube-system/configmaps/kubeadm-config?timeout=10s": dial tcp 172.17.203.139:6443: connect: no route to host
[reset] WARNING: Changes made to this host by 'kubeadm init' or 'kubeadm join' will be reverted.
[reset] Are you sure you want to proceed? [y/N]: y
[preflight] Running pre-flight checks
W0619 10:53:26.356654 13352 removeetcdmember.go:80] [reset] No kubeadm config, using etcd pod spec to get data directory
[reset] Stopping the kubelet service
[reset] Unmounting mounted directories in "/var/lib/kubelet"
W0619 10:53:26.422655 13352 unmount_linux.go:49] [reset] Failed to unmount mounted directory in /var/lib/kubelet/: /var/lib/kubelet/pods/f84e3e30-8b10-4c84-9f3b-af3690ad291b/volumes/kubernetes.io~nfs/nfs-client-root
W0619 10:53:26.453275 13352 unmount_linux.go:49] [reset] Failed to unmount mounted directory in /var/lib/kubelet/: /var/lib/kubelet/pods/8e87f4de-7ccc-48cb-9cd2-25776fdc1c2a/volumes/kubernetes.io~nfs/pvc-212c8ad0-c482-44e8-90fe-2239d4e22d7e
The reason is that the mounted volume of the started sonarqube service is still mounted and used, but the k8s is not available. The kubectl command delete is invalid, and further judgment is required
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