kubekey/builtin/core/playbooks/delete_nodes.yaml

---
# Load default variables and perform prechecks on all hosts
- hosts:
    - all
  gather_facts: true
  roles:
    - defaults
    - precheck

- hosts:
    - kube_control_plane
  gather_facts: true
  tasks:
    - name: DeleteNode | Ensure at least one control plane node remains in the cluster
      run_once: true
      command: |
        {{- $cpNodes := list -}}
        {{- range .groups.kube_control_plane -}}
          {{- if index $.hostvars . "kubernetes_install_LoadState" "stdout" | eq "loaded" -}}
            {{- $cpNodes = append $cpNodes . -}}
          {{- end -}}
        {{- end -}}
        {{- if (subtractList $cpNodes .delete_nodes) | empty }}
        echo "At least one control plane node must be retained in the cluster." >&2
        exit 1
        {{- end }}        

- hosts: 
    - k8s_cluster
  pre_tasks:
    - name: DeleteNode | Remove node from Kubernetes cluster
      when: .delete_nodes | default list | has .inventory_hostname
      command: |
        if kubectl get node {{ .hostname }} > /dev/null 2>&1; then
          kubectl cordon {{ .hostname }}
          if [ $(kubectl get nodes --no-headers | wc -l) -gt 1 ]; then
            kubectl drain {{ .hostname }} --ignore-daemonsets --delete-emptydir-data --force --disable-eviction
          else
            kubectl drain {{ .hostname }} --ignore-daemonsets --delete-emptydir-data --force
          fi
        {{- if .cni.type | eq "calico" }}
          calicoctl delete node {{ .hostname }}
        {{- end }}
          kubectl delete node {{ .hostname }}
        fi        
  roles:
    - role: uninstall/kubernetes
      when: .delete_nodes | default list | has .inventory_hostname
    - role: uninstall/cri
      when: 
        - .deleteCRI
        - .groups.image_registry | default list | has .inventory_hostname | not
        - .delete_nodes | default list | has .inventory_hostname
  post_tasks:
    - name: DeleteNode | Clean up local DNS configuration files
      ignore_errors: true
      loop: "{{ .native.localDNS | toJson }}"
      command: |
        sed -i ':a;$!{N;ba};s@# kubekey hosts BEGIN.*# kubekey hosts END@@' {{ .item }}
        sed -i ':a;$!{N;ba};s@# kubekey kubernetes control_plane_endpoint BEGIN.*# kubekey kubernetes control_plane_endpoint END@@' {{ .item }}
        sed -i ':a;$!{N;ba};s@# kubekey image_registry control_plane_endpoint BEGIN.*# kubekey image_registry control_plane_endpoint END@@' {{ .item }}        
      when: 
        - .deleteDNS
        - .delete_nodes | default list | has .inventory_hostname

- hosts:
    - etcd
  roles:
    - role: uninstall/etcd
      when: 
        - .deleteETCD
        - .delete_nodes | default list | has .inventory_hostname

- hosts:
   - image_registry
  roles:
    - role: uninstall/image-registry
      when:
       - .deleteImageRegistry
       - .delete_nodes | default list | has .inventory_hostname