kubekey/builtin/core/playbooks/delete_nodes.yaml

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

- hosts:
    - etcd
  roles:
    - role: etcd
      when: 
        - .delete.etcd
        - .etcd.deployment_type | eq "external"

- hosts:
    - kube_control_plane
  pre_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 }}        
  tasks:
    - name: DeleteNode | Update etcd certificate for kube_control_plane
      when: 
        - .delete.etcd
        - .etcd.deployment_type | eq "external"
      block:
        - name: DeleteNode | Check if should update apiserver certificates
          run_once: true
          add_hostvars:
            hosts: kube_control_plane
            vars:
              need_uninstall_etcd: >-
                {{- $needUnInstalled := list -}}
                {{- range .groups.etcd -}}
                  {{- if $.delete_nodes | default list | has . -}}
                    {{- $needUnInstalled = append $needUnInstalled . -}}
                  {{- end -}}
                {{- end -}}
                {{ $needUnInstalled | toJson }}                  
        - name: DeleteNode | Update apiserver etcd certificates
          when:
            - .need_uninstall_etcd | fromJson | empty | not
          block:
            - name: DeleteNode | Copy etcd CA certificate to control plane node
              copy:
                src: >-
                  {{ .etcd.ca_file }}                  
                dest: /etc/kubernetes/pki/etcd/ca.crt
            - name: DeleteNode | Copy etcd client certificate to control plane node
              copy:
                src: >-
                  {{ .etcd.cert_file }}                  
                dest: /etc/kubernetes/pki/etcd/client.crt
            - name: DeleteNode | Copy etcd client key to control plane node
              copy:
                src: >-
                  {{ .etcd.key_file }}                  
                dest: /etc/kubernetes/pki/etcd/client.key
            - name: DeleteNode | update ks-apiserver
              command: |
                {{- $endpoints := list -}}
                {{- range .groups.etcd | default list -}}
                  {{- if $.need_uninstall_etcd | fromJson | has . | not -}}
                    {{- $endpoints = append $endpoints (printf "https://%s:2379" (index $.hostvars . "internal_ipv4")) -}}
                  {{- end -}}
                {{- end -}}
                ETCD_ENDPOINTS="{{ join "," $endpoints }}"

                if ! grep -q 'ClusterConfiguration' /etc/kubernetes/kubeadm-config.yaml 2>/dev/null; then
                  kubectl get cm kubeadm-config -n kube-system -o=jsonpath='{.data.ClusterConfiguration}' > /etc/kubernetes/kubeadm-config.yaml
                fi

                awk -v ep="$ETCD_ENDPOINTS" '
                  BEGIN {
                    n = split(ep, arr, ",")
                    for (i = 1; i <= n; i++) {
                      print "      - " arr[i]
                    }
                  }
                ' > /etc/kubernetes/kubeadm_new_endpoints.yaml
                # delete old endpoint
                sed -i '/^[[:space:]]*endpoints:/{
                  :loop
                  N
                  s/\n[[:space:]]\+-.*//; t loop
                  s/\n[[:space:]]*\n/\n/g
                  P
                  D
                }' /etc/kubernetes/kubeadm-config.yaml
                # insert new endpoint
                sed -i "/^[[:space:]]*endpoints:/r /etc/kubernetes/kubeadm_new_endpoints.yaml" /etc/kubernetes/kubeadm-config.yaml        
                rm /etc/kubernetes/kubeadm_new_endpoints.yaml
                # update kubeadm-config
                {{- if .kubernetes.kube_version | semverCompare "<v1.27.0" }}
                kubeadm config upload from-file --config /etc/kubernetes/kubeadm-config.yaml
                {{- else }}
                kubeadm init phase upload-config kubeadm --config /etc/kubernetes/kubeadm-config.yaml
                {{- end }}
                # regenerate kube-apiserver
                kubeadm init phase control-plane apiserver --config /etc/kubernetes/kubeadm-config.yaml                

- 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 [ $(kubectl get nodes --no-headers | wc -l) -gt 1 ]; then
            kubectl drain {{ .hostname }} --ignore-daemonsets --delete-emptydir-data --force --disable-eviction
          else
            kubectl drain {{ .hostname }} --ignore-daemonsets --delete-emptydir-data --force
          fi
        {{- if .cni.type | eq "calico" }}
          calicoctl delete node {{ .hostname }}
        {{- end }}
          kubectl delete node {{ .hostname }}
        fi        
  roles:
    - role: uninstall/kubernetes
      when: .delete_nodes | default list | has .inventory_hostname
    - role: uninstall/cri
      when: 
        - .delete.cri
        - .groups.image_registry | default list | has .inventory_hostname | not
        - .delete_nodes | default list | has .inventory_hostname
  post_tasks:
    - name: DeleteNode | Clean up local DNS configuration files
      ignore_errors: true
      loop: "{{ .native.localDNS | toJson }}"
      command: |
        sed -i ':a;$!{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: 
        - .delete.dns
        - .delete_nodes | default list | has .inventory_hostname

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