Kubernetes : ノードを削除する2025/05/20 |
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既存の Kubernetes クラスターからノードを削除する場合は以下のように設定します。 |
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| [1] | Control Plane ノードを削除する場合のみ、事前に Etcd の削除やロードバランス設定の削除を実行します。 |
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[root@ctrl ~]# kubectl get nodes NAME STATUS ROLES AGE VERSION dlp-1.srv.world Ready control-plane 117m v1.31.9 dlp.srv.world Ready control-plane 3h3m v1.31.9 node01.srv.world Ready <none> 178m v1.31.9 node02.srv.world Ready <none> 177m v1.31.9 node03.srv.world Ready <none> 38s v1.31.9[root@ctrl ~]# kubectl get pods -n kube-system | grep etcd etcd-dlp-1.srv.world 1/1 Running 0 120m etcd-dlp.srv.world 1/1 Running 2 3h5m # 例として [dlp-1.srv.world] を削除する # 削除しない方の Control Plane で起動している Etcd へアクセスして # 削除対象ノードの設定を削除する [root@ctrl ~]# kubectl -n kube-system exec -it etcd-dlp.srv.world -- sh sh-5.2# sh-5.2# etcdctl --endpoints=https://127.0.0.1:2379 --cacert=/etc/kubernetes/pki/etcd/ca.crt --cert=/etc/kubernetes/pki/etcd/peer.crt --key=/etc/kubernetes/pki/etcd/peer.key member list 41771c7b1d23e5, started, dlp-1.srv.world, https://10.0.0.31:2380, https://10.0.0.31:2379, false dd4b95995dc266b1, started, dlp.srv.world, https://10.0.0.30:2380, https://10.0.0.30:2379, false # 削除したいノードのメンバーを削除 sh-5.2# etcdctl --endpoints=https://127.0.0.1:2379 --cacert=/etc/kubernetes/pki/etcd/ca.crt --cert=/etc/kubernetes/pki/etcd/peer.crt --key=/etc/kubernetes/pki/etcd/peer.key member remove 41771c7b1d23e5 Member 41771c7b1d23e5 removed from cluster 63678238411c70a3 sh-5.2# exit exit
[root@ctrl ~]#
vi /etc/nginx/nginx.conf # 対象ノードの設定を削除 stream { upstream k8s-api { server 10.0.0.30:6443; ###server 10.0.0.31:6443; } server { listen 6443; proxy_pass k8s-api; } }[root@ctrl ~]# systemctl reload nginx
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| [2] | ノードをクラスターから削除します。 以降は Control Plane / Worker 共に同じ手順です。 |
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[root@ctrl ~]# kubectl get nodes NAME STATUS ROLES AGE VERSION dlp-1.srv.world Ready control-plane 124m v1.31.9 dlp.srv.world Ready control-plane 3h9m v1.31.9 node01.srv.world Ready <none> 3h4m v1.31.9 node02.srv.world Ready <none> 3h3m v1.31.9 node03.srv.world Ready <none> 6m49s v1.31.9 # 対象ノードを安全に削除するための事前準備 # --ignore-daemonsets ⇒ DeamonSet の Pod は無視 # --delete-emptydir-data ⇒ emptyDir ボリュームを持つ Pod は無視 # --force ⇒ 単体で作成された Pod も削除 [root@ctrl ~]# kubectl drain dlp-1.srv.world --ignore-daemonsets --delete-emptydir-data --force node/dlp-1.srv.world cordoned Warning: ignoring DaemonSet-managed Pods: kube-system/calico-node-m9cc9, kube-system/kube-proxy-4r2xt node/dlp-1.srv.world drained # 一定時間経過後に確認 # 時間は環境によって異なる [root@ctrl ~]# kubectl get nodes dlp-1.srv.world NAME STATUS ROLES AGE VERSION dlp-1.srv.world Ready,SchedulingDisabled control-plane 125m v1.31.9 # 削除処理を実行 [root@ctrl ~]# kubectl delete node dlp-1.srv.world node "dlp-1.srv.world" deleted[root@ctrl ~]# kubectl get nodes NAME STATUS ROLES AGE VERSION dlp.srv.world Ready control-plane 3h11m v1.31.9 node01.srv.world Ready <none> 3h6m v1.31.9 node02.srv.world Ready <none> 3h5m v1.31.9 node03.srv.world Ready <none> 8m46s v1.31.9 |
| [3] | 削除したノードで、kubeadm の設定をリセットしておきます。 |
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[root@dlp-1 ~]# 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' W0520 12:50:42.776277 36142 reset.go:123] [reset] Unable to fetch the kubeadm-config ConfigMap from cluster: failed to get node registration: failed to get corresponding node: nodes "dlp-1.srv.world" not found W0520 12:50:42.776743 36142 preflight.go:56] [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 W0520 12:50:44.299139 36142 removeetcdmember.go:106] [reset] No kubeadm config, using etcd pod spec to get data directory [reset] Deleted contents of the etcd data directory: /var/lib/etcd [reset] Stopping the kubelet service [reset] Unmounting mounted directories in "/var/lib/kubelet" [reset] Deleting contents of directories: [/etc/kubernetes/manifests /var/lib/kubelet /etc/kubernetes/pki] [reset] Deleting files: [/etc/kubernetes/admin.conf /etc/kubernetes/super-admin.conf /etc/kubernetes/kubelet.conf /etc/kubernetes/bootstrap-kubelet.conf /etc/kubernetes/controller-manager.conf /etc/kubernetes/scheduler.conf] The reset process does not clean CNI configuration. To do so, you must remove /etc/cni/net.d The reset process does not reset or clean up iptables rules or IPVS tables. If you wish to reset iptables, you must do so manually by using the "iptables" command. If your cluster was setup to utilize IPVS, run ipvsadm --clear (or similar) to reset your system's IPVS tables. The reset process does not clean your kubeconfig files and you must remove them manually. Please, check the contents of the $HOME/.kube/config file. |
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