Kubernetes : Control Plane ノードの設定2024/05/13

Kubeadm をインストールして、マルチノード Kubernetes クラスターを構成します。

当例では以下のように 3 台のノードを使用して設定します。

-----------+---------------------------+--------------------------+------------
           |                           |                          |
       eth0|10.0.0.30              eth0|10.0.0.51             eth0|10.0.0.52
+----------+-----------+   +-----------+----------+   +-----------+----------+
|   [ dlp.srv.world ]  |   | [ node01.srv.world ] |   | [ node02.srv.world ] |
|     Control Plane    |   |      Worker Node     |   |      Worker Node     |
+----------------------+   +----------------------+   +----------------------+

[1]	事前に全ノードに Kubeadm インストール等々、ノード共通の設定を適用しておきます。

[2]

Control Plane ノードで初期セットアップします。

[control-plane-endpoint] には Etcd や Kubernetes API サーバー等のコンポーネントが実行されるホストの IP アドレスを指定します。

[--pod-network-cidr] には、Pod Network が利用するネットワークを指定します。
Pod Network を構成するためのプラグインはいくつかのソフトウェアから選択可能です。(詳細は下記リンク参照)

⇒ https://kubernetes.io/docs/concepts/cluster-administration/networking/

当例では Calico で進めます。

[root@dlp ~]#

kubeadm init --control-plane-endpoint=10.0.0.30 --pod-network-cidr=192.168.0.0/16 --cri-socket=unix:///var/run/crio/crio.sock

[init] Using Kubernetes version: v1.29.4
[preflight] Running pre-flight checks
[preflight] Pulling images required for setting up a Kubernetes cluster
[preflight] This might take a minute or two, depending on the speed of your internet connection
[preflight] You can also perform this action in beforehand using 'kubeadm config images pull'
[certs] Using certificateDir folder "/etc/kubernetes/pki"
[certs] Generating "ca" certificate and key
[certs] Generating "apiserver" certificate and key
[certs] apiserver serving cert is signed for DNS names [dlp.srv.world kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 10.0.0.30]
[certs] Generating "apiserver-kubelet-client" certificate and key

.....
.....

Your Kubernetes control-plane has initialized successfully!

To start using your cluster, you need to run the following as a regular user:

  mkdir -p $HOME/.kube
  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
  sudo chown $(id -u):$(id -g) $HOME/.kube/config

Alternatively, if you are the root user, you can run:

  export KUBECONFIG=/etc/kubernetes/admin.conf

You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
  https://kubernetes.io/docs/concepts/cluster-administration/addons/

You can now join any number of control-plane nodes by copying certificate authorities
and service account keys on each node and then running the following as root:

  kubeadm join 10.0.0.30:6443 --token katr7o.jdyxjkbljrtbubel \
        --discovery-token-ca-cert-hash sha256:a0dc94201791381a68ee3b051844843b79b1002f718dfdea4a1b833cee72ff7b \
        --control-plane

Then you can join any number of worker nodes by running the following on each as root:

kubeadm join 10.0.0.30:6443 --token katr7o.jdyxjkbljrtbubel \
        --discovery-token-ca-cert-hash sha256:a0dc94201791381a68ee3b051844843b79b1002f718dfdea4a1b833cee72ff7b

# クラスター管理ユーザーの設定
# 一般ユーザーを管理ユーザーとする場合は、該当ユーザー自身で sudo cp/chown ***

[root@dlp ~]#

mkdir -p $HOME/.kube

[root@dlp ~]#

cp -i /etc/kubernetes/admin.conf $HOME/.kube/config

[root@dlp ~]#

chown $(id -u):$(id -g) $HOME/.kube/config

[3]	Calico での Pod Network を構成します。

[root@dlp ~]#

wget https://raw.githubusercontent.com/projectcalico/calico/master/manifests/calico.yaml

[root@dlp ~]#

kubectl apply -f calico.yaml

poddisruptionbudget.policy/calico-kube-controllers created
serviceaccount/calico-kube-controllers created
serviceaccount/calico-node created
serviceaccount/calico-cni-plugin created
configmap/calico-config created
customresourcedefinition.apiextensions.k8s.io/bgpconfigurations.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/bgpfilters.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/bgppeers.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/blockaffinities.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/caliconodestatuses.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/clusterinformations.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/felixconfigurations.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/globalnetworkpolicies.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/globalnetworksets.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/hostendpoints.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/ipamblocks.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/ipamconfigs.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/ipamhandles.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/ippools.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/ipreservations.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/kubecontrollersconfigurations.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/networkpolicies.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/networksets.crd.projectcalico.org created
clusterrole.rbac.authorization.k8s.io/calico-kube-controllers created
clusterrole.rbac.authorization.k8s.io/calico-node created
clusterrole.rbac.authorization.k8s.io/calico-cni-plugin created
clusterrolebinding.rbac.authorization.k8s.io/calico-kube-controllers created
clusterrolebinding.rbac.authorization.k8s.io/calico-node created
clusterrolebinding.rbac.authorization.k8s.io/calico-cni-plugin created
daemonset.apps/calico-node created
deployment.apps/calico-kube-controllers created

# 確認 : STATUS = Ready であれば OK

[root@dlp ~]#

kubectl get nodes

NAME            STATUS   ROLES           AGE     VERSION
dlp.srv.world   Ready    control-plane   2m58s   v1.29.4

# 確認 : 全て Running であれば OK

[root@dlp ~]#

kubectl get pods -A

NAMESPACE     NAME                                       READY   STATUS    RESTARTS   AGE
kube-system   calico-kube-controllers-57758d645c-vpbq9   1/1     Running   0          78s
kube-system   calico-node-w8qh2                          1/1     Running   0          78s
kube-system   coredns-76f75df574-kcqsv                   1/1     Running   0          3m4s
kube-system   coredns-76f75df574-wfgqz                   1/1     Running   0          3m4s
kube-system   etcd-dlp.srv.world                         1/1     Running   0          3m11s
kube-system   kube-apiserver-dlp.srv.world               1/1     Running   0          3m21s
kube-system   kube-controller-manager-dlp.srv.world      1/1     Running   0          3m14s
kube-system   kube-proxy-h222g                           1/1     Running   0          3m4s
kube-system   kube-scheduler-dlp.srv.world               1/1     Running   0          3m20s