Kubernetes : Configure Control Plane Node2023/07/28 |
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Install Kubeadm to Configure Multi Nodes Kubernetes Cluster. This example is based on the environment like follows.
-----------+---------------------------+--------------------------+------------
| | |
eth0|10.0.0.25 eth0|10.0.0.71 eth0|10.0.0.72
+----------+-----------+ +-----------+-----------+ +-----------+-----------+
| [ ctrl.srv.world ] | | [snode01.srv.world] | | [snode02.srv.world] |
| Control Plane | | Worker Node | | Worker Node |
+----------------------+ +-----------------------+ +-----------------------+
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| [1] |
| [2] |
Configure initial setup on Control Plane Node.
For [control-plane-endpoint], specify the Hostname or IP address that Etcd and Kubernetes API server are run.
For [--pod-network-cidr] option, specify network which Pod Network uses.
There are some plugins for Pod Network. (refer to details below)
⇒ https://kubernetes.io/docs/concepts/cluster-administration/networking/
On this example, it uses Calico.
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root@ctrl:~# kubeadm init --control-plane-endpoint=10.0.0.25 --pod-network-cidr=192.168.0.0/16 --cri-socket=unix:///run/containerd/containerd.sock
[init] Using Kubernetes version: v1.30.3
[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 [ctrl.srv.world kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 10.0.0.25]
.....
.....
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 10.0.0.25:6443 --token wmgxmn.abjab1upv8da9bp5 \
--discovery-token-ca-cert-hash sha256:6b0bceac20f9f9e4dea0c52d8ba3b50d565d7e59ddbdeee6fd7544d140ac78fe \
--control-plane
Then you can join any number of worker nodes by running the following on each as root:
kubeadm join 10.0.0.25:6443 --token wmgxmn.abjab1upv8da9bp5 \
--discovery-token-ca-cert-hash sha256:6b0bceac20f9f9e4dea0c52d8ba3b50d565d7e59ddbdeee6fd7544d140ac78fe
# set cluster admin user # if you set common user as cluster admin, login with it and run [sudo cp/chown ***] root@ctrl:~# mkdir -p $HOME/.kube root@ctrl:~# cp -i /etc/kubernetes/admin.conf $HOME/.kube/config root@ctrl:~# chown $(id -u):$(id -g) $HOME/.kube/config
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| [3] | Configure Pod Network with Calico. |
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root@ctrl:~# wget https://raw.githubusercontent.com/projectcalico/calico/master/manifests/calico.yaml root@ctrl:~# 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 # show state : OK if STATUS = Ready root@ctrl:~# kubectl get nodes NAME STATUS ROLES AGE VERSION ctrl.srv.world Ready control-plane 2m9s v1.30.3 # show state : OK if all pods are Running root@ctrl:~# kubectl get pods -A NAMESPACE NAME READY STATUS RESTARTS AGE kube-system calico-kube-controllers-86996b59f4-8zjlx 1/1 Running 0 35s kube-system calico-node-9kklj 1/1 Running 0 35s kube-system coredns-7db6d8ff4d-jmdnv 1/1 Running 0 2m7s kube-system coredns-7db6d8ff4d-klrl7 1/1 Running 0 2m7s kube-system etcd-ctrl.srv.world 1/1 Running 0 2m21s kube-system kube-apiserver-ctrl.srv.world 1/1 Running 0 2m21s kube-system kube-controller-manager-ctrl.srv.world 1/1 Running 0 2m21s kube-system kube-proxy-gpkt2 1/1 Running 0 2m7s kube-system kube-scheduler-ctrl.srv.world 1/1 Running 0 2m21s |
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