Kubernetes : Configure Master Node2021/05/11 |
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Install Kubeadm to Configure Multi Nodes Kubernetes Cluster.
This example is based on the environment like follows.
-----------+---------------------------+--------------------------+------------
| | |
eth0|10.0.0.30 eth0|10.0.0.51 eth0|10.0.0.52
+----------+-----------+ +-----------+----------+ +-----------+----------+
| [ dlp.srv.world ] | | [ node01.srv.world ] | | [ node02.srv.world ] |
| Master Node | | Worker Node | | Worker Node |
+----------------------+ +----------------------+ +----------------------+
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| [1] |
| [2] |
Configure initial setup on Master Node.
For [--apiserver-advertise-address] option, specify the IP address Kubernetes API server listens.
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 selects Calico.
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# need the same version on Kubernetes and CRI-O [root@dlp ~]# kubeadm init --apiserver-advertise-address=10.0.0.30 --pod-network-cidr=192.168.0.0/16 --cri-socket=unix:///var/run/crio/crio.sock --kubernetes-version=1.20.0
[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
.....
.....
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/
Then you can join any number of worker nodes by running the following on each as root:
# the command below is necessary to run on Worker Node when he joins to the cluster, so remember it
kubeadm join 10.0.0.30:6443 --token xme2jq.gb2sgglicnpqqshv \
--discovery-token-ca-cert-hash sha256:2f597590adfff75d6c1394cef5b5209b2e58f52c8c54b8a3630367ac3991fb59
# set cluster admin user # if you set common user as cluster admin, login with it and run [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
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| [3] | Configure Pod Network with Calico. |
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[root@dlp ~]# wget https://docs.projectcalico.org/manifests/calico.yaml [root@dlp ~]# kubectl apply -f calico.yaml configmap/calico-config created customresourcedefinition.apiextensions.k8s.io/bgpconfigurations.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/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/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 clusterrolebinding.rbac.authorization.k8s.io/calico-kube-controllers created clusterrole.rbac.authorization.k8s.io/calico-node created clusterrolebinding.rbac.authorization.k8s.io/calico-node created daemonset.apps/calico-node created serviceaccount/calico-node created deployment.apps/calico-kube-controllers created serviceaccount/calico-kube-controllers created poddisruptionbudget.policy/calico-kube-controllers created # show state : OK if STATUS = Ready [root@dlp ~]# kubectl get nodes NAME STATUS ROLES AGE VERSION dlp.srv.world Ready control-plane,master 3m27s v1.20.5 # show state : OK if all are Running [root@dlp ~]# kubectl get pods -A NAMESPACE NAME READY STATUS RESTARTS AGE kube-system calico-kube-controllers-6d7b4db76c-6rp8z 1/1 Running 0 108s kube-system calico-node-494s2 1/1 Running 0 108s kube-system coredns-74ff55c5b-2kdm9 1/1 Running 0 3m19s kube-system coredns-74ff55c5b-dftgb 1/1 Running 0 3m19s kube-system etcd-dlp.srv.world 1/1 Running 0 3m31s kube-system kube-apiserver-dlp.srv.world 1/1 Running 0 3m31s kube-system kube-controller-manager-dlp.srv.world 1/1 Running 0 3m31s kube-system kube-proxy-pxwmg 1/1 Running 0 3m19s kube-system kube-scheduler-dlp.srv.world 1/1 Running 0 3m31s |
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