쿠버네티스 노드 추가하기

새로운 노드를 추가하기위해서는 token과 discovery-token-ca-cert-hash가 필요합니다.

token생성

[root@k8s-master ~]# kubeadm token create
    W0418 03:38:30.103931   29081 configset.go:202] WARNING: kubeadm cannot validate component configs for API groups [kubelet.config.k8s.io kubeproxy.config.k8s.io]
    2mt2fr.vamluzvusmol403t

discovery-token-ca-cert-hash 값

 [root@k8s-master ~]# openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt | openssl rsa -pubin -outform der 2>/dev/null | openssl dgst -sha256 -hex | sed 's/^.* //'
    02ad4630328d720e8d9567e1ab0d8bf6d98c243bedd10b827537c189b49fc7c1

token과 discovery-token-ca-cert-hash 값을 복사해서

새로 추가할 노드에 kubeadm join 을 실행해줍니다.

    kubeadm join [master ip:6443] --token [2mt2fr.vamluzvusmol403t] --discovery-token-ca-cert-hash sha256:[02ad4630328d720e8d9567e1ab0d8bf6d98c243bedd10b827537c189b49fc7c1]

ex)

    [root@k8s-node03 ~]# kubeadm join 192.168.1.11:6443 --token 2mt2fr.vamluzvusmol403t --discovery-token-ca-cert-hash sha256:02ad4630328d720e8d9567e1ab0d8bf6d98c243bedd10b827537c189b49fc7c1
    W0418 03:41:56.788876   30738 join.go:346] [preflight] WARNING: JoinControlPane.controlPlane settings will be ignored when control-plane flag is not set.
    [preflight] Running pre-flight checks
    [preflight] Reading configuration from the cluster...
    [preflight] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -oyaml'
    [kubelet-start] Downloading configuration for the kubelet from the "kubelet-config-1.18" ConfigMap in the kube-system namespace
    [kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
    [kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
    [kubelet-start] Starting the kubelet
    [kubelet-start] Waiting for the kubelet to perform the TLS Bootstrap...

    This node has joined the cluster:
    * Certificate signing request was sent to apiserver and a response was received.
    * The Kubelet was informed of the new secure connection details.

    Run 'kubectl get nodes' on the control-plane to see this node join the cluster.

k8s events 확인

    [root@k8s-master ~]# kubectl get events
    LAST SEEN   TYPE     REASON                    OBJECT            MESSAGE
    21m         Normal   Starting                  node/k8s-node03   Starting kubelet.
    21m         Normal   NodeHasSufficientMemory   node/k8s-node03   Node k8s-node03 status is now: NodeHasSufficientMemory
    21m         Normal   NodeHasNoDiskPressure     node/k8s-node03   Node k8s-node03 status is now: NodeHasNoDiskPressure
    21m         Normal   NodeHasSufficientPID      node/k8s-node03   Node k8s-node03 status is now: NodeHasSufficientPID
    21m         Normal   NodeAllocatableEnforced   node/k8s-node03   Updated Node Allocatable limit across pods
    21m         Normal   RegisteredNode            node/k8s-node03   Node k8s-node03 event: Registered Node k8s-node03 in Controller
    20m         Normal   Starting                  node/k8s-node03   Starting kube-proxy.
    20m         Normal   NodeReady                 node/k8s-node03   Node k8s-node03 status is now: NodeReady

노드 상세 확인

    kubectl get node -o wide

ex)

    [root@k8s-master ~]# kubectl get node -o wide
    NAME         STATUS   ROLES    AGE     VERSION   INTERNAL-IP    EXTERNAL-IP   OS-IMAGE                KERNEL-VERSION                CONTAINER-RUNTIME
    k8s-master   Ready    master   5d21h   v1.18.1   192.168.1.11   <none>        CentOS Linux 7 (Core)   3.10.0-1062.18.1.el7.x86_64   docker://19.3.8
    k8s-node01   Ready    <none>   5d21h   v1.18.1   192.168.1.12   <none>        CentOS Linux 7 (Core)   3.10.0-1062.18.1.el7.x86_64   docker://19.3.8
    k8s-node02   Ready    <none>   5d21h   v1.18.1   192.168.1.13   <none>        CentOS Linux 7 (Core)   3.10.0-1062.18.1.el7.x86_64   docker://19.3.8
    k8s-node03   Ready    <none>   5m53s   v1.18.2   192.168.1.14   <none>        CentOS Linux 7 (Core)   3.10.0-1062.18.1.el7.x86_64   docker://19.3.8