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While joining worked node to control node all on GCP facing error while running join command

shrikiec
shrikiec Posts: 6
in LFS258 Class Forum

In exercise 3.2 ,the 7th instruction kubeadm join ....
Though gave correctly token and hash

I0502 00:06:17.376217   20381 checks.go:132] validating if the "kubelet" service is enabled and active
I0502 00:06:17.389317   20381 checks.go:205] validating availability of port 10250
I0502 00:06:17.389610   20381 checks.go:282] validating the existence of file /etc/kubernetes/pki/ca.crt
        [WARNING FileAvailable--etc-kubernetes-pki-ca.crt]: /etc/kubernetes/pki/ca.crt already exists
I0502 00:06:17.389688   20381 checks.go:432] validating if the connectivity type is via proxy or direct
[preflight] Some fatal errors occurred:
        [ERROR FileAvailable--etc-kubernetes-kubelet.conf]: /etc/kubernetes/kubelet.conf already exists
[preflight] If you know what you are doing, you can make a check non-fatal with `--ignore-preflight-errors=...`
error execution phase preflight
k8s.io/kubernetes/cmd/kubeadm/app/cmd/phases/workflow.(*Runner).Run.func1
        /workspace/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/cmd/kubeadm/app/cmd/phases/workflow/runner.go:235

Best Answer

  • chrispokorni
    chrispokorni Posts: 2,626
    Answer ✓

    Hi @shrikiec,

    The errors above are typically seen on systems where the kubeadm join command was run several times in a row.

    Please run kubeadm reset on the worker node as root, then attempt once the kubeadm join command on the worker node as root (or with sudo), and capture if/any errors are produced then, to be able to troubleshoot any possible issues. Keep in mind, however, that only "errors" should be of concern, "warnings" are safe to disregard.

    Regards,
    -Chris

Answers

  • shrikiec
    shrikiec Posts: 6

    oot@cp-worked:~# kubeadm join --token xxxx k8scp:6443 --discovery-token-ca-cert-hash sha256:xxxx
    [preflight] Running pre-flight checks
    error execution phase preflight: [preflight] Some fatal errors occurred:
    [ERROR FileAvailable--etc-kubernetes-kubelet.conf]: /etc/kubernetes/kubelet.conf already exists
    [ERROR FileAvailable--etc-kubernetes-pki-ca.crt]: /etc/kubernetes/pki/ca.crt already exists
    [preflight] If you know what you are doing, you can make a check non-fatal with --ignore-preflight-errors=...
    To see the stack trace of this error execute with --v=5 or higher
    root@cp-worked:~#

  • shrikiec
    shrikiec Posts: 6

    Thanks had to add flag for "--cgroup-driver=cgroupfs"

    From stack driver : To solve it, first find Docker cgroup:

    docker info | grep Cgroup

    The result of the above command would be something like this:

    Cgroup Driver: cgroupfs
    Cgroup Version: 1
    Then, update kubelet args (KUBELET_KUBECONFIG_ARGS) in /etc/systemd/system/kubelet.service.d/10-kubeadm.conf and add a --cgroup-driver flag corresponsing to docker cgroup (in this case cgroupfs).

    My config file looks like this after the modification:
    Environment="KUBELET_KUBECONFIG_ARGS=--bootstrap-kubeconfig=/etc/kubernetes/bootstrap-kubelet.conf --kubeconfig=/e`tc/kubernetes/kubelet.conf --cgroup-driver=cgroupfs"

    Finally, run kubeadm reset and then kubeadm init.

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