Kubeadm join fails

Kubernetes
#1

I am practicing the install Kubeadm lab. Everything works fine, on bothe controlplane and node01, but.

When I try he Kubeadm join command,
(kubeadm join 192.30.22.12:6443 --token o2m9xt.1rdkfy7zblydqzsj \

    --discovery-token-ca-cert-hash sha256:7fdc7e68e036bcabd15c26a927139f0baa4aaed26afc55a4fdcdc1cf66f43355)

I get an error

[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 Port-10250]: Port 10250 is in use
[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

What should I do to fix this?

#2

Some investigation shows
netstat -plnt|grep 1025tcp 0 0 127.0.0.1:10257 0.0.0.0:* LISTEN 19712/kube-controll
tcp 0 0 127.0.0.1:10259 0.0.0.0:* LISTEN 19656/kube-schedule
tcp6 0 0 :::10250 :::* LISTEN 22377/kubelet
tcp6 0 0 :::10256 :::* LISTEN 20907/kube-proxy

I kill 22377, but running kubeadm init again gives the same error.

#3

The short answer is that the node is already joined; kubeadm doesn’t want you to try to join it to the cluster more than once…

#4

Hmm. The check answer fails. So I don’t think the node is joined?

#5

The error was trying to join from the control plane. It should have been after ssh to node01. :man_facepalming:

#6

I also got this issue, additionally i had to manually kill kubelet , using

$ pkill kubelet

kubeadm init worked without issues after this,.