Lab 3.2 - Step 11. cannot create token on worker

telcomx

Hi. Have a problem when creating a token on worker (step 11 Lab 3.2 - Growing the Cluster).

root@ip-172-31-35-153:~# sudo kubeadm token list
failed to load admin kubeconfig: open /root/.kube/config: no such file or directory
To see the stack trace of this error execute with --v=5 or higher
root@ip-172-31-35-153:~#

Any help is much appreciated.

triaris

kubeadm token <list,create,...> commands are run on the cp. You can use these tokens in the kubeadm join command on the worker

telcomx

Hi Triaris, actually that's the error I have from cp node.

ubuntu@ip-172-31-27-178:~$ kubeadm token list
failed to list bootstrap tokens: Get "https://k8scp:6443/api/v1/namespaces/kube-system/secrets?fieldSelector=type=bootstrap.kubernetes.io/token": dial tcp 172.31.27.178:6443: connect: connection refused
To see the stack trace of this error execute with --v=5 or higher
ubuntu@ip-172-31-27-178:~$

chrispokorni

Hi @telcomx,

When bootstrapping the cluster, did you follow the video from the introductory chapter, and are you running the recommended VM guest OS and version?

Regards,
-Chris

telcomx

Hi @chrispokorni
Yes, I am using AWS with two EC2 instances, one as CP (t2.medium) and one WORKER (t2.micro).
Did setup securoty groups as ALL open as per video suggest.
Picture attached.

chrispokorni

Hi @telcomx,

The selected t2 sizes may not be sufficient. What OS distribution and version is installed on the EC2s?

Regards,
-Chris

telcomx

I am using ubuntu-jammy-22.04-amd64-server-20230208 distro.

chrispokorni

Hi @telcomx,

Please use the version recommended in the lab guide.

Regards,
-Chris

telcomx

so shall i reinstall from scratch or there's an option to make downgrade on aws?

telcomx

FYI @chrispokorni

Had to rebuild whole cp and worker as t2.large from scratch using recommended ubuntu and worked. Finally i managed to complete LAB 3.2 Thanks.

ubuntu@ip-172-31-20-93:~$ sudo kubeadm join --token 0692sx.xjxhhcj7gobtwfs5 k8scp:6443 --discovery-token-ca-cert-hash sha256:05a1165104ec15bafbf51690cb5eb3944b2648af728a077671884e1bd38a2af9
[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 -o yaml'
[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.

ubuntu@ip-172-31-20-93:~$ kubectl get nodes
The connection to the server localhost:8080 was refused - did you specify the right host or port?
ubuntu@ip-172-31-20-93:~$
ubuntu@ip-172-31-20-93:~$
ubuntu@ip-172-31-20-93:~$
ubuntu@ip-172-31-20-93:~$ ls -l .kube
ls: cannot access '.kube': No such file or directory
ubuntu@ip-172-31-20-93:~$
ubuntu@ip-172-31-20-93:~$
ubuntu@ip-172-31-20-93:~$