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Still unable to connect worker node to cp node

When I execute the "sudo kubeadm join" command on the worker node, I get the following:

[preflight] Running pre-flight checks
error execution phase preflight: couldn't validate the identity of the API Server: Get "https:///api/v1/namespaces/kube-public/configmaps/cluster-info?timeout=10s": net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)
To see the stack trace of this error execute with --v=5 or higher


  • taepyongyang
    taepyongyang Posts: 7
    edited November 2022

    I've performed over a dozen times (with 11.08/11.23) as I'm using a temporary Cloud (GCP) lab on Ubuntu 20.04 LTS.

    Did this occur while using the kubeadm join verbatim?

    grep -A2 join cp.out

    sudo kubeadm join <VPC ASSIGNED_IP_OF_CP>:6443 --token <PRINTED_TOKEN> \
        --discovery-token-ca-cert-hash sha256:<MORE_PRINTED_TOKEN>
  • Hi @tstaffordsmith,

    What type of infrastructure are you on? It seems there is a timeout, that could be caused by a misconfigured firewall. Are you on cloud or local VMs? What OS version, CPU, RAM?


  • Already figured this out but thank you

  • @chrispokorni Hello! I'm experiencing this same issue.

    I'm running on AWS. Using the ubuntu-jammy-22.04-amd64-server-20230919 image. 2cpu. 8gb RAM. 20gb storage. I tried to stay as close to the recommendations from the instructor. I believe I have all types of traffic and all ports allowed on both CP and Worker EC2 instances.

    What would be the next thing I should look at? Thanks for any help!

  • chrispokorni
    chrispokorni Posts: 2,012

    Hi @stmcallister1,

    While the EC2 instance size seems to be adequate, I would recommend using the lab guide recommended OS, that is Ubuntu 20.04 LTS.
    Are both EC2 instances in the same SG? If not, is traffic allowed between the EC2 instance SGs?


  • Huh. That was it! Using Ubuntu 20.04 LTS instead of 22.04 made all the difference.

    Thank you, @chrispokorni!


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