x509 certificate signed by unknown authority- Kubernetes

Question

I am configuring Kubernetes cluster with 2 nodes in coreos as described in https://coreos.com/kubernetes/docs/latest/getting-started.html without flannel. Both

Answer 1

mkdir -p $HOME/.kube   
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config   
sudo chown $(id -u):$(id -g) $HOME/.kube/config

Answer 2

Well, to answer your first question I think you have to do a few things to resolve your problem.

First, run the command given in this link : kubernetes.io/docs/setup/independent/create-cluster-kubeadm‌​/…

Complete with those commands :

• mkdir -p $HOME/.kube
• sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
• sudo chown $(id -u):$(id -g) $HOME/.kube/config

This admin.conf should be known to kubectl so as to work properly.

Answer 3

Please see this as a reference and maybe help you resolve your issue by exporting your certs:

kops export kubecfg "your cluster-name"
export KOPS_STATE_STORE=s3://"paste your S3 store"

Hope that will help.

Answer 4

From [kubernetes][1] official site:

1. Verify that the $HOME/.kube/config file contains a valid certificate, and regenerate a certificate

2. Unset the KUBECONFIG environment variable using:

   unset KUBECONFIG

   Or set it to the default KUBECONFIG location:

   export KUBECONFIG=/etc/kubernetes/admin.conf

3. Another workaround is to overwrite the existing kubeconfig for the “admin” user:

   mkdir $HOME/.kube
   sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
   sudo chown $(id -u):$(id -g) $HOME/.kube/config```


**Reference:** [official site link reference][2]

[1]: https://kubernetes.io/
[2]: https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/troubleshooting-kubeadm/

Answer 5

The above mentioned regular method does not work. I have tried to use the complete commands for a successful certificate. Please see the commands as follows.

$ sudo kubeadm reset
$ sudo swapoff -a 

$ sudo kubeadm init --pod-network-cidr=10.244.10.0/16 --kubernetes- 
  version "1.18.3"
$ sudo rm -rf /home/cm/.kube

$ mkdir -p $HOME/.kube
$ sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
$ sudo chown $(id -u):$(id -g) $HOME/.kube/config

$ sudo systemctl enable docker.service
$ sudo service kubelet restart

$ kubectl get nodes

Notes:

If the port refuses to be connected, please add the following command.

$ export KUBECONFIG=$HOME/admin.conf