-como saber si el OS tiene cluster corriendo o iniciados


---------------------------------------------------------------------------init clusters
Initialize the control plane(cp)
root@cp:# kubeadm init --config=kubeadm-crio.yaml --upload-certs  | tee kubeadm-init.out   # Save output for future review

Success messages:

			Your Kubernetes control-plane has initialized successfully!
			
			To start using your cluster, you need to run the following as a regular user:
			
			  mkdir -p $HOME/.kube
			  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
			  sudo chown $(id -u):$(id -g) $HOME/.kube/config
			
			Alternatively, if you are the root user, you can run:
			
			  export KUBECONFIG=/etc/kubernetes/admin.conf
			
			You should now deploy a pod network to the cluster.
			Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
			  https://kubernetes.io/docs/concepts/cluster-administration/addons/
			
			You can now join any number of the control-plane node running the following command on each as root:
			
			  kubeadm join k8scp:6443 --token abcdef.0123456789abcdef \
			        --discovery-token-ca-cert-hash sha256:6cff953cb5b537a8eef9c32535dbe3db9deca2884f8000ac4e59c9c11854c85b \
			        --control-plane --certificate-key 733803415367b636ee688ae7b2cbda2b61f1d838366f148092efd8f329cec114
			
			Please note that the certificate-key gives access to cluster sensitive data, keep it secret!
			As a safeguard, uploaded-certs will be deleted in two hours; If necessary, you can use
			"kubeadm init phase upload-certs --upload-certs" to reload certs afterward.
			
			Then you can join any number of worker nodes by running the following on each as root:
			
			kubeadm join k8scp:6443 --token abcdef.0123456789abcdef \
			        --discovery-token-ca-cert-hash sha256:6cff953cb5b537a8eef9c32535dbe3db9deca2884f8000ac4e59c9c11854c85b




---------------------------------------------------------------------------join workers and manage tokens

--- view current tokens

    student@cp:$ sudo kubeadm token list

--- create new tokens
 
    student@cp:$ sudo kubeadm token create

--- Create and use a Discovery Token CA Cert Hash created from the cp to ensure the node joins the 
    cluster in a securemanner. Run this on the cp node or wherever you have a copy of the CA file.
    see /etc/kubernetes/pki
    
    
    student@cp:$ openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt | openssl rsa -pubin -outform der 2>/dev/null | openssl dgst -sha256 -hex | sed 's/ˆ.* //'
    
---On the worker node add a local DNS alias for the cp server.
   
   root@worker:# vim /etc/hosts
   
   10.128.0.3 k8scp    #<-- Add this line
   
--Use the token and hash, in this case assha256:long-hashto join the cluster from thesecond/workernode.
  root@worker:# kubeadm join --token <tokenId> k8scp:6443 --discovery-token-ca-cert-hash sha256:<theHash obtained from openssl x509 -pubkey...>
  
  Ej.
    root@worker:# kubeadm join --token 27eee4.6e66ff60318da929 k8scp:6443 --discovery-token-ca-cert-hash sha256:6d541678b05652e1fa5d43908e75e67376e994c3483d6683f2a18673e5d2a1b0
                  kubeadm join --token hofgbm.vh8coc1nxfx9zdb4 k8scp:6443 --discovery-token-ca-cert-hash sha256:e56c42367d19b855e8405abcac82150fc9aff740b07084a787e6575541921d3c
                  kubeadm join --token o0klwp.jsvzn7vvxmg004oi k8scp:6443 --discovery-token-ca-cert-hash sha256:bd85757824fd126d92e63ee0dfc2ded8ef4aba73e44e34c127ee37c7affd59e3
                  
                  
                  
------------------------------------------------------------------------upgrade plan
Use the upgrade plan argument to check the existing cluster and then update the software.

student@cp:~$ sudo kubeadm upgrade plan





-----------------------------------------------------------------to actually upgrade the software.
student@cp:~$ sudo kubeadm upgrade apply <v1.22.1>