UBUNTU18+KVM+VAGRANT+KUBERNETES 4)HOW TO ADD WORKER NODE ON A CLUSTER

#This docu explain how to add worker node on a K8S cluster.

[vagrant@kubemaster ~]$ kubeadm token create
tfj754.wlscygdbg7bay497
[vagrant@kubemaster ~]$ kubeadm token list
TOKEN TTL EXPIRES USAGES DESCRIPTION EXTRA GROUPS
tfj754.wlscygdbg7bay497 23h 2018-08-26T10:06:48Z authentication,signing <none> system:bootstrappers:kubeadm:default-node-token


[vagrant@kubeworker3 ~]$ sudo -i
[root@kubeworker3 ~]# kubeadm join --token tfj754.wlscygdbg7bay497 10.1.0.2:6443
discovery: Invalid value: "": using token-based discovery without discoveryTokenCACertHashes can be unsafe. set --discovery-token-unsafe-skip-ca-verification to continue
[root@kubeworker3 ~]#


[vagrant@kubemaster ~]$ openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt | openssl rsa -pubin -outform der 2>/dev/null | \
> openssl dgst -sha256 -hex | sed 's/^.* //'
42e4571e6081c102d202ee6e3a2a2753a13f33ac1a463734fdff200cfb40d413
[vagrant@kubemaster ~]$


[root@kubeworker3 ~]# kubeadm join --token tfj754.wlscygdbg7bay497 10.1.0.2:6443 --discovery-token-ca-cert-hash sha256:42e4571e6081c102d202ee6e3a2a2753a13f33ac1a463734fdff200cfb40d413
[preflight] running pre-flight checks
 [WARNING RequiredIPVSKernelModulesAvailable]: the IPVS proxier will not be used, because the following required kernel modules are not loaded: [ip_vs ip_vs_rr ip_vs_wrr ip_vs_sh] or no builtin kernel ipvs support: map[ip_vs:{} ip_vs_rr:{} ip_vs_wrr:{} ip_vs_sh:{} nf_conntrack_ipv4:{}]
you can solve this problem with following methods:
 1. Run 'modprobe -- ' to load missing kernel modules;
2. Provide the missing builtin kernel ipvs support

I0825 10:20:22.768168 4841 kernel_validator.go:81] Validating kernel version
I0825 10:20:22.768442 4841 kernel_validator.go:96] Validating kernel config
[discovery] Trying to connect to API Server "10.1.0.2:6443"
[discovery] Created cluster-info discovery client, requesting info from "https://10.1.0.2:6443"
[discovery] Requesting info from "https://10.1.0.2:6443" again to validate TLS against the pinned public key
[discovery] Cluster info signature and contents are valid and TLS certificate validates against pinned roots, will use API Server "10.1.0.2:6443"
[discovery] Successfully established connection with API Server "10.1.0.2:6443"
[kubelet] Downloading configuration for the kubelet from the "kubelet-config-1.11" ConfigMap in the kube-system namespace
[kubelet] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[preflight] Activating the kubelet service
[tlsbootstrap] Waiting for the kubelet to perform the TLS Bootstrap...
[patchnode] Uploading the CRI Socket information "/var/run/dockershim.sock" to the Node API object "kubeworker3" as an annotation

This node has joined the cluster:
* Certificate signing request was sent to master and a response
 was received.
* The Kubelet was informed of the new secure connection details.

Run 'kubectl get nodes' on the master to see this node join the cluster.


[vagrant@kubemaster ~]$ kubectl get nodes
NAME STATUS ROLES AGE VERSION
kubemaster Ready master 12d v1.11.2
kubeworker1 Ready <none> 12d v1.11.2
kubeworker2 Ready <none> 12d v1.11.2
kubeworker3 NotReady <none> 56s v1.11.2



[vagrant@kubemaster ~]$ kubectl get nodes
NAME STATUS ROLES AGE VERSION
kubemaster Ready master 12d v1.11.2
kubeworker1 Ready <none> 12d v1.11.2
kubeworker2 Ready <none> 12d v1.11.2
kubeworker3 Ready <none> 2m v1.11.2