I'm Doing some homework ( linuxacademy tutorial ) with kubernetes ( 1 masters and 2 nodes ) Trying add my node1 using command kubeadm join on the node.
The command is pending without any error or result. I have tried on the node2 and I have the exact same result. I must kill the process with ctrl+c to exit
[root@K8SNode2 rbo]# kubeadm join 192.168.1.43:6443 --token 9jh998.01jsgbnvsg9373ix \
> --discovery-token-ca-cert-hash sha256:60df8024a4ee96018136424af429c5c16ffd15805 53128c83d4fc4861829197f
[preflight] Running pre-flight checks
[WARNING SystemVerification]: this Docker version is not on the list of valid ated versions: 19.03.1. Latest validated version: 18.09
running on CentOs7 minimal, installation on master seems good
[rbo@K8SMaster ~]$ kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8smaster Ready master 8h v1.15.3Thaks for help
So, we found the issue wasn't related to unsupported Docker version but to missing Firewalld open port 6443 on Master node: you can solve it using the simple command firewall-cmd --permanent --add-port=6443/tcp along with a firewall-cmd --reload.
After that, the node joined as expected but <none> role is attached and that's expected: you have to follow this solution in order to mark the node as worker using the key-value label node.kubernetes.io/role=worker