I'm trying to create aa k8s cluster but I'm struggling with a unexpected behavior.
I didn't have any problem to run kubeadm init on the master-node. So far so good
When I run the following command on the worker node:
kubeadm join [master-node-url]:6443 --token [generated-token-on-master] --discovery-token-ca-cert-hash sha256:[generated-sha256-on-master] I get the following logs
[preflight] Running pre-flight checks
[WARNING IsDockerSystemdCheck]: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "systemd". Please follow the guide at https://kubernetes.io/docs/setup/cri/
[WARNING SystemVerification]: this Docker version is not on the list of validated versions: 20.10.3. Latest validated version: 19.03and the command hangs.
Can you help me? What I'm missing? Thanks.
This is expected because docker version 20.x.x may cause some issues because k8s has not been tested agains this version.
You can solve it by installing docker version 19.03. Follow the guide from k8s docs https://kubernetes.io/docs/setup/production-environment/container-runtimes/#docker
In k8s docs you can also find the following note:
The Kubernetes release notes list which versions of Docker are compatible with that version of Kubernetes.
So you might also want to check the release notes and check which version is supported.