<p>I have set up my master node and I am trying to join a worker node as follows:</p>

<pre><code>kubeadm join 192.168.30.1:6443 --token 3czfua.os565d6l3ggpagw7 --discovery-token-ca-cert-hash sha256:3a94ce61080c71d319dbfe3ce69b555027bfe20f4dbe21a9779fd902421b1a63
</code></pre>

<p>However the command hangs forever in the following state:</p>

<pre><code>[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/
</code></pre>

<p>Since this is just a warning, why does it actually fails?</p>

<p><strong>edit</strong>: I noticed the following in my <code>/var/log/syslog</code></p>

<pre><code>Mar 29 15:03:15 ubuntu-xenial kubelet[9626]: F0329 15:03:15.353432    9626 server.go:193] failed to load Kubelet config file /var/lib/kubelet/config.yaml, error failed to read kubelet config file "/var/lib/kubelet/config.yaml", error: open /var/lib/kubelet/config.yaml: no such file or directory
Mar 29 15:03:15 ubuntu-xenial systemd[1]: kubelet.service: Main process exited, code=exited, status=255/n/a
Mar 29 15:03:15 ubuntu-xenial systemd[1]: kubelet.service: Unit entered failed state.
</code></pre>

<p>First if you want to see more detail when your worker joins to the master use:</p>

<pre><code>kubeadm join 192.168.1.100:6443 --token m3jfbb.wq5m3pt0qo5g3bt9     --discovery-token-ca-cert-hash sha256:d075e5cc111ffd1b97510df9c517c122f1c7edf86b62909446042cc348ef1e0b --v=2
</code></pre>

<p>Using the above command I could see that my worker could not established connection with the master, so i just stoped the firewall:</p>

<pre><code>systemctl stop firewalld 
</code></pre>
