<p>After removing Kubernetes 1.15 (master and worker node):</p>

<pre><code>kubeadm reset
apt-get purge kubeadm kubectl kubelet kubernetes-cni kube*
</code></pre>

<p>and removing all config files and installing again 1.17 getting this error while joining cluster:</p>

<pre><code>[kubelet-start] Downloading configuration for the kubelet from the "kubelet-config-1.15" ConfigMap in the kube-system namespace
error execution phase kubelet-start: configmaps "kubelet-config-1.15" is forbidden: User "system:bootstrap:fmhnus" cannot get resource "configmaps" in API group "" in the namespace "kube-system"
</code></pre>

<p>What did I miss and where?</p>

<p>Follow these steps to completely remove Kubernetes</p>

<pre><code>kubeadm reset
sudo apt-get purge kubeadm kubectl kubelet kubernetes-cni kube*   
sudo apt-get autoremove  
sudo rm -rf ~/.kube
</code></pre>

<p><code>kubeadm reset</code> un-configures the cluster made by kubernetes.</p>
