kubeadm-dind-cluster or kind

Even though it was recently retired in favour of kind (https://kind.sigs.k8s.io/kubeadm-dind (https://github.com/kubernetes-retired/kubeadm-dind-cluster) is still a great way to run a kubernetes cluster locally on laptop (in my case it is MacBook). It’s main limitation is that it supports v1.14.1, while kind supports v1.15.3 (though yesterday v1.16 version got released). Both rely on the same principle that nodes are not baremetal nodes nor VM, they are plain docker containers.  Then kubeadm is used to deploy k8s clusters on docker-based k8s cluster. System pods as well as user pods run as embedded containers inside docker container hosts (hence dind = docker-in-docker)

Yet with kubeadm-dind-cluster you can easily switch between CNI plugins, and it works between Docker for Desktop restarts and OS reboots.

Switching between CNI plugins is as easy as modifying inside an install script the following variable:

Main issue with kind is that OS reboot (not necessarily docker restart) causes originally assigned IPs to docker containers acting as k8s nodes to be changed. Hence after creating a cluster, making some configuration changes, or deploying pods etc we are forced to redo the job. Root cause of the problem is that docker doesn’t maintain originally assigned IPs to containers across docker restarts/OS reboots – at least it is not forced to do it (https://github.com/moby/moby/issues/2801). It is possible to assign static IPs to containers when starting containers with docker run. Unfortunately kind does not offer such option (for now). Issue is tracked at: https://github.com/kubernetes-sigs/kind/issues/148

All in all, when you want to practise with k8s (multi-node) on your laptop kubeadm-dind-cluster. kind is a very near future when it is made stable across docker restarts. 

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