Overview of Kubernetes#

Zergaw Kubernetes service provides the functionality of running and managing Kubernetes clusters. Highly available, scalable Kubernetes clusters can be created to run containerized deployments without having to set up Kubernetes on each container node manually. The service will automatically provision the desired number of Instances as per cluster size using the binaries corresponding to the provided Kubernetes version. Additionally, the service provides the functionality to upgrade and scale clusters. Running clusters can be upgraded to a newer minor or patch Kubernetes version at a time. Running clusters can also be scaled up or down based on the number of worker nodes provided and to the service offering used by each node.

Note

  • Multi-control nodes, HA cluster can be created for Kubernetes version 1.16 and above only.

This is done by Kubernetes Service plugin that adds Kubernetes integration to Zergaw CloudStack. For deployment and setup of Kubernetes on cluster nodes, the plugin uses the Kubernetes tool, ‘kubeadm’. kubeadm is the command-line tool for easily provisioning a secure Kubernetes cluster on top of physical or cloud servers or Instances. Under the hood, control node(s) of the cluster starts a Kubernetes cluster using kubeadm init command with a custom token, and worker nodes join this Kubernetes cluster using kubeadm join command with the same token. To access the Kubernetes dashboard securely, the plugin provides access to kubeconfig file data which uses the Kubernetes tool kubectl to run a local proxy and thereby access the dashboard. More about kubectl here: https://kubernetes.io/docs/reference/kubectl/overview/ The service allows creation of Kubernetes clusters using the UI or API. Both UI and API provide the ability to list, delete, scale, upgrade, stop and start these clusters.

The Kubernetes service provides the functionality to manage multiple supported Kubernetes versions. Management can be via both UI and API. A supported version corresponds to a specific Kubernetes version for which an ISO has been uploaded.