Devconf.cz 2023

In this talk, we will explore a scenario where a large 5G Telco application requires an OCP cluster with three masters and at least two workers. However, the only hardware resource available is a single (but large) baremetal server. To solve this non-trivial DevOps task, we propose setting up an OCP cluster on virtual machines connected by virtual networks using the Libvirt library's API. We will demonstrate how to create and start VMs for workers, masters, and provisioners, and explain the need for nested KVM. We will also discuss the required network setup, demonstrating a simple combination of baremetal and provisioning networks to provide both in-cluster and outside connectivity. We will showcase an open-source code managed by our team that automates all these steps, as well as the generation of inventories for the OCP installation and the OCP deployment itself. Finally, we will provide a small demo of an automated OCP-on-Libvirt installation ready for a test server or a home lab.