KubeVirt charm

KubeVirt is a a vm-based workload system built on Kubernetes.

KubeVirt technology addresses the needs of development teams that have adopted or want to adopt Kubernetes but possess existing Virtual Machine-based workloads that cannot be easily containerised. More specifically, the technology provides a unified development platform where developers can build, modify, and deploy applications residing in both Application Containers as well as Virtual Machines in a common, shared environment.

This work is based on the upstream project kubevirt.io.

Deploying the kubevirt charms

Prerequisites

• The kubevirt charm is deployed as a subordinate to the Kubernetes Worker
• These instructions assume you have a cluster created with Juju and named charmed-kubernetes.
  • Please adjust the commands given appropriately if you have used a different name.
• kubevirt requires that the control-plane allows for privileged containers:

  juju config kubernetes-control-plane allow-privileged=true
  

• Optional If the worker machines are themselves VMs, you will be creating VMs in VMs or (nested virtualisation).
  • The charm will enable software-emulation for virtualisation if /dev/kvm is not detected on any one worker node.

Deploying

The charm is deployed as a subordinate on the workers and will install qemu on each worker unit where it is deployed. The most recent release the charm supports will be installed into the cluster after which virtctl can be used to launch VMs into the cluster.

juju deploy kubevirt --trust
juju integrate kubevirt:juju-info kubernetes-worker
juju integrate kubevirt:kube-control kubernetes-control-plane

Configuration

operator-release

• defaults: auto

• Specifies the version of KubeVirt as defined by the release tags of https://github.com/kubevirt/kubevirt/releases

  The charm has a fixed set of supported versions which can be queried with:

  juju run kube-virt/leader list-releases
  

software-emulation

• defaults: unset
• Whether or not to allow software-emulation of VMs
  • true: allows such behavior
  • false: disallows such behavior
  • unset: automatically determined by the group of units

pvc-tolerate-less-space-up-to-percent

• defaults: 10
• Since not every storage provisioner provides volumes with the exact usable amount of space as requested (e.g. due to filesystem overhead), KubeVirt tolerates up to N% less available space.