awels

Deploying KubeVirt on a single oVirt VM.

In this blog post we are exploring the possibilities of deploying Kube Virt on top of Open Shift which is running inside an oVirt VM. First we must prepare the environment. In my testing I created a VM with 4 cpus, 14G memory and a 100G disk. I then installed Centos 7.4 minimal on it. I also have nested virtualization enabled on my hosts, so any VMs I create can run VMs inside them. These instructions are specific to oVirt, however if you are running another virtualization platform that can nested virtualization this will also work.

For this example I chose to use a single VM for everything, but I could have done different VMs for my master/nodes/storage/etc, for simplicity I used a single VM.

Preparing the VM

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Getting started with storage

This document assumes you have a working development environment.

************************** THIS ONLY WORKS ON A SINGLE NODE ENVIRONMENT ****************************

Install hostPath storage class provisioner

Brazenly stolen from here as its more dynamic and flexible than my original solution.

awels

apiVersion: apps/v1
kind: Deployment
metadata:
  name: hostpath-provisioner
  labels:
    app: hostpath-provisioner
spec:
  selector:
    matchLabels:
      app: hostpath-provisioner

awels

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
 name: local
 annotations:
  storageclass.kubernetes.io/is-default-class: "true"
provisioner: kubernetes.io/no-provisioner
volumeBindingMode: WaitForFirstConsumer
reclaimPolicy: Delete
---

awels

Building Clusters with kubevirtci

One of the projects in the Kubevirt github organization is a project called kubevirtci. While this may sound like it’s the repo containing the Kubevirt CI system and scripts, that’s not completely accurate. We leverage kubevirtci for our CI process, but there’s more to the CI system than just this repo. Today, we’re not going to talk about the CI system in general, but instead we’re going to talk about the kubevirtci project, what it does, how it does it and why it’s pretty cool.

What it does

In short: Deploys a Kubernetes (or OpenShift) cluster using QEMU Virtual Machines, that run inside Docker containers. First a base image is provisioned, this image contains a stock a Kubernetes node. Then one or more of these images are deployed in the target environment to make up the cluster.

Provisioning

Building the Kubernetes Node virtual machine happens in several steps:

1. Use a Fedora cloud image.
2. Provision Kubernetes using Ansible onto that image.

awels

#!/bin/bash -e

function _kubectl(){
  kubectl "$@"
}

if [ -z $1 ]; then
    echo "node to export not provided"
    exit 1
fi

awels

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: test
spec:
  accessModes:
    - ReadWriteOnce
  storageClassName: hostpath-csi
  resources:
    requests:

awels

[awels@awels kubevirt]$ k get vmi
selecting docker as container runtime
NAME        AGE   PHASE        IP    NODENAME   READY
vm-cirros   3s    Scheduling                    False
[awels@awels kubevirt]$ k describe vmi vm-cirros
selecting docker as container runtime
Name:         vm-cirros
Namespace:    default
Labels:       kubevirt.io/nodeName=node01
              kubevirt.io/vm=vm-cirros

awels

apiVersion: v1
kind: Secret
metadata:
  name: secret-headers
  namespace: elasticsearch-demo-app
stringData:
  token: "x-kubevirt-export-token:d2URaNJNFBvae3786OlT"