The KubeVirt cloud-provider allows you to use KubeVirt and Kubernetes as a "cloud" to run Kubernetes clusters on top. This project contains the kubevirt-cloud-controller-manager, an implementation of the cloud controller manager (see Concepts Underlying the Cloud Controller Manager for more details).

The KubeVirt cloud-provider allows a Kubernetes cluster running in KubeVirt VMs (tenant cluster) to interact with KubeVirt and Kubernetes (infrastructure cluster) to provision, manage and clean up resources. For example, the cloud-provider ensures that zone and region labels of nodes in the tenant cluster are set based on the zone and region of the KubeVirt VMs in the infrastructure cluster. The cloud-provider also ensures tenant cluster services of type LoadBalancer are properly exposed through services in the UnderKube.

In order to have the LoadBalancer logic working in the "tenant KubeVirt cluster, user must make sure the the KubeVirt VMs, used for the tenant cluster nodes, are created with the following labels:

cluster.x-k8s.io/cluster-name: <tenant-cluster-name>
cluster.x-k8s.io/role: worker

Those labels are used by the infra cluster services as a NodeSelector - traffic from the infra cluster services created for the tenant cluster is redirected into VM with those Labels

See Running cloud-controller-manager for general information on how to configure your tenant cluster to run kubevirt-cloud-controller-manager. You can find example manifests for kubevirt-cloud-controller-manager in the manifests directory for static Pod, Deployment and DaemonSet configurations.

To get it to run, you'll need to provide a kubeconfig for the infrastructure cluster to the kubevirt-cloud-controller-manager configuration. The configuration should contain an kubeconfig key, like in the following example:

cat /etc/kubernetes/cloud/config

Output:

kubeconfig: <infraKubeConfigPath>
loadBalancer:
  creationPollInterval: 5
  creationPollTimeout: 60

With make image you can build a Docker image containing kubevirt-cloud-controller-manager.

First create a cloud config file in the project directory

touch dev/cloud-config

Next add a kubeconfig path to the cloud-config file. The kubeconfig must point to the infrastructure cluster where KubeVirt is installed.

kubeconfig: <infraKubeConfigPath>

For more configuration options look at the cloud configuration

Build kubevirt-cloud-controller-manager using make build. It will put the finished binary in bin/kubevirt-cloud-controller-manager.

Run the following command:

bin/kubevirt-cloud-controller-manager --kubeconfig <path-to-tenant-cluster-kubeconfig> --cloud-config dev/cloud-config