kgoldbla / ocm-kubevirt-samples

ocm-kubevirt-samples

This repo contains sample kubevirt resources for deployment in Kubernetes or OpenShift clusters.

Using in OpenShift

Use ACM console to deploy the VM, enable DR or delete the VM.

Deploying the VM

1. Create new application using:

   • repo: this repo URL
   • branch: main
   • path: one of the vm-*-odr-* directories

2. To enable DR assign DR Policy

Testing DR

Use ACM console to perform failover or relocate actions.

Deleting the VM

Use ACM console to delete the application.

Using in Kubernetes

In Kubernetes you need to deploy the VM and DR resources using the command line tools or API.

Adding your SSH key

If you want to inject your SSH key into the VM, you need to replace the included SSH public key with your own public key.

1. Fork this repo in github
2. Replace the contents of the vm-standalone-pvc-k8s/test_rsa.pub with your public key (e.g. ~/.ssh/id_rsa.pub)
3. Update channel/channel.yaml to point to your repository (e.g. https://github.com/my-github-user/ocm-kubevirt-samples.git)
4. If you are not using the main branch update subscription/subscription.yaml to point to the right branch.

Deploying the channel

Deploy the channel to introduce this repo to OCM:

kubectl apply -k channel --context hub

Deploying the VM subscription

To start the VM deploy the subscription:

kubectl apply -k subscription --context hub

The subscription starts the VM vm-standalone-pvc-k8s on one of the clusters in the default clusterset.

The subscription is optimized for Ramen minikube based test environment. To use in another setup you may need to modify the resources.

Enabling DR for the VM

To allow Ramen to protect the VM, you need to disable OCM scheduling by adding an annotation to the VM placement:

kubectl annotate placement kubevirt-placement \
    cluster.open-cluster-management.io/experimental-scheduling-disable=true \
    --namespace kubevirt-sample \
    --context hub

Deploy the DR resources to enable DR:

kubectl apply -k dr --context hub

At this point Ramen controls the VM, and you can test DR actions.

Failing over to another cluster

In case of disaster you can force the VM to run on the other cluster. The VM will start on the other cluster using the data from the last replication. Data since the last replication is lost.

Patch the VM DRPlacementControl resource to set action and failoverCluster:

kubectl patch drpc kubevirt-drpc \
    --patch '{"spec": {"action": "Failover", "failoverCluster": "dr2"}}' \
    --type merge \
    --namespace kubevirt-sample \
    --context hub

The VM will start on the failover cluster ("dr2"), and the instance running on the original cluster ("dr1") will be terminated.

To wait until the operation is completed use:

kubectl wait drpc kubevirt-drpc \
    --for condition=PeerReady \
    --namespace kubevirt-sample \
    --timeout 5m \
    --context hub

Relocating to another cluster

To move the VM back to the original cluster after a disaster you can use the Relocate action. The VM will be terminated on the current cluster, and started on the other cluster. No data is lost during this operation.

Patch the VM DRPlacementControl resource to set action and if needed, preferredCluster.

kubectl patch drpc kubevirt-drpc \
    --patch '{"spec": {"action": "Relocate", "preferredCluster": "dr1"}}' \
    --type merge \
    --namespace kubevirt-sample \
    --context hub

The VM will terminate on the current cluster and will start on the preferred cluster.

To wait until the operation is completed, wait until the drpc phase is Relocated:

kubectl wait drpc kubevirt-drpc \
    --for jsonpath='{.status.phase}=Relocated' \
    --namespace kubevirt-sample \
    --timeout 5m \
    --context hub

Finally wait for the PeerReady condition:

kubectl wait drpc kubevirt-drpc \
    --for condition=PeerReady \
    --namespace kubevirt-sample \
    --timeout 5m \
    --context hub

Disable DR for the VM

Delete the dr resources to disable DR:

kubectl delete -k dr --context hub

Enable OCM scheduling again by deleting the placement annotation we added before:

kubectl annotate placement kubevirt-placement \
    cluster.open-cluster-management.io/experimental-scheduling-disable- \
    --namespace kubevirt-sample \
    --context hub

At this point OCM controls the VM and the storage used for replicating the VM data on the DR clusters will be reclaimed.

Undeploying the VM

Delete the subscription to stop and delete the VM:

kubectl delete -k subscription --context hub

Delete the channel

When done you can delete the channel:

kubectl delete -k channel --context hub