Updating and deletion¶
Updating KubeVirt Control Plane¶
Zero downtime rolling updates are supported starting with release
v0.17.0
onward. Updating from any release prior to the KubeVirt
v0.17.0
release is not supported.
Note: Updating is only supported from N-1 to N release.
Updates are triggered one of two ways.
-
By changing the imageTag value in the KubeVirt CR's spec.
For example, updating from
v0.17.0-alpha.1
tov0.17.0
is as simple as patching the KubeVirt CR with theimageTag: v0.17.0
value. From there the KubeVirt operator will begin the process of rolling out the new version of KubeVirt. Existing VM/VMIs will remain uninterrupted both during and after the update succeeds. -
Or, by updating the kubevirt operator if no imageTag value is set.
When no imageTag value is set in the kubevirt CR, the system assumes that the version of KubeVirt is locked to the version of the operator. This means that updating the operator will result in the underlying KubeVirt installation being updated as well.
The first way provides a fine granular approach where you have full control over what version of KubeVirt is installed independently of what version of the KubeVirt operator you might be running. The second approach allows you to lock both the operator and operand to the same version.
Newer KubeVirt may require additional or extended RBAC rules. In this
case, the #1 update method may fail, because the virt-operator present
in the cluster doesn't have these RBAC rules itself. In this case, you
need to update the virt-operator
first, and then proceed to update
kubevirt. See this issue for more
details.
Updating KubeVirt Workloads¶
Workload updates are supported as an opt in feature starting with v0.39.0
By default, when KubeVirt is updated this only involves the control plane components. Any existing VirtualMachineInstance (VMI) workloads that are running before an update occurs remain 100% untouched. The workloads continue to run and are not interrupted as part of the default update process.
It's important to note that these VMI workloads do involve components such as libvirt, qemu, and virt-launcher, which can optionally be updated during the KubeVirt update process as well. However that requires opting in to having virt-operator perform automated actions on workloads.
Opting in to VMI updates involves configuring the workloadUpdateStrategy
field on the KubeVirt CR. This field controls the methods virt-operator will
use to when updating the VMI workload pods.
There are two methods supported.
LiveMigrate: Which results in VMIs being updated by live migrating the virtual machine guest into a new pod with all the updated components enabled.
**Evict: ** Which results in the VMI's pod being shutdown. If the VMI is
controlled by a higher level VirtualMachine object with runStrategy: always
,
then a new VMI will spin up in a new pod with updated components.
The least disruptive way to update VMI workloads is to use LiveMigrate. Any VMI workload that is not live migratable will be left untouched. If live migration is not enabled in the cluster, then the only option available for virt-operator managed VMI updates is the Evict method.
Example: Enabling VMI workload updates via LiveMigration
apiVersion: kubevirt.io/v1
kind: KubeVirt
metadata:
name: kubevirt
namespace: kubevirt
spec:
imagePullPolicy: IfNotPresent
workloadUpdateStrategy:
workloadUpdateMethods:
- LiveMigrate
Example: Enabling VMI workload updates via Evict with batch tunings
The batch tunings allow configuring how quickly VMI's are evicted. In large clusters, it's desirable to ensure that VMI's are evicted in batches in order to distribute load.
apiVersion: kubevirt.io/v1
kind: KubeVirt
metadata:
name: kubevirt
namespace: kubevirt
spec:
imagePullPolicy: IfNotPresent
workloadUpdateStrategy:
workloadUpdateMethods:
- Evict
batchEvictionSize: 10
batchEvictionInterval: "1m"
Example: Enabling VMI workload updates with both LiveMigrate and Evict
When both LiveMigrate and Evict are specified, then any workloads which are live migratable will be guaranteed to be live migrated. Only workloads which are not live migratable will be evicted.
apiVersion: kubevirt.io/v1
kind: KubeVirt
metadata:
name: kubevirt
namespace: kubevirt
spec:
imagePullPolicy: IfNotPresent
workloadUpdateStrategy:
workloadUpdateMethods:
- LiveMigrate
- Evict
batchEvictionSize: 10
batchEvictionInterval: "1m"
Deleting KubeVirt¶
To delete the KubeVirt you should first to delete KubeVirt
custom
resource and then delete the KubeVirt operator.
$ export RELEASE=v0.17.0
$ kubectl delete -n kubevirt kubevirt kubevirt --wait=true # --wait=true should anyway be default
$ kubectl delete apiservices v1.subresources.kubevirt.io # this needs to be deleted to avoid stuck terminating namespaces
$ kubectl delete mutatingwebhookconfigurations virt-api-mutator # not blocking but would be left over
$ kubectl delete validatingwebhookconfigurations virt-operator-validator # not blocking but would be left over
$ kubectl delete validatingwebhookconfigurations virt-api-validator # not blocking but would be left over
$ kubectl delete -f https://github.com/kubevirt/kubevirt/releases/download/${RELEASE}/kubevirt-operator.yaml --wait=false
Note: If by mistake you deleted the operator first, the KV custom resource will get stuck in the
Terminating
state, to fix it, delete manually finalizer from the resource.Note: The
apiservice
and thewebhookconfigurations
need to be deleted manually due to a bug.$ kubectl -n kubevirt patch kv kubevirt --type=json -p '[{ "op": "remove", "path": "/metadata/finalizers" }]'