FAQ | Deckhouse modules

The functionality of the module might change, but the main features will remain. Compatibility with future versions is guaranteed, but might require additional migration steps.

How to install an operating system in a virtual machine from an iso-image?

Let’s consider installing an operating system in a virtual machine from an iso-image, using Windows OS installation as an example.

To install the OS we will need an iso-image of Windows OS. We need to download it and publish it on some http-service available from the cluster.

Let’s create an empty disk for OS installation:

apiVersion: virtualization.deckhouse.io/v1alpha2
kind: VirtualDisk
metadata:
  name: win-disk
  namespace: default
spec:
  persistentVolumeClaim:
    size: 100Gi
    storageClassName: local-path

Let’s create resources with iso-images of Windows OS and virtio drivers:

apiVersion: virtualization.deckhouse.io/v1alpha2
kind: ClusterVirtualImage
metadata:
  name: win-11-iso
spec:
  dataSource:
    type: HTTP
    http:
      url: "http://example.com/win11.iso"

apiVersion: virtualization.deckhouse.io/v1alpha2
kind: ClusterVirtualImage
metadata:
  name: win-virtio-iso
spec:
  dataSource:
    type: HTTP
    http:
      url: "https://fedorapeople.org/groups/virt/virtio-win/direct-downloads/stable-virtio/virtio-win.iso"

Create a virtual machine:

apiVersion: virtualization.deckhouse.io/v1alpha2
kind: VirtualMachine
metadata:
  name: win-vm
  namespace: default
  labels:
    vm: win
spec:
  virtualMachineClassName: generic
  runPolicy: Manual
  osType: Windows
  bootloader: EFI
  cpu:
    cores: 6
    coreFraction: 50%
  memory:
    size: 8Gi
  enableParavirtualization: true
  blockDeviceRefs:
    - kind: ClusterVirtualImage
      name: win-11-iso
    - kind: ClusterVirtualImage
      name: win-virtio-iso
    - kind: VirtualDisk
      name: win-disk

Once the resource is created, the virtual machine will be started. You need to connect to it and use the graphical wizard to add the virtio drivers and perform the OS installation.

d8 v vnc -n default win-vm

After the installation is complete, shut down the virtual machine.

Next, modify the VirtualMachine resource and apply the changes:

spec:
  # ...
  runPolicy: AlwaysOn
  # ...
  blockDeviceRefs:
    # remove all ClusterVirtualImage resources with iso disks from this section
    - kind: VirtualDisk
      name: win-disk

How to provide windows answer file(Sysprep)

To provide Sysprep ability it’s necessary to define in virtual machine with SysprepRef provisioning. Set answer files (typically named unattend.xml or autounattend.xml) to secret to perform unattended installations of Windows. You can also specify here other files in base64 format (customize.ps1, id_rsa.pub, …) that you need to successfully execute scripts inside the answer file.

First, create sysprep secret:

apiVersion: v1
kind: Secret
metadata:
  name: sysprep-config
data:
  unattend.xml: XXXx # base64 of answer file
type: "provisioning.virtualization.deckhouse.io/sysprep"

Then create a virtual machine with unattended installation:

apiVersion: virtualization.deckhouse.io/v1alpha2
kind: VirtualMachine
metadata:
  name: win-vm
  namespace: default
  labels:
    vm: win
spec:
  virtualMachineClassName: generic
  provisioning:
    type: SysprepRef
    sysprepRef:
      kind: Secret
      name: sysprep-config
  runPolicy: AlwaysOn
  osType: Windows
  bootloader: EFI
  cpu:
    cores: 6
    coreFraction: 50%
  memory:
    size: 8Gi
  enableParavirtualization: true
  blockDeviceRefs:
    - kind: ClusterVirtualImage
      name: win-11-iso
    - kind: ClusterVirtualImage
      name: win-virtio-iso
    - kind: VirtualDisk
      name: win-disk

How to redirect traffic to a virtual machine

Since the virtual machine runs in a Kubernetes cluster, the forwarding of network traffic to it is done similarly to the forwarding of traffic to the pods.

To do this, you just need to create a service with the required settings.

Suppose we have a virtual machine with http service published on port 80 and the following set of labels:

apiVersion: virtualization.deckhouse.io/v1alpha2
kind: VirtualMachine
metadata:
  name: web
  labels:
    vm: web
spec: ...

In order to direct network traffic to port 80 of the virtual machine - let’s create a service:

apiVersion: v1
kind: Service
metadata:
  name: svc-1
spec:
  ports:
    - name: http
      port: 8080
      protocol: TCP
      targetPort: 80
  selector:
    app: old

We can change virtual machine label values on the fly, i.e. changing labels does not require restarting the virtual machine, which means that we can configure network traffic redirection from different services dynamically:

Let’s imagine that we have created a new service and want to redirect traffic to our virtual machine from it:

apiVersion: v1
kind: Service
metadata:
  name: svc-2
spec:
  ports:
    - name: http
      port: 8080
      protocol: TCP
      targetPort: 80
  selector:
    app: new

By changing the labels on the virtual machine, we will redirect network traffic from the svc-2 service to it

metadata:
  labels:
    app: old

How to increase the DVCR size

To increase the disk size for DVCR, you must set a larger size in the virtualization module configuration than the current size.

Check the current dvcr size:

kubectl get mc virtualization -o jsonpath='{.spec.settings.dvcr.storage.persistentVolumeClaim}''
#Output
{“size”:“58G”,“storageClass”:“linstor-thick-data-r1”}

Set the size:

kubectl patch mc virtualization \.
  --type merge -p '{“spec”: { “settings”: { “dvcr”: { “storage”: { “persistentVolumeClaim”: {“size”: “59G”}}}}}}''

#Output
moduleconfig.deckhouse.io/virtualization patched

Check the resizing:

kubectl get mc virtualization -o jsonpath='{.spec.settings.dvcr.storage.persistentVolumeClaim}'
#Output
{“size”:“59G”,“storageClass”:“linstor-thick-data-r1”}

kubectl get pvc dvcr -n d8-virtualization
#Output
NAME STATUS STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE
dvcr Bound pvc-6a6cedb8-1292-4440-b789-5cc9d15bbc6b 57617188Ki RWO linstor-thick-data-r1 7d