The virtualization module: configuration examples

Getting a list of available images

Deckhouse comes with several base images that you can use to create virtual machines. To get a list of them, run:

kubectl get cvmi

Example of the output:

NAME           AGE
alpine-3.16    30d
centos-7       30d
centos-8       30d
debian-9       30d
debian-10      30d
fedora-36      30d
rocky-9        30d
ubuntu-16.04   30d
ubuntu-18.04   30d
ubuntu-20.04   30d
ubuntu-22.04   30d

Creating a virtual machine

The minimal resource for creating a virtual machine looks like this:

apiVersion: deckhouse.io/v1alpha1
kind: VirtualMachine
metadata:
  name: vm100
  namespace: default
spec:
  running: true
  resources:
    memory: 512M
    cpu: "1"
  userName: ubuntu
  sshPublicKey: "ssh-rsa asdasdkflkasddf..."
  bootDisk:
    source:
      kind: ClusterVirtualMachineImage
      name: ubuntu-22.04
    size: 10Gi
    storageClassName: linstor-thindata-r2
    autoDelete: true

In the bootDisk parameter, you can also specify the name of an existing virtual machine disk. In this case, it will be connected to it directly without performing a clone operation. This parameter also defines the name of the disk to be created. If it is not specified, the default template is <vm_name>-boot.

An example:

bootDisk:
  name: "myos"
  size: 10Gi
  autoDelete: false

The autoDelete parameter allows you to specify whether the disk should be deleted after deleting the virtual machine.

Working with IP addresses

Each virtual machine is assigned a separate IP address, which it uses throughout its life.
For this, the IPAM (IP Address Management) mechanism is used, which represents two resources: VirtualMachineIPAddressClaim and VirtualMachineIPAddressLease.

While VirtualMachineIPAddressLease is a clustered resource and reflects the fact that the address for the virtual machine has been issued. The VirtualMachineIPAddressClaim is a user resource and is used to request such an address. By creating a VirtualMachineIPAddressClaim you can request the desired IP address for the virtual machine.

An example:

apiVersion: deckhouse.io/v1alpha1
kind: VirtualMachineIPAddressClaim
metadata:
  name: vm100
  namespace: default
spec:
  address: 10.10.10.10
  static: true

The desired IP address should be in the range of networks defined in the vmCIDRs parameter of the module configuration and should not be occupied by any other virtual machine.

If the VirtualMachineIPAddressClaim was not created by the user beforehand, then it will be created automatically with the virtual machine creation. In this case, the next free IP address in the vmCIDRs range will be assigned.

When deleting the virtual machine, the VirtualMachineIPAddressClaim associated with it will also be deleted. To prevent this from happening, you need to mark such an IP address as static. To do this, you need to edit the generated VirtualMachineIPAddressClaim and set the static: true field in it. After deleting the VM, the static IP address remains reserved in the namespace.

Use the following command to get the list of all issued IP addresses:

kubectl get vmip

Example of the output:

NAME    ADDRESS       STATIC   STATUS   VM      AGE
vm1     10.10.10.0    false    Bound    vm1     9d
vm100   10.10.10.10   true     Bound    vm100   172m

Just delete the VirtualMachineIPAddressClaim resource to free up the IP address:

kubectl delete vmip vm100

VirtualMachineIPAddressClaim is named as the virtual machine by default, but it is possible to pass any other arbitrary name by using the ipAddressClaimName parameter.

Creating disks for storing persistent data

Additional disks should be created manually:

En example:

apiVersion: deckhouse.io/v1alpha1
kind: VirtualMachineDisk
metadata:
  name: mydata
spec:
  storageClassName: linstor-data
  size: 10Gi

It is possible to create a disk from an existing image, just specify the corresponding ClusterVirtualMachineImage in the source parameter.

An example:

source:
  kind: ClusterVirtualMachineImage
  name: centos-7

Attaching additional disks is done using the diskAttachments parameter.

An example:

apiVersion: deckhouse.io/v1alpha1
kind: VirtualMachine
metadata:
  name: vm100
  namespace: default
spec:
  running: true
  resources:
    memory: 512M
    cpu: "1"
  userName: admin
  sshPublicKey: "ssh-rsa asdasdkflkasddf..."
  bootDisk:
    source:
      kind: ClusterVirtualMachineImage
      name: ubuntu-22.04
    size: 10Gi
    storageClassName: linstor-fast
    autoDelete: true
  diskAttachments:
  - name: mydata
    bus: virtio

Using cloud-init

Optionally, you can pass the cloud-init configuration in the cloud-init parameter.

An example:

apiVersion: deckhouse.io/v1alpha1
kind: VirtualMachine
metadata:
  name: vm1
  namespace: default
spec:
  running: true
  resources:
    memory: 512M
    cpu: "1"
  userName: admin
  sshPublicKey: "ssh-rsa asdasdkflkasddf..."
  bootDisk:
    source:
      kind: ClusterVirtualMachineImage
      name: ubuntu-22.04
    size: 10Gi
  cloudInit:
    userData: |-
      password: hackme
      chpasswd: { expire: False }

The cloud-init configuration can also be saved in Secret and passed to the virtual machine like this:

cloudInit:
  secretRef:
    name: my-vmi-secret