Skip to content

Cluster node template

The note template in the cluster section of the configuration defines the properties of all nodes in the cluster. This includes the properties of the operating system (OS), DNS, and virtual machine user.

Configuration🔗︎

Virtual machine user🔗︎

v2.0.0   Default: k8s

The user property defines the name of the passwordless user created on each virtual machine. It is used to access the virtual machines during cluster configuration. If the user property is omitted, a user named k8s is created on all virtual machines. This user can also be used later to access each virtual machine via SSH.

cluster:
  nodeTemplate:
    user: kubitect

Operating system (OS)🔗︎

OS distribution🔗︎

v2.1.0   Default: ubuntu

The operating system for virtual machines can be specified in the node template. Currently, either Ubuntu or Debian can be configured. By default, the Ubuntu distribution is installed on all virtual machines. To use Debian instead, set os.distro property to Debian.

cluster:
  nodeTemplate:
    os:
      distro: debian # (1)!
  1. By default, ubuntu is used.

Available OS distribution presets are the following:

  • ubuntu - Latest Ubuntu 22.04 release. (default)
  • ubuntu22 - Ubuntu 22.04 release 2022-07-12.
  • ubuntu20 - Ubuntu 20.04 release 2022-07-11.
  • debian - Latest Debian 11 release.
  • debian11 - Debian 11 release 2022-07-11.

Ubuntu images are downloaded from the Ubuntu cloud image repository and Debian images are downloaded from the Debian cloud image repository.

Custom OS source🔗︎

v2.1.0

If the presets do not meet your needs, you can also use a custom Ubuntu or Debian image by simply specifying the image source. The source of an image can be either a local path on a system or an URL pointing to the image download.

cluster:
  nodeTemplate:
    os:
      distro: ubuntu
      source: https://cloud-images.ubuntu.com/focal/current/focal-server-cloudimg-amd64.img

Primary OS network interface🔗︎

v2.1.0

When a virtual machine is created, the network interface names are evaluated deterministically. Therefore, Kubitect should use the correct network interface names for all available presets.

However, if you want to instruct Kubitect to use a specific network interface as primary, set its name as the value of the os.networkInterface property.

cluster:
  nodeTemplate:
    os:
      networkInterface: ens3

Custom DNS list🔗︎

v2.1.0

The list of Domain Name Servers (DNS) can be configured in the node template. These servers are used by all virtual machines for DNS resolution. By default, a DNS list contains only the network gateway.

cluster:
  nodeTemplate:
    dns: # (1)!
      - 1.1.1.1
      - 1.0.0.1
  1. IP addresses 1.1.1.1 and 1.0.0.1 represent CloudFlare's primary and secondary public DNS resolvers, respectively.

CPU mode🔗︎

v2.2.0   Default: custom

The CPU mode property can be used to simplify the configuration of a guest CPU to be as close as possible to the host CPU. Consult the libvirt documentation to learn about all available CPU modes:

  • custom (default)
  • host-model
  • host-passthrough
  • maximum
cluster:
  nodeTemplate:
    cpuMode: host-passthrough

SSH options🔗︎

Custom SSH certificate🔗︎

v2.0.0

Kubitect ensures that SSH certificates are automatically generated before the cluster is deployed. The generated certificates are located in the config/.ssh/ directory inside a cluster directory. You can use a custom SSH certificate by specifying a local path to the private key. Note that the public key must be located in the same directory with the .pub suffix.

cluster:
  nodeTemplate:
    ssh:
      privateKeyPath: "~/.ssh/id_rsa_test"

Warning

SSH certificates must be passwordless, otherwise Kubespray will fail to configure the cluster.

Adding nodes to the known hosts🔗︎

v2.0.0   Default: false

In addition, Kubitect allows you to add all created virtual machines to SSH known hosts on the local machine. To enable this behavior, set the addToKnownHosts property to true.

cluster:
  nodeTemplate:
    ssh:
      addToKnownHosts: true