Digital Rebar

Prerequisites

• 3 nodes (please see hardware requirements)
• Loadbalancer
• Digital Rebar Server
• Talosctl access (see talosctl setup)

Creating a Cluster

In this guide we will create an Kubernetes cluster with 1 worker node, and 2 controlplane nodes. We assume an existing digital rebar deployment, and some familiarity with iPXE.

We leave it up to the user to decide if they would like to use static networking, or DHCP. The setup and configuration of DHCP will not be covered.

Create the Machine Configuration Files

Generating Base Configurations

Using the DNS name of the load balancer, generate the base configuration files for the Talos machines:

$ talosctl gen config talos-k8s-metal-tutorial https://<load balancer IP or DNS>:<port>
created controlplane.yaml
created worker.yaml
created talosconfig

The loadbalancer is used to distribute the load across multiple controlplane nodes. This isn’t covered in detail, because we asume some loadbalancing knowledge before hand. If you think this should be added to the docs, please create a issue.

At this point, you can modify the generated configs to your liking. Optionally, you can specify --config-patch with RFC6902 jsonpatch which will be applied during the config generation.

Validate the Configuration Files

$ talosctl validate --config controlplane.yaml --mode metal
controlplane.yaml is valid for metal mode
$ talosctl validate --config worker.yaml --mode metal
worker.yaml is valid for metal mode

Publishing the Machine Configuration Files

Digital Rebar has a build-in fileserver, which means we can use this feature to expose the talos configuration files. We will place controlplane.yaml, and worker.yaml into Digital Rebar file server by using the drpcli tools.

Copy the generated files from the step above into your Digital Rebar installation.

drpcli file upload <file>.yaml as <file>.yaml

Replacing <file> with controlplane or worker.

Download the boot files

Download a recent version of boot.tar.gz from github.

Upload to DRB:

$ drpcli isos upload boot.tar.gz as talos.tar.gz
{
  "Path": "talos.tar.gz",
  "Size": 96470072
}

We have some Digital Rebar example files in the Git repo you can use to provision Digital Rebar with drpcli.

To apply these configs you need to create them, and then apply them as follow:

$ drpcli bootenvs create talos
{
  "Available": true,
  "BootParams": "",
  "Bundle": "",
  "Description": "",
  "Documentation": "",
  "Endpoint": "",
  "Errors": [],
  "Initrds": [],
  "Kernel": "",
  "Meta": {},
  "Name": "talos",
  "OS": {
    "Codename": "",
    "Family": "",
    "IsoFile": "",
    "IsoSha256": "",
    "IsoUrl": "",
    "Name": "",
    "SupportedArchitectures": {},
    "Version": ""
  },
  "OnlyUnknown": false,
  "OptionalParams": [],
  "ReadOnly": false,
  "RequiredParams": [],
  "Templates": [],
  "Validated": true
}

drpcli bootenvs update talos - < bootenv.yaml

You need to do this for all files in the example directory. If you don’t have access to the drpcli tools you can also use the webinterface.

It’s important to have a corresponding SHA256 hash matching the boot.tar.gz

Bootenv BootParams

We’re using some of Digital Rebar build in templating to make sure the machine gets the correct role assigned.

talos.platform=metal talos.config={{ .ProvisionerURL }}/files/{{.Param \"talos/role\"}}.yaml"

This is why we also include a params.yaml in the example directory to make sure the role is set to one of the following:

• controlplane
• worker

The {{.Param \"talos/role\"}} then gets populated with one of the above roles.

Boot the Machines

In the UI of Digital Rebar you need to select the machines you want te provision. Once selected, you need to assign to following:

• Profile
• Workflow

This will provision the Stage and Bootenv with the talos values. Once this is done, you can boot the machine.

To understand the boot process, we have a higher level overview located at metal overview.

Bootstrap Etcd

To configure talosctl we will need the first control plane node’s IP:

Set the endpoints and nodes:

talosctl --talosconfig talosconfig config endpoint <control plane 1 IP>
talosctl --talosconfig talosconfig config node <control plane 1 IP>

Bootstrap etcd:

talosctl --talosconfig talosconfig bootstrap

Retrieve the kubeconfig

At this point we can retrieve the admin kubeconfig by running:

talosctl --talosconfig talosconfig kubeconfig .