Vultr

Creating a Cluster using the Vultr CLI

This guide will demonstrate how to create a highly-available Kubernetes cluster with one worker using the Vultr cloud provider.

Vultr have a very well documented REST API, and an open-source CLI tool to interact with the API which will be used in this guide. Make sure to follow installation and authentication instructions for the vultr-cli tool.

Boot Options

Upload an ISO Image

First step is to make the Talos ISO available to Vultr by uploading the latest release of the ISO to the Vultr ISO server.

vultr-cli iso create --url https://github.com/siderolabs/talos/releases/download/v1.7.6/metal-amd64.iso

Make a note of the ID in the output, it will be needed later when creating the instances.

PXE Booting via Image Factory

Talos Linux can be PXE-booted on Vultr using Image Factory, using the vultr platform: e.g. https://pxe.factory.talos.dev/pxe/376567988ad370138ad8b2698212367b8edcb69b5fd68c80be1f2ec7d603b4ba/v1.7.6/vultr-amd64 (this URL references the default schematic and amd64 architecture).

Create a Load Balancer

A load balancer is needed to serve as the Kubernetes endpoint for the cluster.

vultr-cli load-balancer create \
   --region $REGION \
   --label "Talos Kubernetes Endpoint" \
   --port 6443 \
   --protocol tcp \
   --check-interval 10 \
   --response-timeout 5 \
   --healthy-threshold 5 \
   --unhealthy-threshold 3 \
   --forwarding-rules frontend_protocol:tcp,frontend_port:443,backend_protocol:tcp,backend_port:6443

Make a note of the ID of the load balancer from the output of the above command, it will be needed after the control plane instances are created.

vultr-cli load-balancer get $LOAD_BALANCER_ID | grep ^IP

Make a note of the IP address, it will be needed later when generating the configuration.

Create the Machine Configuration

Generate Base Configuration

Using the IP address (or DNS name if one was created) of the load balancer created above, generate the machine configuration files for the new cluster.

talosctl gen config talos-kubernetes-vultr https://$LOAD_BALANCER_ADDRESS

Once generated, the machine configuration can be modified as necessary for the new cluster, for instance updating disk installation, or adding SANs for the certificates.

Validate the Configuration Files

talosctl validate --config controlplane.yaml --mode cloud
talosctl validate --config worker.yaml --mode cloud

Create the Nodes

Create the Control Plane Nodes

First a control plane needs to be created, with the example below creating 3 instances in a loop. The instance type (noted by the --plan vc2-2c-4gb argument) in the example is for a minimum-spec control plane node, and should be updated to suit the cluster being created.

for id in $(seq 3); do
    vultr-cli instance create \
        --plan vc2-2c-4gb \
        --region $REGION \
        --iso $TALOS_ISO_ID \
        --host talos-k8s-cp${id} \
        --label "Talos Kubernetes Control Plane" \
        --tags talos,kubernetes,control-plane
done

Make a note of the instance IDs, as they are needed to attach to the load balancer created earlier.

vultr-cli load-balancer update $LOAD_BALANCER_ID --instances $CONTROL_PLANE_1_ID,$CONTROL_PLANE_2_ID,$CONTROL_PLANE_3_ID

Once the nodes are booted and waiting in maintenance mode, the machine configuration can be applied to each one in turn.

talosctl --talosconfig talosconfig apply-config --insecure --nodes $CONTROL_PLANE_1_ADDRESS --file controlplane.yaml
talosctl --talosconfig talosconfig apply-config --insecure --nodes $CONTROL_PLANE_2_ADDRESS --file controlplane.yaml
talosctl --talosconfig talosconfig apply-config --insecure --nodes $CONTROL_PLANE_3_ADDRESS --file controlplane.yaml

Create the Worker Nodes

Now worker nodes can be created and configured in a similar way to the control plane nodes, the difference being mainly in the machine configuration file. Note that like with the control plane nodes, the instance type (here set by --plan vc2-1-1gb) should be changed for the actual cluster requirements.

for id in $(seq 1); do
    vultr-cli instance create \
        --plan vc2-1c-1gb \
        --region $REGION \
        --iso $TALOS_ISO_ID \
        --host talos-k8s-worker${id} \
        --label "Talos Kubernetes Worker" \
        --tags talos,kubernetes,worker
done

Once the worker is booted and in maintenance mode, the machine configuration can be applied in the following manner.

talosctl --talosconfig talosconfig apply-config --insecure --nodes $WORKER_1_ADDRESS --file worker.yaml

Bootstrap etcd

Once all the cluster nodes are correctly configured, the cluster can be bootstrapped to become functional. It is important that the talosctl bootstrap command be executed only once and against only a single control plane node.

talosctl --talosconfig talosconfig boostrap --endpoints $CONTROL_PLANE_1_ADDRESS --nodes $CONTROL_PLANE_1_ADDRESS

Configure Endpoints and Nodes

While the cluster goes through the bootstrapping process and beings to self-manage, the talosconfig can be updated with the endpoints and nodes.

talosctl --talosconfig talosconfig config endpoints $CONTROL_PLANE_1_ADDRESS $CONTROL_PLANE_2_ADDRESS $CONTROL_PLANE_3_ADDRESS
talosctl --talosconfig talosconfig config nodes $CONTROL_PLANE_1_ADDRESS $CONTROL_PLANE_2_ADDRESS $CONTROL_PLANE_3_ADDRESS WORKER_1_ADDRESS

Retrieve the kubeconfig

Finally, with the cluster fully running, the administrative kubeconfig can be retrieved from the Talos API to be saved locally.

talosctl --talosconfig talosconfig kubeconfig .

Now the kubeconfig can be used by any of the usual Kubernetes tools to interact with the Talos-based Kubernetes cluster as normal.