Vagrant & Libvirt
Pre-requisities
- Linux OS
- Vagrant installed
- vagrant-libvirt plugin installed
- talosctl installed
- kubectl installed
Overview
We will use Vagrant and its libvirt plugin to create a KVM-based cluster with 3 control plane nodes and 1 worker node.
For this, we will mount Talos ISO into the VMs using a virtual CD-ROM, and configure the VMs to attempt to boot from the disk first with the fallback to the CD-ROM.
We will also configure a virtual IP address on Talos to achieve high-availability on kube-apiserver.
Preparing the environment
First, we download the latest metal-amd64.iso ISO from GitHub releases into the /tmp directory.
wget --timestamping curl https://factory.talos.dev/image/376567988ad370138ad8b2698212367b8edcb69b5fd68c80be1f2ec7d603b4ba/v1.8.0/metal-amd64.iso -O /tmp/metal-amd64.iso
Create a Vagrantfile with the following contents:
Vagrant.configure("2") do |config|
config.vm.define "control-plane-node-1" do |vm|
vm.vm.provider :libvirt do |domain|
domain.cpus = 2
domain.memory = 2048
domain.serial :type => "file", :source => {:path => "/tmp/control-plane-node-1.log"}
domain.storage :file, :device => :cdrom, :path => "/tmp/metal-amd64.iso"
domain.storage :file, :size => '4G', :type => 'raw'
domain.boot 'hd'
domain.boot 'cdrom'
end
end
config.vm.define "control-plane-node-2" do |vm|
vm.vm.provider :libvirt do |domain|
domain.cpus = 2
domain.memory = 2048
domain.serial :type => "file", :source => {:path => "/tmp/control-plane-node-2.log"}
domain.storage :file, :device => :cdrom, :path => "/tmp/metal-amd64.iso"
domain.storage :file, :size => '4G', :type => 'raw'
domain.boot 'hd'
domain.boot 'cdrom'
end
end
config.vm.define "control-plane-node-3" do |vm|
vm.vm.provider :libvirt do |domain|
domain.cpus = 2
domain.memory = 2048
domain.serial :type => "file", :source => {:path => "/tmp/control-plane-node-3.log"}
domain.storage :file, :device => :cdrom, :path => "/tmp/metal-amd64.iso"
domain.storage :file, :size => '4G', :type => 'raw'
domain.boot 'hd'
domain.boot 'cdrom'
end
end
config.vm.define "worker-node-1" do |vm|
vm.vm.provider :libvirt do |domain|
domain.cpus = 1
domain.memory = 1024
domain.serial :type => "file", :source => {:path => "/tmp/worker-node-1.log"}
domain.storage :file, :device => :cdrom, :path => "/tmp/metal-amd64.iso"
domain.storage :file, :size => '4G', :type => 'raw'
domain.boot 'hd'
domain.boot 'cdrom'
end
end
end
Bring up the nodes
Check the status of vagrant VMs:
vagrant status
You should see the VMs in “not created” state:
Current machine states:
control-plane-node-1 not created (libvirt)
control-plane-node-2 not created (libvirt)
control-plane-node-3 not created (libvirt)
worker-node-1 not created (libvirt)
Bring up the vagrant environment:
vagrant up --provider=libvirt
Check the status again:
vagrant status
Now you should see the VMs in “running” state:
Current machine states:
control-plane-node-1 running (libvirt)
control-plane-node-2 running (libvirt)
control-plane-node-3 running (libvirt)
worker-node-1 running (libvirt)
Find out the IP addresses assigned by the libvirt DHCP by running:
virsh list | grep vagrant | awk '{print $2}' | xargs -t -L1 virsh domifaddr
Output will look like the following:
virsh domifaddr vagrant_control-plane-node-2
Name MAC address Protocol Address
-------------------------------------------------------------------------------
vnet0 52:54:00:f9:10:e5 ipv4 192.168.121.119/24
virsh domifaddr vagrant_control-plane-node-1
Name MAC address Protocol Address
-------------------------------------------------------------------------------
vnet1 52:54:00:0f:ae:59 ipv4 192.168.121.203/24
virsh domifaddr vagrant_worker-node-1
Name MAC address Protocol Address
-------------------------------------------------------------------------------
vnet2 52:54:00:6f:28:95 ipv4 192.168.121.69/24
virsh domifaddr vagrant_control-plane-node-3
Name MAC address Protocol Address
-------------------------------------------------------------------------------
vnet3 52:54:00:03:45:10 ipv4 192.168.121.125/24
Our control plane nodes have the IPs: 192.168.121.203, 192.168.121.119, 192.168.121.125 and the worker node has the IP 192.168.121.69.
Now you should be able to interact with Talos nodes that are in maintenance mode:
talosctl -n 192.168.121.203 disks --insecure
Sample output:
DEV MODEL SERIAL TYPE UUID WWID MODALIAS NAME SIZE BUS_PATH
/dev/vda - - HDD - - virtio:d00000002v00001AF4 - 8.6 GB /pci0000:00/0000:00:03.0/virtio0/
Installing Talos
Pick an endpoint IP in the vagrant-libvirt subnet but not used by any nodes, for example 192.168.121.100.
Generate a machine configuration:
talosctl gen config my-cluster https://192.168.121.100:6443 --install-disk /dev/vda
Edit controlplane.yaml to add the virtual IP you picked to a network interface under .machine.network.interfaces, for example:
machine:
network:
interfaces:
- interface: eth0
dhcp: true
vip:
ip: 192.168.121.100
Apply the configuration to the initial control plane node:
talosctl -n 192.168.121.203 apply-config --insecure --file controlplane.yaml
You can tail the logs of the node:
sudo tail -f /tmp/control-plane-node-1.log
Set up your shell to use the generated talosconfig and configure its endpoints (use the IPs of the control plane nodes):
export TALOSCONFIG=$(realpath ./talosconfig)
talosctl config endpoint 192.168.121.203 192.168.121.119 192.168.121.125
Bootstrap the Kubernetes cluster from the initial control plane node:
talosctl -n 192.168.121.203 bootstrap
Finally, apply the machine configurations to the remaining nodes:
talosctl -n 192.168.121.119 apply-config --insecure --file controlplane.yaml
talosctl -n 192.168.121.125 apply-config --insecure --file controlplane.yaml
talosctl -n 192.168.121.69 apply-config --insecure --file worker.yaml
After a while, you should see that all the members have joined:
talosctl -n 192.168.121.203 get members
The output will be like the following:
NODE NAMESPACE TYPE ID VERSION HOSTNAME MACHINE TYPE OS ADDRESSES
192.168.121.203 cluster Member talos-192-168-121-119 1 talos-192-168-121-119 controlplane Talos (v1.1.0) ["192.168.121.119"]
192.168.121.203 cluster Member talos-192-168-121-69 1 talos-192-168-121-69 worker Talos (v1.1.0) ["192.168.121.69"]
192.168.121.203 cluster Member talos-192-168-121-203 6 talos-192-168-121-203 controlplane Talos (v1.1.0) ["192.168.121.100","192.168.121.203"]
192.168.121.203 cluster Member talos-192-168-121-125 1 talos-192-168-121-125 controlplane Talos (v1.1.0) ["192.168.121.125"]
Interacting with Kubernetes cluster
Retrieve the kubeconfig from the cluster:
talosctl -n 192.168.121.203 kubeconfig ./kubeconfig
List the nodes in the cluster:
kubectl --kubeconfig ./kubeconfig get node -owide
You will see an output similar to:
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
talos-192-168-121-203 Ready control-plane,master 3m10s v1.24.2 192.168.121.203 <none> Talos (v1.1.0) 5.15.48-talos containerd://1.6.6
talos-192-168-121-69 Ready <none> 2m25s v1.24.2 192.168.121.69 <none> Talos (v1.1.0) 5.15.48-talos containerd://1.6.6
talos-192-168-121-119 Ready control-plane,master 8m46s v1.24.2 192.168.121.119 <none> Talos (v1.1.0) 5.15.48-talos containerd://1.6.6
talos-192-168-121-125 Ready control-plane,master 3m11s v1.24.2 192.168.121.125 <none> Talos (v1.1.0) 5.15.48-talos containerd://1.6.6
Congratulations, you have a highly-available Talos cluster running!
Cleanup
You can destroy the vagrant environment by running:
vagrant destroy -f
And remove the ISO image you downloaded:
sudo rm -f /tmp/metal-amd64.iso