Create a Kubernetes Cluster using Ansible and vanilla upstream Kubernetes distro k0s
This playbook is largely based on the extensive and outstanding work of the contributors of k3s-ansible and, of course, kubespray.
site.yml:
$ ansible-playbook site.yml -i inventory/multipass/inventory.ymlYour inventory must include at least one initial_controller and one worker node. To get a highly available control plane more controller nodes can be added. The first initial controller creates tokens that get written to the nodes when the playbook is executed.
reset.yml:
$ ansible-playbook reset.yml -i inventory/multipass/inventory.ymlDeletes k0s all its files, directories and services from all hosts.
You can find a user guide on how to use this playbook in the k0s documentation.
For the quick creation of virtual machines, I have added a script that provisions a bunch of nodes via multipass and another small Python script that generates an Ansible inventory from the created instances.
Steps:
Create 5 instances with multipass and import your ssh public key with cloud-init (create_instances.sh):
$ ./tools/multipass_create_instances.sh
Create cloud-init to import ssh key...
[1/5] Creating instance k0s-1 with multipass...
Launched: k0s-1
...
Name State IPv4 Image
k0s-1 Running 192.168.64.32 Ubuntu 20.04 LTS
k0s-2 Running 192.168.64.33 Ubuntu 20.04 LTS
k0s-3 Running 192.168.64.56 Ubuntu 20.04 LTS
k0s-4 Running 192.168.64.57 Ubuntu 20.04 LTS
k0s-5 Running 192.168.64.58 Ubuntu 20.04 LTSGenerate your Ansible inventory:
$ cp -rfp inventory/sample inventory/multipass
$ ./tools/multipass_generate_inventory.py
Designate first instance as control plane
Created Ansible Inventory at: /Users/dev/k0s-ansible/tools/inventory.yml
$ cp tools/inventory.yml inventory/multipass/inventory.ymlTest the ssh connection to all instances in your inventory.yml:
$ ansible -i inventory/multipass/inventory.yml -m ping all
k0s-4 | SUCCESS => {
"ansible_facts": {
"discovered_interpreter_python": "/usr/bin/python3"
},
"changed": false,
"ping": "pong"
}
k0s-1 | SUCCESS => {
...Create your cluster:
$ ansible-playbook site.yml -i inventory/multipass/inventory.yml
...
TASK [k0s/initial_controller : print kubeconfig command] *******************************************************
Friday 22 January 2021 15:32:44 +0100 (0:00:00.247) 0:04:25.177 ********
ok: [k0s-1] => {
"msg": "To use Cluster: export KUBECONFIG=/Users/dev/k0s-ansible/inventory/multipass/artifacts/k0s-kubeconfig.yml"
}
...
PLAY RECAP *****************************************************************************************************
...
Friday 22 January 2021 15:32:58 +0100 (0:00:00.575) 0:04:39.234 ********
===============================================================================
download : Download k0s binary k0s-v0.10.0-beta1-amd64 ------------------------------------------------ 225.86s
prereq : Install apt packages -------------------------------------------------------------------------- 17.30s
k0s/initial_controller : Wait for k8s apiserver -------------------------------------------------------- 15.34s
k0s/controller : Wait for k8s apiserver ----------------------------------------------------------------- 3.36s
Gathering Facts ----------------------------------------------------------------------------------------- 1.35s
prereq : Create k0s Directories ------------------------------------------------------------------------- 0.86s
Gathering Facts ----------------------------------------------------------------------------------------- 0.84s
k0s/worker : Create k0s worker service with install command --------------------------------------------- 0.80s
Gathering Facts ----------------------------------------------------------------------------------------- 0.79s
k0s/initial_controller : Create k0s initial controller service with install command ------------------------- 0.76s
k0s/initial_controller : Enable and check k0s service --------------------------------------------------- 0.74s
k0s/controller : Create k0s controller service with install command ----------------------------------------- 0.72s
prereq : Write the k0s config file ---------------------------------------------------------------------- 0.69s
Gathering Facts ----------------------------------------------------------------------------------------- 0.68s
Gathering Facts ----------------------------------------------------------------------------------------- 0.65s
k0s/worker : Enable and check k0s service --------------------------------------------------------------- 0.58s
k0s/controller : Enable and check k0s service ----------------------------------------------------------- 0.53s
k0s/worker : Write the k0s token file on worker --------------------------------------------------------- 0.48s
k0s/controller : Write the k0s token file on controller ------------------------------------------------- 0.44s
k0s/initial_controller : Set controller IP in kubeconfig ------------------------------------------------ 0.32sConnect to your new Kubernetes cluster. The config is ready to use in the inventory/artifacts directory:
$ export KUBECONFIG=/Users/dev/k0s-ansible/inventory/multipass/artifacts/k0s-kubeconfig.yml
$ kubectl get nodes -o wide
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
k0s-4 Ready <none> 17m v1.20.2-k0s1 192.168.64.57 <none> Ubuntu 20.04.1 LTS 5.4.0-62-generic containerd://1.4.3
k0s-5 Ready <none> 17m v1.20.2-k0s1 192.168.64.58 <none> Ubuntu 20.04.1 LTS 5.4.0-62-generic containerd://1.4.3
$ kubectl run hello-k0s --image=quay.io/prometheus/busybox --rm -it --restart=Never --command -- sh -c "echo hello k0s"
hello k0s
pod "hello-k0s" deleted$ multipass delete $(multipass list --format csv | grep 'k0s' | cut -d',' -f1)
$ multipass purgeIt's assumed that vagrant is installed, if not, download and install it from their website
After that consult the readme
I welcome issues to and pull requests against this repository!