zamabraga / k3s

Create a k3s cluster

K3s

Project to configurate k3s cluster using terraform and ansible

Project structure

• azure/ - Terraform scripts to create k3s cluster in Azure
• k3s/ - Terraform scritps to manager k3s clustes
• scripts/ - Ansible scripts to install and configurate k3s

Minimum Requirements

• RAM: 1G
• CPU: 1 Minimum

Networking

Protocol	Port	Source	Description
TCP	6443	K3s agent nodes	Kubernetes API Server
UDP	8472	K3s server and agent nodes	Required only for Flannel VXLAN
UDP	51820	K3s server and agent nodes	Required only for Flannel Wireguard backend
UDP	51821	K3s server and agent nodes	Required only for Flannel Wireguard backend with IPv6
TCP	10250	K3s server and agent nodes	Kubelet metrics
TCP	2379-2380	K3s server nodes	Required only for HA with embedded etcd

Architecture

Single Server

Quick-Start Guide

K3S Single Server

Create Infrastructure

cd ./azure
terraform apply --auto-approve
module.vm["corvo"].azurerm_linux_virtual_machine.main: Still creating... [30s elapsed]
module.vm["corvo"].azurerm_linux_virtual_machine.main: Still creating... [40s elapsed]
module.vm["corvo"].azurerm_linux_virtual_machine.main: Still creating... [50s elapsed]
module.vm["corvo"].azurerm_linux_virtual_machine.main: Creation complete after 54s [id=/subscriptions/f966f250-34fe-4c57-83b9-4ee6f265a741/resourceGroups/rg-k3s-test/providers/Microsoft.Compute/virtualMachines/corvo]

Apply complete! Resources: 1 added, 4 changed, 0 destroyed.

Outputs:

details = {
  "corvo" = {
    "fqdn" = "corvo.eastus.cloudapp.azure.com" #DNS
    "ip_address" = "" #Public IP
  }
}

Server configuration

ssh-keyscan -H [Host IP]  >> ~/.ssh/known_hosts  #Add host's fingerprint 
export K3S_USER=[USER] # Set user login
export K3S_PASSWORD=[PASSWORD USER] # Set user password

ansible-playbook -i hosts.yaml playbooks/install-k3s-single-server.yaml

K3s Configuration

cd ./k3s
terraform apply --auto-approve

Tests

curl http://127.0.0.1/whoami
curl http://[PUBLIC ID]/whoami
curl http://corvo.eastus.cloudapp.azure.com/whoami

Tips

Export base-64 from notepad++ to github secrets

Docs

https://docs.k3s.io/

https://docs.k3s.io/installation/requirements

https://thenewstack.io/how-rancher-labs-k3s-makes-it-easy-to-run-kubernetes-at-the-edge/

https://mattermost.com/blog/intro-to-k3s-lightweight-kubernetes/

https://github.com/actions-hub/kubectl

https://www.ivankrizsan.se/2020/10/31/hot-ingress-in-the-k3s-cluster/

https://www.rancher.co.jp/docs/k3s/latest/en/running/

https://www.suse.com/c/rancher_blog/introduction-to-k3s/

Postgresql

https://www.techtalk7.com/postgresql-storage-on-k3s/

https://wirywolf.com/2022/07/postgresql-ingress-using-traefik-kubernetes-k3s.html

https://community.traefik.io/t/ingressroutetcp-not-possible-anymore/8472

https://community.traefik.io/t/ingressroutetcp-in-kubernetes-for-headless-service/13726/2

https://community.traefik.io/t/tcp-on-kubernetes/1528/21

https://www.kisphp.com/postgres/run-postgres11-and-pgadmin4-in-kubernetes-for-testing