setup-debian-for-kubernetes

Description

This script help you to quickly setup a kubernetes cluster on Debian12 or Ubuntu22.

• PHASE1: Install Kubernetes and prerequisites
• PHASE2: Initialize a cluster
• PHASE3: Join other node

PHASE1: Install Kubernetes and prerequisites

Setup the operating system with prerequisites to run kubernetes.

The script follow kubernetes prerequisites :

• https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/install-kubeadm/
• https://kubernetes.io/docs/setup/production-environment/container-runtimes/

The script let you the choose the kubernetes version or default to the latest version.

The CRI (Container Runtime Interface) is Containerd.

PHASE2: Initialize a cluster

You can initialize a cluster with a CNI (Container Network Interface). You can do that with the option '--init' or '--prod'.

Supported CNI:

• calico (default)
• antrea

In progess of supporting CNI:

• cilium (Soon...) I've issue with pod newtorking but you can try yourself with '--force'

For production cluster, a minimum of 3 controllers is advised. You need to prepare the API_ENDPOINT of your production cluster. You have in 3 way:

• With a FQDN. This fqdn name must be in your DNS Server
• With a VIRTUAL_IP. If you have a loadbalancer for your controle plane.
• With a FQDN and with a FQDN.

PHASE3: Join other node

If you want to add to your cluster you need to:

1. Install Kubernetes and prerequisites. So Run the script without args '--init' and '--prod'
2. Launch the 'kubeadm join' command you are going to see at the end of the initalization of the cluster (PHASE2)

Installed packages

The script install those packages:

• kubernetes (repo: https://apt.kubernetes.io/ )
• containerd (repo: of the distrib)
• heml (repo: of the distrib)
• openvswitch-switch (repo: of the distrib) (when cni is antrea)

Launch on the first controller node

As root

root@control-01:~# bash install_kubernetes.sh

Or as an un-privileged user

user@control-01:~$ sudo bash install_kubernetes.sh

Chose your version of Kubernetes

The script ask you witch version of kubertenetes packages you want. By defaut it install the lastet version available.

1) Kubernetes-1.24
2) Kubernetes-1.25
3) Kubernetes-1.26
4) Kubernetes-1.27
5) Kubernetes-1.28 (latest)
Install (5):

At the end of PHASE1 (Install Kubernetes and prerequisites), you will see that

INFO: Installed Kubertenes packages
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name           Version      Architecture Description
+++-==============-============-============-=====================================
hi  kubeadm        1.28.2-00    amd64        Kubernetes Cluster Bootstrapping Tool
hi  kubectl        1.28.2-00    amd64        Kubernetes Command Line Tool
hi  kubelet        1.28.2-00    amd64        Kubernetes Node Agent

INFO: You are ready to go with : kubeadm init

At the end of PHASE2 (Initialize a cluster), you will see that

WARNING: To start using your cluster as  <root>          You to need to re-connect or run:  export KUBECONFIG=/etc/kubernetes/admin.conf

   To start using your cluster, please scroll-up (Ctrl+Shit Arrow-up) to see what to do.

   Notice: For root user we have already added the export in /root/.profile

   To join other nodes in the cluster you must install the same version of kubernetes.
   To do that you can run this on them :
      1. bash install_kubernetes.sh --cni calico 1.28
      2. kubeadm --join  <args>
      Please scroll-up (Ctrl+Shit Arrow-up) to see args to use.

   Have good time with Kubernetes.

Here you can see in that sample, that I 've chosen to install kubernetes with calico (default CNI).

Exemple to setup my worker node as root

root@control-01:~# scp install_kubernetes.sh root@worker-01:
root@control-01:~# ssh root@worker-01

root@worker-01:~# bash install_kubernetes.sh --cni calico 1.28
root@worker-01:~# kubeadm join 192.168.10.11:6443 --token sc1zw7.0exkak1fborbrbjt \
        --discovery-token-ca-cert-hash sha256:a870fa93c0c4ded0b892879d397c0374484defc41305e5122308bd01dea174a7