kubeadm-cluster-provisioning

Provision kubernetes cluster using kubeadm in local virtual machine(Without cloud provider)

Run virtual machine locally and ssh into it.

• Install oracle virtual box and run ubuntu server 22.04 LTS. Installation guide.

• Recommended vm system requirements:

  • CPU >= 2 cores
  • Memory >= 2 GB
  • Storage >= 20GB

Provision k8s cluster (Single node)

Permanently disable swap. Updates on swap:

• kubernetes/kubernetes#53533
• https://github.com/kubernetes/enhancements/tree/master/keps/sig-node/2400-node-swap

swapoff -a; sed -i '/swap/d' /etc/fstab

• Install container runtime (containerd)

  • Install [containerd] (https://github.com/containerd/containerd/blob/main/docs/getting-started.md)
  • Install runc
  • Install cni-plugins
  • Generate config.toml file for containerd. [Guide]
  • Configure systemd cgroup driver. [Guide]

• Install kubeadm, kubelet, kubectl. [Guide]

• Bootstarp cluster. [Guide]

 kubeadm init --pod-network-cidr=192.168.0.0/16 --ignore-preflight-errors=all

• Install Calico for Pod network add on.

• Untainted Node to run pods in Control plane. [Ref]

kubectl taint nodes --all node-role.kubernetes.io/control-plane- node-role.kubernetes.io/master-

• Use cluster

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

Alternatively, if you are the root user, you can run:

export KUBECONFIG=/etc/kubernetes/admin.conf

• Check the pods.

kubectl get pods -A

Acknowledgement

A big thanks to Emruz Hossain bhai for the k8s provision workflow contents.

Resources

• Kubernetes Networking

  • https://www.cloudflare.com/learning/network-layer/what-is-an-autonomous-system/
  • https://www.cloudflare.com/learning/security/glossary/what-is-bgp/
  • https://www.magalix.com/blog/kubernetes-cluster-networking-101

• Container Network Interface

  • https://kubernetes.io/docs/concepts/cluster-administration/networking/#how-to-implement-the-kubernetes-networking-model
  • https://kubernetes.io/docs/concepts/architecture/cri/
  • Introduction to CNI, the Container Network Interface Project - Bryan Boreham & Dan Williams
  • Below Kubernetes: Demystifying container runtimes
  • Kubernetes Networking: How to Write a CNI Plugin From Scratch - Eran Yanay, Twistlock