Kubernetes Installation Guide

# Create Static Ip on master and worker's nodes
1. sudo nano /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg
2. Enter in /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg
network: {config: disabled}
3. sudo nano /etc/netplan/01-netcfg.yaml
4. Enter in /etc/netplan/01-netcfg.yaml
network:
  version: 2
  renderer: networkd
  ethernets:
    ens33: # Your network interface name
      dhcp4: no
      addresses:
        - 192.168.121.221/24 # Static Ip that you want to set 
      gateway4: 192.168.121.1 # Your IP gateway
      nameservers:
          addresses: [8.8.8.8, 1.1.1.1] # List of nameservers

5. Off the swap
sudo swapoff -a

6. Comment the swap in /etc/fstab

# Installation on all the nodes
7. Follow the Installation steps below
sudo apt-get update && sudo apt-get install -y apt-transport-https curl
sudo curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add
sudo apt-add-repository 'deb http://apt.kubernetes.io/ kubernetes-xenial main'
sudo apt-get update && sudo apt-get install -y kubelet=1.20.0-00 kubeadm=1.20.0-00 kubectl=1.20.0-00 docker.io
or 
sudo apt-get update && sudo apt-get install -y kubelet=1.22.4-00 kubeadm=1.22.4-00 kubectl=1.22.4-00 docker.io

# Before you start the docker service, please add the json below to /etc/docker/daemon.json. Create the file if it doesn't exist
vi /etc/docker/daemon.json
{
  "exec-opts": ["native.cgroupdriver=systemd"],
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "100m"
  },
  "storage-driver": "overlay2"
}

This is to ensure that kubeadm runs with the same cgroups driver as docker

8. Start the docker service
sudo systemctl start docker && sudo systemctl enable docker

# Control Plane Installation
9. Start the control plane
sudo kubeadm init --apiserver-advertise-address 192.168.0.82 --pod-network-cidr=172.16.0.0/16
note: pod-network-cidr -> please follow your docker's cidr. For that please check your docker0
note: please set your apiserver-advertise-address to master node's ip address

10. Once this is done please do the step below
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

11. Save your token and kubeadm join command that shows at the end of the output in this format
kubeadm join 192.168.0.82:6443 --token vois8r.3wx957459ooxm2dq \
        --discovery-token-ca-cert-hash sha256:5f1896c485802502f8059fae06b2688ef6771ec53cc2e5bd1a6dc433eaccd4bc
note: The token is important for your worker's node to join master node

12. Install a pod network to the cluster using calico
curl https://projectcalico.docs.tigera.io/manifests/calico.yaml -O
kubectl apply -f calico.yaml

# Worker's node 
1. Make sure that you have
a. swap is Off
b. docker's cgroupdriver is systemd

2. Run the following command
kubeadm join 192.168.0.82:6443 --token vois8r.3wx957459ooxm2dq \
        --discovery-token-ca-cert-hash sha256:5f1896c485802502f8059fae06b2688ef6771ec53cc2e5bd1a6dc433eaccd4bc

3. If the worker's node join successfully, it will show:
This node has joined the cluster:
* Certificate signing request was sent to apiserver and a response was received.
* The Kubelet was informed of the new secure connection details.

4. Wait for a good 2 minutes, check the status of the nodes
kubectl get nodes

5. You will see the status Ready for all the nodes
NAME          STATUS   ROLES                  AGE     VERSION
k8s-2         Ready    <none>                 8m19s   v1.23.4
k8s-3         Ready    <none>                 32s     v1.23.4
k8s-cluster   Ready    control-plane,master   16m     v1.23.4

#Reference
a. https://github.com/justmeandopensource/kubernetes/blob/master/docs/install-cluster-ubuntu-20.md
b. https://www.digitalocean.com/community/tutorials/how-to-create-a-kubernetes-cluster-using-kubeadm-on-ubuntu-20-04
c. https://computingforgeeks.com/deploy-kubernetes-cluster-on-ubuntu-with-kubeadm/
d. https://linuxconfig.org/how-to-install-kubernetes-on-ubuntu-20-04-focal-fossa-linux
e. https://stackoverflow.com/questions/54728254/kubernetes-kubeadm-init-fails-due-to-dial-tcp-127-0-0-110248-connect-connecti
f. https://kubernetes.io/docs/tasks/administer-cluster/kubeadm/configure-cgroup-driver/
g. https://projectcalico.docs.tigera.io/getting-started/kubernetes/self-managed-onprem/onpremises
h. https://www.learnitguide.net/2021/12/install-kubernetes-cluster-on-ubuntu-20.html
i. https://linuxize.com/post/how-to-configure-static-ip-address-on-ubuntu-20-04/
j. https://kubernetes.io/docs/concepts/cluster-administration/addons/
k. https://www.devopsschool.com/blog/how-to-change-the-cgroup-driver-from-cgroupfs-systemd-in-docker/
l. https://www.digitalocean.com/community/tutorials/how-to-install-and-use-docker-on-ubuntu-20-04