k8s-containerd-kubeadm-callico

Building a Kubernetes 1.23 Cluster with Kubeadm
Since, Kubernetes has removed docker shimp API and moved to containerd
This will help you build the skills necessary to create your own Kubernetes clusters in the real world.

Solution
SSH into the server and follow the instruction

Install Packages
Log into the Control Plane Node (Note: The following steps must be performed on all three nodes.).

---------- Create configuration file for containerd -----------
cat <<EOF | sudo tee /etc/modules-load.d/containerd.conf
overlay
br_netfilter
EOF
-------------------------Load modules-------------------------

sudo modprobe overlay
sudo modprobe br_netfilter
---------------------Set system configurations for Kubernetes networking---------------------------------
cat <<EOF | sudo tee /etc/sysctl.d/99-kubernetes-cri.conf
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1
net.bridge.bridge-nf-call-ip6tables = 1
EOF

------------------- Apply new settings -------------------
sudo sysctl --system
Install containerd:
sudo apt-get update && sudo apt-get install -y containerd
------------- Create default configuration file for containerd -------------
sudo mkdir -p /etc/containerd

Generate default containerd configuration and save to the newly created default file:
sudo containerd config default | sudo tee /etc/containerd/config.toml

Restart containerd to ensure new configuration file usage:
sudo systemctl restart containerd

Verify that containerd is running.
sudo systemctl status containerd

Disable swap:
sudo swapoff -a

Disable swap on startup in /etc/fstab:
sudo sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab

Install dependency packages:
sudo apt-get update && sudo apt-get install -y apt-transport-https curl

Download and add GPG key:
curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -

Add Kubernetes to repository list:
cat <<EOF | sudo tee /etc/apt/sources.list.d/kubernetes.list
deb https://apt.kubernetes.io/ kubernetes-xenial main
EOF

Update package listings:
sudo apt-get update

Install Kubernetes packages (Note: If you get a dpkg lock message, just wait a minute or two before trying the command again):
sudo apt-get install -y kubelet=1.23.0-00 kubeadm=1.23.0-00 kubectl=1.23.0-00

Turn off automatic updates:
sudo apt-mark hold kubelet kubeadm kubectl

***** Log into both Worker Nodes to perform previous step *****

-------------- MASTER --------------
Initialize the Cluster
Initialize the Kubernetes cluster on the control plane node using kubeadm (Note: This is only performed on the Control Plane Node):
sudo kubeadm init --pod-network-cidr 192.168.0.0/16 --kubernetes-version 1.23.0

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

Test access to cluster:
kubectl get nodes

Install the Calico Network Add-On
On the Control Plane Node, install Calico Networking:
kubectl apply -f https://docs.projectcalico.org/manifests/calico.yaml

Check status of the control plane node:
kubectl get nodes

******** Join the Worker Nodes to the Cluster
In the Control Plane Node, create the token and copy the kubeadm join command (NOTE:The join command can also be found in the output from kubeadm init command):
kubeadm token create --print-join-command

In both Worker Nodes, paste the kubeadm join command to join the cluster. Use sudo to run it as root:
sudo kubeadm join ...

In the Control Plane Node, view cluster status (Note: You may have to wait a few moments to allow all nodes to become ready):
kubectl get nodes

Congratulations — you've completed this hands-on lab!

==============================================================
Calico Debugging
ip link  show type veth
ip link show type ipip
ip route get

packet debugging using tcpdump
sudo apt install -y tcpdump

Packet debugging using tshark
sudo apt install -y tshark