How to Setup Kubernetes Cluster in Google Cloud Virtual Machine using "kubeadm"? | Ubuntu 20.04/22.04 LTS

 

Hello Friends,

In this post, we are going to setup Kubernetes Cluster on Virtual Machine in Google Cloud Platform using kubeadm tool. Hope this post will help you in Kubernetes learning Hand-On Labs (HOL).

Requirements:

Master Node: No. of VMs 1

Specifications - 2 vCPUs, 4GB RAM, 20 GB HDD (Balanced PD or SSD PD), Operating System (OS) Ubuntu 20.04 LTS x86/64, amd64 

Firewall Rule - Ingress Allow 6443 (API Server) | 2379 (ETCD) | 10251 (Scheduler) | 10252 (Controller Manager) 10250 (Kubelet), sudo access with admin access 

Worker Node: No. of VMs 2

Specifications - 2 vCPUs, 4GB RAM, 20 GB HDD (Balanced PD or SSD PD), Operating System (OS) Ubuntu 20.04 LTS x86/64, amd64 

Firewall Rule - Ingress Allow 30000-32767 (Services) | 10250 (Kubelet), sudo access with admin access 

Disable Swap and comment fstab entry:

First, Disable Swap and remove or comment the Swap entries from fstab file :

sudo swapoff -a

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

Next, Load the below kernel module on all the nodes (master and workers) | Bridge Traffic.

sudo tee /etc/modules-load.d/containerd.conf <<EOF
overlay
br_netfilter
EOF

sudo modprobe overlay

sudo modprobe br_netfilter

lsmod | grep br_netfilter

Now, we have to set the following Kernel parameters

sudo tee /etc/sysctl.d/kubernetes.conf <<EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1
EOF

Apply the changes, reload system configuration

sudo systemctl --system

Install Docker/Containerd runtime: (Run on both Master and worker node)

sudo apt install -y curl gnupg2 software-properties-common apt-transport-https ca-certificates

Enable docker repository and Install Docker and Containerd Runtime

sudo curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmour -o /etc/apt/trusted.gpg.d/docker.gpg

sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"

sudo apt update

sudo apt install -y containerd.io docker.io

Configure containerd so that it starts using systemd as cgroup.

containerd config default | sudo tee /etc/containerd/config.toml >/dev/null 2>&1

sudo sed -i 's/SystemdCgroup \= false/SystemdCgroup \= true/g' /etc/containerd/config.toml

Restart and enable containerd service

sudo systemctl restart containerd

sudo systemctl enable containerd

sudo systemctl restart docker

sudo systemctl enable docker

Installation of "kubeadm" "kubelet" and "kubectl"

Adding APT repository for Kubernetes

sudo systemctl enable docker

curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo gpg --dearmour -o /etc/apt/trusted.gpg.d/kubernetes-xenial.gpg

sudo apt-add-repository "deb http://apt.kubernetes.io/ kubernetes-xenial main"

Installing kubeadm, kubelet and kubectl

sudo apt update

sudo apt install -y kubelet kubeadm kubectl

Pause/Hold the auto update for the all 3 above installed packages

sudo apt-mark hold -y kubelet kubeadm kubectl

Now, finally start and enable the kubelet

sudo systemctl daemon-reload

sudo systemctl enable kubelet

sudo systemctl restart kubelet

sudo systemctl status kubelet

Initializing Kubernetes Control Plane with "kubeadm" | Run on Master Node only

sudo kubeadm init

Once, Your Kubernetes Control Plan initialized successfully. It will prompt you few commands for start using your cluster.

mkdir -p $HOME/.kube

sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config

sudo chown $(id -u):$(id -g) $HOME/.kube/config

Now, run the following kubectl commands to view cluster and node status.

kubectl cluster-info

kubectl get nodes

Join Worker Node to the Kubernetes Master Node/Control Plane

Run this command in each worker node to join master. Run the command given below after initialized successfully messege. (Similar to below) | Only Worker Nodes

kubeadm join 10.128.0.255:6443 --token ug227.1t6vnwhra8cr95m \
        --discovery-token-ca-cert-hash sha256:f5d5fffad20df7d81799f98162c0a7c6c54d07ec17cefffd84578371118d116b

Now, run the Following command on master node/control plane to see if the worker node joined.

kubectl get nodes -o wide

Setup Pod Network (Weave Network)

Now, the final steps is to deploy a pod network to the cluster. Documentation link given same screen after Control Plane initialized successfully screen. Open that link and setup pod network as your choice.

Here we are going to setup Weave Net kube-addon:

kubectl apply -f https://github.com/weaveworks/weave/releases/download/v2.8.1/weave-daemonset-k8s.yaml

Check the status of all the kube-system namespace pods, if everything is in "Running" state:

kubectl get pods -n kube-system

kubectl get nodes -o wide

Thanks a lot for your time reading this blog post. Stay tune for new exciting contents.