How to Deploy a Kubernetes Cluster in Azure Virtual Machines?

Azure Kubernetes Service provides a platform for managing containers with the help of Kubernetes. It also provides an easy and managed way for the deployment and scaling of containerized applications. Containerized applications are deployed in the Kubernetes cluster in Azure. But we can also manually set up a Kubernetes cluster in Azure. Let’s see how to deploy a Kubernetes cluster on Azure VMs.

• Kubernetes: It is an open-source container orchestration platform designed to automate the deployment, scaling, and management of containerized applications.
• Kubernetes Cluster: It is a set of nodes on which containerized applications run.

Step 1: Deploy Azure VM

• Go to the Azure portal and create a minimum of 2 virtual machines, as described in this article. Create VMs with a minimum configuration of 2 vCPUs and 8 GB RAM.
• Recommend you use Ubuntu as OS.
• One VM will act as a master node for our cluster while others will act as worker nodes.
• Once all VMs are deployed start with the following steps.
• Follow Step 2 to Step 5 for all the VMs.

Step 2: Disable the firewall for VM

• SSH to the VM using the below command

ssh username@public-ip

• As we will be starting Kubernetes API server the firewall may interfare with our output. Hence disable the firewall using below command.

sudo ufw disable

• Then disable swapping for swapping devices using below commands.

swapoff -a

sudo sed -i '/swap/d' /etc/fstab

• Now we will add following parameters in kernel parameters. Run below command.

cat <<EOF | sudo tee /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-iptables  = 1
net.bridge.bridge-nf-call-ip6tables = 1
net.ipv4.ip_forward                 = 1
EOF

• Apply the new system configuration using below command.

sudo sysctl --system

Step 3: Install the certificate applications.

• Install the below applications with the help of below command.

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

Step 4: Install Docker

• Now lets install docker as root user . first switch to root user

sudo su

• Add docker to apt list

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | apt-key add -

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

• Update the apt

apt update

• Finally install docker

apt install docker.io

Step 5: Install Kubernetes

• Being as root add kubernetes to apt list

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

echo "deb https://apt.kubernetes.io/ kubernetes-xenial main" > /etc/apt/sources.list.d/kubernetes.list

• Update the apt

apt update

• Finally install kubelet , kubeadm & kubectl

apt-get install -y kubelet kubeadm kubectl

Step 6: Initialize cluster and kubeadm (Only for master node)

• First get the Ip address of your machine.

ip addr

• From output copy address for eth0 interface.
• Initiate Kubeadm and start the cluster. Replace your IP address in command .

kubeadm init --apiserver-advertise-address=<apiserver-advertise-address-ip> --pod-network-cidr=192.168.0.0/16  --ignore-preflight-errors=all  

• This will start the Kubernetes api server . Copy the kubeadm join command from output which required in next steps .Finally add config files

export KUBECONFIG=/etc/kubernetes/admin.conf

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

• Now we are done with the configuration of master node . We just have to install container networking in cluster. Logout from root and then run below command

kubectl apply -f "https://github.com/weaveworks/weave/releases/download/v2.8.1/weave-daemonset-k8s-1.11.yaml"

Step 7: Connect The worker node.

• On worker node after following step 2 to 5 paste the kubeadm command copied from master node.
• You should see that worker node is joined.

Step 8: Verify the cluster.

• On master node run Kubernetes commands to list all components.

kubectl get all -A

Thus we have seen how we can install a Kubernetes cluster manually on Azure Virtual machines . This allows to build kubernetes cluster from scratch allowing to manage each component of Kubernetes separately. This can be furthur modified for complex configurations.

How do I deploy a Kubernetes cluster in Azure using AKS?

You can deploy an AKS cluster using the Azure Portal, Azure CLI, or Azure PowerShell. The process typically involves specifying cluster details, such as resource group, node size, and the number of nodes.

How does AKS handle updates and maintenance?

AKS automates updates to the Kubernetes control plane, ensuring that your cluster is running the latest version. You have control over node pool updates and can configure maintenance windows for minimal disruption.

What is kubeadm?

kubeadm is a command-line utility in Kubernetes that facilitates the process of setting up a Kubernetes cluster. It is part of the Kubernetes project and is designed to simplify the deployment and initialization of Kubernetes master and worker nodes.

What is master and worker node in kubernetes?

The master node is the control plane of the Kubernetes cluster. It is responsible for managing the overall state of the cluster, making decisions about where to schedule applications, and maintaining communication with nodes in the cluster.

Worker nodes are the machines (physical or virtual) where the actual workloads, such as containers and pods, run. These nodes host the applications and services that make up the work of the cluster.

What is kubectl?

kubectl is a command-line tool used to interact with Kubernetes clusters. It is the primary and official command-line interface (CLI) for managing and deploying applications on Kubernetes. With kubectl, users can execute commands against Kubernetes clusters to create, inspect, update, and delete resources.