How to setup Kubernetes Cluster in Ubuntu using Kubeadm | Install Kubernetes Cluster in Ubuntu | Setup Master Node and worker Node in Ubuntu EC2

Kubernetes  is an open source container platform that eliminates many of the manual processes involved in deploying and scaling containerized applications. We will learn how to setup Kubernetes Cluster in Ubuntu 18.0.4. You can setup Kubernetes Cluster in many ways. One of the ways is to use Kubeadm.

Kubeadm is a tool built to provide kubeadm init and kubeadm join as best-practice “fast paths” for creating Kubernetes clusters.

Watch the steps in YouTube video:

Prerequisites:

1. Ubuntu instance with 4 GB RAM - Master Node - (with ports open to all traffic)

2. Ubuntu instance with at least 2 GB RAM - Worker Node - (with ports open to all traffic)

Kubernetes Setup using Kubeadm

###Start - Execute the below commands in both Master/worker nodes##########

Login to both instances execute the below commands:
sudo apt-get update -y  && sudo apt-get install apt-transport-https -y

Change to root user

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

cat <<EOF >/etc/apt/sources.list.d/kubernetes.list
deb https://apt.kubernetes.io/ kubernetes-xenial main
EOF

sudo apt-get update

#Disable swap memory for better performance
swapoff -a
sudo sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab

Enable IP tables
#We need to enable IT tables for pod to pod communication.

modprobe br_netfilter
sysctl -p
sudo sysctl net.bridge.bridge-nf-call-iptables=1

Install Docker on both Master and Worker nodes
apt-get install docker.io -y

Add ubuntu user to Docker group

usermod -aG docker ubuntu
systemctl restart docker
systemctl enable docker.service

Type exit to come out of root user.
Install Kubernetes Modules
sudo apt-get install -y kubelet kubeadm kubectl kubernetes-cni

sudo systemctl daemon-reload
sudo systemctl start kubelet
sudo systemctl enable kubelet.service

sudo systemctl status docker

#End - Execute the above commands in both Master/worker nodes##########

Initialize Kubeadm on Master Node(only on Master Node)

#Execute the below command as root user to initialize Kubernetes Master node.
sudo su -
kubeadm init

Make sure you see the above message to confirm master node is up.

#Now type exit to exit from root user and execute below commands as normal user

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

Installing the Weave Net Add-On
kubectl apply -f "https://cloud.weave.works/k8s/net?k8s-version=$(kubectl version | base64 | tr -d '\n')"

It make take a few mins to execute the above command and show show the below message.

Now execute the below command to see the pods.

kubectl get pods  --all-namespaces

Now login to Worker Node

Join worker node to Master Node

The below command will join worker node to master node, execute this a normal user by putting sudo before:

sudo kubeadm join <master_node_ip>:6443 --token xrvked.s0n9771cd9x8a9oc \
    --discovery-token-ca-cert-hash sha256:288084720b5aad132787665cb73b9c530763cd1cba10e12574b4e97452137b4a

Go to Master and type the below command

kubectl get nodes

the above command should display both Master and worker nodes.

It means Kubernetes Cluster - both Master and worker nodes are setup successfully and up and running!!!

Deploy Nginx on a Kubernetes Cluster
Let us run some apps to make sure they are deployed to Kuberneter cluster. We will do this in master node. The below command will create deployment:

kubectl create deployment nginx --image=nginx

View Deployments
kubectl get deployments

Create as a service 

kubectl create service nodeport nginx --tcp=80:80

kubectl get svc

run the above command to see a summary of the service and the ports exposed.

Now go Master or worker node, enter public dns and access it with port exposed

You should see the welcome page!

How to upload Docker images to Azure Container Registry | Hosting Docker images in Azure Container Registry

Azure Container Registry is a managed, private docker registry service. You can create and maintain Azure container registries to store and manage your private Docker container images.

It is alternative to Docker Hub. Azure Container Registry allows you to build, store, and manage container images and artifacts in a private registry for all types of container deployments.

Let us see how to upload a docker images from your VM into ACR.

Watch the steps below in YouTube channel:

Pre-requisites:

Make sure you have docker installed on your VM.
 

Step 1 - Create Azure Container Registry (ACR)

Go to https://portal.azure.com/
Create a Resource, Give container registry as a name

Click on Create

  

Enter values as mentioned below:

Give registry name, resource group and choose Enable admin user and SKU as Basic 

 Click on Review and then create, now your container registry is been created.

Step 2 - Download sample Python App

Go to your machine where you have docker images stored. perform below command to download sample pythonapp which is already dockerized.

 

git clone https://bitbucket.org/ananthkannan/mydockerrepo/src/master/pythonApp/ 

cd  pythonApp/pythonApp

Step 3 - Create docker image

docker build . -t mypythonapp

type below command:

sudo docker images

this should show docker images you have created locally.

Now go to ACR, click on docker registry you created. Click on access keys under Settings.

Copy value under login server 

Login to Azure Container Registry through command line.

sudo docker login mydockerazureregistry.azurecr.io

Username: mydockerazureregistry

Enter password by copying value below password

Step 4 - Tag and Push your docker image to ACR

Now tag the docker image per as below:

sudo docker tag mypythonapp mydockerazureregistry.azurecr.io/mypythonapp

sudo docker push mydockerazureregistry.azurecr.io/mypythonapp

That's it..Docker image is pushed into ACR. 

You can see the Docker image uploaded under Services--> repositories

Install Docker Ubuntu | How to install Docker in Ubuntu 24.0.4 | Setup Docker on Ubuntu

Please find steps needed for installing Docker in Ubuntu 24.0.4 instance. You can install in Docker in many ways. But try only one option.

Docker installation steps using default repository from Ubuntu
Update local packages by executing below command:
sudo apt update

Install the below packages
sudo apt install gnupg2 pass -y

gnupg2 is tool for secure communication and data storage. It can be used to encrypt data and to create digital signatures
 

Install docker
sudo apt install docker.io -y

Add Ubuntu user to Docker group
sudo usermod -aG docker $USER

We need to reload shell in order to have new group settings applied. Now you need to logout and log back in command line or execute the below command:
newgrp docker

The Docker service needs to be setup to run at startup. To do so, type in each command followed by enter:

sudo systemctl start docker

sudo systemctl enable docker
sudo systemctl status docker

The above screenshot should confirm that Docker daemon is up and running.

Docker installation steps using Official Docker Repository (Alternative installation steps)

sudo curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"
sudo apt-get update
sudo apt-cache policy docker-ce
sudo apt-get install -y docker-ce
sudo systemctl status docker

now press q to come out this.
ps -ef | grep docker

docker --version

sudo docker run hello-world

the above command should display the below message..

you should see below message 

Hello from Docker!

This message shows that your installation appears to be working correctly.

Setup Docker Registry
Now we need to setup Docker registry. You have one of three options.

Option 1 - DockerHub as Docker Registry

Also, create an account(keep all lowercase in your username)  in the below website for storing docker images in public docker registry..

https://cloud.docker.com/
 
Option 2 - Configure Nexus as Docker Registry
Please click below link to configure Nexus as Docker Registry.
https://www.cidevops.com/2020/02/how-to-configure-nexus-as-docker.html

Option 3 - Configure AWS ECR as Docker Registry
Please click below link to configure Amazon ECR as Docker Registry.
https://www.cidevops.com/2020/05/how-to-setup-elastic-container-registry.html

 
Option 4 - Configure Azure Container Registry
Please click below link to configure ACR in Azure.
https://www.coachdevops.com/2019/12/how-to-upload-docker-images-to-azure.html

Microservices Introduction

https://www.cidevops.com/2017/01/what-is-microservices-all-about-best.html

Containerization is increasingly popular because containers are:

• Flexible: Even the most complex applications can be containerized.
• Lightweight: Containers leverage and share the host kernel.
• Interchangeable: You can deploy updates and upgrades on-the-fly.
• Portable: You can build locally, deploy to the cloud, and run anywhere.
• Scalable: You can increase and automatically distribute container replicas.
• Stackable: You can stack services vertically and on-the-fly.