K8s Commands & Implementation

Implementation - (CLI Install, Create Cluster, Deploy Cluster Namespaces, Pods, Deployments, Services)

Learning Outcome

Topic Name-Recall(Slide3)

Earlier we have seen:

• Kubernetes Architecture

• Pods

• Nodes

• Services

• Deployments

Now, we will implement these concepts practically

Real-World Operational Scenario

Imagine Kubernetes as a city manager

Cluster

Pods

Nodes

Namespace

Service

Real-World Operational Scenario

Real-World Operational Scenario

Real-World Operational Scenario

Real-World Operational Scenario

Real-World Operational Scenario

Real-World Operational Scenario

Real-World Operational Scenario

What is Kubernetes?

Kubernetes is an open-source container orchestration platform used to automate:

Ways to Use Kubernetes

Kubernetes can be used in 3 main ways:

1. Kind

• Runs Kubernetes clusters inside Docker

• Good for testing and CI/CD

2. Minikube

• Runs a single-node cluster locally

• Good for learning and development

3. Kubeadm

• Used to set up production-like clusters

• Manual configuration

Managed Kubernetes in Production

In real production environments, organizations use:

• Amazon EKS

• Azure AKS

• Google Kubernetes Engine

These services:

• Manage control plane automatically

• Provide high availability

• Offer security and scaling features

 Installing kubectl CLI

Below is the short and simple step-by-step guide to install Kubernetes using Kind on an Amazon EC2 instance

We are using:

• Kubernetes

• Kind

• Docker

• Amazon EC2

Install Kubernetes (Kind) on EC2 – Quick Steps

Step 1: Launch EC2 Instance

1. Go to AWS Console

2. Open Amazon EC2

3. Click Launch Instance

4. Choose:

• Amazon Linux 2 (or Ubuntu)

• t2.medium (recommended minimum)

​5. Allow Security Group:

• SSH (Port 22)​

6. Launch and connect via SSH

ssh -i key.pem ec2-user@your-public-ip

Step 2: Update System

sudo yum update -y

(For Ubuntu use sudo apt update -y)

Step 3: Install Docker

sudo yum install docker -y

sudo systemctl start docker

sudo systemctl enable docker

sudo usermod -aG docker ec2-user

Log out and log in again.

Verify: docker --version

Install Kubernetes (Kind) on EC2 – Quick Steps

Step 4: Install kubectl

curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"

chmod +x kubectl

sudo mv kubectl /usr/local/bin/

Verify: kubectl version --client

Step 5: Install Kind

curl -Lo ./kind https://kind.sigs.k8s.io/dl/latest/kind-linux-amd64

chmod +x kind

sudo mv kind /usr/local/bin/

Verify: kind --version

Done!

Now your Kubernetes cluster is running inside EC2 using Kind.

What is a Kubernetes Cluster?

A Cluster is a group of machines (nodes) running Kubernetes

It consists of:

• Control Plane

• Worker Nodes

Create Cluster Using Kind

kind create cluster --name dev-cluster

Check cluster:

kubectl cluster-info

kubectl get nodes

What is a Namespace?

A Namespace is a logical separation inside a cluster

Used to:

• Separate environments (dev, test, prod)

• Organize resources

Create Namespace

kubectl create namespace dev

Verify: kubectl get namespaces

What is a Pod?

A Pod is the smallest deployable unit in Kubernetes

• Contains one or more containers

• Runs on a node

Create Pod (YAML Example)

apiVersion: v1

kind: Pod

metadata:

  name: nginx-pod

spec:

  containers:

  - name: nginx

    image: nginx

Apply: kubectl apply -f pod.yaml

Check: kubectl get pods

What is a Deployment?

A Deployment manages pods and replicas

Features:

• Auto-scaling

• Self-healing

• Rolling updates

Create Deployment (YAML Example)

apiVersion: apps/v1

kind: Deployment

metadata:

  name: nginx-deployment

spec:

  replicas: 3

  selector:

    matchLabels:

      app: nginx

  template:

    metadata:

      labels:

        app: nginx

    spec:

      containers:

      - name: nginx

        image: nginx

Apply: kubectl apply -f deployment.yaml

Check: kubectl get deployments

What is a Service?

A Service exposes pods to internal or external traffic

Types:

• ClusterIP (default)

• NodePort

• LoadBalancer

Create Service (YAML Example)

apiVersion: v1

kind: Service

metadata:

  name: nginx-service

spec:

  type: NodePort

  selector:

    app: nginx

  ports:

  - port: 80

    targetPort: 80

    nodePort: 30007

Apply: kubectl apply -f service.yaml

Check: kubectl get services

What is a ReplicaSet?

A ReplicaSet ensures that a specified number of pod replicas are running at all times

If one pod crashes, ReplicaSet automatically creates a new one

Think of it like: “I always want 3 pods running — no matter what.”

Step 1 – Make Sure Kind Cluster is Running

kind create cluster --name dev-cluster

Verify: kubectl get nodes

What is a ReplicaSet?

apiVersion: apps/v1

kind: ReplicaSet

metadata:

  name: nginx-replicaset

spec:

  replicas: 3

  selector:

    matchLabels:

      app: nginx

  template:

    metadata:

      labels:

        app: nginx

    spec:

      containers:

      - name: nginx

        image: nginx

Save and exit.

Step 2 – Create ReplicaSet (YAML Method)

Create a file: nano replicaset.yaml

Step 3 – Apply ReplicaSet

kubectl apply -f replicaset.yaml

Step 4 – Verify ReplicaSet

Check ReplicaSet: kubectl get rs

Check Pods: kubectl get pods
You should see 3 running pods

 Step 5 – Test Self-Healing

Delete one pod: kubectl delete pod <pod-name>

Now check again: kubectl get pods

You will see a new pod automatically created
That’s ReplicaSet working!

What is a ReplicaSet?

Step 6 – Scale ReplicaSet

Increase replicas: kubectl scale rs nginx-replicaset --replicas=5

Verify: kubectl get pods

Step 7 – Delete ReplicaSet

kubectl delete rs nginx-replicaset

This will delete ReplicaSet and all pods it manages

Primary Kubernetes Objects Summary

Resource

Purpose

Cluster

Namespace

Pod

Deployment

Service

Collection of nodes

Logical isolation

Smallest deployable unit

Manages pods

Exposes application

Summary

 Kubernetes is mainly used for ?

 Kubernetes is mainly used for ?