Getting Started with Kubernetes: A Practical Guide

Learn the fundamentals of Kubernetes — from cluster setup to deploying your first application with kubectl and YAML manifests.

Kubernetes has become the de facto standard for container orchestration. Whether you're managing a handful of microservices or scaling to thousands of pods, understanding the core concepts is essential for any DevOps engineer.

Prerequisites

Before diving in, make sure you have the following tools installed:

# 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 installation
kubectl version --client

For a local development cluster, I recommend using kind (Kubernetes in Docker):

# Install kind
go install sigs.k8s.io/kind@latest

# Create a cluster
kind create cluster --name dev

Core Concepts

Kubernetes revolves around a few key abstractions:

Pod — the smallest deployable unit, wrapping one or more containers
Deployment — declares the desired state for a set of pods
Service — stable networking endpoint for accessing pods
Namespace — logical isolation boundary within a cluster

Your First Deployment

Let's deploy a simple nginx application. Create a file called nginx-deployment.yaml:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx
  labels:
    app: nginx
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
        - name: nginx
          image: nginx:1.27-alpine
          ports:
            - containerPort: 80
          resources:
            requests:
              cpu: "50m"
              memory: "64Mi"
            limits:
              cpu: "100m"
              memory: "128Mi"

Apply it to your cluster:

# Apply the manifest
kubectl apply -f nginx-deployment.yaml

# Watch the rollout
kubectl rollout status deployment/nginx

# Check running pods
kubectl get pods -l app=nginx

Exposing the Service

To make nginx accessible, create a Service:

apiVersion: v1
kind: Service
metadata:
  name: nginx-svc
spec:
  selector:
    app: nginx
  ports:
    - port: 80
      targetPort: 80
  type: ClusterIP

# Apply the service
kubectl apply -f nginx-svc.yaml

# Port-forward to access locally
kubectl port-forward svc/nginx-svc 8080:80

Now open http://localhost:8080 and you should see the nginx welcome page.

What's Next

This is just the beginning. In upcoming posts we'll cover:

Helm charts for packaging applications
Ingress controllers and TLS termination
Monitoring with Prometheus and Grafana
GitOps workflows with ArgoCD

The key to mastering Kubernetes is practice. Spin up a local cluster and experiment — break things, fix them, and build your intuition.

Happy deploying!