What is the difference between Docker and Kubernetes?

Docker is a containerization engine used to package applications with their dependencies, while Kubernetes is a container orchestration platform that manages, scales, and automates container deployments across cluster nodes.

What is a Kubernetes Pod?

A Pod is the smallest deployable unit in Kubernetes that encapsulates one or more containers sharing storage and network resources.

Docker & Kubernetes DevOps Deployment Guide (2026)

1. Multi-Stage Dockerfile Best Practices

Building lightweight, production-ready Docker images requires Multi-Stage Builds. Separate your compilation stage (e.g. Maven/JDK) from the final minimal runtime image (e.g. JRE Alpine) to reduce image size from 800MB to under 150MB.

# Stage 1: Build Java Spring Boot Application
FROM maven:3.9.6-eclipse-temurin-17 AS builder
WORKDIR /app
COPY pom.xml .
COPY src ./src
RUN mvn clean package -DskipTests

# Stage 2: Production JRE Lightweight Image
FROM eclipse-temurin:17-jre-alpine
WORKDIR /app
COPY --from=builder /app/target/*.jar app.jar
EXPOSE 8080
ENTRYPOINT ["java", "-jar", "app.jar"]
      

2. Kubernetes Objects & Cluster Architecture

A. Kubernetes Deployment Manifest (deployment.yaml)

A Deployment manages replica sets of identical Pods, automatically replacing failed containers and supporting zero-downtime rolling updates.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: spring-boot-app
spec:
  replicas: 3
  selector:
    matchLabels:
      app: spring-boot
  template:
    metadata:
      labels:
        app: spring-boot
    spec:
      containers:
      - name: spring-boot
        image: manishkumar/spring-boot-app:v1.0
        ports:
        - containerPort: 8080
      

B. Kubernetes Service & LoadBalancer (service.yaml)

A Service provides a stable virtual IP address and DNS name to route network traffic to healthy Pods.

apiVersion: v1
kind: Service
metadata:
  name: spring-boot-service
spec:
  type: LoadBalancer
  ports:
  - port: 80
    targetPort: 8080
  selector:
    app: spring-boot
      

C. Essential kubectl Cheat Sheet

# Get Pods, Deployments & Services
kubectl get pods -o wide
kubectl get deployments
kubectl get services

# View Container Logs & Describe Pod Details
kubectl logs -f 
kubectl describe pod 

# Scale Deployment Replicas
kubectl scale deployment spring-boot-app --replicas=5
      

Kubernetes FAQ

Q1. How does Kubernetes achieve high availability?

Kubernetes monitors container health using Liveness and Readiness probes, automatically restarting crashed containers and rescheduling Pods across available worker nodes.

Q2. What is AWS EKS?

AWS Elastic Kubernetes Service (EKS) is a managed Kubernetes service that handles control plane management, master node backups, and security patching automatically.

Docker & Kubernetes Deployment Guide