Practical Examples on Advanced Beginner

Environment Setup

d8lzz1gpw@mozmail.com (kimbenji) — Sun, 11 Jan 2026 00:00:00 +0000

Target Audience: Developers who want to practice Kubernetes locally Prerequisites: Docker basics After reading this: You’ll be able to set up a local Kubernetes environment with Minikube or Kind

TL;DR

Minikube: Single node, recommended for beginners, rich addon support

Kind: Multi-node capable, suitable for CI/CD, fast cluster creation

Docker Desktop: Simplest setup for macOS/Windows

Local Kubernetes Options Comparison#

Tool	Pros	Cons	Best For
Minikube	Rich addons, extensive docs	Single node only	Learning, development
Kind	Fast, multi-node, CI-friendly	Fewer addons	CI/CD, testing
Docker Desktop	Easy installation	High resource usage	Quick start
k3d	Lightweight, fast	Different from production	Quick testing

Minikube Installation#

Install#

macOS

# Install via Homebrew
brew install minikube

# Check version
minikube version

Linux

# Download binary
curl -LO https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64

# Install
sudo install minikube-linux-amd64 /usr/local/bin/minikube

# Check version
minikube version

Windows

# Install via Chocolatey
choco install minikube

# Or manual installation
# https://minikube.sigs.k8s.io/docs/start/

Start Cluster#

# Start with default settings
minikube start

# Specify resources
minikube start --cpus=4 --memory=8192

# Use specific Kubernetes version
minikube start --kubernetes-version=v1.29.0

# Specify driver
minikube start --driver=docker

Available drivers:

Basic Example

d8lzz1gpw@mozmail.com (kimbenji) — Sun, 11 Jan 2026 00:00:00 +0000

Target Audience: Developers who want to practice Kubernetes core resources hands-on Prerequisites: Pod, Deployment, Service concepts After reading this: You’ll be able to create and manage Pod, Deployment, Service, and ConfigMap directly

TL;DR

Create Nginx Deployment and expose via Service

Inject configuration with ConfigMap

Practice rolling updates and rollbacks

Prerequisites#

You need:

Local Kubernetes cluster (Minikube or Kind)
kubectl

# Check cluster status
kubectl cluster-info

Exercise 1: Deployment and Service#

Create Deployment#

Deploy a web server.

Spring Boot Deployment

d8lzz1gpw@mozmail.com (kimbenji) — Sun, 11 Jan 2026 00:00:00 +0000

Target Audience: Backend developers who want to deploy Spring Boot applications to Kubernetes Prerequisites: Deployment, Service, ConfigMap, Docker After reading this: You’ll be able to containerize and deploy Spring Boot apps to Kubernetes

TL;DR

Write Dockerfile → Build image → Deploy to Kubernetes

Separate environment-specific configuration with ConfigMap/Secret

Configure health checks with Actuator endpoints

Overall Flow#

flowchart LR
 A[Spring Boot App] --> B[Dockerfile]
 B --> C[Docker Build]
 C --> D[Push Image]
 D --> E[K8s Deployment]
 E --> F[Service]
 F --> G[Ingress]

1. Prepare Spring Boot Application#

Example Application Structure#

my-app/
├── src/main/
│ ├── java/com/example/
│ │ └── MyAppApplication.java
│ └── resources/
│ └── application.yml
├── Dockerfile
├── build.gradle.kts
└── kubernetes/
 ├── deployment.yaml
 ├── service.yaml
 ├── configmap.yaml
 └── secret.yaml

application.yml#

spring:
 application:
 name: my-app
 datasource:
 url: ${DATABASE_URL:jdbc:postgresql://localhost:5432/mydb}
 username: ${DATABASE_USERNAME:postgres}
 password: ${DATABASE_PASSWORD:postgres}

server:
 port: 8080

management:
 endpoints:
 web:
 exposure:
 include: health,info,prometheus
 endpoint:
 health:
 probes:
 enabled: true
 health:
 livenessState:
 enabled: true
 readinessState:
 enabled: true

Simple Controller#

@RestController
public class HelloController {

 @GetMapping("/")
 public String hello() {
 return "Hello from Kubernetes!";
 }

 @GetMapping("/hostname")
 public String hostname() {
 try {
 return "Pod: " + InetAddress.getLocalHost().getHostName();
 } catch (UnknownHostException e) {
 return "Unknown";
 }
 }
}

2. Build Docker Image#

Dockerfile (Multi-stage Build)#

# Build stage
FROM eclipse-temurin:17-jdk AS build
WORKDIR /app
COPY gradle gradle
COPY build.gradle.kts settings.gradle.kts gradlew ./
COPY src src
RUN ./gradlew bootJar --no-daemon

# Runtime stage
FROM eclipse-temurin:17-jre
WORKDIR /app

# Security: use non-root user
RUN addgroup --system appgroup && adduser --system appuser --ingroup appgroup
USER appuser

COPY --from=build /app/build/libs/*.jar app.jar

EXPOSE 8080

ENTRYPOINT ["java", "-jar", "app.jar"]

Build Image#

# Build Docker image
docker build -t my-app:1.0 .

# Test locally
docker run -p 8080:8080 my-app:1.0

# Use local image in Minikube
eval $(minikube docker-env)
docker build -t my-app:1.0 .

# Use local image in Kind
kind load docker-image my-app:1.0

3. Write Kubernetes Resources#

ConfigMap (Environment Configuration)#

# kubernetes/configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:
 name: my-app-config
data:
 SPRING_PROFILES_ACTIVE: "kubernetes"
 DATABASE_URL: "jdbc:postgresql://postgres-service:5432/mydb"
 JAVA_OPTS: "-Xms256m -Xmx512m"

Secret (Sensitive Information)#

# Create Secret (command)
kubectl create secret generic my-app-secret \
 --from-literal=DATABASE_USERNAME=myuser \
 --from-literal=DATABASE_PASSWORD=mypassword

Or with YAML:

StatefulSet Hands-on

d8lzz1gpw@mozmail.com (kimbenji) — Mon, 23 Mar 2026 00:00:00 +0000

Target Audience: Developers who want to deploy stateful applications on Kubernetes Prerequisites: Deployment, Service, PersistentVolume concepts After reading this: You will be able to deploy MySQL with StatefulSet and verify data persistence

TL;DR

Deploy MySQL with StatefulSet

Access individual Pods via Headless Service

Persist data with PersistentVolumeClaim templates

Verify data preservation during scale up/down

Overall Flow#

flowchart LR
 A[Headless Service] --> B[StatefulSet]
 B --> C[mysql-0]
 B --> D[mysql-1]
 B --> E[mysql-2]
 C --> F[PVC-0]
 D --> G[PVC-1]
 E --> H[PVC-2]

Prerequisites#

You will need the following:

RBAC Configuration Lab

d8lzz1gpw@mozmail.com (kimbenji) — Mon, 23 Mar 2026 00:00:00 +0000

Target Audience: Developers/operators who want to configure access control for Kubernetes clusters Prerequisites: Namespace, Pod, Deployment concepts After reading this: You will be able to configure per-namespace access control using Role, RoleBinding, and ServiceAccount

TL;DR

Create a limited-permission Role for the development team

Create a ServiceAccount and bind it to the Role

Test permissions with kubectl auth can-i

Separate access permissions by namespace

RBAC Structure#

flowchart TD
 SA[ServiceAccount] -->|Binding| RB[RoleBinding]
 R[Role] -->|Reference| RB
 RB -->|Grant permissions| NS[Namespace Resources]

 SA2[ServiceAccount] -->|Binding| CRB[ClusterRoleBinding]
 CR[ClusterRole] -->|Reference| CRB
 CRB -->|Grant permissions| CL[Cluster-wide Resources]

Resource	Scope	Description
Role	Namespace	Permissions for resources within a specific Namespace
ClusterRole	Cluster	Permissions for cluster-wide resources
RoleBinding	Namespace	Bind Role/ClusterRole to subjects
ClusterRoleBinding	Cluster	Bind ClusterRole to subjects

Prerequisites#

You will need the following:

CronJob Lab

d8lzz1gpw@mozmail.com (kimbenji) — Mon, 23 Mar 2026 00:00:00 +0000

Target Audience: Developers who want to schedule periodic tasks on Kubernetes Prerequisites: Pod, Job concepts After reading this: You will be able to create periodic backup tasks with CronJob, and manage execution history and concurrency policies

TL;DR

Automate periodic data backups with CronJob

Manage execution history with successfulJobsHistoryLimit

Control concurrent execution with concurrencyPolicy

Configure failure alerts

CronJob Execution Flow#

flowchart TD
 CRON[CronJob Controller] -->|On schedule| JOB[Create Job]
 JOB --> POD[Run Pod]
 POD -->|Success| SUCCESS[Completion Record]
 POD -->|Failure| RETRY{Retry?}
 RETRY -->|Within backoffLimit| POD
 RETRY -->|Exceeded| FAIL[Failure Record]

 SUCCESS --> HIST[History Management<br>successfulJobsHistoryLimit]
 FAIL --> HIST2[History Management<br>failedJobsHistoryLimit]

Prerequisites#

You will need the following: