DevOps20 min read•November 7, 2024

Docker and Kubernetes: Complete Container Orchestration Guide for 2025

Master containerization with Docker and Kubernetes. Learn deployment strategies, best practices, and how to build scalable cloud-native applications.

Munir

Software Engineer specializing in modern web development with Next.js and React

Docker and Kubernetes: Complete Container Orchestration Guide for 2025

Containers have revolutionized application deployment, and Kubernetes has become the industry standard for container orchestration. This comprehensive guide covers everything you need to deploy production-grade containerized applications.

Understanding Containers

What are Containers?

Containers package applications with all dependencies into standardized units. Unlike virtual machines, containers share the host OS kernel, making them lightweight and portable.

Consistent environments (dev, staging, production)
Faster deployment (seconds vs. minutes)
Better resource utilization
Simplified scaling
Microservices enablement

Docker Fundamentals

Docker is the most popular container platform, powering over 75% of containerized applications.

**Images**: Read-only templates for containers
**Containers**: Running instances of images
**Dockerfile**: Instructions to build images
**Docker Hub**: Public image registry
**Volumes**: Persistent data storage
**Networks**: Container communication

Creating Your First Dockerfile

dockerfile

1# <span class="text-yellow-<span class="text-orange-400">300span>">Usespan> official base image
2<span class="text-yellow-<span class="text-orange-400">300span>">FROMspan> node:<span class="text-orange-400">18span>-alpine
3 
4# <span class="text-yellow-<span class="text-orange-400">300span>">Setspan> working directory
5<span class="text-yellow-<span class="text-orange-400">300span>">WORKDIRspan> /app
6 
7# <span class="text-yellow-<span class="text-orange-400">300span>">Copyspan> package files
8<span class="text-yellow-<span class="text-orange-400">300span>">COPYspan> package*.json ./
9 
10# <span class="text-yellow-<span class="text-orange-400">300span>">Installspan> dependencies
11<span class="text-yellow-<span class="text-orange-400">300span>">RUNspan> npm ci --only=production
12 
13# <span class="text-yellow-<span class="text-orange-400">300span>">Copyspan> application code
14<span class="text-yellow-<span class="text-orange-400">300span>">COPYspan> . .
15 
16# <span class="text-yellow-<span class="text-orange-400">300span>">Exposespan> port
17<span class="text-yellow-<span class="text-orange-400">300span>">EXPOSEspan> <span class="text-orange-400">3000span>
18 
19# <span class="text-yellow-<span class="text-orange-400">300span>">Setspan> <span class="text-blue-400">userspan>(security best practice)
20<span class="text-yellow-<span class="text-orange-400">300span>">USERspan> node
21 
22# <span class="text-yellow-<span class="text-orange-400">300span>">Startspan> application
23<span class="text-yellow-<span class="text-orange-400">300span>">CMDspan> [<span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">"node"span>, <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">"server.js"span>]

Use specific image tags (not latest)
Multi-stage builds for smaller images
Run as non-root user
Minimize layers
Use .dockerignore file
Scan for vulnerabilities

Docker Compose for Multi-Container Apps

yaml

1version: <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">'<span class="text-orange-400">3span>.<span class="text-orange-400">8span>'span>
2services:
3  web:
4    build: .
5    ports:
6      - <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">"<span class="text-orange-400">3000span>:<span class="text-orange-400">3000span>"span>
7    environment:
8      - NODE_ENV=production
9      - DB_HOST=database
10    depends_on:
11      - database
12      - redis
13    
14  database:
15    image: postgres:<span class="text-orange-400">15span>-alpine
16    volumes:
17      - postgres_data:/<span class="text-purple-<span class="text-orange-400">400span> font-semibold">varspan>/lib/postgresql/data
18    environment:
19      - POSTGRES_PASSWORD=secret
20    
21  redis:
22    image: redis:<span class="text-orange-400">7span>-alpine
23    ports:
24      - <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">"<span class="text-orange-400">6379span>:<span class="text-orange-400">6379span>"span>
25 
26volumes:
27  postgres_data:

Kubernetes Architecture

Control Plane Components

1API Server: Entry point for all operations
2etcd: Distributed key-value store (cluster state)
3Scheduler: Assigns pods to nodes
4Controller Manager: Maintains desired state
5Cloud Controller Manager: Cloud provider integration

Worker Node Components

1kubelet: Runs on each node, manages pods
2kube-proxy: Network proxy and load balancer
3Container Runtime: Docker, containerd, or CRI-O

Kubernetes Objects

Pod: Smallest deployable unit

yaml

1apiVersion: v1
2kind: <span class="text-yellow-<span class="text-orange-400">300span>">Podspan>
3metadata:
4  name: nginx-pod
5spec:
6  containers:
7  - name: nginx
8    image: nginx:<span class="text-orange-400">1span>.<span class="text-orange-400">25span>
9    ports:
10    - containerPort: <span class="text-orange-400">80span>

Deployment: Manages pod replicas

yaml

1apiVersion: apps/v1
2kind: <span class="text-yellow-<span class="text-orange-400">300span>">Deploymentspan>
3metadata:
4  name: web-app
5spec:
6  replicas: <span class="text-orange-400">3span>
7  selector:
8    matchLabels:
9      app: web
10  template:
11    metadata:
12      labels:
13        app: web
14    spec:
15      containers:
16      - name: app
17        image: myapp:<span class="text-orange-400">1span>.<span class="text-orange-400">0span>
18        resources:
19          limits:
20            memory: <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">"512Mi"span>
21            cpu: <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">"500m"span>
22          requests:
23            memory: <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">"256Mi"span>
24            cpu: <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">"250m"span>

Service: Exposes pods

yaml

1apiVersion: v1
2kind: <span class="text-yellow-<span class="text-orange-400">300span>">Servicespan>
3metadata:
4  name: web-service
5spec:
6  selector:
7    app: web
8  ports:
9  - port: <span class="text-orange-400">80span>
10    targetPort: <span class="text-orange-400">8080span>
11  <span class="text-purple-<span class="text-orange-400">400span> font-semibold">typespan>: <span class="text-yellow-<span class="text-orange-400">300span>">LoadBalancerspan>

ConfigMap & Secrets: Configuration management

yaml

1apiVersion: v1
2kind: <span class="text-yellow-<span class="text-orange-400">300span>">ConfigMapspan>
3metadata:
4  name: app-config
5data:
6  APP_ENV: production
7  LOG_LEVEL: info
8---
9apiVersion: v1
10kind: <span class="text-yellow-<span class="text-orange-400">300span>">Secretspan>
11metadata:
12  name: db-secret
13<span class="text-purple-<span class="text-orange-400">400span> font-semibold">typespan>: <span class="text-yellow-<span class="text-orange-400">300span>">Opaquespan>
14data:
15  password: cGFzc3dvcmQxMjM=  # base64 encoded

Deployment Strategies

Rolling Update

Zero downtime
Can rollback if issues detected
Gradual traffic shift

yaml

1spec:
2  strategy:
3    <span class="text-purple-<span class="text-orange-400">400span> font-semibold">typespan>: <span class="text-yellow-<span class="text-orange-400">300span>">RollingUpdatespan>
4    rollingUpdate:
5      maxSurge: <span class="text-orange-400">1span>
6      maxUnavailable: <span class="text-orange-400">0span>

Blue-Green Deployment

Deploy to green (new version)
Test thoroughly
Switch traffic to green
Keep blue as fallback

Canary Deployment

Deploy new version alongside old
Route 5% traffic to new
Monitor metrics
Increase percentage if stable
Full rollout or rollback

Production Best Practices

Resource Management

Always set resource limits:

yaml

1resources:
2  requests:
3    memory: <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">"256Mi"span>
4    cpu: <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">"250m"span>
5  limits:
6    memory: <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">"512Mi"span>
7    cpu: <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">"500m"span>

Health Checks

Implement liveness and readiness probes:

yaml

1livenessProbe:
2  httpGet:
3    path: /health
4    port: <span class="text-orange-400">8080span>
5  initialDelaySeconds: <span class="text-orange-400">30span>
6  periodSeconds: <span class="text-orange-400">10span>
7 
8readinessProbe:
9  httpGet:
10    path: /ready
11    port: <span class="text-orange-400">8080span>
12  initialDelaySeconds: <span class="text-orange-400">5span>
13  periodSeconds: <span class="text-orange-400">5span>

Autoscaling

Horizontal Pod Autoscaler:

yaml

1apiVersion: autoscaling/v2
2kind: <span class="text-yellow-<span class="text-orange-400">300span>">HorizontalPodAutoscalerspan>
3metadata:
4  name: web-app-hpa
5spec:
6  scaleTargetRef:
7    apiVersion: apps/v1
8    kind: <span class="text-yellow-<span class="text-orange-400">300span>">Deploymentspan>
9    name: web-app
10  minReplicas: <span class="text-orange-400">2span>
11  maxReplicas: <span class="text-orange-400">10span>
12  metrics:
13  - <span class="text-purple-<span class="text-orange-400">400span> font-semibold">typespan>: <span class="text-yellow-<span class="text-orange-400">300span>">Resourcespan>
14    resource:
15      name: cpu
16      target:
17        <span class="text-purple-<span class="text-orange-400">400span> font-semibold">typespan>: <span class="text-yellow-<span class="text-orange-400">300span>">Utilizationspan>
18        averageUtilization: <span class="text-orange-400">70span>

Security

Use RBAC for access control
Network policies for pod communication
Pod security policies/standards
Secret management (HashiCorp Vault)
Image scanning
Run as non-root
Read-only file systems

Monitoring and Logging

Prometheus + Grafana: Metrics ELK or Loki: Logging Jaeger: Distributed tracing

yaml

1# <span class="text-yellow-<span class="text-orange-400">300span>">ServiceMonitorspan> <span class="text-purple-<span class="text-orange-400">400span> font-semibold">forspan> <span class="text-yellow-<span class="text-orange-400">300span>">Prometheusspan>
2apiVersion: monitoring.coreos.com/v1
3kind: <span class="text-yellow-<span class="text-orange-400">300span>">ServiceMonitorspan>
4metadata:
5  name: web-app
6spec:
7  selector:
8    matchLabels:
9      app: web
10  endpoints:
11  - port: metrics
12    interval: 30s

Helm: Kubernetes Package Manager

Helm simplifies complex deployments:

bash

1# <span class="text-yellow-<span class="text-orange-400">300span>">Installspan> application
2helm install my-app ./chart
3 
4# <span class="text-yellow-<span class="text-orange-400">300span>">Upgradespan>
5helm upgrade my-app ./chart
6 
7# <span class="text-yellow-<span class="text-orange-400">300span>">Rollbackspan>
8helm rollback my-app <span class="text-orange-400">1span>

Chart Structure:

code

1my-chart/
2├── <span class="text-yellow-<span class="text-orange-400">300span>">Chartspan>.yaml
3├── values.yaml
4├── templates/
5│   ├── deployment.yaml
6│   ├── service.yaml
7│   └── ingress.yaml
8└── charts/

CI/CD with Kubernetes

GitOps with ArgoCD

Declarative, Git-based deployment: 1. Commit changes to Git 2. ArgoCD detects changes 3. Automatically syncs to cluster 4. Ensures desired state

Jenkins Pipeline

groovy

1pipeline {
2  agent any
3  stages {
4    <span class="text-blue-400">stagespan>(<span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">'<span class="text-yellow-<span class="text-orange-400">300span>">Buildspan>'span>) {
5      steps {
6        sh <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">'docker build -t myapp:tag .'span>
7      }
8    }
9    <span class="text-blue-400">stagespan>(<span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">'<span class="text-yellow-<span class="text-orange-400">300span>">Pushspan>'span>) {
10      steps {
11        sh <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">'docker push myapp:tag'span>
12      }
13    }
14    <span class="text-blue-400">stagespan>(<span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">'<span class="text-yellow-<span class="text-orange-400">300span>">Deployspan>'span>) {
15      steps {
16        sh <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">'kubectl apply -f k8s/'span>
17        sh <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">'kubectl rollout status deployment/myapp'span>
18      }
19    }
20  }
21}

Managed Kubernetes Services

AWS EKS (Elastic Kubernetes Service)

Managed control plane
Integrated with AWS services
Auto-scaling node groups
IAM integration

Google GKE (Google Kubernetes Engine)

Most feature-complete managed K8s
Autopilot mode (fully managed)
Best for Google Cloud ecosystem

Azure AKS (Azure Kubernetes Service)

Free control plane
Integrated with Azure services
Azure Active Directory integration
Virtual nodes (serverless)

Choosing a Platform

Use EKS if: Already on AWS, need deep AWS integration Use GKE if: Want best K8s experience, using Google Cloud Use AKS if: Microsoft ecosystem, Azure services Use Self-Managed if: Need complete control, regulatory requirements

Cost Optimization

1Right-size resources: Don't over-provision
2Use spot instances: Up to 90% savings
3Cluster autoscaling: Scale down when not needed
4Pod disruption budgets: Safe maintenance
5Namespace quotas: Prevent resource hogging

Common Pitfalls

1No resource limits: Causes node crashes
2Stateful apps in pods: Use StatefulSets
3Secrets in Git: Use secret management tools
4No health checks: Broken pods stay running
5Large images: Slow deployments
6Direct pod access: Always use services

Learning Path

Build images
Run containers
Docker Compose
Networking and volumes

Pods, Deployments, Services
kubectl commands
Local cluster (Minikube/kind)

StatefulSets, DaemonSets
ConfigMaps, Secrets
Ingress controllers
Persistent volumes

RBAC and security
Monitoring and logging
CI/CD pipelines
Helm charts

Conclusion

Docker and Kubernetes have become essential skills for modern software engineers. Containers provide consistency and portability, while Kubernetes offers powerful orchestration at scale.

Start by containerizing a simple application with Docker, then deploy it to a local Kubernetes cluster. Once comfortable with the basics, explore managed services like EKS, GKE, or AKS for production deployments.

The ecosystem is vast, but the core concepts remain consistent. Focus on fundamentals first, then expand to advanced topics like service meshes (Istio), serverless (Knative), and edge computing.

The future of application deployment is containerized, and Kubernetes is leading the way. The time to learn is now.

Tags:

DockerKubernetesContainersDevOpsCloud

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DevOps20 min read•November 7, 2024

Docker and Kubernetes: Complete Container Orchestration Guide for 2025

Master containerization with Docker and Kubernetes. Learn deployment strategies, best practices, and how to build scalable cloud-native applications.

Munir

Software Engineer specializing in modern web development with Next.js and React

Docker and Kubernetes: Complete Container Orchestration Guide for 2025

Understanding Containers

What are Containers?

Containers package applications with all dependencies into standardized units. Unlike virtual machines, containers share the host OS kernel, making them lightweight and portable.

Consistent environments (dev, staging, production)
Faster deployment (seconds vs. minutes)
Better resource utilization
Simplified scaling
Microservices enablement

Docker Fundamentals

Docker is the most popular container platform, powering over 75% of containerized applications.

**Images**: Read-only templates for containers
**Containers**: Running instances of images
**Dockerfile**: Instructions to build images
**Docker Hub**: Public image registry
**Volumes**: Persistent data storage
**Networks**: Container communication

Creating Your First Dockerfile

dockerfile

1# <span class="text-yellow-<span class="text-orange-400">300span>">Usespan> official base image
2<span class="text-yellow-<span class="text-orange-400">300span>">FROMspan> node:<span class="text-orange-400">18span>-alpine
3 
4# <span class="text-yellow-<span class="text-orange-400">300span>">Setspan> working directory
5<span class="text-yellow-<span class="text-orange-400">300span>">WORKDIRspan> /app
6 
7# <span class="text-yellow-<span class="text-orange-400">300span>">Copyspan> package files
8<span class="text-yellow-<span class="text-orange-400">300span>">COPYspan> package*.json ./
9 
10# <span class="text-yellow-<span class="text-orange-400">300span>">Installspan> dependencies
11<span class="text-yellow-<span class="text-orange-400">300span>">RUNspan> npm ci --only=production
12 
13# <span class="text-yellow-<span class="text-orange-400">300span>">Copyspan> application code
14<span class="text-yellow-<span class="text-orange-400">300span>">COPYspan> . .
15 
16# <span class="text-yellow-<span class="text-orange-400">300span>">Exposespan> port
17<span class="text-yellow-<span class="text-orange-400">300span>">EXPOSEspan> <span class="text-orange-400">3000span>
18 
19# <span class="text-yellow-<span class="text-orange-400">300span>">Setspan> <span class="text-blue-400">userspan>(security best practice)
20<span class="text-yellow-<span class="text-orange-400">300span>">USERspan> node
21 
22# <span class="text-yellow-<span class="text-orange-400">300span>">Startspan> application
23<span class="text-yellow-<span class="text-orange-400">300span>">CMDspan> [<span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">"node"span>, <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">"server.js"span>]

Use specific image tags (not latest)
Multi-stage builds for smaller images
Run as non-root user
Minimize layers
Use .dockerignore file
Scan for vulnerabilities

Docker Compose for Multi-Container Apps

yaml

1version: <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">'<span class="text-orange-400">3span>.<span class="text-orange-400">8span>'span>
2services:
3  web:
4    build: .
5    ports:
6      - <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">"<span class="text-orange-400">3000span>:<span class="text-orange-400">3000span>"span>
7    environment:
8      - NODE_ENV=production
9      - DB_HOST=database
10    depends_on:
11      - database
12      - redis
13    
14  database:
15    image: postgres:<span class="text-orange-400">15span>-alpine
16    volumes:
17      - postgres_data:/<span class="text-purple-<span class="text-orange-400">400span> font-semibold">varspan>/lib/postgresql/data
18    environment:
19      - POSTGRES_PASSWORD=secret
20    
21  redis:
22    image: redis:<span class="text-orange-400">7span>-alpine
23    ports:
24      - <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">"<span class="text-orange-400">6379span>:<span class="text-orange-400">6379span>"span>
25 
26volumes:
27  postgres_data:

Kubernetes Architecture

Control Plane Components

1API Server: Entry point for all operations
2etcd: Distributed key-value store (cluster state)
3Scheduler: Assigns pods to nodes
4Controller Manager: Maintains desired state
5Cloud Controller Manager: Cloud provider integration

Worker Node Components

1kubelet: Runs on each node, manages pods
2kube-proxy: Network proxy and load balancer
3Container Runtime: Docker, containerd, or CRI-O

Kubernetes Objects

Pod: Smallest deployable unit

yaml

1apiVersion: v1
2kind: <span class="text-yellow-<span class="text-orange-400">300span>">Podspan>
3metadata:
4  name: nginx-pod
5spec:
6  containers:
7  - name: nginx
8    image: nginx:<span class="text-orange-400">1span>.<span class="text-orange-400">25span>
9    ports:
10    - containerPort: <span class="text-orange-400">80span>

Deployment: Manages pod replicas

yaml

1apiVersion: apps/v1
2kind: <span class="text-yellow-<span class="text-orange-400">300span>">Deploymentspan>
3metadata:
4  name: web-app
5spec:
6  replicas: <span class="text-orange-400">3span>
7  selector:
8    matchLabels:
9      app: web
10  template:
11    metadata:
12      labels:
13        app: web
14    spec:
15      containers:
16      - name: app
17        image: myapp:<span class="text-orange-400">1span>.<span class="text-orange-400">0span>
18        resources:
19          limits:
20            memory: <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">"512Mi"span>
21            cpu: <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">"500m"span>
22          requests:
23            memory: <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">"256Mi"span>
24            cpu: <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">"250m"span>

Service: Exposes pods

yaml

1apiVersion: v1
2kind: <span class="text-yellow-<span class="text-orange-400">300span>">Servicespan>
3metadata:
4  name: web-service
5spec:
6  selector:
7    app: web
8  ports:
9  - port: <span class="text-orange-400">80span>
10    targetPort: <span class="text-orange-400">8080span>
11  <span class="text-purple-<span class="text-orange-400">400span> font-semibold">typespan>: <span class="text-yellow-<span class="text-orange-400">300span>">LoadBalancerspan>

ConfigMap & Secrets: Configuration management

yaml

1apiVersion: v1
2kind: <span class="text-yellow-<span class="text-orange-400">300span>">ConfigMapspan>
3metadata:
4  name: app-config
5data:
6  APP_ENV: production
7  LOG_LEVEL: info
8---
9apiVersion: v1
10kind: <span class="text-yellow-<span class="text-orange-400">300span>">Secretspan>
11metadata:
12  name: db-secret
13<span class="text-purple-<span class="text-orange-400">400span> font-semibold">typespan>: <span class="text-yellow-<span class="text-orange-400">300span>">Opaquespan>
14data:
15  password: cGFzc3dvcmQxMjM=  # base64 encoded

Deployment Strategies

Rolling Update

Zero downtime
Can rollback if issues detected
Gradual traffic shift

yaml

1spec:
2  strategy:
3    <span class="text-purple-<span class="text-orange-400">400span> font-semibold">typespan>: <span class="text-yellow-<span class="text-orange-400">300span>">RollingUpdatespan>
4    rollingUpdate:
5      maxSurge: <span class="text-orange-400">1span>
6      maxUnavailable: <span class="text-orange-400">0span>

Blue-Green Deployment

Deploy to green (new version)
Test thoroughly
Switch traffic to green
Keep blue as fallback

Canary Deployment

Deploy new version alongside old
Route 5% traffic to new
Monitor metrics
Increase percentage if stable
Full rollout or rollback

Production Best Practices

Resource Management

Always set resource limits:

yaml

1resources:
2  requests:
3    memory: <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">"256Mi"span>
4    cpu: <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">"250m"span>
5  limits:
6    memory: <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">"512Mi"span>
7    cpu: <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">"500m"span>

Health Checks

Implement liveness and readiness probes:

yaml

1livenessProbe:
2  httpGet:
3    path: /health
4    port: <span class="text-orange-400">8080span>
5  initialDelaySeconds: <span class="text-orange-400">30span>
6  periodSeconds: <span class="text-orange-400">10span>
7 
8readinessProbe:
9  httpGet:
10    path: /ready
11    port: <span class="text-orange-400">8080span>
12  initialDelaySeconds: <span class="text-orange-400">5span>
13  periodSeconds: <span class="text-orange-400">5span>

Autoscaling

Horizontal Pod Autoscaler:

yaml

1apiVersion: autoscaling/v2
2kind: <span class="text-yellow-<span class="text-orange-400">300span>">HorizontalPodAutoscalerspan>
3metadata:
4  name: web-app-hpa
5spec:
6  scaleTargetRef:
7    apiVersion: apps/v1
8    kind: <span class="text-yellow-<span class="text-orange-400">300span>">Deploymentspan>
9    name: web-app
10  minReplicas: <span class="text-orange-400">2span>
11  maxReplicas: <span class="text-orange-400">10span>
12  metrics:
13  - <span class="text-purple-<span class="text-orange-400">400span> font-semibold">typespan>: <span class="text-yellow-<span class="text-orange-400">300span>">Resourcespan>
14    resource:
15      name: cpu
16      target:
17        <span class="text-purple-<span class="text-orange-400">400span> font-semibold">typespan>: <span class="text-yellow-<span class="text-orange-400">300span>">Utilizationspan>
18        averageUtilization: <span class="text-orange-400">70span>

Security

Use RBAC for access control
Network policies for pod communication
Pod security policies/standards
Secret management (HashiCorp Vault)
Image scanning
Run as non-root
Read-only file systems

Monitoring and Logging

Prometheus + Grafana: Metrics ELK or Loki: Logging Jaeger: Distributed tracing

yaml

1# <span class="text-yellow-<span class="text-orange-400">300span>">ServiceMonitorspan> <span class="text-purple-<span class="text-orange-400">400span> font-semibold">forspan> <span class="text-yellow-<span class="text-orange-400">300span>">Prometheusspan>
2apiVersion: monitoring.coreos.com/v1
3kind: <span class="text-yellow-<span class="text-orange-400">300span>">ServiceMonitorspan>
4metadata:
5  name: web-app
6spec:
7  selector:
8    matchLabels:
9      app: web
10  endpoints:
11  - port: metrics
12    interval: 30s

Helm: Kubernetes Package Manager

Helm simplifies complex deployments:

bash

1# <span class="text-yellow-<span class="text-orange-400">300span>">Installspan> application
2helm install my-app ./chart
3 
4# <span class="text-yellow-<span class="text-orange-400">300span>">Upgradespan>
5helm upgrade my-app ./chart
6 
7# <span class="text-yellow-<span class="text-orange-400">300span>">Rollbackspan>
8helm rollback my-app <span class="text-orange-400">1span>

Chart Structure:

code

1my-chart/
2├── <span class="text-yellow-<span class="text-orange-400">300span>">Chartspan>.yaml
3├── values.yaml
4├── templates/
5│   ├── deployment.yaml
6│   ├── service.yaml
7│   └── ingress.yaml
8└── charts/

CI/CD with Kubernetes

GitOps with ArgoCD

Declarative, Git-based deployment: 1. Commit changes to Git 2. ArgoCD detects changes 3. Automatically syncs to cluster 4. Ensures desired state

Jenkins Pipeline

groovy

1pipeline {
2  agent any
3  stages {
4    <span class="text-blue-400">stagespan>(<span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">'<span class="text-yellow-<span class="text-orange-400">300span>">Buildspan>'span>) {
5      steps {
6        sh <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">'docker build -t myapp:tag .'span>
7      }
8    }
9    <span class="text-blue-400">stagespan>(<span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">'<span class="text-yellow-<span class="text-orange-400">300span>">Pushspan>'span>) {
10      steps {
11        sh <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">'docker push myapp:tag'span>
12      }
13    }
14    <span class="text-blue-400">stagespan>(<span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">'<span class="text-yellow-<span class="text-orange-400">300span>">Deployspan>'span>) {
15      steps {
16        sh <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">'kubectl apply -f k8s/'span>
17        sh <span <span class="text-purple-<span class="text-orange-400">400span> font-semibold">classspan>="text-green-<span class="text-orange-400">400span>">'kubectl rollout status deployment/myapp'span>
18      }
19    }
20  }
21}

Managed Kubernetes Services

AWS EKS (Elastic Kubernetes Service)

Managed control plane
Integrated with AWS services
Auto-scaling node groups
IAM integration

Google GKE (Google Kubernetes Engine)

Most feature-complete managed K8s
Autopilot mode (fully managed)
Best for Google Cloud ecosystem

Azure AKS (Azure Kubernetes Service)

Free control plane
Integrated with Azure services
Azure Active Directory integration
Virtual nodes (serverless)

Choosing a Platform

Cost Optimization

1Right-size resources: Don't over-provision
2Use spot instances: Up to 90% savings
3Cluster autoscaling: Scale down when not needed
4Pod disruption budgets: Safe maintenance
5Namespace quotas: Prevent resource hogging

Common Pitfalls

1No resource limits: Causes node crashes
2Stateful apps in pods: Use StatefulSets
3Secrets in Git: Use secret management tools
4No health checks: Broken pods stay running
5Large images: Slow deployments
6Direct pod access: Always use services

Learning Path

Build images
Run containers
Docker Compose
Networking and volumes

Pods, Deployments, Services
kubectl commands
Local cluster (Minikube/kind)

StatefulSets, DaemonSets
ConfigMaps, Secrets
Ingress controllers
Persistent volumes

RBAC and security
Monitoring and logging
CI/CD pipelines
Helm charts

Conclusion

Docker and Kubernetes have become essential skills for modern software engineers. Containers provide consistency and portability, while Kubernetes offers powerful orchestration at scale.

The ecosystem is vast, but the core concepts remain consistent. Focus on fundamentals first, then expand to advanced topics like service meshes (Istio), serverless (Knative), and edge computing.

The future of application deployment is containerized, and Kubernetes is leading the way. The time to learn is now.

Tags:

DockerKubernetesContainersDevOpsCloud

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