Kubernetes Deployment Guide

Overview

Kubernetes orchestrates containerized applications at scale. Learn to deploy, scale, and manage applications with Kubernetes objects.

Core Concepts

• Pods: Smallest deployable unit
• Deployments: Manage pod replicas
• Services: Network access to pods
• Ingress: HTTP routing
• ConfigMaps/Secrets: Configuration management

Basic Deployment

# deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: web-app
spec:
  replicas: 3
  selector:
    matchLabels:
      app: web-app
  template:
    metadata:
      labels:
        app: web-app
    spec:
      containers:
      - name: web
        image: myapp:1.0.0
        ports:
        - containerPort: 3000
        env:
        - name: PORT
          value: "3000"

Expose with Service

# service.yaml
apiVersion: v1
kind: Service
metadata:
  name: web-app-service
spec:
  type: LoadBalancer
  selector:
    app: web-app
  ports:
  - protocol: TCP
    port: 80
    targetPort: 3000

Ingress Configuration

# ingress.yaml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: web-app-ingress
spec:
  rules:
  - host: example.com
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: web-app-service
            port:
              number: 80

Common Commands

# Apply configuration
kubectl apply -f deployment.yaml

# Check deployment status
kubectl get deployments
kubectl describe deployment web-app

# Scale deployment
kubectl scale deployment web-app --replicas=5

# View logs
kubectl logs -f deployment/web-app

# Port forward for testing
kubectl port-forward service/web-app-service 8080:80

Kubernetes can automatically scale applications based on CPU and memory usage.